Browse all practice questions for the Harr Microbiology Practice Test. Search by topic, open any question and review its full explanation, then test yourself in the practice quiz.

Harr Microbiology Practice Test 2026 – Your Comprehensive All-in-One Guide to Exam Success! course image
More practice questions

These questions are part of the practice quiz. Start practicing

  • Identify the mismatched bacterium and specimen pairing.
  • Xylose lysine deoxycholate (XLD) agar is selective for which type of bacteria?
  • Which Aspergillus species is the most common cause of pulmonary aspergillosis?
  • In which form are dimorphic molds found in infected tissue?
  • What organism should be suspected in a contractor who developed respiratory disease after inspecting an abandoned warehouse infested with rodents?
  • What type of media is typically used to culture dermatophytes?
  • What type of bacteria are small, Gram-negative rods that may indicate infection with HACEK organisms?
  • What is a common symptom associated with infections caused by pathogenic E. coli strains?
  • What is the primary function of phenylalanine deaminase in certain bacterial genera?
  • Which Neisseria species is typically found in the normal flora of the human throat?
  • Which of the following characteristics best describe Fusobacterium spp.?
  • Which of the following antibiotics is Group B streptococci resistant to?
  • Which group of tests best differentiates Helicobacter pylori and C. jejuni?
  • In hydatid disease, which classification correctly identifies the causative agent and its host?
  • Bacillus anthracis can be differentiated from Bacillus cereus by which of the following tests?
  • Which organism is characterized by large, α-hemolytic colonies on blood agar?
  • Which media is primarily used for the recovery of fecal pathogens?
  • What is the most appropriate screening media for Staphylococcus aureus in the nursery department?
  • Charcot-Leyden crystals in stool are thought to be formed from the breakdown products of which type of cells?
  • Which organism is responsible for causing primary atypical pneumonia?
  • What aspect of culture testing limits its use for Mycoplasma pneumoniae?
  • Which organism is characterized as an oxidase-positive, nonmotile gram-negative coccobacillus?
  • What organism is identified from a CSF sample growing gram-negative rods with positive ONPG and indole but negative motility?
  • Which test results after 3 weeks of incubation on Lowenstein-Jensen agar are consistent with Mycobacterium tuberculosis?
  • Which agar plate effectively supports the growth of Haemophilus species that require V factor?
  • A Corynebacterium species becomes a pathogen when it produces which of the following?
  • Which two mycobacteria are commonly isolated from subcutaneous skin and thrive at 30°C?
  • The mycelial form of Histoplasma capsulatum seen on agar resembles what structure?
  • Which parasite is responsible for eosinophilic meningoencephalitis with symptoms like fever and headache?
  • In a stool culture showing aerobic gram-negative rods, which organism is likely if the patient had pseudoappendicular syndrome?
  • Which swab is ideal for recovering Corynebacterium diphtheriae from the nasopharynx?
  • Which virus is implicated along with Epstein-Barr virus as a cause of infectious mononucleosis?
  • Which Enterobacteriaceae genus is typically resistant to colistin?
  • Which Staphylococcus species is most often recovered from cases of toxic shock syndrome?
  • What is the primary difference when staining Cystoisospora belli oocysts compared to traditional acid-fast bacilli (AFB) stains?
  • The B-galactosidase test is used to identify which species of Neisseria?
  • Which organism is incorrectly matched with its method of infection?
  • Which stain can be used to detect oocysts of Cryptosporidium spp. in stool specimens?
  • A culture from a dog bite wound grew a gram-negative, slender rod that is a facultative anaerobe. What is the most likely identification?
  • What type of colonies does Pseudomonas stutzeri produce?
  • What test differentiates Cardiobacterium hominis from Actinobacillus spp.?
  • In an immunocompromised patient with vancomycin-resistant, catalase-negative cocci isolated, what other organisms might be responsible?
  • Which organism is identified as resistant to penicillin and ampicillin based on the provided test results?
  • What organism is suggested if gram stain shows sulfur granules containing gram-positive rods?
  • What is the most probable identification of an organism showing the following results: Coagulase = + at 4 hours, coagulase = Neg at 18 hours, and Novobiocin = Sensitive?
  • What is the most likely organism in a stool culture with symptoms of dysentery from Mexico City?
  • Which mycobacterium of the M. tuberculosis complex fails to grow in culture and shows a 'croissant-like' morphology?
  • What indicates that a Brazilian patient with cardiac issues most likely died from Trypanosomiasis?
  • Which virus is the most common etiological agent of viral respiratory disease in infants and children?
  • Autofluorescence, which requires no stain, is recommended for identifying which of the following?
  • For which clinical specimens is the KOH direct mount technique for examination of fungal elements used?
  • What concentration of sodium hydroxide (NaOH) is used to prepare a working decontamination solution for mycobacteria?
  • What is a common symptom associated with infection from enteric pathogens such as Shigella?
  • Which biochemical tests would differentiate between Shigella spp. and E. coli given their similarities?
  • Which organism is indicated by the presence of a yellow pigment and positive nitrate reduction?
  • What complication can influenza virus lead to in the elderly?
  • What is the most likely cause of rash in a father exposed to his children with chickenpox?
  • Which is the most appropriate nonselective medium for the recovery of mycobacteria from a heavily contaminated specimen?
  • What is the most likely identification for a patient showing a budding yeast in blood cultures, with a negative germ tube test and positive urease test?
  • How can Hepatitis B virus be transmitted?
  • Which organism can agglutinate in Salmonella polyvalent antiserum and may be mistaken for Salmonella?
  • What is the use of trimethoprim-sulfamethoxazole (SXT) disks in relation to streptococci?
  • What is one of the main symptoms of a severe infection with Plasmodium falciparum?
  • Which protozoan organism has been linked to waterborne and foodborne outbreaks in the U.S.?
  • Which genera of Enterobacteriaceae are usually nonmotile at 36°C?
  • Which test group best differentiates Acinetobacter baumannii from Pseudomonas aeruginosa?
  • Cetrimide agar is primarily used for the selective isolation of which organism?
  • In Breakpoint Antimicrobial Drug Testing, what does S, I, and R indicate?
  • Which respiratory virus is most often associated with severe disease in young children and infants?
  • Which method is used for rapid identification of classic infection with M. tuberculosis?
  • Brucella spp. are known for causing which of the following conditions?
  • Is it true or false that cultures of parasites require no quality control compared to bacterial cultures?
  • What is the next step in diagnosing a patient with presumptive severe acute respiratory syndrome (SARS)?
  • Which organism is incorrectly matched with its characteristic?
  • In the ONPG test, what is primarily being distinguished?
  • Which species is known for causing disseminated infections in immunocompromised patients?
  • How can the subspecies Haemophilus influenza (biogroup) aegyptius be differentiated?
  • Which enzymes contribute to the virulence of Staphylococcus aureus?
  • Which specimen is least likely to yield Trichomonas vaginalis?
  • What type of infections are associated with the HACEK group of organisms?
  • In addition to coagulase, what factor significantly contributes to the pathogenicity of Staphylococcus aureus?
  • Which Mycobacterium species produces pigmented colonies in the dark (is a scotochromogen)?
