Survival of Campylobacter jejuni in frozen chicken meat and risks associated with handling contaminated chicken in the kitchen

Most Campylobacter infections in humans are sporadic cases, often connected to private households. Chicken meat is believed to be the main source of human exposure to Campylobacter and there are significant risks of cross-contamination when handling Campylobacter-contaminated chicken in the kitchen. One post-harvest pre-ventive measure to reduce Campylobacter concentrations on chicken meat is freezing. This study examined survival of different sequence types of C. jejuni during freezing and risk factors during handling of C. jejuni-contaminated chicken meat in the kitchen. Chicken fillets were artificially contaminated before freezing with two different sequence types of C. jejuni (ST-257 and ST-918), at concentrations in the meat of 4.1 log10 CFU/g (low) and 5.3 log10 CFU/g (high). Risk factors in the kitchen were assessed by swabbing gloves before and after washing, to simulate hands before and after washing. Utensils such as scissors and forceps used for cutting were also sampled, while a cutting board was sampled twice to simulate before and after wiping.The greatest decrease in Campylobacter concentrations in the freezer occurred in the first four days and the decrease then flattened off. After 49 days in the freezer, concentrations on meat contaminated with high and low levels of ST-257 decreased by 2.0 log10 CFU/g and 1.5 log10 CFU/g, respectively, while concentrations on chicken meat contaminated with a high and low level of ST-918 decreased by 1.0 log10 CFU/g and 0.7 log10 CFU/ g, respectively. Campylobacter was isolated from all simulated environmental samples. The highest load in the environment of both sequence types was unwashed gloves and the first sampling of the unwiped cutting board. Transfer from gloves and the cutting board was lower after washing/wiping, but high concentrations (>= 2 log10 CFU/mL rinse fluid) of Campylobacter persisted for all samples contaminated with ST-918 and for 18 of 20 samples contaminated with ST-257.In conclusion, there are differences between Campylobacter sequence types in their ability to withstand freezing stress and Campylobacter remaining on hands after washing and on cutting boards after wiping is a likely source of cross-contamination in the kitchen

Assessment of ATP-Bioluminescence and Dipslide Sampling to Determine the Efficacy of Slaughterhouse Cleaning and Disinfection Compared with Total Aerobic and<i> Enterobacterales</i> Counts

Inadequate cleaning and disinfection (C&D) in slaughterhouses can cause bacterial contamination of meat, resulting in foodborne disease and reduced meat quality. Different methods for monitoring the efficacy of C&D procedures are available, but few studies have assessed their reliability. This study examined C&D efficacy in slaughterhouses and evaluated the diagnostic performance of methods for measuring surface hygiene.One red meat and one poultry slaughterhouse in Sweden were each visited on six occasions before and six occasions after C&D. Sampling points were sampled with: swabbing and plating for total aerobic bacteria (TAB) and Enterobacterales (EB); dipslides for total viable count; and ATP-bioluminescence tests. To evaluate the diagnostic performance of the dipslide and ATP-bioluminescence methods, the results were compared with (TAB) as a reference.In total, 626 samples were collected. For the majority of samples, TAB was lower after than before C&D and EB were mainly detected before C&D, indicating C&D efficacy. Greater reductions in mean TAB were observed in processing areas (2.2 and 2.8 log CFU/100 cm2 in red meat and poultry slaughterhouse, respectively) than in slaughter areas (1.3 log CFU/100 cm2 in both slaughterhouses). Approximately half of all samples were assessed as non acceptably clean (52% for red meat and 46% for poultry slaughterhouse) according to previously published thresholds. Critical food contact surfaces that were insufficiently cleaned and disinfected were plucking fingers, shackles, and a post-dehairing table. Cleaning and disinfection of drains and floors were inadequate.The ATP-bioluminescence method showed low specificity compared with the reference (TAB) in both the red meat (0.30) and poultry slaughterhouses (0.64). The sensitivity of dipslides was low (0.26) in the red meat slaughterhouse compared with TAB. A combination of ATP-bioluminescence and dipslides could provide more accurate estimates of C&D efficacy

