Absence of factors associated with significant urinary tract infections caused by coagulase-negative staphylococci

Coagulase-negative staphylococci, excluding Staphylococcus saprophyticus, have recently been implicated as pathogens in urinary tract infections, especially in catheterized patients. In order to evaluate any laboratory markers for significant isolates of coagulase-negative staphylococci, we prospectively studied 72 patients with significant, indeterminant, or contaminant urine isolates of coagulase-negative staphylococci. Patients in the three categories did not differ by age, sex, presence of a urinary catheter, or other instrumentation or likelihood of nosocomial acquisition. The isolates from these three groups of patients were similar in antibiotic susceptibility and ability to produce slime. Overall, slime-producing coagulase-negative staphylococci were more likely to be S. epidermidis than any other species, but slime production was not associated with presence of pyuria, symptomatic urinary tract infection, instrumentation, nosocomial acquisition, or multiple antibiotic resistance. In this prospective study, no demographic characteristics or laboratory markers of coagulase-negative staphylococci were associated with clinical significance, as defined by symptoms or the presence of pyuria.