Broiler carcasses (n = 325) were sampled in a U.S. commercial poultry processing plant during five plant visits from August to October of 2004 at three sites along the processing line: 1) pre-scalding, 2) pre-chilling, and 3) post-chilling. Arcobacter species were recovered from pre-scalded carcasses more frequently (96.8%) than from pre-chilled (61.3%) and post-chilled carcasses (9.6%). For Arcobacter identification, a species-specific multiplex PCR assay showed that A. butzleri was the most prevalent species (79.1%) followed by A. cryaerophilus 1B (18.6%). A. cryaerophilus 1A was found at low levels (2.3%) and A. skirrowii was not isolated at all. Campylobacter was isolated from 92% of pre-scalded carcasses, 100% of pre-chilled carcasses, and 52% of post-chilled carcasses. For Campylobacter speciation, the BAX PCR identified as C. jejuni (87.6%) as the most common species followed by C. coli (12.4%). The genetic diversity of Arcobacter and Campylobacter was analyzed by pulsed field gel electrophoresis (PFGE). Genomic DNA was digested with KpnI from Arcobacter strains and SmaI from Campylobacter strains. A total of 32.8% of Arcobacter isolates belonged to single-isolate groups, while only 2.3% of Campylobacter isolates belonged to this category. The remaining Arcobacter species were distributed among 25 multi-isolate PFGE groups, while Campylobacter species were found in just eight multi-isolate groups. The great majority of Arcobacter (93.7%) and Campylobacter (99.5%) isolates were resistant to one or more antimicrobials. Multiple antimicrobial resistance was observed in 71.8% of the Arcobacter isolates and in 28.4% of the Campylobacter isolates. Of the A. butzleri isolates, 89.9% (n = 125) were resistant to clindamycin, 82% (n = 114) were resistance to azithromycin, and 23.7% (n = 33) were resistant to nalidixic acid. Resistance to tetracycline was very high in C. jejuni and C. coli at 99.5% and 96.3%, respectively. These data suggest significant contamination of Arcobacter and Campylobacter from carcasses from different processing sites in a commercial poultry plant with a high genetic diversity of Arcobacter, and demonstrated resistance in Arcobacter and Campylobacter to common antimicrobial agents.
