Lactobacillus crispatus-dominated vaginal microbiome and Acinetobacter-dominated seminal microbiome support beneficial ART outcome.

INTRODUCTION: Despite the considerable progress made in assisted reproductive technologies (ART), the implantation rate of transferred embryos remains low and in many cases, the reasons for failure remain unclear. We aimed to determine the potential impact of female and male partners' reproductive tract microbiome composition on ART outcome. MATERIAL AND METHODS: The ART couples (n = 97) and healthy couples (n = 12) were recruited into the study. The smaller healthy group underwent a careful selection according to their reproductive and general health criteria. Both vaginal and semen samples were subjected to 16S rDNA sequencing to reveal the bacterial diversity and identify distinct microbial community types. Ethics statement The study was approved by the Ethics Review Committee on Human Research of Tartu University, Tartu, Estonia (protocol no. 193/T-16) on 31 May 2010. Participation in the research was voluntary. Written informed consent was obtained from all study participants. RESULTS: The men with Acinetobacter-associated community who had children in the past, had the highest ART success rate (P < 0.05). The women with bacterial vaginosis vaginal microbiome community and with L. iners-predominant and L. gasseri-predominant microbiome had a lower ART success rate than women with the L. crispatus-predominant or the mixed lactic-acid-bacteria-predominant type (P < 0.05). The 15 couples where both partners had beneficial microbiome types had a superior ART success rate of 53%, when compared with the rest of the couples (25%; P = 0.023). CONCLUSIONS: Microbiome disturbances in the genital tract of both partners tend to be associated with couple's infertility as well as lower ART success levels and may thus need attention before the ART procedure. The incorporation of genitourinary microbial screening as a part of the diagnostic evaluation process may become routine for ART patients if our results are confirmed by other studies.

Seminal microbiome in men with and without prostatitis.

OBJECTIVES: To profile the seminal microbiome applying next generation sequencing. METHODS: Semen samples of 67 men were involved in the study (21 men with and 46 men without prostatitis). Seminal microbiomes were profiled applying the method that uses combinatorial sequence tags attached to polymerase chain reaction primers that amplify the ribosomal ribonucleic acid V6 region. Amplified polymerase chain reaction products were sequenced using an Illumina paired-end protocol on HiSeq2000 platform. RESULTS: The most abundant phylum in semen was Firmicutes, comprising nearly half of the sequences found (median 41.7%, quartiles 28.5-47.2%) followed by Bacteroidetes, Proteobacteria and Actinobacteria. The counts of lactobacilli were higher in healthy men than prostatitis patients (27% [20.2-34.6%] vs 20.2% [4.9-25.0%]; P = 0.05), especially for Lactobacillus iners. Proteobacteria comprised higher proportions in prostatitis patients than healthy men. The species richness was higher in prostatitis patients than healthy men (inverted Simpson index 13.5 ± 5.8 vs 10.3 ± 4.0). CONCLUSIONS: The semen of chronic prostatitis patients contains fewer health-supporting lactobacilli, and has higher species diversity than that of healthy men. Firmicutes (especially lactobacilli), Bacteroidetes, Proteobacteria and Actinobacteria comprise the highest proportion of seminal microbiome.

Characterisation of probiotic properties in human vaginal lactobacilli strains.

BACKGROUND: Vaginal lactobacilli offer protection against recurrent urinary infections, bacterial vaginosis, and vaginal candidiasis. OBJECTIVE: To characterise the isolated vaginal lactobacilli strains for their probiotic properties and to compare their probiotic potential. METHODS: The Lactobacillus strains were isolated from vaginal samples by conventional culturing and identified by sequencing of the 16S rDNA fragment. Several functional properties were detected (production of hydrogen peroxide and lactic acid; antagonistic activity against Escherichia coli, Candida albicans, Candida glabrata, and Gardnerella vaginalis; auto-aggregation and adhesiveness) as well as safety (haemolytic activity, antibiotic susceptibility, presence of transferrable resistance genes). RESULTS: A total of 135 vaginal lactobacilli strains of three species, Lactobacillus crispatus (56%), Lactobacillus jensenii (26%), and Lactobacillus gasseri (18%) were characterised using several functional and safety tests. Most of L. crispatus (89%) and L. jensenii (86%) strains produced H2O2. The best lactic acid producers were L. gasseri (18.2±2.2 mg/ml) compared to L. crispatus (15.6±2.8 mg/ml) and L. jensenii (11.6±2.6 mg/ml) (p<0.0001; p<0.0001, respectively). L. crispatus strains showed significantly higher anti-E. coli activity compared to L. jensenii. L. gasseri strains expressed significantly lower anticandidal activity compared to L. crispatus and L. jensenii (p<0.0001). There was no significant difference between the species in antagonistic activity against G. vaginalis. Nearly a third of the strains were able to auto-aggregate while all the tested strains showed a good ability to adhere to HeLa cells. None of the tested lactobacilli caused haemolysis. Although phenotypical resistance was not found to ampicillin, chloramphenicol, erythromycin, gentamycin, tetracycline, and vancomycin, the erm(B), tet(M), and tet(K) were detected in some strains. All strains were resistant to metronidazole, trimethoprim/sulfamethoxazole, and kanamycin. CONCLUSIONS: Our study revealed that the production of different antimicrobial metabolites is highly strain-specific and that the metabolites are not correlated with each other. L. crispatus displays better antagonistic activity against E. coli and Candida spp. than L. gasseri and L. jensenii; therefore; a potential probiotic candidate could be found among L. crispatus strains.

Complementary seminovaginal microbiome in couples.

The genital tract microbiome is tightly associated with reproductive health. Although many research studies have been performed on the vaginal microbiome, current knowledge of the male microbiome is scarce, and parallel studies examining couples are extremely rare. In this work, we aimed to compare seminal and vaginal microbiomes in couples and to assess the influence of sexual intercourse on vaginal microbiome. The study included 23 couples. Microbiomes of semen and vaginal fluid (pre- and post-intercourse) were profiled using Illumina HiSeq2000 sequencing of the V6 region of 16S rRNA gene. Seminal communities were significantly more diverse, but with lower total bacterial concentrations than those of the vagina. Gardnerella vaginalis was predominant in half of the women whose partners had significant leukocytospermia, but only in one of 17 women who had a partner without leukocytospermia. There was significant decrease in the relative abundance of Lactobacillus crispatus after intercourse, and high concordance between semen and vaginal samples. Our data support the hypothesis that semen and vaginal microbiomes are in association, inasmuch as the predominance of G. vaginalis in female partners was significantly related to inflammation in male genital tracts.