Campylobacter In Broilers Research Articles

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.

Acidification of drinking water inhibits indirect transmission, but not direct transmission of Campylobacter between broilers

In this study the effect of acidification of the drinking water of broiler chickens on both direct and indirect transmission of Campylobacter was evaluated. In the direct transmission experiment both susceptible and inoculated animals were housed together. In the indirect transmission experiment the susceptible animals were spatially separated from the inoculated animals and no direct animal to animal contact was possible. The transmission parameter β was estimated for the groups supplied with acidified drinking water and for the control groups. The results showed that acidification of the drinking water had no effect on direct transmission (β=3.7day−1 for both control and treatment). Indirect transmission however was influenced by acidification of the drinking water. A significant decrease in transmission was observed (p<0.05), with control vs. treatment point estimates being β=0.075day−1 vs. β=0.011day−1.Apart from providing quantitative estimations of both direct and indirect transmission of Campylobacter in broilers, this study also demonstrates the use of an experimental setup for indirect transmission of Campylobacter between broilers to assess the efficacy of candidate measures to reduce transmission.

Trends in Campylobacter incidence in broilers and humans in six European countries, 1997–2007

The objective of this study was to examine incidences of Campylobacter in broilers and humans, and to describe seasonal variation and long-term trends by comparing longitudinal surveillance data in six Northern European countries (Denmark, Finland, Iceland, Norway, Sweden and the Netherlands). Due to high degree of seasonality and autocorrelation, seasonally adjusted (de-seasonalized) and trend adjusted data (de-trended) were used for comparing incidences within and between the six countries. De-seasonalized time series were obtained by fitting the incidence time series to mean monthly temperature and then removing this effect from the data. Long-term trends were fitted to the de-seasonalized time series. The incidence of Campylobacter colonization in broiler flocks and incidence of campylobacteriosis in humans showed a concordant seasonality for all the countries. There was a strong association between the incidence in both broilers and humans in a given month and the mean temperature of the northern hemisphere in the same month, as well as the preceding month, as shown by the cross-correlations and the chosen Generalized Additive Model. Denmark and Sweden showed a steadily decreasing trend for Campylobacter in broilers and human campylobacteriosis in the period 2001–2007. In Iceland, there was a decreasing trend for campylobacteriosis in humans from 1999 to 2007, whilst the broiler trend for Campylobacter was stable from 2001 to 2004, then falling thereafter. In Norway, the human campylobacteriosis trend showed a steady increase throughout the period. On the other hand, the Norwegian broiler trend for Campylobacter showed a decrease from 2001 until 2004, but was thereafter stable. There was no significant decrease or increase in incidence for human campylobacteriosis in the Netherlands, and the trend for Campylobacter in broilers was close to stable. The seasonality seen in broiler and human closely follows the temperature, and was probably caused, at least partly, by temperature related factors.

Contaminants and microorganisms in Dutch organic food products: a comparison with conventional products

Organic products were analysed for the presence of contaminants, microorganisms and antibiotic resistance and compared with those from conventional products. No differences were observed in the Fusarium toxins deoxynivalenol and zearalenone in organic and conventional wheat, during both a dry period and a very wet period which promoted the production of these toxins. Nitrate levels in head lettuce produced organically in the open field were much lower than those in conventional products. In iceberg lettuce and head lettuce from the greenhouse, no differences were detected. Organically produced carrots contained higher nitrate levels than conventional products. Both organic and conventional products contained no residues of non-polar pesticides above the legal limits, although some were detected in conventional lettuce. Organic products contained no elevated levels of heavy metals. Salmonella was detected in 30% of pig faeces samples obtained from 30 organic farms, similar to the incidence at conventional farms. At farms that switched to organic production more then 6 years ago no Salmonella was detected, with the exception of one stable with young pigs recently purchased from another farm. No Salmonella was detected in faeces at the nine farms with organic broilers, and at one out of ten farms with laying hens. This is comparable with conventional farms where the incidence for Salmonella lies around 10%. Campylobacter was detected in faeces at all organic broiler farms, being much higher than at conventional farms. One of the most remarkable results was the fact that faeces from organic pigs and broilers showed a much lower incidence of antibiotic resistant bacteria, except for Campylobacter in broilers. It is concluded that the organic products investigated scored as equally well as conventional products with regard to food safety and at the same time show some promising features with respect to antibiotic resistance.

