Author : Ngo Nhat Thang

Summary : Rectal fecal samples of 238 dairy cattle from 10 selected farms in Bacthai province, Vietnam, were cultured to detect SALMONELLA. The overall prevalence of SALMONELLA infection derived from sampled farms was 22.58 percent (54/238). Salmonella spp. was three times more frequent in diarrheic (50 percent) than in non-diarrheic cattle (15 percent) and higher in young two-weeks-old (55 percent) than in other age groups. Using infant mouse test, 88 percent (31/35) of SALMONELLA isolates produced enterotoxin. Isolates from all diarrheic cattle were enterotoxin producers, while only 73 percent in nondiarrheic cattle produced enterotoxin. Seventy-seven percent (31/35) SALMONELLA isolates were positive for the heatstable toxin (ST). The proportion of ST-producing SALMONELLA among diarrheic and nondiarrheic cattle was 85 percent, and 66 percent, respectively.