First molecular characterization of Streptococcus equi subsp zooepidemicus isolates from Argentinean mares through MLST tool

RETAMAR GABRIELA; SARCONE N; CASTILLO K; PEREZ AGUSTINA; BUSTOS CARLA; ETCHECOPAZ ALEJANDRO; GUILLEMI ELIANA; MUÑOZ ALEJANDRA

Buenos Aires

Congreso; 18TH INTERNATIONAL CONGRESS ON INFECTIOUS DISEASES; 2018

Streptococcus equi subsp zooepidemicus (S. zooepidemicus) is an opportunistic pathogen, considered part of the normal microbiota of the nasopharynx and vagina of horses. It is associated with diseases such as endometritis, abortions, pneumonias, abscesses, among others. This agent can cause severe disease in humans and other animals, such as dogs, monkeys, pigs, goats and several other mammalian species. Even, transmission from animals to humans has been demonstrated by close contact or by consuming unpasteurized dairy products. In humans, S. zooepidemicus can cause glomerulonephritis, rheumatic fever, meningitis and purulent arthritis and is currently considered an emerging pathogen. The ability to infect different host species implies a risk as a potential reservoir for human infections. S. zooepidemicus shows high genetic variability and for this reason, genotype characterization requires the study of genes not subjected to selective pressure. The aim of this study was to characterize S zooepidemicus genotypes from reproductive tract of mares through the MLST (Multilocus sequence typing) tool. Uterine, vagina and clitoral fossa samples were obtained from mares. After biochemical and molecular identification, fragments of seven housekeeping genes (carc, nrdE, nrdE, proS, spi, tdk, tpi and yqiL) were amplified and sequenced from 7 isolates by Sanger method. The sequences were compared with those available at the S. zooepidemicus database for Sequence Type (ST) assignment. A total of 4 different STs were identified for the 7 isolates. Two STs resulted new in the MLST database. Sequences not registered at the database were submitted for ST assignment. The ST 178 that has been previously isolated from 2 humans, a dog and an equine abortion, has been identified in three mares samples at the present study, highlighting that human and horses could carry closely related isolates that could be potentially pathogenic for humans, thus representing a risk to public health. We found identical genotypes at different anatomic sites from the same mare; this differs from previous publications that propose that strains isolated from the uterus have genetic differences from those normally isolated in vagina and clitoris fossa. This is the first genotype characterization of S. zooepidemicus isolates from Argentina.