Pathophysiologic and Taxonomic Properties of Coagulase-Negative Micrococcaceae.

The purpose of this study is to determine if S. saprophyticus infections occur in South Texas, if specification of C-NS aids in recognition of such infections, and what practical methods are available for their identification. Additionally, in vitro studies were conducted to obtain a better understanding of virulence factors possibly involved in S. saprophyticus UTIs. Classification of C-NS species isolated from 289 Bexar County Hospital District clinical specimens showed that the majority of human C-NS species were present and that S. saprophyticus was a prominent pathogen in urinary infections. A patient chart review of clinically significant S. epidermidis and S. saprophyticus urine isolates revealed that S. saprophyticus was isolated predominantly from young outpatient females. Specification of C-NS was especially useful in recognizing the presence of a UTI, by documenting that a C-NS was S. saprophyticus. Antimicrobic susceptibility testing of S. epidermidis and S. saprophyticus urine isolates showed that S. saprophyticus isolates were generally more susceptible to a wider range of antimicrobics than S. epidermidis isolates. Testing C-NS isolates for susceptibility to the antibiotic novobiocin appears to be an excellent and cost-effective presumptive test for S. saprophyticus in human specimens.