  • Which test is primarily used to distinguish the Micrococcaceae family from the Streptococcaceae family?
  • Which virus most likely caused the deaths of organ recipients from a male donor after a fatal accident?
  • Care must be taken when identifying biochemical isolates of Shigella because of serological cross reactions with which organism?
  • A patient with >100,000 col/mL of a nonhemolytic, catalase-negative organism in urine culture is likely infected by which organism?
  • The yeast form of which dimorphic fungus appears as oval or elongate cigar shapes?
  • A chemotherapy patient with severe diarrhea has anaerobic gram-positive, spore-forming bacilli isolated. What is the correct identification based on the culture results?
  • Which organism is likely identified from a sputum culture producing gram-negative diplococci?
  • Tinea versicolor is a skin infection caused by which organism?
  • Staphylococcus saprophyticus can be differentiated from Staphylococcus epidermidis by its resistance to which antibiotic?
  • Which presumptive test is used for the identification of Pseudomonas species?
  • In an HIV-1 infection, what is the importance of CD4 lymphocyte quantitation?
  • What viral serological test should be performed on a 25-year-old male with symptoms similar to chronic fatigue syndrome when other tests are negative?
  • What virulence factor is most commonly associated with Pseudomonas aeruginosa?
  • Which test is critical for identifying an organism suspected of eukaryotic infection if the patient has been on antibiotics?
  • A rapidly growing nonseptate mold produced colonies resembling cotton candy. What is the most likely identification?
  • What method is primarily used to culture Mycoplasma hominis from genital specimens?
  • Which group of streptococci is known for producing erythrogenic toxins?
  • What is the most likely identification of mycobacteria isolated from a hospital hot water system that grew at 42C and was non-pigmented?
  • An immunosuppressed man with a military history is likely infected with which organism?
  • What test differentiates S. pneumoniae from viridans streptococci?
  • Which broth is used for the cultivation of anaerobic bacteria to detect volatile fatty acids?
  • What is the primary function of the methyl red (MR) test?
  • What should be done with a lymph node biopsy fixed in formalin submitted for AFB smear?
  • Which organism is identified based on growth as gram-negative rods resembling 'closed safety pins' in a patient with fever after a camping trip?
  • In the U.S., blood agar plates are commonly made using red blood cells from which animal?
  • In a clinical lab, which media is best used for the growth of Neisseria gonorrhoeae?
  • For a patient with increasing diarrhea, which diagnostic test combination is most relevant?
  • A purple slant and blackened butt in lysine iron agar (LIA) indicate which bacterium?
  • Which of the following Mycobacterium spp. would be most likely to grow on a MacConkey agar plate?
  • The mycelial form of which dimorphic mold produces thick-walled, rectangular, or barrel-shaped alternate arthroconidia?
  • What feature characterizes Staphylococcus epidermidis in clinical specimens?
  • In a culture from an intra-abdominal abscess producing orange-tan colonies, what is the most likely identification based on oxidase positive and DNase positive results?
  • What differentiates MacConkey agar from other culture media?
  • What reagents are used to develop the red color in the nitrate reduction test?
  • Individuals showing a positive purified protein derivative (PPD) skin test for M. tuberculosis are usually which of the following?
  • What condition might be indicated by the isolation of anaerobic gram-negative rods post-gallbladder surgery?
  • What is the preferred treatment for infections caused by Enterobacteriaceae?
  • What is the formalin-ether concentration procedure primarily used to demonstrate?
  • What is the main symptom associated with schistosomiasis?
  • Putrescine is an alkaline amine product of which bacterial enzyme?
  • Classification of viruses primarily relies on which aspect?
  • Cycloserine-cefoxitin-fructose agar (CCFA) is primarily used for the recovery of which bacterium?
  • Which organism's recovery is enhanced by cold enrichment of feces in phosphate-buffered saline?
  • Which agar is the standard choice for isolating Yersinia from stool specimens?
  • In an outbreak of diarrheal disease linked to a municipal water supply, what is the most likely causative agent?
  • Kligler iron agar (KIA) differs from triple-sugar iron agar (TSI) in which aspect?
  • Which two yeast isolates can be differentiated by arthroconidia production?
  • To differentiate the Morganella and Proteus genera, which group of tests is most effective?
  • Which organisms should be considered in a waterborne outbreak of diarrheal disease?
  • A positive Simmons citrate test is indicated by what color change in the medium?
  • Which organism likely caused the 'bulls-eye' colonies observed in a stool culture from a patient with enterocolitis?
  • What is the most likely identification for an organism that requires hemin and NAD for growth in a patient undergoing chemotherapy?
  • Which Clostridium species is most often recovered from a wound infection with gas gangrene?
  • What is the most significant factor in determining whether a blood culture is indicative of Yersinia enterocolitica?
  • A patient presenting with severe genital irritation and lesions tests negative for common STD pathogens. What should be the next line of testing?
  • In which biochemical category does Actinobacillus spp. fall?
  • Which condition is primarily caused by the organism Plasmodium?
  • Resistance to which antibiotic categorizes a strain of Staphylococcus aureus as MRSA?
  • What is the best specimen for recovery of mycobacteria from a sputum sample?
  • Which bacteria is indicated by a positive catalase and oxidase test alongside yellow pigment production?
  • The salt tolerance test (6.5% salt broth) is primarily used to identify which organism?
  • What organism is most commonly recovered as a gram-positive cocci from blood cultures of patients with endocarditis?
  • At what temperature does Mycobacterium marinum optimally grow on Lowenstein-Jensen agar?
  • Which species of Mycobacterium is diagnosed by means other than culture?
  • What is the most likely identification of a facultative anaerobe from a human bite wound culture that shows Gram-negative straight, slender rods?
  • Which biochemical tests are essential for identifying colorless colonies growing on MacConkey agar from a catheterized urine specimen?
  • What type of specimen is particularly tested with a KOH direct mount?
  • A gram-positive spore-forming bacillus producing a double zone of B-hemolysis on sheep-blood agar is presumptively identified as?
  • What do newer findings suggest about the pathogenicity of Blastocystis hominis?
  • Which genus of small gram-negative coccobacilli is associated mainly with animals but can infect humans?
  • Which rapid test differentiates Plesiomonas shigelloides from Shigella species?
  • Which medium can best differentiate Kingella kingae from Eikenella corrodens?
  • Which operculated cestode egg can be recovered from human feces?
  • Which organism may require sputum examination for diagnosis?
  • Strains of Staphylococcus species that exhibit resistance to beta-lactam antibiotics are referred to as what?
  • Which infection is commonly associated with respiratory symptoms post-seminar in a group of teachers due to a specific pathogen?
  • Which characteristic is associated with the rhabditiform larvae of Strongyloides stercoralis?
  • Which tests are most appropriate for identifying gram-positive cocci with alpha-hemolysis in a pneumonia patient?
  • What distinguishes the catalase test for mycobacteria from other bacteria?
  • What is the cause of the variation in colony types seen with fresh isolates of Neisseria gonorrhoeae?
  • Which organism is associated with vertically transmitted infections in pregnant women at risk for complications during delivery?
