Lab One: Multicellular Parasites

Biology 431 Currently - neonatal septicemia, pneumonia, meningitis Gram (+) Cocci Group B Carbohydrate - NAG/rhamnose/galactose Chapters 22-24 Colonize lower GI & GU, 10-30% pregnant women GU

Staphylococcus 60% infants colonized, increases with premature or Major groups - coagulase (+) aureus vs. (-) others. prolonged delivery; post-delivery infection possible.

External Structures pneumoniae - Nongroupable, alpha hemolytic Capsule - polysaccharide, 11 serotypes, antiphagocytic Diseases: pneumonia, sinusitis, otitis, meningitis Peptidoglycan endotoxin-like - fever, WBC, complement Polysaccharide capsule - 90 types, antiphagocytic Teichoic acid binds host mucosal fibronectin receptors IgA protease - digests IgA, prevents binding Protein A - binds IgG, prevents Ab clearance Pneumolysin - digests cholesterol, pores Pneumococcal vaccine, anti-capsule for 23 strains Toxins - mostly aureus Cytotoxins (A, B, D, G) - hemolytic, mostly WBC/RBC Viridans group also nongroupable - cavities, Exfoliative - protease, target skin desmosomes… endocarditis. causes SSSS/neonates; impetigo/nosocomial, AIDS… Enterotoxins (50%) - 8 different, acid/heat-stable, Sag Enterococcus TSS (15%) - tampon-associated, invasive and SAg Will not cover extensive list of others, Table 24.1-2

Flesh-Eating/Invasive Enzymes - most aureus Enterococcus - Virulence, Disease, Treatment Catalase: neutralize H2O2, metabolic or phagocytic Surface adhesin protein - bind GI and vaginal mucosa Hyaluronidase: hydrolyze connective tissue, spread Secrete - hemolysins, proteases, bacteriocins Lipase: survival in sebaceous areas, invasion Inherently resist many antibiotics; serious nosocomial... Fibrinolysin/Staphylokinase: dissolve fibrin clots UTI, surgical (peritoneum/heart), blood (endocarditis) Penicillinase: plasmid-passed antibiotic resistance Careful antibiotic selection, use - new drug development Coagulase: covered in lab gallinarum more prominent human GI flora; faecalis Other aureus Diseases - Most Hematogenous more disease-associated. Enterocolitis - C. difficile-like, long-term antibiotics Bacteremia - bacteria in blood, 50% nosocomial Endocarditis - 50% fatal rapid deterioration Pneumonia - several, all associated with abscesses Osteomyelitis - bone infection, pain, high fever

Non-aureus Diseases UTI - mostly saprophyticus, lab Endocarditis - mostly epidermidis and lugdunensis… Native heart valves - malformed, genetic, disease Nosocomial plastic devices, prosthetics - 1 year later

Streptococcus Hemolysis subgroups - lab

External Structures - pyogenes Capsule - polysaccharide, Lancefield (surface A-G)… pyogenes = Group A - 10% weight, NAG/rhamnose M Protein - 100 types, antiphagocytic/opsonization Lipoteichoic acid binds host mucosal fibronectin

Other Virulence Factors - pyogenes Pyrogenic Exotoxins - SAg, toxic shock, rash, fever… Streptolysin - hemolytic for RBC, WBC - more in lab Streptokinase - lysis of fibrin clots, disease spread DNAse - nucleases, target pus to reduce viscosity C5a Peptidase - destroys key complement protein

Outcomes - pharyngitis, varying skin infections, Scarlet & Rheumatic Fever/Arthritis, glomerulonephritis. agalactiae - Group B, beta hemolytic Historically puerperal sepsis - childbirth, war wounds