Campylobacter Colonization In Broiler Flocks Research Articles

Survey of the U.S. Broiler Industry Regarding Pre- and Postharvest Interventions Targeted To Mitigate Campylobacter Contamination on Broiler Chicken Products

Campylobacter is one of the most commonly reported foodborne pathogens in the United States. Because poultry is considered a major source of Campylobacter infections in humans, reduction of Campylobacter contamination in poultry products is likely the most important and effective public health strategy for reducing the burden of campylobacteriosis in humans. A comprehensive on-line survey was conducted of key stakeholders in the U.S. broiler industry, including broiler farm managers (n = 18), poultry veterinarians (n = 18), and processing plant managers (n = 20), to assess the current pre- and postharvest Campylobacter interventions and control measures practiced by the industry for reducing Campylobacter contamination of broiler products. The survey also included information regarding each respondent's understanding of Campylobacter transmission and ecology in relation to broiler production. The results revealed that a majority of the establishments included in the survey are following the U.S. Department of Agriculture, Food Safety and Inspection Service guidelines for controlling Campylobacter contamination in broiler flocks and on carcasses. However, establishments appeared to be putting more effort into Salmonella control than into Campylobacter control both on the farm and in the processing plant. A majority of the respondents responded that current interventions are not effective for reducing Campylobacter contamination, especially on the farm. Many respondents did not understand the risk factors associated with Campylobacter colonization in broiler flocks and on carcasses. Continued educational and training programs for key stakeholders in the U.S. broiler industry are needed to increase awareness of the issues associated with Campylobacter infection in broiler chickens and of the fact that Campylobacter infection is a multifaceted problem that requires efforts from both the pre- and postharvest sectors.

Effect of climatic elements on Campylobacter colonization in broiler flocks reared in southern Japan from 2008 to 2012

To demonstrate the effect of climatic elements on Campylobacter colonization in broiler chickens reared in Japan, the correlation between Campylobacter isolated from chickens (191 of 236 flocks, 80.9%) between 2008 and 2012 and climatic elements was analyzed by logistic regression. We divided the rearing process into 13 terms of 5 d each (total: 65 d). Terms were numbered backwards, wherein a 0-term lag was considered as the sampling day plus 4 d before sampling; 1-term lag was the 5-d term before the 0-term lag, and so on, until the 12-term lag. We obtained climatic data tracing back from the 0-term to the 12-term lags. For evaluation in each season, we divided chickens reared during periods of rising temperature (spring, summer) and decreasing temperature (autumn, winter). Air temperature showed a positive correlation with Campylobacter colonization from the 0- to 12-term lags in chickens reared during the period of rising temperature (odds ratio [OR], 1.069 to 1.104), and from the 0- to 4- and 6-term lags (OR, 1.079 to 1.105) in chickens reared during the period of decreasing temperature. The strong positive effect of air temperature on Campylobacter colonization, particularly during the period of rising temperature, may be associated with the effect on the Campylobacter environmental sources and/or vectors. A positive correlation was observed between Campylobacter colonization and humidity when chicken houses were empty and new chicks were introduced (from the 9- to 12-term lags) during the period of decreasing temperature (OR, 1.076 to 1.141). Thus, high humidity would be an important factor causing carry-over of Campylobacter infection during the period of decreasing temperature. We also found that solar radiation increased Campylobacter colonization during the period of decreasing temperature, from the 2- to 8-term lags, except for the 4- and 5-term lags, in Japan. The results of this study demonstrate the effects of air temperature, humidity, and solar radiation on Campylobacter colonization in broiler chickens, and are potentially important for developing strategies to reduce the risk of Campylobacter contamination in broiler chickens.

Climatic factors and prevalence of Campylobacter in commercial broiler flocks in Thailand

Campylobacter are bacteria associated with human foodborne disease worldwide. Poultry and poultry products are generally considered as a main source of these organisms. Compared to temperate zones, baseline information on Campylobacter in tropical regions is limited. Thus, the objectives of the present study were 1) to determine the prevalence of Campylobacter in Thai broiler flocks and 2) to investigate the association between climatic factors (i.e., rainfall, ambient temperature, and relative humidity) and Campylobacter colonization status of broiler flocks in Thailand. A total of 442 commercial broiler flocks reared in the central and northeastern regions of Thailand during 2012 to 2014 were investigated. Campylobacter positive status was identified in 252 examined flocks (57.01%; 95% CI 52.39 to 61.63%). Prevalence of Campylobacter in the northeastern region (54.46%; 95% CI 44.76 to 63.83%) was slightly lower than that of the central region (57.77%; 95% CI 52.47 to 62.90%). More than 65% of Campylobacter positive flocks in the central and northeastern regions had within-flock prevalence higher than 75%. Generalized estimating equations (GEE) revealed that the increased rainfall and relative humidity were associated with the increase of Campylobacter colonization in broiler flocks (P ≤ 0.05), while no relationship between ambient temperature and Campylobacter colonization status was identified.

