Urine Culture Urine Gram Stain Urine Culture Quantitation

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Urine Culture

Urine Culture

Urine Gram Stain

Urine Gram Stain

Urine Culture Quantitation Clean catch or catheterized urine Plate = 1000 organisms/ml Clean catch:

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

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 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

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

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

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.

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 –

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

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

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

Abbreviated Identification u Candida CHROMagar

Why females has higher incidence of UTI? ? u Short urethra u Anus nearby

Why females has higher incidence of UTI? ? u Short urethra u Anus nearby urethra u contraceptives

Now to the lab…

Now to the lab…