Group B Streptococcus In Pregnant Women Research Articles

SURVEY ON THE SITUATION OF GROUP B STREPTOCOCCUS INFECTION IN PREGNANT WOMEN OVER 35 WEEKS AT MEDLATEC GENERAL HOSPITAL

Group B Streptococcus (GBS) is still considered as leading cause of early neonatal infections. Vertical transmission from mother to child may occur when a pregnant woman was infected with GBS in vaginal - rectum at the time of labor or the water breaks of delivery. Therefore, early screening for GBS in pregnant women over 35 weeks is essential to prevent neonatal infection due to GBS.Objectives: 1) Determine the prevalence of GBS exposure in the vaginal rectum of pregnant women over 35 weeks using cultural and Realtime PCR techniques. 2) Evaluation of the sensitivity of the isolated GBS to antibiotics.Subjects and methods: Prospective study in 243 pregnant women over 35 weeks who visited and/or had a culture test for Group B Streptococcus at Medlatec General Hospital. Samples of vaginal - rectum fluid were paralelly tested by 2 methods of culture and Realtime PCR. GBS-isolated strains were tested for their susceptibility to antibiotics. 
 Results: The rate of GBS infection in pregnant women over 35 weeks by culture method is 16.9%, Realtime PCR is 18.9%. The rate of group B Streptococcus sensitive to ampicillin, ceftriaxone, cefotaxime, vancomycin, linezolid are 100%; with levofloxacin at 95.0%, erythromycin at 29.0% and clindamycin at 25.0%.Conclusions: The rate of Group B Streptococcus infection in pregnant women over 35 weeks as determined by culture method (16.9%), is lower than Realtime PCR (18.9%). Group B Streptococcus is sensitive to most of the first-line antibiotics such as penicillin, ampicillin, ceftriaxone, cefotaxime and is high resistance to erythromycin (68.4%) and clindamycin (72.5%).

Distribution and Prevalence of Serotypes of Group B Streptococcus Isolated from Pregnant Women in 30 Countries: A Systematic Review

Abstract Objective This review aimed to compile scientific data on the distribution and prevalence of group B Streptococcus (GBS) serotypes isolated from pregnant women across 30 countries from 2010 to 2019. Methods This was a systematic review that addresses the distribution and prevalence of GBS in pregnant women. The search included studies published between January 2010 and December 2019 in PubMed, Virtual Health Library (BVS), ScienceDirect, Scientific Electronic Library Online (SciELO), and LILACS databases. We also surveyed relevant articles published in English, Spanish, and Portuguese between February and April 2020. Original articles, communication, short report, theses, and dissertations were included. The prevalence of GBS colonization, method for capsular serotyping, antimicrobial resistance, distribution and prevalence of serotypes were extracted from each study. Results In all, 795 publications were identified. After applying the eligibility criteria, 48 articles were included for the final systematic analysis; most articles were from Asia and were published during the years 2014 to 2017. For the identification of serotypes, most studies used the polymerase chain reaction technique. There were records of all 10 GBS serotypes, namely, Ia, Ib, and II–IX, among the countries analyzed. GBS susceptibility and resistance to antibiotics were addressed in 37.5% of the publications analysed. Conclusion This review showed that GBS serotypes are distributed differently in the 30 analyzed countries, with serotypes Ia, Ib, and II to V being the most prevalent. Furthermore, our results highlighted the relationship of GBS with maternal colonization, implications for neonates, and antibiotic resistance.

CRISPR/Cas12a-based assay for the rapid and high-sensitivity detection of Streptococcus agalactiae colonization in pregnant women with premature rupture of membrane