  • What type of cells are often misidentified as protozoa in a patient with diarrhea?
  • What species of Haemophilus hemolyzes horse erythrocytes and requires hemin and NAD for growth?
  • Which statement accurately describes an Entamoeba histolytic trophozoite?
  • Cysts of Iodamoeba butschlii are characterized by which feature?
  • A culture from a leg wound for a 70-year-old man indicated lactose-negative colonies on MacConkey agar. What is the most probable organism based on the biochemical reactions?
  • Chryseobacterium spp. are distinguished from Acinetobacter spp. by which two tests?
  • Specimens for virus culture should be transported in media containing which of the following?
  • What organism is most likely responsible for pneumonia in a patient with flulike symptoms after returning from the Southwestern United States?
  • What is the quellung test used to identify?
  • What is the appropriate specimen to diagnose a viral cause for hemorrhagic cystitis in an immunocompromised patient?
  • In the Kauffmann-White schema, what combined antigens are used for serological identification of Salmonella spp.?
  • Which biochemical test is needed to differentiate Burkholderia cepacia from S. maltophilia?
  • Yersinia pestis infections are most commonly found in which U.S. region?
  • What is the identification of staphylococci isolates that showed a positive tube test for free coagulase?
  • Which organism is identified by a bone marrow sample revealing small intracellular cells and showing a dimorphic growth phase?
  • Which of the following organisms are transmitted to animals and humans after a tick bite?
  • Which disease and diagnostic combination is likely for a transplant patient with increasing diarrhea?
  • Microsporidial infections can be confirmed using which of the following techniques?
  • What organism is likely responsible for a urinary tract infection in an immunocompromised patient based on the given tests?
  • Which of the following is NOT appropriate when attempting to isolate N. gonorrheae from a genital specimen?
  • Which virus can cause severe respiratory illness in infants?
  • How can Enterobacter sakazakii be differentiated from Enterobacter cloacae?
  • An organism cultured from the skin produces colonies displaying a cherry-red color on Sabouraud dextrose agar after 3-4 weeks and teardrop-shaped microconidia along the side of hyphae. What is the most likely identification?
  • What type of results does Geotrichum demonstrate on cornmeal Tween 80 agar?
  • For diagnosing Pneumocystis jirovecii in an immunocompromised patient, which specimen is preferred?
  • What is the most likely identification for a patient with a severe eye irritation caused by a gram-negative rod that tests positive for cytochrome oxidase?
  • Which streptococci would most likely show a positive reaction to bacitracin?
  • What type of specimen is most suitable for initial identification of invasive aspergillosis via soluble antigen testing?
  • Deoxycholate agar (DCA) is useful for the isolation of which group of bacteria?
  • What would one expect to see when examining stool material for Cytoisospora belli?
  • When should a patient on steroid therapy be closely monitored for Strongyloides stercoralis reactivation?
  • What property do Streptococcus species exhibit?
  • Which agar is specifically recommended for recovering Bordetella pertussis from nasopharyngeal specimens?
  • What results from accidental ingestion of eggs where the human becomes an intermediate host?
  • Which pathogenic Enterobacteriaceae should laboratories be capable of serotyping?
  • The miracidial hatching test is used to assess the viability of eggs from which organism?
  • Which nonpathogenic Mycobacterium species is often isolated from clinical specimens and known as the 'tapwater bacillus'?
  • Which Mycobacterium species is predominantly associated with pulmonary infections?
  • Which amino acids are essential for the growth of Francisella tularensis?
  • What is the main benefit of using a flexible calcium alginate swab for nasopharyngeal sampling?
  • Which organism is a yellow pigment-producing, oxidase positive, nonmotile organism that does not grow on MacConkey agar?
  • A patient with pneumonia has negative H2S and positive urease on culture, what is the likely organism?
  • What single test is most effective in separating Klebsiella oxytoca from K. pneumoniae?
  • What differentiates catalase-positive Staphylococcus species from others?
  • Which tests best distinguish Enterobacter aerogenes from Edwardsiella tarda?
  • Early ring stages of the fifth human malaria, Plasmodium knowlesi, closely resemble which of the following?
  • Which Enterobacteriaceae produces Shiga-like toxin primarily?
  • What characteristic differentiates Aeromonas spp. on selective enteric media?
  • Which tests are needed for further identification of a gram-positive cocci that is catalase negative and B-hemolytic in a pregnant woman?
  • What is the main reason E. coli cysts were barely visible on a permanent stained smear?
  • Haemophilus influenzae, which causes ocular infections, requires which factors in the primary medium for growth?
  • A culture and sensitivity test on a catheterized urine specimen showed a colony count of over 100,000 col/mL of gram-positive cocci. What is the likely pathogen?
  • Staphylococcus epidermidis is most commonly recovered from which of the following sources?
  • Which virus is associated with adult gastroenteritis from contaminated food and water?
  • What is the likely identification of a small, gram-negative coccobacillus that is indole positive and requires X factor for growth?
  • What is the most likely cause of encephalitis in a man who has been working in a garden with a lot of dead birds and high mosquito populations?
  • Based on specific biochemical tests, which group does not include Group A or B streptococci and shows sensitivity to SXT?
  • Which Mycobacterium species does not produce the enzyme required to convert niacin to niacin ribonucleotide?
  • Which susceptibility test identifies group A β-hemolytic streptococci?
  • In which department should a single tube of CSF obtained from a 12-month-old boy be submitted?
  • Why might both lactose-positive and lactose-negative colonies from stool culture need further testing for pathogens?
  • Approximately what percentage of group B streptococci can grow in 6.5% salt broth?
  • Which test is performed to confirm an infection with Clostridium botulinum?
  • What potential problems can occur when using EDTA anticoagulant and holding blood prior to preparation of thick and thin blood films?
  • Why is prompt diagnosis critical in cases of suspected viral encephalitis?
  • A cystic fibrosis patient’s sample shows mucoid growth on blood agar. What is the expected identification?
  • What atmospheric condition is required to recover Campylobacter species from selective agar?
  • An isolate from CSF growing on cornmeal agar produces specific structures. Which test should be performed next?
  • What clinical specimen should be examined for microfilariae in patients with eosinophilia and lymphadenopathy post travel to tropical regions?
  • Which organism is typically positive for B-galactosidase?
  • Which bacterial species is characterized by being β-hemolytic and a common cause of throat infections?
  • What is the most likely organism found in a bloody stool sample with certain biochemical results indicating non-lactose-fermenting colonies?
  • What does a positive CAMP test suggest in relation to streptococci?
  • What is a common outcome when β-lactamase is produced by Staphylococcus aureus?
  • What is the correct identification for an anaerobic gram-positive diphtheroid with specific results collected from blood culture?
  • Which Bacteroides species is noted for 'pitting' of the agar and is sensitive to penicillin 2-unit disks?
  • What is the most likely identification for the fungus found on the feet of a patient with a culture showing specific characteristics after 8 days?
  • Ascospores are formed by which yeast isolate?
  • Identify the incorrect match between method and its objective.
  • A 29-year-old male with skin ulcers and a poorly staining coccobacillus is indicative of which organism?
  • What characteristic distinguishes Streptococcus pneumoniae from other streptococci?
