Incidence of maternal GBS colonization and neonatal GBS disease among very low birth weight Polish neonates

Do NAAT-Based Methods Increase the Diagnostic Sensitivity of Streptococcus agalactiae Carriage Detection in Pregnant Women?

The aim of the study was to evaluate particular polymerase chain reaction primers targeting selected representative genes and the influence of a preincubation step in a selective broth on the sensitivity of group B Streptococcus (GBS) detection by nucleic acid amplification techniques (NAAT). Research samples were vaginal and rectal swabs collected in duplicate from 97 pregnant women. They were used for enrichment broth culture-based diagnostics, bacterial DNA isolation, and amplification, using primers based on species-specific 16S rRNA, atr and cfb genes. To assess the sensitivity of GBS detection, additional isolation of samples preincubated in Todd-Hewitt broth with colistin and nalidixic acid was performed and then subjected to amplification again. The introduction of the preincubation step increased the sensitivity of GBS detection by about 33-63%. Moreover, NAAT made it possible to identify GBS DNA in an additional six samples that were negative in culture. The highest number of true positive results compared to the culture was obtained with the atr gene primers, as compared to cfb and 16S rRNA primers. Isolation of bacterial DNA after preincubation in enrichment broth significantly increases the sensitivity of NAAT-based methods applied for the detection of GBS from vaginal and rectal swabs. In the case of the cfb gene, the use of an additional gene to ensure the appropriate results should be considered.

Maternal risk factors and pregnancy complications associated with low birth weight neonates in preterm birth

AIM

To explore the association between common pregnancy complications and low birth weight (LBW) neonates in preterm birth.

METHODS

The study included 1764 pregnant women who experienced a single birth prematurely at a city hospital in Guangzhou, China between January 1, 2017 and December 31, 2019. A total of 874 normal birth weight neonates and 890 LBW neonates were included. Multivariate logistic regression analysis was conducted to identify and measure risk factors; two-tailed test was applied, with a p ≤ 0.05 considered statistically significant.

RESULTS

Hypertension was the primary risk factor of LBW in preterm neonates, odds ratio (OR) = 2.912 (p < 0.001; 95% confidence interval [CI], 2.044-4.149), followed by hypothyroidism, OR = 1.807 (p = 0.046; 95% CI, 1.012-3.226), placental abruption, OR = 1.759 (p = 0.049; 95% CI, 1.002-3.087), reproductive tract infection, OR = 1.746 (p < 0.001; 95% CI, 1.325-2.301), abnormal amniotic fluid volume, OR = 1.737 (p = 0.003; 95% CI, 1.202-2.501), and fetal distress OR = 1.690 (p = 0.012; 95% CI, 1.120-2.551).

CONCLUSION

Preventing risk factors, such as hypertension, hypothyroidism, and reproductive tract infections, during pregnancy may reduce the incidence of LBW neonates.

Prevalence and Antimicrobial Susceptibility Profiles of Microorganisms Associated with Lower Reproductive Tract Infections in Women from Southern Poland-Retrospective Laboratory-Based Study