Genotypic and Phenotypic Diversity Within Three Campylobacter Populations Isolated from Broiler Ceca and Carcasses

The main aim of this study was to trace Campylobacter subtypes colonizing Italian broilers and carcasses in and between flocks. Overall, 209 Campylobacter isolates were collected from ceca (n = 94) and carcasses (n = 115) of broilers belonging to 3 different flocks reared in the same farm during subsequent rotations and processed in the same slaughterhouse. All isolates were identified by multiplex polymerase chain reaction and genotyped by amplified fragment length polymorphism. Furthermore, 166 out of 209 strains were phenotyped by antimicrobial resistance profile (R-type). The results of genetic and phenotypic characterization showed that (1) multiple Campylobacter species and subtypes can colonize the same broiler and carcass; (2) common Campylobacter subtypes in ceca and carcasses seem to be rare; and (3) carryover of Campylobacter subtypes between broiler flocks in the same house rarely occurs. The outcomes of this study should be taken into account for setting of isolate collection during epidemiological investigations to check sources and transmission routs of Campylobacter in broilers and poultry products.

Characterization of Campylobacter phages including analysis of host range by selected Campylobacter Penner serotypes

BackgroundThe predominant food borne pathogen in the western world today is Campylobacter. Campylobacter specific bacteriophages (phages) have been proposed as an alternative agent for reducing the burden of Campylobacter in broilers. One concern in relation to phage biocontrol is the narrow host range often displayed by phages. To identify the potential of phages as a Campylobacter reducing agent we needed to determine their infectivity on a panel of isolates representing the Campylobacter strains found in broilers as well as humans.ResultsIn this study, Campylobacter phages were isolated from the intestines of broilers and ducks and from abattoir sewage. Twelve phages were investigated to determine their ability to infect the Campylobacter Penner serotypes commonly present in Danish poultry and patients with campylobacteriosis. A total of 89% of the Campylobacter jejuni strains and 14% of the Campylobacter coli strains could be infected by at least one of the bacteriophages. The majority of the phages infected the most common serotypes in Danish broilers (O:1,44; O:2; O:4-complex), but showed limited ability to infect 21 of the less frequent Campylobacter serotypes. Pulse field gel electrophoresis (PFGE) and restriction endonuclease analysis (REA) were used to characterize the phage genomes. Three categories of bacteriophages were observed. I: a genome size of ~194 kb and refractory to digestion with HhaI; II: a genome size of ~140 kb and digestible by HhaI; and III: a genome size undeterminable in PFGE. The categorization of the phages correlated with the host range patterns displayed by the phages. Six phages were subjected to transmission electron microscopy (TEM). They all belonged to the family of Myoviridae.ConclusionWe have characterized and identified the host range of 12 Danish Campylobacter phages. Due to their ability to infect the majority of the common serotypes in Denmark we suggest the phages can become an effective agent in the effort to reduce the incidence of campylobacteriosis in Denmark. This study provides the basis for future experiments in Campylobacter phages and knowledge for the selection of Campylobacter phages for biocontrol in broilers.

Effect of Oral Administration of Bismuth Compounds on Campylobacter Colonization in Broilers

Bismuth compounds have been used since the 18th century to treat gastrointestinal ailments in man. Colloidal bismuth subcitrate (De-Nol) is currently used in combination with antibiotics to reduce enteric Helicobacter pylori colonization as a treatment of stomach ulcers. We investigated whether bismuth citrate or its parent compound, colloidal bismuth subcitrate, would reduce colonization of the closely related foodborne pathogen, Campylobacter jejuni in chickens. In 2 studies, birds were either fed 0, 50, or 200 ppm bismuth citrate or bismuth subcitrate (De-Nol) for 10 or 21 d and were orally challenged with 7 combined strains of C. jejuni (n = 6 birds/treatment). For both treatment groups, cecal Campylobacter colonization was reduced when birds were fed 200 ppm for 10 d but not 21 d. For the 50 ppm treatment group, only birds dosed with bismuth citrate for 21 d demonstrated any reduction in cecal Campylobacter concentrations when compared with controls. These data suggest that bismuth citrate and colloidal bismuth subcitrate may reduce cecal colonization by Campylobacter in broilers, but these effects are inconsistent.

El agente Campylobacter en la producción animal y las estrategias de control para reducir la incidencia de la campilobacteriosis humana

Campylobacteriosis is one of the most important bacterial food-borne illnesses in humans. One significant source of infection is the handling and consumption of poultry meat, although other sources also contribute considerably. Controlling Campylobacter in broilers reduces the human burden of illness. Broilers can easily become colonised with Campylobacter and preventive measures in primary production have a limited and unpredictable effect. Vaccination, competitive exclusion, bacteriophage therapy and the use of bacteriocins are not yet commercially available. However, measures in the slaughterhouse can reduce contamination in the final product. At present, the most promising control strategy is to keep colonised and non-colonised flocks separate during slaughter ('scheduled processing'). The virtually Campylobacter-free meat can supply the fresh poultry meat market, while the meat from infected flocks can be treated to reduce the Campylobacter concentration. Meat from infected flocks can be treated by freezing but chemical decontamination appears to be more cost effective. A variant of this scenario is to treat only highly contaminated meat. The authors conclude that, until new techniques become commercially available, scheduled processing is the most cost-effective approach. Finally, the authors describe trends in antimicrobial resistance in Campylobacter.

