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

Objective  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.
Methods  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.
Results  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%).
Conclusion  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.     

Intrapartum Group B streptococcus detection by rapid polymerase chain reaction assay for the prevention of neonatal sepsis

Group B streptococcus (GBS) is a leading cause of infectious neonatal morbidity and mortality. Timely and accurate identification of colonized mothers is imperative so that antibioprophylaxis can be implemented during labour to reduce the risk of neonatal sepsis. We planned our study to analyse the diagnostic accuracy of an intrapartum PCR assay to identify GBS-colonized women and to allow the implementation of correct (i.e. at least 4 h) intrapartum antibiotic prophylaxis based on the PCR results. We included 695 women in labour who were tested for rectovaginal GBS carriage by culture and PCR. Women were also screened at 35–37 weeks of gestation. Intrapartum GBS colonization was 19.3%. Assay sensitivity was 81.0% for antenatal culture and 85.0% for intrapartum PCR; p 0.72. GBS colonization (n = 107) was known at least 4 h before delivery in 68 (64%) and 73 (68%) women based on antenatal culture and intrapartum PCR, respectively. Among 43 women delivering preterm, correct status was known at least 4 h before delivery in 10 (23%) and 32 (74%) women according to antenatal culture and intrapartum PCR, respectively. These results support the concept that GBS screening can be performed routinely during labour in a clinical setting. The intrapartum approach is at least as accurate as the antenatal screening, with the additional advantage of identifying women delivering preterm or not followed during pregnancy.     

A review of antibiotic resistance in Group B Streptococcus: the story so far

Abstract

Group B Streptococcus (GBS) is the leading cause of neonatal disease worldwide, and invasive disease in adults is becoming more prevalent. Currently, some countries adopt an intrapartum antibiotic prophylaxis regime to help prevent the transmission of GBS from mother to neonate during delivery. This precaution has reduced the incidence of GBS-associated early-onset disease; however, rates of late-onset disease and stillbirths associated with GBS infections remain unchanged. GBS is still recognized as being universally susceptible to beta-lactam antibiotics; however, there have been reports of reduced susceptibility to beta-lactams, including penicillin, in some countries. Resistance to second-line antibiotics, such as erythromycin and clindamycin, remains high amongst GBS, with several countries noting increased resistance rates in recent years. Moreover, resistance to other antibiotic classes, such as fluoroquinolones and aminoglycosides, also continues to rise. In instances where patients are allergic to penicillin and second-line antibiotics are ineffective, vancomycin is administered. While vancomycin, a last resort antibiotic, still remains largely effective, there have been two documented cases of vancomycin resistance in GBS. This review provides a comprehensive analysis of the prevalence of antibiotic resistance in GBS and outlines the specific resistance mechanisms identified in GBS isolates to date.     

Carriage of group B Streptococcus in pregnant women and newborns: a 2-year study at Perugia General Hospital

Objective: To study the prevalence of group B Streptococcus (GBS) colonization in pregnant women and their newborns at Perugia General Hospital.
Method: The number of mother-child pairs examined was 2300. Vaginal swabs were collected from the mothers at delivery, and auricular and pharyngeal swabs and gastric aspirate from the newborns at birth. Maternal risk factors for GBS disease, including premature delivery, intrapartum fever, prolonged rupture of membranes and multiple births, were evaluated.
Results: Maternal and neonatal colonization rates were 11.3% and 4.6%, respectively. GBS was isolated in 41.5% of the neonates born to colonized mothers and in 0.1% of those born to non-colonized mothers. No significant difference was observed in vertical transmission rates in the presence or absence of maternal risk factors. The external auditory canal was the most frequent (93.5%) and heavily colonized body site. Type Ib was the most common serotype among GBS isolates from mothers and babies. C surface protein was not detected in serotype V and VIII isolates, but was frequent in all other serotypes. Early-onset disease was observed in 0.4/1000 live births.
Conclusions: The prevalence of maternal and neonatal colonization at Perugia General Hospital was similar to that obtained in other studies performed in Italy. The external auditory canal was confirmed as the most reliable body site to be sampled for the detection of neonates exposed to maternal GBS colonization.     