BackgroundStreptococcus agalactiae or group B Streptococcus (GBS) is a leading infectious cause of neonatal morbidity and mortality. It is essential to establish a robust method for the rapid and ultra-sensitive detection of GBS in pregnant women with premature rupture of membrane (PROM).MethodsThis study developed a CRISPR-GBS assay that combined the advantages of the recombinase polymerase amplification (RPA) and CRISPR/Cas12a system for GBS detection. The clinical performance of the CRISPR-GBS assay was assessed using vaginal or cervical swabs that were collected from 179 pregnant women with PROM, compared in parallel to culture-based matrix-assisted laser desorption ionization time-of-flight mass spectrometry (culture-MS) method and real-time quantitative polymerase chain reaction (qPCR) assay.ResultsThe CRISPR-GBS assay can be completed within 35 min and the limit of detection was as low as 5 copies μL−1. Compared with the culture-MS, the CRISPR-GBS assay demonstrated a sensitivity of 96.64% (144/149, 95% confidence interval [CI] 92.39–98.56%) and a specificity of 100% (30/30, 95% CI 88.65–100%). It also had a high concordance rate of 98.88% with the qPCR assay.ConclusionsThe established CRISPR-GBS platform can detect GBS in a rapid, accurate, easy-to-operate, and cost-efficient manner. It offered a promising tool for the intrapartum screening of GBS colonization.

Vaginal Carriage of Group B Streptococcus (GBS) in Pregnant Women, Antibiotic Sensitivity and Associated Risk Factors in Dakar, Senegal.

The eradication of neonatal Group B Streptococcus (GBS) infections, considered as a major public health priority, necessarily requires a mastery of the data on vaginal carriage in pregnant women. The aims of this study were to determine the prevalence of vaginal carriage of GBS in pregnant women, antibiotic susceptibility, and associated risk factors. This was a cross-sectional, descriptive study conducted over a period of 9 months (July 2020 to March 2021) in pregnant women between 34 and 38 weeks of gestation (WG) followed at the Nabil Choucair health center in Dakar. Identification and antibiotic susceptibility of GBS isolates were performed on the Vitek 2 from vaginal swabs cultured on Granada medium. Demographic and obstetric interview data were collected and analyzed on SPSS (version 25). The level of significance for all statistical tests was set at P < .05. The search of GBS vaginal carriage had involved 279 women aged 16 to 46 years, with a median pregnancy age of 34 (34-37) weeks' gestation. GBS was found in 43 women, for a vaginal carriage rate of 15.4%. In 27.9% (12/43) of volunteers screened, this carriage was monomicrobial, while in 72.1% (31/43) of women, GBS was associated with other pathogens such as Candida spp. (60.5%), Trichomonas vaginalis (2.3%), Gardnerella vaginalis (34.9%) and/or Mobiluncus spp. (11.6%). The level of resistance was 27.9% (12/43) for penicillin G, 53.5% (23/43) for erythromycin, 25.6% (11/43) for clindamycin and 100% for tetracycline. However, the strains had retained fully susceptible to vancomycin and teicoplanin. The main risk factor associated with maternal GBS carriage were ectocervical inflammation associated with contact bleeding (OR = 3.55; P = .005). The high rate of maternal vaginal GBS carriage and the levels of resistance to the various antibiotics tested confirm the importance of continuous GBS surveillance in our resource-limited countries.

Use of Recombinant Endolysin to Improve Accuracy of Group B Streptococcus Tests.

ABSTRACTGroup B Streptococcus (GBS) causes serious neonatal infection via vertical transmission. The prenatal GBS screening test is performed at the late stage of pregnancy to avoid risks of infection. In this test, enrichment culture is performed, followed by GBS identification. Selective medium is used for the enrichment; however, Enterococcus faecalis, which is a potential contaminant in swab samples, can interfere with the growth of GBS. Such bacterial contamination can lead to false-negative results. Endolysin, a bacteriophage-derived enzyme, degrades peptidoglycan in the bacterial cell wall; it is a promising antimicrobial agent for selectively eliminating specific bacterial genera/species. In this study, we used the recombinant endolysin EG-LYS, which is specific to E. faecalis; the endolysin potentially enriched GBS in the selective culture. First, in the false-negative model (coculture of GBS and E. faecalis, which disabled GBS detection in the subsequent GBS identification test), EG-LYS treatment at 0.1 mg/ml improved GBS detection. Next, we used 548 vaginal swabs to test the efficacy of EG-LYS treatment in improving GBS detection. EG-LYS treatment (0.1 mg/ml) increased the GBS-positive ratio to 17.9%, compared to 15.7% in the control (phosphate-buffered saline [PBS] treatment). In addition, there were an increased number of GBS colonies under EG-LYS treatment in some samples. The results were supported by the microbiota analysis of the enriched cultures. In conclusion, EG-LYS treatment of the enrichment culture potentially improves the accuracy of the prenatal GBS screening test.IMPORTANCE Endolysin is a bacteriophage-derived enzyme that degrades the peptidoglycan in the cell wall of host bacteria; it could be used as an antimicrobial agent for selectively eliminating specific bacterial genera/species. Group B Streptococcus (GBS) causes neonatal infection via vertical transmission; prenatal GBS screening test, in which enrichment culture is followed by bacterial identification, is used to detect the presence of GBS in pregnant women. However, the presence of commensal bacteria such as Enterococcus faecalis in clinical specimens can inhibit GBS growth in the selective enrichment culture, resulting in false-negative result. Here, we demonstrated that the application of originally isolated endolysin in the enrichment culture improved the test accuracy by inhibiting unwanted E. faecalis growth and therefore avoiding false-negative results, not only in experimental settings, but also in tests using vaginal swabs.

Prevalence and molecular characterization of group B streptococcus in pregnant women from hospitals in Ohangwena and Oshikoto regions of Namibia

BackgroundThe main purpose of this study was to investigate the prevalence rate, antimicrobial susceptibility patterns and molecular characteristics of Streptococcus agalactiae isolated from pregnant women at 35 weeks of gestation and above, who attended antenatal screening at selected hospitals in Ohangwena and Oshikoto regions of Namibia.ResultsOut of 210 women screened for Group B Streptococcus (GBS), 12 (5.7%) were colonised of which 25.0% were colonised rectovaginally, 58.0% vaginally and 17.0% rectally. No significant association was reported between GBS colonisation and maternal age, geographic location, marital status, education, employment, parity, still births and miscarriages (P values > 0.05). Antimicrobial susceptibility was reported at 100% for ampicillin, penicillin & ceftriaxone which are commonly used for empiric treatment of infection with GBS. Resistance to tetracycline was reported at 100%. Tetracycline resistance gene tet(M) was present in 88.9% of the isolates only and none of the isolates presented with tet(O). Polysaccharide capsular type Ia was found in 9(50%) and Ib was found in 1(5.5%) of the total isolates. The remaining isolates were not typeable using PCR.ConclusionStreptococcus agalactiae’s positive rate was 5.7% among the pregnant women examined. Socio-demographic and obstetric factors had no influence on GBS colonisation (P values > 0.05). No resistance was reported to ampicillin, penicillin and ceftriaxone. No sensitivity was reported to tetracycline. Fifty percent of the isolates were capsular type Ia, 5.5% were type Ib and 44.4% were not typeable using PCR. The study provides crucial information for informing policy in screening of GBS in pregnant women.

Molecular Characterization of Streptococcus agalactiae Isolates from Pregnant Women in Kathmandu City.

Introduction Group B streptococci (GBS) are globally recognized as one of the leading causes of neonatal sepsis and meningitis and is also known to cause adverse pregnancy outcomes such as stillbirths and miscarriages. Thus, detailed investigation of GBS in pregnant women has special significance in public health related researches. Objectives The present study is aimed at evaluating the prevalence of GBS colonization among pregnant women in Kathmandu city. Methods The study was carried out among 125 pregnant women at their trimester (35–37 weeks) (during the time period between January and June in 2018). The prevalence was determined by the culture method in HiCrome Strep B Selective Agar Base and then by using the PCR technique. The serotypes were evaluated by multiplex PCR analysis, while the antibiotics susceptibility tests were performed using the disk diffusion method. Results Among 125 samples studied, GBS were recorded in 24 samples (implying a prevalence of 19.2%). Furthermore, using the multiplex PCR, among 24 GBS-positive samples, 13 (54.17%) were found to be typeable while 11 (45.83%) were nontypeable. The most abundant serotype recorded in this study was type III (33.33) while the serotypes IV, V, VI, VII, and VIII were not found. Conclusion The isolates were sensitive towards some antibiotics such as linezolid and ceftriaxone 100%, whereas penicillin 50% and vancomycin 75% but were resistant to tetracycline and ertapenem. Serotype III was found to be predominant in the samples collected during the study period. The observed prevalence was significantly associated with the gestational period, whereas no relationship was found for other risk factors.

Group B Streptococcus in Indian Pregnant Women: Its Prevalence and Risk Factors

AbstractPurpose: To study the prevalence of group B streptococci (GBS) in Indian pregnant women and associated risk factors. Methods: Four hundred and fifty pregnant women attending antenatal outpatient/inpatient department between 35-38 weeks of gestation were enrolled in the study. All enrolled subjects were assessed by a predefined proforma for their demographics, socio-economic characteristics, education, toilet habits, obstetric history and clinical outcome. Two cotton swabs each from lower vagina and rectum were collected and plated on selective solid media CHROM agar Strept B (CHROMagarTM) and selective Enrichment Broth LIM RambaQUICK StreptB broth (CHROMagarTM). Presumptive identification of GBS was growth of 1-3 mm grayish white β-hemolytic colonies on BAP or mauve coloured colonies on CHROM agar Strept B. All presumptively identified GBS were confirmed as group B streptococcus by automated identification system-Vitek MS (Bio Merieux). Results: The recto vaginal colonization rate of GBS in this study was observed as 3.3% (n=15). GBS colonization was significantly associated with nulliparous women (p= 0.026) and use of western style toilet (p=0.017). GBS urinary tract infections was also seen more commonly in women with GBS rectovaginal colonization (p=0.002). Conclusion: Due to the low GBS prevalence and no significant association with major risk factors, we recommend to institute universal screening of GBS in pregnant women, instead of risk based screening. Since this was a single centric study with low prevalence of GBS, its applicability may be limited, therefore further larger multi-centric prospective studies are required to understand the true GBS prevalence in Indian society.

Analysis of screening strategy of group B streptococcus in the third trimester and its influence on pregnancy outcome

Objective: To investigate the screening strategy of group B streptococcus (GBS) in the reproductive tract of women in the third trimester and analyze its impact on pregnancy outcome. Methods: A total of 85 461 pregnant women in 35-37 weeks of gestation from Bao'an Maternity and Child Health Hospital, Jinan University from January 2011 to June 2018 were enrolled. They were divided into 3 periods according to different GBS screening strategies, the unscreened period included 31 384 cases (36.72%), 33 267 cases (38.93%) were included in partial screening period, 20 810 cases (24.35%) were included in screening period. All GBS screening positive pregnant women were given intrapartum antibiotic prophylaxis (IAP). The impact on pregnancy outcomes, and the impact of different GBS collection transport and culture methods on the positive rate of GBS screening were analyzed. Results: (1) The incidence of neonatal early onset GBS disease (EOGBSD) in unscreened period was 0.03% (11/31 773), in partial screening period was 0.02%(6/33 887), and in screening period, the incidence of neonatal EOGBSD decreased to 0, the difference was statistically significant (χ(2)=7.86, P=0.02).(2) The incidence of hematogenous infection of GBS in pregnant women was 0.02%(6/33 887) in partial screening period, and there was none in screening period, there was no significant difference (adjusted χ(2)=3.75, P=0.05). (3) In the screening period, the positive rate of GBS was 14.08%(2 719/19 306), which was significantly higher than the positive rate of GBS in the partial screening period (11.48%, 2 058/17 920; χ(2)=56.12, P=0.00). (4) Antibiotic sensitivity tests of 4 777 GBS strains showed that the antibiotics with higher resistance rate were tetracycline (81.52%, 3 896/4 777), erythromycin (66.59%, 3 181/4 777), and clindamycin (64.31%, 3 072/4 777). The combination of erythromycin, clindamycin and tetracycline was the most common resistant pattern, accounting for 48.80% (2 331/4 777). No penicillin, ceftriaxone or vancomycin resistant strains was found. Conclusions: GBS screening strategy in different regions could combine the local neonatal EOGBSD incidence rate, maternal GBS colonization rate, and the socioeconomic factors to determine whether universal GBS screening or screening for high-risk maternal women. GBS screening positive rate is related to the population, scope of the investigation, the sample collection, delivery and culture methods. The multi-drug resistance rate of GBS is high.

Detection and genomic analysis of genital group B streptococcus in pregnant Korean women.

