Use of Bolton broth for selective enrichment and comparative analysis of its performance with direct plating methodology for isolating Campylobacter spp. from chilled chicken carcasses

Abstract

This study aimed at comparing the use of selective enrichment and direct plating for isolating the thermophilic species of Campylobacter spp. from 30 samples of chilled chicken carcasses purchased in supermarkets, marketplaces and slaughterhouses in the Rio de Janeiro city, from July 2009 to July 2010. Chicken carcasses were rinsed out with 400 mL of 1% buffered peptone water for bacteria recovering. Charcoal Cefoperazone Deoxycholate agar and Campy Cefex agar were used for direct plating. Selective enrichment was performed employing Bolton broth in single and double concentrations. The presence of Campylobacter spp. was detected in 21 samples (70%), being 6 (28.6%) from slaughterhouses (3 with State inspection service and 3 without inspection), 8 (38.1%) from supermarkets and 7 (33.3%) from marketplaces. No statistically significant differences were found among the results obtained from different establishments. Of 21 positive samples, 2 (9.5%) were isolated from single Bolton broth and none of them was positive in double Bolton broth. Therefore, the direct plating was considered easier, faster and more cost-effective than the selective enrichment methodology for recovering Campylobacter spp. from chilled chicken carcasses.