Epidemiology of Shiga toxin-producingEscherichia coliO157 in very young calves in the North Island of New Zealand

Abstract

Healthy bobby calves are an asymptomatic reservoir of E. coli O157 in New Zealand and may represent an important source of infection for humans. Carriage was not associated with concentration of IgG in serum, carcass weight or gender.

Geographic Divergence of Bovine and Human Shiga Toxin–ProducingEscherichia coliO157:H7 Genotypes, New Zealand1

“…Fecal STEC O157:H7 isolates (n = 40) used in the study had been collected from cattle in previous studies conducted at beef slaughter plants in New Zealand during 2008 ( 8 ) and 2009–2011 ( 9 ). Data regarding the origin (North or South Island, region, farm location) of the cattle and the virulence profiles of the isolates (virulence genes ehx A, eae , stx 1, stx 2, and subtype stx 2c) were available.…”

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“…The overall prevalence of STEC in all samples and farms was 53%. Different prevalence of STEC among calves was studied and was 20% by Shaw et al, [23] 37.5% by Fukushima and Seki [24] 12.14% by Tahamtan et al, [25] 17.7% by Irshad et al, [26] and 22.7% by Kohansal and Asad [27].…”

Preweaned heifer management on US dairy operations: Part IV. Factors associated with the presence of Escherichia coli O157 in preweaned dairy heifers

“…Previous studies have shown a low prevalence of shedding in calves (Garber et al, 1995;Rugbjerg et al, 2003;Stenkamp-Strahm et al, 2017b), but this finding is not consistent across the literature (Mechie et al, 1997;Cobbold and Desmarchelier, 2000;Irshad et al, 2012;Jaros et al, 2016). When attempting to define factors that influence carriage of O157 by calves, studies have indicated that dietary shifts, the presence of multiple gastrointestinal (GI) pathogens, and administration of anticoccidial agents may play a role (Cray et al, 1998;Smith et al, 2004;Cho et al, 2013).…”

“…This is evidenced by previous studies. In one study that looked at 1-wk-old calves at slaughter, serum IgG values were not associated with O157 carriage (Irshad et al, 2012). Other results have shown that colostrum-fed experimentally infected calves did not have greatly different clinical outcomes than colostrumdeprived experimentally infected calves (Dean-Nystrom et al, 1997a).…”