Microbiological Virulence Factors Flashcards
Components of bacteria
Cytoplasmic membrane Cell wall Capsule Flagella Pili (Fimbriae)
What does the cytoplasmic membrane of bacteria consist of?
Proteins and phospholipids (except mycoplasma) No sterols (only in eukaryotes)
Functions of bacterial cytoplasmic membrane
Synthesis and export of cell wall components
Respiration
Secretion of extracellular enzymes and toxins
Uptake of nutrients by active transport mechanisms
Functions of bacterial cell wall
Protective-supply rigidity to withstand osmotic and mechanical stress
Responsible for the shape
The firm base for pili, fimbriae, flagella
Contains antigens (important for virulence and host antibody formation)
Gram positive cell wall appearance
Plasma membrane
Peptidoglycan (thick) and teichoic acids
Gram negative cell wall appearance
Plasma membrane
Peptidoglycan (thin)
Outer membrane
Functions of capsule
Anti-phagocytic activity
Adhesion
Laboratory diagnostic tests
Vaccines
Functions of pili/fimbriae
Adhesion
Anti-phagocytic activity
Sex pili- transfer DNA by conjugation
Intracellular structures of bacteria
Nucleoid
Ribosomes
Inclusion granules
Endospores
Which bacterial identification tests consider enzyme production?
Urease
Catalase
Coagulase
Oxidase
Which bacterial identification tests consider toxic production?
Protein synthesis inhibitors
Haemolysins
Superantigens
Which severe infections is staphylococcus aureus seen in?
Skin/soft tissue
Endocarditis
Osteomyelitis
Streptococcus shape
Gram positive cocci in chains
Functions of endospores
Protection- survive drying, heat, dehydration, radiation
What is the treatment for anthrax?
Prevented/treated with ciprofloxacin
