Abstracts

National Symposium on Campylobacter Intervention

National Symposium on Campylobacter Intervention
December 3, 2017, Chicago Marriott, Downtown Magnificent Mile
           Chicago Ballroom A & B; 5th floor
Funded by USDA National Institute of Food and Agriculture (NIFA), a national symposium on intervention of Campylobacter in poultry will be held on December 3, 2017 in Chicago, in conjunction with the 98th annual Conference of Research Workers in Animal Diseases (http://crwad.org/). The symposium will provide the newest information on innovative strategies to control Campylobacter in the food chain of poultry production.  Feature presentations will be given by national and international experts from academia, industry, and government agencies. The symposium is suitable for researchers, graduate students, extension agents, food safety specialists, public health professionals, and regulatory officials. It is open to public and is tentatively scheduled from 9:00 am to 3:15 pm on Dec. 3, 2017.  Attendance is free. More information on this symposium can be found at www.campypoultry.org. Specific questions about the symposium can be directed to Dr. Orhan Sahin at Iowa State University (osahin@iastate.edu).
Preliminary Program
·   9:00 – 9:10 AM:  Welcome, introduction, and opening remarks. Qijing Zhang, Iowa State University
·   9:10 – 9:30 AM: NIFA’S Food Safety Programs and Impacts.  Max Teplitski, National Program Leader in Food Safety and Microbiology, USDA NIFA.
·   9:30 – 9:55 AM: Epidemiology and risk factors of Campylobacter in commercial broiler production. Orhan Sahin, Iowa State University
·   9:55 – 10:20 AM Industry perspective on Campylobacter control. Bruce Stewart-Brown, Perdue Farms.
·   10:20 – 10:45 AMCampylobacter jejuni glycoconjugate vaccines for poultry. Christine Szymanski, University of Georgia.
·   10:45 – 11:00 AM: Coffee Break
·   11:00 – 11:15 AM: Alternative approaches for Campylobacter control in poultry, Gireesh Rajashekara, The Ohio State University
·   11:15 – 11:30 AM: Novel approaches to reduce risks of Campylobacter infections among consumers, Sanja Ilic, The Ohio State University
·   11:30 – 11:55 AM: Challenges for Campylobacter control in poultry processing. Manpreet Singh, University of Georgia
·   11:55 – 1:30 PM: Lunch break
·   1:30 – 1:55 PM: Post-harvest control of Campylobacter in poultry, Catherine Logue, Iowa State University
·   1:55 – 2:20 PM: European perspective on Campylobacter control , Jaap Wagenaar, University of Utrecht, The Netherlands
·   2:20 – 2:45 PM: Preharvest control of Campylobacter in poultry, Jun Lin, University of Tennessee
·   2:45 – 3:10 PM: Regulatory perspectives on Campylobacter control in poultry, Stephanie Hretz, USDA FSIS.
·   3:10 – 3:15 PM: Closing remarks.  Qijing Zhang, Iowa State University
·   3:30 – 4:30 PM Advisory board meeting and panel discussion (Invitation only)
                      Grace room; 4th floor

Gut microbiota composition influences the outcome of Campylobacter jejuni colonization in chickens

A study was conducted to evaluate the influence of the intestinal microbiota on C. jejuni colonization and local host immune response in chickens under laboratory conditions. Birds were treated with an antibiotic cocktail (broilers) or raised under germ-free (SPF layers) conditions. Following oral inoculation with C. jejuni at 18-days of age, colonization levels in the ceca, liver and spleen, and the local immune responses in the gut were compared between different groups. The results showed the birds with a conventional gut microbiota were significantly less susceptible to Campylobacter colonization in the ceca, spleen and liver compared with the birds with an altered gut microbiota. On the contrary, the local gut immune responses were substantially more prominent in birds with the altered microbiota composition. In addition, C. jejuni induced histopathological intestinal lesions only in the microbiota-altered birds. These results show that the gut microbiota composition significantly affect the colonization (and pathology) of chickens by C. jejuni both locally within the ceca as well as systemically in the spleen and liver. Once identified, key members of the microbiota responsible for this observation could be used as potential prebiotics for control of Campylobacter in poultry.

