SALMONELLA-TYPHIMURIUM ISOLATES FROM APPARENTLY HEALTHY ADULT CATTLE

The prevalence of Salmonella inapparently healthy, cattle, and its dru g sensitivity and other activities were studied. Out of the 143 rectal swabs from apparently healthy cattle tested 4 isolates of Salmonella typhimurium were recovered. All the isolates were sensitive to chloram phenicol, co-trimoxazole, gentamicin, kanamycin, neomycin and streptom ycin. Resistance towards ampicillin and chlortetracycline was showed b y all the Salmonella isolates. The whole culture of all the isolates @ 0.1 ml intraperitoneally caused 80 to 100% mortality in the inoculate d mice, while the cell-free culture supernatant of the isolates by the same dose and route killed 60 to 80% of the inoculated mice. The wash ed viable cells containing approximately 100 bacilli/0.1 ml when injec ted by the same route did not cause any mortality of the inoculated mi ce within the observation period of 7 days except 1 strain which kille d only 1 (20%) of the 5 mice tested. The heat-treated (60-degrees-C, 3 0 min) cell-free culture supernatant of none of the isolates caused an y gut reaction of accumulation of fluid in rabbit-ligated ileal loop, while the non-treated preparations of the 3 isolates caused marked gut reaction. The non-treated cell-free culture supernatants of the 3 ent erotoxic strains also produced marked hyperaemia and swelling on the r abbit skin.