Group B streptococcus (GBS) is a leading cause of life-threatening bacterial infections among newborns, and neonates born to heavily colonized women may be subject to vertical transmission. We sought to determine an appropriate detection method for genital GBS in pregnant women by comparing culture-based methods and real-time polymerase chain reaction (PCR). In addition, we performed molecular serotyping and multilocus sequence typing (MLST) on isolates. A total of 150 pregnant women were enrolled and underwent vaginal-rectal swabbing at 16-40 weeks of gestation. GBS was identified by conventional culture and real-time PCR with or without enrichment. Molecular serotyping and MLST were performed on isolates. Overall genital GBS positive rate among the 150 study subjects was 17.3%. Direct culture identified 18 (12.0%) positive specimens, enrichment culture 22 (14.6%), direct PCR 24 (16.0%) and enrichment PCR 25 (16.6%). The sensitivity and specificity by direct and enrichment PCR were as follows: for direct PCR, 90.9% and 96.9%, respectively; and for enrichment PCR, 95.5% and 96.9%, respectively. Resistance rates to clindamycin and erythromycin were 33.3% and 19.1%, respectively. Serotype III-1 was the most common (26.3%), followed by serotype Ib (21.1%), III-3 (15.8%), V (15.8%), II (10.5%), IV (5.3%) and VI (5.3%). Most common sequence types (ST) were ST-1, ST-19 and ST-862 (15.8%), followed by ST-2 and ST-654 (10.5%). Direct real-time PCR using vaginal-rectal specimen could be used for detecting GBS in emergent conditions. Molecular serotypes III, Ib and V were most common. MLST analysis frequently presented ST-1, ST-19 and ST-862.

Detection of group B Streptococcus (GBS) in pregnant women by SYBR Green real-time PCR

Objectives: Application of SYBR Green real-time PCR and bacterial isolation methods to detect Streptococcus agalactiae (GBS) carriage in women at 35-37 weeks’ gestation. Patients and Method: Use of SYBR Green real-time PCR and bacterial isolation methods to detect GBS in 116 women at 35 - 37 weeks’ gestation. Results: The rate of carrier of GBS in women at 35 - 37 weeks gestation was 9.5% (11 pregnant women), in which real-time PCR method was positive in all positive GBS women, while bacterial culture method was positive at 6% (7 pregnant women). These methods (culture and real-time PCR) had substantial agreement with the value of Kappa is 0,77. Checking for the targeted sequence amplification of real-time PCR by the curve of melting temperature and agarose electrophoresis of amplified product, the real-time PCR product was correctly targeted at the expected genetic sequence. Conclusion: SYBR Green real-time PCR method for detecting GBS in pregnant women is useful, low-cost and easy for performing. Therefore, it is suitable for detecting GBS in diagnostic laboratories where real-time PCRs are available. Key words: Streptococcus agalactiae (GBS), real-time PCR, pregnant woman

The investigation of antibiotic resistance and rapid detection of group B Streptococcus (Bca) from vaginal specimens of pregnant women by colony PCR method

Introduction: Group B Streptococcus (GBS) is one of the most causes of neonatal infections. The bacterium colonizes genitourinary tracts of pregnant women and transmits to infants. The aim of this study was investigating colony PCR and culture methods to detection of GBS in pregnant women. Materials and methods: Hundred pregnant women, at the 35th and 37th weeks of pregnancy, were selected from the Obstetrics and Gynecology Unit of the Moatazedi and Shahid Chamran Hospitals in Kermanshah province. Specimens were collected from vaginal introitus and investigated by selective culture and colony PCR methods. Then, antibiotic resistance tests were performed according to the latest guidelines of Clinical and Laboratory Standards Institute (CLSI). Results: Prevalence of GBS colonization was shown to be 5% and 6% by the culture and colony PCR methods, respectively. Also, resistance rate to erythromycin, penicillin, vancomycin, and the clindamycin were determined to be 50%, 16.66%, 16.66% and 33.33 %, respectively. Moreover, the highest resistance was for erythromycin and the appropriate antibiotics were penicillin and then vancomycin. Conclusion: A higher prevalence of GBS colonization in pregnant women in the Kermanshah city of Iran was detected using colony PCR method compared to culture method.

