From the Guidelines
The presence of Staphylococcus species in a preliminary urine culture suggests a potential urinary tract infection (UTI) that requires further evaluation and possibly treatment, with the significance of Staphylococcus in urine varying based on the specific species, patient population, colony count, and clinical presentation, as noted in studies such as 1 and 1.
Key Considerations
- Initial empiric therapy with antibiotics like trimethoprim-sulfamethoxazole (160/800 mg twice daily for 3-5 days) or nitrofurantoin (100 mg four times daily for 5-7 days) may be appropriate while awaiting final culture and sensitivity results, as suggested by 1.
- Treatment decisions should be based on the colony count, patient symptoms, and final species identification, as some Staphylococcus findings may represent contamination rather than true infection, highlighting the importance of final culture results for appropriate management, as emphasized in 1 and 1.
- Staphylococcus saprophyticus is a common cause of UTIs in young, sexually active women, while Staphylococcus aureus in urine may indicate a more serious condition like bacteremia or kidney abscess, as discussed in 1 and 1.
Patient Management
- Patients should increase fluid intake, complete the full antibiotic course if prescribed, and follow up if symptoms worsen, as part of standard UTI management, as recommended by 1.
- The final culture results are crucial for appropriate management, as they guide targeted antibiotic therapy and help in distinguishing between true infection and contamination, as noted in 1, 1, and 1.
Clinical Context
- The significance of Staphylococcus in urine varies based on the specific species, patient population, colony count, and clinical presentation, making each case unique and requiring individualized assessment and management, as highlighted by the various studies including 1, 1, and 1.
From the Research
Significance of Staphylococcus sp. in Urine Culture
- Staphylococcus aureus is isolated in around 0.2%-4% of positive urinary cultures, and its presence may represent contamination, colonization, urinary tract infection, or bacteraemic seeding from another site 2.
- The isolation of Staphylococcus aureus in urine samples can be significant, as it may be associated with bacteremia, particularly in patients with certain risk factors such as indwelling urinary tract devices or prior urinary tract instrumentation 3, 4.
- Staphylococcus aureus bacteriuria may serve as a focus for subsequent bacteremia and invasive infections, and its management is crucial to prevent such complications 2, 3.
Clinical Implications
- The presence of Staphylococcus aureus in urine was accompanied by bacteremia in half of the cases, but in patients without previous urinary tract intervention, such a possibility increased to 81% 4.
- Concomitant bacteremia predicts a worse prognosis even with appropriate treatment, with an attributable mortality of 47.6% in patients with bacteremia compared to non-bacteremia 4.
- Factors associated with recurrence of Staphylococcus aureus bacteriuria include urinary catheterization, urological abnormality, diabetes, and inpatient status 2.
Management
- There is little guidance on the investigation and management of Staphylococcus aureus bacteriuria, and evidence from clinical trials is lacking 2, 3.
- A proposed algorithm to guide clinicians in the evaluation and management of patients with Staphylococcus aureus bacteriuria includes repeat urine culture and investigation and treatment of higher-risk patients, such as those prior to bladder instrumentation 2.
- Treatment options for urinary tract infections caused by Staphylococcus aureus and other multidrug-resistant organisms are available, including nitrofurantoin, fosfomycin, and carbapenems 5.