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.     

Campylobacter species and their antimicrobial resistance in Latvian broiler chicken production

In the present study Campylobacter species and their antimicrobial resistance in Latvian broiler chicken production was determined. Furthermore, this is the first report on the antimicrobial resistance patterns for Campylobacter isolates from broiler chickens at slaughterhouse and retail level in Latvia. Two biggest Latvian broiler chicken meat producing company products were included in the study. Altogether, 74 randomly selected broiler chicken Campylobacter spp. isolates were analysed for species identification. Campylobacter isolates were obtained during a 12-month period within the Latvian Campylobacter prevalence study in 2010. Colony multiplex PCR was used for all isolates to identify Campylobacter species. Minimal inhibitory concentration (MIC) was determined for 58 Campylobacter spp. isolates. Resistance to one or more antimicrobials was detected in all 58 isolates (100%). A high proportion of the isolates were resistant to ciprofloxacin (100%) and nalidixic acid (87.9%). Multidrug resistance, which was determined as resistance to three or more unrelated antimicrobials, was detected in 39 isolates (67.2%). Moreover, all multiresistant isolates were resistant to ciprofloxacin and nalidixic acid. Analyses of Campylobacter isolates from two Latvian broiler chicken meat producing companies resulted with significant differences in Campylobacter species; from the company A mainly Campylobacter coli were found, while in the company B Campylobacter jejuni.     

Quantitative microbiological risk assessment (QMRA) of food-borne zoonoses at the European level

At EU level, the European Food Safety Authority (EFSA) is the body responsible for risk assessment in the field of food and feed safety. Following a request from European Union (EU) risk managers, the EFSA Panel on Biological Hazards (BIOHAZ) provided, for the first time, two EU-wide farm-to-fork quantitative microbiological risk assessments (QMRA), with regard to Salmonella in slaughter and breeder pigs and Campylobacter in broilers. The Scientific Opinion on a QMRA of Salmonella in pigs represented a major step forward in terms of modelling from farm to consumption as it took into account the variability between and within EU Member States. This QMRA model was developed to estimate the prevalence of infection/contamination and the microbial load from the farm to the point of consumption (exposure) and then estimating the probability of infection. It was used to investigate the effect of interventions to control Salmonella in pigs at different points of the food chain and resulted in a hierarchy of suggested on farm and slaughterhouse control measures, with estimates of the reduction of human cases. To model the effect of interventions from farm to fork on the incidence of human campylobacteriosis, a QMRA model was developed and used in the framework of the Scientific Opinion on a QMRA of Campylobacter in broiler meat. Reductions to the public health risk of campylobacteriosis could be achieved through a variety of interventions, both in primary production or at the slaughterhouse, with different impacts. Reductions of public health risk using targets at primary production or microbiological criteria were also estimated through modelling using additional models. QMRA of food-borne pathogens at European level has proven a useful/good tool to enable risk managers to evaluate the feasibility and the cost-benefit ratio of introducing control measures and targets to further protect public health of European consumers.     

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.     

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.     

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.     

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.     

Prevalence and counts of Campylobacter spp. in poultry meat at retail level in Estonia

Campylobacter contamination of poultry meat at retail level was studied in two surveys during the twelve-month period of 2012 in Estonia. The data from these surveys were combined and analyzed, partially together, in order to comprehensively estimate the prevalence and possible seasonality of Campylobacter in poultry and in poultry meat products in Estonia. Mostly Estonian, Lithuanian and Latvian products, representing the most typical origins of poultry products on the Estonian retail market, were sampled and analyzed in these surveys. The first survey, organized by the Estonian Veterinary and Food Board, focused on Campylobacter prevalence in poultry meat at retail level. The second survey, at the Estonian University of Life Sciences, focused on Campylobacter prevalence and counts in fresh broiler chicken meat at retail level. Additionally, broiler chicken caecal samples were collected at slaughterhouse level for the estimation of the seasonal variation of Campylobacter colonization. Caecal samples were collected weekly from a broiler chicken slaughterhouse belonging to a company representing over 95% of all commercial broiler production in Estonia. A total of 606 poultry meat samples at retail level and 380 broiler chicken caecal samples at slaughterhouse level were collected and analyzed. A total of 20.8% of the poultry meat and 39.2% of the caecal samples were found positive for Campylobacter spp. The mean number of Campylobacters in fresh broiler chicken meat in the positive samples was 3.20 log₁₀CFU/g. A distinct seasonal variation in the Campylobacter contamination of broiler chicken meat was observed, which peaked during the warm summer period.     

