Identification of Shigatoxigenic and Enteropathogenic Escherichia coli Serotypes in Healthy Young Dairy Calves in Belgium by Recto-Anal Mucosal Swabbing

Abstract

Enterohemorrhagic Escherichia coli (EHEC), enteropathogenic E. coli (EPEC), and Shigatoxigenic E. coli (STEC) are carried by healthy adult cattle and even more frequently by young calves in their intestinal tract, especially at the height of the recto-anal junction. The purpose of the present study was to assess the presence of ten EHEC, EPEC, and/or STEC O serotypes (O5, O26, O80, O103, O111, O118, O121, O145, O157, and O165) in calves sampled via recto-anal mucosal swabs (RAMS) at three dairy farms in Belgium. A total of 233 RAMS were collected on three consecutive occasions from healthy <6-month-old Holstein-Friesian calves and submitted to a PCR targeting the eae, stx1, and stx2 genes after non-selective overnight enrichment growth. The 148 RAMS testing positive were streaked on four (semi-)selective agar media; of the 2146 colonies tested, 294 from 69 RAMS were PCR-confirmed as EHEC, EPEC, or STEC. The most frequent virulotype was eae+ EPEC and the second one was stx1+ stx2+ STEC, while the eae+ stx1+ and eae+ stx1+ stx2+ virulotypes were the most frequent among EHEC. The majority of EHEC (73%) tested positive for one of the five O serotypes detected (O26, O103, O111, O145, or O157) vs. 23% of EPEC and 45% of STEC. Similarly, more RAMS (73%) harbored EHEC isolates positive for those five serotypes compared to EPEC (53%) or STEC (52%). This survey confirms that (i) healthy young dairy calves are asymptomatic carriers of EHEC and EPEC in Belgium; (ii) the carrier state rates, the virulotypes, and the identified O serotypes differ between farms and in time; and (iii) a majority of EPEC belong to so far unidentified O serotypes.

Escherichia coli O80 in Healthy Cattle: Absence of Shigatoxigenic and Enteropathogenic E. coli O80:H2 and (Phylo) Genomics of Non-Clonal Complex 165 E. coli O80

“…In comparison with several other AE-STEC serotypes, cattle are highly suspected as the source of contamination, since they can be asymptomatic carriers in their intestines [ 1 ]. However, surveys to isolate AE-STEC or EPEC O80:H2 from healthy adult cattle or young calves have been so far unfruitful, with a very few sporadic exceptions [ 6 , 13 , 17 , 21 , 22 ].…”

“…Ruminants, especially cattle, are considered the most frequent source of human infection by the classical AE-STEC serotypes via foodstuffs contaminated by their faecal materials, since they can be asymptomatic carriers in their intestines [ 1 ]. However, the European Food Safety Agency reports no detection of AE-STEC O80:H2 in food in 2019 and 2020 [ 11 , 12 ], although they have been sporadically isolated from healthy cattle and dairy products in Spain and France, but not as yet in Belgium, in the past [ 6 , 13 , 17 , 21 , 22 ]. One possible reason is that AE-STEC O80:H2 were present under the detection limits of the different methodologies applied during those surveys.…”

Identification of Five Serotypes of Enteropathogenic Escherichia coli from Diarrheic Calves and Healthy Cattle in Belgium and Comparative Genomics with Shigatoxigenic E. coli

“…The EPEC, from healthy cattle and calves, but not all from diarrheic calves, had already been tested with all PCRs for the "gang of seven" and three other O serotypes (O5, O80, and O118) [4,6,7], the ten most frequent and pathogenic STEC serogroups in humans and animals [8,9]. Therefore, a new list of priority serotypes of human and calf AE-STEC is proposed in this paper: the "gang of ten" (O5:H-, O26:H11, O80:H2, O103:H2, O111:H-, O118:H16, O121:H19, O145:H-, O157:H7, and O165:H25).…”

Serotypes, Virulence Factors and Antibiograms of Escherichia coli Isolated from Diarrhetic Calves in Egypt: A review

“…Serotypes of E.coli commonly isolated from calves suffering from diarrhea in countries otherthan Egypt during 2010-2020. ( Vagh, et al, 2010;Vagh, et al, 2010;Nizza, et al, 2010, Nguyen, et al, 2011, Irshad et al, 2012, Wani et al, 2013, Shahrani, et al ., 2014, JAROS, et al ., 2016, Habets ,et al, 2020. Serotypes of E.coli commonly isolated from calves suffering from diarrhea in countries otherthan Egypt during 2010-2020 were O15 (23.5%), O111(19.03%), O145(19%), O157(16.18%), O56(14.28%), O82(11.9%), O91(11.9%), O8(10.52%), O103(10.49%), O26(10.16%), O164(9.52%), O128(9.35%), O119(8.6%), O20(6.38%),O45(5.5%), O169(4.76%), O3(4.76%), O4(4.76%), O16(4.76%), O66(4.76%), O131(4.76%), O132(4.76%), O100(4.76%), O171(4.76%), O97(4.76%), O48(4.76%), O17(4.76%), O89(4.76%), O5(4.60%), O76(4.53%), O25 (4.53%), O9(4.3%), O79(4.3%), O21 (4.3%), O53(4.3%), O101(4.3%), O117 (4.3%), O1(4.3%), O18(4.3%), O113(3.73%) and O121(3.2%).…”