Cervico-vaginal carriage rate of Escherichia coli in pregnant women receiving antinatal control in a public hospital of Buenos Aires

SCALISE M.LUJAN; LEONINO PATRICIA; PEREYRA ADRIANA; CASALE ROBERTO; FERREIROS JOSE, ; SACERDOTI FLAVIA; IBARRA CRISTINA

cuidad autonoma de Buenos Aires

Congreso; International Federation of Placenta Associations (IFPA2019); 2019

Objectives: Presence of Escherichia coli in the vaginal microbiome has beenassociated to pregnancy and neonatal complications. We have previouslyreported that Shiga toxin (Stx) producing E. coli (STEC) infections duringpregnancy may cause maternal or fetal damage mediated by Stx2 in rats.To our knowledge, it has not been reported the presence or colonization ofSTEC in vagina of pregnant women. We propose that the presence of STECin human vagina may be a risk factor for pregnancy and neonatal complications.Our objective was to investigate the presence of E. coli in cervico-vaginal cultures from pregnant women and to identify virulencefactors related to STEC infectionMethods: Cervico-vaginal swabs from 103 pregnant women with gestationalage of 14 to 30 weeks from the National Hospital A. Posadas wereenrolled. Samples were enriched in Tryptic Soy Broth and sub-cultivatedon sorbitol-MacConkey (SMAC) agar for 24 h in order to detect no sorbitolfermenting colonies, characteristic of STEC. Genomic DNA was purifiedfrom colonies and the presence of the uidA gene exclusive for E. coli wasanalyzed by PCR. Positive colonies for uidA were additionally checked forO157, eae and Stx2 genes currently associated with STEC virulence factorsResults: Of the 103 cervico-vaginal samples analyzed 16 showed coloniesin SMAC agar but none sample had sorbitol fermenting negative colonies.PCR studies showed that 15 samples carried out the uidA gene (14.5%, 15/103). In addition, 9 of them (60%, 9/15) expressed stx2 gene. All of themwere negative for O157 and eae genes.Conclusion: Our study confirmed the prevalence of E. coli in cervicovaginalfluid of pregnant women in Argentina. Furthermore, we detectedfor the first time the stx2 gene in several E. coli samples. These resultssuggest that STEC strains may colonize the vagina. Further studies areneeded in order to elucidate if the presence STEC in vagina may be a riskfor pregnancy complications.