Prevalence of Maternal Genital Tract Colonization by Group B Streptococcus From Western Province, Taif, Saudi Arabia

Background: Group B streptococcus (GBS) or Streptococcus agalactiae are members of the normal flora of the female genital tract. Maternal colonization has been found to be a major risk factor for invasive GBS disease within 6 days of birth. GBS has become the major cause of bacterial infections in the perinatal period, including bacteremia, amnionitis, endometritis, and urinary tract infection in pregnant women as well as sepsis and meningitis in neonates and young infants. Infection of the new born may be acquired by the intra-amniotic route or directly during passage through the birth canal. This study was undertaken to determine the prevalence of GBS colonization in pregnant women attending the antenatal clinic of Al-Hada Armed Forces Hospital in Western province, Taif, Saudi Arabia. This paper was the first data on incidence of GBS in pregnant women at Western province, Taif, Saudi Arabia. Methods: A total of 2,632 pregnant women were screened for GBS colonization between January and December 2014. Standard microbiological methods were used to isolate and identify GBS from vaginal and anorectal swabs obtained from study subjects. An antimicrobial susceptibility test was performed for all GBS isolates according to the criteria of the Clinical and Laboratory Standards Institute (CLSI) by disk diffusion method. Results: A total of 632 out of 2,632 (24%) pregnant women were colonized by GBS. Statistically significant association was observed for GBS colonization with any of socio-demographic characteristics of the study subjects including age, occupation, number of antenatal clinic visits, and type of gravida. All GBS strains were susceptible to penicillin, ampicillin, vancomycin and gentamicin, erythromycin, tetracycline, ceftriaxone, chloramphenicol, ciprofloxacin, clindamycin, and norfloxacin. Resistance was observed in some strains against clindamycin (0.18%). The data from the present study showed that incidence of GBS in Saudi pregnant women increased rapidly. These results are the first record of the database in Saudi Arabia at western province with high prevalence of GBS in pregnant women. Conclusion: This study showed that prevalence of GBS colonization was 24% among the study subjects. The finding of this study was comparable with findings reported from developed and developing countries. However, further epidemiological investigations should be done in different parts of the country (all provinces) in order to know the actual GBS colonization rate in pregnant women and to consider the use of intrapartum antibiotics prophylaxis for prevention of early onset GBS-neonatal diseases, considering the accelerated demand for reducing neonatal morbidity and mortality due to GBS. J Clin Gynecol Obstet. 2015;4(3):258-264 doi: http://dx.doi.org/10.14740/jcgo341w

Risk Factors Associated with Group B Streptococcus Colonization and Their Effect on Pregnancy Outcome

Background: Group B Streptococcus (GBS) is an important cause of maternal and neonatal morbidity and mortality in many parts of the world. It has been implicated in adverse pregnancy outcomes. Maternal colonization has been found to be a major risk factor for invasive neonatal GBS disease. The main objective of this study was to identify the risk factors of Group B streptococcus colonization and its effect on pregnancy outcome. Methods: This was a prospective study in which pregnant women attending antenatal clinic (ANC) at Dr George Mukhari Hospital (DGMH) were recruited. These were at least18 years old and were at 16 weeks gestation. Vaginal and rectal swabs were taken at recruitment. Follow up of mothers until six weeks post-delivery and babies until three months of age was done. Results: A total of 340 pregnant women were then investigated for GBS colonization. Out of this number, 164 (48.2%) were GBS positive. The majority of the women (62.1%) were parity 1 and 2. Group B Streptococcus colonization was significant in women who had no matric education and who were unemployed. There was a significantly higher GBS colonization in women with previous history of miscarriages and stillbirths. The proportion of HIV positive, GBS colonized women was significant at 41.5% as compared to HIV negative GBS colonized (34.7%). Eight women (4.9%) presented with premature rupture of membranes (PROM) and the duration ranged from 0.5 to 72 hours. Ten (6.1%) women had preterm deliveries. Three (1.8%) women had wound sepsis post caesarean section and one (0.6%) had endometritis post vaginal delivery. A total of 7 (24.1%) babies were GBS positive. The number of live babies delivered was 167, with 1 case of miscarriage due to severe preeclampsia. There were 2 cases of early neonatal deaths which included 1 case of sepsis whereas the other one had multiple congenital abnormalities. Conclusion: Colonization by GBS in pregnant women at DGMH was high. Maternal risk factors identified were previous history of stillbirths/miscarriages, lack of education and being HIV positive. Overall pregnancy outcome both maternal and foetal was good.

