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.