Characterization of mammary pathogenic Escherichia coli reveals the diversity of Escherichia coli isolates associated with bovine clinical mastitis in Brazil

• DOI: 10.3168/jds.2022-22126
• Publication Date: 2022-12-23T20:20:20Z
• Authors: Henrique Orsi; Felipe F. Guimarães; Domingos S. Leite; Simony T. Guerra; Sâmea F. Joaquim; Jose C.F. Pantoja; Rodrigo T. Hernandes; Simone B. Lucheis; Márcio G. Ribeiro; Helio Langoni; Vera L.M. Rall
• Keywords: Pathogenic Escherichia coli

Mammary pathogenic Escherichia coli (MPEC) is one of the most common pathogens associated with clinical mastitis. We analyzed isolates obtained from milk samples cows mastitis, collected 10 farms in Brazil, to verify molecular and phenotypic characteristics. A total 192 (4.5%) mammary E. were 4,275 analyzed, but we tested 161. assigned these phylogroups B1 (52.8%) (36.6%), although B2, C, D, E, unknown also occurred. All assessed for presence several genes encoding virulence factors, such as adhesins (sfaDE, papC, afaBC III, ecpA, fimH, papA, iha), toxins (hlyA, cnf1, sat, vat, cdt), siderophores (iroN, irp2, iucD, ireA, sitA), an invasion protein (ibeA), serum resistance proteins (traT, KpsMTII, ompT), B1, E showed up 8 genes. Two harbored locus enterocyte effacement (escN+) lack bundle-forming pilus (bfpB-) operon, which corresponds a profile subgroup diarrheagenic (aEPEC), thus being classified hybrid MPEC/aEPEC isolates. These displayed localized adherence-like pattern adherence HeLa cells able promote F-actin polymerization underneath adherent bacteria. Based on pulsed-field gel electrophoresis analyses, considerable genetic variability was observed. low index antimicrobial observed 2 extended-spectrum β-lactamase-producing identified, both harboring blaCTX-M15 gene, ST10 ST993 using multilocus sequence typing. 148 (91.2%) weak biofilm producers or formed no biofilm. Because raw still frequently consumed occurrence factor-encoding extraintestinal added can turn this veterinary medicine problem into public health concern.