Maternal group B Streptococcus recto vaginal colonization increases the odds of stillbirth: evidence from Eastern Ethiopia

Yadeta, Tesfaye Assebe; Worku, Alemayehu; Egata, Gudina; Seyoum, Berhanu; Marami, Dadi; Berhane, Yemane

doi:10.1186/s12884-018-2044-2

Cited by 16 publications

(22 citation statements)

References 41 publications

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“…This result is found in the non-susceptibility ranges of 18.2–40.9% for clindamycin and 20.8–50% for erythromycin in other settings of Ethiopia. 38 , 47 , 52 , 54 However, 22.6% of non-susceptibility to erythromycin and 52.4% to clindamycin was reported in Egypt 55 and China, 58 respectively.…”

Section: Discussionmentioning

confidence: 99%

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Group B Streptococci Vaginal-Recto Colonization, Vertical Transmission to Newborns, Antimicrobial Susceptibility Profile and Associated Factors in Selected Health Facilities of Bahir Dar City: A Cross-Sectional Study

Leykun¹,

Genet²,

Mulu³

2021

IDR

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Background Group B streptococci (GBS) is an important pathogen involved in stillbirths, neonatal deaths and neurological defects, and the occurrence of multi-drug resistance (MDR) is an alarming issue. This study determined the prevalence of GBS colonization in pregnant women and newborns, the proportion of vertical transmission, antimicrobial susceptibility profiles of isolates, and the factors associated with colonization and vertical transmission. Methods A cross-sectional study was conducted from March 1, 2021 to June 30, 2021, at selected health facilities of Bahir Dar city. Vaginal-recto swabs from 292 pregnant women and pooled ear, nasal and umbilical swabs from 292 newborns were collected. GBS were identified following standard microbiological protocols. Antimicrobial susceptibility testing was performed using modified Kirby–Bauer disk diffusion method and interpreted by the accepted 2020 CLSI M100 guidelines. Logistic regression analysis was computed. Results Overall, 54 (18.5%) of pregnant women and 22 (7.5%) of newborns had GBS colonization. The proportion of GBS vertical transmission was 22 (40.7%). Group B Streptococcus isolates scored susceptibility to penicillin, ampicillin and vancomycin with 88.9%, 90.7%, and 96.3% for pregnant women and 86.4%, 90.9% and 95.9% for newborns, respectively. A high percentage of non-susceptibility was found for clindamycin and erythromycin with 33.3% and 25.9% for pregnant women and 31.8% and 22.7% from newborns, respectively. Besides, 19 (35.2%) GBS from pregnant women and 8 (36.4%) from newborns were MDR. Group B streptococci colonization was significantly associated with delivery before 37th week of gestation (AOR=2.77, 95% CI 1.14–6.68) and history of stillbirth (AOR=3.13, 95% CI 1.13–8.70). Conclusion Pregnant women vaginal-recto GBS colonization and transmission to newborns connected with MDR are a matter of concerns. Although non-susceptible GBS isolates are obtained, penicillin and vancomycin are relatively effective. The use of clindamycin, erythromycin and ceftriaxone should be guided by antimicrobial susceptibility testing. Genetic analysis is recommended to exactly identify the epidemiology of GBS strains, vertical transmission and antimicrobial resistance at the country level.

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Section: Discussionmentioning

confidence: 99%

“…23 , 24 , 50 , 51 However, the present result is lower compared to the 50–63.3% vertical transmission report from earlier studies in other parts of Ethiopia, 22 , 25 , 38 , 41 65% in India 21 and 54.2% in Turkey. 48 Conversely, a lower percentage of vertical transmission has been reported in Ethiopia 52 and China. 53 …”

Section: Discussionmentioning

confidence: 99%

Group B Streptococci Vaginal-Recto Colonization, Vertical Transmission to Newborns, Antimicrobial Susceptibility Profile and Associated Factors in Selected Health Facilities of Bahir Dar City: A Cross-Sectional Study

Leykun¹,

Genet²,

Mulu³

2021

IDR

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“…GBS can survive and grow in diverse environments within the human host. It can persist in the intestine, in the male and female reproductive tracts, within the placenta, the amniotic fluid, human blood, joint spaces, the neonatal lung, and the central nervous system [1,9,12,33,[95][96][97][98][99]. This environmental tolerance contributes to GBS virulence, allowing it to invade and grow within compartments that are prohibitive to other bacteria.…”

Section: Discussionmentioning

confidence: 99%

“…Streptococcus agalactiae (group B Streptococcus; GBS) is a cause of chorioamnionitis, stillbirth, and neonatal infections including bacteremia, pneumonia, and meningitis [1][2][3][4][5][6][7][8][9][10]. GBS is a common commensal of the intestinal and reproductive tracts in healthy adults, among whom invasive disease is rare [11,12].…”