Investigation of serotype distribution and resistance genes profile in group B Streptococcus isolated from pregnant women: a Chinese multicenter cohort study

We surveyed the group B Streptococcus (GBS) strains isolated from four teaching hospitals during 1‐year period to investigate the current serotypes and antimicrobial resistance status of these strains. A total of 231 non‐duplicate colonizing GBS isolates were collected from pregnant women. Antimicrobial susceptibility of these isolates was tested by the disk diffusion method. Serotype was performed by a multiplex polymerase chain reaction (PCR) method. Analysis of the resistance mechanisms was performed by PCR amplification and DNA sequencing. Seven serotypes (Ia, Ib, II, III, V, VI, and VIII) were identified, and the prevalence ranged from 0.9 to 35.9%. All isolates were susceptible to the penicillin, ceftriaxone, and vancomycin. The resistance of all the isolates to erythromycin, clindamycin, and levofloxacin was 61.5, 51.9, and 35.5%, respectively. The erythromycin resistance was mainly associated with the genes ermB and ermB‐mef(A/E) (69.8%). The most predominant phenotype was cMLSB (77.5%). Five gene panels, including gyrA, parC, parE, gyrA‐parC, and gyrA‐parC‐parE, were detected. The most predominant genotype was gyrA‐parC‐parE triple mutation (69.5%). The S81L in gyrA gene, S79Y mutation in parC gene, and H225Y mutation in parE gene were discovered. The isolates with serotype III, V, and Ia were the most important clone concerning the prevalence and resistance.     

Prevention of perinatal group B streptococcal infections: A review with an Indian perspective

Group B Streptococcus (GBS) is an important cause of maternal and neonatal morbidity and mortality in many parts of the world. Asymptomatic colonisation of the vagina and rectum with Group B streptococci is common in pregnancy. Maternal colonisation of GBS can vary depending on ethnicity and geographical distribution. Vertical transmission of this organism from mother to foetus may lead to neonatal GBS disease. Intra-partum use of antibiotics in these women has led to a decrease in the rate of early onset but not late onset GBS disease. Identification of women with GBS is the key factor in the prevention of perinatal GBS disease. There are different screening strategies available to identify women at risk of perinatal GBS disease. Clinicians continue to face the challenge of choosing between preventive strategies to reduce the impact of perinatal GBS disease. Controversy exists regarding the ideal preventive strategy. In India, the mortality and morbidity associated with the GBS disease remains largely a under-recognised problem. This comprehensive review summarises the salient features of GBS disease and discusses the epidemiology, risk factors, screening strategies, intra-partum antibiotic prophylaxis with an Indian perspective and how it compares with the Western nations.     

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.     

Hepatitis B virus infection among pregnant women in Haiti: A cross-sectional serosurvey

BackgroundHepatitis B vaccine administered shortly after birth is highly effective in preventing mother to child transmission (MTCT) of infection. While hepatitis B vaccine was introduced in Haiti as part of a combined pentavalent vaccine in 2012, a birth dose is not yet included in the immunization schedule.ObjectivesDetermine the seroprevalence of hepatitis B virus (HBV) infection among pregnant women to evaluate the risk of MTCT.Study designWe selected 1364 residual serum specimens collected during a 2012 human immunodeficiency virus (HIV) sentinel serosurvey among pregnant women attending antenatal care clinics. Haiti was stratified into two regions: West, which includes metropolitan Port-au-Prince, and non-West, which includes all other departments. We evaluated the association between demographic and socioeconomic characteristics and HIV infection with HBV infection.ResultsOf 1364 selected specimens, 1307 (96%) were available for testing. A total of 422 specimens (32.7%) tested positive for total anti-HBc (38.2% in West vs. 27% in non-West, p < 0.001), and 33 specimens (2.5%) were HBsAg positive (2.1% in West vs. 3% in non-West, p = 0.4). Of HBsAg positive specimens, 79% had detectable HBV DNA. Women aged 30 and older had more than double the odds of positive total anti-HBc than women aged 15–19 years (p < 0.001). Women with secondary (adjusted odds ratio (aOR) = 0.54; 95% CI: 0.36–0.81) and post-secondary education (aOR = 0.40, 95% CI: 0.19–0.79) had lower odds of total anti-HBc positivity compared with women with no education. HIV-status was not associated with HBV infection.ConclusionsHaiti has an intermediate endemicity of chronic HBV infection with high prevalence of positive HBV DNA among chronically infected women. Introduction of a universal birth dose of hepatitis B vaccine might help prevent perinatal HBV transmission.     

