Prevalence of Escherichia coli and analysis of virulence factors in endocervical cultures of pregnant women.

SCALISE MARÍA LUJÁN; LEONINO PATRICIA; PEREYRA ADRIANA; CASALE ROBERTO; FERREIROS JOSÉ A; SACERDOTI FLAVIA; IBARRA CRISTINA

Mar del Plata

Congreso; LXIV Reunión Anual de la Sociedad Argentina de Investigación Clínica.; 2019

Sociedad Argentina de Investigación Clínica

Presence of E.coli in the endocervicalmicrobiome has been associated to pregnancy complications. We have previouslyreported that Shiga toxin (Stx) producing E.coli (STEC) infections during pregnancy may cause maternal or fetal damagemediated by Stx2 in rats in early stage of gestation. In addition, Stx2inhibits migration, invasion and cell viability in extravillous trophoblast human cells of firsttrimester. Therefore, we propose to studythe presence of STEC in female genital tract in the pregnant women sincemightbe risk factor during gestation. Our objective was toidentify different virulence factors of STECcultures of endocervix of pregnant women. Endocervical swabs from 103 asymptomatic pregnant women with gestationalage of 14 to 30 weeks from the National Hospital Posadas were enrolled. Sampleswere enriched in Tryptic Soy Broth and sub-cultivated on sorbitol-MacConkey (SMAC) agarin order to detect no sorbitol fermenting colonies, characteristic of STEC.Genomic DNA was purified from colonies and the presence of the uidA gene, exclusivefor E. coli was analyzed by polymerase chain reaction (PCR). Positive colonies for uidA were checkedfor rfbO157, lpfAO113,hcp, eae, stx1, stx2a genes. STEC strainspositive for stx2 genes were also cultured in the presence of mitomycin C (2µg/ml) to evaluate maximum expression of Stx2 by viability assays on Vero cells. ThePCR results showed that 16/103 samples were positive for SMAC agar and 15/103were positive for the uidA gene. Furthermore, 6/15 E. coli expressed lpfAO113 and hcp, and 9/15E. coli expressed stx2 being only one sample positive for stx2a variant. All of them werenegative for rfbO157, eae. stx1 genes. One STEC strainpositive for stx2 gene showed cytotoxiceffects even in absence ofmitomycin C. Our study confirmed the prevalence of Ecoli in endocervical samples ofpregnant women froma public hospital in Buenos Aires.        <!-- /* Font Definitions */ @font-face{font-family:"Cambria Math";panose-1:2 4 5 3 5 4 6 3 2 4;mso-font-charset:0;mso-generic-font-family:roman;mso-font-pitch:variable;mso-font-signature:-536869121 1107305727 33554432 0 415 0;}@font-face{font-family:Calibri;panose-1:2 15 5 2 2 2 4 3 2 4;mso-font-charset:0;mso-generic-font-family:swiss;mso-font-pitch:variable;mso-font-signature:-469750017 -1073732485 9 0 511 0;} /* Style Definitions */ p.MsoNormal, li.MsoNormal, div.MsoNormal{mso-style-unhide:no;mso-style-qformat:yes;mso-style-parent:"";margin-top:0cm;margin-right:0cm;margin-bottom:10.0pt;margin-left:0cm;line-height:115%;mso-pagination:widow-orphan;font-size:11.0pt;font-family:"Calibri",sans-serif;mso-ascii-font-family:Calibri;mso-ascii-theme-font:minor-latin;mso-fareast-font-family:Calibri;mso-fareast-theme-font:minor-latin;mso-hansi-font-family:Calibri;mso-hansi-theme-font:minor-latin;mso-bidi-font-family:"Times New Roman";mso-bidi-theme-font:minor-bidi;mso-ansi-language:EN-US;mso-fareast-language:EN-US;}span.highlight{mso-style-name:highlight;mso-style-unhide:no;}.MsoChpDefault{mso-style-type:export-only;mso-default-props:yes;font-size:11.0pt;mso-ansi-font-size:11.0pt;mso-bidi-font-size:11.0pt;font-family:"Calibri",sans-serif;mso-ascii-font-family:Calibri;mso-ascii-theme-font:minor-latin;mso-fareast-font-family:Calibri;mso-fareast-theme-font:minor-latin;mso-hansi-font-family:Calibri;mso-hansi-theme-font:minor-latin;mso-bidi-font-family:"Times New Roman";mso-bidi-theme-font:minor-bidi;mso-fareast-language:EN-US;}.MsoPapDefault{mso-style-type:export-only;margin-bottom:10.0pt;line-height:115%;}size:612.0pt 792.0pt;margin:70.85pt 3.0cm 70.85pt 3.0cm;mso-header-margin:36.0pt;mso-footer-margin:36.0pt;mso-paper-source:0;}div.WordSection1{page:WordSection1;}