Mikrobiologi och Normalflora

Mikrobiologi

• Normalflora: Microorganisms naturally residing on and in the human body without causing illness. Found on skin, mouth, intestines, and vagina. Normal flora protects against pathogens and supports bodily functions, like digestion.

• Endogenous vs. Exogenous Infections:

  • Endogenous: When the body's own normal flora cause infection, often due to weakened immune system.
  • Exogenous: Infection caused by microorganisms from outside the body, through transmission from another person.

• Absence of Bacteria in Internal Organs: Internal organs lack the environments (nutrients, pH) that promote bacterial growth due to physical barriers (skin, mucous membranes) and an effective immune system.

• Anaerobic Microorganisms in Mouth/Intestine: Anaerobes thrive in oxygen-poor environments such as gum pockets and the intestines, where low oxygen levels enable them to survive and grow.

• Intestinal Microflora Benefits:

  • Nutrient Breakdown: Aid in breaking down complex carbohydrates
  • Vitamin Production: Produce vitamins like K and some B vitamins.
  • Pathogen Protection: Outcompete harmful bacteria
  • Immune System Enhancement: Boost the immune system and tolerance to beneficial microbes
  • Inflammation Regulation: Help regulate immune responses

• Antibiotic Impact on Microbiome: Antibiotics can disrupt the normal flora by killing both harmful and beneficial bacteria, leading to imbalances (e.g., diarrhea, fungal infections). Different antibiotics have varied effects based on their targeting spectrum (broadspectrum or narrowspectrum).

• Individual Variation in Antibiotic Response: Antibiotic effects on normal flora vary between individuals due to differences in gut flora, age, immune status, and past antibiotic use.

• Endogenous Flora and Infection: Endogenous (normal) flora can cause infections if located in the wrong places (e.g., intestinal bacteria in the urinary tract) or if the person's immunity weakens.

• Operational Infections: Operating room staff can bring/cause infections through unsterile techniques and failing to follow proper procedures.

• Microorganism Spread Routes:

  • Direct Contact: Transmission through physical contact with infected people or surfaces.
  • Airborne (Aerosol): Transmission through tiny droplets from coughs or sneezes spreading through air for extended periods.
  • Droplet Transmission: Through large droplets produced by sneezing or coughing, which do not travel in the air as long as airborne transmission.
  • Fecal-Oral: Bacteria spread via contaminated food or water.
  • Indirect Contact: Transmission via contaminated surfaces or objects.
  • Bloodborne: Transmission through blood contact (e.g., Hepatitis B, HIV).

• Opportunistic Microorganisms: Microorganisms that don't usually cause illness but can do so when the host's defences are weakened.

• Vaccine Types (Active vs Passive):

  • Active: Stimulates the body to build its own antibodies (long-lasting immunity). Involves using dead or weakened microorganisms.
  • Passive: Provides antibodies from another person (short-lived immunity). Obtained from donor.

• Vaccination Programs: Designed to protect against serious illnesses, prevent disease outbreaks, and protect the population at large. Vaccination helps develop herd immunity.

• Antimicrobial Medications: Substances that stop or kill the growth of microbes. Examples include antibiotics (for bacteria), antifungals (for fungi), antivirals (for viruses), and antiparasitics (for parasites).

• Antimicrobial Resistance: Bacteria adapt and evolve so that antibiotics are ineffective against them increasing treatment difficulty. Bacteria gain resistance through mutations or genetic material transfer.

• Antimicrobial Resistance Factors: Factors contributing to antimicrobial resistance include overuse, inappropriate use, and inadequate treatment duration of antibiotics.

• Gram-Positive vs. Gram-Negative Bacteria: Gram-positive bacteria have thick cell walls that stain purple in a Gram stain, while Gram-negative have a thin cell wall that stains pink. These structural differences lead to variations in response to antibiotics

• Bacterial Structure and Components: Key components of bacterial cells include cell walls, cell membranes, cytoplasm, DNA, ribosomes, and flagella.

• Bacterial Toxins (Endotoxins vs Exotoxins): Both are harmful products, but endotoxins are part of the bacterial cell wall, released only when the cell bursts, whereas exotoxins are produced and secreted into the surrounding environment.

• Viruses vs. Bacteria: Viruses are smaller and require a living host cell for replication compared to bacterial cells, which have their own metabolic processes.

• Biofilm Formation: Bacterial colonies can form biofilms, which protect them from the immune system and antibiotics. This protection makes bacteria more resistant to medication.

• Healthcare-Associated Infections (HAIs): Infections acquired in healthcare settings, often through compromised medical equipment and inadequate infection control practices.

• Urinary Tract Infections (UTIs): Infections of the urinary system, broadly classified as either primary or secondary depending on their origin. Some pathogens are predisposed towards urinary tract infection.

• Common Bacterial and Viral Pathogens: Examples include various strains of bacteria, viruses like influenza and other respiratory illnesses, and specific pathogens associated with gastrointestinal issues.

• Basic Personal Hygiene Practices: Practices such as handwashing and proper disinfection of surfaces to prevent pathogen spread.

• Infection Control in Healthcare Settings: Procedures and practices to prevent the spread of infection among patients and healthcare providers.