Direct Identification of Streptococcus agalactiae in Vaginal Colonization in Pregnant Women Using Polymerase Chain Reaction

Background: Streptococcus agalactiae is a commensal organism, but it may cause infection in susceptible hosts including newborns as well as in pregnant or postpartum women. Applying rapid, accurate and sensitive methods for detecting group B Streptococcus (GBS) and receiving intrapartum antibiotic prophylaxis (IAP) at delivery have been demonstrated to increase the treatment possibility of carrier pregnant women and decrease the rates of GBS vertical transmission to infants. Objectives: The aim of this study was to compare the PCR assay results targeting 16S rRNA primers with the conventional culture method for direct detection of GBS in vaginal specimens of pregnant women at 35-37 weeks of gestation in Hamadan, Iran. Patients and Methods: A total of 203 vaginal specimens of pregnant women at 35-37 weeks of pregnancy from June 2013 through February 2014 were evaluated for detection of GBS, using culture method and polymerase chain reaction (PCR). Results: The prevalence of GBS in the 203 collected samples was 7.39% using culture method and 19.70% using PCR. Twenty-five specimens had positive PCR results and negative cultures; two specimens were positive in culture and negative by PCR.A total of 42 specimens (20.69%) were considered as true positive. The PCR results in comparison with culture (as the gold standard) revealed sensitivity of 88.24%, specificity of 87.44%, positive and negative predictive value of 35.71% and 98.95% respectively, and accuracy of 87.50%. Conclusions: Performing only culture method led to missed false negative carriers. Therefore, it is recommended that both the PCR assay and conventional culture method be routinely performed to detect GBS in pregnant women accurately. PCR diagnosis demonstrated a shorter turnaround time when compared with the time consuming culture method.

Epidemiology of Group B streptococcus isolated from pregnant women in Beijing, China

Group B Streptococcus (GBS) was the main causative organism of invasive infections in newborns due to vertical transmission from the colonized mothers. The study was undertaken to determine colonization rate, serotype distribution, genotypic characterization, antibiotic susceptibility profiles and molecular characteristics of erythromycin-resistant strains of GBS in pregnant women in Beijing, China. Vaginal–rectal swabs were collected from a total of 2850 pregnant women at 35–37 weeks of gestation, in which 7.1% were GBS positive. Serotypes III, Ia and V predominated. All isolates were penicillin susceptible, whereas the resistance rates for erythromycin and clindamycin were strikingly high.

Evaluation of Culture, Antigen Detection and Polymerase Chain Reaction for Detection of Vaginal Colonization of Group B Streptococcus (GBS) in Pregnant Women.

Group B Streptococcal infection is an important cause of neonatal morbidity and mortality. Early detection of perinatal vagino-rectal (VR) carriage of Group B Streptococcus (GBS) is important in the management of newborn infections. The objective of the study was to evaluate Culture, antigen detection and Polymerase chain reaction for detection of GBS in Pregnant women. Observational descriptive study was done in a tertiary care hospital in Southern India. VR swabs were collected from 50 women at 35 to 37 weeks of gestation. Culture in a selective Lim enrichment broth with subsequent culture on 5% sheep blood agar, Conventional PCR assay and antigen detection method were performed. The performance of antigen detection and PCR methods were compared with culture. STATISTICAL ANALYSIS was performed by Chi-Square test. GBS cultures were positive for 16% of the specimen (8 out of 50). Considering culture as a gold standard, Sensitivity, Specificity, Positive predictive value and Negative predictive value of antigen detection was 100%, 92.86%, 72.73%, 100% and similarly for that of PCR was 100%, 45.23%, 25.80%, 100%, respectively. Antigen detection method was the rapid, sensitive and specific test for the detection of GBS colonizers during pregnancy.

Comparison of various culture methods for isolation of group B streptococcus from intrapartum vaginal colonization.

