Antibiotic susceptibility of Haemophilus pleuropreumoniae and Pasteurella multocida isolates from swine.

Molecular distribution of ROB-1 beta-lactamase in Actinobacillus pleuropneumoniae

“…An overview of ampicillin susceptibility among 139 A. pleuropneumoniae isolates revealed less ampicillin resistance (42%) than did earlier studies done in Canada (Qudbec), the United States, and other countries (2,7,(17)(18)(19)24 on three kinds of plasmid: the small and very common 2.6-kb plasmid; the 5.5-kb plasmid, like pVM105 from A. pleuropneumoniae SD1; and a 6.8-kb plasmid. In other members of the family Pasteurellaceae, the blaROB1 gene was found on a 2.6-kb plasmid from P. multocida and on 4.4-kb Rrob from H. influenzae, the prototype for ROB-1 ,B-lactamase.…”

“…The ampicillin resistance of A. pleuropneumoniae is presumably increasing in Quebec (Canada), as demonstrated by susceptibility studies which showed that 53% of isolates were resistant in 1981 and that 74% were resistant in 1986 (24). In Canada (Ontario), the United States (South Dakota and Iowa), Italy, and Japan, more than 80% of isolates were found susceptible to ampicillin (2,7,(17)(18)(19). Plasmid-mediated ampicillin resistance due to a P-lactamase was first described in A. pleuropneumoniae by Hirsh et al in 1982, and the bla gene was found associated with pVM105 (5.3 kb) (3).…”

Drug Resistance and R Plasmids in Pasteurella multocida Isolates from Swine

“…There have been only a few reports (5,15,19) on drug susceptibility in porcine P. multocida isolates. We previously reported that most of P. multocida isolates in 1979 were antibiotic-susceptible because of poor drug selection pressure in bacteria in respiratory tracts of swine (14) whereas most of Escherichia coli isolates were multiple drug-resistant and R plasmid-bearing (16).…”

“…Antimicrobial treatment is still commonly used to control these diseases and has been compromised due to the emergence of drug-resistant strains. There have been only a few reports on drug susceptibility in P. multocida isolates from swine (5,15,19). This paper describes drug resistance and partial characterization of R plasmids in porcine P. multocida isolates.…”

Morphological Changes and Lysis Induced by β-Lactams Associated with the Characteristic Profiles of Affinities of Penicillin-Binding Proteins in Actinobacillus pleuropneumoniae

“…This pathogen has distributed around the world, and ␤-lactam-resistant strains that can produce ROB-1 ␤-lactamase have been isolated in some countries (9,17). But in Japan, the resistant strains have been observed only in a small percentage of total isolates (1,25,29).…”