Salmonella and Campylobacter Populations of Poultry Carcasses during Slaughter

Introduction: In 2011, the United States Department of Agriculture implemented new performance standards for Salmonella and Campylobacter on young poultry carcasses. This has increased the need for poultry slaughter operations to understand the impact of their processes on the pathogenic profile of carcasses.

Purpose: This study evaluated the incidence of Salmonella and Campylobacter on poultry carcasses during slaughter.

Methods: The processing steps in two poultry slaughter plants (A and B) were analyzed and included: scalding in potable water (PW; 47-54 °C), picking using PW or chlorine (30-40 ppm), New York wash in acidified sodium chlorite (ASC, 817-1039 ppm, 2.45-2.50 pH) or chlorine (40-50 ppm), evisceration including a chlorine wash (30-50 ppm), inside and outside bird wash in chlorine (40-50 ppm), online reprocessing using ASC (930-1045 ppm, 2.36-2.51 pH), hydrochilling in peroxyacids (PA, 10-14 ppm) or chlorine (40-50 ppm), and post-chiller antimicrobial wash (PCAW) with ASC (810-879 ppm, 2.45-2.60 pH). Before and after each step (4 days, 10 samples/day), bacteria were rinsed from carcasses (1 min, 400 ml buffered peptone water solution) and rinsates were analyzed for pathogen incidence (Salmonella and Campylobacter) and counts (Campylobacter). Data were analyzed using a chi-square (incidence) or Tukey’s test (counts) in Minitab with a significance level of α=0.05.

Results: Immediately prior to scalding, carcasses had a Salmonella incidence rate of 100.0 and 20.0% for plants A and B, respectively. After processing, Salmonella incidence was reduced (P < 0.05) to 0.0% for both plants. Processing reduced (P < 0.05) Campylobacter incidence and counts on poultry carcasses from 42.1 to 2.5% and 2.2 ± 0.6 to 1.0 ± 0.0 log CFU, respectively, at Plant A and 95.0 to 26.3% and 3.6 ± 1.1 to 1.2 ± 0.7 log CFU, respectively, at Plant B. In general, individual processing steps effectively or significantly reduced (P < 0.05) Campylobacter on carcasses with scalding having biggest impact on counts (reductions of 0.7 and 1.3 log CFU for Plant A and B, respectively) and PCAW on the incidence (reductions of 27.5% and 26.2% for Plant A and B, respectively).

Significance: These data indicate that current processes, that implement multiple antimicrobial applications and control Salmonella, may need to be modified to control Campylobacter.