Case-by-case risk assessment of broiler meat batches: An effective control strategy for Campylobacter

In 2006, the Danish government decided to take new measures to control Salmonella and Campylobacter in Danish and imported retail meat. The legal basis for these new measures was article 14 in the EU food law, which states that food shall not be placed on the market if it is unsafe, among others, for reasons of contamination. This provision allows each member state to make a specific risk assessment of food batches, and decide whether a batch poses an unacceptable risk to the consumer or not. Here we present the basis for the risk assessment model on Campylobacter used in this new approach and the results of more than 3000 batches of broiler meat tested since 2007. The risk was assessed for batches with one or more samples positive for Campylobacter (>100 cfu/g). Reductions in the number of positive batches from 2007 to 2010 were observed for both domestic (from 17% to 7%, p = 0.01) and imported broiler meat (from 39% to 18%, p < 0.0001). During 2007–2010, only relatively few batches were deemed unsafe due to the presence of Campylobacter. The proportion of batches of domestic and imported broiler meat deemed unsafe varied from 0.3% to 1.0% for Danish broiler meat and from 0.2% to 7.7% for imported broiler meat. Still this initiative has been successful in significantly reducing the occurrence of Campylobacter in fresh meat available on the Danish retail market.To our knowledge, this is the first example of a risk based control system that enables quantitative day to day risk assessment of food batches.     

Protecting broilers against Campylobacter infection by preventing direct contact between farm staff and broilers

The objective of this study was to test the hypothesis that farm staff are the primary vector of Campylobacter transmission into broiler flocks. On 3 different farms and 5 different flocks (3 flocks on farm 1 and 1 flock on each of farms 2 and 3) a small section of the broiler house (3 × 2 m (farm 1) and 1 m × 1 m (farms 2 and 3)) was sectioned off using Perspex or plastic sheeting. This ‘biosecure cube’ (BC) was populated with 25–125 chicks (test birds), a small subset of the general population of up to 30,000 (control) birds in the broiler house. The BC area incorporated the water and feed-lines thus the test and control birds had access to the same feed, water and air. However, unlike in the general broiler house, the farm staff had no direct access to this sub-population. Dead birds were aseptically removed by the researchers. The birds were tested for Campylobacter (faecal and/or caecal samples), on the day of chick arrival and every 7 days thereafter. In farm 1-flock 1 the general broiler population was Campylobacter-positive after 21 days but the test birds remained negative until day 35. The general broiler population in the other 4 flocks were Campylobacter positive as early as day 14, but in all cases the test birds remained negative. Moreover BC broilers were significantly (P < 0.05) heavier than the control birds (400 g on average), at first thinning. It was therefore concluded that preventing direct contact between the farm staff and the broilers prevents Campylobacter infection in broilers.     

Prevalence,strain identification and antimicrobial resistance of Campylobacter spp. isolated from slaughtered pig carcasses in Brazil

The aim of this study was to investigate the rate of contamination, species identification and antimicrobial resistance of thermophilic Campylobacter spp. in pig carcasses during the slaughter process in a slaughterhouse in Brazil. Two hundred and fifty-nine samples were collected at 7 different stages of the slaughter process for Campylobacter determination by both qualitative and quantitative methods. Typical colonies were subjected to API Campy, real-time polymerase chain reaction (PCR) and antimicrobial resistance testing. Campylobacter was found in 18.9% of the carcasses and 3.5% of the samples. Dehairing was the slaughter stage with the highest Campylobacter contamination (55.6%). All Campylobacter strains were confirmed by real-time PCR and showed multi-drug resistance to cephalothin, nalidixic acid, norfloxacin, tetracycline and trimethoprim. None of the strains were resistant to amoxicillin/clavulanic acid, ampicillin and chloramphenicol. Despite the low occurrence of Campylobacter spp. in pig samples, the antimicrobial resistance of Campylobacter strains represents a considerable risk for the consumption of pork meat and confirms the need for continuous monitoring of Campylobacter in the pig production chain.     

