[Q18-Q35] Exam Passing Guarantee Nov 26, 2025 ABMM Exam with Accurate Quastions!

NO.18 An acid-fast bacillus isolate recovered from a respiratory specimen after 3 weeks of incubation on Löwenstein- Jensen medium is initially non-pigmented when grown in the dark. After exposure to light for several hours, the colonies develop a distinct yellow-orange pigment. This organism is classified as a:

NO.19 Metagenomic analysis of a bronchoalveolar lavage (BAL) sample from a patient with severe pneumonia reveals a complex microbial community with a high abundance of both bacterial and fungal sequences. This approach is particularly useful in identifying:

NO.20 A microbiology laboratory receives a blood culture from a patient with suspected bacterial endocarditis. After
24 hours of incubation, Gram-positive cocci in clusters are observed on the Gram stain. Catalase test is positive, and coagulase test is negative. Further testing reveals susceptibility to novobiocin. The MOST likely organism is:

NO.21 A research laboratory is investigating the mechanisms of antigenic variation in Trypanosoma brucei, the causative agent of African trypanosomiasis. The parasite evades the host immune response by periodically changing its surface coat protein. This process primarily involves:

NO.22 A Klebsiella pneumoniae isolate from a bloodstream infection shows the following susceptibility profile:
Meropenem (MIC = 8 µg/mL, R), Imipenem (MIC = 16 µg/mL, R), Ertapenem (MIC = 4 µg/mL, R), Ceftazidime/avibactam (MIC = 1 µg/mL, S), Aztreonam (MIC = 32 µg/mL, R). Which resistance mechanism is most strongly suggested by this pattern?

NO.23 A patient presents with a chronic cough, weight loss, and night sweats. Chest X-ray shows cavitarylesions in the upper lobes. Sputum is acid-fast positive. Drug susceptibility testing reveals resistance to isoniazid but susceptibility to rifampin, ethambutol, and pyrazinamide. The MOST appropriate treatment regimen should include:

NO.24 A patient with a history of recurrent sinopulmonary infections and bronchiectasis is diagnosed with primary ciliary dyskinesia. Sputum cultures are most likely to persistently grow which of the following organisms?

NO.25 A microbiology laboratory receives a sample of cerebrospinal fluid from a patient with suspected bacterial meningitis. The Gram stain shows Gram-positive diplococci. Culture on blood agar shows alpha-hemolytic colonies that are bile soluble and optochin-sensitive. The MOST likely organism is:

NO.26 A patient with a history of solid organ transplantation develops a severe respiratory illness. Bronchoalveolar lavage fluid is positive for cytomegalovirus (CMV) DNA by PCR, and cytological examination reveals characteristic “owl’s eye” inclusions in enlarged cells. The MOST appropriate management strategy for this patient would include:

NO.27 A patient develops a febrile illness with jaundice and dark urine after receiving a blood transfusion.
Laboratory testing reveals an elevated level of unconjugated bilirubin and a positive direct Coombs test.
Serological testing is positive for antibodies against a protozoan parasite that infects erythrocytes. The MOST likely causative agent is:

NO.28 A microbiology laboratory receives a wound swab from a patient with a chronic, non-healing ulcer. Culture yields a Gram-positive, branching filamentous bacterium that is partially acid-fast. The MOST likely genus is:

NO.29 A patient develops a severe diarrheal illness after consuming raw seafood. Stool culture yields a Gram- negative, comma-shaped bacterium that is oxidase-positive and grows on thiosulfate-citrate-bile salts-sucrose (TCBS) agar, producing blue-green colonies. The MOST significant virulence factor contributing to the severe, cholera-like diarrhea caused by this organism is:

NO.30 A patient presents with a chronic, non-healing skin ulcer in a tropical region. Microscopic examination of a biopsy reveals amastigotes within macrophages. Culture of the biopsy on Novy-MacNeal-Nicolle (NNN) medium yields flagellated promastigotes. The MOST likely diagnosis is cutaneous leishmaniasis caused by:

NO.31 A clinical microbiology laboratory is monitoring the emergence of antimicrobial resistance. The detection of a bacterial isolate with reduced susceptibility to multiple classes of antibiotics, often due to horizontal gene transfer of resistance determinants, is characteristic of:

NO.32 A microbiology laboratory is investigating a possible outbreak of Salmonella infection. Serological testing of patient isolates reveals they all possess the same O antigen but different H antigens. This suggests:

NO.33 A clinical microbiology laboratory is evaluating a new multiplex PCR assay for the detection of respiratory viruses. To assess the assay’s specificity, they test a panel of samples known to contain various bacterial pathogens. A positive result is obtained for rhinovirus in a sample containing only Streptococcus pneumoniae.
This indicates:

NO.34 A microbiology laboratory is processing a stool sample for ova and parasites. A large (approximately 100
µm), thick-shelled, oval egg with a flattened side is observed. This egg MOST likely belongs to:

NO.35 A patient develops a severe skin infection after a puncture wound sustained while gardening. Culture of the wound exudate grows a Gram-positive, spore-forming bacillus that is anaerobic and produces a potent neurotoxin causing sustained muscle contraction. The MOST likely organism is: