Isolation, biological charateristic and antisera determination of Salmonella spp in pork in Lang Son province

Abstract

The result of isolation and determination of the biological characteristics and antisera groups
of Salmonella spp. in pork in Lang Son province indicated that out of 90 pork samples collecting
in Lang Son (Gieng Vuong, Chi Lang, Dong Kinh pork retail markets), there were 12.22% of
samples contaminated with Salmonella spp. Of which, the highest contamination rate was in Chi
Lang market (16.67%), followed by Dong Kinh market (13.33%) and the lowest contamination
rate was in Gieng Vuong market (6.67%). The Salmonella contamination rate of pork increased
by the time after slaughter and seasons from winter to summer. The result of testing susceptibility
with antibiotics of 6 isolated bacteria strains indicated that the susceptible rate of bacteria strain
with ciprofloxacine was 83.33%, with enrofloxacine was 66.6%, with norfloxacine was 50%. All
of isolates resisted with tetracycline, and they were the high virulent strains, killing 100% of the
experimental animals within 24 – 48 hrs after injection. The isolates carried all the biological and
chemical characteristics of Salmonella bacteria genus, and the strains were determined, such as:
5 strains belonged to S. typhimurium (45.45%); 3 strains belonged to S. welteveden (27.27%); 2
strains belonged to S. anatum (18.18%) and 1 strain belonged to S. schlleissheim (9.09%)