Group B streptococcus and preventive strategies in Europe

Group B streptococcus antimicrobial resistance in neonates born to group B streptococcus-colonized mothers: Single-center survey

AIM

In this study, we collected group B streptococcus (GBS) screening data and analyzed screening rate, antimicrobial resistance rate, and neonatal observation room (NOR) admission rate due to inadequate chemoprophylaxis.

METHODS

The GBS screening data for January 2006-December 2013 were retrospectively collected and analyzed. We also collected data for neonates admitted to NOR due to inadequate chemoprophylaxis during the period 1 April 2010-31 December 2013.

RESULTS

A total of 12 200 pregnant women received rectovaginal culture during the 8-year study period. The overall screening rate was 53.8% and maternal colonization rate was 20.7%. The GBS screening rate increased remarkably, from 23.2% in 2006 to 70% in 2013. Antimicrobial resistance was common. The resistance rates for each antimicrobial used in pregnancy were as follows: clindamycin, 49.51%; erythromycin, 49.51%. A total of 297 neonates were admitted to NOR due to inadequate antibiotic prophylaxis during 1 April 2010-31 December 2013. The overall NOR admission rate due to inadequate chemoprophylaxis was 2.67%, and the inadequate chemoprophylaxis rate for those GBS colonized mothers was 19.6%. None of these 297 infants had positive blood culture for GBS sepsis.

CONCLUSION

The GBS screening rate increased remarkably, reaching 70% in 2013. The NOR admission rate due to inadequate chemoprophylaxis was 2.67% and there was no early onset GBS disease in a total of 11 123 deliveries in this 4-year cohort study.

Risk factors associated with group B streptococcus resistant to clindamycin and erythromycin in pregnant korean women

Background

The prevalence of group B streptococcus (GBS) among pregnant women and neonates in the Republic of Korea has increased. In addition, rates of resistance to antibiotics recommended for pregnant women allergic to penicillin, such as clindamycin and erythromycin, have increased. The aim of this study was to evaluate subject characteristics associated with GBS resistance to clindamycin and erythromycin.

Materials and Methods

A total of 418 clinical isolates from pregnant women in Korea were screened for antibiotic resistance from January 2006 to December 2011. Sociodemographic information, medical and obstetric history, and details of events during the previous 2 weeks were recorded using a standardized questionnaire.

Results

The resistance rates were 39.5% for clindamycin and 23.0% for erythromycin. In multiple logistic regression analysis, the subject characteristic significantly associated with resistance to both antibiotics was a history of symptomatic sore throat in the 2 weeks before obtaining the specimen (erythromycin: odds ratio [OR]: 2.13, 95% confidence interval [CI]: 1.10 to 4.13; clindamycin: OR: 2.31, 95% CI: 1.21, 4.42). Premature rupture of membranes (PROM) had an association of borderline significance.

Conclusions

In the urgent treatment of GBS-colonized pregnant women, the subject's history of previous sore throat and PROM should be considered when choosing appropriate antibiotics.

Antimicrobial resistance in colonizing group B Streptococci before the implementation of a Swedish intrapartum antibiotic prophylaxis program

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.

Group B Streptococcus early-onset disease in Emilia-romagna: review after introduction of a screening-based approach

BACKGROUND

Group B Streptococcus (GBS) is a leading cause of neonatal bacterial infections. Early-onset infections have decreased in recent years but, despite considerable efforts poured into prevention, cases continue to occur.

OBJECTIVES

To analyze trends and identify determining factors for the persistence of the GBS infections. To evaluate the impact of antenatal screening and intrapartum chemoprophylaxis on the clinical presentation of the infection.

METHODS

A prospective cohort, population-based study has been ongoing in Emilia-Romagna (Italy) since 2003. Invasive GBS infections, observed between 2003 and 2008 in infants aged < 7 days were analyzed.

RESULTS

Among 214,120 live births, 61 early-infections were observed. Fourteen infants (23.0%) were born preterm. Among 47 infants who were delivered at term, 28 were born to mothers who had no risk factors and 7 were born to mothers who had none other than GBS colonization. Forty-one women at term had been screened prenatally; among them, only 10 were documented as GBS culture-positive.Disease severity was highest in infants at lower gestational ages, but most meningitis cases were observed in term infants born to mothers who were GBS culture-negative at screening.Nine newborns had culture-proven infection despite having received intrapartum antibiotics. They were born to mothers with > or =1 obstetrical risk factors and 5 mothers had been treated during labor with macrolides.

CONCLUSION

Most infections presented in infants whose mothers had been screened as GBS culture-negative. Missed opportunities for prevention contributed more than prophylaxis failures to the early-onset disease burden.