Objective: Female infections affecting the genital tract include sexually transmitted diseases, endogenous infections such as vulvovaginal candidiasis, bacterial vaginosis (BV) or aerobic vaginitis (AV) and healthcare-associated infections. The aim of the study was to analyze the etiological factors of the vaginal dysbacteriosis, and the antimicrobial susceptibility of the dominant bacterial and fungal infections in different age groups of outpatient women from the Silesian Region. Materials and methods: A retrospective laboratory-based multi-center study encompassed 4994 women of different ages in Silesian Voivodeship, in the south of Poland; patients who had vaginal swabs collected as per physicians’ orders during the period from 1 January 2017 until 30 June 2018 were included in the study. The inclusion criteria were: non-hospitalized female, aged ≤80, with suspected vulvovaginal candidiasis or bacterial vaginosis and clinical sings of infections. Results: Gram-positive cocci were the ones most often isolated: Enterococcus faecalis (29.2%) and Streptoccoccus agalactiae (13.1%), followed by bacilli from the Enterobacteriaceae group, including Escherichia coli (26.3%). The presence of Streptococcus agalactiae was confirmed in 13.1%, slightly more often in the 45–80 age group, and Gardnerella vaginalis in 6.4%, most often in women aged 15–24. The prevalence of yeast-like infections was 24.3%, Candida albicans accounted for 78.3%, whereas among C. non-albicans spp.—C. glabrata dominated (14.9%) followed by C. parapsilosis (3.8%). The highest resistance was observed only in Streptococcus agalactiae as the MLSB mechanism (Macrolide-lincosamide-streptogramin B) was identified in 38.6% of strains. The prevalence of vulvovaginal candidiasis was 24.3%, the highest in women aged 15–44. Conclusions: Drug resistance in studied vulvovaginitis was associated only with Streptococcus agalactiae. A high proportion of yeast-like aetiology was found, probably associated with recurrent infections. In the analyzed cases only the Amsel criteria and culture methods were used for diagnosis without preparations and microbiological Nugent criteria.

Maternal obesity and the risk of group B streptococcal colonisation in pregnant women

The aim of the study was to test if maternal obesity and being overweight are independent risk factors for rectovaginal Group B Streptococcus (GBS) colonisation in pregnancy and for early onset GBS disease in the neonate. A case-control study of 9877 deliveries was conducted. The obese gravidas were significantly more likely to be colonised by GBS when compared with non-obese gravidas (22.7% versus 17.5%, P < .001). Obese gravidas were still 33% more likely than non-obese women to test positive for GBS after adjusting for the perinatal factors (adjusted OR 1.33 [95% CI 1.12-1.56]). The risk of early onset GBS disease was not calculated due to its very low incidence. The conclusion is that maternal obesity is a significant risk factor for GBS colonisation at term. Impact statement What is already known on this subject? Group B Streptococcus (GBS) is as an important cause of perinatal mortality and morbidity if prophylaxis is not performed. Intrapartum antibiotics are given if the carrier status is positive or unknown, provided that the risk factors are present. What do the results of this study add? Maternal obesity is a significant and independent risk factor for GBS colonisation at term. What are the implications of these findings for clinical practice and/or further research? Maternal obesity may be considered as a risk factor that should be taken into account in strategies for reducing GBS disease in neonates.

Prevalence of colonisation by group B streptococcus in pregnant patients in Taguatinga, Federal District, Brazil: a cross-sectional study

PROPOSE

Group B streptococcus is responsible for severe infections in neonates resulting from vertical transmission from pregnant women colonized in the anal, perineal or vaginal regions. The identification of colonized patients and use of intrapartum prophylaxis may reduce the risk of neonatal infection.

METHODS

A cross-sectional study of pregnant women of gestational age between 35 and 37 weeks was conducted. Material was collected from patients for laboratory identification of group B streptococcus. Epidemiological data, including weight, height, body mass index, antibiotic use during pregnancy, pathologies during pregnancy (diabetes, hypertensive diseases, and hypothyroidism), twinning, and others, were also collected from patients.

RESULTS

The sample consisted of 501 pregnant women, and the prevalence of group B streptococcus was 14%. The mean age was 29 years, and the mean BMI was 30.7. During pregnancy, 204 patients had some type of infection, and 201 used antibiotics. Ninety-five patients were diagnosed with gestational diabetes mellitus and 74 with some type of hypertensive disease.

CONCLUSIONS

The prevalence of group B streptococcus observed did not differ from that observed in other studies. None of the factors studied can be considered as risk or protective factors for maternal colonization by group B streptococcus.

