Microbiology Module 4 Study Questions

Module 4 Study Questions

• Question 1: Transmission of M. tuberculosis

  • Inhalation of aerosols
  • Puncturing the skin
  • Eating/drinking contaminated food/water

• Question 2: Positive TB Skin Test

  • A positive test shows a red, indurated (hardened) area.
  • A positive test does not involve any skin changes.
  • A positive test indicates exposure to Mycobacterium tuberculosis (MTB).
  • A positive test suggests the individual might have active tuberculosis or latent tuberculosis

• Question 3: Interferon-gamma release assays (IGRA)

  • Performed using a blood sample.
  • Less prone to error based on the reader's subjectivity
  • Effective in distinguishing latent from active tuberculosis.
  • Not affected by the BCG vaccine

• Question 4: Gram-stained appearance of mycobacteria

  • Gram-positive rods
  • Poor staining performance

• Question 5: SPUTUM sample collection procedure for Mycobacterial cultures -Three-five morning (3-5) samples over a week

• Question 6: URINE sample collection procedure for Mycobacterial cultures -Three-five morning (3-5) samples over a week

• Question 7: Specimen processing procedures

  • CSF: Decontaminate specimen & inoculate 2 sets of media (30°C & 35°C)
  • Sputum: No decontamination. Centrifuge & inoculate media

• Question 8: Handling gastric aspirates -Neutralize specimen with sodium bicarbonate -Store in a refrigerator, if not processed within four hours

• Question 9: Rapid-growing mycobacteria -M. abscessus -M. fortuitum-chelonae

• Question 10: Time for rapid-growing mycobacterial growth -Less than 3 days.

• Question 11: Evaluation of decontamination procedures -High contamination rate indicates a weak decontamination process

• Question 12: Function of reagents -N-acetyl-L-cysteine: Decontaminating agent -2% NaOH: Mucolytic agent

• Question 13: Middlbrook Agar storage requirements:

  • Store in the dark. Avoid light.
  • Incubate plates in air, not CO2

• Question 14: Mycobacterial media types -Lowenstein-Jensen (LJ) media is agar-based. -Middlebrook 7H10 media is egg-based. -Petragnani media is egg-based. -Mitchison 7H11 media is egg-based. -American Thoracic Society (ATS) media is egg-based

• Question 15: Pigment production by groups (Matching)

• Question 16: Positive test results (Matching)

• Question 17: Organism descriptions (Matching)

• Question 18: Clinical significance of M. gordonae -True, M. gordonae is clinically significant

• Question 19: Mycobacterial culture incubation -Incubate at 35-37°C in air, hold plates for 8 weeks.

• Question 20: Additional steps for soft-tissue specimen culture -Add a fungal culture plate (PDA or SAB media) and a plate containing hemin (CHOC media.) -Incubate all plates at 30°C

• Question 21: Ziehl-Neelsen or Kinyoun stain positive result -Red rods

• Question 22: Potassium permanganate in fluorochrome stain: -Used to stain the background blue

• Question 23: Positive and negative controls in acid-fast stains -True

• Question 24: Dimorphic fungi -Blastomyces dermatitidis -Coccidioides immitis -Histoplasma capsulatum

• Question 25: Dimorphic fungi growth conditions -Yeast form at 37°C, mold form at 25°C or 30°C

• Question 26: Malassezia furfur culture media -Media supplemented with lipids.

• Question 27: Malassezia furfur and systemic disease risk -Patients on long-term antimicrobial therapy.

• Question 28: Malassezia furfur causes (Matching/disease associated with organism)

• Question 29: SPUTUM collection procedure for mycology cultures -3–5 morning samples over a week (3-5)

• Question 30: Penicillium species and disease -Penicillium species is not known to cause diseases. -This is false

• Question 31: Testing for cryptococcal meningitis -Cryptococcal antigen test

• Question 32: Effect of cycloheximide on Cryptococcus -Cycloheximide inhibits Cryptococcus growth -This is true

• Question 33: Gram stain reaction for Nocardia -Gram-positive branching rods.

• Question 34: Organism also sharing similar gram stain reaction with Nocardia -Actinomyces israelii

• Question 35: Stain for identifying Nocardia -Modified Acid Fast stain

• Question 36: Disease caused by Pneumocystis jirovecii -Pneumonia

• Question 37: Stains for visualizing Histoplasma capsulatum and Pneumocystis jirovecii -GMS stain and KOH

• Question 38: Dermatophyte macroconidia descriptions (Matching)

• Question 39: Organism descriptions (Matching)

• Question 40: Incubation conditions for mycology cultures -Incubate at 35-37°C in air; hold plates for 8 weeks.

• Question 41: Stool samples for Ova and Parasite exams -Two stool samples, one day apart.

• Question 42: Charcot-Leyden crystals -Degradation products of eosinophils

• Question 43: Protozoan stages in different stool types -Liquid stools: Cysts. Forme stools: Trophozoites

• Question 44: Parasitic infection and best specimen for diagnosis (Matching)

• Question 45: Handling of specimen-related questions (Procedures and processing guidelines for specimen handling and collection)

• Question 46: Specimens with PVA preservative -Permanent stained smear.

• Question 47: Specimens and appropriate staining (Matching and procedures for specimens in formalin and other preservatives)

• Question 48: Intended purposes of procedures (Matching: Procedures and what they do to specimens and diagnoses)

• Question 49: Plasmodium species characteristics (Matching)

• Question 50: Plasmodium species causing most severe malaria -Plasmodium falciparum

• Question 51: Organism and appropriate stain (Matching: organisms and stains based on visual determination)

• Question 52: Organisms and diseases they cause (Matching)

• Question 53: Parasitic classification of organisms (Matching)

• Question 54: Organism descriptions (Matching)

Test your knowledge on tuberculosis transmission, diagnosis, and microbiological techniques with these study questions. This quiz covers important concepts related to Mycobacterium tuberculosis, including TB skin tests and sputum sample collection. Enhance your understanding of the microbiology surrounding tuberculosis.