Prevalence and Characterization of Escherichia coli and Salmonella Strains Isolated from Stray Dog and Coyote Feces in a Major Leafy Greens Production Region at the United States-Mexico Border

Abstract

In 2010, Romaine lettuce grown in southern Arizona was implicated in a multi-state outbreak of Escherichia coli O145:H28 infections. This was the first known Shiga toxin-producing E. coli (STEC) outbreak traced to the southwest desert leafy green vegetable production region along the United States-Mexico border. Limited information exists on sources of STEC and other enteric zoonotic pathogens in domestic and wild animals in this region. According to local vegetable growers, unleashed or stray domestic dogs and free-roaming coyotes are a significant problem due to intrusions into their crop fields. During the 2010–2011 leafy greens growing season, we conducted a prevalence survey of STEC and Salmonella presence in stray dog and coyote feces. Fresh fecal samples from impounded dogs and coyotes from lands near produce fields were collected and cultured using extended enrichment and serogroup-specific immunomagnetic separation (IMS) followed by serotyping, pulsed-field gel electrophoresis (PFGE), and antimicrobial susceptibility testing. A total of 461 fecal samples were analyzed including 358 domestic dog and 103 coyote fecals. STEC was not detected, but atypical enteropathogenic E. coli (aEPEC) strains comprising 14 different serotypes were isolated from 13 (3.6%) dog and 5 (4.9%) coyote samples. Salmonella was cultured from 33 (9.2%) dog and 33 (32%) coyote samples comprising 29 serovars with 58% from dogs belonging to Senftenberg or Typhimurium. PFGE analysis revealed 17 aEPEC and 27 Salmonella distinct pulsotypes. Four (22.2%) of 18 aEPEC and 4 (6.1%) of 66 Salmonella isolates were resistant to two or more antibiotic classes. Our findings suggest that stray dogs and coyotes in the desert southwest may not be significant sources of STEC, but are potential reservoirs of other pathogenic E. coli and Salmonella. These results underscore the importance of good agriculture practices relating to mitigation of microbial risks from animal fecal deposits in the produce production area.

Multilaboratory Survey To Evaluate Salmonella Prevalence in Diarrheic and Nondiarrheic Dogs and Cats in the United States between 2012 and 2014

“…This is consistent with several surveys in dogs (32, 39, 45, 73). Other studies (42, 46, 58, 74–77) have reported younger and older animals as having a greater likelihood of serious infection.…”

“…This is similar to the findings of many other surveys (32, 44, 45, 84, 85, 89–91). Two of the isolates in the present study were resistant to three or more antibiotics.…”

Shiga-toxigenic Escherichia coli in ready-to-eat food staffs: Prevalence and distribution of putative virulence factors

“…They represented that 54.54% of E. coli isolates were STEC. In addition to our results and also finding of Momtaz et al, 13 Hemmatinezhad et al 14 and Ranjbar et al, 15 simultaneous presences of stx1, stx2, eaeA and ehly virulence factors have also been reported by Franz et al, 17 JayRussell et al 18 and Kabiru et al 19 …”

Validation of a Previously Developed Geospatial Model That Predicts the Prevalence of Listeria monocytogenes in New York State Produce Fields

“…Numerous studies (8)(9)(10)(11)(12)(13)(14)(15)(16)(17)(18)(19)(20)(21) have examined the ecology of foodborne pathogens in agricultural environments, and several (22)(23)(24)(25)(26)(27) have used GIS and geospatial analysis. For example, Chapin et al (26) used GIS to organize and extract remotely sensed data to show that different species of Listeria occupy distinct ecological niches in agricultural and natural environments.…”