  • Which organism is primarily associated with the consumption of undercooked bear meat?
  • What infection can be caused by eating poorly cooked pork?
  • Which virus is responsible for causing common cold symptoms?
  • Which virus in the Reoviridae group causes gastroenteritis in infants and young children?
  • Visceral larva migrans is primarily associated with which organism?
  • A 25-year-old pregnant patient with vaginal irritation likely has vaginosis caused by which organism?
  • A patient exhibiting 'glanders-like' symptoms after open wounds is most likely infected with which organism?
  • Which test is considered the best for confirming a Chlamydia trachomatis infection in urine samples?
  • What tests should be performed to identify B-hemolytic colonies of gram-positive cocci from a newborn with skin eruptions?
  • Which is the medium of choice for the selective recovery of gram-negative anaerobes?
  • During urease production testing, ammonia reacts to form which of the following products?
  • What explains a positive RT-PCR for HIV-1 followed by a negative Western blot?
  • What type of ticks are primarily responsible for transmitting Ehrlichia and Anaplasma spp.?
  • Which antibiotic is typically avoided in treating infections caused by anaerobes?
  • Which organism is most likely identified in a 20-year-old female with gram-negative rods in blood cultures and urine samples, given the specific biochemical tests?
  • Which Clostridium species causes pseudomembranous colitis or antibiotic-associated colitis?
  • Which transport media is unsuitable for Neisseria gonorrhoeae cultures?
  • What do Babesia parasites morphologically resemble?
  • The manganous chloride-urea test is used to identify which organism?
  • Which organism is differentiated from Micrococcus spp. using furazolidone susceptibility testing?
  • Which organism cannot typically be transmitted in the laboratory under normal conditions?
  • Which organism is indicated by a catalase-positive, gram-positive short rod with remarkable motility and β-hemolysis?
  • Which organism is associated with immunodeficiency syndromes and melioidosis?
  • Which organism resonates with the tests noted for a vancomycin-resistant gram-positive coccobacillus isolated from blood?
  • Which virus is commonly tested for in stool samples from children showing symptoms of gastroenteritis?
  • Which is a common isolation medium for Actinobacillus spp.?
  • What is the optimal medium for recovering Brucella spp. from blood and bone marrow specimens?
  • Which species of Haemophilus is notably difficult to isolate from genital ulcers?
  • A Gram stain of a urethral discharge showing gram-negative diplococci indicates which organism?
  • What is responsible for the satellite growth of Haemophilus spp. around colonies of Staphylococcus and Neisseria spp. on sheep blood agar?
  • In infections with Taenia solium, what role do humans play?
  • Which two helminth eggs may resemble each other?
  • To identify Haemophilus haemolyticus and Haemophilus parahaemolyticus, which plates should be used?
  • What test can be performed to confirm the presence of a true negative reaction in the nitrate reduction test?
  • Lysostaphin is used to differentiate Staphylococcus from which other genus?
  • What type of virus is the hepatitis C virus?
  • Among the tests for identifying an enteric pathogen, which is the most appropriate given the culture results of clear colonies on differential media?
  • A complete stool culture procedure should routinely include media for isolating which of the following?
  • Which disease is incorrectly matched with its symptoms?
  • Which organism is identified using the urease test for ammonia production?
  • An isolate of E. coli recovered from the stool of a patient with severe bloody diarrhea should be tested for which sugar?
  • Brucella melitensis and Brucella abortus can be differentiated by their growth on media containing which two dyes?
  • What is the significance of discovering chlamydospores in a yeast culture?
  • Slime production is a characteristic associated with which Staphylococcus species?
  • A Mycobacterium species recovered from an AIDS patient showed negative results for niacin and Tween 80 hydrolysis. What is the most likely identification?
  • Based on the recorded results from a blood culture, what is the likely identification of large gram-positive bacilli with lecithinase positive?
  • After negative tests for several viruses, which viral test should be done in a young female with a sore throat and lymphadenopathy?
  • Which characteristic differentiates E. coli from Shigella species?
  • What is the recommended specimen for recovering Enterobius vermicularis in pediatric patients?
  • What is necessary for further testing of yeast from a catheterized patient following chemotherapy?
  • Which procedure is best for detecting motility in organisms?
  • What is the most likely identification for a pediatric patient with bloody diarrhea and a clear colony on MacConkey agar with sorbitol?
  • Which organism is the most common cause of mucormycosis infection in humans?
  • Cystine tryptic digest (CTA) media for Neisseria species should be inoculated and cultured in which of the following conditions?
  • Which organism is most often implicated in opportunistic infections in immunocompromised hosts, particularly seen with filamentous fungi in lung infections?
  • Which of the following is true regarding Cryptococcus neoformans?
  • What organism is associated with the transmission of Chagas disease?
  • Which group of tests assists in the rapid identification of the Enterobacteriaceae family?
  • How are one or more acid-fast bacilli (AFB) reported according to the American Thoracic Society?
  • What test results are expected to confirm the identity of a suspected anaerobic bacterial infection?
  • What does a positive result in the VP test indicate?
  • Which of the following is not a characteristic of anaerobic cocci?
  • What is the most probable presumptive identification for slender, slightly curved, beaded, red mycobacterial rods that grew buff-colored microcolonies in a serpentine pattern?
  • Which reaction indicates a presumptive identification of Enterococcus faecalis?
  • Which organism is identified as the causative agent of Lyme disease?
  • Toxic shock syndrome is most commonly attributed to infection with which organism?
  • Blastoconidia are the beginning of which structures?
  • Which condition indicates that humans are the accidental intermediate host after ingesting eggs?
  • What is the suspected organism in a nonimmunized child with cough and flu-like symptoms when a gram-negative coccobacillus is cultured from several media?
  • What specimens should be obtained to establish a diagnosis of Lyme borreliosis?
  • What is the heat-stable catalase result expected for Mycobacterium species that are positive at 68°C?
  • Fever, abdominal cramping, watery stools, and fluid and electrolyte loss preceding bloody stools is characteristic of shigellosis but may also result from an infection with:
  • What test is used to differentiate Micrococcus from Staphylococcus species?
  • The Hair Baiting Test is used to differentiate which two species of Trichophyton that produce red colonies on Sabouraud agar plates?
  • Which strain shows a weak or delayed bubbling reaction when using the Superoxol test?
  • What is the routine laboratory test for diagnosing Treponema pallidum infections?
  • Which Mycobacterium species is often mistaken for other Mycobacteria due to its atypical growth characteristics?
  • What gastrointestinal infections are most commonly caused by extended-spectrum B-lactamase (ESBL) producers?
  • What organism is identified by producing orange, waxy colonies and showing partial acid-fast staining?
  • What are the most appropriate screening tests to presumptively differentiate and identify nonfermentative gram-negative bacilli from the Enterobacteriaceae?
  • Which organism allows humans to serve as both the intermediate and definitive host?
  • Nutritionally variant streptococci (NVS) require specific nutrients. Which test fulfills this requirement?
  • Which organism is primarily responsible for cervical lymphadenitis in children?
