Prevalence and quantification of Salmonella contamination in raw chicken carcasses at the retail in China

The quantitative contamination load of Salmonella in raw chicken carcasses at the retail level in six provinces and cities of China was determined within 1595 carcasses over 12 consecutive months. The overall Salmonella contamination rate was 41.6% and the median load of those contaminated was 4.6 MPN/100 g with 1.8 MPN/100 g as the 25th percentile and 18.0 MPN/100 g as the 75th percentile. There were significant variations in prevalence among carcasses sampled either in different provinces or sampling months. Carcasses collected in August had not only the highest prevalence of contamination (55.8%), but also the highest median (14.0 MPN/100 g) and 75th percentile load (120.0 MPN/100 g) values compared to January with lowest prevalence (26.5%), median (1.5 MPN/100 g) and 75th percentile load (7.6 MPN/100 g). The chilled (55.1%) stored carcasses was significantly higher in prevalence than those frozen (33.5%) and those freshly slaughtered (28.3%), those unpackaged (45.1%) was more likely to be contaminated with Salmonella than those packaged (37.4%). The present study revealed the widely prevalent Salmonella contamination among retail carcasses, indicating a strong potential of the cross-contamination occurred before and/or at the retail level. The study also provided quantitative data for a risk assessment evaluating potential intervention methods to reduce the risk of salmonellosis by consuming chicken meat of Chinese origin.     

Potential of Escherichia coli as a surrogate indicator for postchill broiler carcasses with high Campylobacter counts

Surrogating Campylobacter contamination level in broiler carcasses with other bacterial indicators, used to evaluate the hygienic status of the slaughterline operations, might be stimulation to the broiler meat industry to improve control of Campylobacter during slaughter. Theoretically, Escherichia coli might have some practical merits as a potential indicator for carcasses contaminated with Campylobacter. This study investigates the correlation between the counts of E. coli and Campylobacter in 231 postchill broiler carcasses. The impact of setting a process hygiene target based on E. coli counts on reducing the frequency of carcasses contaminated with Campylobacter at level of ≥3 log₁₀ CFU/g was also investigated. Almost half (48.9% (46/94)) of the carcasses with enumerable Campylobacter (≥1 log₁₀ CFU/g) had E. coli counts between 3 and 4 log₁₀ CFU/g. In addition, 54.8% (17/31) of the carcasses contaminated with Campylobacter of ≥3 log₁₀ CFU/g were correlated with E. coli count range of ≥3 & <4 log₁₀ CFU/g. A theoretical scenario assuming that hygiene and processing measures could allow achieving a target for E. coli that not exceeding 3 log₁₀ CFU/g showed a parallel impact on Campylobacter contamination in broiler carcasses. In such scenario, the overall number of Campylobacter-positive carcasses could be dropped from 40.6% to 12.5%; in addition, 80.6% (25/31) of the carcasses contaminated with Campylobacter of ≥3 log₁₀ CFU/g could be eliminated. Findings from this study reveal that a hygiene target based on E. coli count could be used as an indirect sanitary tool for reducing the level of Campylobacter contamination in postchill broiler carcasses.     

Quantitative estimation of Campylobacter cross-contamination in carcasses and chicken products at an abattoir

This study aimed to investigate Campylobacter contamination in carcasses and chicken products derived from a Campylobacter-negative flock when the flock is slaughtered immediately after a Campylobacter-positive flock. The first 2 flocks slaughtered on 10 different dates were investigated at an abattoir. Eighteen of the 20 flocks tested were positive for Campylobacter. A Campylobacter-negative flock was slaughtered immediately after a Campylobacter-positive flock on only 1 of the 10 slaughter dates. In this case, Campylobacter was detected in the carcasses and chicken products originating from the Campylobacter-negative flock, and all the flaA genotypes of these isolates were identical to those present in the caecal contents, carcasses, and chicken products from the Campylobacter-positive flock. The Campylobacter concentrations in the products originating from the Campylobacter-negative flock were: close to the enumeration limit (1.7 log₁₀ cfu/carcass) in the carcass samples; and below the enumeration limit (2.0 log₁₀ cfu/g) in the liver samples. The mean Campylobacter concentrations in the carcasses and liver products originating from the 18 Campylobacter-positive flocks were 3.8 log₁₀ cfu/carcass and 2.6 log₁₀ cfu/g, respectively. While 91% (246/270) of chicken products originating from Campylobacter-positive flocks were positive for Campylobacter, chicken products originating from the remaining Campylobacter-negative flock were free from Campylobacter cross-contamination by slaughter prior to a Campylobacter-positive flock. These results prove that slaughtering Campylobacter-negative flocks does not introduce Campylobacter into the abattoirs and indicate that although carcasses and chicken products originating from the Campylobacter-negative flock were cross-contaminated with Campylobacter from the Campylobacter-positive flock slaughtered immediately before, the Campylobacter contamination levels were lower than those in carcasses and chicken products from Campylobacter-positive flocks. Based on these findings, the reduction of Campylobacter prevalence in broiler flocks should be taken as an effective control measure for preventing introduction of Campylobacter into abattoirs and consequently for reducing Campylobacter prevalence in chicken products in addition to the good hygienic practice at abattoirs and logistic slaughter.     

A risk assessment of salmonellosis linked to chicken meals prepared in households of China

A quantitative microbiological risk assessment model was used to quantify the risk of salmonellosis caused by bacterial growth and cross-contamination of chicken meals prepared in households of China. Chinese data on initial loads of Salmonella in chicken carcasses sold at retail, storage time and handling of raw chicken meat in household kitchens and confirmatory transfer rates of Salmonella among different kitchen objects were collected. Only one third of Chinese families in our sample separated the cutting board between raw and ready-to-eat foods. The cross-contamination of ready-to-eat foods from chicken meals via the cutting board, the knife and cooks’ hands increased the frequency of pathogen ingestion and the risk of salmonellosis. A significant decrease in the risk of salmonellosis could be achieved by reducing the cross-contamination when handling raw chicken meat and ready-to-eat foods. Decreasing the prevalence of Salmonella contamination to 8.8% or removing chicken carcasses with contamination densities higher than 100 MPN/100 g at retail was less effective. Using transfer rates of Salmonella from raw chicken meat to the wooden cutting board instead of that from references, a statistically higher risk of salmonellosis per serve due to the cross-contamination in households was observed. The present study validated values of hygiene practices in China to reduce the risk of salmonellosis from contaminated raw chicken meat at retail. Deliberate surveys for cooking behaviors and transfer rates of Salmonella from and to different objects including wooden cutting boards were needed.     

Reduction of Campylobacter jejuni counts on chicken meat treated with different seasonings

To analyze the potential of various seasoning combinations in reducing Campylobacter jejuni counts on fresh chicken meat, fresh chicken drumstick samples were inoculated with a mixture of two C. jejuni strains at log 4–5 CFU/g and subsequently treated with six different seasonings. After addition as a dry powder to the meat’s surface, all seasoning combinations adsorbed water from the meat and formed a gel on the meat’s surface. The samples were placed in individual packages containing a modified gas atmosphere (N₂ 80% and CO₂ 20%) and stored at 4 °C for seven days and C. jejuni counts in CFU/g were determined at the beginning, after 15 min, 1 h, 1 day and 7 days. The most effective seasoning combination contained, among other ingredients and food additives, sodium lactate and potato protein fractions; it reduced counts by mean 1.52 to 1.66 log CFU/g in seven days. The other seasoning combinations without potato protein fractions decreased counts in the range of mean 1.05 to 1.16 log CFU/g; simultaneously, the counts in control meat samples decreased by mean 0.21 log CFU/g. The death rate estimates after 1 h storage was in the range of ?0.25 log CFU/g/h to ?0.34 log CFU/g/h.In conclusion, various combinations of seasonings decreased the counts of C. jejuni, with the highest C. jejuni death rate during the first hour and further minor reductions in C. jejuni counts with additional storage time. These types of treatments may decrease human exposure to Campylobacter from fresh poultry meat.     

