Antibiotic resistance and penicillin tolerance in ano-vaginal group B streptococci

O'Grady

Antimicrob Agents Chemother

2012

The objective of this study was to evaluate the rates of clindamycin and erythromycin resistance among group B Streptococcus (GBS)-positive isolates cultured from pregnant women in an upstate New York community hospital. All GBS-positive perinatal rectovaginal cultures obtained from January 2010 through October 2011 were tested for resistance to erythromycin and clindamycin. Among the 688 GBS-positive cultures, clindamycin resistance was found in 38.4% and erythromycin resistance was found in 50.7%. Rates of GBS resistance to clindamycin and erythromycin are much higher than reported in earlier U.S. studies, suggesting both increasing resistance and regional variation in resistance. These findings lend strong support to the CDC and American College of Obstetricians and Gynecologists (ACOG) recommendations that clindamycin use for intrapartum antibiotic prophylaxis be restricted to penicillin-allergic women at high risk of anaphylaxis and that GBS isolates be tested for antibiotic resistance prior to the use of clindamycin in these women. Routine screening for maternal colonization by group B Streptococcus (GBS) and intrapartum treatment of infected mothers have been a significant public health success. According to the Centers for Disease Control and Prevention (CDC), the incidence of neonatal GBS infection, a major cause of morbidity and mortality, has declined dramatically over the past 15 years, from 1.7 cases per 1,000 live births in the early 1990s to 0.34 to 0.37 cases per 1,000 live births in recent years. The most recent perinatal GBS guidelines issued by the CDC in November 2010 uphold previous antibiotic recommendations for the prophylactic treatment of GBS-colonized women during labor, except for the withdrawal of erythromycin as a second-line prophylactic antibiotic for women with penicillin allergy (6). These recommendations have also been endorsed by the American Congress of Obstetricians and Gynecologists (ACOG) in their recent committee opinion issued in April 2011 (1). According to the CDC and ACOG recommendations, clindamycin is still an acceptable alternative for women with penicillin allergy, provided that the GBS isolates have been tested for clindamycin susceptibility (1, 6). Although intrapartum antibiotic prophylactic (IAP) treatment with penicillin and ampicillin has been shown to prevent early-onset GBS disease in clinical trials, concerns have been raised regarding the ability of clindamycin, erythromycin, and vancomycin to reliably reach bactericidal levels in the amniotic fluid, fetal circulation, and fetal tissues. Additionally, according to the CDC guideline report, in vitro resistance to both clindamycin and erythromycin has been increasing, with reports published from 2006 to 2009 finding GBS resistance ranging from 25% to 32% for erythromycin and from 13% to 20% for clindamycin (6).In May 2009, Ellis Hospital, the only hospital with maternity services in Schenectady, NY, initiated testing of all GBS isolates for resistance to both erythromycin and clindamycin. This initiative wa...

Section: Discussionmentioning

confidence: 99%

Section: Discussionmentioning

confidence: 99%

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High Rates of Perinatal Group B Streptococcus Clindamycin and Erythromycin Resistance in an Upstate New York Hospital

O'Grady

Antimicrob Agents Chemother

2012

“…This method is easy and simple and could be performed in most molecular laboratories with basic equipment. Although it cannot provide information on antibiotics sensitivity, almost all GBS were sensitive to ampicillin/penicillin, making the susceptibility test probably unnecessary in clinical practice [24,25]. Extensive analysis of GBS and ST-17 clone infection using this convenient multiplex PCR method may be beneficial to pregnant women with expectant prophylactic treatment.…”

Section: Discussionmentioning

confidence: 99%

Epidemiology of Group B <b><i>Streptococcus</i></b> ST-17 Clone in Pregnant Women of South Taiwan

Hsu

Shen³

et al. 2012

Gynecol Obstet Invest

Objectives: We aimed to utilize a simple molecular assay to simultaneously detect both group B Streptococcus (GBS) and virulent ST-17 rectovaginal colonization. We also attempted to estimate the prevalence of maternal GBS and ST-17 carriers and to evaluate their seasonal association. Subjects and Methods: We used an optimized multiplex PCR method employing scp-B and ST-17 primers to analyze DNA extracted from rectovaginal swabs of 3,064 cases collected over 3 years. The incidence trends, seasonal variations, and temperature preference were analyzed. Results: The overall prevalence of maternal colonization for GBS and ST-17 clone were 13.25 and 2.48%, respectively. The ST-17 to GBS ratio was 18.72%. The occurrence of ST-17 colonization was significantly associated with seasonal variations with a preference for lower temperatures. Conclusions: We developed a novel multiplex PCR method suitable for the simultaneous detection of GBS and ST-17 clone. The phenomenon of lower temperature preference for ST-17 clone necessitates further investigation. The epidemiological data for GBS and ST-17 incidence are especially important to establish a public policy for universal GBS screening in the future.

“…Although the S. agalactiae species remains sensitive to beta-lactams, the prevalence of the resistance to clindamycin and erythromycin has increased over recent years. 33 To assess the robustness of our results, we performed a sensitivity analysis using five scenarios. Indeed, the real cost of the tests vary around the cost given by the database of the University-Hospital of Montpellier, according to the manufacturers' fees.…”

Section: Discussionmentioning

confidence: 99%

Reduction of the use of antimicrobial drugs following the rapid detection ofStreptococcus agalactiaein the vagina at delivery by real‐timePCRassay

Poncelet-Jasserand

Forges

et al. 2013

BJOG

Objective To assess whether the determination of the presence of group B streptococci (GBS) in the vagina using a rapid polymerase chain reaction (PCR) assay at delivery was able to spare useless antimicrobial treatments, as compared with conventional culture at 34-38 weeks of gestation.Design Practical evaluation and prospective cost-effectiveness analysis.Setting A university hospital in France.Population A cohort of 225 women in labour at the UniversityHospital of Saint-Etienne.Methods Each woman had a conventional culture performed at 34-38 weeks of gestation. At the beginning of labour, two vaginal swabs were sampled for rapid PCR testing and culture. The decision to prescribe a prophylactic antimicrobial treatment or not was taken according to the result of the PCR test. A comparative cost-effectiveness analysis of the two diagnostic strategies was carried out.Main outcome measures Number of women receiving inadequate prophylactic antimicrobial drugs following each testing strategy, costs of PCR testing and culture, frequency of vaginal GBS, and diagnostic performance of the PCR test at delivery. ResultsThe percentage of unnecessarily treated women was significantly reduced using the rapid test versus conventional culture (4.5 and 13.6%, respectively; P < 0.001). The rate of vaginal GBS at delivery was 12.5%. The incremental costeffectiveness ratio (ICER) for each inadequate management avoided was €36 and €173 from the point of view of the healthcare system and hospital, respectively.Conclusions The PCR assay reduced the number of inadequate antimicrobial treatments aimed to prevent the early onset of GBS disease. However, this strategy generates extra costs that must be put into balance with its clinical benefits.