The activities of ceftiofur, penicillin, enrofloxacin, florfenicol, tetracycline, tilmicosin, and tulathromycin against respiratory pathogens (Pasteurella multocida, Streptococcus suis, and Actinobacillus pleuropneumoniae) recovered from pigs across the United States and Canada between 2001 and 2010 were investigated as part of an on-going, long-term veterinary antimicrobial susceptibility surveillance program.
A total of 1097 Actinobacillus pleuropneumoniae, 2389 Pasteurella multocida, and 2617 Streptococcus suis isolates recovered from diseased or dead swine from North America over a 10-year period were tested for in vitro susceptibility to antimicrobial agents approved for treatment of swine respiratory disease (SRD). Clinical and Laboratory Standards Institute standardized methods were used to determine the minimum inhibitory concentrations (MICs) of ceftiofur, enrofloxacin, florfenicol, penicillin, tetracycline, tilmicosin, and tulathromycin.
This report provides the first extensive survey of the antimicrobial susceptibility of major SRD pathogens isolated from swine across the United States and Canada during the years 2001 to 2010. The data show that, over those 10 years, A pleuropneumoniae and P multocida remained susceptible to ceftiofur, enrofloxacin, florfenicol, tilmicosin, and tulathromycin, and S suis remained susceptible to ceftiofur, enrofloxacin, and florfenicol. Low penicillin MIC values for P multocida and S suis and higher MIC values for A pleuropneumoniae were also seen. Most isolates of all three organisms were resistant to tetracycline over the 10 years of the survey.
The data presented in this report, especially those data that show that there has been some increase in MICs of important antimicrobial agents, should serve to underscore the importance of prudent use of these drugs when treating SRD (and other infections). Careful stewardship may allow for effective use of these drugs for many years. On-going surveillance of the in vitro susceptibility of these SRD pathogens will continue to be an important component in antimicrobial stewardship. Monitoring antimicrobial susceptibility among swine pathogens over time provides valuable information about changes which may be occurring in the antimicrobial susceptibility of these organisms and is an important tool in effective antimicrobial therapy.
Portis E, Lindeman C, Johansen L, et al. Antimicrobial susceptibility of porcine Pasteurella multocida, Streptococcus suis, and Actinobacillus pleuropneumoniae from the United States and Canada, 2001 to 2010. J Swine Health Prod. 2013;21(1):30–41.