Microbiological evaluation of fresh-cut organic vegetables produced in Zambia

This study was undertaken to assess the microbiological quality of fresh-cut organic vegetables produced in Zambia. Fresh-cut organic mixed vegetables and green beans produced in Zambia were analysed for aerobic plate counts, coliforms, Enterobacteriaceae, Escherichia coli, Bacillus cereus, Clostridium perfringens, Listeria monocytogenes, Salmonella spp., Staphylococcus aureus, and yeast and mould counts. The study included 160 samples for most of the parameters. The vegetables were grown on farms meant primarily for the export market. The vegetables were treated/washed with 150 μg ml⁻¹ chlorine solution at the processing plant prior to sampling. The aerobic plate count ranged between 3 log₁₀ and 9.7 log₁₀ CFU/g, with the highest count recorded for green beans. The largest grouping (26.1%) of vegetable samples fell between 3 and 4 log₁₀ CFU/g. Coliform counts were between 1.0 log₁₀ and 7.7 log₁₀ CFU/g. The highest incidence level was 31.4% for total coliform counts between 3 log₁₀ and 4 log₁₀ CFU/g. E. coli was only detected on mixed vegetables in the range of 0.6 log₁₀ to 3 log₁₀ CFU/g, while Enterobacteriaceae counts ranged between 1.6 log₁₀ and 9.8 log₁₀ CFU/g with the highest counts being found on green beans. The highest incidence level was of 25.8% for counts within the same range as the aerobic plate counts. Yeast and mould counts showed the highest incidence level between 5 log₁₀ and 6 log₁₀ CFU/g with an overall range between 1.5 log₁₀ and 5.6 log₁₀ CFU/g. L. monocytogenes, Salmonella spp. and S. aureus were detected in 20%, 23.1% and 83.9% of samples, respectively . C. perfringens and B. cereus were not detected in any of the samples analysed.     

Reducing microbial counts on chicken and turkey carcasses using lactic acid

A 4% concentration of lactic acid, buffered to pH = 3.7, was applied by spraying directly after the inside-outside washer of a commercial chicken and a turkey production line with the aim of reducing microbial counts on the carcasses. Slight paling of the skin and slight greying of the leaf fat was observed on the carcasses but this was considered to be commercially acceptable. Microbial reductions varied with length of storage after killing, and after treatment with acid. For both chicken and turkey, there was a highly significant difference (p < 0.001) in aerobic plate counts between control and treated carcasses up to Day 9, but no difference on Days 13 and 16. The largest difference between the aerobic plate counts on control and treated carcasses was 2.1 log₁₀ cfu/g on chicken (Day 6) and 1.1 log₁₀ cfu/g on turkey (Day 9). The prevalence of Campylobacter on turkey carcasses on the day after slaughter was reduced significantly (p < 0.001) by the application of the acid. The results indicate that the application of lactic acid offers a method of reducing microbial counts on poultry and may have implications for shelf life and food safety.     

Efficacy of pulsed electric fields for the inactivation of indicator microorganisms and foodborne pathogens in liquids and raw chicken

This study investigated the ability of pulsed electric fields (PEF) to inactivate a range of microorganisms in liquid media and on raw chicken meat. The susceptibilities of ten Campylobacter isolates (seven Campylobacter jejuni isolates and three Campylobacter coli isolates), Escherichia coli (ATCC 25922) and Salmonella Enteritidis (ATCC 13076) to PEF in liquid media were investigated. All Campylobacter isolates tested in liquid were susceptible to PEF treatment (65 kV/cm, 5 μs, 500 Hz) with reductions of between 4.33 and 7.22 log₁₀ CFU/mL observed for the longest treatment (30 s). Significant differences in susceptibility were observed between Campylobacter isolates subjected to equivalent PEF treatments ranging from 2.41 to 5.19 log₁₀ CFU/mL. Campylobacter isolates processed in liquid media were found to be more sensitive to PEF than E. coli and S. Enteritidis (P < 0.05). The application of PEF (3.75 and 15 kV/cm, 10 μs, 5 Hz) to inoculated samples of raw chicken did not result in any significant reductions in total viable counts, Enterobacteriaceae, C. jejuni, E. coli or S. Enteritidis. Therefore, under the conditions used in this study, PEF technology may not be suitable as a food safety intervention measure for the control of microbial contaminants on broilers during processing although it may have potential to reduce contamination of process water (e.g. scald or spin chill water).     

