Resistance of group B streptococcus (GBS) to antibiotics, particularly erythromycin and clindamycin, was studied. Erythromycin resistance was present in 22% of GBS isolates, and these isolates were constitutively resistant, inducibly resistant, or sensitive to clindamycin. Erythromycin and clindamycin MICs were related to the presence of ermA, ermB, or mefA genes.Group B streptococci (GBS) cause serious, life-threatening infections in the newborn. Mortality of GBS sepsis in neonates is over 50% and is particularly high in preterm infants. Maternal intrapartum prophylaxis for pregnant women colonized with GBS has been recommended for several years (1,2,4,8,9), since clinical trials showed that the administration of antibiotics to women in labor drastically reduced early-onset invasive GBS infection in the neonate.The revised Centers for Disease Control and Prevention guidelines issued in 2002 differ from previous guidelines in that universal culture-based screening for vaginal-rectal colonization with GBS is recommended for all pregnant women at 35 to 37 weeks of gestation. These guidelines recommend susceptibility testing to erythromycin and clindamycin on GBS isolates from penicillin-allergic women at risk for anaphylaxis. The goals of this study were to determine the rate of resistance to erythromycin and clindamycin in GBS colonizing pregnant women and to determine the mechanisms of antibiotic resistance present in the bacteria.Two hundred strains of GBS isolated from vaginal-rectal swabs collected between January 2002 and April 2003 from pregnant women (one isolate per patient) seen in the Family Medicine Department of a teaching community hospital were stored at Ϫ70°C until tested. A single swab was used to collect specimens from the lower vagina and rectum. Standard methods were used to isolate and identify Streptococcus agalactiae (GBS).The Kirby-Bauer disk diffusion susceptibility method was performed for penicillin, vancomycin, tetracycline, erythromycin, and clindamycin according to NCCLS guidelines (13). MICs of erythromycin and clindamycin were determined by E test for all isolates resistant or intermediate to erythromycin. The double disk diffusion test for inducible clindamycin resistance was performed on all isolates resistant to erythromycin but susceptible to clindamycin. Erythromycin and clindamycin disks were placed approximately 16 mm apart on the plate. Inducible clindamycin resistance by erythromycin was detected by a blunting of the clindamycin zone closest to the erythromycin disk, giving the appearance of a "D." Detection of the ermA, ermB, and mefA genes was done using PCR with previously published primers (6).All GBS were susceptible to penicillin and vancomycin, and 30 (15%) were susceptible to tetracycline. Resistance to erythromycin was found in 44 (22%) of the isolates.Resistance genes were detected in 100% of erythromycinresistant isolates (Table 1). Twelve isolates (6%) were resistant to both erythromycin and clindamycin. The MICs of erythromycin and clindamycin for eight of thes...

Despite its excellent antimicrobial activity against salmonellae and its favorable pharmacokinetic profile, ciprofloxacin at a dosage of 750 mg orally twice daily had an unacceptably high failure rate in patients with acute salmonellosis and may have prolonged fecal excretion of salmonellae. The late occurrence of relapses indicates the need to obtain stool cultures up to 21 days after therapy to document fecal eradication in acute salmonellosis.

The RapID Yeast Plus system (Innovative Diagnostic Systems, Norcross, Ga.) is a qualitative micromethod employing conventional tests and single-substrate chromogenic tests and having a 4-h incubation period. This system was compared with the API20C (bioMerieux Vitek, Hazelwood, Mo.) system, a 24- to 72-h carbohydrate assimilation method. One hundred thirty-three clinical yeast isolates, including 57 of Candida albicans, 26 of Candida tropicalis, 23 of Candida glabrata, and 27 of other yeasts, were tested by both methods. When discrepancies occurred, isolates were further tested by the Automated Yeast Biochemical Card (bioMerieux Vitek). Germ tube production and microscopic morphology were used as needed to definitively identify yeast isolates. The RapID Yeast Plus system correctly identified 125 yeast isolates, with an overall accuracy of 94% (125 of 133). Excellent correlation was found in the recognition of the three yeasts most commonly isolated from human sources. The test was 99% (105 of 106 isolates) accurate with C. albicans,C. tropicalis, and C. glabrata. The RapID Yeast Plus system compares favorably with the API20C system and provides a simple, accurate alternative to conventional assimilation methods for the rapid identification of the most commonly encountered isolates ofCandida species.