Prevalence,seasonality and antibiotic susceptibility of Campylobacter spp. isolates of retail broiler meat in Iran

Campylobacter species, are the most common cause of bacterial gastroenteritis worldwide. The main route of transmission is generally believed to be via undercooked meat and meat products. This study was conducted to determine the prevalence, seasonality and antibiotic susceptibility of Campylobacter spp. isolates of retail broiler meat in Mashhad, Iran. From January 2013 through December 2013, 360 broiler meat samples were purchased in Mashhad, Iran. Identification of a presumptive Campylobacter species was performed using the cultural method and a polymerase chain reaction (PCR) assay. Antimicrobial susceptibility testing was performed using the disc diffusion method. Overall, 227 samples (63.1%) were positive for Campylobacter. The most prevalent Campylobacter spp. isolated was Campylobacter jejuni (88.1%). There was a significant seasonal prevalence of Campylobacter spp. in broiler meat in Mashhad, Iran (P < 0.0001). The highest isolation rate was also in summer (78.9%). The antimicrobial susceptibility test showed that 93.4% of the isolates were resistant to one or more antimicrobial agents. Resistances to tetracycline (87.2%) and ciprofloxacin (79.3%) were the most common resistances. The findings of this study showed a relatively high prevalence of Campylobacter contamination and antimicrobial resistance in broiler meats in Mashhad, Iran. To the authors' knowledge this is the first study on the seasonal prevalence and antibiotic susceptibility of Campylobacter spp. isolated from broiler meat in Iran.     

Risk-based microbiological criteria for Campylobacter in broiler meat: A comparison of two approaches

Risk-based microbiological criteria can offer a tool to control Campylobacter in the broiler meat production chain. Recently two approaches have been applied to derive such criteria and to analyse their potential impact in terms of human health risk reduction: the risk-based version of the established microbiological criteria approach, that applies a microbiological limit (ML) for sample data, and the Danish “case-by- case” risk assessment approach, that applies a limit for the relative risk estimate (relative risk limit, RRL) based on sample data. In this study, data sets from Sweden and Denmark are used to compare the performance of the two approaches in terms of efficiency, i.e. the balance between the residual risk after implementation of the criterion and the percentage of non-complying batches, and the attending uncertainty. The analysis shows that the two approaches are equally efficient, and suggests that the RRL criterion is attended with less uncertainty. The two approaches are compared and their advantages and disadvantages are discussed. Given the uncertainties attending the results of the analysis, more research in terms of data collection, risk assessment and uncertainty analysis would be needed to develop these risk-based criteria further.     

Quantitative risk assessment of Campylobacter in broiler chickens – Assessing interventions to reduce the level of contamination at the end of the rearing period

The European Food Safety Authority (EFSA) has estimated that a proportion ranging from 20% to 30% of campylobacteriosis in humans may be attributed to the consumption of broiler meat and a reduction in the numbers of Campylobacter in the intestines of infected birds at slaughter by 3 log units would reduce the public health risk by at least 90%. In this study, a stochastic model was implemented to reproduce the dynamics of Campylobacter transmission in broiler flocks and explore the effects of several management conditions and/or on-farm mitigation strategies on the estimated level of contamination of infected flocks at slaughter. Results were expressed as ‘proportion of highly contaminated flocks’ (%HCFs) and estimated as a function of the proportion of infected birds in the flock the day of final depopulation and the individual level of contamination in infected birds. The effects of the mitigation strategies aimed at reducing the level of contamination in infected birds were modelled assuming that those effects are exerted on the distribution describing the bacterial load in infected birds. The impact of management conditions such as the adoption of enhanced biosecurity measures (B+) and/or partial depopulation during the production cycle (T+) were quantified using results of an extensive epidemiological study conducted in UK. A standard broiler flock was reproduced and used as baseline to make comparisons and simulate the effects of the mitigation strategies of interest. The baseline model predicted 18.8% probability of HCFs at slaughter. A positive effect ranging from −32.44% to −4.78% was attributed to B+ while T+ had negative effect ranging from +17.55% to +86.70%. When both the effects were tested simultaneously (B+T+), results were not conclusive with %HCFs ranging from −20.21% to +77.65%. When mitigation strategies operating on Campylobacter concentration in intestine were tested, a reduction of 100% and 99.6% in %HFCs were estimated following a generic treatment with bacteriocins and bacteriophages. Reduction in %HCFs as a function of immunization measures were explored and a reduction of 15% in the rate of transmission led to a %HCFs at slaughter reduced by almost 50%. The model was developed to be flexible, easily reproducible, updatable and adaptable to several baseline scenarios. The main parameters and assumptions underlying the baseline model were tested and a sensitivity analysis was performed to identify and discuss the impact that the uncertainty in the baseline information might have on the outcomes.     

