Multiple-locus variable-nucleotide tandem repeat subtype analysis implicates European starlings as biological vectors for Escherichia coli O157:H7 in Ohio, USA

Abstract

Aims: To provide molecular epidemiological evidence of avian transmission of Escherichia coli O157:H7 between dairy farms in Ohio, this study was designed to identify genetic relatedness between isolates originating from bovine faecal samples and intestinal contents of European starlings captured on these farms. Methods and Results: During a three‐year period (2007–2009), cattle (n = 9000) and starlings (n = 430) on 150 different dairy farms in northern Ohio were sampled for the presence of E. coli O157:H7. Isolates were subjected to multiple‐locus variable‐nucleotide tandem repeat analysis (MLVA). Distinct allelic groups were identified on most farms; however, isolates clustering into three MLVA groups originated from both cattle and birds on different farms. Conclusions: Sharing of indistinguishable epidemiologically linked E. coli O157 MLVA subtypes between starlings and cattle on different farms supports the hypothesis that these birds contribute to the transmission of E. coli O157:H7 between dairy farms. Significance and Impact of Study: A continued need exists to identify and to improve preharvest measures for controlling E. coli O157:H7. Controlling wildlife intrusion, particularly European starlings, on livestock operations, may be an important strategy for reducing dissemination of E. coli O157:H7 between farms and thereby potentially decreasing the on‐farm prevalence of E. coli O157:H7 and enhancing the safety of the food supply.

European Starlings (Sturnus vulgaris) challenged with Escherichia coli O157 can carry and transmit the human pathogen to cattle

“…In conclusion, these data obtained from our laboratory‐based experiments are consistent with the epidemiological observations and ongoing research in our laboratory, supporting the role of European starlings in the epidemiology of E. coli O157 in livestock populations in the US (Wetzel and LeJeune 2006; Cerinicchiaro et al. 2011; Williams et al. 2011).…”

“…2006; Wetzel and LeJeune 2006). Our complementary studies have demonstrated an association between the number of starlings observed on dairy farms and the prevalence of E. coli O157 in milking cows (Cerinicchiaro et al 2011), and the isolation of indistinguishable molecular subtypes of E. coli O157 recovered from starlings and cattle (Williams et al. 2011).…”

Animal Reservoirs of Shiga Toxin-ProducingEscherichia coli

“…This was demonstrated by Williams et al (114), who reported that starlings and cattle on different farms had molecularly indistinguishable subtypes of STEC O157:H7, thus confirming that starlings were able to transmit STEC to different farms. Bolstering the role of starlings in STEC epidemiology is the fact that the number of starlings per milking dairy cow was also found to be significantly associated with the presence of STEC O157:H7 in bovine fecal pats (115).…”

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

“…For example, starlings have been implicated as biologic vectors in the dissemination of STEC among dairy farms in Ohio, United States ( 33 , 34 ), indicating that wildlife might play a key role in the epidemiology and ecology of STEC.…”