Basic Microbiology (MLT202) Quiz

Basic Microbiology (MLT202)

• Course taught by Dr. Mohamed Mohsen
• Evaluation and Assessment:
  • Final written examination (16th week, 50 points, 33.3% weighting)
  • Final practical examination (14th week, 50 points, 33.2% weighting)
  • Other assignments (Q1 - 4th week, 15 points, 10% weighting; Q2 - 8th week, 15 points, 10% weighting; Q3 - 12th week, 20 points, 13.3% weighting)

What is Microbiology?

• Microbiology is the study of small living organisms that are not visible to the naked eye
• Micro = small, bios = life, logos = science

Microbiology Definition

• Identification of microorganisms (bacteria, fungi, viruses, parasites) causing infections
• Testing for effective antibiotics

Specimen Collection Guidelines

• Obtain specimen during acute infection phase (within 2-3 days for viruses)
• Collect before antibiotics administered
• Sample appropriate site (aspirate or tissue preferred to swabs)
• Avoid contamination with normal or environmental flora
• Obtain sufficient quantity
• Use sterile, leak-proof container
• Properly label container
• Do not transport syringes with attached needles

Specimen Preservation and Storage

• Urine: Transport tubes with boric acid-glycerol if not processed within 2 hours of collection; store at 4°C for no more than 24 hours
• Stool for ova & parasites: Use appropriate preservative based on the procedure: PVA, 10% formalin, SAF, MIF, or others without formaldehyde/mercury (Ecofix, Parasafe); store at 4°C
• Sputum: No preservative needed, store at 4°C.
• Stool for culture: Use transport media (e.g., Cary-Blair); store at 4°C; expedite processing to avoid killing certain bacteria (e.g. Shigella)

Criteria for Rejection of Specimens

• Unlabeled or improperly labeled specimen
• Improper collection site
• Prolonged transit (over 2 hours without preservation)
• Improper temperature during transport/storage (leaking specimens)
• Specimens in non-sterile containers
• Improper transport medium
• Culture ampule not broken; swab dried out
• Improper swab (e.g., wood)
• Specimen received in formalin (other than stool for ova&parasites)
• Saliva instead of sputum
• Insufficient quantity

Basic Rules of a Microbiology Laboratory

• Wear protection (e.g. lab coat, gloves)
• Wash hands before and after handling specimens
• Disinfect work areas before and after use
• Sterilize equipment and materials
• Do not pipette by mouth
• Do not eat or drink in the lab
• Avoid skin and eye contact with chemicals