This paper deals with the isolation of Salmonella on 3 herds during the period from May 1984 to May 1985. Isolated Salmonella were examined for serotypes, adhesive fimbriae, antibiotic susceptibility and detection of R plasmid.
The results were as follows;
Of total 1505 cattle, 24 Salmonella were isolated from 18 cattle (1.2%) and their serotypes were S. enteritidis (g strains), S. derby(4 strains), S. infantis (1 strain), C₁ group(8 strains), C₂ group(1 strain) and untypable(1 strain).
Twelve strains of Salmonella were isolated from 227 cattle with diarrhea and their serotypes were S. enteritidis(4 strains), S. derby(3 strains), S. infantis(1 strain), C₁ group(3 strains) and untypable(1 strain).
The isolation rate of Salmonella in cattle varied from 1.6 to 0.9% in 3 herds, it was higher in summer and autumn and lower with the age.
Of total 24 strains, 23 were adhesive type 1 fimbriae.
Antibiotic susceptibility test of Salmonella isolated was performed by the agar dilution method, using 9 antibiotics as follows: ampicillin(Am), chloramphenicol(Cm), gentamicin(Gm), kanamycin(Km), nalidixic acid(Na), rifampicin(Rf), streptomycin(Sm), sulfadimethoxine(Su) and tetracycline(Tc). All the strains tested were susceptible to Am, Cm, Gm, Km, Na, Rf and Tc. Of total 24 strains, 23(95.8%) were resistant to Su and 14(58.3%) to Sm.
Of the 23 resistant Salmonella strains, all the strains were found to carry R plasmid. Among them, two strains which had the R plasmid conferring SmSu resistance was transferable at 25℃ only.
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