LA

Microbiology and Disease Control Flashcards

BSL Levels

  • BSL-1: Low Risk/minimal precaution (e.g., E. coli)
  • BSL-2: Moderate Risk/need PPE (e.g., Staph aureus)
  • BSL-3: High Risk/airborne precaution (e.g., Tuberculosis)
  • BSL-4: Extreme Risk/Full containment (e.g., Ebola)

Autoclave

  • Sterilizes materials using pressurized steam.

Sepsis

  • Disinfection on living tissue.

Biocide

  • The absolute death of microbes.
  • Bactericides: Kill bacteria.
  • Viricides: Inactivate viruses.
  • Fungicides: Kill fungi.

Bacteriostasis

  • Stops the growth of organisms.

Antisepsis

  • Process of applying antiseptics on the skin.

Degerming

  • Process of reducing microbial numbers by gently scrubbing living tissue with a mild chemical.
  • Examples: Handwashing and Alcohol Swab

Epidemiology

  • Field that studies the geographical distribution and timing of infectious disease occurrences.

Morbidity

  • The state of being diseased.

Chronic vs. Acute Disease

  • Chronic: Months, years, lifetime.
  • Acute: Short duration.

CFU

  • The number of microbial colony-forming units.

Critical/Semi/Non-critical Items

  • Critical: Must be sterile (e.g., catheter, IV tube).
  • Semi-critical: High level of disinfection (e.g., GI endoscope).
  • Non-critical: Clean (e.g., bed linens, stethoscope, gowns).

Fomites

  • Objects that carry viruses/bacteria.
  • Found on medical equipment/doorknobs.
  • They can spread infections around.

Disinfection

  • Reduces or kills most microbes.

Sanitization

  • Lowers the number of germs to safe levels.

Sterilization

  • Destroys all microbial life.

Physical Methods of Microbial Control

  • Controls microbial growth, including high temperature, radiation, filtration, and desiccation.
  • Often nonspecific to their target – they kill cells by disrupting membranes, damaging/denaturing proteins and nucleic acids, and degrading various chemicals.
  • Heat
    • TDP (Thermal Death Point)
    • TDT (Thermal Death Time)
    • DRT (Decimal Reduction Time)
    • Dry Heat, Moist Heat, Boiling
  • Pressure: Often used in the food industry to kill bacteria, yeasts, molds, parasites, viruses.
  • Salting
  • Radiation
  • Filtration

Essential Oils

  • A mixture of hydrocarbons that are extracted from plants.
  • Many are used in traditional medicine and for preserving products, including food.
  • Phenols and/or terpenes result in antimicrobial activity.

Use of Chlorines and Chloramines in Microbial Control

  • Chlorines: Used as a disinfectant.
  • Chloramines: Like NH_2Cl, used as a disinfectant.

Bioaccumulation of Metals

  • Heavy metal concentration increases and can have a toxic effect.
  • Heavy metals denature protein and impair cell function.

Metals That Control Microbes

  • Silver, Copper, Nickel, Zinc

Zone of Inhibition

  • It indicates how effective that antimicrobial is against the particular species being tested.
  • It's useful to see which one is most useful.

Antibiotics

  • Drugs used to kill or inhibit the growth of bacteria.
  • They are derived from natural sources like fungi (Penicillium) or bacteria (Streptomyces).
  • They treat bacterial infections, saving lives
  • Examples: Penicillin, Amoxicillin, ciprofloxacin

Paul Ehrlich

  • A German scientist who discovered a chemical compound to kill infectious microbes without harming the patient or healthy cells, specifically for Syphilis.

Alexander Fleming

  • Discovered Penicillin.
  • It was the first natural antibiotic able to effectively kill bacteria and treat deadly infections.
  • First in the UK

Bacteriostatic vs. Bactericidal Drugs

  • Bacteriostatic Drugs: Stop bacteria from growing.
  • Bactericidal Drugs: Kill bacteria directly. Immunocompromised patients must have or any life-threatening infection.

Narrow-spectrum vs. Broad-spectrum Antimicrobials

  • Narrow-spectrum antimicrobials: Target only specific bacterial pathogens. Infection must be known.
  • Broad-spectrum antimicrobials: Target many bacterial pathogens; covers many possibilities; used as prophylactics (prevents spread).

Drug Resistance

  • Microbes evolve in order to overcome the antimicrobial compounds due to overuse or misuse of antimicrobials.

Definition of Disease

  • A condition that disrupts normal body function, causing signs/symptoms and affecting health.

Infection

  • Invasion and growth of harmful microbes (bacteria, viruses, fungi) in the body.
  • Signs: Fever, Redness, Swelling, Pain, Pus/Discharge.

Infectious Disease

  • Caused by the direct effect of a pathogen and can be communicable (person to person) and contagious (easily spread person to person).

Iatrogenic Disease

  • Diseases that are contracted as a result of a medical procedure.
  • 5th leading cause of death in the world.