Prevalence of thermotolerant Campylobacter spp. in broilers at retail in the Czech Republic and their antibiotic resistance

Infections caused by thermotolerant Campylobacter spp. are among the most frequent bacterial diseases from food in Europe. An important source of infection is poultry. The aim was to perform the first nationwide study on the prevalence of Campylobacter spp. at retail in the Czech Republic. Samples of chilled and frozen broiler chickens were obtained from supermarkets localized in the eight largest cities in the Czech Republic. From February to November 2009, a total of 120 samples of chilled and 120 samples of frozen poultry were collected and assessed. Qualitative and quantitative analyses were performed according to the ISO 10272-1:2006 and ISO 10272-2:2006 methods. The microdilution method was used to test the resistance of Campylobacter spp. isolates to selected antibiotics. High prevalence of Campylobacter spp. was detected in chilled poultry (75%). The prevalence was significantly lower (37%) in frozen poultry. The most prevalent species was Campylobacter jejuni detected in 70% of positive findings, followed by Campylobacter coli (18%). In 12% of cases, the samples were contaminated by both C. jejuni and C. coli. The species Campylobacter lari and Campylobacter upsaliensis were not detected. The highest resistance rates were to quinolone antibiotics and ampicillin.     

Frequency of contamination and antimicrobial resistance of thermotolerant Campylobacter isolated from some broiler farms and slaughterhouses in the region of Algiers

Campylobacteriosis in humans is caused by thermotolerant Campylobacter spp, following consumption of contaminated poultry, most commonly broiler.The aim of this study was to assess the frequency of contamination by thermotolerant Campylobacter and to characterize antimicrobial resistance of the strains isolated from broilers in some farms and slaughterhouses in the region of Algiers.One hundred droppings samples, 100 contents of ceaca and 100 neck skins were taken from six poultry farms and five slaughterhouses, than analyzed according to NF. ISO 10272-1/1995 norm and the OIE recommendations. Susceptibility to antibiotics was determined according to the guidelines of the CA-SFM/2010 by disc diffusion method.Thermotolerant Campylobacter strains were isolated from 85%, 98%, and 80% of droppings, caecal content and neck skin, respectively. All the strains (100%) were resistant to nalidixic acid and sensitive to gentamicin and to chloramphenicol. 83.7% of them were resistant to tetracycline and to ciprofloxacin, 75.3% to ampicillin, 46.8% to amoxicillin/clavulanic acid and 21.7% were resistant to erythromycin. All the isolates showed a multi-drug resistance. Nineteen different profiles were identified with “AM, AMC, NA, CIP, TE” combination as the most common profile identified for 27% (n = 74) of isolated strains. In addition, 15% of the strains were resistant to both erythromycin and ciprofloxacin, which are systematically used in treatment of human Campylobacter infections.Our results showed a high prevalence of thermotolerant Campylobacter with multidrug resistance profiles in poultry farms and slaughterhouses of Algiers. These results stress that the risk of human contamination throughout the food chain is very high, which may generate: i) a danger of food poisoning by ingestion of chicken meat and chicken meat products and, ii) a cross-resistance to antibiotics between human and avian strains.     

Quantitative analysis of Campylobacter spp. contamination in chicken slaughtering lines by “label tracking method” in eastern China

Campylobacter contamination of poultry meat occurs vastly and inevitably in chicken slaughtering line. The aim of this study was to determine the quantification of Campylobacter spp. contamination levels in chicken slaughtering lines by a “label tracking method”, in eastern China. From the six critical slaughtering steps in 4 slaughtering house, a total of 1260 samples were collected in 236 sampling chicken. Results showed that Campylobacter may propagate in each slaughtering step with a high prevalence (≥83.05%). Both the highest Campylobacter-positive rate and the concentration of isolates were detected at the point of evisceration (97.46%; 2.80 ± 2.52 Log10 CFU/100 cm²), the Campylobacter contamination was mitigated after washing and chilling. However, after flash-freezing, the positive rate of Campylobacter was return to a high value while the concentration was reduced, and frozen storage has been confirmed allowing a mitigation on Campylobacter prevalence, qualitatively and quantitatively. Furthermore, the dynamic variation rule of Campylobacter prevalence obtained from different slaughtering environments was consistent with the rule identified from the corresponding slaughtered poultry. Campylobacter isolates obtained from different slaughtering processes in one slaughter-batch chicken were shown with above 90% homology, pointing to a potential source of contamination. Interventions are needed to minimize Campylobacter contamination, especially in washing, chilling, and frozen storage processes. Our study highlights the quantification of Campylobacter spp. contamination levels in broilers slaughtering line, which would provide quantitative data for the further studies on poultry meat safety control.     

