Prevalence and Virulence of Salmonella Bacteria Causing Salmonellosis in Post Weaning Pigs at Swine Farms in Bac Giang Province, Vietnam

The release of Salmonella of 256 breeder sows from 20 swine farms in Hiep Hoa district, Bac Giang province, Viet Nam; The medical waste samples were collected in order to determine the prevalence, serotype and virulence of 166 Salmonellabacteria strains isolated from medical waste of post weaning pigs with Salmonellosis. It was found that: Out of the 166 strains studied, the number of serotypes identified included 2 Salmonella weltevreden, 3 Salmonelladublin, 5 Salmonella anatumand Salmonella senftenberg, 6 Salmonella Heidelberg, 9 Salmonella enteritidis, 30 Salmonella typhimurium, 41 Salmonella choleraesuis, and 10 unknown Salmonella serotype. Salmonella weltevreden which bore the encoded gene Stnac counted for 50.0 %; Salmonella dublinand Salmonella heidelberg accounted for 66.6 %; Salmonella typhimuriumaccounted for 73.3 %; Salmonella senftenberg, Salmonellaanatum,and Salmonella unknown accounted for 80.0 %; Salmonella enteritidisaccounted for 88.8 %; Salmonella choleraesuiscarrying the DNA bearing the gene producing Stnac counted for 92.6 %. Salmonelladublinbearing the gene fim A accounted for 33.3 %; Salmonella weltevreden accounted for 50.0 %; Salmonella unknown accounted for 60.0 %; Salmonella typhimuriumand Salmonella heidelberg accounted for 66.6%; Salmonella senftenberg and Salmonella anatum accounted for 80.0 %; Salmonella enteritidisaccounted for 88.8 %; and Salmonella choleraesuis accounted for 92.6 %. Salmonella typhimurium bearing the gene InvA accounted for 26.6 %; Salmonella unknown accounted for 30.0 %; Salmonella heidelberg and Salmonella dublin accounted for 33.3 %; Salmonella choleraesuis accounted for 39.0 %; Salmonella anatumand Salmonella senftenberg accounted for 40.0 %; Salmonella weltevreden accounted for 50.0 %; and Salmonella enteritidis accounted for 66.6 %. Salmonella choleraesuis strains were resistant to nalidixic acid (2.4 %); ciprofloxacin, rifampicin, spectinomycin (7.3 %); ceftazidime, oxytetracycline (9.7 %); nitrofurantoin (12.1 %); trimethoprim-sulfamethoxazole (19.5 %); kanamycin (21.9 %). Salmonella enteritidis strains were resistant to ciprofloxacin, rifampicin, ceftazidime, spectinomycin, nitrofurantoin (11.1 %); trimethoprimsulfamethoxazole, kanamycin (22.2 %). Salmonella typhimurium strains were resistant to nitrofurantoin, nalidixic acid and ceftazidime (3.3%); ciprofloxacin, spectinomycin and rifampicin (6.6 %); trimethoprim-sulfamethoxazole (16.6 %); kanamycin (20.0 %). Keywords: Pig; Salmonella; Bacteria; Virulenc