Detection and Phylogenetic Characterization of Virulence Genes of Escherichia coli Associated with Canine Urinary Tract Infections in India

Abstract

BACKGROUND: Escherichia coli (E.coli) is one of the most common and important causative bacterium of urinary tract infections (UTIs) in both dogs and humans. OBJECTIVES: This study aimed to identify virulence genes and a phylogenetic group of E. coli isolated from the urine of dogs suffering from UTIs. METHODS: E. coli were isolated from urine of dogs suffering from UTIs and tested for the presence of the virulence genes using conventional polymerase chain reaction (PCR) and sequencing method. On day 60 after immunization, half of the fish in each treatment was challenged intraperitoneally and the re- maining half of fish in the oral receiving bacterin groups were challenged by bath method with 1 LD50 and 1 LC50 of a Y. ruckeri local virulent isolate respectively. RESULTS: Out of a total of 103 samples, 25 were found to be positive for E. coli, of these 20 (80.0%) were identified as aer, 14(56.0%) as pap , 12(48.0%) as sfa, 8(32.0%) as afa, 5(20.0%) as hly and 5(20.0%) as cnf1 genes. None of the isolates carried cnf2 genes. CONCLUSIONS: The study demonstrated a high occurrence of virulence genes. The phylogenetic compar- isons of these gene sequences detected in uropathogenic E. coli isolated from dogs showed high similarity to those present in the urine of humans with urinary tract infection. Phylogenetic comparisons of the virulence genes revealed that hly, sfa , cnf1 and pap matched to group B2, afa to group A and aer to group B2 and D.