Assessment of the Campylobacter jejuni and C. coli in broiler chicken ceca by conventional culture and loop-mediated isothermal amplification method

In a two-year survey of the 24 Japanese broiler chicken flocks at 9 farms from 2013 to 2014, C. jejuni/C. coli prevalence was assessed in a total of 131 slaughtered broiler chicken cecal samples by conventional culture methods and loop-mediated isothermal amplification (LAMP) assay. While 93 samples were C. jejuni/C. coli-negative, 38 (29.0%) showed Campylobacter loads of between 6.4 and 9.0 log CFU/g of ceca in conventional culture methods. The performance of LAMP assay was 100% accurate in terms of diagnostic sensitivity (38/38), specificity (93/93). Furthermore, LAMP assay enabled direct screening of C. jejuni and C. coli in cecal samples from broiler chicken chickens as rapid and cost-effective detection within 90 min and less than 1 US dollar, which can help monitor release of Campylobacter-contaminated chicken into the food chain, thereby reducing the incidence and public health risk of campylobacteriosis. Seasonal changes in C. jejuni and C. coli prevalence in broiler chicken ceca were significantly correlated with the frequency of food poisoning incidents caused by these bacteria in Japan.     

Biofilm formation of Campylobacter strains isolated from raw chickens and its reduction with DNase I treatment

Campylobacter is a well-known bacterial agent that causes foodborne gastroenteritis. Its biofilm-forming ability is known to be important for its survival in harsh conditions. Poultry is a main reservoir of Campylobacter. In this study, we evaluated the biofilm-forming ability, motility, and antibiotic susceptibility of Campylobacter strains isolated from commercially purchased chickens of various sources in South Korea. From 37 (30%) out of 124 chickens, a total of 78 Campylobacter isolates were obtained, and the ability of these strains to form biofilms was studied on polystyrene surfaces. We identified seven biofilm-forming strains of Campylobacter jejuni and Campylobacter coli, respectively, out of 60 C. jejuni and 18 C. coli strains. Our study demonstrated that motility is inconsistent with biofilm-forming ability, suggesting that motility is not a single factor affecting biofilm formation of Campylobacter. Moreover, there was no clear relationship between antibiotic resistance and biofilm-forming ability. DNase I treatment significantly inhibited the biofilm formation or degraded the mature biofilms of 3 C. coli and 1 C. jejuni biofilm-forming strains (p < 0.05). It suggests that extracellular DNA plays a significant role in the biofilm formation of these strains. Collectively, our study demonstrated that biofilm-forming ability is not strongly correlated with motility and antibiotic resistance in Campylobacter and that extracellular DNA is required for biofilm formation of the isolated Campylobacter strains. It also suggests that DNase I is a potential method for the control of Campylobacter biofilms.     

Effect of extending processing plant operating time on the microbiological quality and safety of broiler carcasses

In Australia, increased consumer demand for chicken meat and socioeconomic pressures have forced poultry operations to extend plant operating time with delayed spin-chiller emptying and cleaning to maximise water use efficiency. There are concerns that these measures may compromise the microbiological quality and safety of the product. Therefore, the objective of this trial was to determine the microbiological status of broiler carcasses collected hourly during 24 h and 48 h continuous chiller operation within a three week period (total n = 196). Carcass rinses were analysed for total viable count, Escherichia coli and Campylobacter spp. counts, and Salmonella prevalence. Corresponding spin-chiller parameters (pH, oxidation-reduction potential [ORP], core temperature and HOCl concentration) were recorded. There was no statistically significant difference (P > 0.05) in bacterial populations and spin-chiller parameters when various sized chickens were processed. Therefore, the microbiological data and consequent quality were shown to be statistically equivalent between carcasses sampled from 24 h to 48 h continuous processing using a fully automated (water temperature, pH and chlorine control) spin-chiller. However, improvements to processing, including rehang and scald hygiene, and weight-specific hypochlorous acid concentrations, should be researched in order to further reduce bacterial contamination.