Phylogenetics of Mycoplasma hominis clinical strains associated with gynecological infections or infertility as disclosed by an expanded multilocus sequence typing scheme

Safa Boujemaa (1) , Amina Ben Allaya (1) , Béhija Mlik (1) , Helmi Mardassi (1) , Boutheina Ben Abdelmoumen Mardassi (1)

1 LR11IPT01 - Laboratoire de Microbiologie Moléculaire, Vaccinologie et Développement Biotechnologique

To our knowledge, the phylodistribution of M. hominis clinical strains associated with various pathological conditions of the urogenital tract has not been explored hitherto. Here we analyzed the genetic diversity and phylogenetic relationships among 59 M. hominis Tunisian clinical isolates, categorized as gynecological infections-or infertility-associated pathotypes. For this purpose, we developed an expanded multilocus sequence typing (eMLST) scheme, combining the previously reported multilocus sequence typing (MLST) loci (gyrB, tuf, ftsY, uvrA, gap) with a new selected set of putative virulence genes (p120', vaa, lmp1, lmp3, p60), referred herein to as multi-virulence-locus sequence typing (MVLST) loci. In doing so, M. hominis population was segregated into two distinct genetic lineages, which were differentially associated with each pathotype. Such a clear dichotomy was supported by several phylogenetic and population genetic analysis tools. Recombination was found to take place, but not sufficient enough to break down the overall clonal population structure of M. hominis, most likely as a result of purifying selection, which accommodated the most fit clones. In sum, and owing to the eMLST scheme described herein, we provide insightful data on the phylogenetics of M. hominis, arguing for the existence of genetically differentiable urogenital pathotypes. Mycoplasma hominis, which belongs to the Mycoplasmataceae family, in the Mollicutes class, was the first myco-plasma species isolated from humans in 1937 1. It resides, as a commensal, in the lower urogenital tract of healthy persons. Under certain circumstances, M. hominis can cause a variety of genital infections such as bacterial vag-inosis, pelvic inflammatory disease, and cervicitis 2. This microorganism seems to be associated with pregnancy complications and neonatal diseases 3. In addition, several studies reported the pathogenic role of M. hominis in infertility 4,5. More interestingly, this species has been linked to a wide range of extragenital infections (septic arthritis, endocarditis, brain abscess), especially in immunocompromised patients 6-8. To better understand the epidemiology and the mode of spread of M. hominis, several molecular typing systems have been developed. These include Pulse-Field Gel Electrophoresis (PFGE), Restriction Fragment Length Polymorphism (RFLP) analysis, Amplified Fragment Length Polymorphism (AFLP), and Random Amplified Polymorphic DNA (RADP). All these methods have revealed a high degree of both genetic and antigenic het-erogeneity among M. hominis strains 9-12. Although informative, these approaches proved to be quite difficult to

Domaines: Sciences du Vivant [q-bio]

Safa Boujemaa, Amina Ben Allaya, Béhija Mlik, Helmi Mardassi, Boutheina Ben Abdelmoumen Mardassi. Phylogenetics of Mycoplasma hominis clinical strains associated with gynecological infections or infertility as disclosed by an expanded multilocus sequence typing scheme. Scientific Reports, 2018, 8 (1), ⟨10.1038/s41598-018-33260-x⟩. ⟨pasteur-01990488⟩