Quantitative assessment of the effectiveness of intervention steps to reduce the risk of contamination of ready-to-eat baby spinach with Salmonella

The objective of this study was to develop a quantitative risk assessment model to evaluate the microbial hazards during processing of baby spinach leaves using scenario analysis and predictive microbiology. The effectiveness of intervention strategies (temperature control during harvest, washing, and irradiation) was also integrated into the risk assessment model. Monte Carlo simulation was used to take into account the variability of the model parameters.Cross-contamination seems the most probable scenario for prevalence of contamination on an entire lot of daily production. If the cross-contamination level of bacteria was low (∼1 log₁₀ CFU/g, normal distribution) either on the field or after the washing treatments, the percentage of samples over the safety limit (1.33 log₁₀ CFU/g of sample) increased from 16.8% to 84% for a highly cross-contaminated lot (∼3 log₁₀ CFU/g). The risk assessment revealed that exposure of the leafy greens to irradiation (1 kGy) reduces the number of tainted samples from 84% to 0.1%, for highly cross-contaminated lots (3 log₁₀ CFU/g).This study shows that the spinach processor can deliver a highly safe product in a cross-contamination scenario (on the field or packing shed) if the produce is harvested at 20 °C, stored for at least 5 h, washed with water and chlorine (220 ppm), and exposed to irradiation treatment with a dose of 1 kGy.     

Quantification and variability of Escherichia coli and Staphylococcus aureus cross-contamination during serving and consumption of cooked thick porridge in Lungwena rural households, Malawi

The study investigated bacterial transfer to cooked thick porridge via ladles and hands during serving in 29 households in Lungwena, rural Malawi. Household stored water used for hand and ladle washing, was contaminated with Escherichia coli and Staphylococcus. aureus from hands of members of the household or from contaminated ladles used in food preparation. The results showed that hands became contaminated with E. coli and S. aureus cells in the range 0.6–3.7 and 2.2–4.3 log₁₀ CFU/cm², respectively, following washing with the contaminated water. Ladles became contaminated with 0.9–3.2 log₁₀ CFU/cm² of E. coli cells whereas contamination with S. aureus on ladles ranged between 1.9 and 4.6 log₁₀ CFU/cm². Bacterial transfer from hands to food ranged from <1 to 3.6 log₁₀ CFU/g for E. coli and 2.1 to 4.2 log₁₀ CFU/g for S. aureus. Ladle surfaces transferred from 1.3 to 3.1 and from 1.2 to 4.3 log₁₀ CFU/g of E. coli and S. aureus, respectively, on to the food. Contamination of food by hands was significantly (p < 0.05) higher than that of ladles and transfer of S. aureus was significantly (p < 0.05) higher than that of E. coli. The amount of bacteria transferred to the recipient depended on the wash water type and bacteria type. The study has demonstrated that although the traditional cooking of thick porridge inactivates S. aureus and E. coli, the porridge can be contaminated with bacteria during consumption using hands and serving on to a plate with wooden ladles.     

Detection and CRISPR subtyping of Salmonella spp. isolated from whole raw chickens in Yangzhou from China

This study was undertaken to acquire data on Salmonella contamination of whole raw chickens, eggs, and vegetables available to consumers in Yangzhou city, China, between April 2011 and March 2012. In total, 240 chicken carcasses were tested, and the overall contamination rate for Salmonella was 33.8%. While the prevalence of Salmonella in 100 eggs and 155 vegetable samples was 7.0% and 3.2%, respectively. The 84 isolated strains were identified in 19 different serotypes with Salmonella enterica serovar Indiana (S. Indiana) (25.0%), S. Typhimurium (21.4%) and S. Enteritidis (17.9%) as the predominant serovars. Moreover, the median load of the contaminated chicken samples reached 6.4 MPN/100 g with 3.6 MPN/100 g as the 25th percentile and 15.0 MPN/100 g as the 75th percentile. Chicken carcasses collected in October had not only the highest prevalence of Salmonella (70%), but also the highest median load (33 MPN/100 g) and 75th percentile load (460 MPN/100 g), while the lowest prevalence (10%) was in April. The clustered regularly interspaced short palindromic repeats (CRISPR) subtyping method was then used to identify serotypes of Salmonella and distinguish strains from the same Salmonella serotypes. We found that 85.7% of strains were distributed in 11 serotypes speculated by CRISPR typing, which corresponded to the identified serotypes by O and H antiserum. The speculated serotypes of 7.1% of the strains by CRISPR typing are very close to the identified ones, as they belong to the same O group with a small difference in the O or H antigen. All of the above findings implied that CRISPR typing could be applied to serotyping of Salmonella. In addition, CRISPR typing method could be used to subtype different strains from the same serotype, specifically S. Hadar.     