Epitope Mapping of Streptococcus agalactiae Elongation Factor Tu Protein Recognized by Human Sera

The elongation factor Tu has been identified as one of the most immunoreactive proteins that was recognized by human sera of GBS (group B streptococcus) positive patients. In this paper, we present the polypeptide-specific epitopes of the bacterial protein that are recognized by human antibodies: ²⁸LTAAITTVLARRLP⁴¹ (peptide no. 3) and ²⁹⁴GQVLAKPGSINPHTKF³⁰⁹ (peptide no. 21). To determine the shortest amino acid sequence recognized by antibodies, truncation peptide libraries were prepared using the PEPSCAN method. The analysis of immunoreactivity of peptides with sera of GBS positive and negative women revealed that the most immunoreactive sequence was ³⁰⁶HTKF³⁰⁹. Moreover, we observed that this sequence also showed the highest specificity which was based on ratio of reactivity with sera of GBS positive relative to sera of GBS negative patients. Epitope was synthetized on Wang resin with the Fmoc strategy. Our results open the possibility to use ³⁰⁶HTKF³⁰⁹ peptide in diagnostic assays to determine Streptococcus agalactiae infection in humans.

Isolation and anti-microbial susceptibility pattern of group B Streptococcus among pregnant women attending antenatal clinics in Ayder Referral Hospital and Mekelle Health Center, Mekelle, Northern Ethiopia

Background

Vaginal colonization with group B Streptococcus (GBS) is the predominant risk factor for the development of invasive neonatal GBS diseases and puts newborns at increased risk for morbidity and mortality. This study is aimed to determine the colonization rate and antimicrobial susceptibility pattern of group B Streptococcus among pregnant women.

Methods

Hospital based cross-sectional study was conducted from August to December 2014 at selected health facilities. A total of 139 antenatal clinics attendees, proportionally allocated, were recruited consecutively. Socio-demographic and clinical factors were collected using a structured questionnaire. Vaginal swabs were collected and cultured on Todd Hewitt broth and in 5 % sheep blood agar. Antimicrobial susceptibility test was done using Kirby-Bauer disk diffusion test. Statistical analysis was performed using Pearson’s Chi square test.

Results

Among the 139, 19 (13.7 %) were positive for GBS. All the GBS isolates were susceptible (100 %) to penicillin G, vancomycin, ampicillin, erythromycin and gentamicin. Two of the GBS isolates showed multidrug resistance against norfloxacin and ciprofloxacin. No statistically significant difference was observed for GBS colonization with any independent variables.

Conclusion

Vaginal colonization of GBS for the present study put emphasis on further investigation and accomplishment of routine GBS screening practices. The recovery of resistant strains to antimicrobial agents recommended in cases of penicillin allergic mothers indicates the importance of susceptibility test.

Direct identification of Streptococcus agalactiae and capsular type by real-time PCR in vaginal swabs from pregnant women

Most group B streptococcus (GBS) infections in newborns are with capsular type Ia, Ib, or III. To prevent these infections more effectively, we developed a real-time PCR method to simultaneously detect GBS species and identify these 3 capsular types in vaginal swab samples from women at 36-39 weeks of gestation. DNA to be detected included those of the dltS gene (encoding a histidine kinase specific to GBS) and cps genes encoding capsular types. PCR sensitivity was 10 CFU/well for a 33-35 threshold cycle. Results were obtained within 2 h. Direct PCR results were compared with results obtained from cultures. Samples numbering 1226 underwent PCR between September 2008 and August 2012. GBS positivity rates by direct PCR and after routine culture were 15.7% (n = 192) and 12.6% (n = 154), respectively. Sensitivity and specificity of direct PCR relative to culture were 96.1% and 95.9%. Of GBS positive samples identified by PCR, capsular types determined directly by real-time PCR were Ia (n = 24), Ib (n = 32), and III (n = 26). Real-time PCR using our designed cycling probe is a practical, highly sensitive method for identification of GBS in pregnant carriers, allowing use of prophylactic intrapartum antibiotics in time to cover the possibility of unexpected premature birth.