Escherichia coli and Enterobacteriaceae counts on poultry carcasses along the slaughter processing line, factors influencing the counts and relationship between visual faecal contamination of carcasses and counts: a review
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A literature review was conducted covering the period 2000-2012 to gather information concerning the presence and counts of E. coli and Enterobacteriaceae on carcasses during different stages of the slaughter processing line (review question 1); risk factors that could explain the variability of the counts of the indicator organisms (review question 2) and the relationship between the counts of indicator organisms and visual faecal contamination on carcasses (review question 3). In total, 72 papers, providing pertinent data for the scopes of the search, were collected on poultry. A certain level of variability was evidenced among different studies and some variables like the indicator organism considered, the sampling and analytical methods used, the use of chlorine, the setting where the studies were carried out render the available data barely comparable. In relation to review question 1, the steps of the processing line where a decrease of E. coli was more evident were scalding, washing and chilling; furthermore as regards Enterobacteriaceae counts a decrease was observed at the scalding and washing steps. Considering review question 2, risk factors related to batch and slaughtering process were evaluated. In general when a risk factor was investigated by several studies results were hardly in agreement. Taking into account the slaughter process it is evident that plant features have an influence on indicator bacteria loads but considering each investigated risk factor no reliable conclusions can be drawn. In relation to review question 3, despite the retrieved studies were quite limited, the data obtained suggested that the presence of visible faecal contamination has no predictive value for estimating the microbial quality of the carcasses.