Different detection methodologies could have significantly different recovery rates for Campylobacter from broiler ceca

Currently, there is no gold standard test for detection of Campylobacter from chicken samples. The performance characteristics of the commonly used diverse panel of detection methodologies (direct culture, enrichment, and PCR) were determined for detection of Campylobacter from cecal contents of slaughter-aged commercial broiler flocks in the United Kingdom. Enrichment in adapted Exeter broth (lacking polymyxin B) with a resuscitation step (pre-incubation at 37˚C for 4 h) followed by subculturing on modified charcoal cefoperazone deoxycholate agar (mCCDA) was found the be the most sensitive (100%) method. Similarly, direct culture on mCCDA yielded very high recovery rate (~98%). On the other hand, enrichment methods using Preston broth and Bolton broth (following subculturing onto mCCDA) were significantly less sensitive. The real-time PCR was able to detect Campylobacter in only 80% of the samples. Interestingly, different enrichment methods promoted the recovery of different Campylobacter species (Exeter broth favoring C. jejuni, while Bolton broth supporting C. coli). These findings indicate that different detection methods could significantly influence the outcomes of studies on Campylobacter incidence in poultry and thus the impact on public health.

USDA approved antimicrobials could significantly reduce Campylobacter counts in ground chicken frames

A study was conducted to determine the efficacy of USDA approved antimicrobials in reducing Campylobacter jejuni in chicken frames (a product similar to mechanically separated chicken). The tested compounds (0.1% peracetic acid [PAA], 0.6% cetylpyridinium chloride [CPC], 0.005% sodium hypochlorite, 1.5% acidified lactic acid [ALA], 0.3% propionic acid, and 0.1% lauric arginate [LAE]) applied as dip treatments. Following spot inoculation of fresh chicken frames with C. jejuni at 3 log CFU/g level, the frames were dipped for 10 s in each of the antimicrobial solution, blended and ground samples were obtained, and stored at 4˚C for 24 h. Results showed that PAA, propionic acid, ALA, and LAE resulted in significant (one log CFU/g) reductions in Campylobacter counts after the4 24 h incubation period. In addition, these antimicrobials did not cause any adverse effect on the meat pH and color. Also noteworthy was that the same treatments were effective against Salmonella, suggesting their broad utility in reducing foodborne pathogens in chicken frames without affecting meat quality.

Some Campylobacter strains could survive for a long period in the poultry processing plant environment

A European study investigated the prevalence and survival of Campylobacter along the slaughter and processing environment (food contact surfaces and non-food contact surfaces) before and after cleaning and disinfection in a poultry slaughterhouse sampling broilers from 7 different farms during a four-week period. Campylobacter (mostly C. jejuni) was isolated from about 50% of the samples, with majority of isolates recovered from the slaughterhouse (surfaces of defeathering, evisceration, sink, and floor areas) as opposed to the processing (surfaces of shackles, conveyer belt, sink and floor areas). Genotyping and whole genome sequencing strongly suggested that some clones of C. jejuni were able to survive he harsh environmental conditions, including cleaning and disinfection, present in the poultry plant (especially in the slaughtering area) for a long period (up to 21 days). These results suggest that Campylobacter could survive in the poultry processing plants longer than it was previously thought and thus could act as a source for contamination of subsequent flocks entering the slaughterhouses.

Probiotics and vaccines work synergistically to reduce Campylobacter colonization in broilers

Previously, a poultry vaccine comprising the N-glycan of Campylobacter jejuni expressed on the surface of an Escherichia coli strain was shown to be highly promising in a subset of chickens following oral challenge with C. jejuni while some birds did not respond. Analysis of the gut microbiota of the responder vs. non-responder birds identified a member of Clostridiales family, Anaerosporobacter mobilis, to be significantly more abundant in the responders. Co-administration of the vaccine and A. mobilis or Lactobacillus reuteri (a well-known probiotic) orally to broiler chickens improved the vaccine efficacy, antibody response and weight gain. An untargeted metabolomic profiling of the cecal contents furthermore identified a potential biomarker (e.g., Clostridial abundance and increased microbial diversity) that was associated with C. jejuni clearance in broiler chickens.

Re-used litter bedding does not appear to increase Campylobacter colonization under commercial settings in poultry.

The effect of three different litter treatment regimens on the level of Campylobacter in ceca and litter on two commercial broiler farms across six production cycles over two years in Australia was investigated. The litter treatments were: 1) the use of new litter after each farming cycle, b) an Australian partial litter re-use practice, and 3) a full litter re-use practice. Campylobacter levels changed only minimally across the litter practices, and were in the range of log 8-9 CFU/g ceca and log 4-6 MPN/g litter. The patterns of Campylobacter emergence/presence across time varied between the farms, cycles and the point of testing (e.g., at thinning and final pick-up). The emergence and levels of Campylobacter was found not to be influenced by litter treatment on either of two farms across the six production cycles. It was shown that either C. jejuni or C. coli could be the dominant species regardless of the specific litter practice. It was also observed that cycle 2 on one of the farms was always Campylobacter free irrespective of the litter treatments in place. Of note, similar results were obtained for generic Escherichia coli. These findings suggest that different litter treatment practices in place on commercial poultry farms have an insignificant effect on the onset and level of Campylobacter in ceca and litter.

