Microbiology and Parasitology Samplex Test 2

A truck driver was involved in a serious accident and received second and third degree burns over his body. He was placed in the burn unit and on his twelfth hospital day, he suddenly developed a wound infection with a bluish green exudate. Treatment with chloramphenicol and tetracycline was unsuccessful. A gram negative, motile organism was isolated that was oxidase positive, did not ferment lactose, sucrose or glucose but grew on MacConkey’s agar and produced a fruity aroma on that medium. Which of the following organisms was most likely isolated?

A group of 25 fifth grade students had lunch at a fast food restaurant. Most ate hamburgers and French fries prepared quickly for the noontime rush. The next day most of the children experienced severe bloody diarrhea and nausea with several requiring hospitalization. Stool and blood cultures recovered a small, gram-negative, non-mucoid bacilli which fermented lactose, were indole positive, produced acid and carbon dioxide but produced neither hydrogen sulfide nor urease. The organism most likely responsible for the intestinal infection is:

A 4 year old boy presents to the pediatric emergency department with the classic meningitis triad of fever, headace and nuchal rigidity. A lumbar puncture is performed and analysis of fluid shows an increase in polymorphonuclear cells, an increased protein level, and a decreased glucose level. Which of the following is the most comon cause of mengitis in a child of this age with this clinical picture?

A 50 year old man develops non-bloody watery diarrhea while working as an aid worker in a refuge camp in Cambodia. He arrived in the area 3 days ago. A stool smear shows no WBCs but revealed a gram negative curved bacilli, which is oxidase positive. He subsequently develops dehydration and electrolyte abnormalities leading to cardiac and renal failure. Which of the following organism is the most likely cause of this man’s enterocolitis?

A 31 year old pregnant woman comes to her attending physician because of painful vesicular lesions that have recently appeared in her genitalia. A positive result on which of the following diagnostic tests would mean that her baby is at risk for congenital anomalies?

What is the drug of choice for Trichuris trichuria infection?

A 24 year old call center agent was diagnosed to have AIDS.One week after, he experienced persistent watery diarrhea secondary to a bacterial etiology. Which of the following is the most likely subtype of E. coli?

A 3 year old female came in due to persistent cough for more than 2 weeks, anorexia and night sweats. Sputum exam was consistent with PTB. In primary complex, evidence of radiographically detectable calcification of a subpleural granuloma and its associated lymp node is called?

A psychotic indigent man with a history of multi- substance abuse has been involuntarily hospitalized for 1 week because of persistent diarrhea. Stool sample was sent for ova and parasites, revealing numerous granular, spherical, thin walled cyst measuring 10-20 um diameter. Trichrome stains show up to four nuclei in most of the cysts. these findings are consistent with an infection by which of the following organisms?

An 8-month-old, previously healthy, came into your clinic for high grade fever for 3 days duration. Further history revealed that on the 4th day, after the fever was resolved, a rose-red macular rashes 2-6 mm in diameter on her trunk and proximal extremities appeared. What is the most likely etiologic agent in this case.

A 14-year-old patient is brought in by his parents because of sore throat. On P.E., he is febrile and has a pharyngeal erythema with a tonsillar abscess. A throat culture on sheep blood agar yields colonies of gram-positive cocci that are surrounded by a zone of complete hemolysis. The organism was also plated on mannitol salt agar; it grew well and caused the medium to turn gold. Which of the following microorganisms is the most likely cause of the patient’s illness?

A 6-year-old female came to your clinic due to high grade fever, sore throat and odynophagia. Tender vesicles in her oropharynx were noted. The diagnosis of herpangina was made. What is the most likely etiology?

The blood culture of a patient with a presumptive diagnosis of endocarditis yields a non-hemolytic colonies of gram positive cocci. The isolate was catalase negative and was noted that it grew in 6.5 % Na Cl and was resistant to penicillin. The isolate is most likely?

A patient with AIDS presents with headaches of increasing severity and mental lethargy. On P.E, macronodular skin lesions are noted. The CSF is clear, and protein and glucose concentrations are within normal levels. On India ink wet mount, encapsulated yeasts can be seen. Which of the following methods will permit rapid confirmation of the identity of the infective organism?

Which of the following diseases is caused by a virus that uses a reverse transcriptase during replication?

An alcoholic presents complaining of chest pain, fever, shaking chills, cough and myalgia. He was very cold 2 nights ago and says he felt “poorly” ever since. Her cough is producing rust-colored, odorless, mucoid sputum. His temperature on admission is 40 C. His WBC count is 16,000 cells/mm3 with PMN predominance with an overall left shift. An alpha hemolytic, lancet-shaped, gram-positive diplococcus is isolated on blood agar. What is the most likely causative agent?

Pieces of plasmid or bacterial chromosomal DNA may be mistakenly packaged into the capsid of a bacterial virus. Assuming that no prophage state has existed in the phage production, what is the process called when virus with bacterial or plasmid DNA infects another bacterium?

A patient with sickle cell anemia is most likely to have repeated septicemias with?

A compromised patient is admitted due to respiratory distress. She had signs of focal central nervous system lesions early in the day and is now on the comatose state. The CNS and pulmonary biopsies show dichotomously branching septate hyphae. What is the most likely underlying condition?

A 16-year-old female from a dormitory presents with sudden onset of fever of 40 C, severe headache and generalized petechial rash. Physical examination reveals nuchal rigidity. CSF culture was done revealing an organism which ferments both maltose and glucose with large polysaccharide capsule. Which one of the following is the MOST likely predisposing factor to your diagnosis in this case?