Antimicrobial susceptibility of Actinobacillus pleuropneumoniae, Escherichia coli, and Salmonella choleraesuis recovered from Taiwanese swine.
Minimum inhibition concentrations (MICs) were determined for ampicillin, ceftiofur, cephalothin, chloramphenicol, enrofloxacin, gentamicin, lincomycin, lincospectin (lincomycin/spectinomycin), neomycin, premafloxacin, spectinomycin, sulfamethoxazole/trimethoprim, and tetracycline against a total of 180 isolates of Actinobacillus pleuropneumoniae, Escherichia coli, and Salmonella choleraesuis (60 each) clinically isolated from pigs on farms in Taiwan from 1994 to 1996. No more than 3 isolates per farm were used. Ceftiofur had the highest activity in vitro against isolates of A. pleuropneumoniae, E. coli, and S. choleraesuis, with MIC90 values of 0.03, 2, and 1 microg/ml, respectively. Premafloxacin was highly active against isolates of A. pleuropneumoniae, E. coli, and S. choleraesuis, with MIC90 values of 2, 8, and 0.5 microg/ml, respectively, which were lower than those with enrofloxacin (MIC90 8, 32, and 2 microg/ml, respectively). Neomycin was moderately active against A. pleuropneumoniae and E. coli, with MIC90 values of 8 and 64 microg/ml, respectively, but was inactive with S. choleraesuis. Gentamicin showed high activity against A. pleuropneumoniae (MIC90 of 2 microg/ml) but was only moderately active with E. coli and S. choleraesuis (MIC90 of 64 and 32 microg/ml). Cephalothin was highly active against isolates of A. pleuropneumoniae (MIC90 of 1 microg/ml) but was inactive with E. coli (MIC90 of 128 microg/ml). Lincomycin had moderate activity (MIC90 of 32 microg/ml) against A. pleuropneumoniae. Chloramphenicol, lincomycin, and tetracycline were inactive with E. coli and S. choleraesuis (MIC90 > 128 microg/ml). In conclusion, ceftiofur and premafloxacin were highly active against isolates of A. pleuropneumoniae, E. coli, and S. choleraesuis, enrofloxacin and gentamicin were highly to moderately active; cephalothin was highly active against A. pleuropneumoniae and moderately active against S. cholearesuis; chloramphenicol, lincomycin, and tetracycline were active only with A. pleuropneumoniae; neomycin was moderately active against A. pleuropneumoniae and E. coli. The other antimicrobials tested were inactive.
Chang
Chao-Fu
CF
Department of Veterinary Medicine, National Taiwan University, Taipei.
Chang
Lin-Chu
LC
Chang
Yung-Fu
YF
Chen
Michael
M
Chiang
Tai-Sheng
TS
D000189:Actinobacillus Infections / Q000188:drug therapy / Q000662:veterinary; D016977:Actinobacillus pleuropneumoniae / Q000187:drug effects* / Q000302:isolation & purification / Q000472:pathogenicity; D000818:Animals; D000900:Anti-Bacterial Agents / Q000494:pharmacology*; D004926:Escherichia coli / Q000187:drug effects* / Q000302:isolation & purification / Q000472:pathogenicity; D004927:Escherichia coli Infections / Q000188:drug therapy / Q000662:veterinary; D008826:Microbial Sensitivity Tests; D012475:Salmonella / Q000187:drug effects* / Q000302:isolation & purification / Q000472:pathogenicity; D012481:Salmonella Infections, Animal / Q000188:drug therapy; D013552:Swine; D013553:Swine Diseases / Q000188:drug therapy* / Q000382:microbiology*
D000900:Anti-Bacterial Agents