A patient with a history of antibiotic use presents with diarrhea. Upon endoscopy, a pseudomembrane or plaque was observed. The most likely associated organism is:

Which of the following is bound on the cytoplasmic membrane of Staphylococcus aureus which has a high affinity for the Fc receptor on IgG molecules as well as complement?

Abiotrophia spp. (formally known as nutritionally variant streptococci) will not grow on blood or chocolate agars unless supplied with:

Which of the following statements is incorrect?

A gram-positive coccus that is catalase positive, lysostaphin susceptible, and modified oxidase negative is best identified as a member of the genus

An infant was brought to the emergency room appearing limp and “floppy”. The mother stated that she has just started to introduce table foods to her baby’s diet. A few days prior, she noted her baby to be constipated and to have diminished suckling and crying. This condition was most likely caused by:

The etiologic agent most commonly associated with septicemia and meningitis of newborns is:

The etiologic agent of erysipelas is:

The production of H2S is one characteristic used to differentiate which of the aerobic gram-positive bacilli?

Which one of the following is not appropriate when describing Mycoplasma hominis?

What compound is only found in Gram-positive bacteria?

Which of the following stains the metachromatic granules of Corynebacterium diphtheriae?

Which Shigella species ferments mannitol and is ONPG and orntihine decarboxylase positive?

Which of the following statements regarding Yersinia enterocolitica is incorrect?

Yersinia pestis and Yersinia enterocolitica are both:

Which of the following differentiates Proteus vulgaris from Proteus mirabilis?

I. Indole

II. H2S on TSI

III. Phenylalanine deaminase test

IV. Methyl Red

A positive Simmons citrate test is seen as a

Steam autoclave's setting includes:

Which of the following is not a characteristic of this bacterium which is associated mainly with UTIs predominantly in female adolescents and young women?

Alpha-hemolysis is seen on blood agar plate as

An organism produces a double hemolysis on egg yolk agar. This is due to what toxin

Obligate intracellular organisms:

I. Chlamydia

II. Mycoplasma

III. Rickettsia

IV. Viruses

A patient presents with hematuria and hypertension as a case of PSGN. Which of the following tests is used to document prior impetigo?

Which of the manifestations is part of the clinical picture of the tertiary stage of syphilis?

All of the following bacteria have capsules EXCEPT:

Thayer-Martin agar contains the following antibiotics, EXCEPT:

Which of the following is used as a prophylactic treatment to prevent gonococcal (Neisseria gonorrhoeae) conjunctivitis in newborns?

BCYE medium is used to isolate

On what phase of the bacterial growth curve does beta-Lactam antibiotics act on?

Psittacosis is a lower respiratory infection in humans caused by contact with what animal?

Class III biologic safety hood provides the highest level of personal protection. It is the most common in microbiology laboratories.

Which biosafety cabinet is being described? 30% Recirculated through HEPA, 70% exhausted

Which of the following species of Bacillus is nonmotile?

Which of the following correctly describes Escherichia coli O157:H7 on MacConkey-sorbitol agar?

Ethylhydrocupreine HCl susceptibility is a presumptive test for the identification of:

A beta-hemolytic, catalase and esculin hydrolysis-positive, gram-positive bacteria was isolated. Growth was also observed in 6.5% NaCl. This is most likely:

Fecal cultures are inoculated on thiosulfate-citrate-bile salts-sucrose agar specifically for the isolation of:

Neisseria lactamica closely resembles Neisseria meningitidis but can be differentiated from it by its ability to metabolize:

An oxidase-negative, gram-negative bacillus that produces an alkaline slant and acid butt on triple sugar iron (TSI) agar is able to ferment which of the following carbohydrates?

Which of the following nonphotochromogen slow grower Mycobacteria species will be ruled out if niacin is negative?

All of the following are rapidly growing mycobacteria, EXCEPT:

Which of the following antibiotics is affected, mostly seen with P. aeruginosa, by concentration of cations in the environment?

Which of the following test results is most helpful in categorizing an isolate as a member of the Tribe Proteae?

Which of the following exhibits a gliding motility?

What is the appearance of the colonies of Shigella spp. in XLD agar?

An organism that can live and grow in reduced concentrations of oxygen but prefers an anaerobic environment is known as a/an:

Which of the following produces a toxin similar to Shiga toxin produced by Shigella dysenteriae

Which of the following correctly describes the violet pigment, violacein produced by Chromobacterium violaceum?

I. Ethanol-soluble

II. Ethanol-insoluble

III. Water-soluble

IV. Water-insoluble

What step in the Gram stain distinguishes between gram-positive and gram-negative organisms?