Antimicrobial susceptibility and plasmid analysis of Actinobacillus pleuropneumoniae isolated in Taiwan

Vet Microbiol. 2002 Jan 3;84(1-2):169-77. doi: 10.1016/s0378-1135(01)00459-x.

Abstract

Sixty Actinobacillus pleuropneumoniae (App) strains from pigs in Taiwan were examined. Serotyping revealed that these belonged to serovars 1 (n=53), 2 (n=3), and 5 (n=4). Agar disk diffusion susceptibility testing of the isolates showed 55 (92%) were resistant to three or more antimicrobial agents. Six resistance patterns were observed. Ampicillin-chloramphenicol-flumequine-nalidixic acid-streptomycin-sulfonamide/trimethoprim-tetracycline was the most common multi-resistance pattern. Minimal inhibitory concentration of 14 antimicrobial agents was determined. The isolates were highly susceptible to ceftiofur and trimethoprim in vitro. Isolates were resistant to streptomycin, ampicillin, and nalidixic acid. All isolates were examined for the presence of plasmids using the alkaline lysis method. Forty three (72%) isolates had four plasmid bands with an approximate sizes of 3.5, 4.3, 5.8 and 6.0 kb; 12 (20%) had three bands at 3.5, 4.3 and 5.2 kb, and 5 (8%) had no plasmid bands. Antimicrobial resistance plasmids were detected in resistant strains of App. Three antimicrobial resistance plasmids were transformed into E. coli DH5 alpha. pTMY1 (4.3 kb) encoded a streptomycin kinase and a dihydropteroate synthase; pTMY2 (6.0 kb) encoded ROB-1 beta-lactamase and aminoglycoside 3'-phosphotransferase; pTMY3 (5.2 kb) encoded only ROB-1 beta-lactamase. The 4.3 kb plasmid was sequenced and consisted of 4242 bp with 42.9% GC content. The 4.3 kb plasmid DNA sequence was 98% homologous to a plasmid previously isolated from Pasteurella haemolytica.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Actinobacillus Infections / drug therapy
  • Actinobacillus Infections / microbiology
  • Actinobacillus Infections / veterinary*
  • Actinobacillus pleuropneumoniae / classification
  • Actinobacillus pleuropneumoniae / drug effects*
  • Actinobacillus pleuropneumoniae / genetics
  • Animals
  • Anti-Bacterial Agents / pharmacology*
  • Anti-Bacterial Agents / therapeutic use
  • Base Sequence
  • DNA, Bacterial
  • Drug Resistance, Multiple, Bacterial
  • Microbial Sensitivity Tests / veterinary
  • Molecular Sequence Data
  • Plasmids
  • Pleuropneumonia / drug therapy
  • Pleuropneumonia / microbiology
  • Pleuropneumonia / veterinary*
  • Restriction Mapping
  • Sequence Homology, Amino Acid
  • Serotyping / veterinary
  • Swine
  • Swine Diseases / drug therapy
  • Swine Diseases / microbiology*
  • Taiwan

Substances

  • Anti-Bacterial Agents
  • DNA, Bacterial