Fascinoma RoundsFascinoma RoundsCoagulase negative staphylococcus in the urineCoagulase negative staphylococcus in the urine

October 26th, 2005Sharmistha Mishra,

Vanessa Allen,And with great thanks to Subash Mohan

Case 2: Coagulase negative Case 2: Coagulase negative staphylococcus in the urinestaphylococcus in the urine

• What is the clinical significance of finding CN staph in urine?

PathogensPathogens• 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 Urinary Tract Infections Caused by Coagulase-Negative Staphylococci: Coagulase-Negative Staphylococci:

Characteristics of InfectionsCharacteristics of InfectionsOrganism 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 Septicemia Associated with Staph epidermidisStaph epidermidis UTI - UTI - Case #1Case #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 Septicemia Associated with Staph Staph epidermidisepidermidis UTI - UTI - Case #2Case #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 ExplanationsPossible Explanations• Hematogenous spread of staphylococcus

epidermidis• Staphylococcus lugdunensis

– vs other CN staph species

S. lugdunensisS. 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 lugdunensisStaphylococcus lugdunensis UTIs 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 Clinical correlate of staph lugdunensis in urine culturein 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.