AimThis study was conducted to study the coagulase gene-based genetic diversity of Staphylococcus aureus, isolated from different samples of cattle using restriction fragment length polymorphism (RFLP) and their sequence-based phylogenetic analysis.Materials and MethodsA total of 192 different samples from mastitic milk, nasal cavity, and pus from skin wounds of cattle from Military Dairy Farm, Jammu, India, were screened for the presence of S. aureus. The presumptive isolates were confirmed by nuc gene-based polymerase chain reaction (PCR). The confirmed S. aureus isolates were subjected to coagulase (coa) gene PCR. Different coa genotypes observed were subjected to RFLP using restriction enzymes Hae111 and Alu1, to obtain the different restriction patterns. One isolate from each restriction pattern was sequenced. These sequences were aligned for maximum homology using the Bioedit softwareandsimilarity in the sequences was inferred with the help of sequence identity matrix.ResultsOf 192 different samples,39 (20.31%) isolates of S. aureus were confirmed by targeting nuc gene using PCR. Of 39 S. aureus isolates, 25 (64.10%) isolates carried coa gene. Four different genotypes of coa gene, i.e., 514 bp, 595 bp, 757 bp, and 802 bp were obtained. Two coa genotypes, 595 bp (15 isolates) and 802 bp (4 isolates), were observed in mastitic milk. 514 bp (2 isolates) and 757 bp (4 isolates) coa genotypes were observed from nasal cavity and pus from skin wounds, respectively. On RFLP using both restriction enzymes, four different restriction patterns P1, P2, P3, and P4 were observed. On sequencing, four different sequences having unique restriction patterns were obtained. The most identical sequences with the value of 0.810 were found between isolate S. aureus 514 (nasal cavity) and S. aureus 595 (mastitic milk), and thus, they are most closely related. While as the most distant sequences with the value of 0.483 were found between S. aureus 514 and S. aureus 802 isolates.ConclusionThe study, being localized to only one farm, yielded different RFLP patterns as observed from different sampling sites, which indicates that different S. aureus coagulase typeshave a site-specific predilection. Two coa patterns were observed in mastitic milk indicating multiple origins of infection, with 595 bp coa genotype being predominant in mastitic milk. The coa genotypes and their restriction patterns observed in the present study are novel, not published earlier. 514 and 595 coa variants of S. aureus are genetically most related.

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To determine the occurrence and molecular characterization of Shiga toxin-producing E. coli (STEC) and Enteropathogenic E. coli (EPEC) from different domestic animals for serogrouping, virulence factors and their antibiotic resistance from Jammu region. Methodology: Faecal samples were collected from 200 different animals including calves (39), rabbits (24), dogs (38), slaughtered pigs (22), poultry (41), sheep and goat (36). All the 200 strains were screened for the presence of stx1, stx2 and eae genes by m-PCR and screening of confirmed EPEC isolates with respect to their serogroup, virulence factors (bfpA, astA and ecpA genes) by PCR and antibiotic resistance. Results: Of total 200 E. coli isolates, 38 (19.00%) were detected as EPEC and 28 (14.00%) as STEC. 5 (12.82%), 17 (43.58%) isolates from calves and 12 (33.33%), 11 (30.55%) isolates from sheep were found as EPEC and STEC, respectively. In rabbits, pigs and dogs, 6 (25.0%), 10 (45.45%) and 5 (13.15%) isolates were detected as EPEC, respectively. The most predominant EPEC serogroups were O88 (36.84%), O118 (18.42%). All 38 EPEC (100%) isolates carried ecpA gene and 18 (47.36%) isolates carried astA gene. Of 38 EPEC, only 5 (13.15%) isolates from dog carried bfpA gene, therefore considered as typical EPEC and 33 (86.84%) isolates were designated as atypical EPEC. Antimicrobial sensitivity test (AST) of 38 EPEC isolates showed resistance to nalidixic acid (55.26%), kanamycin (42.10%) followed by streptomycin (42.10%), doxycycline hydrochloride (28.94%), ciprofloxacin (13.15%), tetracycline (13.15%). Surprisingly, all the 38 isolates were sensitive to ampicillin.