Urine Culture Urine Gram Stain Urine Culture Quantitation
- Slides: 15
Urine Culture
Urine Gram Stain
Urine Culture Quantitation Clean catch or catheterized urine Plate = 1000 organisms/ml Clean catch: >105 orgs/ml Suprapubic urine Any colony is significiant
Urine Cultures 1. Plates initially read at 18 -24 hr 2. All specimens plated after NOON of the previous day, hold another overnight 3. Gram positives take longer to grow
Most Common Pathogens of Human Urinary Tract u Community acquired – E. coli is most frequent pathogen isolated – Klebsiella sp and other Enterobacteriaceae – Staphylococcus saprophyticus u Hospital acquired – E. coli, Klebsiella, other Enterobacteriaceae – Pseudomonas aeruginosa – Enterococci and Staphylococci
Abbreviated Identification u E. coli – Non-swarming, spot indole pos, oxidase neg Lactose positive (Mac. Conkey or eosin methylene blue), PYR (pyrrolidonyl arylamidase) test positive 2. API 1.
Abbreviated Identification u Proteus spp. – Swarming growth – Indole u Negative: P. mirabilis/penneri – P. mirabilis: maltose neg, ornithine pos – P. penneri: maltose pos, ornithine neg u Positive: P. vulgaris
Abbreviated Identification u P. aeruginosa – Oxidase-positive bacillus – Typical smell (grapes) – Colony morphology P. aeruginosa: metallic/pearlescent, rough, pigmented, mucoid – Indole-negative
Abbreviated Identification u CHROMagar Orientation – Presumptive ID for some UTI pathogens u E. coli (dark rose to pink) u Enterococci (turquoise blue) u S. saprophyticus (light pink to rose) u S. agalactiae (light blue-green to light blue) u Proteus-Morganella-Providencia group (brown) u Klebsiella-Enterobacter-Serratia group (dark blue) – Issues and challenges u All except E. coli and enterococci require further ID – Small E. coli colonies require spot indole u Poor growth of some gram-positive bacteria u Nonselective– other pathogens may or may not produce color change
Abbreviated Identification u Enterococcus spp. – Cocci or coccobacilli in pairs and chains – >1 mm colonies – Non-hemolytic on SBA – Catalase-negative – PYR-positive (pyrrolidonyl-a-naphthylamide hydrolysis)
Abbreviated Identification u S. – – – – agalactiae (GBS) Cocci in pairs and chains Catalase-negative Narrow zone of beta-hemolysis on SBA Rapid hippurate hydrolysis test (beta strep only) OR Test for CAMP factor (spot or O/N) OR Typing by particle agglutination R/O beta hemolytic Enterococcus (PYR+) b-hem Enterococcus
Abbreviated Identification u Yeast – Candida albicans u Microscopy required: oval, budding yeast u Colonies <48 h old on blood-containing medium with “feet” or mycelial projections *CHROMagar
Abbreviated Identification u Candida CHROMagar
Why females has higher incidence of UTI? ? u Short urethra u Anus nearby urethra u contraceptives
Now to the lab…
- Gram stain vs acid fast stain
- Octet protein quantitation
- Quantitation
- Gram stain
- Gram stain mix
- O
- Gram stain techniques
- Gram stain procedure
- Corynebacterium diphtheriae gram stain morphology
- Gram stain mix
- Mannitol salt agar staphylococcus epidermidis
- Optochin test
- Serratia marcescens gram stain
- Casein hydrolysis test results
- Francisella tularensis gram stain
- Eubatteri e archeobatteri