A low pH processing aid to reduce Campylobacter counts on broiler carcasses.

Effectiveness of a low pH processing aid (CMS PoultrypHresh) against Campylobacter on skin-on split chicken breast or skin-on chicken thigh was determined after artificial inoculation of the meats with C. coli. Treatment of the chicken parts with PoultrypHresh for 25 s with agitation (bubbled air) resulted in 99.6% reduction in Campylobacter counts on split breast and 99.4% reduction on thighs as compared with deionized water. This study indicates that an approximate 3 log reduction achieved by a 25 s air agitation treatment in PoultrypHresh at pH 1.4 with no observable damage to meat will help processors to meet new regulations and performance standards set by USDA Food Safety and Inspection Service.

Risk factors for carcass contamination by Campylobacter at the slaughter in Belgium.

In order to identify the risk factors for contamination levels on broiler carcasses by Campylobacter, the levels of the organism on carcasses were quantified across the slaughter line during the processing of Campylobacter positive flocks. The microbiological results were combined with the slaughterhouse and batch related characteristics for analysis. It was found that the higher contamination level of incoming birds on feathers and in ceca, and the shorter transport and holding time of live birds (associated with shorter feed withdrawal time) increased the level of Campylobacter counts on carcasses at the 5 different sampling sites throughout the slaughter process. In addition, several technical characteristics of the slaughter process such as a dump based unloading system, electrical stunning, lower scalding temperature, incorrect setting of plucking, vent cutter and evisceration equipment were associated with higher counts of Campylobacter on processed carcasses.  This study suggests that poultry slaughterhouse operations can implement several changes during the processing steps that are both practical and economical without use of chemical or physical decontamination.

Farm specific risk factors for Campylobacter colonization in Danish and Norwegian broilers.

A bi-national risk factor survey comprising large amount of Campylobacter data from over 5200 conventional broiler flocks on 277 farms in Denmark and Norway was undertaken using multiple epidemiological models. Analysis indicated that Norwegian flocks had a lower risk than Danish flocks for Campylobacter carriage. In both countries, broiler houses older than 5 years, longer downtime between consecutive flocks, houses without a separate ante-room/barrier and the use of drinker nipples with cups/bells were associated with increased risk of Campylobacter colonization in broiler flocks. For Norway only, having larger numbers of houses on a farm, and the use of surface water or bore holes instead of mains increased the risk of Campylobacter colonization. For Denmark only, having boot dips or low stocking density was associated with increased risk of flocks being Campylobacter positive. Having a better understanding of the risk factors involved in flock colonization by Campylobacter is of paramount importance to develop and implement effective farm-based interventions.

Highly promising Campylobacter poultry vaccines appear to be on the horizon.

Glycoconjugate vaccines combining the conserved N-glycan (i.e., carbohydrate or sugar) of Campylobacter jejuni with a protein carrier (GlycoTag), or fusing the same N-glycan molecule to the outer core region of Escherichia coli lipopolysaccharide were constructed and evaluated for their ability to prevent colonization by C. jejuni in layer chickens. Vaccination of birds either with the glycoprotein (GlycoTag)-based vaccine (given intramuscularly in the chest or leg), or with inactivated/live E. coli cells displaying the C. jejuni N-glycan on their surface resulted in up to10-log reduction in C. jejuni colonization in the ceca and induced N-glycan-specific systemic antibody response. Moreover, the live E. coli vaccine was shown to be self-limiting (i.e., cleared from the chickens in a short period) and it did not alter the composition or the complexity of the microbial community in the chicken intestine. Altogether, these results indicate that an efficacious poultry vaccine to reduce Campylobacter at the source in the primary animal production may be not too far away.

Highlights from 18th International Campylobacter Conference

CHRO 18th International Workshop on Campylobacter, Helicobacter & Related Organisms (CHRO) was held on November 1-5, 2015 in New Zealand (http://www.chro2015.com/).  The conference hosted a few hundred attendees from academia, government and industry from all over the world. The presenters communicated their very recent research findings on a wide range of topics including epidemiology, genomics and diagnostics. A significant portion of the talks (including the plenary lectures as well as keynotes) were dedicated to Campylobacter in poultry including the source of infection, colonization characteristics, and control strategies at both preharvest and postharvest levels.
 
