04099naa a2200289 a 450000100080000000500110000800800410001902200280006002400400008810000190012824501160014726000090026350011310027252020580140365300150346165300130347665300140348965300560350365300340355970000170359370000140361070000160362470000130364070000150365370000190366877301220368710642892023-08-17       2023    bl uuuu     u00u1 u    #d  a2076-2607 (electronic).7 a10.3390/microorganisms110717042DOI1 aFERNÁNDEZ, M.  aShiga toxin-producing Escherichia coli (STEC) associated with calf mortality in Uruguay.h[electronic resource]  c2023  aArticle history: Received 17 May 2023; Revised 5 June 2023; Accepted 8 June 2023; Published 29 June 2023. -- Academic Editors: Kim Stanford, Flemming Scheutz, Chad R. Laing, Linda Chui, Nicole Van De Kar, Patricia Griffin, Tim A. McAllister and Gillian Tarr. -- This article belongs to the Special Issue The Science of Shiga Toxin-Producing (Verotoxin-Producing) Escherichia coli (STEC): An Ongoing One Health Journey toward Improved Health and Food Safety) (https://www.mdpi.com/journal/microorganisms/special_issues/STEC_VTEC ) -- LICENSE: Licensee MDPI, Basel, Switzerland. This article is an open access article distributed under the terms and conditions of the Creative Commons Attribution (CC BY) license (https://creativecommons.org/licenses/by/4.0/). -- FUNDING: This research was partially funded by the project PL-15 from "Instituto Nacional de Investigación Agropecuaria" (INIA).. -- Supplementary imaterials an be downloaded at: https://www.mdpi.com/article/10.3390/microorganisms11071704/s1. Table S1: Origin of the animals. Table S2: Virulence profiles in E. coli isolates recovered from dead animals (n = 221).  aABSTRACT.- In Uruguay, the mortality of dairy calves due to infectious diseases is high. Escherichia coli is a natural inhabitant of the intestinal microbiota, but can cause several infections. The aim of the work was to characterize E. coli isolates from intestinal and extraintestinal origin of dead newborn calves. Using PCR, virulence gene characteristics of pathogenic E. coli were searched. The pathogenic E. coli were molecularly characterized and the phylogroup, serogroup and the Stx subtype were determined. Antibiotic susceptibility was determined using the Kirby-Bauer disk diffusion method and plasmid-mediated quinolone resistance (PMQR) genes with PCR. Finally, clonal relationships were inferred using PFGE. Gene characteristics of the Shiga toxin-producing E. coli (STEC), Enteropathogenic E. coli (EPEC) and Necrotoxigenic E. coli (NTEC) were identified. The prevalence of the iucD, afa8E, f17, papC, stx1, eae and ehxA genes was high and no f5, f41, saa, sfaDE, cdtIV, lt, sta or stx2 were detected. The prevalence of STEC gene stx1 in the dead calves stood out and was higher compared with previous studies conducted in live calves, and STEC LEE+ (Enterohemorrhagic E. coli (EHEC)) isolates with stx1/eae/ehxA genotypes were more frequently identified in the intestinal than in the extraintestinal environment. E. coli isolates were assigned to phylogroups A, B1, D and E, and some belonged to the O111 serogroup. stx1a and stx1c subtypes were determined in STEC. A high prevalence of multi-resistance among STEC and qnrB genes was determined. The PFGE showed a high diversity of pathogenic strains with similar genetic profiles. It can be speculated that EHEC (stx1/eae/ehxA) could play an important role in mortality. The afa8E, f17G1 and papC genes could also have a role in calf mortality. Multidrug resistance defies disease treatment and increases the risk of death, while the potential transmissibility of genes to other species constitutes a threat to public health. © 2023 by the authors. Licensee MDPI, Basel, Switzerland.  aDairy calf  aMDR STEC  aMortality  aPLATAFORMA DE INVESTIGACIÓN EN SALUD ANIMAL - INIA  aShiga toxin-producing E. coli1 aCASAUX, M.L.1 aFRAGA, M.1 aVIGNOLI, R.1 aBADO, I.1 aZUNINO, P.1 aUMPIÉRREZ, A.  tMicroorganisms. 2023, Volume 11, Issue 7, p. 1704. https://doi.org/10.3390/microorganisms11071704   ---- OPEN ACCESS.