Prevalence, risk factors and virological profile of chronic hepatitis B virus infection in pregnant women in India

A large program was conducted by the Government of India to study the prevalence and profile of chronic hepatitis B virus (HBV) infection and its risk factors in pregnant women attending a tertiary care hospital in India. From September 2004 to December 2008 consecutive pregnant women attending the antenatal clinic were screened and those found positive for HBsAg were enrolled. Healthy non‐pregnant women of child‐bearing age, who presented for blood donation during the same period, served as controls. Women with symptoms of liver disease or those aware of their HBsAg status were excluded. Of the 20,104 pregnant women screened, 224 (1.1%) and of the 658 controls, 8 (1.2%) were HBsAg positive (P = ns). Previous blood transfusions and surgery were significant risk factors for infection with HBV. Of the women who were HBsAg positive, the ALT levels were normal in 54% of the women and HBV DNA levels were above 2,000 IU/ml in 71% of women. The median HBV DNA levels were higher in women who were HBeAg positive compared to the HBeAg negative group. The most common HBV genotype was D (84%) followed by A + D and A (8% each). In conclusion, the prevalence of HBsAg positivity among asymptomatic pregnant women in North India is 1.1% with 71% having high HBV DNA levels. These women may have a high risk of transmitting infection to their newborns. J. Med. Virol. 83:962–967, 2011. © 2011 Wiley‐Liss, Inc.     

荧光定量PCR在妊娠35～37周B族链球菌感染检测中的应用及妊娠结果分析

目的 运用荧光定量PCR法快速检测B族链球菌(GBS)感染并探讨其对妊娠结局及新生儿的影响.方法 收集1235例妊娠晚期孕妇阴道拭子,采用细菌培养法和荧光定量PCR法检测是否感染GBS,并比较GBS阳性和阴性两组患者的妊娠结局.结果 荧光定量PCR检测法阳性率显著高于细菌培养法(19.51％ vs.9.72％),且差异有统计学意义.两组孕妇妊娠结局和两组新生儿出生后健康状况如宫内感染、新生儿感染等发生率比较差异有统计学意义.结论 荧光定量PCR法检测GBS可早期预防治疗,有效改善孕妇妊娠结局和新生儿出生后健康状况,对孕晚期孕妇进行GBS感染的检测具有重要的临床意义.     

Comparison of scpB gene and cfb gene polymerase chain reaction assays with culture on Islam medium to detect Group B Streptococcus in pregnancy

Purpose: The purpose of the current study was to evaluate two low-costing PCR assays for rapid detection of Group B Streptococcus (GBS) in comparison to a pigment-based culture method. Materials and Methods: One-hundred and fifty vaginal swabs were collected from pregnant women at 35–40 weeks of gestation. Vaginal swabs were inoculated in selective enrichment broth medium, and examined using Islam medium, cfb PCR and scpB PCR assays. The demographic data were analysed to identify independent predictors of GBS colonization (age and gravidity), with GBS status as the dependent variable. Results: There was a significant association of age and gravidity with GBS colonization. GBS was detected in 25.3% of isolates by Islam medium, in 30.6% by using the cfb PCR assay and in 30% by using the scpB PCR assay. Conclusion: older pregnant women (≥30 years) and multigravida (>3 pregnancies) are at higher risk of GBS colonization. Both scpB-gene and cfb-gene-based PCR methods are highly sensitive techniques (100% sensitivity) compared to culture method. However, the specificities of the scpB and cfb PCR assays were 93.75 and 92.85%, respectively.     