  • An isolate produced a constriction that was interpreted as a positive germ tube, but Candida albicans was ruled out. Which of the following fungi is the most likely identification?
  • In the context of a central nervous system infection, the detection of which yeast is most clinically relevant?
  • Which isolates of the Enterobacteriaceae family most commonly produce extended-spectrum B-lactamase (ESBL)?
  • What characteristic is noted in a fungus if it is viable only in yeast phase?
  • What is the primary route of transmission for schistosomiasis in humans?
  • Which method is used to identify anaerobes aside from packaged microsystems?
  • What organism is likely identified in an elderly woman with suspected cat-scratch disease, characterized by a small, curved gram-negative bacillus?
  • What is the primary capsular serotype responsible for the majority of Haemophilus influenzae infections?
  • How do Mycobacteria appear when stained by the Ziehl-Neelsen or Kinyoun methods with a methylene blue counterstain?
  • What is a notable characteristic of Yersinia pestis?
  • In a urinary tract specimen, which interpretation fits the isolated B-hemolytic streptococci?
  • A gram-positive branching filamentous organism that stains positive with a modified acid-fast stain is likely:
  • Which test determines inducible clindamycin resistance in staphylococci and streptococci?
  • Which of the following Mycobacteria is NOT associated with skin infections?
  • A gram-positive coccus from a wound culture shows B-hemolytic colonies. The most likely identification is?
  • How can nonpathogenic Moraxella species be differentiated from Neisseria species?
  • A patient who consumed bear meat and had fever and myalgia is likely infected with what organism?
  • From a gastric ulcer biopsy, which organism is likely if curved, gram-negative bacilli that test positive for urease are cultured?
  • What is the identification of an anaerobic gram-positive bacillus found in a surgical site infection with noted sensitivity and resistance criteria?
  • The most noted differences between Pseudomonas aeruginosa and Stenotrophomonas maltophilia are:
  • Which of the following tests is routinely used to identify Staphylococcus aureus?
  • What is the small, single-stranded DNA virus known as the fifth childhood disease?
  • Which yeast produces only blastoconidia on cornmeal Tween 80 agar?
  • Kingella kingae infections are primarily associated with which condition?
  • What is the ideal temperature range for the recovery of M. marinum?
  • Which first-line antibiotics are used to treat classic tuberculosis and tested by disk diffusion method?
  • Which of the following is a key characteristic of the thick blood film?
  • In culture, Clostridium perfringens typically shows which characteristic?
  • A 69-year-old patient with a cough had a fungal culture revealing septate hyphae with dichotomous branching. What is the likely identification?
  • What pathogen is likely causing pneumonia and is confirmed by growth on buffered CYE agar with L-cysteine?
  • What procedure should be taken for a hunter bitten by a fox suspected of rabies?
  • Which medium is primarily used for the selective recovery of Neisseria gonorrhoeae?
  • What is the most likely identification of the organism in a patient with neurological difficulties and a cloudy CSF showing gram-positive long-beaded bacilli?
  • A pure culture from an immunosuppressed patient yielded an organism that is nonmotile and positive for indophenol oxidase. What is the likely identification?
  • Which organisms are used as controls for both rapid growers and slow growers of Mycobacterium?
  • What is the most rapid method for diagnosing a genital herpes simplex (HSV-2) infection?
  • The India ink stain is used as a presumptive test for the presence of which organism?
  • What is the specimen of choice for diagnosing food poisoning caused by Bacillus cereus?
  • Which parasite stage is immediately infective for humans on passage from the gastrointestinal tract?
  • Older developing stages (trophs, schizonts) of Plasmodium knowlesi resemble those of which species?
  • What test can differentiate Pseudomonas aeruginosa from other nonfermentative gram-negative bacilli?
  • What biochemical characteristic distinguishes Salmonella from C. freundii?
  • Which drug is considered the treatment of choice for a methicillin-resistant Staphylococcus aureus infection?
  • What is the correct identification for a catalase-negative, gram-positive coccus resembling staphylococci isolated from blood cultures of a patient with endocarditis?
  • For the identification of a yeast infection in a patient, which test would not support a diagnosis of Candida albicans?
  • What is the best method to determine if a boy has contracted rabies after exposure to wild raccoons?
  • What is the role of the tube coagulase test in differentiating staphylococci?
  • Which group of streptococci is primarily associated with a positive PYR test?
  • Colistin-nalidixic acid agar (CNA) is primarily utilized for the isolation of which type of bacteria?
  • Which characteristic differentiates Moraxella catarrhalis from other Neisseria species?
  • Obligate anaerobic gram-negative bacilli that do not form spores and grow well in bile are most likely which organism?
  • What is the most likely organism in a cancer patient’s blood cultures showing lactose-negative, motile, gram-negative rods before antibiotic therapy?
  • Which test is used to differentiate Chryseobacterium spp. and Burkholderia cepacia?
  • An India ink test revealed many encapsulated yeast cells in a centrifuged CSF sample. Which yeast caused the diagnosed meningitis?
  • Which M. avium complex (MAC) organism is the most frequently isolated from AIDS patients?
  • What is the best choice of test to differentiate Pseudomonas aeruginosa from Acinetobacter spp.?
  • Which genera are positive for phenylalanine deaminase?
  • A patient with asymptomatic amebiasis is found to possibly have Entamoeba dispar instead of the pathogenic species. What should be recommended?
  • What does the Superoxol test rapidly test for?
  • What spirochete is commonly detected in hematology laboratories before a physician suspects an infection?
  • A 24-hour unpreserved urine specimen is most useful for recovering which of the following?
  • What may indicate the presence of a coagulase-positive Staphylococcus in a culture?
  • What is the most likely organism recovered from a cat scratch that shows smooth gray colonies with no hemolysis and is both catalase and oxidase positive?
  • What end product of glucose fermentation does the Voges-Proskauer (VP) test detect?
  • Which biochemical test is not useful for distinguishing between Enterobacteriaceae and nonfermentative gram-negative bacilli?
  • Which Staphylococcus species, besides Staphylococcus aureus, also produces coagulase?
  • What organism is most likely identified from a culture of gram-negative rods with oxidase positive, glucose OF positive, and red pigment?
  • Which of the following is a common characteristic of microsporidia?
  • In a urine culture showing more than 100,000 col/mL, what test is best for differentiating S. epidermidis from S. saprophyticus?
  • Which Mycobacterium species, associated with tuberculosis in cattle, also causes tuberculosis in humans?
  • What is the most commonly used diagnostic method for identifying Lyme disease?
  • What is the minimum inhibition zone size indicating penicillin susceptibility for Streptococcus pneumoniae using an oxacillin disk?
  • What is the likely cause of diarrhea in a patient whose modified acid-fast stained fecal smear reveals round structures with variable staining?
  • Which medium is preferred for recovering Vibrio cholerae from stool specimens?
  • What is most commonly associated with massive hemolysis and central nervous system involvement?
  • What characteristic do Klebsiella pneumoniae and Enterobacter cloacae share that makes them similar in identification?
  • What are the most common causes of viral pneumonia in adults?
  • Which organism is most likely identified from the stool of a cystic fibrosis patient that exhibits mucoid colonies?
