MicroBraids Flashcards
All of the following statement is correct except?
-typhoid fever is transmitted only by humans
-proteus mirabilis is indole negative
-rapid urease activity is characteristic of the genus proteus
citrobacter species possess both lactose permease and beta-galactosidase enzymes.
-citrobacter species possess both lactose permease and beta-galactosidase enzymes.
A 29-year-old patient with acquired immunodeficiency syndrome (AIDS) is suspected of having a Cryptococcus neoformans infection in the cerebrospinal fluid (CSF). A CSF specimen is collected and set up on cycloheximide agar. In addition, an India ink stain is set up. The India ink stain reveals encapsulated yeast; however, 3 weeks later, the cycloheximide agar is negative. Which one of the following statements explains this discrepancy?
The ingredients in the cycloheximide agar most likely inhibited the growth of the organism
A 35-year-old woman has been very tired, with a low-grade fever and chills. She has a nonproductive cough and runs
out of breath easily. Results of a chest radiograph show patchy infiltrates. A Gram stain of sputum revealed many
white blood cells but no bacteria. Empirical treatment for walking pneumonia was initiated. Which of the following
microbes is most likely the cause of this disease?
Chlamydia pneumoniae
A 36-year-old male patient has an abscess with a strain of Staphylococcus aureus that is β-lactamase positive. This indicates that the organism is resistant to which of the following antibiotics?
Penicillin G, ampicillin
A 37 year old woman with a history of urinary tract infections comes to the emergency room with burning on urination along with frequency and urgency. She says her urine smells like ammonia. The cause of her urinary tract infection is likely to be
Proteus mirabilis
A 47-year-old woman presents with a 3-month history of progressive cough, weight loss, and fever. Chest radiography shows bilateral cavitary disease suggestive of tuberculosis. Sputum culture grows an acid-fast bacillus that is a photochromogen (makes an orange pigment when exposed to light). The organism most likely is
mycobacterium kansasii
A gram stained smear of a sputum specimen showed gram positive branching rods. The technologist should
perform a modified acid fast stain
a blood culture was drawn from an adult with a fever of 101F. The following day the laboratory reported the presence of the gram positive cocci in cluster from blood agar. what is the presumptive identification of this report?
Staphylococcus aureus
A fisherman who cut himself on a fishing hook later develops a cutaneous disease at the inoculation site. The exudate is aspirated and set up on a routine AFB medium for culture. It is incubated at 37° C, but no growth is observed after 8 weeks; however, a slide of the exudate was AFB-positive. Which one of the following statements explains these findings?
The organism should have been incubated at 30° C
septate hyphae is microscopically observed using lactophenol cotton blue. Which organism can be ruled out as the cause of infection on the basis of this information
Mucor
A wound sample produces polymicrobial anaerobic growth including an isolate that appears to be gram positive spore-forming bacillus. a next logical step is:
report preliminary identification as bacteroides fragilis group.
All of the following are important infection control strategies in containing spread of MRSA in hospitals except
Routine antimicrobial prophylaxis for all patients hospitalized for more than 48 hours
All of the following organisms are rapidly growing mycobacteria except
Mycobacterium bovis
All of the following statements are true except?
the virulence of corynebacterium diphtheriae is attributed to its destructive endotoxin
all of the following statements related to VDRL test are true except?
inactivated treponema pallidum serves as the antigen
an acid-fast smear on a patient’s sputum is positive. the tuberculin test, however is negative. A more definitive diagnosis could be obtained by
a chest radiograph
An endocervical swab was collected from a 26-year-old woman with a purulent discharge. The Gram stain revealed the following:
- Many white blood cells (WBCs)
- Moderate gram-negative diplococci
- Moderate gram-negative coccobacilli
- Few yeast
Based on these things, what would be the next course of action?
Report the Gram stain, and follow up with culture.
an organism suspected of being yersinia pestis is recovered from a patient with sepsis. the isolate has bipolar staining and is catalase positive but is oxidase and urease negative and is non motile. at this point, what should be done?
send the isolate to the nearest public health laboratory for confirmation
An organism inoculated to a TSI tube gave the following reactions:
alkaline slant/acid butt, no H2S, no gas produced
shigella sp.
bacillus antharcis and bacillus cereus can best be differentiated by which tests?
motility and beta-hemolysis on a blood agar plate.
candida albicans
patienx>patient y> oatient z
concerning toxoplasma gondii, all of the following are true except
domestic cats are intermediate hosts
cryptosporidium spp. oocysts are best described in fecal specimen using the
modified acid fast stain
fungi are not classified in kingdom plant primarily because they:
are heterotrophs
Gram stain of a smear taken from the periodontal pockets of a 30-year-old man with poor dental hygiene showed sulfur granules containing gram-positive rods (short diphtheroids and some unbranched filaments). Colonies on blood agar resembled “molar teeth” in formation. The most likely organism is:
actinomyces israelii
in which one of the following phase of bacterial growth do some bacteria form endospores?
Stationary Phase
lancefield’s classification of streptococci is based on:
cell wall carbohydrate antigens
listeria monocytogenes show which of the following characteristics?
it can grow at refrigerator temperatures.
one of the following diagnostic procedures can be considered a STAT procedure. that procedure is:
a blood film for malaria
prior infection with GAS can be demonstrated in with acute rhematic fever by which of the following?
culture of a heart valve
regarding members of the enterobacteriaceae, which of the following is the most accurate?
all members of the family have endotoxin
The HACEK bacteria
- fastidious gram neg bacilli, normal flora oral cavity.
- associated with endogenous endocarditis
- are treated with beta-lactam antibiotics
all of the above