Microbiology Topics:Gram positive vs gram negative

Peptidoglycan Penicillin antibiotics

Extracellular structures Capsule – resists phagocytosis Fimbriae/pili – attachment Flagella – motility

Gene exchange Transformation Conjugation Transduction – bacteriophage

Anaerobes/aerobes Super-oxide dismutase/catalase hydrogen

peroxide and superoxide radicalQuantitative virulence

Lethal dose 50 Infectious dose 50

Pharyngitis Quinsy

o Unilateral pharyngeal paino Dysphagiao Deviated uvulao Tonsillar exudate

Otitis media Pneumonia, haemophilus, Moraxella Which ones can be vaccinated against? Complications: hearing loss, mastoiditis

cerebral abscess/cavernous sinus thrombosisSinusitis

Pathogenesis (blowing nose) Comp: meningitis, brain abscess, subdural

empyema, cavernous sinus thrombosis, orbital cellulitis, pott’s puffy tumour

Epiglottitis Presentation (drooling, fever, irritable,

dysphagia) High mortality Ceftriaxone Intubate

PneumoniaETEC

LT and ST Activates adenylate cyclase chloride Similar to cholera

EHEC Shiga toxin

Salmonella Pro-inflammatory cytokines activate innate

immune system inflammationShigella

Invasion, intracellular multiplication and adjacent spread

Comp: dehydration, septicaemia, keratoconjunctivitis, HUS

DrainageTriple therapy

Treatment for anaerobic infections (augmentin, piptaz, clindamycin, carbapenam)C. diff

Antibiotics predispose (which one most?) C.diff toxin cell cytotoxicity assay Rx: stop antibiotic, fluid replacement, surgery if

needed, oral or IV metro, oral vanc (why?)C. botulinum

Tetanospasmin retrograde axonal transport Pre-synaptic inhibitory synapses Metro, debride, tetanus Ig, ICU

Urine collection Low level, high contamination, sterile Protein, blood, nitrate reductase, leukocyte

esteraseHospital vs community

Ecoli for both Pseudomas more in hospital

Skin and soft tissue When in doubt guess pyogenes or aureus

Hot tub folliculitis (pseudomonas)Impetigo (bullous – staph)Paronychia – s aureusCellulitis (spontaneous/wound staph or pyogenes fluclox)Fresh water – aeromonas hydrophila/salt water vibro vulnifcusDog/cat – pasteurella multocidaNec fasc – pyogenes, staph, perfringens debridementMastitis - GBSOpportunistic pathogens (Cryptococcus neoformans) vs prmary pathogens (Cryptococcus gattii)Structural differences between basidiomycetes, ascomycetes and zygomycetesDermatophytes?Meningitis

Acute vs chronic Presentation Neisseria, pneumonia, influenza, listeria, ecoli,

GBS LP, IV ceftriaxone, dexamethasone if

pneumococcal Vaccine prevention which capsular types? (BC)