  • What test is the most appropriate for differentiating Bacillus anthracis from other Bacillus species?
  • Based on specific reactions, which organism is likely to be identified from a newborn's blood cultures?
  • In serological testing for Epstein-Barr virus, which of the following is least likely to help with diagnosis?
  • What is the most efficient confirmation method for Legionnaires' disease from a sputum sample?
  • A culture from a tropical fish store manager’s wound grew on Lowenstein-Jensen agar at 30C but not at 37C. What is the most likely identification?
  • After a nursing student accidentally stuck herself with a needle, what is the best course of action?
  • Cerebrospinal fluid (CSF) specimens that cannot be cultured immediately should be:
  • How do humans acquire infections with Diphyllobothrium latum adult worms?
  • Material from a fungus-ball infection produced colonies with a green surface on Sabouraud agar. Which Aspergillus spp. is most probably identified?
  • Which test would most likely confirm a diagnosis of giardiasis?
  • What is the appropriate media for culturing suspected Corynebacterium diphtheriae from a nasopharyngeal swab?
  • Which of the following tests best differentiates Shigella species from E. coli?
  • At which pH does the methyl red (MR) test become positive?
  • Which tests are used for the presumptive identification of Cryptococcus neoformans?
  • Given the carbohydrate reactions, which Neisseria species is most likely identified in a vaginal swab?
  • Which yeast enzyme is detected using birdseed (niger seed) agar?
  • Identify the organism in a post-surgical abdominal wound drainage showing anaerobic gram-negative bacilli and specific antibiotic resistance.
  • What is the virus associated with venereal and respiratory tract warts?
  • Which gram-negative diplococci can be presumptively identified from a positive oxidase test?
  • Which genera of the Enterobacteriaceae are known to cause diarrhea and are considered enteric pathogens?
  • Which yeast species typically has pseudohyphae and blastoconidia that are arranged along pseudohyphae?
  • Which Haemophilus species is commonly associated with conjunctivitis in children?
  • How does the presence of H2S affect lysine iron agar?
  • Which parasite is most likely causing symptoms in a transplant patient on steroids, originally from Central America?
  • What is a common result for viridans streptococci in the bile esculin test?
  • What organism likely causes meningitis in a neonate presenting with gram-negative straight rods and a yellow pigment on culture?
  • Cutaneous disease involving skin, hair, and nails usually indicates an infection with a?
  • What is the correct sequence for skin cleansing during the aseptic collection of blood cultures?
  • Prereduced and vitamin K1-supplemented blood agar plates are recommended for the isolation of which organisms?
  • What is the most likely organism from a dog bite wound that produces yellow colonies with fingerlike projections?
  • Which test is used for confirming the identity of a strain of Staphylococcus aureus?
  • Which method could be used to confirm influenza infection in a patient with acute respiratory distress?
  • Despite experiencing symptoms, a patient was negative for giardiasis after three stool exams. This could be due to what reason?
  • Which of the following is an incorrect match between symptoms and disease?
  • What is the best noncultural test for diagnosing Gardnerella vaginalis in a case of vaginosis?
  • What is the first step to be performed in the identification of an unknown yeast isolate?
  • Microsporidia have been primarily implicated in human disease in which type of patients?
  • A pink yeast isolate from a patient with AIDS has what likely identification given certain results?
  • What characteristic findings on a Gram stain smear suggest a diagnosis of Gardnerella vaginalis?
  • Which organism is known for producing beta-lactamases that may compromise treatment options?
  • Which of the following organisms will display lipase activity on egg yolk agar?
  • Which genus is known for its oxidase-negative, nonmotile characteristics?
  • What is the most likely identification of a bacterium that exhibits small yellow colonies on blood agar, is a Gram-negative curved fusiform rod, and is catalase positive?
  • What is the most probable identification of a nonmotile gram-negative coccobacillus from CSF that is positive for indophenol oxidase?
  • Which type of agar is used specifically for the selective growth of gram-positive cocci?
  • Which test is necessary to differentiate Mycobacterium scrofulaceum from another mycobacterium?
  • Microscopic examination of a fungus cultured from a patient with athlete's foot showed large, smooth-walled, club-shaped macroconidia appearing singly or in clusters. What is the most likely identification?
  • What is the correct identification of the causative organism in a severe outbreak of diarrhea following municipal water exposure?
  • In the stool culture of a patient with severe diarrhea, what does the presence of clear colonies on MacConkey agar indicate?
  • After returning from India, a patient with eosinophilia is most likely to have which clinical specimen and organism match?
  • Which of the following structures is invaded by the genus Trichophyton?
  • A nonfermenter recovered from an eye wound is oxidase positive, motile with polar monotrichous flagella, and grows at 42C. To which DNA homology group should this organism be classified?
  • Which Enterobacteriaceae are known to commonly produce hydrogen sulfide (H2S)?
  • What is the likely identification of a gram-negative rod cultured from a pneumonia patient?
  • Which organism is identified in a pregnant woman experiencing flu-like symptoms with a positive urine culture and a blood culture revealing a gram-positive short rod?
  • Which Mycobacterium species is characterized by positive urease and considered a photochromogen?
  • A sputum sample from a patient shows a growth of a lavender-green pigment. Which organism is most likely?
  • Which Pseudomonas species is usually associated with lung infections related to cystic fibrosis?
  • Which Microsporum species causes an epidemic form of tinea capitis in children?
  • Which Staphylococcus species is typically identified as coagulase negative and novobiocin sensitive?
  • Which pathogen is frequently overlooked due to its lactose fermenting capability?
  • What is the best method for recovering anaerobic bacteria from a deep abscess?
  • How long should Mycobacterium tuberculosis-positive cultures be retained by the lab after testing?
  • Which bacterial group is identified as growing well on agar containing 20% bile and resistant to kanamycin and vancomycin?
  • Decarboxylation of amino acids lysine, ornithine, and arginine results in which products?
  • The L-pyrrolidonyl-B-napthylamide (PYR) hydrolysis test is used for which group of streptococci?
  • What is commonly tested to differentiate Candida species?
  • Carbohydrate assimilation tests are conducted using media that are?
  • An organism that shows bottle-brush growth in stab culture is most likely:
  • What was identified in a Gram stain from a gum lesion that showed amoebae?
  • Which bacteria are commonly tested for in clinical samples to confirm anaerobic infections?
  • Which technique is used for the confirmation of infection with human immunodeficiency virus (HIV-1)?
  • To recover Chlamydia spp. from genital specimens, which procedure is appropriate?
  • Which of the following characteristics is true for the Enterobacteriaceae family?
  • What is the best medium for the recovery of Legionella pneumophila from clinical specimens?
  • What is a common method for presumptive identification of yeast infections in clinical samples?
  • What is the primary test for differentiating Aeromonas spp. from the Enterobacteriaceae?
  • Identification of Clostridium tetani is primarily based on which method?
  • What organism is identified in blood cultures from a septic patient who received packed RBCs?
  • Which organism is known to produce 'fried-egg' colonies on agar?
  • All of the following are examples of appropriate specimens for the recovery of fungi except:
  • The yeast form of which dimorphic mold shows a large parent yeast cell surrounded by smaller budding yeast cells?
