Final revision microbio

penicillin variations

penicillin G, ampicillin

ampicillin

semi-synthetic penicillin, coliform bacteria

cephalexin

1st generation, gram positive cocci

cefuroxme

2nd gen, decrease gram positive cocci activity, increase stability in gram negative

cefotaxime

3rd gen, meningitis treatment, able to cross blood brain barrier

clavulanic acid

beta-lactamase inhibitor, competitive

vancomycin

glycopeptide, binds with peptidoglycan side chain terminus, steric inhibition of synthetase, severe MRSA infection

Inhibitory test

Categorical and numerical, cheap fast standardised, larger zone = sensitive isolate

stokes method

numercial inhibitory test comparison, categorising sensitive, resistant and intermediate, lack of standardisation in media prep and inoculum

Numerical inhibitory test

quantify in vitro susceptibility (MIC), used when zone size are close

Cidal testing

quantify cidal acitvity in vitro (MBC), used when severe infection requires bacterial killing and growth inhibition, limited by time, poor reproducibility

BSAC method

relate zone size to MIC breakpoints, everything standardised, template required, continous MIC distribution cause mislabelled organisms which affects reproducibility

Kass 1956

100k per mL for significant bacteriuria

Pyelonephritis

urine buildup cause backflow to kidney, duplicated urether

Chlamydia trachomatis

elementary and reticulating body, tetracycline quinolones macrolides

Neisseria gonorrhoea

Haemin yeast extract culture

Genital candidosis

yeast infection, imidazole treatment

Trichomoniasis

trichomonas vaginalis, protozoic parasite, metronidazole treatment

Vaginosis

normal lactobacilli → high conc. anaerobes and G. vaginalis, pH increase, clue cell

Syphilis

treponema pallidum, parasitic bacterium, dark ground microscopy

syphilis disease progression

Canker, acne vulgaris, irregular pupil/cardiovascular, joint pain @ shin, muscle and neuron damage

HIV management

PrEP/PEP, U=U

U=U

HIV patients on treatment + undetectable viral load untransferrable during sex

vaccination options

HPV, hep A (faecal oral organism), hep B (blood IV users)

Impetigo

Flucloxacillin, erythromycin if penicillin allergic

Bullous impetigo (SSSS)

epidermolytic toxic secreted through phages, skin lifting

Abscess

Furuncle and carbuncle

Cellulitis diagnosis if blood culture doesn’t work

ASO titres

Erysipelas

cellulitis @ head and neck only

Necrotising fasciitis disease progression

infection @ deep tissue, destruction with loss of function, pathogen meets ischaemic tissue, hyaluronidase virulence facilitate infection, septicaemia

C. canimorsus

dog

Pasteurella multocida

cats

Strep. dysgalactiae

group C/G, SDE from horse

pharynx infection

GAS,strep. dysgalactiae, corynebacterium diphtheriae

corynebacterium diphtheriae

tox gene, ELEK plate, Hoyle’s medium, black dots

Hoyle’s medium

tullurite selective growth

Acute epiglottitis

Haemophilus influenzae HiB, film formation

Chronic bronchitis

Moraxella catarrhalis

Cystic fibrosis progression

s. aureus, H. influenzae, variants

psuedomonas aeruginosa

extra mucus, CF variant

Burkholderia cepacia

extreme antibiotic resistance, CF variant

S. maltophilia

waterborne, CF variant

Whooping cough

Bordetella pertussis, charcoal blood agar, agglutination antiserum

community acquired pneumonia

60% strep. pneumoniae, 15% H. influenzae

Nosocomial pneumonia

Enterobacteriaceae, gut to lung through intubation

Atypical pneumonia

legionella pneumophila, no typical bacterial cell wall

Aspiration pneumonia

Inhaling vomit , gastic acid lung damage

Strep pneumonia identification

alpha haemolysis, draughtman colonies, optochin sensitive

legionella culture

growth only on L-cystine enriched BCYE yeast agar

TB diagnosis

ZN acid fast stain for microscopy, slow egg based culture, PCR faster

Vertical audit

procedure QC

Horizontal audit

multi-department review

ZN stain

mycobacteria, warm stain for carbon fuchsin staining

wet prep

candida

Stool sample

clostridium, endospore when nutrients low

capsular staining

postive - bacteria stain, light halo, heat sixation

negative - background stain, clear halo, no heat fixation

Propionic bacteria

acne, skin flora

MFG

breast milk, nutrient support, bifidobacteria, anti-inflamm proteins, dynamic