Clinical details/ conditions Standard media Incubation Cultures read Target organism(s) Temp. °C Time UTI Screening in pregnancy for asymptomatic bacteriuria by culture CLED agar or Chromogenic agar 35–37 Air 16–24hr ≥16hr Enterobacteriaceae Enterococci Lancefield B streptococci Pseudomonads S. saprophyticus Other staphylococci S. aureus Enteric fever screen* Mannitol selenite broth subcultured to: XLD 35–37 35–37 Air Air 16–24hr 16–24hr N/A ≥16hr S. Typhi S. Paratyphi For situations, add the following: Clinical details/ conditions Supplementary media Incubation Cultures read Target organism(s) Temp. °C Atmos. Time Urine of patients in Intensive Care, Special Care Baby Units, Burns Units and any from a Transplant Unit or if yeast have been seen in microscopy Sabouraud agar 35–37 Air ≥40hr Fungi Multipoint culture using agar plates Susceptibility testing agar seeded with B.subtilis (NCTC 10400) 35–37 Air ≥16hr Antimicrobial substances Optional media Incubation Cultures read Target organism(s) Temp. °C Time If sterile pyuria and no antimicrobials detected Fastidious anaerobe agar 35–37 anaerobic ≥40hr Anaerobes Streptococci Chocolate agar 35–37 5-10% CO2 ≥40hr Fastidious organisms
Appendix 3: Guidance for the interpretation of urine culture Note: This is intended for guidance only - supplementation with local reporting policies may be necessary. Growth cfu/L No. isolates Specimen type Clinical details/microscopy influencing report* Laboratory interpretation Susceptibility testing recommended Comments to consider 108 1 Any None Probable UTI Yes If old specimen or no pyuria consider repeat to confirm Consider SPA or CCU if bag specimen 2 Each org 108 or 108 and 107 MSU, CCU, SCU, BAG WBC present Symptomatic Possible UTI – colonisation, faulty collection or transport Yes Consider repeat to confirm CSU, (IL) Indwelling catheter Neurogenic bladder Probable colonisation No – Consider keeping plates ≤ 5d in case patient becomes septic Consider discuss if patient systemically unwell and therapy required 2 3 1 organism predominant at 108 or 107 Any None Possible UTI – ?colonisation, faulty collection or transport Yes, predominant organism If old specimen or no pyuria consider repeat to confirm Consider SPA or CCU if bag specimen ≥ 3 Mixed growth - none predominant Any None Faulty collection or transport No Heavy mixed growth – probable contamination. Consider repeat if symptomatic 107 – 108 1 Any WBC present Symptomatic Possible UTI – patient evaluation necessary Yes Consider repeat to confirm 2 1 predominant at 107 Any WBC present Symptomatic Children Probable UTI with predominant species 2nd isolate probable contamination Yes, predominant organism but suppress results Consider repeat or SPA/CCU Sensitivities are available if required 1 at < 107 or 107 – 108 but not predominant None Probable contamination No Mixed growth – probable contamination ≥ 3 1 organism predominant at 107 Any WBC present Symptomatic Possible UTI with predominant species. Others probable contamination No – keep plates ≤ 5d if catheter specimen in case patient becomes septic Mixed growth – consider repeat if symptomatic Any combination CSU Indwelling catheter Neurogenic bladder Colonisation No – keep plates ≤ 5d in case patient becomes septic Please discuss if therapy indicated
Appendix 3 (continued): Guidance for the interpretation of culture Note: This table is intended for guidance only – supplementation with local reporting policies may be necessary. Growth cfu/L No. isolates Specimen type Clinical details/microscopy influencing report Laboratory interpretation Susceptibility testing recommended Comments to consider 106 – 107 1 MSU, CCU, CSU, IL Symptomatic female Prostatitis WBC present Possible UTI – clinical evaluation necessary Yes Consider repeat to confirm 2 Each org 106 - including possible pathogen, eg E. coli or S. saprophyticus Any Possible UTI – clinical evaluation necessary Yes Consider repeat to confirm 105 – 108 1 SPA, CYS, (SCU) None Probable UTI Yes 2 Each 106 WBC present Probable UTI – patient evaluation necessary Yes ≥3 1 organism predominant at 106 WBC present Probable UTI – patient evaluation necessary Yes, predominant organism Mixed growth: Consider repeat to confirm No growth ie: < 106 if 1 μL loop used < 105 if 10 μL loop used Any None or asymptomatic No UTI Symptomatic Marked/persistent pyuria • Patient on antibiotics? • Consider Chlamydia, AFB etc • Fastidious organism? • Consider bacteriuria < 105 cfu/L As appropriate MSU –- Midstream specimen; CCU – clean catch; SPA – Suprapubic aspirate; IL– Ileal conduit; CSU –- Catheter; SCU – Single, intermittent catheter (“in and out”); CYS – Cystoscopy * - see Introduction for interpretation of culture results