Section: Introductionmentioning

confidence: 99%

Genome-Wide fitness analysis of group B Streptococcus in human amniotic fluid reveals a transcription factor that controls multiple virulence traits

et al. 2021

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Streptococcus agalactiae (group B Streptococcus; GBS) remains a dominant cause of serious neonatal infections. One aspect of GBS that renders it particularly virulent during the perinatal period is its ability to invade the chorioamniotic membranes and persist in amniotic fluid, which is nutritionally deplete and rich in fetal immunologic factors such as antimicrobial peptides. We used next-generation sequencing of transposon-genome junctions (Tn-seq) to identify five GBS genes that promote survival in the presence of human amniotic fluid. We confirmed our Tn-seq findings using a novel CRISPR inhibition (CRISPRi) gene expression knockdown system. This analysis showed that one gene, which encodes a GntR-class transcription factor that we named MrvR, conferred a significant fitness benefit to GBS in amniotic fluid. We generated an isogenic targeted deletion of the mrvR gene, which had a growth defect in amniotic fluid relative to the wild type parent strain. The mrvR deletion strain also showed a significant biofilm defect in vitro. Subsequent in vivo studies showed that while the mutant was able to cause persistent murine vaginal colonization, pregnant mice colonized with the mrvR deletion strain did not develop preterm labor despite consistent GBS invasion of the uterus and the fetoplacental units. In contrast, pregnant mice colonized with wild type GBS consistently deliver prematurely. In a sepsis model the mrvR deletion strain showed significantly decreased lethality. In order to better understand the mechanism by which this newly identified transcription factor controls GBS virulence, we performed RNA-seq on wild type and mrvR deletion GBS strains, which revealed that the transcription factor affects expression of a wide range of genes across the GBS chromosome. Nucleotide biosynthesis and salvage pathways were highly represented among the set of differentially expressed genes, suggesting that MrvR may be involved in regulating nucleotide availability.

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“…GBS can survive and grow in diverse environments within the human host. It can persist in the intestine, in the male and female reproductive tracts, within the placenta, the amniotic fluid, human blood, joint spaces, the neonatal lung, and the central nervous system (1, 9, 12, 33, 54–58). This environmental tolerance contributes to GBS virulence, allowing it to invade and grow within compartments that are prohibitive to other bacteria.…”

Section: Discussionmentioning

confidence: 99%

MrvR, a Group BStreptococcusTranscription Factor that Controls Multiple Virulence Traits

Dammann

et al. 2020

Preprint

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Streptococcus agalactiae (group B Streptococcus; GBS) remains a dominant cause of serious neonatal infections. One aspect of GBS that renders it particularly virulent during the perinatal period is its ability to invade the chorioamniotic membranes and persist in amniotic fluid, which is nutritionally deplete and rich in fetal immunologic factors such as antimicrobial peptides. We used next-generation sequencing of transposon-genome junctions (Tn-seq) to identify five GBS genes that promote survival in the presence of human amniotic fluid. We confirmed our Tn-seq findings using a novel CRISPR inhibition (CRISPRi) gene expression knockdown system. This analysis showed that one gene, which encodes a GntR-class transcription factor that we named MrvR, conferred a significant fitness benefit to GBS in amniotic fluid. We generated an isogenic targeted knockout of the mrvR gene, which we found to have a growth defect in amniotic fluid relative to the wild type parent strain. In addition to growing poorly in amniotic fluid, the knockout also showed a significant biofilm defect in vitro. Subsequent in vivo studies showed that, while the knockout was able to cause persistent murine vaginal colonization, pregnant mice colonized with the knockout strain did not develop preterm labor despite consistent GBS invasion of the uterus and the fetoplacental units. In contrast, pregnant mice colonized with wild type GBS consistently deliver prematurely. Similarly, in a sepsis model in which 87% of mice infected with wild type GBS died within three days, none of the mice infected with the knockout strain died. In order to better understand the mechanism by which this newly identified transcription factor controls GBS virulence, we performed electrophoresis mobility shift assays with recombinant MrvR and whole-genome transcriptomic analysis on the knockout and wild type strains. We show that MrvR binds to its own promoter region, suggesting likely self-regulation. RNA-seq revealed that the transcription factor affects expression of a wide range of genes across the GBS chromosome. Nucleotide biosynthesis and salvage pathways were highly represented among the set of differentially expressed genes, suggesting a linkage between purine or pyrimidine availability and activity of MrvR in multiple GBS virulence traits.

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Maternal group B Streptococcus recto vaginal colonization increases the odds of stillbirth: evidence from Eastern Ethiopia

Cited by 16 publications

References 41 publications

Group B Streptococci Vaginal-Recto Colonization, Vertical Transmission to Newborns, Antimicrobial Susceptibility Profile and Associated Factors in Selected Health Facilities of Bahir Dar City: A Cross-Sectional Study

Group B Streptococci Vaginal-Recto Colonization, Vertical Transmission to Newborns, Antimicrobial Susceptibility Profile and Associated Factors in Selected Health Facilities of Bahir Dar City: A Cross-Sectional Study

Genome-Wide fitness analysis of group B Streptococcus in human amniotic fluid reveals a transcription factor that controls multiple virulence traits

MrvR, a Group BStreptococcusTranscription Factor that Controls Multiple Virulence Traits

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