Amniorrhexis lowers the incidence of positive cultures for group B streptococci.

Objective: Our purpose was to determine the effect of amniorrhexis on cultures for group B streptococci.

Study Design: Intrapartum vaginal cultures for group B streptococci were obtained before and after rupture of membranes in 166 women; in addition, rectal cultures were obtained from the last 35 patients.

Results: Before rupture of membranes 49 of 166 (30%) of the vaginal cultures were positive for group B streptococci; only 28 of 166 (17%) remained positive after rupture of membranes (p = 0.

Colonization of skin and development of peritonitis due to coagulase-negative staphylococci in patients undergoing peritoneal dialysis.

Coagulase-negative staphylococci, part of the normal skin flora, frequently colonize bioprosthetic devices and are the most common cause of peritonitis in patients undergoing peritoneal dialysis. Using the API STAPH-IDENT system (Analytab Products, Plainview, New York) and plasmid pattern analysis, we investigated the importance of chronic carriage of coagulase-negative staphylococci in the development of peritonitis due to these organisms. During a nine-month period, 182 surveillance cultures of pericatheter skin and anterior nares from 30 patients yielded 102 strains of coagulase-negative staphylococci.

Reliability of in vitro susceptibility tests for detecting coagulase-negative staphylococcal resistance to penicillinase-resistant semisynthetic penicillins.

The reliabilities of five in vitro susceptibility tests (agar dilution, broth microdilution, automated MS-2, Kirby-Bauer disk diffusion, and ability to grow on methicillin-containing agar) to predict the susceptibility of 204 coagulase-negative staphylococcal isolates to penicillinase-resistant semisynthetic penicillins were compared. There was wide variation in susceptibility, with results ranging from 86.3% susceptible by MS-2 to 38.