Hepatitis B virus infection in Tunisian pregnant women: risk factors and viral DNA levels in HBe antigen negative women

Objective

To evaluate the seroprevalence and the risk factors of hepatitis B virus (HBV) infection in 2303 Tunisian pregnant women and to estimate the risk of perinatal transmission in women positive for hepatitis B surface antigen (HBsAg) but negative for hepatitis B e-antigen (HBeAg).

Material and methods

Positive samples were tested for HBeAg and anti-HBe antibody using enzyme immunoassays. Serum HBV-DNA was determined by real time PCR assay.

Results

Overall, 4% of women were HBsAg positive and for the majority of them (96.8%) this status was unknown. Only 1.4% of studied population were vaccinated previously against hepatitis B. Study of risk factors revealed association between the HBsAg status and presence of intrafamilial hepatitis cases (p < 0.05). Only four women were positive for HBeAg. Among patients with HBeAg negative status, only 11% were negative for HBV DNA. For the others, DNA level ranged from 34 to 10⁸ copies/ml; it was greater than 10⁴ copies/ml in 26.5% of them.

Conclusion

Hepatitis B virus (HBV) prevalence in pregnant women is of intermediate endemicity in Tunisia. Universal vaccination before pregnancy and antenatal screening is recommended. Pregnant women who are found to be HBsAg positive and HBeAg negative should be tested systematically for DNA level to evaluate the risk of perinatal infection and to prevent it by seroprophylaxy for babies or by treatment during the third trimester of pregnancy.     

723例O型血孕妇产前IgG抗-A（B）效价对新生儿红细胞致敏的研究

目的研究O型血孕妇产前IgG抗-A（B）血型抗体的效价对新生儿红细胞致敏情况,以预防新生儿溶血病的发生。方法采用抗人球蛋白法检测723例丈夫为非O型的O型血孕妇IgG抗-A或抗-B的ABO血型抗体效价,分娩时取脐静脉血做红细胞四项试验：血型、直接抗人球蛋白试验、游离抗体检测、释放试验。结果 723份血清中IgG抗-A（B）效价≥1∶64者有168例,异常检出率为23.24%;丈夫为A型、B型、AB型者,IgG抗-A（B）异常检出率分别为26.01%、20.13%、23.53%。当孕妇IgG抗-A（B）效价≤32时,新生儿血清学检验结果均为阴性,而效价为64、128、256、≥512新生儿脐血血清学检验结果阳性率分别为7.69%、64.29%、94.12%、100.00%。结论孕妇IgG抗-A（B）效价与新生儿红细胞致敏呈正相关,是产前预报母子血型不合而引起HDN的有效方法。可及早发现,及时治疗,减少由于母婴血型不合引起的溶血病发生。     

不良妊娠结局孕妇人微小病毒B19感染与垂直传播的研究

目的 探讨武汉地区妊娠妇女人微小病毒B19的感染状况、临床表现及母婴垂直传播途径。方法 以不良妊娠结局孕妇作为病例组,以同期妊娠顺利孕妇作为对照。采用非结构蛋白DNA巢式PCR检测方法及传统的结构蛋白巢式PCR方法作为并联实验,检测孕妇血清及部分妊娠产物中的人微小病毒B19DNA。结果 不良妊娠结局孕妇血清标本中B19病毒DNA检出率为26．32％(20／76),对照组血清标本检出率为6．98％(12／172例),二者差异具有显著性。B19病毒感染孕妇常见的临床表现有：孕期反复出现“流感样症状”、“咽喉炎、少数孕妇的面部及躯体出现丘疹样红斑、关节痛。平素健康状况较差及贫血者更易感染。在部分自然流产的绒毛组织、死胎及畸胎的胎盘组织、胎儿组织中检测到B19病毒DNA。结论 武汉地区妊娠妇女存在人微小病毒B19的感染,并可通过胎盘传播给胎儿,导致不良妊娠结局。     

Prevalence of group B streptococcal colonization in the healthy non-pregnant population: a systematic review and meta-analysis

BackgroundColonization and transmission precede invasive group B streptococcal (GBS) disease. Data on GBS colonization prevalence, detection methods and risk factors for carriage are relevant for vaccine development and to understand GBS pathogenesis.ObjectivesTo evaluate GBS colonization prevalence after the first week of life in the healthy non-pregnant population.Data sourcesPubmed/Medline, Embase, Latin American and Caribbean Health Sciences Literature, World Health Organization Library Information System, and Scopus. Search performed 12 January 2021 with search terms related to ‘GBS’ and ‘colonization, epidemiology, prevalence or screening’ without restrictions.Study eligibility criteriaAll studies that reported prevalence of GBS colonization (any site) in the healthy population.ParticipantsAll individuals (>6 days of age), with no indication of pregnancy, invasive disease or severe underlying immunological co-morbidities.MethodsLogit transformation and a random effects model (DerSimonian and Laird) were used to pool colonization estimates. Subgroup analysis and meta-regression on a priori determined subgroups were performed.ResultsWe included 98 studies with 43 112 participants. Our search identified 9309 studies of which 8831 were excluded based on title and abstract and 380 after reading the full text. Colonization rates varied considerably between studies (I² = 97%), which could be partly explained by differences in culture methods (R² = 27%), culture sites (R² = 24%), continent (R² = 10%) and participant's age (R² = 6%). Higher prevalence was found with selective culture methods (19%, 95% CI 16%–23% versus non-selective methods 8%, 95% CI 6%–9%; p < 0.0001). Colonization rates were highest in rectum (19%, 95% CI 15%–24%), vagina (14%, 95% CI 12%–17%) and urethra (9%, 95% CI 5%–18%). In participants with negative rectal cultures, 7% (95% CI 5%–9%) had GBS cultured from another niche. Colonization prevalence was lower in children (6 months to 16 years; 3%, 95% CI 2%–5%) compared with adults (16%, 95% CI 14%–20%; p < 0.0001). Using selective culture methods in adults resulted in a prevalence of 26% (95% CI 19%–33%) rectal, 21% (95% CI 17%–25%) vaginal and 9% (95% CI 6%–14%) urethral colonization.ConclusionThe rectum is the most common body site colonized by GBS. The best approach to screen for any GBS colonization is to screen multiple body sites using selective culture methods.     

Molecular characterization of pathogenic group B streptococcus from a tertiary hospital in Shanxi,China: High incidence of sequence type 10 strains in infants/pregnant women

BackgroundGroup B streptococcus (GBS) is a leading cause of serious infection in infants. Understanding its regional molecular epidemiology is helpful for regulating efficient prevention practice.MethodsA retrospective study was conducted to collected data from infants and pregnant women with culture-proven GBS disease in the largest women and children's medical center in Shanxi between January 2017 and September 2019. All GBS isolates were analyzed by multi-locus sequence typing (MLST) as well as distribution of pilus island (PI) genes.ResultsA total of 54 GBS isolates were obtained from 36 (66.7%) pregnant women and 18 (33.3%) infants with invasive disease. Among invasive GBS strains, the most common sequence type was ST10 (72.2%, P < 0.05), followed by ST23 and ST19. The ST10 strain was also the leading sequence type in colonizing pregnant women (44.4%, P < 0.05). All of the isolates carried at least one pilus island. The most frequently detected pilus island was PI-1+PI-2a (85.2%, P < 0.05), followed in turn by PI-2a and PI-2b.ConclusionsOur study demonstrates that one hypervirulent clone, sequence type 10, accounts for a large proportion of invasive GBS disease in infants and colonizing pregnant women, and the PI-1+PI-2a sub-lineages should be noted in infant infections.