The epidemiology and risk factors for nosocomial catheter-associated bacteriuria caused by coagulase-negative staphylococci.

Studies of the risk factors for bacteriuria associated with the use of temporary indwelling urinary catheters have focused on gram-negative bacilli and enterococci, the predominant causes of nosocomial urinary tract infection. During a prospective study of 747 catheterized patients, bacteriuria with greater than or equal to 1,000 bacteria/mL were found in 96 patients. Coagulase-negative staphylococci (CNS) accounted for 19% of the episodes of bacteriuria, and S. epidermidis was the most frequent species of CNS. Significant risk factors for bacteriuria were a positive meatal culture for CNS, non-surgical illness, and no antibiotic therapy during catheterization. In contrast to the results of this and earlier studies that females were at greater risk factor for catheter-associated bacteriuria with gram-negative bacilli and enterococci, this was not a risk factor for acquisition of CNS. Possibly this is due to the more similar prevalence of meatal colonization with CNS of males and females compared to the striking difference in prevalence of meatal colonization with gram-negative bacilli and/or enterococci of males and females.