The presenters from Europe under CamCon project provided two brochures on Campylobacter at poultry farm level with the intent of communicating research findings with poultry producers to facilitate education and implementation of practical measures for reducing the risk of Campylobacter on farms. Both brochures (Best Practice Manual; Draft Certification Program) as well as an “e-learning program on Campylobacter” are available online at www.camcon-eu.net .  It should be noted that information provided in these resources is for general guidance only and would need to be integrated into existing systems and quality programs in the US poultry production conditions to be applicable and effective.

Intra-cloacal inoculation as an effective screening method of potential probiotics against Campylobacter in poultry

Bacterial isolates collected from healthy chickens and shown to have anti-Campylobacter properties in vitro were evaluated for efficacy against C. jejuni after oral or intra-cloacal inoculation into day-old broiler chicks. Seven days after, the birds were challenged orally with C. jejuni and numbers of Campylobacter in ceca were determined at necropsy on day 14 of age. Only one bacterial isolate had a 1-log reduction in Campylobacter counts following oral dosage, while six of the isolates from healthy birds produced a 1-3 log reduction in cecal Campylobacter counts when given intra-cloacally. The results indicate that screening of potential probiotic isolates by directly placing them in the lower intestinal tract via cloacal inoculation may eliminate the time and expense of encapsulating ineffective isolates.

Efficacy of commercial antimicrobials on Campylobacter varies between types of poultry meat.

Under simulated commercial water chilling conditions, the effectiveness of trisodium phosphate (TSP) and sodium hypochlorite (SH) against Campylobacter on skinned duck meat and chicken meat was determined after artificial inoculation of the meats with a cocktail of Campylobacter at two different inoculum level. All three TSP concentrations significantly reduced numbers of Campylobacter on both duck and chicken meat. Whereas higher concentrations of TSP resulted in a Campylobacter contamination level less than the limit of detection on duck meat regardless of the dose of inoculum, the same effect was observed in chicken meat only when challenged with the low dose of inoculum. The effectiveness of SH was less prominent than that of TSP on both type of meats. The results indicate that chicken meat could effectively protect Campylobacter against TSP and SH while duck meat could not. Of note, similar results were obtained with Salmonella, indicating the potential of TSP for application in a commercial poultry processing to reduce foodborne pathogens, especially on duck meat.

Comparison of Campylobacter contamination of broiler carcasses in two slaughterhouses.

In order to provide clues into the causes of differences in Campylobacter contamination on broiler carcasses after chilling between slaughterhouses, Campylobacter counts on carcasses were determined at various processing steps (e.g., after bleeding, scalding, defeathering, evisceration and chilling) in two slaughterhouses involving 21 batches. Both slaughterhouses had comparable levels of Campylobacter concentrations in the incoming batches (after bleeding); however, the mean level of counts on carcasses after chilling was significantly different. Effect of processing steps on Campylobacter counts among batches varied between the slaughterhouses. The pattern of increases and decreases in Campylobacter concentrations during processing were specific for each slaughterhouse, potentially explaining the differences in contamination levels after chilling between slaughterhouses. Also, changes in E. coli concentration levels during processing were similar to Campylobacter (except defeathering), suggesting that E. coli has a potential to be used as an indicator for processing hygiene. 

Campylobacter carcass contamination at processing plants slaughtering highly-colonized broiler flocks.

Descriptive analysis of Campylobacter counts in four slaughterhouses, comprising twelve different Campylobacter-positive batches (highly colonized in their ceca, >7.9 log10 cfu/g) and seven different sampling sites within each batch, is performed. High counts of Campylobacter on feathers were positively associated with the breast skin contamination of incoming birds and carcases after plucking. Campylobacter contamination of breast skin samples varied considerably within batches and between batches in the same slaughterhouse and between slaughterhouses. Percentage of Campylobacter-positive carcasses after chilling at different slaughterhouses ranged from 11% to 78%, indicating that certain plants are able to better control Campylobacter contamination than others.

