Fascinoma Rounds Coagulase negative staphylococcus in the urine October 26th, 2005 Sharmistha Mishra, Vanessa Allen, And with great thanks to Subash Mohan

Case 2: Coagulase negative staphylococcus in the urine What is the clinical significance of finding CN staph in urine?

Pathogens Coagulase negative staphylococcus 35 spp. ~ 15 potential human pathogens Staphylococcus saprophyticus Common cause of UTI in young women Treated as outpatients Staphylococcus epidermidis Rare growth in urine Generally hospital acquired Distiguished by novobiocin in the lab

Urinary Tract Infections Caused by Coagulase-Negative Staphylococci: Characteristics of Infections Organism S. epidermidis S. saprophyticus Age and sex of affected patients Men and women equal Usually older than 50 years Women 95% 16 to 35 years old Population at risk Hospitalized patients with urinary tract complications Healthy outpatients Incidence Uncommon: 3.5% or less of all urinary tract infections in hospitalized patients Common: 20% or more of all urinary tract infections in this age group Presentation 90% asymptomatic 90% symptomatic Therapy Often resistant to multiple antibiotics Responds readily to urinary tract antimicrobials; except nalidixic acid Outcome Bacteriuria often persists after therapy Relapse rare; occasional reinfection

Septicemia Associated with Staph epidermidis UTI - Case #1 77M with DM and HTN Right hip sub-trochanteric fracture and ORIF Subsequent urinary incontinence -> indwelling Foley catheter Two weeks later he had high grade fever, confusion, and lethargy (foley had already been removed), temperature was 39.4° C , blood pressure 70/0 mm Hg, HR 126/min IV NS, ampicillin, and aztreonam and dopamine Two blood cultures = S epidermidis. Urine specimen = S epidermidis (> 106 colony-forming units/mL) Same susceptibility pattern (vancomycin, tetracycline, and trimethoprim-sulfamethoxazole). Cadorna, EA. et al, SMJ, 0038-4348, Aug 1, 1995, vol. 88, issue 8

Septicemia Associated with Staph epidermidis UTI - Case #2 64M in MVA , traumatic rupture of left hemidiaphragm Exploratory laparotomy with repair of diaphragm, left chest tube thoracostomy, and feeding jejunostomy placement 3 weeks later, pulmonary embolism -> placement of an IVC filter @ 8 weeks, the jejunostomy tube, Foley catheter, intravenous lines, and tracheostomy tube were removed. Three weeks later, his temperature rose to 39.4°C; blood pressure was 64/46 mm Hg, and the heart rate was 124/min. Two blood cultures = S epidermidis. Urine culture S epidermidis (>106 CFU/mL) with the same antimicrobial susceptibility pattern (vancomycin, tetracycline, trimethoprim-sulfamethoxazole).

Possible Explanations Hematogenous spread of staphylococcus epidermidis Staphylococcus lugdunensis vs other CN staph species

S. lugdunensis CN staph Transient skin flora, inguinal area Identified by PYR hydrolysis and ornithine decarboxylate activity More virulent than other CN staph lipase, esterase, glycocalyx and fibrinogen affinity factor Focus of infection (229) skin and soft tissue infections (7, 65) respiratory infections (13) endocarditis Bacteremia (15) brain abscess vascular prosthesis infection (11) osteomyelitis. Abscesses 14

Staphylococcus lugdunensis UTIs Generally reported as mixed flora in urine Rarely a contaminant Case #1 6F admitted with a 16 h history of fever to 39.7°C, flank pain, nausea and vomiting. WBC 18.14 A catheter specimen urinalysis showed proteinuria (1+), traces of blood and absence of nitrites microscopic analysis showed 10–20 leukocytes with a small number of bacteria. Urine culture showed growth of >100,000 colonies/ml of S. lugdunensis in a pure culture. Casanova-Roman M. et al. Scandinavian Journal of Infectious Diseases. 36(2):149-50, 2004.

Clinical correlate of staph lugdunensis in urine culture Mayo Clinic 500 isolates of coagulase-negative staphylococci from 4,652 consecutive urine specimens 31/500 (6%) staph lugdunensis 29/31 of mixed flora 70% not treated Haile Dt et al. Journal of Clinical Microbiology. 40(2):654-6, 2002 Feb.