Unit 1- Taxonomy Flashcards
Frank Pathogens
Cause disease in any host, considered a pathogen when isolated
Opportunistic Pathogens
Capable of causing disease given the opportunity, often normal part of flora, capable of causing disease in normally sterile tissues
Non-Pathogens
Can cause disease in hosts with weak immune system
D=N*V/R
Disease equals number of organisms times virulence divided by resistance
Bacterial Classification Schemes
Speed up identification using a limited number of characteristics
Bacterial Nomenclature
Binomial system with specific naming conventions that assigns a genus and species
Bacterial Identification
Based on morphological, biochemical, and serological traits
Gram-Positive
Thick peptidoglycan wall and appear blue/violet after staining
Gram-Negative
Thin peptidoglycan wall but lipid-rich outer membrane and appear red after staining
Gram Stain Procedure
Make a thin smear, stain with crystal violet, stain with Gram’s iodine, stain with safranin, rinse
Peptidoglycan Network
Lyseine and alanine are linked
β-Lactams
Bind penicillin-binding proteins and inhibit peptidoglycan synthesis
Lysozyme
Breaks bonds between tetrapeptides in peptidoglycan network
Disruption of Peptidoglycan
Lysozyme or penicillin will cause cytoplasmic membrane blebbing, and fragmentation
Acid Fast Bacteria
Mycolic acids connect muramic acid and lipids and prevent acid decolorization, staining red
Lipopolysaccharide
Endotoxin in gram-negative bacterial outer membrane, promotes secretion of pro-inflammatory cytokines in macrophages
Bacteremia
Bacteria in blood