Urine Culture Urine Culture
Dec 13, 2015
Urine CultureUrine Culture
Urine Gram StainUrine Gram Stain
Urine Culture QuantitationUrine Culture Quantitation
Clean catch or catheterized urineClean catch or catheterized urinePlate = 1000 organisms/mlPlate = 1000 organisms/ml
Clean catch: >10Clean catch: >1055 orgs/ml orgs/ml
Suprapubic urineSuprapubic urine Any colony is significiantAny colony is significiant
Urine CulturesUrine Cultures
11 . .Plates initially read at 18-24 hrPlates initially read at 18-24 hr
22 . .All specimens plated after NOON of All specimens plated after NOON of the previous day, hold another the previous day, hold another overnightovernight
33 . .Gram positives take longer to growGram positives take longer to grow
Most Common Pathogens of Most Common Pathogens of Human Urinary TractHuman Urinary Tract
Community acquiredCommunity acquired– E. coliE. coli is most frequent pathogen isolated is most frequent pathogen isolated– KlebsiellaKlebsiella sp and other Enterobacteriaceae sp and other Enterobacteriaceae– Staphylococcus saprophyticusStaphylococcus saprophyticus
Hospital acquiredHospital acquired– E. coli, Klebsiella,E. coli, Klebsiella, other other Enterobacteriaceae Enterobacteriaceae– Pseudomonas aeruginosaPseudomonas aeruginosa– Enterococci and StaphylococciEnterococci and Staphylococci
Abbreviated IdentificationAbbreviated Identification
E. coliE. coli– Non-swarming, spot indole pos, oxidase Non-swarming, spot indole pos, oxidase
negneg1.1. Lactose positive (MacConkey or eosin Lactose positive (MacConkey or eosin
methylene blue), PYR (pyrrolidonyl methylene blue), PYR (pyrrolidonyl arylamidase) test positivearylamidase) test positive
2. 2. APIAPI
Abbreviated IdentificationAbbreviated Identification
Proteus Proteus spp.spp.– Swarming growthSwarming growth
– IndoleIndoleNegative: Negative: P. mirabilis/penneriP. mirabilis/penneri
– P. mirabilis: P. mirabilis: maltose neg, ornithine posmaltose neg, ornithine pos– P. penneri: P. penneri: maltose pos, ornithine negmaltose pos, ornithine neg
Positive: Positive: P. vulgarisP. vulgaris
Abbreviated IdentificationAbbreviated Identification
P. aeruginosaP. aeruginosa– Oxidase-positive bacillusOxidase-positive bacillus– Typical smell (grapes)Typical smell (grapes)– Colony morphology Colony morphology P. aeruginosa: P. aeruginosa:
metallic/pearlescent, rough, pigmented, metallic/pearlescent, rough, pigmented, mucoidmucoid
– Indole-negativeIndole-negative
Abbreviated IdentificationAbbreviated Identification CHROMagar Orientation CHROMagar Orientation
– Presumptive ID for some UTI pathogens Presumptive ID for some UTI pathogens E. coliE. coli (dark rose to pink) (dark rose to pink) Enterococci (turquoise blue)Enterococci (turquoise blue) S. saprophyticus S. saprophyticus (light pink to rose)(light pink to rose) S. agalactiae S. agalactiae (light blue-green to light blue)(light blue-green to light blue) Proteus-Morganella-ProvidenciaProteus-Morganella-Providencia group (brown) group (brown) Klebsiella-Enterobacter-SerratiaKlebsiella-Enterobacter-Serratia group (dark blue) group (dark blue)
– Issues and challengesIssues and challenges All except All except E. coliE. coli and enterococci require further ID and enterococci require further ID
– Small Small E. coli E. coli colonies require spot indole colonies require spot indole Poor growth of some gram-positive bacteria Poor growth of some gram-positive bacteria NonselectiveNonselective–– other pathogens may or may not other pathogens may or may not
produce color changeproduce color change
Abbreviated IdentificationAbbreviated Identification
Enterococcus Enterococcus spp.spp.– Cocci or coccobacilli in pairs and chainsCocci or coccobacilli in pairs and chains– >1 mm colonies>1 mm colonies– Non-hemolytic on SBANon-hemolytic on SBA– Catalase-negativeCatalase-negative– PYR-positivePYR-positive(pyrrolidonyl-(pyrrolidonyl--naphthylamide -naphthylamide
hydrolysis)hydrolysis)
S. agalactiae S. agalactiae (GBS)(GBS)– Cocci in pairs and chainsCocci in pairs and chains– Catalase-negativeCatalase-negative– Narrow zone of beta-hemolysis on SBANarrow zone of beta-hemolysis on SBA– Rapid hippurate hydrolysis test (beta strep only) Rapid hippurate hydrolysis test (beta strep only) OROR– Test for CAMP factor (spot or O/N) Test for CAMP factor (spot or O/N) OROR– Typing by particle agglutinationTyping by particle agglutination– R/O beta hemolytic R/O beta hemolytic EnterococcusEnterococcus (PYR+) (PYR+)
Abbreviated IdentificationAbbreviated Identification
-hem Enterococcus
YeastYeast– Candida albicansCandida albicans
Microscopy required: oval, budding yeastMicroscopy required: oval, budding yeast Colonies <48 h old on blood-containing medium with Colonies <48 h old on blood-containing medium with
““feetfeet”” or mycelial projections or mycelial projections
*CHROMagar*CHROMagar
Abbreviated IdentificationAbbreviated Identification
Candida Candida CHROMagarCHROMagar
Abbreviated IdentificationAbbreviated Identification
Why females has higher incidence Why females has higher incidence of UTIof UTI ?? ??
Short urethraShort urethra Anus nearby urethra Anus nearby urethra contraceptivescontraceptives
Now to the labNow to the lab……