Derivation of performance objectives for Campylobacter in broiler carcasses taking into account impact of selected factors on pathogen prevalence and counts

Food safety standards in the European Union include microbiological criteria and targets in primary production. The current paper provides a strategy to elucidate risk-based metrics such a potential Food Safety Objective for Campylobacter used as benchmark to derive possible Performance Objectives for the pathogen in broiler carcasses tested after chilling. The Performance Objectives were developed using the EFSA data collected on broiler carcasses during the monitoring study performed in 2008 in the European Union according to the evaluation of the different risk factors included in the survey. The FSO for Campylobacter was set at −1.2 log₁₀ cfu/g (∼6 cfu/100 g). The Campylobacter concentrations after chilling resulting in a final concentration equal or below this proposed FSO were suggested as possible POs. The results obtained indicated that batches originating from previously thinned flocks can be more at risk of being colonized with Campylobacter. In fact, the estimated mean concentrations of Campylobacter on carcasses were 1.05 and 2.38 log₁₀ cfu/g for non thinned and thinned flocks, respectively. Further, the impact of high Campylobacter contamination on carcasses (>2.5 log₁₀ cfu/g) was shown since for those carcasses a reduction in PO values higher than 1.5 log₁₀ cfu/g is needed to meet the FSO. In contrast no significant differences for PO values estimated were found between slaughterhouses with different capacity and for carcasses tested at different times from collection. This study provides a validated methodology for the estimation of risk-based metrics based on a quantitative approach allowing food safety authorities to develop specific microbiological criteria.     

Exposure assessment for Bacillus cereus in ready-to-eat Kimbab selling at stores

Kimbab, which is rolled cooked-rice and other foodstuffs in dried laver, is a representative ready-to-eat (RTE) food in Korea. Bacillus cereus is a significant hazard associated with Kimbab. However, the knowledge of the dose–response relationship for B. cereus is limited, now it is not possible to conduct a full microbial risk assessment. Therefore, our study may be focused on the exposure assessment from retail store to the point of consumption in a Kimbab contaminated with B. cereus. The survey data for preparing and selling of Kimbab, predictive growth model, and consumer eating patterns were combined with probabilistic modeling to simulate the level of B. cereus in store Kimbab at the time of consumption. The estimated contamination levels ranged from as minimum (5% percentile) −3.63 log cfu/g, median (50% percentile) 1.39 log cfu/g, mean 1.57 log cfu/g, and a maximum (95% percentile) 7.31 log cfu/g. However, there is always a paucity of data to conduct such full exposure assessments with associated variability and uncertainty, coupled with a validation step. Therefore, we suggest that additional studies to allow for a more realistic and accuracy exposure assessment in the future, based on data gaps we identify.     

Prevalence,antimicrobial resistance profiling and genetic diversity of Campylobacter jejuni and Campylobacter coli isolated from broilers at slaughter in China

A total of 651 samples from broiler cecal samples, carcasses, carcass parts collected at the slaughterhouse level in Sichuan Province of China were examined for the occurrence of Campylobacter jejuni and Campylobacter coli. After confirmed by species-specific multiplex PCR, the recovered isolates were examined for resistance to antimicrobials using an agar dilution method and investigated for the mutation of gyrA, tetO gene and V domain of 23S rRNA as well as the presence of class 1 integron and the associated gene cassettes. In addition, the genotype relatedness of the isolates was determined by pulsed-field gel electrophoresis (PFGE) profiling. The prevalence of Campylobacter was 56.1% in cecal samples, 31.0% in carcasses and 17.0% in carcass parts, respectively. Among them, C. jejuni accounted for 24.6% and C. coli occupied 20.0% of the samples. The strains of C. jejuni were most frequently resistant to ciprofloxacin (88.1%), followed by resistance to tetracycline (79.4%) and levofloxacin (78.1%). Most of the C. coli isolates were resistant to ciprofloxacin (100%), tetracycline (98.5%), levofloxacin (98.5%), clindamycin (98.5%) and erythromycin (93.9%). Antimicrobial resistance profiling showed that 93.7% of campylobacters were multidrug resistant (MDR) strains. Moreover, class 1 integrons were detected in 98.6% of MDR campylobacters, among which 98.7% were positive for C. jejuni and 98.5% for C. coli. Three kinds of gene cassettes-associated amplicons were identified and the amplicons profile of 1000–750–500–250 bp was the predominant pattern linked to the aminoglycoside resistance gene of aadA2. The presence of mutation in gyrA, tetO and 23S rRNA between C. jejuni and C. coli varied from 89.7% to 97.3%, 96.6% to 94.1%, and 95.0% to 96.7%, respectively. Finally, the results of PFGE indicated that, 33 PFGE profiles were generated among 78 isolates of C. jejuni and the similarity level ranged from 42.1% to 99.1%. By contrast, 15 PFGE patterns were produced among 68 C. coli isolates sharing a similarity level of 54.0%–99.7%. Comparison of the PFGE and antimicrobial resistance profiles of the isolates reflected the high genetic diversity of Campylobacter tested. A poor correlation among the antimicrobial resistance patterns, resistance determinants and PFGE genotypes was observed in C. jejuni. Our study showed that there were several points of cross-contamination during broiler slaughter, and a high diversity of PFGE types in the Campylobacter isolates with high resistances to ciprofloxacin and tetracycline.     

Prevalence and fluoroquinolones resistance of Campylobacter and Salmonella isolates from poultry carcasses in Rio de Janeiro,Brazil

To investigate the prevalence of Campylobacter and Salmonella in poultry carcasses in state of Rio de Janeiro, Brazil, 60 samples from 6 slaughterhouses were collected over a period of 6 months. A total of 82 Campylobacter isolates were obtained from twenty seven (45%) positive chicken carcasses, including 44 isolates (53.66%) of Campylobacter jejuni and 38 (46.34%) of Campylobacter coli. The identification of all strains was confirmed by PCR. Salmonella was isolated from 4 (6.67%) carcasses by conventional method and was detected in 5 (8.33%) of 60 chicken carcasses by PCR. Two Salmonella Albany and two Salmonella Typhimurium were identified. Antimicrobial susceptibility testing was primarily done by the disk diffusion method and later by assessing minimum inhibitory concentrations (MICs) against all the isolates. All the Campylobacter isolates were resistant to ciprofloxacin and enrofloxacin. It was observed high MIC values for enrofloxacin (64 μg/mL) in one C. jejuni and two C. coli strains, and for ciprofloxacin (≥128 μg/mL) in one C. jejuni and three C. coli strains. No Salmonella isolate was resistant to these antibiotics by both methods. These findings reveal a broad extent of fluoroquinolone resistance in Campylobacter isolates from chicken carcasses in Brazil and underline the need for prudent use of these antibiotics in poultry production to minimize the spread of fluoroquinolone resistant Campylobacter.     

Systematic review-meta-analysis of the effect of chilling on Campylobacter spp. during primary processing of broilers

Carcass chilling is a critical control point for Campylobacter spp. during the primary processing of broiler chickens. Our objective was to evaluate chilling intervention research that measured the change in Campylobacter prevalence and concentration on broiler chicken carcasses during primary processing using systematic review-meta-analysis (SR-MA) methodology. Experimental and observational research published in English that investigated impacts of chilling on Campylobacter spp. during primary processing of broiler chicken carcasses were considered. Random-effects MA of air chilling resulted in heterogenous summary effect estimates (mean reduction = 0.74 log₁₀ CFU/carcass, 95% CI: 0.32–1.17, I² = 91.3%; and odds ratio = 7.42, 95% CI: 0.32–174.05, I² = 92.3%). Random-effects MA of immersion chilling with chlorine resulted in heterogenous summary effect estimates (mean reduction = 1.74 log₁₀ CFU/carcass, 95% CI: 1.32–2.16, I² = 86.4%; and odds ratio = 0.50, 95% CI: 0.20–1.28, I² = 90.6%). Effects of immersion chilling with unspecified disinfectants were also determined and varied depending on study design. The SR-MA indicated that air chilling and immersion chilling reduce Campylobacter concentrations. Due to conflicting results across studies, the estimated average effect of air chilling on Campylobacter prevalence is not informative. Immersion chilling with chlorine demonstrated a trend towards reduced Campylobacter prevalence, but this result was not significant; results should be interpreted with caution because the overall methodological soundness of included studies was low. Existing research on the effectiveness of broiler carcass chilling on Campylobacter concentration or prevalence is limited and heterogenous. Results generated herein can inform decisions makers and stakeholders on potential effective chilling interventions, and can be used to inform quantitative microbial risk assessment to estimate processing measure impacts on public health.     

