Micro Lab 13 PowerPoint Questions Spring 2026

The most common source of hospital acquired infections that is responsible 70-80% of complicated UTI’s is caused by which medical device?

 

urinary catheters

 

surgical scalpels

 

stents

 

hypodermic needles

 

urinary catheters

Which enteric bacteria causes 70-95% of uncomplicated UTIs?

 

UPEC

 

Proteus mirabilis

 

Pseudomonas aeruginosa

 

Klebsiella pneumoniae

UPEC

Which bacteria is the most common cause of Gram-positive uncomplicated UTIs?

 

Staphylococcus aureus

 

Staphylococcus saprophyticus

 

Enterococcus faecalis

 

Group B streptococcus

Staphylococcus saprophyticus

Which fungal genus and species is the most common cause fungal UTIs?

 

Cryptosporidium sp.

 

Tinea corporis

 

Candida albicans

 

Tinea pedis

 

Candida albicans

The etiological agent of genital herpes is _______________.

 

HSV-2

 

cytomegalovirus

 

Staphylococcus aureus

 

varicella-zoster

HSV-2

What is the most dangerous form of neonatal herpes?

 

central nervous system effects

 

disseminated infection

 

skin, eyes, and mouth (SEM) manifestations

 

disseminated infection

What infection exhibits ulcers that are referred to as "dewdrops on rose petals", describing the look of the clear pustule above a reddened base?

 

genital herpes

 

genital warts

 

lymphogranuloma venereum

 

chancroid

genital herpes

The most common STI in the world that causes genital warts and cervical cancer is caused by ______________.

 

cytomegalovirus

 

HIV

 

HSV-2

 

HPV

 

HPV

What percentage of cervical cancers are caused by HPV?

 

90%

 

65%

 

50%

 

100%

 

90%

What test is a cheap, easy, and noninvasive method for detecting HPV infections as well as precancerous and cancerous cervical cells?

 

tourniquet test

 

direct ELISA

 

PCR

 

PAP smear

 

PAP smear

Identify the manifestation of HPV in this image.

 

ulcer

 

chancre

 

anal warts

 

genital warts

genital warts

True or False? Vaginitis is diagnosed by Amsel’s criteria.

 

True

 

False

False

Which bacterium has two main biovars called trachoma and lymphogranuloma venereum?

 

Chlamydia trachomatis

 

Treponema pallidum

 

Trichomonas vaginalis

 

Leptospira interrogans

 

Chlamydia trachomatis

Which biovar of Chlamydia trachomatis causes primary stage, painless ulcers?

 

UPEC

 

lymphogranuloma venereum

 

trachoma

 

all answers are correct

 

lymphogranuloma venereum

What infection is many times asymptomatic, but in certain cases cause men to have dysuria and a whitish urethral discharge?

 

gonorrhea

 

lymphogranuloma venereum

 

syphilis

 

chancroid

gonorrhea

Which bacterium is the etiological agent of PID and ophthalmia neonatorum?

 

Neisseria gonorrhoeae

 

Haemophilus ducreyi

 

Leptospira interrogans

 

Proteus mirabilis

 

Neisseria gonorrhoeae

Which bacterium is the etiological agent of syphilis?

 

Treponema pallidum

 

Chlamydia trachomatis

 

Proteus mirabilis

 

Leptospira interrogans

 

Treponema pallidum

Which stage of syphilis is characterized by a chancre appearing at the initial infection site, where the spirochete invades the new host’s tissues and begins to multiply?

 

secondary stage

 

quaternary stage

 

tertiary stage

 

primary stage

primary stage

Which stage of syphilis usually involves a disseminated rash, which may appear on the skin or on mucous membranes in the mouth, vagina, or anus?

 

secondary syphilis

 

quaternary syphilis

 

tertiary syphilis

 

primary syphilis

 

secondary syphilis

Which stage of syphilis can be fatal? This stage causes lesions on the skin and bones, heart damage, and neurological symptoms.

 

quaternary syphilis

 

tertiary syphilis

 

secondary syphilis

 

primary syphilis

 

tertiary syphilis

Painful genital ulcers caused by Haemophilus ducreyi are called __________.

 

genital warts

 

disseminated ulcers

 

pustules

 

chancres

chancres

Which infections displays painful lesions called chancres?

 

gonorrhea

 

secondary syphilis

 

lymphogranuloma venereum

 

chancroid

chancroid

Infection with which bacterium is one of the most important cofactors in the transmission of HIV?

 

Haemophilus ducreyi

 

UPEC

 

Proteus mirabilis

 

Pseudomonas aeruginosa

 

Haemophilus ducreyi

Candida albicans is part of normal vaginal microbiota, but it can cause infections if the normal microbiota is changed. Which of the following is a reason for changes in the vaginal microbiota that can result in vulvovaginal candidiasis?