  • If a staphylococcus spp. is negative for the slide coagulase test and novobiocin resistance, what should be performed next?
  • What organism likely causes white patches on the tongue of a healthy 2-month-old infant?
  • Which organism is frequently confused with Salmonella species?
  • How long should iodine or iodophor remain on the skin when preparing for blood culture collection?
  • After isolating Staphylococcus aureus from a diabetic patient showing methicillin resistance, which additional antibiotic should be tested for susceptibility?
  • What is the significance of detecting beta-hemolysis on blood agar when diagnosing for Gardnerella vaginalis?
  • What should the follow-up test be for cultured bacteria from a patient with alpha-hemolytic pneumonia?
  • Which organism is characterized by spherules containing endospores found in a sputum specimen?
  • Which virus is primarily responsible for the symptoms of chickenpox?
  • Primary infections with microsporidia may originate in which part of the body?
  • Key characteristics of infection with Plasmodium knowlesi include which of the following?
  • What patient information is essential when malaria smears are requested?
  • A patient exhibits symptoms including fever and bloody stools 10 to 12 hours after eating. Which organisms are most likely to grow from this patient's stool culture?
  • What type of stain can be used to observe the presence of bacteria in leukocytes for diagnosis?
  • What type of staining method is often employed to visualize mycobacteria?
  • Cornmeal agar with Tween 80 is used to identify which characteristic of an unknown yeast isolate?
  • What is one potential serious outcome of untreated genital herpes simplex virus infection?
  • Which test is used to differentiate viridans streptococci from group D streptococci and enterococci?
  • Which of the following enzymatic tests is used to identify enterococci?
  • A patient returning from Africa has low-grade fever and malaise. What information is crucial for malaria testing?
  • What was the most likely cause of death for the newborn treated with acyclovir who did not survive?
  • What finding can lead to a presumptive diagnosis of Gardnerella vaginalis?
  • What characteristic is most commonly associated with Haemophilus influenzae strains that are resistant to ampicillin?
  • Regarding organisms and their characteristics, which match is incorrect?
  • Which test differentiates Cedeccea from Serratia species?
  • Chlamydospore production is demonstrated by which species of Candida?
  • Which of these organisms is primarily associated with necrotizing fasciitis?
  • What does a positive result on birdseed agar suggest?
  • Which Pseudomonas species is associated with exotoxin A and production of alginate?
  • Which group of organisms should be screened for B-lactamase production prior to susceptibility testing?
  • What virus is most likely responsible for gastrointestinal illness on a cruise ship?
  • What is the primary characteristic of S. pneumoniae when subjected to the bile solubility test?
  • Which of the following is an incorrect match between organism and diagnostic procedure?
  • Which tests are most appropriate to differentiate between Pseudomonas aeruginosa and Pseudomonas putida?
  • Eye infections caused by Acanthamoeba spp. have been most commonly traced to which factor?
  • What is the most likely identification of a yeast isolate from a diabetic patient’s sputum?
  • Which trichophyton species causes the favus type of tinea capitis seen in the Scandinavian countries and in the Appalachian region of the United States?
  • Which organisms should be considered in a nursery school outbreak of diarrhea?
  • Which organism is primarily responsible for cysticercosis in humans?
  • What is the likely identification of a sputum culture from a cystic fibrosis patient that grew a predominance of oxidase-negative, short gram-negative rods?
  • A rapidly growing hyaline mold began as a white colony but soon developed a black 'pepper' effect on the agar surface. What is the most likely identification?
  • What is the most likely identification for an oxidase-positive gram-negative rod with specific biochemical results indicating V. parahaemolyticus?
  • Which reagent is used to detect the presence of indole?
  • What is the most sensitive recovery method for Acanthamoeba spp. from lens care solutions?
  • In a patient with severe diarrhea who ate a hamburger, which pathogen corresponds to the specific culture results indicative of E. coli O157:H7?
  • What is a clinical test used for detecting viral infections other than culture?
  • Which species of Shigella is most commonly associated with diarrheal disease in the United States?
  • Identify the incorrect organism combination.
  • Which microfilariae are usually not found circulating in the peripheral blood?
  • Anaerobic bacteria are routinely isolated from all of the following types of infections except:
  • What animal harbors the adult tapeworm of Echinococcus granulosus?
  • A 3-year-old who experienced vomiting and diarrhea should have a stool sample tested for which virus?
  • Based on laboratory tests, what is the most likely identification of the organism from the blood cultures of a diabetic patient?
  • In addition to motility, which test best differentiates Acinetobacter spp. from Alcaligenes spp.?
  • Why is it important to maintain iodine on the skin for at least 60 seconds during blood culture preparation?
  • What characteristic color indicates Vibrio cholerae on TCBS agar?
  • Which dimorphic fungus exhibits a filamentous mold form at room temperature and converts to yeast form above 35C?
  • What is the purpose of adding sodium polyanetholsulfanate (SPS) to nutrient broth media for blood cultures?
  • Chocolate agar and modified Thayer-Martin agar are used for the recovery of which bacteria?
  • Which dematiaceous mold forms flask-shaped phialides, each with a flask-shaped collarette?
  • What test is performed to check the capability of an organism to utilize sodium malonate?
  • What is the best medium for recovery and identification of V. cholerae from a symptomatic patient returning from South America?
  • A culture showing short gram-positive bacilli with no hemolysis and negative catalase suggests which organism?
  • Which structure do Chlamydospores primarily indicate in yeast?
  • What features would help identify an organism as Burkholderia cepacia?
  • Which test result is NOT associated with the identification of Enteroinvasive E. coli (EIEC)?
  • In a patient with suspected bacterial vaginosis, which organism is typically isolated if lactobacilli are significantly decreased?
  • What characteristic differentiates yeasts from molds?
  • Which type of fungal infection is known to commonly occur in immunocompromised individuals?
  • Which two tests are negative for Mycobacterium avium-intracellulare complex?
  • What is the most likely identification of a non-spore-forming, slender gram-positive rod found in a vaginal culture?
  • What mechanism is responsible for botulism in infants caused by Clostridium botulinum?
  • The gram-positive non-spore-forming anaerobic rods most frequently recovered from blood cultures as a contaminant are:
  • Which pathogen requires 'enteric precautions' to prevent nosocomial infections in patients with severe diarrhea?
  • Antimicrobial susceptibility testing of anaerobes is done by which method?
  • Which organism causes bacterial vaginosis, as indicated by the presence of 'clue cells' and a fishy odor?
  • Which group of β-hemolytic streptococci is identified using a bacitracin A disk?
  • Which Mycobacterium species is best differentiated by the rapid hydrolysis of Tween 80?
  • Burkholderia pseudomallei is associated with which of the following diseases?
  • The direct spread route of pneumonic plague disease is through what means?
  • Which feature is characteristic of Mycobacterium tuberculosis in a laboratory setting?
  • A hyaline mold recovered from a patient with AIDS produced rose-colored colonies with lavender centers on Sabouraud dextrose agar. What is the most likely identification?
  • Which test differentiates Staphylococcus aureus from Staphylococcus intermedius?
