Isolation of a multidrug-resistant Escherichia coli pathotype Stx2:Cnf1:Cnf2:Eae as a potential cause of hemorrhagic diarrhea and secondary septicemia in a dog

Abstract

Escherichia coli is a member of the family Enterobacteriaceae and is a commensal in the intestine of many animals as well as humans. Most strains are of low virulence. A dog developed vomiting and hemorrhagic diarrhea after surgery and died despite treatment. Postmortem examination revealed hemorrhagic gastroenteritis and colitis. A multidrug-resistant E. coli, with virulence factors Shiga-toxin–producing gene, stx2, eae gene, and cytotoxic necrotic factors CNF-1 and CNF-2, was isolated from internal organs. E. coli can easily acquire new genes for virulence factors and antimicrobial resistance as demonstrated by this isolate with characteristics of both enterohemorrhagic E. coli and necrotoxigenic E. coli. In addition, the isolate was resistant to all beta-lactam antibiotics tested, as well as to enrofloxacin by a disk diffusion methodology. Broth-based minimum inhibitory concentration analysis confirmed resistance to amoxicillin (>32 μg/mL), enrofloxacin (>32 μg/mL), fosfomycin (>128 μg/mL), and neomycin (>32 μg/mL). The discovery of such strains is a cause for concern given that E. coli can be shared by companion animals and their human owners.

Fosfomycin Resistance in Bacteria Isolated from Companion Animals (Dogs and Cats)

“…The isolate was MDR and possessed virulence factors for two pathotypes. It was proved to be Fosfomycin-resistant in the MIC test, even though in the disk diffusion test it demonstrated a susceptible phenotype [ 78 ].…”

“…ARGs for Fosfomycin are also not usually screened in molecular assays and, consequently, they are not detected. A characteristic of the limited available data is that only one of the articles included in this review originated from Africa [ 78 ] and the references from Europe come only from three countries (France, Germany, Hungary) [ 49 , 54 , 55 , 60 , 73 , 74 ]. More relevant studies have been conducted in Southeast Asia ( Figure 2 ).…”

“…The MIC and the disk diffusion methods for Fosfomycin have their own specifications and should be evaluated with caution [ 85 ]. Furthermore, in the included studies, bacteria carrying ARGs for Fosfomycin demonstrated a susceptible AST in some cases [ 53 , 67 , 68 ], while there is an ambiguous AST, with an isolate observed to be susceptible by the disk diffusion method and proved to be resistant by the MIC method [ 78 ]. Additionally, the existing clinical breakpoints refer exclusively to human medicine with only a few exceptions [ 86 ], and the clinical trials in companion animals are limited [ 18 ].…”

Enterohemorrhagic Escherichia coli (EHEC) Disrupts Intestinal Barrier Integrity in Translational Canine Stem Cell-Derived Monolayers

“…Focusing specifically on severe EHEC infections, about 10% of patients with infections from Shiga toxin-producing E. coli (STEC) may develop HUS, with a mortality rate of 3 to 5% (29). In canine subjects, severe EHEC infections leading to HUS have been documented, though predominantly in experimental settings or dogs with compromised immunity (4, 5). In our study, the impact of EHEC infection included a modest decrease in TEER, with a reduction of approximately 500 Ω*cm2.…”

“…Although the pathogenicity of EHEC in dogs are relatively mild (3), acute colitis due to EHEC infection, including hemorrhagic diarrhea and HUS similar to humans, has been demonstrated in experimentally infected dogs or critically ill dogs (4, 5). Because of this similarity, there is a growing interest in using dogs as in vivo models for human EHEC infections and as sources of cells and tissues for in vitro models.…”