Genetic diversity and description of transmission routes for Campylobacter on broiler farms by amplified-fragment length polymorphism

To investigate the genetic diversity of Campylobacter in broilers and in the environment of broiler farms, to compare the genetic profiles and describe critical factors for transmission to broilers. Flocks at three of four investigated farms became colonized with Campylobacter. The total proportion of Campylobacter-positive samples at different farms varied from 20% to 42%. The farm with the poorest biosecurity routines had broilers that became infected earliest, the highest proportion of positive samples and the highest genetic diversity among the broiler Campylobacter isolates. Campylobacter isolates within common amplified-fragment length polymorphism (AFLP) clusters (95-100%) were found to be present in outdoor environment and in broilers at adjacent farms before they were found in the broilers. A large presence of Campylobacter in the farm environment was demonstrated after the broilers were infected. A high genetic diversity was found among Campylobacter present in the outdoor environment, where certain Campylobacter clusters were found for periods of up to 6 weeks. Confirmation by AFLP indicates adjacent poultry farms and outdoor environment as major sources of Campylobacter infection of broilers, this being the novel achievements. The results provide more exact knowledge on transmission of Campylobacter at farm level, helpful for developing optimal preventive strategies.

An evaluation of sampling- and culturing methods in the Norwegian action plan against Campylobacter in broilers

The Norwegian Action Plan against Campylobacter in broilers was implemented in May 2001 with the objective of reducing human exposure to Campylobacter through Norwegian broilers. From each flock, samples collected at the farm about one week prior to slaughter, and then again at the slaughter plant, are examined for the presence of Campylobacter. All farmers with positive flocks are followed up with bio-security advices. Sampling of broiler products at retail level is also included in the Action Plan. The aim of this study was to evaluate the existing sampling and culturing methods of the Norwegian Action Plan against Campylobacter in broilers. The material collected was pooled faecal samples, pooled cloacae samples and caecae samples from individuals. The highest number of positives, from culturing of the pooled faecal samples, the pooled cloacae swabs and the caecae swabs from individuals, were obtained at incubation temperature 41.5 °C. When comparing the results at incubation temperature 37 and 41.5 °C, the faecal samples from the farms demonstrated a high concordance, with a kappa value of 0.88. The results from culturing cloacae swabs and caecae samples from slaughter plant level at two temperatures did not agree very well with a kappa value of 0.21 and moderate value of 0.57, respectively, but were both disconcordant at a level of 0.05. Modelling farm level data indicated that if increasing the number of pooled samples per flock from two (in existing regime) to three, the flock sensitivity increases from 89% to 95%. Modelling of slaughter plant data indicated that three pooled cloacae swabs are needed to identify 90% of the positive flocks. The results from the modelling of caecae data indicated that samples from seven individuals are sufficient to identify 90% of the positive flocks and caecae samples could thus be an alternative to cloacae sampling at slaughter plant level.

Survival of Campylobacter on Frozen Broiler Carcasses as a Function of Time

In the Norwegian Action Plan against Campylobacter in broilers, carcasses from flocks identified as positive before slaughter are either heat treated or frozen for 5 weeks to reduce the number of Campylobacter. The objective of this study was to estimate the effect of freezing time and predict the number of Campylobacter on naturally infected or contaminated broiler carcasses following freezing for 2, 4, 6, 8, 10, 13, 21, 35, and 120 days by nonparametric and parametric linear statistical models. From each of the five flocks, 27 carcasses were sampled. Each carcass was cut in two pieces along the chest bone. Half was put into the freezer (−20°C), whereas the other was deskinned and quantitative culturing was conducted from a 10-g sample of the skin. Fifteen frozen halves were selected at random at each time point following freezing from 2 to 120 days, and skin samples from these were cultured quantitatively and qualitatively. In regard to the log reduction of Campylobacter, almost similar results were obtained using three statistical methods; median regression on the change in Campylobacter counts, zero-inflated negative binomial regression, and a Bayesian Markov chain Monte Carlo (decay) model on original counts. Overall, a 2-log reduction of Campylobacter was obtained after 3 weeks of freezing. Only a marginal extra effect was observed when extending the freezing to 5 weeks. Although freezing appears to be an efficient way to reduce the level of Campylobacter on broiler carcasses, in 80% of the carcasses Campylobacter could still be detected using quantitative culturing following 120 days of freezing. Based on the high number of zeros, these data should be modeled by a zero-inflated model. The best statistical fit in regard to goodness-of-fit measures was the zero-inflated negative binomial log link model, closely followed by the Poisson model. Thus, in our continued search for a better way to describe the data, we used the Poisson distribution in the mixed Bayesian decay models.

