Microbiology Test 5

Which 2 diseases are usually preceded by infection with the organism seen in the image below?

A common cause of acute exudative pharyngitis is:

A 15-year-old is admitted to the ER with severe sinusitis. Aspiration specimens from the nasal passage reveal a pure culture of alpha-hemolytic, depressed center colonies with a distinctive mucoid appearance on a blood agar plate. Gram stains of the colonies are shown below:

Which of the following could aid in the identification of the organism recovered?

A 6-year-old male presents to his pediatrician with a severe case of tonsillitis. The physician collects a throat swab specimen and orders a GAS (group A Streptococcus) probe test. The following day, the probe comes back negative. A culture is requested. The laboratory results are shown in this table:

Which of the following organisms is most likely causing the tonsillitis?

Small, pleomorphic gram-negative bacilli are isolated from an eye culture. They grow only on chocolate agar and are oxidase-variable. The most likely organism is:

An isolate on chocolate agar from a patient with epiglottitis is suggestive of Haemophilus species. Additional testing shows that the isolate required NAD for growth and is nonhemolytic. The organism is most likely Haemophilus:

A 3-year-old unimmunized female presents to the ER with a severe cough, fever, and flu-like symptoms. The parents report that the child had vomited a few times due to the severe coughing. A nasopharyngeal swab is used to collect the specimen and planted on a chocolate, Bordet-Gengou, and Regan Lowe media. After 5 days of incubation, colonies grow on all of the media, with the growth on Bordet-Gengou described as “drops of mercury. “The Gram stain shows minute coccobacilli that are catalase-positive and oxidase-positive. The most likely identification of this isolate is:

A Gram stain performed on a sinus aspirate reveals gram-negative diplococci and PMNs. Oxidase testing is positive and carbohydrate degradation tests are inert. The organism most likely is:

Establishing the pathogenicity of a microorganism isolated from a child’s throat and identified as Corynebacterium diphtheriae would depend upon:

Chlamydia trachomatis infections have been implicated in:

A liquid fecal specimen from a 3-month-old infant is submitted for culture. The stool culture should detect Salmonella, Shigella and:

When performing a stool culture, a colony type typical of an enteric pathogen is subcultured on a blood agar plate. The resulting pure culture is screened with several tests to obtain the results shown in this table:

The serological typing is verified with new kit and controls. The best course of action would be to:

MacConkey media for screening suspected cases of hemorrhagic E. coli O157:H7must contain:

An isolate from a stool culture gives the growth characteristics and biochemical reactions shown in this table:

These screening reactions are consistent with which of these enteric pathogens?

Which of the following organisms can grow in the small bowel and cause diarrhea in children, traveler’s diarrhea, or a severe cholera-like syndrome through the production of enterotoxins?

Shigella species characteristically are:

Gram-negative bacilli have been isolated from feces, and the confirmed biochemical reactions fit those of Shigella. The organism does not agglutinate in Shigella antisera. What should be done next?

Biochemical reactions of an organism are consistent with Shigella. A suspension is tested in antiserum without resulting agglutination. However, after 15 minutes of boiling, agglutination occurs in group-D antisera. The Shigella species is:

An 8-year-old girl is admitted to the hospital with a 3-day history of fever, abdominal pain, diarrhea, and vomiting. A stool culture grows many lactose-negative colonies that yielded the laboratory results shown in this table:

The most probable identification of this organism is:

A fecal specimen, inoculated to xylose lysine deoxycholate (XLD) and Hektoen enteric (HE) produced colonies with black centers. Additional testing results are shown in this table:

The most probable identification is: