MicroBraids

Question 1

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.

Answer 1

-citrobacter species possess both lactose permease and beta-galactosidase enzymes.

Question 2

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?

Answer 2

The ingredients in the cycloheximide agar most likely inhibited the growth of the organism

Question 3

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?

Answer 3

Chlamydia pneumoniae

Question 4

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?

Answer 4

Penicillin G, ampicillin

Question 5

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

Answer 5

Proteus mirabilis

Question 6

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

Answer 6

mycobacterium kansasii

Question 7

A gram stained smear of a sputum specimen showed gram positive branching rods. The technologist should

Answer 7

perform a modified acid fast stain

Question 8

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?

Answer 8

Staphylococcus aureus

Question 9

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?

Answer 9

The organism should have been incubated at 30° C

Question 10

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

Answer 10

Mucor

Question 11

A wound sample produces polymicrobial anaerobic growth including an isolate that appears to be gram positive spore-forming bacillus. a next logical step is:

Answer 11

report preliminary identification as bacteroides fragilis group.

Question 12

All of the following are important infection control strategies in containing spread of MRSA in hospitals except

Answer 12

Routine antimicrobial prophylaxis for all patients hospitalized for more than 48 hours

Question 13

All of the following organisms are rapidly growing mycobacteria except

Answer 13

Mycobacterium bovis

Question 14

All of the following statements are true except?

Answer 14

the virulence of corynebacterium diphtheriae is attributed to its destructive endotoxin

Question 15

all of the following statements related to VDRL test are true except?

Answer 15

inactivated treponema pallidum serves as the antigen

Question 16

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

Answer 16

a chest radiograph

Question 17

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?

Answer 17

Report the Gram stain, and follow up with culture.

Question 18

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?

Answer 18

send the isolate to the nearest public health laboratory for confirmation

Question 19

An organism inoculated to a TSI tube gave the following reactions:

alkaline slant/acid butt, no H2S, no gas produced

Answer 19

shigella sp.

Question 20

bacillus antharcis and bacillus cereus can best be differentiated by which tests?

Answer 20

motility and beta-hemolysis on a blood agar plate.

Question 21

candida albicans

Answer 21

patienx>patient y> oatient z

Question 22

concerning toxoplasma gondii, all of the following are true except

Answer 22

domestic cats are intermediate hosts

Question 23

cryptosporidium spp. oocysts are best described in fecal specimen using the

Answer 23

modified acid fast stain

Question 24

fungi are not classified in kingdom plant primarily because they:

Answer 24

are heterotrophs

Question 25

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:

Answer 25

actinomyces israelii

Question 26

in which one of the following phase of bacterial growth do some bacteria form endospores?

Answer 26

Stationary Phase

Question 27

lancefield's classification of streptococci is based on:

Answer 27

cell wall carbohydrate antigens

Question 28

listeria monocytogenes show which of the following characteristics?

Answer 28

it can grow at refrigerator temperatures.

Question 29

one of the following diagnostic procedures can be considered a STAT procedure. that procedure is:

Answer 29

a blood film for malaria

Question 30

prior infection with GAS can be demonstrated in with acute rhematic fever by which of the following?

Answer 30

culture of a heart valve

Question 31

regarding members of the enterobacteriaceae, which of the following is the most accurate?

Answer 31

all members of the family have endotoxin

Question 32

The HACEK bacteria - fastidious gram neg bacilli, normal flora oral cavity. - associated with endogenous endocarditis - are treated with beta-lactam antibiotics

Answer 32

all of the above

Question 33

The pneumococcus cause all of the following except | causes: pneumonia, otis media, sinustis, meningitis

Answer 33

Necrotizing fasciitis

Question 34

the agar recommended by the NCCLS for routine susceptibility testing

Answer 34

Mueller-Hinton Agar

Question 35

the main reason why methicillin- resistant staphlococcus aureus MRSA strains are resistant to methicillin is

Answer 35

they have altered penicillin binding proteins that have reduced binding of the antibiotics.

Question 36

the majority of clinical laboratory in the US with a microbiology department should have the capability of serotyping which is pathogenic enterobacteriaceae?

Answer 36

shinaga toxin-producing E coli, salmonella, shingella spp

Question 37

the wife of a 65 year man with COPD...pulmonary infection

Answer 37

Haemophilis Influenza

Question 38

140 colonies urine

Answer 38

1.4x10^5

Question 39

what is the common virulence factor for causes of meningitis by neisseria meningitis and haemophilus influenzae?

Answer 39

capsule

Question 40

what is the purpose of the optochin(p-disk) test?

Answer 40

distinguish among alpha-hemolytic streptococci

Question 41

when clinical specimens are being processed for the recovery of mycobacterium tuberculosis, the generally recommended method for digestion and decontamination of sputum samples is

Answer 41

N-acetyl-L-Cysteine-NaOH

Question 42

which of the following diagnostic methods is not performed on broncholveolar lavage specimen for a patient suspected for pneumocystsis pneumonia?

Answer 42

Culture

Question 43

which of the following etiologies of bacterial pharyngitis is not detected by routine aerobic throat culture?

Answer 43

Fusobacterium necrophorum

Question 44

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?

Answer 44

salmonella typhimurium

Question 45

which of the following is incorrect statement? | -the anaerobes most often involved in infectious disease are from endogenous source

Answer 45

????????

Question 46

which of the following is appropriate to determine the etiologic diagnosis of infectious disease?

Answer 46

?????

Question 47

which of the following is correct regarding blood film microscopy?

Answer 47

minimal technical labor is required

Question 48

which of the following is the description of cytopathic effects in viral culture?

Answer 48

the visual changes produced in an infected cell by a virus

Question 49

which of the following is the description of cytopathic effects in viral culture?

Answer 49

the visual changes produced in an infected cell by a virus

Question 50

which of the following specimens would be unacceptable for anaerobic urine?

Answer 50

urethral swab

Question 51

which of the following statements regarding interferon-gamma release assays is correct?

Answer 51

They are used as alternatives to the tuberculin skin test to evaluate for latent tuberculosis.

Question 52

which of the following is NOT true of haemophilus influenzae?

Answer 52

the organism can be readily cultured on sheep blood agar in an environment of elevated CO2

Question 53

which of the following statements best defines the minimum inhibitory concentration (MIC) OF A BACTERIAL PATHOGEN TO AN ANTIMICROBIAL agent?

Answer 53

the MIC is the lowest drug level that kills the bacterial pathogen

Question 54

which statement is incorrect for neisseria meningitidis?

Answer 54

part of the transient flora of the upper respiratory tract

Question 55

which statement regarding the laboratory identification of fungi is correct?

Answer 55

the identification of putative dimorphic fungi confirmed by conversion of mold to yeast or detection of species specific antigens or DNA sequence analysis.

Question 56

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?

Answer 56

gram positive cocci clusters catalase positive, coagulase-negative.

Question 57

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?

Answer 57

Obligate intracellular dimorphic bacterium

Question 58

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?

Answer 58

Bacillus anthracis

Question 59

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:

Answer 59

Inability to ferment lactose and sucrose

Question 60

the diagnostic method most commonly used for the identification of lyme disease is:

Answer 60

serology

Question 61

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

Answer 61

type 1 diabetes

Question 62

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

Answer 62

rheumatoid arthritis

Question 63

test for rheumatoid factor detects:

Answer 63

IgM directed against the Fc region of IgG

Question 64

which of the following would be used as a secondary antibody in an ELISA to detect antibodies to influenza A virus patient samples?

Answer 64

?????? A B or C

Question 65

which types of hepatitis are transmitted primarily through contact with blood or other body fluids?

Answer 65

Hepatitis B, C and D

Question 66

``` 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 ```

Answer 66

acute hepatitis B infection

Question 67

the probability that a person with a positive screening that actually has the disease screened for is called:

Answer 67

positive predictive value

Question 68

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?

Answer 68

Streptococcus pyogenes

Question 69

the vectors that transmit borrelia burgdorferi from natural reservoirs to humans are

Answer 69

ixodes species of ticks

Question 70

using the reverse algorithm method for syphilis diagnosis, a positive initial test and a negative follow-up test could be interpreted as:

Answer 70

past syphilis infection with subsequent decline in nontreponemal antibody titers

Question 71

which of the following EBV markers would be most likely positive for an individual who has infectious mononucleosis three years ago?

Answer 71

Anti-VCA (igG), anti-EA, and anti-EBNA

Question 72

A patient with infectious mononucleosis would have what outstanding feature in hematology evaluation?

Answer 72

presence of atypical lymphocytes

Question 73

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

Answer 73

infectious mononucleosis

Question 74

a FANA performed on a 20 year old woman with suspected SLE produced the result indicated below. this result us best described as:

Answer 74

??????

Question 75

the indirect immunofluorescent (IIF) test for antibodies which uses crithidia luciliae as a substrate:

Answer 75

is specific for SLE when antibody titers are high

Question 76

the clinical hallmark of early lyme disease infection is

Answer 76

erythema migrans

Question 77

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

Answer 77

acute glomerulonephritis

Question 78

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.

Answer 78

secondary syphilis

Question 79

a patient is suspected of having latent syphilis. which set of test results for RPR, TP-PA, and CSF-VDRL best confirms this diagnosis?

Answer 79

RPR = nonreactive; TP-PA = reactive; VDRL = nonreactive

Question 80

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?

Answer 80

positive test for either igG or igM rubella antibodies