Lactobacillus Vaginal Microbiota of Women Attending a Reproductive Health Care Service in Benin City, Nigeria

Canadian Research & Development Centre for Probiotic, Lawson Health Research Institute, London, Ontario, Canada.
Sex Transm Dis (Impact Factor: 2.84). 02/2006; 33(1):59-62. DOI: 10.1097/01.olq.0000175367.15559.c4
Source: PubMed


The objective of this study was to determine whether Lactobacillus species found in African women differ substantially to those of white decent, described in previous studies. The vaginal microbiota play an important role in female health, and when the naturally dominant lactobacilli are displaced resulting in bacterial vaginosis (BV), the host is more at risk of acquiring sexually transmitted diseases, including HIV.
Vaginal samples were collected from 241 healthy, premenopausal Nigerian women, which were then Gram-stained for Nugent scoring. Microbial DNA was extracted, amplified using polymerase chain reaction (PCR) and Lactobacillus primers, and processed by denaturing gradient gel electrophoresis (DGGE). Lactobacillus species were identified by DNA sequencing and BLAST algorithm.
Of the samples, 207 (85.8%) had PCR products for lactobacilli, whereas 34 (14.2%) showed absence of lactobacilli, which correlated to the BV Nugent scores. On sequencing of amplicons, 149 subjects (72%) had sequence homologies to lactobacilli. Most women (64%) were colonized by L. iners as the predominant strain, similar to previous findings in Canadian and Swedish women. L. gasseri was found in 7.3% samples, followed by L. plantarum, L. suntoryeus, L. crispatus, L. rhamnosus, and other species.
The findings indicate that even with geographic, racial, and other differences, the predominant vaginal Lactobacillus species is similar to species in women from Northern countries.

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Available from: Kingsley C Anukam, Feb 20, 2014
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    • "For example, it has been shown that L. iners is often dominant in Caucasian and black African women [3]. Aberrations in the vaginal microbiota can result in bacterial vaginosis (BV), and higher rates of BV have been found in black women [4], [5], likely due to social and hygiene practices [6]–[8]. We isolated a strain of Lactobacillus pentosus and designated it KCA1. "
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    ABSTRACT: The vaginal microbiota, in particular Lactobacillus species, play an important role in female health through modulation of immunity, countering pathogens and maintaining a pH below 4.7. We report the isolation and genome sequence of Lactobacillus pentosus strain KCA1 (formally known as L. plantarum) from the vagina of a healthy Nigerian woman. The genome was sequenced using Illumina GA II technology. The resulting 16,920,226 paired-end reads were assembled with the Velvet tool. Contigs were annotated using the RAST server, and manually curated. A comparative analysis with the available genomes of L. pentosus IG1 and L. plantarum WCFS1 showed that over 15% of the predicted functional activities are found only in this strain. The strain has a chromosome sequence of 3,418,159 bp with a G+C content of 46.4%, and is devoid of plasmids. Novel gene clusters or variants of known genes relative to the reference genomes were found. In particular, the strain has loci encoding additional putative mannose phosphotransferase systems. Clusters of genes include those for utilization of hydantoin, isopropylmalate, malonate, rhamnosides, and genes for assimilation of polyglycans, suggesting the metabolic versatility of L. pentosus KCA1. Loci encoding putative phage defense systems were also found including clustered regularly interspaced short palindromic repeats (CRISPRs), abortive infection (Abi) systems and toxin-antitoxin systems (TA). A putative cluster of genes for biosynthesis of a cyclic bacteriocin precursor, here designated as pentocin KCA1 (penA) were identified. These findings add crucial information for understanding the genomic and geographic diversity of vaginal lactobacilli.
    Full-text · Article · Mar 2013 · PLoS ONE
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    • "crispatus, L. iners, L. gasseri, L. vaginalis and L. jensenii) that dominate the vaginal microbiota in our cohort are similar to those predominating in European and American women [1,2,24]. Our results are in accordance with studies conducted by Akunam et al. [19] in Nigeria and more recently, Damelin et al. in South Africa [18], where the same predominant vaginal Lactobacillus species were isolated. "
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    ABSTRACT: Background Bacterial vaginosis (BV), which is highly prevalent in the African population, is one of the most common vaginal syndromes affecting women in their reproductive age placing them at increased risk for sexually transmitted diseases including infection by human immunodeficiency virus-1. The vaginal microbiota of a healthy woman is often dominated by the species belonging to the genus Lactobacillus namely L. crispatus, L. gasseri, L. jensenii and L. iners, which have been extensively studied in European populations, albeit less so in South African women. In this study, we have therefore identified the vaginal Lactobacillus species in a group of 40 African women from Soweto, a township on the outskirts of Johannesburg, South Africa. Methods Identification was done by cultivating the lactobacilli on Rogosa agar, de Man-Rogosa-Sharpe (MRS) and Blood agar plates with 5% horse blood followed by sequencing of the 16S ribosomal DNA. BV was diagnosed on the basis of Nugent scores. Since some of the previous studies have shown that the lack of vaginal hydrogen peroxide (H2O2) producing lactobacilli is associated with bacterial vaginosis, the Lactobacillus isolates were also characterised for their production of H2O2. Results Cultivable Lactobacillus species were identified in 19 out of 21 women without BV, in three out of five women with intermediate microbiota and in eight out of 14 women with BV. We observed that L. crispatus, L. iners, L. jensenii, L. gasseri and L. vaginalis were the predominant species. The presence of L. crispatus was associated with normal vaginal microbiota (P = 0.024). High level of H2O2 producing lactobacilli were more often isolated from women with normal microbiota than from the women with BV, although not to a statistically significant degree (P = 0.064). Conclusion The vaginal Lactobacillus species isolated from the cohort of South African women are similar to those identified in European populations. In accordance with the other published studies, L. crispatus is related to a normal vaginal microbiota. Hydrogen peroxide production was not significantly associated to the BV status which could be attributed to the limited number of samples or to other antimicrobial factors that might be involved.
    Full-text · Article · Jan 2013 · BMC Infectious Diseases
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    • "Thinning of the vaginal mucus layer may also increase opportunities for HIV to access target cells in underlying mucosa. Given a preeminent ecological position in the vaginal environment [56], colonization of the female genital tract by Lactobacillus species is increasingly recognized as critical for overall vaginal health and resistance to infection by bacterial and viral pathogens, including HIV [57]. Under the influence of estrogen, vaginal epithelial cells store glycogen, which is hydrolysed to glucose and metabolized by vaginal bacteria [58]. "
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    ABSTRACT: Immune activation is increasingly recognized as a critical element of HIV infection and pathogenesis, causing expansion of virus founder populations at the mucosal port of entry and eventual exhaustion of cellular immune effectors. HIV susceptibility is well known to be influenced by concurrent sexually transmitted infections; however, the role of commensal vaginal microbiota is poorly characterized. Bacterial vaginosis (BV) is a risk factor for HIV acquisition in studies worldwide; however, the etiology of BV remains enigmatic, and the mechanisms by which BV increases HIV susceptibility are not fully defined. A model of how vaginal microbiota influences HIV transmission is considered in the context of a well-established cohort of HIV-exposed seronegative (HESN) commercial sex workers (CSW) in Nairobi, Kenya, many of whom have increased levels of anti-inflammatory factors in vaginal secretions and reduced peripheral immune activation (immune quiescence). Elucidation of the relationship between complex microbial communities and inflammatory mucosal responses underlying HIV infection should be a priority for future prevention-focussed research.
    Full-text · Article · Mar 2012
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