Definitions Flashcards
How do you prepare a Gram stain?
Primary stain affects both bacteria–>iodine/mordant forms a complex–>Alcohol dehydrates peptidoglycan to be impermeable but leaves the cell in Gram- bacteria–>counter stain/safranin stains Gram - pink
Characteristics of Gram + bacteria
teichoic acids linked to cytoplasmic membrane and cell wall acids link to peptidoglycan, provide antigen specificity
Characteristics of Gram - bacteria
outer membrane with proteins, phospholipids, LPS, to provide structural activity, toxic to mammalian cells
Mesosomes
Gram + bacteria, folds of cell membrane that help DNA attachment and septum formation
Spores
cytoplasmic structures in Gram + bacteria; dehydrated, durable, and can survive. Begins with depleted nutrients and releases with all necessary components to be a vegetative cell THIS is why autoclaving is important
Glycocalyx
protects against dehydration, helps with nutrition, antigenic determinant, mediates surface attachments
Fimbriae/pili
Mediate pathogen adherence to epithelial cells
Triple Sugar Iron Agar Medium
Detects carbs and hydrogen sulfide production; has lactose/sucrose/glucose; metabolism of glucose–>acid butt and alkaline slant; lactose or sucrose–>acid tube and yellow and produces gas; alkaline reaction shows peptone degradation; alkaline or no change shows peptones degrade aerobically; if H2S produced then black precipitate formed
Plasmid
has genes for antibody resistance, virulence, chemical resistance, degradation of environmental contaminants, sex pilus
Transposons
move from one site to another, have short inverted sequences on ends
Mutualism
both host and microbe benefit
Commensalism
microbe benefits and host is not affected
Pathogenicity
potential of an organism to cause disease
Virulence
degree or severity of disease, decreased by attenuation
opportunistic
microbe that can cause disease if host resistance is lowered or put into another location
