Kategorie American Society of Microbiology

NR. 116 A research laboratory is studying the pathogenesis of respiratory syncytial virus (RSV) infection in infants.
They find that a specific viral surface glycoprotein is primarily responsible for attachment to host cells. This glycoprotein is:

NR. 117 A clinical microbiology laboratory is monitoring the emergence of resistance to colistin in Gram-negative bacteria. Resistance to colistin is often mediated by modifications of the bacterial lipopolysaccharide (LPS).
The genetic basis for acquired colistin resistance most commonly involves:

NR. 118 A patient with HIV infection and a CD4+ T-cell count below 50 cells/µL develops a progressive neurological illness characterized by confusion, motor deficits, and seizures. Brain MRI reveals multiple white matter lesions without mass effect. PCR of the CSF is positive for JC virus. Thepathogenesis of this condition, progressive multifocal leukoencephalopathy (PML), involves:

NO.119 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:

NR. 120 A patient with a history of neutropenia following chemotherapy develops a rapidly progressive pneumonia.
Bronchoalveolar lavage fluid reveals septate hyphae with acute angle (45-degree) branching. The MOST likely diagnosis is invasive pulmonary aspergillosis caused by:

NO.121 A 30-year-old female who recently returned from a hiking trip in the northeastern United States presents to her physician with a two-week history of a slowly expanding, erythematous rash with central clearing on her thigh. She also reports intermittent fatigue, arthralgias, and mild headache. Serological testing reveals a positive IgM and IgG response to Borrelia burgdorferi. Which of the following mechanisms is MOST significant in the pathogenesis of the clinical manifestations observed in this patient?

NR. 122 A patient with a history of liver transplantation develops a bloodstream infection with a Gram-negative bacterium. The isolate is identified as Sphingomonas paucimobilis. This opportunistic pathogen is known for its ability to:

NR. 123 Transmissible spongiform encephalopathies (TSEs), such as Creutzfeldt-Jakob disease (CJD) in humans and Bovine Spongiform Encephalopathy (BSE) in cattle, are caused by infectious agents composed primarily of:

NR. 124 A clinical microbiology laboratory is using flow cytometry to analyze lymphocyte subsets in a patient with suspected immunodeficiency. Which of the following cell surface markers is typically used to identify helper T cells?

NR. 125 A clinical microbiology laboratory is using PCR to detect the presence of the mecA gene in Staphylococcus aureus isolates. The mecA gene encodes for:

NR. 126 Which of the following bacterial genera inherently possesses D-alanyl-D-lactate peptide subunits in its peptidoglycan precursors, conferring natural, high-level resistance to vancomycin?

NR. 127 A patient develops a severe gastrointestinal illness after consuming undercooked poultry. Stool culture yields a Gram-negative, microaerophilic, curved bacillus that is oxidase-positive. The MOST likely organism is:

NR. 128 A clinical microbiology laboratory is using isothermal nucleic acid amplification techniques for rapid detection of Mycobacterium tuberculosis in sputum. Compared to conventional PCR, isothermal methods offer the advantage of:

NR. 129 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:

NR. 130 A clinical microbiology laboratory is performing quality control on antimicrobial susceptibility testing. The zone diameter for Escherichia coli ATCC 25922 tested against ciprofloxacin is consistently smaller than the acceptable range published by CLSI. The MOST likely cause of this discrepancy is:

NR. 131 An elderly patient in a long-term care facility develops a localized outbreak of painful vesicles along a dermatome. Tzanck smear of a vesicle reveals multinucleated giant cells. The MOST likelycausative agent is: