Neonatal Group B Streptococcus Colonization Research Articles

Exploring the Feasibility of Intrapartum GBS Collection to Identify Residual GBS in a Pilot Study of an Antenatal Probiotic Intervention

(1) Background: We aimed to explore the feasibility of collecting intrapartum maternal Group B Streptococcus (GBS) colonization and immediate post-birth neonatal GBS colonization cultures for use in a larger trial and to identify cases of residual GBS, which were hypothesized to be less common in the probiotics group. (2) Methods: This sub-study added additional outcome measures to the parent study to identify intrapartum and neonatal colonization and compare between probiotic and placebo groups and to identify cases of residual GBS. Intrapartum maternal vaginal and rectal GBS cultures were collected at the time of admission to a hospital for labor and to give birth. Neonatal oral and nasopharynx GBS cultures were collected within 1–2 h of giving birth. (3) Results: Thirty intrapartum samples were collected; twenty-eight had complete data. The antepartum GBS results significantly predicted the intrapartum results (p = 0.005), with 86.7% of cultures remaining the same at both time points. There were four cases where the intrapartum GBS results were different to the 36-week antepartum cultures results. A case of residual GBS was identified in one probiotic group participant. None of the neonatal swabs were positive for GBS. No cases of EOGBSD occurred in infants born to the study participants. (4) Conclusions: Although the 36–37 week GBS results significantly predicted the intrapartum results, the utility for a larger research trial on probiotics to reduce antenatal GBS is unclear. Intrapartum GBS swab collection was feasible in a busy nurse, midwife, and physician practice. GBS was not recovered from neonatal oral and nasopharyngeal swabs. The pathways of neonatal GBS colonization require further study.

Vertical Transmission, Risk Factors, and Antimicrobial Resistance Patterns of Group B Streptococcus among Mothers and Their Neonates in Southern Ethiopia.

Background Group B Streptococcus (GBS) contributes to maternal and neonatal morbidity and mortality by increasing intrauterine infection or vertical transmission at the time of birth. Despite many efforts to reduce the potential risk of vertical transmission, GBS remains the main cause of serious disease (neonatal sepsis, meningitis, and/or pneumonia) in vulnerable newborns during the first week of life. This study aimed to assess vertical transmission, risk factors, and antimicrobial resistance patterns of GBS among pregnant women and their neonates. Methods A facility-based cross-sectional study was conducted among mothers and their neonates from February to May 2021. A total of 201 pregnant women with their neonates participated in this study. A well-designed questionnaire was used to collect sociodemographic and clinical data. A vaginal swab from mother before delivery and neonatal nasal and ear canal swab samples were taken as soon as after delivery within 30 minutes. Vaginal swabs, neonatal ear canal, and nasal swabs were placed into Todd–Hewitt broth and incubated at 37°C for 18–24 hours at 35–37°C in 5% CO2 conditions and then subcultured on 5% sheep blood agar for 18–48 hours. Presumptive identification of GBS was made by morphology, Gram stain, catalase, and hemolytic activity on sheep blood agar plates. CAMP and bacitracin susceptibility tests were used as confirmatory tests for GBS. Data were analyzed using SPSS version 21. P value ≤0.05 was considered statistically significant. Results Vertical transmission rates of GBS (mother to neonates) were 11.9%. The prevalence of GBS among pregnant women and newborns was 24/201 (11.9%) (95% CI = 7.5–16.9) and 11/201 (5.5%) (95% CI = 2.5–9.0), respectively. The history of prolonged rupture of membranes (AOR = 3.5, CI = 2.2–18.8) and urinary tract infection (AOR = 2.9, CI = 1.7–16.3) were associated factors for maternal GBS colonization. Gestational age of <37 weeks (p=0.008), low birth weight of <2.5 kg (p=0.001), and maternal history of vaginal discharge (p=0.048) were associated factors for neonatal GBS colonization. Low antibiotic resistance was observed for erythromycin 8.6%, clindamycin 5.7%, and chloramphenicol 2.9%. Conclusion In this study, high vertical transmission (mother to neonates) rate was observed. The prevalence of vaginal GBS colonization of women at delivery was 11.9% and significantly associated with the history of prolonged rupture of membranes and urinary tract infections. Gestational age of <37 weeks, low birth weight of <2.5 kg, and maternal history of vaginal discharge were associated with neonatal GBS colonization. Hence, there is a need for antenatal culture-based GBS screening, risk factor-based interventions, and regular follow-up of drug resistance patterns for proper treatment and management of GBS.

Association of Obesity With Maternal and Cord Blood Penicillin Levels in Women With Group B Streptococcus Colonization.