 

antibiotic therapy

 

all of the answers are correct

 

increased estrogen

 

increased vaginal pH

all of the answers are correct

What is the common name of vulvovaginitis candidiasis?

 

leptospirosis

 

ringworm

 

Baker’s infection

 

yeast infection

 

yeast infection

Which vaginal infection is characterized by a “cottage cheese” discharge?

 

vulvovaginal candidiasis

 

trichomoniasis

 

vaginosis

 

gonorrhea

 

vulvovaginal candidiasis

What fungal vaginal infection is characterized by this type of discharge?

 

gonorrhea

 

trichomoniasis

 

chancroid

 

vulvovaginal candidiasis

vulvovaginal candidiasis

What type of microbe causes trichomoniasis?

 

bacteria

 

virus

 

fungi

 

protist parasite

 

protist parasite

Diagnosis of which infection is done by performing a wet mount observation of vaginal discharge?

 

vulvovaginal candidiasis

 

trichomoniasis

 

chancroid

 

chlamydia

trichomoniasis

Which of the following is a way that and individual could contract an STD?

 

all answers stated are ways that someone could contract an STD

 

having multiple sex partners

 

having sexual intercourse without using a condom

 

sharing needles for tattoos or piercings

all answers stated are ways that someone could contract an STD

Herpes is caused by the viruses, HSV-1 and HSV-2. HSV-1 usually causes ________ herpes, while HSV-2 usually causes _________ herpes.

 

oral; genital

 

fallopian; epidydimal

 

cervical; esophageal

 

urethral; cervical

 

oral; genital

Which of the following microbes that cause reproductive diseases can typically be prevented by a vaccination that is administered to individuals who are 26 and under, and who don’t have the disease?

 

HSV-2

 

HIV

 

HPV

 

HSV-1

HPV

An infection with Chlamydia is easily spread, because ________.

 

it is a chronic disease

 

the bacterial has a capsule to avoid phagocytosis

 

the virus has a long latent period

 

it is usually asymptomatic

it is usually asymptomatic

The tertiary stage of syphilis can affect what part of the body?

 

nerves

 

heart

 

brain

 

all the stated body parts can be affected by tertiary syphilis

all the stated body parts can be affected by tertiary syphilis

__________ drug resistance occurs as a result of genetic mutations or gaining resistance genes via horizontal gene transfer.

 

Acquired

 

Intrinsic

 

Unnatural

 

Natural

Acquired

Another name for the disk diffusion agar test or antimicrobial susceptibility test is the ___________.

 

AMES test

 

Voges-Proskauer test

 

Kirby-Bauer test

 

drug resistance test

Kirby-Bauer test

The clear area surrounding an antibiotic-infused filter paper disk is called ___________.

 

zone of inhibition

 

plaque

 

inhibition area

 

bacterial-free zone

zone of inhibition

The type of agar used for the antimicrobial susceptibility test is ___________.

 

Thayer-Martin agar

 

Mueller-Hinton

 

TSA

 

Lowenstein-Jensen agar

Mueller-Hinton

When performing an antimicrobial susceptibility test, why is it necessary to swab the agar four times in different directions?

 

the inoculation technique allows for isolated colonies to grow

 

the inoculation technique ensures complete microbial growth across the plate

 

the inoculation technique results in four distinct streaks where four separate antimicrobial drugs can be tested

 

without swabbing the plate several times, microbial growth is unlikely

the inoculation technique ensures complete microbial growth across the plate

To determine a test microbe’s drug susceptibility, which measurement should be compared with the CLSI table values?

 

the area of the zone of inhibition

 

the circumference of the zone of inhibition

 

the radius of the zone of inhibition

 

the diameter of the zone of inhibition

the diameter of the zone of inhibition

You perform an antimicrobial susceptibility test on Pseudomonas aeruginosa, a multidrug-resistant Gram-negative bacterium. The zone diameter measurements for the drugs ampicillin and polymyxin are both 13mm. Given the zone diameter measurements, what is the susceptibility of P. aeruginosa to ampicillin (AMP) and polymyxin (PM)?

CLSI Values for PM: resistant ≤11mm, intermediate none, susceptible ≥12mm

CLSI Values for AMP: resistant ≤13mm, intermediate 14-16mm, susceptible ≥17mm

 

the bacterium is resistant to both polymyxin and ampicillin

 

the bacterium is susceptible to polymyxin and resistant to ampicillin

 

the bacterium is susceptible to both polymyxin and ampicillin

 

the bacterium is resistant to polymyxin and susceptible to ampicillin

the bacterium is susceptible to polymyxin and resistant to ampicillin

You are swabbing an agar plate for antimicrobial susceptibility testing. What step should occur immediately after uncapping the broth culture tube?