Aims:Group B Streptococcus (GBS) is one of the most common causes of neonatal sepsis throughout the world. Reports of vaginal colonization of GBS in India are few and variable. A study was conducted on pregnant women in a tertiary care hospital to compare various methods for isolation of GBS, to study the prevalence of GBS in pregnant women in third trimester, and to determine risk factors for GBS colonization.Settings and Design:Observational descriptive study.Materials and Methods:High vaginal swabs from 150 pregnant women in their third trimester were used to compare three methods for isolation of GBS viz. direct culture on 5% Sheep Blood agar, direct culture on selective Columbia Blood Agar and culture in LIM enrichment broth with subsequent culture on 5% Sheep Blood agar. A history of associated risk factors was also taken.Statistical Analysis Used:Statistical analysis was performed by Chi–square test.Results:Isolation was best from LIM enrichment broth with subsequent culture on 5% Sheep Blood Agar. Prevalence of GBS colonization by using culture method was 12.67%. Most frequently associated risk factor was intrapartum fever (42.11%).Conclusions:Standard Culture Method using LIM enrichment should be adopted as standard practice for isolation of GBS from vaginal swabs.

Culture methods compared with the latex agglutination test for group B sterptococci detection during pregnancy

Background The administration of antibiotic prophylaxis to laboring women who harbor group B streptococci (GBS) depends on the identification of carriers. Objectives We sought to evaluate the diagnostic accuracy of the culture methods and the antigen agglutination test for the detection of GBS in pregnant women using a PCR assay. Patients and methods A prospective cross-sectional study of women at 35–37 weeks of gestation and fulfilling the selection criteria. Two vaginal swabs were collected from each woman: one for microbiological examination and the other for direct blood agar culture and broth inoculation. The inoculated broth was used for subculture, antigen detection by the latex agglutination test, and an scpB gene PCR assay. Isolated GBS were tested for their antimicrobial susceptibility test. Results A total of 30 out of 96 pregnant women were subjected to this study according to their inclusion criteria. The highest positive percent of GBS colonization was 36.6% detected by the scpB gene PCR assay, which was considered our standard, 33.3% by the antigen detection test, 26.7% by the culture method from the inoculated broth, and 23.3% from the direct culture method. The antigen detection from the inoculated broth by the latex agglutination test was the most accurate test compared with the other test methods, with a sensitivity of 90.9% (95% confidence interval 80.4–100) and 100% (95% confidence interval 96.4–100) for both the specificity and the positive predictive value, and a diagnostic accuracy of 96.7%. All detected GBS were 100% sensitive to penicillin and vancomycin, with 54.5% resistant to clindamycin and 45.5% resistant to erythromycin. However, there was no significant association between the clinical data and the GBS colonization. Conclusion Routine screening of pregnant women for vaginal GBS colonization by the antigen detection method from the inoculated broth, and treatment of positive cases with the proper antimicrobial drugs to prevent a possible neonatal infection, which may be acquired during delivery, should be carried out.

A combined enrichment/polymerase chain reaction based method for the routine screening of Streptococcus agalactiae in pregnant women.

Group B Streptococcus (GBS) is the most common cause of life-threatening infection in neonates. Guidelines from CDC recommend universal screening of pregnant women for rectovaginal GBS colonization. The objective of this study was to compare the performance of a combined enrichment/PCR based method targeting the atr gene in relation to culture using enrichment with selective broth medium (standard method) to identify the presence of GBS in pregnant women. Rectovaginal GBS samples from women at ≥36 weeks of pregnancy were obtained with a swab and analyzed by the two methods. A total of 89 samples were evaluated. The prevalence of positive results for GBS detection was considerable higher when assessed by the combined enrichment/PCR method than with the standard method (35.9% versus 22.5%, respectively). The results demonstrated that the use of selective enrichment broth followed by PCR targeting the atr gene is a highly sensitive, specific and accurate test for GBS screening in pregnant women, allowing the detection of the bacteria even in lightly colonized patients. This PCR methodology may provide a useful diagnostic tool for GBS detection and contributes for a more accurate and effective intrapartum antibiotic and lower newborn mortality and morbidity.