This paper dealt with the distribution of Salmonella (S) infection on 4 herds in Kyungju and Taegu during the period from May to October 1986. Isolated Salmonella were examined for serotypes, antimicrobial drug resistance and detection of R plasmid.
The results obtained were summarised as followings:
1. Of total 4.622 samples from 4 herds, 67 Salmonella were isolated from 51 samples(1.1%), and their serovar strains were S typhimurium 6, S derby 5, S infantis 4, S bareilly 4, S dublirn 3, S anatum 2, S montevideo 2 and untypable 41.
2. The isolation rate of Salmonella was higher in summer and autumn.
3. Of the 67 strains examined, 45 (67.2%) were resistant to one or more antibiotics, such as ampicillin (Am), cephalothin (Ce), chloramphenicol (Cm), rifampicin (Rf), sulfadimethoxine (Su), and tetracycline (Tc), and higher resistant to Sm (40.2%), Ce (31.3%), Am (23.9%).
4. Of the 45 resistant Salmonella strains, 44 (97.8%) harbored conjugative R plasmids and the transfer frequency of Sm (100%), Ce (95.2%), Tc (91.0%) and Su (80.0%) resistance was much higher than that of the other drug resistance.
5. The most common resistant patterns were 5m, Ce, AmCeCmSmSuTc, and AmCe.
6. In 4 herds, the incidience of drug resistance was 57.7%∼100% and transfer frequency of conjugative R plasmid was 96.1%∼100%.
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