Reducing Campylobacter jejuni, Enterobacteriaceae, Escherichia coli, and total aerobic bacteria on broiler carcasses using combined ultrasound and steam

Campylobacteriosis is the most frequently reported foodborne illness in Europe and many other parts of the world. Campylobacter can colonize the intestines of broilers, mostly in large amounts. Broilers are usually slaughtered in a high-speed automated system that could cause rupture of the intestines during evisceration, resulting in contamination of carcasses with intestinal bacteria like Campylobacter. This study evaluated the combined effects of ultrasound and steam (SonoSteam) on naturally contaminated chicken carcasses at a large-scale abattoir in Sweden. Ultrasound at 30 to 40 kHz and steam at 84 to 85°C or 87 to 88°C were used at slaughter, with a line speed of 18,000 birds per hour. The amounts of Campylobacter spp., Enterobacteriaceae, Escherichia coli, and total aerobic bacteria on neck skins from 103 chicken carcasses, sampled before and after treatment by ultrasound-steam, were analyzed. Campylobacter spp. were quantified in 58 (56%) of the neck skins, from birds belonging to four of the seven flocks represented. All 58 isolates were identified as Campylobacter jejuni. After the ultrasound-steam treatment, the mean reductions in C. jejuni, Enterobacteriaceae, E. coli and total aerobic bacteria were 0.5 ± 0.8, 0.6 ± 0.6, 0.5 ± 0.6, and 0.4 ± 0.7 log CFU/g, respectively. No significant differences in reduction between the two different treatment temperatures were observed for any of the bacteria. Although the bacterial reductions were significant, large amounts of bacteria remained on the carcasses after treatment. Further studies are needed to identify optimal measures at slaughter to reduce food spoilage bacteria and pathogenic bacteria, which should be considered in a One Health perspective

Assessment of ATP-Bioluminescence and Dipslide Sampling to Determine the Efficacy of Slaughterhouse Cleaning and Disinfection Compared with Total Aerobic and Enterobacterales Counts

Inadequate cleaning and disinfection (C&D) in slaughterhouses can cause bacterial contamination of meat, resulting in foodborne disease and reduced meat quality. Different methods for monitoring the efficacy of C&D procedures are available, but few studies have assessed their reliability. This study examined C&D efficacy in slaughterhouses and evaluated the diagnostic performance of methods for measuring surface hygiene.One red meat and one poultry slaughterhouse in Sweden were each visited on six occasions before and six occasions after C&D. Sampling points were sampled with: swabbing and plating for total aerobic bacteria (TAB) and Enterobacterales (EB); dipslides for total viable count; and ATP-bioluminescence tests. To evaluate the diagnostic performance of the dipslide and ATP-bioluminescence methods, the results were compared with (TAB) as a reference.In total, 626 samples were collected. For the majority of samples, TAB was lower after than before C&D and EB were mainly detected before C&D, indicating C&D efficacy. Greater reductions in mean TAB were observed in processing areas (2.2 and 2.8 log CFU/100 cm2 in red meat and poultry slaughterhouse, respectively) than in slaughter areas (1.3 log CFU/100 cm2 in both slaughterhouses). Approximately half of all samples were assessed as non acceptably clean (52% for red meat and 46% for poultry slaughterhouse) according to previously published thresholds. Critical food contact surfaces that were insufficiently cleaned and disinfected were plucking fingers, shackles, and a post-dehairing table. Cleaning and disinfection of drains and floors were inadequate.The ATP-bioluminescence method showed low specificity compared with the reference (TAB) in both the red meat (0.30) and poultry slaughterhouses (0.64). The sensitivity of dipslides was low (0.26) in the red meat slaughterhouse compared with TAB. A combination of ATP-bioluminescence and dipslides could provide more accurate estimates of C&D efficacy