Prevalence and Antimicrobial Susceptibility ofCampylobacterin Broiler Flocks in Japan

Campylobacter was isolated from 67 (47.2%) of 142 broiler flocks between September 2009 and February 2010. The prevalence of Campylobacter in broiler flocks was significantly lower during January and February than it was from September to December. Campylobacter colonization was more common in flocks that were not provided with a disinfected water supply, which was consistent with the findings of a previous study. The prevalence of antimicrobial drug-resistant Campylobacter spp. was investigated, and the minimum inhibitory concentrations of eight antimicrobial agents were determined for 122 Campylobacter jejuni isolates and 46 Campylobacter coli isolates from broiler flocks between 2007 and 2010. In this study, 29.5% (36/122) of C.jejuni isolates and 41.3% (19/46) of C.coli isolates were resistant to enrofloxacin (ERFX), whereas all isolates were susceptible to erythromycin. Furthermore, the ERFX-resistant isolates were tested for susceptibility to other classes of antimicrobial agents, and 55.6% (20/36) of ERFX-resistant C.jejuni isolates and 47.4% (9/19) of ERFX-resistant C.coli isolates were resistant to at least one of aminobenzyl penicillin, dihydrostreptomycin and oxytetracycline. To avoid an impact of antimicrobial drug-resistant Campylobacter spp. on the efficacy of antimicrobial treatment for human campylobacteriosis, prudent use of antimicrobial agents is a requisite. The use of antimicrobial agents should be accompanied by various approaches such as prevention of Campylobacter colonization in broiler flocks with the aim of lowering the occurrence of Campylobacter infection in humans.

Risk Factors forCampylobacterColonization in Broiler Flocks in Japan

The present study was conducted to estimate the prevalence of and to identify the risk factors for Campylobacter colonization in broiler flocks in Japan. Campylobacter colonization status in flock was evaluated by culturing pooled caecal excrement from 124 broiler flocks. Potential exposure to risk factors was evaluated with a questionnaire for the broiler producers. Odds ratios (ORs) were calculated using a multivariable logistic regression analysis. The prevalence of Campylobacter-positive flocks was 43.5% (upper and lower limits of 95% confidence interval (CI(95%) ): 34.8, 52.3). Multivariable logistic regression model identified two variables as risk factors for Campylobacter colonization. The ORs of Campylobacter colonization were higher in flocks in western Japan (OR=2.68; CI(95%) : 1.04, 6.91) than in eastern Japan, and in flocks supplied with undisinfected drinking water (OR=7.41; CI(95%) : 3.11, 17.66) than in those supplied with disinfected drinking water. These findings indicate that water may play an important role in Campylobacter colonization in broiler flocks in Japan and the use of disinfected water may reduce the risk of Campylobacter colonization.

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.

The sensitivity and specificity of fecal and cecal culture for the detection of Campylobacter in Dutch broiler flocks quantified by Bayesian analysis

Dutch broiler flocks are routinely tested for the presence of thermotolerant Campylobacter spp. using a standard cultural procedure for fecal and cecal samples. The objective of this study was to estimate the sensitivity and specificity of fecal and cecal culture for detection of Campylobacter colonization in broiler flocks in absence of a gold standard. Data from 1600 flocks were used from two different populations, whereby only flocks with both fecal and cecal culture results were included in the analysis. Latent class analysis using Bayesian inference was applied to generate the test characteristics of fecal and cecal culture. Two statistical models assuming conditional dependence of both tests on Campylobacter status were used to compare the results. On flock level, the sensitivity of the fecal culture was found to be 21% (95% CI: 12, 31) and 23% (95% CI: 13, 60), and the specificity was 98% (95% CI: 94, 99) and 97% (95% CI: 92, 99) for the two models, respectively. The sensitivity of the cecal culture was 64% (95% CI: 37, 89) and 66% (95% CI: 39, 90), and the specificity was 98% (95 CI: 94, 99) and 95% (95% CI: 72, 99) in respective models. The implications of a low sensitivity as in the case of the fecal culture is important for the design and interpretation of monitoring programmes and may result in excessive false negative test results. Although cecal culture is the more sensitive test, substantial misclassification of infected flocks may still occur.

Risk factors and likelihood of Campylobacter colonization in broiler flocks

Campylobacter was investigated in cecal droppings, feces, and cloacal swabs of 22 flocks of 3 to 5 week-old broilers. Risk factors and the likelihood of the presence of this agent in these flocks were determined. Management practices, such as cleaning and disinfection, feeding, drinkers, and litter treatments, were assessed. Results were evaluated using Odds Ratio (OR) test, and their significance was tested by Fisher’s test (p<0.05). A Campylobacter prevalence of 81.8% was found in the broiler flocks (18/22), and within positive flocks, it varied between 85 and 100%. Campylobacter incidence among sample types was homogenous, being 81.8% in cecal droppings, 80.9% in feces, and 80.4% in cloacal swabs (230). Flocks fed by automatic feeding systems presented higher incidence of Campylobacter as compared to those fed by tube feeders. Litter was reused in 63.6% of the farm, and, despite the lack of statistical significance, there was higher likelihood of Campylobacter incidence when litter was reused. Foot bath was not used in 45.5% of the flocks, whereas the use of foot bath associated to deficient lime management increased the number of positive flocks, although with no statiscal significance. The evaluated parameters were not significantly associated with Campylobacter colonization in the assessed broiler flocks.

The colonization of broilers with Campylobacter

Poultry is a major reservoir of Campylobacter jejuni, which is currently the leading cause of acute bacterial diarrhoea in western countries. This results in substantial accumulated economic loss due clinical costs and lost working hours. In developed countries reinforcement of hygienic practices and consumer education have so far been inadequate to significantly decrease numbers of human cases of campylobacteriosis. The control of poultry associated infection in humans may also depend upon the control of Campylobacter colonization in broiler flocks. However, sources of C. jejuni and the transmission routes through which broilers become colonized are not clearly defined. A better understanding of C. jejuni epidemiology is urgently needed. This review summarizes current theories on the epidemiology of C. jejuni broiler colonization.