Infectious Diseases

Major differences in cell wall structure

- Single membrane consisting of a thick peptidoglycan layer (40+ layers of chain link fence)- No lipoploysaccarides- Resist lysis, but can still be opsonized- Teichoic Acids and lipoteichoic acids can protrude wall and give antigenic identification

- External peptidoglycan wall is absent- inner and outer lipid bilayer membranes seperated by peptidoglycan layer, with outer membrance having lipopolysaccharid molecules

- do NOT have a peptidoglycan cell wall but have one composed of fatty acids and waxes-similar to gram positive bacteria-cell wall components mycolic acid, Wax D, cord factor, arabinogalactans, and sulfolipids

Spiral bacteria --- Treponemes, Borrelias, Leptospiras, Spirillium

Pathogenic Filamentous bacteria--- Actinomyces, Nocardia, Mycobacteria

Gram positive bacteria --- Staphylococcus, Streptococci

Propels, allowing motility and responding to chemotaxis

-hair-like; proteins that have two unrelated functions: adherence and genetic exchange

The protein coat on the bacteria's surface that impacts virulence

-certain gram positives only - both anaerobes and aerobic-metabolically inactive, will develop in response to stress-resistant to heat or desiccation

-usually circular and can be transmissible between cells by genetic exchange (conjugation)-some encode virulence properties, antibiotic resistance

-Organ system approach: what normally causes disease in this location-Gram stain approach: used to support empiric treatment before cultures are completed

- greater propensity to cause abscesses (wall themselves off and create their own environement)

Streptococcus pneumoniae (+)Neisseria meningitidis (-)Hemophilus influenzeListeria monocytogenes