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
The pneumococcus cause all of the following except
causes: pneumonia, otis media, sinustis, meningitis
Necrotizing fasciitis
the agar recommended by the NCCLS for routine susceptibility testing
Mueller-Hinton Agar
the main reason why methicillin- resistant staphlococcus aureus MRSA strains are resistant to methicillin is
they have altered penicillin binding proteins that have reduced binding of the antibiotics.
the majority of clinical laboratory in the US with a microbiology department should have the capability of serotyping which is pathogenic enterobacteriaceae?
shinaga toxin-producing E coli, salmonella, shingella spp
the wife of a 65 year man with COPD…pulmonary infection
Haemophilis Influenza
140 colonies urine
1.4x10^5
what is the common virulence factor for causes of meningitis by neisseria meningitis and haemophilus influenzae?
capsule
what is the purpose of the optochin(p-disk) test?
distinguish among alpha-hemolytic streptococci
when clinical specimens are being processed for the recovery of mycobacterium tuberculosis, the generally recommended method for digestion and decontamination of sputum samples is
N-acetyl-L-Cysteine-NaOH
which of the following diagnostic methods is not performed on broncholveolar lavage specimen for a patient suspected for pneumocystsis pneumonia?
Culture
which of the following etiologies of bacterial pharyngitis is not detected by routine aerobic throat culture?
Fusobacterium necrophorum
which of the following gram-negative, oxidase-negative bacilli isolated from the stool of a person with diarrhea would yield a colorless colony on macconkey agar?
salmonella typhimurium
which of the following is incorrect statement?
-the anaerobes most often involved in infectious disease are from endogenous source
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which of the following is appropriate to determine the etiologic diagnosis of infectious disease?
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which of the following is correct regarding blood film microscopy?
minimal technical labor is required
which of the following is the description of cytopathic effects in viral culture?
the visual changes produced in an infected cell by a virus
which of the following is the description of cytopathic effects in viral culture?
the visual changes produced in an infected cell by a virus
which of the following specimens would be unacceptable for anaerobic urine?
urethral swab
which of the following statements regarding interferon-gamma release assays is correct?
They are used as alternatives to the tuberculin skin test to evaluate for latent tuberculosis.
which of the following is NOT true of haemophilus influenzae?
the organism can be readily cultured on sheep blood agar in an environment of elevated CO2
which of the following statements best defines the minimum inhibitory concentration (MIC) OF A BACTERIAL PATHOGEN TO AN ANTIMICROBIAL agent?
the MIC is the lowest drug level that kills the bacterial pathogen
which statement is incorrect for neisseria meningitidis?
part of the transient flora of the upper respiratory tract
which statement regarding the laboratory identification of fungi is correct?
the identification of putative dimorphic fungi confirmed by conversion of mold to yeast or detection of species specific antigens or DNA sequence analysis.
you are in the clinical laboratory looking at a gram stain when the laboratory technician comes up to you and says “i think your patient has staphylococcus epidermidis bacteremia” which of the following results did technicians find with the organism recovered from culture?
gram positive cocci clusters catalase positive, coagulase-negative.
33-year-old man had urethritis, difficulty urinating, and a greenish-yellow discharge. Isolation of Neisseria gonorrhoeae on Thayer-Martin medium prompted treatment with ceftriaxone, but he continued to have a watery discharge that contained white blood cells. The treatment should also have covered which of the following agents?
Obligate intracellular dimorphic bacterium
A 45-year-old cattle rancher presents to his physician with a wound on his forearm that resembles a large scab. Samples collected from the wound were cultured and examined. The bacteria recovered were Gram positive, nonmotile rods with square ends. The cultured bacteria formed irregularly shaped, nonhemolytic colonies on blood agar plates and individual
cells from the plates had a centrally located spore. What is the most likely cause of this infection?
Bacillus anthracis
An 18-year-old student has abdominal cramps and diarrhea. A plate of MacConkey’s agar is inoculated and grows gram-negative rods. TSI agar is used to screen the isolates for salmonellae and shigellae. A result suggesting one of these two pathogens would be:
Inability to ferment lactose and sucrose
the diagnostic method most commonly used for the identification of lyme disease is:
serology
A 10-year-old girl was brought in to her physician’s office because she had been complaining that she was thirsty and had to go to the bathroom all the time. She had lost 15 pounds over the last 6 months and was more irritable than usual, especially after meals. The girl’s fasting blood glucose was 575 mg/dL, her C-peptide was 0.5 ng/mL, and she had autoantibodies against glutamic acid decarboxylase and insulin. This girl has
type 1 diabetes
an autoimmune disease characterized by pain and progressive destruction of the joints, weight loss, morning stiffness and the presence of an antibody directed against igG best describes
rheumatoid arthritis
test for rheumatoid factor detects:
IgM directed against the Fc region of IgG
which of the following would be used as a secondary antibody in an ELISA to detect antibodies to influenza A virus patient samples?
?????? A B or C
which types of hepatitis are transmitted primarily through contact with blood or other body fluids?
Hepatitis B, C and D
the following laboratory results are from a patient with hepatomegaly and jaundice liver enzymes elevated igM anti-HAV negative HBsAg Positive IgM anti-HBc positive anti-HCV negative theses are indicative of
acute hepatitis B infection
the probability that a person with a positive screening that actually has the disease screened for is called:
positive predictive value
which microorganism is capable of causing life threating situations in which superantigens activate abnormally large numbers of T cells to release massive amounts of cytokines?
Streptococcus pyogenes
the vectors that transmit borrelia burgdorferi from natural reservoirs to humans are
ixodes species of ticks
using the reverse algorithm method for syphilis diagnosis, a positive initial test and a negative follow-up test could be interpreted as:
past syphilis infection with subsequent decline in nontreponemal antibody titers
which of the following EBV markers would be most likely positive for an individual who has infectious mononucleosis three years ago?
Anti-VCA (igG), anti-EA, and anti-EBNA
A patient with infectious mononucleosis would have what outstanding feature in hematology evaluation?
presence of atypical lymphocytes
several college freshmen present to the student health service complaining of sore throat fatigue and fever for the past week. the monospot test is performed and reported as positive for the students. the most likely cause of symptom is
infectious mononucleosis
a FANA performed on a 20 year old woman with suspected SLE produced the result indicated below. this result us best described as:
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the indirect immunofluorescent (IIF) test for antibodies which uses crithidia luciliae as a substrate:
is specific for SLE when antibody titers are high
the clinical hallmark of early lyme disease infection is
erythema migrans
a 9 year old boy is brought to an emergency room with a history of fever, blood in urine, and puffiness around the eyes laboratory test showed erythrocytes and granular casts in urine reduced glomerular filtration rate, and an elevated antistreptolysin O titer 650. throat cultures yielded streptococcus pyogen sand staphylococcus aureus. the most likely diagnosis
acute glomerulonephritis
a 25 year old patient presents with fine rashi on his chest, palms, and feet; fever, and malaise. the RPR is reactive with a titer of 1;64, the VDRL is non reactive, and the TP-PA is positive.
secondary syphilis
a patient is suspected of having latent syphilis. which set of test results for RPR, TP-PA, and CSF-VDRL best confirms this diagnosis?
RPR = nonreactive; TP-PA = reactive; VDRL = nonreactive
Mrs RK is suspected of having contracted rubella in the last trimester of her pregnancy. which of the following would confirm the diagnosis of congenital rubella syndrome in the infant at birth?
positive test for either igG or igM rubella antibodies
