The Occurrence of Resistomes, Virulence Factors and Clonal Diversity of Escherichia coli and Staphylococci Isolated from the Semen of Men Attending Infertility Clinic in Lagos, Nigeria.

Background: Male factor infertility accounts for 40 - 60% of global couples suffering from infertility. Multiple antibacterial resistances have constituted a serious impediment against the effective eradication of non-specific bacteria etiology of male infertility; resistant genes are spread within and across bacterial species; producing progeny that are difficult to treat. Aim: We studied the resistance genes, as well as the virulence factors and clonal characteristics of E. coli and Staphylococci found in the semen of infertile men in Lagos. Methods: This was a cross-sectional study between October 2009 and December 2014. Results: Sixteen E. coli and 48 Staphylococci strains out of all isolates from the 226 infertile men were identified as multi-drug resistant (MDR) strains phenotypically, and were identified with PCR specific primers for E. coli and Staphylococci genes. The clonal characteristics of the strains were conducted using RAPD method. The study revealed that E. coli had the blaCTx-M gene in 25% of the strains, while Staphylococci had the MecA gene in 22.6% of the strains and the FemA gene in 12.9%. The genetic diversity of the strains found that E. coli had limited diversity with just 2 main groups and 3 clusters, all from the same genetic origin. On the other hand, Staphylococci had much more diversity with 6 main groups and 11 clusters. One group in particular was different from the rest. Conclusion: The blaCTx-M gene prevalence was high in E. coli, while the MecA gene was high among the Staphylococci. The presence of non-typeable genotypes is novel.