Simulation of decontamination and transmission of Escherichia coli O157:H7, Salmonella Enteritidis,and Listeria monocytogenes during handling of raw vegetables in domestic kitchens

Epidemiological data indicates that a large number of foodborne illnesses are attributed to cross-contamination during food preparation in the domestic kitchen. The objectives of this study were to evaluate the efficiency of household washing practices in removing Escherichia coli O157:H7, Listeria monocytogenes, and Salmonella Enteritidis on artificially contaminated lettuce and to determine the transfer rate of these three foodborne pathogens from contaminated lettuce to wash water, tomato, cabbage, and cutting boards during washing and cutting processes. Washing under the running tap water with scrubbing for 60 s was the most effective method in reducing pathogen populations by 1.86–2.60 log₁₀ CFU/g. Also, final rinsing and scrubbing practices were found to enhance the efficiency of washing treatment. In this study, the transfer rates of S. Enteritidis, E. coli O157:H7, and L. monocytogenes from cutting board to cabbage and tomato via cutting process (17.5–31.7%) were higher (P < 0.05) than from wash water to cabbage and tomato (0.8–23.0%) during washing treatment. Overall, our findings suggest that wash water and cutting board can be potential vehicles in the dissemination of foodborne pathogens. Therefore, there is a need to promote consumer awareness for proper handling practices in the kitchen to minimise the risk of foodborne infection.     

High occurrence of Campylobacter spp. in Latvian broiler chicken production

Campylobacteriosis in humans is caused by thermotolerant Campylobacter spp., most commonly by C. jejuni and C. coli. However, no official data for human campylobacteriosis in Latvia is available or cases are heavily under-reported. In accordance with Commission Decision 2007/516/EC the Campylobacter spp. baseline study was performed in 2008 in Latvia but there was no continuous monitoring for the Campylobacter at broiler chicken production level in 2009. The aim of the present study was to determine the occurrence of Campylobacter spp. in broiler chicken production at slaughterhouse and retail level in Latvia. Poultry samples originated from the two biggest Latvian broiler slaughterhouses. Altogether, 240 fresh broiler chicken neck skins, 2400 intact broiler chicken intestines and 240 fresh broiler chicken carcasses were collected during the year 2010. A total of 92.5% of the pooled intestine samples; 60.8% of the neck skin samples and 56.3% of carcasses were positive for Campylobacter spp. There was seasonal variation in proportions of Campylobacter positive samples with seasonal peak on summer months.     

Use of chemical treatments applied alone and in combination to reduce Campylobacter on raw poultry

Research focussing on the use of chemicals to decontaminate poultry carcasses to reduce pathogenic and spoilage organisms has increased in recent years. The objective of this study was to evaluate the efficacy of 12% (w/v) trisodium phosphate (TSP), 2% (w/v) citric acid (CA) and 5% (w/v) capric acid sodium salt (CP) in reducing Campylobacter, total viable counts and total Enterobacteriaceae counts on poultry. These chemicals were also used in various combinations (TSP + CA, TSP + CP and CA + CP) to determine if sequential treatments would enhance microbial reductions. TSP (1.9–2.3 log₁₀ cfu cm²) and CP (2.2–2.4 log₁₀ cfu cm²) gave the largest Campylobacter jejuni reductions while TSP was the most effective at reducing TVC (0.9 log₁₀ cfu cm²) and TEC (0.9 log₁₀ cfu cm²). TSP + CP was the most effective combination treatment (2.9 log₁₀ cfu cm²) for reducing C. jejuni counts and was significantly (P < 0.05) greater than any of the single chemical treatments, with the exception of CP treatment against strain 1146 (2.4 log₁₀ cfu cm²). The TVC and TEC populations proved more resistant to combination treatments as only TSP + CP showed a significantly (p < 0.05) enhanced reductive efficacy in comparison to single CP treatment. This study provides further data on the efficacy of a number of potential chemicals used alone and in combination for the decontamination of raw poultry.