ABSTRACT
The prevalence of antibiotic resistance and their genetic determinants in colonizing group B streptococci (GBS) sampled in a Swedish nationwide survey was examined. In five GBS isolates (1.3%), kanamycin/amikacin resistance and the presence of the aphA-3 gene was identified. Three of these isolates carried the aad-6 gene and were streptomycin-resistant. Screening with kanamycin and streptomycin 1,000-µg disks enabled a rapid and easy detection of these isolates. In all, 312/396 (79%) GBS were tetracycline-resistant and 95% of the examined isolates harbored the tetM gene. Among the 22 (5.5%) GBS resistant to erythromycin and/or clindamycin, the ermB gene was detected in nine isolates (41%) and erm(A/TR) in ten isolates (45%). A high level of erythromycin and clindamycin resistance with minimum inhibitory concentrations (MICs) >256 mg/L was found in four serotype V isolates that harbored ermB. The erythromycin/clindamycin resistance was distributed among all of the common serotypes Ia, Ib, II, III, IV, and V, but was not present in any of the 44 serotype III isolates associated to clonal complex 17. Screening for penicillin resistance with 1-µg oxacillin disks showed a homogenous population with a mean inhibition zone of 20 mm. A change in the present oxacillin breakpoints for GBS is suggested.
Subject(s)
Anti-Bacterial Agents/pharmacology , Carrier State/microbiology , Drug Resistance, Bacterial , Pregnancy Complications, Infectious/microbiology , Streptococcal Infections/microbiology , Streptococcus agalactiae/drug effects , Bacterial Typing Techniques , DNA, Bacterial/genetics , Female , Genes, Bacterial , Humans , Infant, Newborn , Microbial Sensitivity Tests/methods , Pregnancy , Rectum/microbiology , Serotyping , Skin/microbiology , Streptococcus agalactiae/isolation & purification , Sweden , Vagina/microbiologyABSTRACT
OBJECTIVE: To assess the impact of the indication for a previous caesarean section on the outcome of a subsequent delivery. DESIGN: Population-based cohort study. SETTING: Sweden. POPULATION: Women with two deliveries between 1987 and 2007 identified using the Swedish Medical Birth Registry. METHODS: The outcome of 69 133 pregnancies after one caesarean section was compared with the outcome of 487 610 pregnancies following one vaginal delivery. The indication for the first caesarean section was estimated using a new hierarchical system based on information from birth records. MAIN OUTCOME MEASURES: Perinatal death, low Apgar score (less than seven at 5 minutes). RESULTS: Infants of women with one previous caesarean section were at increased risk of low Apgar score compared with infants of women with one previous vaginal delivery (OR, 2.0; 95% CI, 1.9-2.1). The risk estimate was reduced when adjustment for maternal and fetal/infant characteristics was made (OR, 1.6; 95% CI, 1.5-1.8). The corresponding crude and adjusted odds ratios for perinatal death were 1.6 (95% CI, 1.4-1.7) and 1.1 (95% CI, 1.0-1.2), respectively. The infant outcome of the delivery after one caesarean section was mainly dependent on the indication for the first-delivery caesarean section and, when no medical indication was present, no increase in risk was detected. CONCLUSIONS: Infants of women with one previous caesarean section were at increased risk of low Apgar score and/or perinatal death compared with infants of women with one previous vaginal delivery. The results suggest that medical conditions, not the previous caesarean section per se, contributed to the increase in risk.
