Bacterial Causes of Hemorrhagic Gastroenteritis in Dogs and Cats with Detection of Some Virulence and β-lactamase Resistance Genes in Escherichia coli and Salmonella by Multiplex PCR

Abstract

Hemorrhagic Gastroenteritis (HGE) is a life-threatening disease caused by bacteria or viruses or endoparasites or irritant drugs or food allergies. Out of 202 sampled animals, the total bacterial isolates were 104. The identified bacterial isolates were 46 (44.23%) E. coli, 9 (8.65%) Klebsiella, 5 (4.80%) C. perfringens, 22 (21.15%) Proteus spp., 3 (2.88%) Salmonella spp., 3 (2.88%) Shigella spp. and 4 (3.84%) Pseudomonas aeruginosa, 4 (3.84%) Enterobacter species, 2 (1.92%) Citrobacter species, 2 (1.92%) Providencia rettgeri, 1 (0.96%) Hafnia species, 1 (0.96%) Serratia liquefaciens, 1 (0.96%) C. bifermentans and 1 (0.96%) C. putrefaciens. EHEC (12/26, 46.15%), EPEC (9/26, 34.61%) and ETEC (4/26, 15.38%) strains were detected by E. coli serotyping. Salmonella isolates were serotyped as Salmonella Typhimurium, S. Heidelberg, and S. Infantis. E. coli isolates from dogs were resistant to amoxicillin/clavulanic acid, cephalexin, ceftriaxone, trimethoprim/sulphamethoxazole, tetracycline, and erythromycin. Feline E. coli isolates had moderate resistance to amoxicillin/clavulanic acid, trimethoprim/ sulphonamides, and tetracycline. Salmonella isolates were highly resistant to amoxicillin/clavulanic acid, cephalexin, trimethoprim/sulphamethoxazole, tetracycline, and erythromycin. stx1 and stx2 E. coli virulence genes were detected in 80% and 60% of tested E. coli isolates, respectively while S. Typhimurium was positive for invA, hilA, and fimH virulence genes and S. Heidelberg was positive for invA and fimH genes. blaTEM and blaCTX-M1 β-lactamase resistance genes were detected in 60% and 20% of tested E. coli isolates, respectively. Salmonella Typhimurium was positive for blaCMY-1 and blaOXA-2 genes, Salmonella Heidelberg was positive for the blaCMY-1 gene. In conclusion, E. coli, Salmonella, C. perfringens, Klebsiella were major bacterial causes of HGE in dogs and cats. Additionally, E. coli and Salmonella isolated from companion animals can carry multidrug resistance genes encoding for extended-spectrum β-lactamases.