Contamination of broiler carcasses by Campylobacter at the slaughterhouse level.
Dynamics of presence, and genotypes of Campylobacter jejuni on the neck skin samples from the same broiler carcasses at three successive slaughter line locations in the evisceration room, after three day refrigeration and after three day freezing, as well as in cecal samples from the same birds and in slaughterhouse environment was determined in six slaughter batches. On average, the highest C. jejuni skin contamination was detected at the first sampling point (post-plucking), indicating where the majority of contamination might occur. Additional increases in contamination level of carcases were evident after the evisceration step in some batches. Refrigeration and especially freezing caused significant drops in the C. jejuni contamination levels. Typically, one genotype was present on the carcasses per batch. Although slaughterhouse environment (except scalding tank water) could be cross-contaminated by genotypes from different batches, carcasses from each batch were typically contaminated by the strains present in the corresponding cecal samples.
Highly specific antibodies to reduce Campylobacter colonization in chickens.

Llama single-domain antibodies specific for C. jejuni were isolated from a phage display library generated from the heavy chain IgG variable domain repertoire of a llama immunized with C. jejuni flagella. Two flagella-specific single-domain antibodies were combined to generate high avidity antibodies capable of multivalent binding to target antigen. Oral administration of specific antibodies to C. jejuni-infected young broilers resulted in significant reduction in the C. jejuni colonization in the ceca. The antibodies also reduced the motility of the bacterium in vitro.

Immunization to reduce Campylobacter colonization in broiler chickens.

Laying hens were immunized with either a whole-cell lysate or the hydrophobic proteins of C. jejuni and their eggs were collected. Specific antibodies were shown to be induced in the egg yolk. Preventive administration of hyperimmune egg yolk significantly reduced Campylobacter colonization of seeder birds after inoculation with C. jejuni as well as transmission of the bacterium to non-seeder birds was even completely eliminated. Purified antibodies promoted bacterial binding to the chicken intestinal mucus, suggesting enhanced mucosal clearance in vivo. Further analyses identified several immunodominant proteins that could have potential for subunit vaccine development.

Risk factors for Campylobacter colonization of commercial broilers in France.

Campylobacter was isolated from 72% (87/121) of broiler flocks with average the concentration in positive flocks was about 8 log10 cfu/g feces at the end of the rearing period. Campylobacter prevalence was increased in June, July and August compared with other periods of the season. The other factors associated with lower risk of Campylobacter colonization were the acidification of drinking water, antibiotic treatment at the beginning of the rearing period, and rodent control around the house. These results indicate that hygiene practices and biosecurity measures could lead to a reduction in Campylobacter colonization in broilers.

Organic acids as water additives for preharvest intervention of Campylobacter in broilers.

A commercial organic acid (Selko, 4Health, the Netherlands; which contains a blend of short-chain organic acids and medium-chain fatty acids) was added to drinking water during the entire grow-out period of commercial broiler chicken flocks. Acidified drinking water did not have negative impact on production parameters or animal welfare. Although Campylobacter carriage by the flock and in cecum content was reduced by organic acid treatment, it did not have any substantial effect on the carriage of Campylobacter on the corresponding carcasses of the slaughtered birds. The addition of organic acid to drinking water of broilers can potentially lower the cecal carriage of Campylobacter in primary production, but it failed to have an impact on the bacterial load after slaughter.

Impact of disinfectant wipes for Campylobacter intervention during food preparation.

A quantitative microbial risk assessment study was conducted to determine the exposure to Campylobacter jejuni contaminated surfaces during raw chicken preparation and how the use of a disinfectant wipe to clean the contaminated area would reduce the risk of contamination in domestic kitchens. It was found that disinfectant wipe intervention reduced the risk of C. jejuni contamination of kitchen surfaces and areas by 2 to 3 orders.

Campylobacter in Domestic ‘Backyard’ Poultry

Poultry fecal samples were collected from 35 domestic ‘backyard’ poultry flocks from urban and rural properties. There was a high prevalence of Campylobacter spp. with 86% of flocks testing positive.  Campylobacter database showed that 28 of the genotypes had previously been isolated from human cases of campylobacteriosis.  

Tracing Campylobacter from farm to retail

Campylobacter jejuniwere recovered from birds, carcasses and carcass portions from two broiler chicken flocks and from equipment used for carcass and meat processing along the production chain from farms to retail stores. C. jejuni was recovered from product and equipment used with both flocks at each point in the production chain. The prevalence of C. jejuni in poultry products at retail stores was 58.97% (flock 1) and 69.23% (flock 2).  Most PFGE types were resistant to ciprofloxacin (95.45%) and tetracycline (81.82%); and multidrug resistant PFGE types were found in the final products. 

Consumer acceptability of Campylobacter interventions

A survey of consumers in Scotland found that better hygiene practices on farm, freezing chicken meat and vaccination of chickens were acceptable to the majority of participants whilst irradiation and chemical wash of chicken meat were acceptable to <50%.  Chemical wash and irradiation remained the least acceptable interventions.  Previous awareness of Campylobacter did not influence consumer concern of harmful bacteria on chicken meat. Overall, findings indicate that increasing consumer acceptability of the most effective interventions is likely to be a difficult process.

Steam and ultrasound reduce Campylobacter on broiler carcasses

A combination of steam with ultrasound (SonoSteam®) was investigated on naturally contaminated broilers that were processed at conventional slaughter speeds of 8,500 birds per hour.  Industrial-scale SonoSteam equipment was installed in the evisceration room, before the inside/outside carcass washer. Results obtained from this study suggest that steam-ultrasound treatment of carcasses at broiler processing plants can significantly reduce numbers of Campylobacter on naturally contaminated broilers.  An authorized sensory panel concluded that broiler carcasses treated with SonoSteam were acceptable for purchase. These conclusions were based on organoleptic differences (smell, skin/meat consistency, texture and color) of treated vs. untreated carcasses.

Passive immunization to reduce Campylobacter in broiler chickens

Laying hens were immunized with either a whole-cell lysate or the hydrophobic protein fraction of C. jejuni and their eggs were collected.  In vitro tests validated the induction of specific immunoglobulinY (IgY) against C. jejuni in the immunized hens' egg yolks. Preventive administration of hyperimmune egg yolk significantly reduced bacterial counts of seeder animals three days after oral inoculation with approximately 104 cfu C. jejuni.  Transmission to non-seeder birds was dramatically reduced (hydrophobic protein fraction) or even completely prevented (whole-cell lysate).  Purified IgY promoted bacterial binding to chicken intestinal mucus, suggesting enhanced mucosal clearance in vivo

Carry-over of Campylobacter between poultry flocks

Poultryflocks were largely colonized by more than one AFLP type and an intense exchange of Campylobacter genotypes between different poultry flocks occurred. These findings indicate that multiple genotypes can constitute the Campylobacter population within single poultry flocks. Nevertheless, in most flocks single Campylobacter genotypes predominated. Some strains superseded others resulting in colonization by successive Campylobacter genotypes during the observation period. 

Campylobacter Cross‐Contamination of Chicken Products at an Abattoir

51.1% of chicken products originating from Campylobacter-positive flocks were contaminated with bacteria.  In contrast, only 18 (7,2%) of 250 chicken products derived from Campylobacter-negative flocks were contaminated.  In 14 of these 18 products, the Campylobacter isolates were identical to isolates obtained from flocks slaughtered immediately prior to the Campylobacter-negative flock.  On 4 of 6 slaughter days, Campylobacter-negative flocks were slaughtered prior to positive flocks, and Campylobacter was absent from all chicken products originating from these negative flocks.  Implementation of logistic slaughter (where Campylobacter-negative flocks are slaughtered first) significantly decreases the prevalence of Campylobacter-positive chicken flocks.

Campylobacter reduction and quality of poultry carcasses treated with antimicrobials in a post-chill immersion tank

Broiler carcasses were analyzed to evaluate the efficacy of five post-chill water treatments consisting of 40 ppm total chlorine, 400 ppm or 1000 ppm peracetic acid (PAA), and 1000 ppm or 5000 ppm lysozyme against Salmonella and Campylobacter spp. Treatment with 400 ppm or 1000 ppm PAA was most effective in reducing populations of Salmonella and Campylobacter as compared to the chlorine treatment at 40 ppm and lysozyme treatments at 1000 ppm or 5000 ppm. Treatment with the various antimicrobials was not found to have negative impacts on sensory attributes.  PAA as an antimicrobial in a post-chill immersion tank is an effective application for reducing Salmonella and Campylobacter on carcasses while maintaining product quality.

Effects of chemicals on Campylobacter and sensory characteristics of poultry meat

In the broiler processing plant, immersion in trisodium phosphate (TSP 14%) or citric acid (CA 5%) achieved Campylobacter reductions of 2.49 and 1.44log₁₀cfu/cm, respectively. There were no significant differences between the treatments for any of the sensory attributes measured in either raw or cooked drumsticks. The ‘color’ of raw chicken fillets treated with both TSP and CA was significantly lighter than that of control samples. The ‘intensity of chicken odour’ and the perception of ‘salt’ in cooked chicken fillets treated with CA were also significantly higher than that of either control or TSP treated samples. It was concluded that TSP or CA could be applied to significantly reduce Campylobacter contamination of broilers without adversely affecting the sensory quality of the product.