 

uncap the agar plate

 

dip the sterile cotton swab into the broth

 

drag the cotton swab alongside the wall of the tube

 

flame sterilize the tube lip

flame sterilize the tube lip

You are preparing an agar plate to perform an antimicrobial susceptibility test. How should you first inoculate your plate?

 

swab in a random zig-zag pattern

 

swab side-to-side in one quadrant of the plate

 

swab back-and-forth and top-to-bottom in a tight pattern over the entire agar surface

 

swab to isolate colonies

swab back-and-forth and top-to-bottom in a tight pattern over the entire agar surface

You are performing an antimicrobial susceptibility test. What step should occur immediately after placing the antimicrobial drug disk on the test plate?

 

dip forceps in ethanol

 

use forceps to pick up and securely place the next antimicrobial drug disk on the plate

 

flame-sterilize the forceps by passing them quickly through the Bunsen burner flame, burning off all alcohol in the process

 

gently tap the disk with forceps

 

gently tap the disk with forceps

These are the results of an Escherichia coli antimicrobial susceptibility test. Using the CLSI table, analyze the effect of ciprofloxacin (CIP) on E. coli.

 

resistant

 

susceptible

 

intermediate

 

intermediate

These are the results of an Escherichia coli antimicrobial susceptibility test. Using the CLSI table, analyze the effect of erythromycin (E) on E. coli.

 

intermediate

 

susceptible

 

resistant

resistant

These are the results of an Escherichia coli antimicrobial susceptibility test. Using the CLSI table, analyze the effect of chloramphenicol (C) on E. coli.

 

intermediate

 

resistant

 

susceptible

susceptible

These are the results of a Staphylococcus aureus antimicrobial susceptibility test. Using the CLSI table, analyze the effect of vancomycin (VA) on S. aureus.

 

susceptible

 

resistant

 

intermediate

resistant

These are the results of a Staphylococcus aureus antimicrobial susceptibility test. Using the CLSI table, analyze the effect of erythromycin (E) on S. aureus.

 

resistant

 

susceptible

 

intermediate

 

resistant

These are the results of a Staphylococcus aureus antimicrobial susceptibility test. Using the CLSI table, analyze the effect of ciprofloxacin (CIP) on S. aureus.

 

intermediate

 

susceptible

 

resistant

resistant

These are the results of an antimicrobial susceptibility test. Your lab partner reviews the zone measurement of each test drug and determines that chloramphenicol worked the best against the inoculated organism. How should you respond?

 

the inoculated organism is the most susceptible to vancomycin and ciprofloxacin given they have the largest relative zones

 

the inoculated organism is most susceptible to chloramphenicol given that it had the smaller relative zone diameter

 

before assuming drug sensitivity, you should look at the ranges reported in the CLSI table

before assuming drug sensitivity, you should look at the ranges reported in the CLSI table

These are the results of an antimicrobial susceptibility test. Which drug would you prescribe to your patient based on the results?

 

ampicillin (AM)

 

tigecycline (TGC)

 

chloramphenicol (C)

 

erythromycin (E)

tigecycline (TGC)

Rather than measure the zone diameters, can you make an accurate treatment determination by comparing the presence and relative size of the zones of inhibition?

 

No. Each zone of inhibition must be measured and compared with the CLSI table values to determine the best treatment option.

 

Yes. The best treatment option is a drug whose disk has the largest zone of inhibition.

 

Yes. The best treatment option is a drug whose disk has a zone of inhibition (regardless of size.

 

Yes. The best treatment option is a drug whose disk has the smallest zone of inhibition.

No. Each zone of inhibition must be measured and compared with the CLSI table values to determine the best treatment option.

These are the results of your patient’s antimicrobial susceptibility test. Using the CLSI table, determine which drug(s), if any, could be used to treat your patient. Select all the apply

 

rifampin (R)

 

gentamicin (GM)

 

trimethoprim-sulfamethoxazole (SXT)

 

chloramphenicol (C)

 

cephalothin (CF)

rifampin (R)
chloramphenicol (C)

Your lab partner decides to take a shortcut when inoculating the bacteria by swabbing from side to side in only one direction prior to disk placement. Which of the following would most likely result from this inoculation technique?

 

the plate would have overabundant growth

 

the bacteria would exhibit resistance to each of the antimicrobial drugs tested

 

the plate would have no growth

 

the plate would have gaps where the swab missed

the plate would have gaps where the swab missed

These are the results of an antimicrobial susceptibility test. Given the results, what should you do next?

 

repeat the experiment due to improper plate inoculation

 

add an additional drug disk in the area of confluence and re-incubate

 

measure each zone of inhibition and record the results

 

repeat the experiment because the plate is contaminated

Repeat the experiment due to improper plate inoculation

Based on the measurement in the image, what is the zone diameter?

