Genetic diversity, antibiotic resistance and biofilm-forming ability of Arcobacter butzleri isolated from poultry and environment from a Portuguese slaughterhouse

The genus Arcobacter is an emerging pathogen associated with several clinical symptoms. This genus is widely distributed and has been isolated from environmental, animal, food and human samples, where poultry is considered the major source. In this study, forty three Arcobacter butzleri strains isolated from poultry and environment of a Portuguese slaughterhouse, were characterized by pulsed field gel electrophoresis (PFGE) and assessed for antimicrobial susceptibility and ability to form biofilms. PFGE patterns obtained using restriction enzymes SmaI and SacII revealed high genetic diversity, with 32 distinct PFGE patterns. Most of A. butzleri isolates presented multiple antimicrobial resistance, exhibiting four different resistance profiles. All 43 isolates were susceptible to gentamicin and 2.3% were resistant to chloramphenicol, in contrast to twenty four (55.8%) that were resistant to ciprofloxacin. Among 36 selected isolates, 26 strains presented biofilm-forming ability, which was dependent on the atmosphere and initial inoculum density.Overall, the results showed that A. butzleri displays a high genetic diversity, and presents resistance to several antibiotics, which together with its biofilm formation ability may represent a potential hazard for foodborne infections and a considerable risk for human health.

► Arcobacter butzleri was isolated from poultry and slaughter environment in Portugal.
► Pulsed field gel electrophoresis patterns revealed high genetic diversity.
► A high percentage of isolates was found to be resistant to several antibiotics.
► A. butzleri adherence ability may have an important role on cross-contamination.