Microbiological quality of poultry meat: a review

Poultry meat can be contaminated with a variety of microorganisms, including those capable of spoiling the product during chill storage, and certain foodborne pathogens. Human illness may follow from handling of raw meat, undercooking or mishandling of the cooked product. While Salmonella and Campylobacter spp. remain the organisms of greatest global concern in this respect, others present include the more recently reported Arcobacter and Helicobacter spp. and, occasionally, verotoxigenic Escherichia coli. Also considered here is the growing problem of antimicrobial resistance among poultry-associated pathogens. Because of the need for a systematic and universally applicable approach to food safety control, the Hazard Analysis Critical Control Point (HACCP) concept is increasingly being introduced into the Poultry Industry, and Quantitative Risk Assessment (QRA) is being applied to microbial hazards. Among a number of completed and on-going studies on QRA are those undertaken by FAO/WHO on Salmonella and Campylobacter in broilers. In the case of Campylobacter, however, any QRA must assume at present that all strains have the same pathogenic potential for humans and comparable survival capabilities, even though this is unlikely to be the case. Implementation of the HACCP system in poultry processing plants addresses zoonotic agents that are not detectable by conventional meat inspection procedures and can help to control contamination of carcasses with spoilage organisms. The system brings obvious benefits in optimising plant hygiene, ensuring compliance with legislation and providing evidence of 'due diligence' on the part of the processor. It is now being applied globally in two different situations: in one, such as that occurring in the USA, carcass contamination is clearly reduced as carcasses pass through the process and are finally chilled in super-chlorinated water. There is also the option to use a chemical-rinse treatment for further reduction of microbial contamination. In the second scenario, processors in the EU are not allowed to super-chlorinate process water, and water chilling, which has an important washing effect, is confined to carcasses intended for freezing. Also, chemical decontamination is prohibited until 2006 at the earliest. Therefore, for fresh carcasses that are air chilled, there is presently no marked reduction in carcass contamination and no Critical Control Point at which a significant reduction in pathogen contamination can be guaranteed. Overall, effective control of the organisms is best realised through a farm-to-fork approach at all stages of the supply chain.

Antimicrobial growth promoters and Salmonella spp., Campylobacter spp. in poultry and swine, Denmark.

The use of antimicrobial growth promoters in Danish food animal production was discontinued in 1998. Contrary to concerns that pathogen load would increase; we found a significant decrease in Salmonella in broilers before and after slaughter of swine and pork and no change in the prevalence of Campylobacter in broilers.

Incidence and Levels of Campylobacter in Broilers After Exposure to an Inoculated Seeder Bird

Campylobacter is a very important human foodborne pathogen that is present in commercial broiler flocks. This organism lives in the intestinal tract of broilers without causing avian disease. However, commercial poultry products are frequently implicated as vehicles of human campylobacteriosis. Flocks are typically free of Campylobacter for the first 2 to 4 wk of broiler production. A flock may be completely free of Campylobacter 1 wk but entirely colonized by the next week. This study showed the incidence and level of Campylobacter transmission to pen mates of various ages after exposure to a single colonized seeder bird. Approximately 1 wk after being housed in a pen with an inoculated seeder bird, all of the other birds became Campylobacter positive. This work emphasizes the importance of preventing all sources of Campylobacter from a flock, because a single colonized bird could infect an entire flock during the growout period.

National Surveillance of Campylobacter in Broilers at Slaughter in Denmark in 1998

A surveillance study for thermophilic Campylobacter spp. in broiler flocks was carried out for the year 1998 in Denmark. The study included examinations of 4286 broiler flocks comprising samples from 57,000 birds. Overall, a flock prevalence of 46.0% was recorded. The species distribution was Campylobacter jejuni 86%, Campylobacter coli 11%, Campylobacter lari 1%, other not further diagnosed species 2%. The prevalence was significantly higher in the period from June to October (3.2 < odds ratio [OR] <1.8, P < 0.0002) and was significantly associated with abattoir (OR < 2.8, P < 0.0001) and the length of the period the broiler houses were left empty between flocks (download period; 6 days or more) (OR = 1.6, P < 0.0198). No association between Campylobacter colonization and the age at slaughter was found. Separating the flocks into batches for slaughter elevated the flock prevalence from 0.41 after the first batch had been slaughtered to 0.46 after all batches had been slaughtered.