Probiotics reduce colonization of Campylobacter in broilers

One-day-old broiler chicks received 2 mg/bird per day of a multispecies probiotic product via the drinking water.  Controls received no probiotic treatment, and all chicks were infected with C. jejuni orally. Results of two experiments both showed that the cecal colonization by C. jejuni was significantly reduced by probiotic treatment at both 8 and 15 d postchallenge. 

Campylobacter in High-Shedding Flocks

Broilers excreting Campylobacter spp. at high levels (>7 log CFU/g of feces) are an important source of carcass contamination. Risk of infection to humans could be economically and efficiently minimized by eliminating these flocks from fresh poultry meat chains.  A simple and rapid gold-labeled immunosorbent assay (GLISA) for the identification of Campylobacter spp was evaluated.  Results were obtained within 2 hours.  Test sensitivity was 89.5% and specificity was 94.5%. Given a GLISA detection limit of 7.3 log CFU/g of feces, nearly all Campylobacter-positive flocks were identified as "high shedders." Therefore, reduction of the incidence of Campylobacter infections by elimination of high-shedding flocks is an unrealistic approach. 

Campylobacter and Pododermatitis

Flocks of fast- and slow-growing breeds of broiler chickens were reared to a standard commercial slaughter weight. At 21 days, birds were either infected with Campylobacter jejuni or given a placebo as control.  Fast- and slow-growing birds did not show detectably different levels of Campylobacter carriage.  Infection with C. jejuni increased the incidence of hock marks and pododermatitis in both breeds.  The incidence of pododermatitis was significantly higher in Campylobacter-positive fast-growing birds than in their slower-growing counterparts. 

Campylobacter in the Environmental and on Processed Carcasses

Air samples, fecal/litter samples, and feed/drink line samples were collected from 4 commercial chicken grow-out houses.  Birds from each sampled house were also sampled by postchill carcass rinses. Campylobacter was detected in 27%  of house environmental samples and 37.5%  of carcass rinse samples. The sponge sample method was found to have a significantly higher proportion of Campylobacter-positive samples (45%) than the fecal/litter samples (20%) and air samples (15%). For each flock, positive fecal/litter samples for each flock had the highest correlation (0.85) to positive carcass rinse samples. 

Prevalence and risk factors of Campylobacter in broilers from Spain

The prevalence of Campylobacter in individual broilers was 38.1%, and the flock prevalence was 62.9%. Flocks were predominantly infected by C. jejuni and C. coli but were also infected by untyped Campylobacter spp., and mixed-species infection could be found.  Analysis indicated five factors associated with increased intra-flock prevalence: 1) presence of dogs or cats on the farm, 2) older age of the broiler flock, 3) thinning of flocks, 4) presence of windows with canvas blinds, and 5) presence of rodents in the poultry house. Two factors were associated with decreased intra-flock prevalence: 1) treatment of drinking water and 2) entrance rooms for access into poultry houses. 

Low-cost monitoring of Campylobacter in poultry houses

Sampling was conducted over an 8-week period in three flocks, assessing the presence and levels of Campylobacter in boot swabs and air samples using quantitative real-time PCR. Using air sampling, Campylobacter was detected in the flocks right away, while boot swab samples were positive after 2 weeks. All samples collected were positive for Campylobacter from week 2 through the rest of the rearing period for both sampling techniques, although levels 1- to 2-log CCE higher were found with air sampling. At week 8, the levels were approximately 10(4) and 10(5) CCE per sample for boot swabs and air, respectively. In conclusion, using air samples combined with quantitative real-time PCR, Campylobacter contamination could be detected earlier than by boot swabs and was found to be a more convenient technique for monitoring and/or to obtain enumeration data useful for quantitative risk assessment of Campylobacter.

Water acidification and Campylobacter reduction

In vitrotests indicated that a commercially available acidified water treatment (PWT) was highly effective for reducing Campylobacter jejuni and Campylobacter coli at the recommended concentration in water, reducing populations by greater than 7 log10 CFU/ml after 24 h exposure.  Addition of PWT to the broiler drinking water for the first 7 d, 2 d before and 2 d after each feed change and at feed withdrawal prior to slaughter or only after feed withdrawal had no effect on the number of Campylobacter in cecal samples on farm before thinning and depopulation compared to untreated controls.  Although PWT was effective for reducing Campylobacter in water, it does not reduce the number of Campylobacter in the ceca of broilers prior to slaughter under the conditions used in the study. 