 

3.6mm

 

36mm

 

18mm

 

1.8mm

 

36mm

Your Lab partner is examining an antimicrobial susceptibility test plate and takes note of the sizes of the zone diameters. Your partner assumes that the test microbe is more susceptible to COT than to VA. How do you respond?

 

Incorrect; the test microbe will be the most susceptible to the antimicrobial with the smallest zone diameter.

 

Correct; the test microbe will be the most susceptible to the antimicrobial with the largest zone diameter.

 

Not necessarily; the individual zone diameters must be compared with the ranges listed in the CLSI table to determine drug effectiveness.

 

Not necessarily; the zone diameter should not be used to determine the effectiveness of an antimicrobial drug.

Not necessarily; the individual zone diameters must be compared with the ranges listed in the CLSI table to determine drug effectiveness.

Which of the following can be determined by the antimicrobial susceptibility test?

 

the minimum inhibitory concentration of the drug

 

the in vitro susceptibility of the test microbe to the drug

 

the in vivo effectiveness of the drug on the test microbe

 

the drug’s mechanism of action

the in vitro susceptibility of the test microbe to the drug

Without measuring zone diameters, which drugs are Escherichia coli definitely resistant to?

 

You cannot determine this because you must measure the zone diameter and compare it to the CLSI table values

 

SXT and P

 

CC, CIP, and S

 

P, OX, CC, and E

P, OX, CC, and E

Measure the zone for streptomycin (S) using the provided ruler. Determine the effectiveness of S on Escherichia coli.

CLSI Values for S: resistant ≤ 11mm, intermediate 12-14mm, susceptible ≥15mm

 

susceptible

 

intermediate

 

resistant

susceptible

Measure the zone for tetracycline (TE) using the provided ruler. Determine the effectiveness of TE on Escherichia coli.

CLSI Values for TE: resistant ≤ 14mm, intermediate 15-18mm, susceptible ≥19mm

 

intermediate

 

resistant

 

susceptible

 

intermediate

Measure the zone for chloramphenicol (C) using the provided ruler. Determine the effectiveness of C on Escherichia coli.

CLSI Values for C: resistant ≤ 12mm, intermediate 13-17mm, susceptible ≥18mm

 

intermediate

 

resistant

 

susceptible

 

susceptible

Measure the zone for amoxicillin (AMC) using the provided ruler. Determine the effectiveness of AMC on Escherichia coli.

CLSI Values for AMC: resistant ≤13mm, intermediate 14-17mm, susceptible ≥18mm

 

susceptible

 

resistant

 

intermediate

resistant

Measure the zone for trimethoprim sulfa (SXT) using the provided ruler. Determine the effectiveness of SXT on Escherichia coli.

CLSI Values for SXT: resistant ≤10mm, intermediate 11-15mm, susceptible ≥16mm

 

intermediate

 

resistant

 

susceptible

susceptible

Measure the zone for ciprofloxacin (CIP) using the provided ruler. Determine the effectiveness of CIP on Escherichia coli.

CLSI Values for CIP: resistant ≤12mm, intermediate 13-16mm, susceptible ≥17mm

 

susceptible

 

resistant

 

intermediate

susceptible

Without measuring zone diameters, which drugs is/are Pseudomonas aeruginosa possibly susceptible to?

 

C, TM, and CIP

 

AMC, SXT, and P

 

CIP only

 

CC, TM, CF

C, TM, and CIP

Measure the zone for ciprofloxacin (CIP) using the provided ruler. Determine the effectiveness of CIP on Pseudomonas aeruginosa.

CLSI Values for CIP: resistant ≤12mm, intermediate 13-16mm, susceptible ≥17mm

 

susceptible

 

resistant

 

intermediate

susceptible

Measure the zone for tobramycin (TM) using the provided ruler. Determine the effectiveness of TM on Pseudomonas aeruginosa.

CLSI Values for TM: resistant ≤12mm, intermediate 13-14mm, susceptible ≥15mm

 

susceptible

 

resistant

 

intermediate

susceptible

Measure the zone for chloramphenicol (C) using the provided ruler. Determine the effectiveness of C on Pseudomonas aeruginosa.

CLSI Values for C: resistant ≤12mm, intermediate 13-17mm, susceptible ≥18mm

 

resistant

 

susceptible

 

intermediate

 

intermediate

Measure the zone for vancomycin (VA) using the provided ruler. Determine the effectiveness of VA on Streptococcus aureus.

CLSI Values for VA: resistant ≤9mm, intermediate 10-11mm, susceptible ≥12mm

 

susceptible

 

intermediate

 

resistant

susceptible