To compare maternal and cord blood penicillin concentrations in women with and without obesity who are receiving intrapartum group B streptococcus (GBS) prophylaxis. We performed a prospective cohort study of term women receiving intrapartum penicillin prophylaxis for GBS colonization (determined by antenatal rectovaginal culture). The following outcomes were compared between obese (body mass index [BMI] 35 or higher at delivery) and nonobese (BMI less than 30 at delivery) groups: penicillin concentration in maternal blood (after two penicillin doses) and umbilical cord blood, GBS rectovaginal colonization status on admission and after two completed doses, and neonatal GBS colonization (using a postnatal ear swab). Fifty-five women were needed to detect a 0.75 SD difference in cord blood penicillin concentrations. Fifty-five women were enrolled and had all specimens collected; 49 had complete data for analysis (obese n=25, nonobese n=24). There was no difference in the median maternal penicillin concentration between groups (obese 4.2 micrograms/mL vs nonobese 4.0 micrograms/mL, P=.58). There was, however, a 60% lower median cord blood penicillin concentration in the obese compared with the nonobese group (2.7 micrograms/mL vs 6.7 micrograms/mL, respectively, P<.01), with no significant difference in time from last penicillin dose to delivery (obese 2.9 hours vs nonobese 1.7 hours, P=.07). The difference in cord blood concentrations remained significant after adjustment for nulliparity, hypertensive disorders, and time from last penicillin dose to delivery. Only 59.6% of women tested positive for GBS by rectovaginal culture on admission (obese 60.9% vs nonobese 58.3%, P=.86). The median cord blood penicillin concentration was 60% lower in neonates born to women with obesity compared with those born to women without obesity. However, all concentrations exceeded the minimum inhibitory concentration. Maternal penicillin levels were not significantly different between groups. More than 40% of women who previously tested positive for GBS by antenatal culture tested negative for GBS on admission for delivery.

Group B streptococcal transmission rates as determined by PCR.

Background Group B Streptococcus (GBS) is a common cause of neonatal sepsis. GBS colonization of the newborn gastrointestinal tract (GIT) may be a critical precursor for late-onset infection. Assessment of the rate of neonatal GBS intestinal colonization has generally relied upon culture-based methods. We used polymerase chain reaction (PCR) and culture to determine the rate of GBS transmission to neonates. We hypothesized that PCR may enhance the detection of neonatal GBS colonization of the GIT, and that the rate will be higher when evaluated with PCR as compared to culture. Methods This was a cross-sectional study, in which mothers who were positive for GBS on routine screening and their healthy infants were eligible for recruitment. Newborn stool was collected after 24 h of life and before hospital discharge, and stored at -80°C for culture and PCR targeting the GBS-specific surface immunogenic protein (sip) gene. Results A total of 94 mother-infant pairs were enrolled; of these pairs, stool was collected from 83 infants. Based on PCR, the overall GBS transmission rate was 3.6% (3/83). The transmission rate was 2.4% (1/41) among vaginal deliveries and 4.8% (2/42) among cesarean deliveries. The results of culture-based transmission detection were identical. Conclusion These results indicate that the rate of GBS transmission is low and that detection may not be enhanced by PCR methods.

Risk factors for neonatal group B streptococcus vertical transmission: a prospective cohort study of 1815 mother-baby pairs.

The potential factors associated with group B streptococcus (GBS) vertical transmission have not been studied in detail. A prospective cohort study was conducted to recruit 1815 mother-neonate pairs for GBS analysis. Pearson's chi-squared tests and generalized linear models were used to explore the risk factors for neonatal GBS colonization. The rate of GBS vertical transmission was 14.1%. GBS colonization in all neonates was significantly associated with maternal GBS colonization, mode of delivery, episiotomy, number of prenatal vaginal exams, parity, and hypertension. For neonates born to GBS-positive mothers, GBS vertical transmission was associated with the mode of delivery, episiotomy, and sexually transmitted diseases. For neonates born to GBS-negative mothers, neonatal GBS colonization was associated with the number of prenatal vaginal exams, parity, and hypertension. These findings suggest the need for prenatal GBS screening for pregnant women and intrapartum antimicrobial prophylaxis for GBS-colonized women.

Molecular Epidemiological Status of Group B Streptococcus in Ile Ife South Western Nigeria

Studies in some sub-Saharan African countries like Zimbabwe, Malawi, Kenya and Gambia revealed that Group B Streptococcus (GBS) is emerging as the main cause of neonatal sepsis and meningitis. However, in Nigeria, information on GBS disease prevalence remains sparse. We sourced to isolate GBS from the rectovaginal and neonatal samples that were obtained from a tertiary hospital in a populated area of Osun state and give an updated information on the antibiotic susceptibility patterns, using demographic and clinical parameters. 170 samples were collected from consenting mothers and neonate from June, 2016 to January 2017. Ninety-Eight (98) GBS isolates were recovered from vaginal, rectal of the pregnant woman at the point of labour and Umbilical cord of the neonate within 24 h of birth. Cultures for the isolation and identification of Group B Streptococcus (GBS) were carried out using the CDC recommended microbiological methods. The Kirby-Bauer disk-diffusion method was mployed to determine antibiograms of GBS isolates in accordance with Clinical and Laboratory Standards institute (CLSI). The presence of resistant genes was examined using PCR. The prevalence rate of GBS maternal and neonatal colonization were 29.4% and 20.6% respectively while 4% of the colonized neonates had nosocomial GBS colonization. There was no significant association between GBS colonization status and age (p>0.05), parity (p>0.05), obstetric risk factors (p>0.05) and sex of neonate. One out of the 8 representatives of the multidrug resistant isolates harboured tetM gene while other resistant genes examined were negative in all MDR isolates. High prevalence of maternal and neonatal GBS colonization has been established among pregnant women and neonates in the study area. Nosocomial infection was implicated in GBS colonization among neonates. However further research is called for using larger sample size and multiple curve studies for adequate extrapolation into the general population.

Antibiotic Prevention for Maternal Group B Streptococcal Colonization on Neonatal GBS-Related Adverse Outcomes: A Meta-Analysis.

Maternal colonization with group B Streptococcus (GBS) during pregnancy increases the risk of neonatal infection by vertical transmission. However, it remains unclear whether treating all colonized women during labor exposes a large number of their neonates to possible adverse effects without benefit. We performed a meta-analysis to assess the effect of intrapartum antibiotic prophylaxis on neonatal adverse outcomes. We identified studies by searching several English and Chinese electronic databases and reviewing relevant articles. Data were pooled using fixed-effects or random-effects meta-analysis, and for each outcome both risk ratio (RR) and 95% confidence intervals (95% CIs) were calculated. Fourteen studies (2,051 pregnant women and 2,063 neonates) were included, comprising 13 randomized clinical trials and 1 cohort study. Antibiotic prophylaxis is associated with a significant reduced risk of all cause infections (RR = 0.28, 95% CI = 0.18–0.42), GBS infection (RR = 0.24, 95% CI = 0.13–0.44), early-onset GBS infection (RR = 0.24, 95% CI = 0.13–0.45), non-GBS infections (RR = 0.34, 95% CI = 0.20–0.59), and GBS colonization (RR = 0.10, 95% CI = 0.06–0.16). But no significant reduction was observed in late-onset GBS infection, mortality from early-onset GBS infection or from non-GBS infections. Notably, no significant differences were found between ampicillin and penicillin prevention for neonatal adverse outcomes. Our findings suggest that antibiotic prophylaxis is effective in reducing neonatal GBS colonization and infection.

Group B streptococcus and Escherichia coli colonization in pregnant women and neonates in Lithuania

ObjectiveTo evaluate the prevalence of maternal and neonatal colonization with group B streptococcus (GBS) and Escherichia coli, and examine GBS serotypes and susceptibility to antibiotics. MethodsA prospective cross-sectional study was carried out in Lithuania between October 2006 and June 2007. Lower vaginal/rectal swabs were obtained from pregnant women (n=998) and ear canal/throat swabs were obtained from their newborns (n=827) for culture. ResultsOverall, maternal and neonatal GBS colonization rates were 15.3% and 6.4%, respectively. Serotypes III (34.5%) and Ia (29.7%) were most common. All GBS isolates were susceptible to penicillin and 4.1% were resistant to erythromycin. Overall, maternal and neonatal E. coli colonization rates were 19.9% and 14.4%, respectively. In total, 71.4% of newborns with E. coli colonization were born to E. coli-negative mothers. E. coli was resistant to ampicillin and piperacillin in 25.9% and 16.6% of cases, respectively. The majority of E. coli-colonized newborns were contaminated with maternal fecal, but not vaginal, E. coli strains. ConclusionMaternal and neonatal GBS colonization rates, serotypes, and susceptibility to antibiotics were comparable to those reported in previous studies. Population-based data regarding early-onset neonatal infection rates will enable the formulation of a prevention program for early-onset GBS disease in Lithuania.

Efficacy of intrapartum chemoprophylaxis less than 4 hours duration

Objective. Current guidelines for prevention of group B streptococcus (GBS) early-onset infection recommend to administer antibiotic during labor at least 4 h prior to delivery (adequate prophylaxis). We aimed to determine if neonatal GBS colonization may be significantly decreased in case of inadequate (<4 h) duration of ampicillin prophylaxis.Methods. In prospective, cohort study, 167 infants born to 167 GBS culture-positive mothers without additional risk factors were enrolled. Cultures were collected both, at 10–24 h after birth (admission) and at discharge.Results. Among 137 infants born to mothers who received inadequate prophylaxis, 5 (3.6%, C.I. = 0.5–6.8) were colonized (≥1 sites) at admission, at discharge, or both, at admission and discharge. Eighty-two women received prophylaxis <2 h before delivery and two infants (2.4%) were colonized at discharge.Eighteen (60.0%, C.I. = 42.5–77.5) of 30 infants who were not exposed to prophylaxis were colonized at admission or both, at admission and discharge.Colonization was significantly more frequent among infants born to untreated mothers with respect to infants born to women who received inadequate prophylaxis (either <2 or <4 h).Conclusions. In this selected group, inadequate prophylaxis significantly interrupted vertical colonization. This effect was evident even if prophylaxis started <2 h before delivery.

Colonização materna e neonatal por estreptococo do grupo B em situações de ruptura pré-termo de membranas e no trabalho de parto prematuro

To identify the prevalence and risk factors of maternal colonization by group B streptococcus (GBS) in pregnant women with premature labor (PL) and/or premature membrane rupture (PMR). Two anal and two vaginal swabs were collected from 203 pregnant women with diagnosis of PL or PMR assisted at the practice along one year. Pregnant women with imminent labor at admission were excluded. One swab of each source was placed in a transfer milieu and sent for culture in blood-agar plates; the two remaining swabs were incubated for 24 hours in Todd-Hewitt milieu for further sowing in blood-agar plates. Risk factors were analyzed by the chi-square test, Student's t-test (p-value set at 0.05 and 95% confidence interval) and logistic regression. The following variables were analyzed: age, race, parity and mother schooling; culture results by source and type of culture; admission diagnosis; gestational age at admission; asymptomatic bacteriuria; gestational age at delivery; type of delivery; neonatal GBS colonization rate and immediate neonatal condition. Prevalence of maternal GBS colonization was 27.6% (56 cases). The colonization rates according to gestational complications were 30% for PMR, 25.2% for PL and 17.8% for PL + PMR. Univariate analysis has shown that the variables Caucasian race, low level of schooling and bacteriuria were associated with higher colonization rates. Multivariate analysis showed that the presence of urinary infection was the only variable associated with maternal colonization. The GBS detection rate was significantly higher with the use of a selective milieu and collection from both anal and vaginal sources. The neonatal colonization rate was 3.1%. Two cases of early sepsis by GBS occurred in the sample, with prevalence of 10.8 cases per one thousand live births and 50% mortality rate. The studied sample showed high maternal colonization rates by Streptococcus agalactiae. To increase GBS detection rate, it is necessary to use a selective culture milieu and to combine anal-rectal and vaginal cultures. There was a high incidence of early neonatal sepsis.

Group B streptococcus colonization of Greek pregnant women and neonates: prevalence, risk factors and serotypes

To evaluate the prevalence and risk factors of group B streptococcus (GBS) colonization among pregnant women and their neonates in Greece, and to examine the serotype distribution of the GBS strains isolated and their susceptibility to antibiotics. A vaginal and a rectal swab were obtained from 1014 pregnant or parturient women followed at public and private hospitals in Athens and in a city of northern Greece. Cultures were also taken 24 h after birth from 428 neonates born to these women. The overall maternal and neonatal colonization rates were 6.6% and 2.4%, respectively. The vertical transmission rate was 22.5%. By logistic regression analysis, multiparity (>/=III) was associated with a lower colonization rate (odds ratio 4.4, 95% confidence interval 1.08-18.63). In contrast with other studies, middle-class women followed privately were more frequently colonized (10%) than those followed at the public hospital (3.9%) (odds ratio 3.1, 95% confidence interval 1.83-5.42). A higher number of prenatal visits was also associated with a higher colonization rate (change in true odds ratio when visits increased by one, 1.3; 95% confidence interval 1.14-1.60). No association was found between colonization and maternal age, previous obstetric history, marital status, nationality, prematurity, Caesarean section, or infant birth weight. The most common serotypes were II (26.9%), III (22.4%), Ia (19%), Ib (12%), and V (9%). A considerable proportion of the isolated strains was resistant to erythromycin (4.5%), clindamycin (6%), or both (6%). The rate and risk factors of maternal and neonatal GBS colonization may vary in different communities. These rates, as well as the incidence of neonatal disease, need to be thoroughly evaluated in each country to allow the most appropriate preventive strategy to be selected.