Occurrence of antimicrobial resistance among bacterial pathogens and indicator bacteria in pigs in different European countries from year 2002 – 2004 : the ARBAO-II study
Background: The project "Antibiotic resistance in bacteria of animal origin – II" (ARBAO-II) was
funded by the European Union (FAIR5-QLK2-2002-01146) for the period 2003–05. The aim of this
project was to establish a program for the continuous monitoring of antimicrobial susceptibility of
pathogenic and indicator bacteria from food animals using validated and harmonised
methodologies. In this report the first data on the occurrence of antimicrobial resistance among
bacteria causing infections in pigs are reported.
Methods: Susceptibility data from 17,642 isolates of pathogens and indicator bacteria including
Actinobacillus pleuropneumoniae, Streptococcus suis and Escherichia coli isolated from pigs were
collected from fifteen European countries in 2002–2004.Results: Data for A. pleuropneumoniae from infected pigs were submitted from five countries. Most
of the isolates from Denmark were susceptible to all drugs tested with the exceptions of a low
frequency of resistance to tetracycline and trimethoprim – sulphonamide.
Data for S. suis were obtained from six countries. In general, a high level of resistance to
tetracycline (48.0 – 92.0%) and erythromycin (29.1 – 75.0%) was observed in all countries whereas
the level of resistance to ciprofloxacin and penicillin differed between the reporting countries.
Isolates from England (and Wales), France and The Netherlands were all susceptible to penicillin.
In contrast the proportion of strains resistant to ciprofloxacin ranged from 12.6 to 79.0% (2004)
and to penicillin from 8.1 – 13.0% (2004) in Poland and Portugal.
Data for E. coli from infected and healthy pigs were obtained from eleven countries. The data reveal
a high level of resistance to tetracyclines, streptomycin and ampicillin among infected pigs whereas
in healthy pigs the frequency of resistance was lower.
Conclusion: Bacterial resistance to some antimicrobials was frequent with different levels of
resistance being observed to several antimicrobial agents in different countries. The occurrence of
resistance varied distinctly between isolates from healthy and diseased pigs, with the isolates from
healthy pigs generally showing a lower level of resistance than those from diseased pigs.
The study suggests that the choice of antimicrobials used for the treatment of diseased animals
should preferably be based on knowledge of the local pattern of resistance