  • A Vietnam War veteran with symptoms of melioidosis is likely to be infected with which organism?
  • What indicates a positive result for a nitrate reduction test in mycobacteria?
  • The δ-ALA test is confirmatory for the identification of which requirement in Haemophilus species?
  • A mold that produces colonies with a dark brown, green-black, or black appearance on both the surface and reverse side is classified as what type?
  • Which two tests are best for differentiating S. bovis from Streptococcus salivarius?
  • What are key characteristics of Toxoplasma gondii?
  • Which antibiotic is used in the Optochin disk test to differentiate S. pneumoniae?
  • A lactose-negative gram-negative rod that tests positive for indole and urease is likely which organism?
  • Which test is recommended for initial differentiation of Listeria monocytogenes from group B streptococci?
  • For a presumptive diagnosis of gonorrhea, which criteria must be present from an exudate?
  • Which of the following is NOT a common testing method for diagnosing Lyme disease?
  • What further testing should be done for a 6-month-old infant diagnosed with respiratory infection and apnea when bacterial cultures are negative?
  • Which organism, commonly found in fecal flora, can be confused with Yersinia due to biochemical similarities?
  • Which spore type and location is found on Clostridium tetani?
  • Which mycobacterium is associated with Crohn's disease?
  • What is the primary mode of transmission for dermatophyte infections?
  • Which gram-negative bacilli produce black pigment and brick red fluorescence when exposed to an ultraviolet light source?
  • Which organism is indicated by a catalase-positive, gram-positive coccus that grew pale yellow colonies on blood agar from a patient with impetigo?
  • What type of hemolysis is often produced by Staphylococcus aureus on blood agar?
  • What is used for preventing the growth of yeast and molds from vaginal specimens in culture?
  • Which organism is indicated by thin, nonpigmented anaerobic gram-negative rods found on anaerobic blood agar with specific growth characteristics?
  • What is the best technique to identify Dientamoeba fragilis in stool?
  • Alcaligenes faecalis can be distinguished from Bordetella bronchiseptica using which test?
  • What thermodimorphic fungus is identified by rapidly growing mold at 25C with specific conidiophores under microscopy?
  • Which virus has a 90% transplacental infection rate when found in an infected mother?
  • What color change indicates the presence of β-hemolysis, used to differentiate certain Haemophilus species?
  • Which services for mycobacteria are performed by a Level II laboratory according to CAP guidelines?
  • In which situation might a false-positive CAMP test for group B streptococci occur?
  • Which organism can be cultured from the upper and lower respiratory tract but commonly diagnosed by changes in antibody titer?
  • What is the most reliable method for confirming Mycoplasma pneumonia in serum?
  • What organism is indicated by 'cup-shaped' cysts found in the lung biopsy of an immunocompromised patient?
  • According to the American Thoracic Society's definition, what level of service does a lab providing acid-fast staining and inoculation cultures fall under?
  • What is the most likely organism following a leg culture that shows gram-negative rods on MacConkey agar with the given biochemical results?
  • An organism that is positive with a modified acid-fast stain and recovered from a sputum specimen is likely which of the following?
  • Which antibody's titer indicates a recent infection with group A β-hemolytic streptococci?
  • In terms of morphology, what is a distinguishing feature of the genus Candida?
  • Which Enterobacteriaceae species are often tested for their ability to ferment sorbitol?
  • In a 1-month-old infant with suspected meningitis, which preliminary tests would help differentiate L. monocytogenes from Streptococcus spp.?
  • Which parasite is known to cause a significant public health concern due to its association with a potentially fatal condition called blackwater fever?
  • Why is PCR testing preferred for Chlamydia trachomatis detection?
  • Fecal immunoassays are commonly used to diagnose infections with which organisms?
  • Before initiating antiviral therapy in an HIV-1 patient diagnosed by enzyme immunoassay and confirmed by Western blot, which laboratory test should be performed?
  • In parasitology, what is considered a STAT procedure?
  • Should a 24-hour urine specimen for mycobacteria culture be accepted if submitted by a 65-year-old female outpatient?
  • What is the role of serotyping in clinical labs regarding Enterobacteriaceae?
  • Which yeast species is characterized by a pink color and is germ tube-negative?
  • Which test result indicates a positive reaction for an organism that is catalase-negative and associated with endocarditis?
  • What organism is indicated when a blood culture shows gram-positive cocci and sensitivity to vancomycin?
  • What test rapidly differentiates Micrococcus from Staphylococcus?
  • Given a mixture of slender gram-negative rods and coccobacilli after surgery, what is the likely organism if catalase is negative and oxidase is positive?
  • Egg yolk agar is used to detect which enzyme produced by Clostridium species?
  • How are Micrococcus species typically characterized based on oxidase reactions?
  • Obligate anaerobes, facultative anaerobes, and microaerophiles are terms referring to bacteria that require:
  • Which two tests are best to differentiate A. hydrophilia from P. shigelloides?
  • Non-A and non-B β-hemolytic streptococci generally show which reactions to bacitracin and SXT?
  • What does a positive slide coagulase test for Staphylococcus aureus indicate?
  • A 12-year-old girl is brought to the emergency department with meningitidis. What motile amoeba is likely found in the CSF?
  • The classic form of foodborne botulism is characterized by the ingestion of what?
  • The malonate test is most useful in differentiating which members of the Enterobacteriaceae?
  • Growth inhibition by thiophene-2-carboxylic hydrazid (T2H) differentiates M. tuberculosis from which Mycobacterium species?
  • A patient diagnosed with colon malignancy has blood cultures showing anaerobic gram-positive bacilli. What is the organism based on the described results?
  • What most affects the oxidation-reduction potential (Eh or redox potential) of media for anaerobic bacteria?
  • Which bacterial characteristic can differentiate Enterobacter from Klebsiella spp.?
  • Which of the following genera are anaerobic cocci that stain gram positive?
  • Which parasitic organism is commonly transmitted through sexual contact?
  • A sheep blood agar plate is used as a primary isolation medium for all the following organisms except:
  • Which yeast is characteristically positive for germ tube production?
  • Which Haemophilus species is most commonly associated with endocarditis?
  • Based on culture results from a burn patient, what organism is indicated by the presence of oxidase positive and resistant to penicillin?
  • The bile solubility test primarily targets which species of Streptococcus?
  • What test would you perform last to differentiate Enterobacteriaceae based on urease activity?
  • What is the most distinguishing feature between E. coli and Shigella based on their biochemical reactions?
  • Which organism likely matches with a direct smear from a nasopharyngeal swab revealing metachromatic granules?
  • What effect does sodium polyanetholsulfanate (SPS) have on bacterial recovery during blood culture?
  • What is the most common viral syndrome associated with pericarditis, myocarditis, and pleurodynia?
  • What is the significance of the 'molar teeth' appearance on blood agar?
  • Which group of molds can be ruled out when septate hyphae are observed in a culture?
  • Which organism is likely identified from a gram-negative S-shaped rod grown at 42°C with positive oxidase and catalase tests?
  • What type of staining is utilized to visualize Nocardia species under a microscope?
Subscribe

Get the latest from Examzify

You can unsubscribe at any time. Read our privacy policy