Evaluation of carcass scraping to enumerate bacteria on prechill broiler carcasses

Analyses of the Bacterial Contamination on Belgian Broiler Carcasses at Retail Level

Broilers are not equally exposed to bacterial contamination during rearing and processing, resulting in areas with different bacterial communities on carcasses at retail. The determination of these communities is also affected by the examination methods applied. The present study aimed to assess the bacterial communities on neck, breast, and back skin on broiler carcasses at retail through classical International Organization of Standardization based isolation methods combined with identification by matrix-assisted laser desorption ionization time-of-flight mass spectrum (MALDI-TOF MS) and 16S amplicon sequencing. Twelve commercially and eight organically reared broilers slaughtered in four slaughterhouses were examined. Significantly higher anaerobic bacterial counts were observed on the neck skin than on the breast and back skin. By the combination of cultivation and amplicon sequencing, remarkable shifts in bacterial communities were determined on the breast and back skin, but not on the neck skin. Although the aerobic bacteria contamination levels were not different between the areas, different bacterial communities were observed. The impact of the slaughterhouse to the overall microbial composition was rather small. Organically reared broilers had unique bacterial communities. In conclusion, compared to the breast skin, the neck, and back skin had a larger potential for bacterial spoilage, in particular when anaerobic storage conditions are applied. The distribution of bacteria on the different areas could be related to the contamination during slaughter as well as the bird-rearing methods.

Numbers of Salmonella recovered by sponge or low volume whole carcass rinse sampling of inoculated commercial turkey carcasses

Processed turkey carcasses are sampled for Salmonella via sponge sampling, whereas broilers are sampled via whole carcass rinses. Because different sampling methods have been reported to produce different results, sponge sampling and whole carcass rinsing (WCR) were performed on turkey hen carcasses inoculated with a known amount of nalidixic acid-resistant Salmonella enterica serovar Enteritidis. Five turkey hen carcasses were collected from the shackle line in a commercial processing plant in each of 4 replicate trials. Carcasses were placed in a cooler with a small amount of ice and transported to the laboratory for approximately 1.5 h. Salmonella inoculum was applied by spreading 0.5 mL on the back and 0.5 mL on the thigh. After 10 min, the carcasses were sampled via a premoistened 4×8-cm sponge, swiping 10 times vertically and 10 horizontally on the back, and then repeating the same sequence on the thigh using a 10×5-cm template. After sponge sampling carcasses were placed in a clean plastic bag, 200 mL of buffered peptone was added, and bags were manually shaken for 60 s for a low volume whole carcass rinse (WCR). Liquid from stomached sponges and from WCR rinsate was serially diluted in 0.85% saline and plated onto Brilliant Green agar with sulfapyridine containing 200 ppm of nalidixic acid. Plates were incubated at 37°C for 24 h and colonies indicative of Salmonella were counted and transformed from cfu/mL to log cfu/cm2. The low volume WCR recovered significantly more Salmonella than sponge sampling in trial 3 (log 3.1 vs. 2.3, respectively) and trial 4 (log 3.1 vs. 2.2, respectively). No differences were observed in trials 1 and 2 due to sample method. Low volume WCR is equal to or more effective than sponge sampling for recovering inoculated Salmonella from turkey carcasses.