Poultry as a Host for Campylobacter jejuni

Chickens are a natural host for Campylobacter jejuni and that colonized broiler chicks are the primary vector for transmitting this pathogen to humans.  Initially, one or a few broilers can become colonized at an age of >2 weeks until the end of rearing, after which the infection will rapidly spread throughout the entire flock. Such a flock is generally colonized until slaughter and infected birds carry a very high C. jejuni load in their gastrointestinal tract, especially the ceca. This eventually results in contaminated carcasses during processing, which can transmit this pathogen to humans.  Chicken isolates can frequently be linked to human clinical cases of Campylobacter enteritis. 

Single Phage and Phage Cocktails to Reduce Campylobacter jejuni in Broilers

Commercial broilers were inoculated with a Campylobacter jejuni field strain and subsequently treated with a single phage or a four-phage cocktail.  Afterwards, birds were examined for their loads with phages and Campylobacter on day 1, 3, 7, 14, 21, 28, 35 and 42 after phage application.  The deployed phages persisted over the whole investigation period. The Campylobacter load was permanently reduced by the phage-cocktail as well as by the single phage. The reduction was significant between one and four weeks after treatment.  Phage resistance rates of initially up to 43% in the single phage treated group and 24% in the cocktail treated group later stabilized at low levels. The occurrence of phage resistance influenced but did not override the Campylobacter reducing effect.

Campylobacter jejuni Infections Associated with Undercooked Chicken Livers

In October 2012 the Vermont Department of Health (VDH) identified three cases of laboratory-confirmed Campylobacter jejuni infection in Vermont residents.  A query of PulseNet, the national molecular subtyping network for foodborne disease surveillance, led to the identification of one additional case each from New Hampshire, New York, and Vermont that had been reported in the preceding 6 months.  All six patients had been exposed to raw or lightly cooked chicken livers that had been produced at the same Vermont poultry establishment. Livers collected from this establishment yielded the outbreak strain of C. jejuni.  Public health professionals, members of the food industry, and consumers should be aware that chicken livers often are contaminated with Campylobacter and that fully cooking products made with chicken liver is the only way to prepare them so they are safe to eat.

Effects of chemical treatments on Campylobacter and poultry meat

In a broiler processing plant the efficacy of using TSP (14%) and CA (5%) applied by immersion and spray was investigated using naturally contaminated carcasses and the effect of these treatments on the sensory attributes of a skin-on (drumstick) and skin-off (fillet) raw and cooked product was assessed. Immersion in TSP (14%) or CA (5%) achieved Campylobacter reductions of 2.49 and 1.44log10 cfu/cm(2), respectively. There were no significant differences between the treatments for any of the attributes measured in either raw or cooked drumsticks. The 'colour' of raw chicken fillets treated with both TSP (14%, w/v) and CA (5%, w/v) was significantly (P≤0.05) lighter than that of control samples. The 'intensity of chicken odour' and the perception of 'salt' in cooked chicken fillets treated with CA (5%, w/v) were also significantly (P≤0.05) higher than that of either control or TSP (14%, w/v) treated samples. It was concluded that TSP (14%) or CA (5%) could be applied to significantly reduce Campylobacter.

Campylobacter reduction on poultry carcasses with antimicrobials

A total of 160 broiler carcasses were analyzed to evaluate the efficacy of five post-chill water treatments consisting of 0.004% (40ppm) total chlorine, 0.04% (400ppm) or 0.1% (1000ppm) peracetic acid (PAA), and 0.1% (1000ppm) or 0.5% (5000ppm) lysozyme against Salmonella and Campylobacter spp.  In addition, sensory analysis was performed to evaluate any associated effects of the antimicrobials on quality attributes of chicken breast meat.  Treatment with 0.04% and 0.1% PAA was most effective (P≤0.05) in reducing populations of Salmonella and Campylobacter as compared to the chlorine treatment at 0.004% and lysozyme treatments at 0.1% and 0.5%, as well as the water treatment and the positive control.  Treatment with the various antimicrobials was not found to have negative (P≤0.05) impacts on sensory attributes.

Freezing reduces campylobacters from chicken livers

Chicken livers naturally contaminated with campylobacters were subjected to freezing at -15 and -25°C for one day and 7 days.  Numbers of campylobacters on the livers were determined immediately before and after a 24-h or 7-days freeze treatment and daily during 3 days post-thaw refrigerated storage.  Freezing for 24 h at -25°C can reduce numbers of Campylobacter by up to 2 log10 CFU g(-1).  Freezing the livers for 24 h at -25°C, thawing overnight in a fridge set to 4°C and refreezing for another 24 h at -25°C reduced the numbers of campylobacters by up to three logs.  Reduction in the numbers of campylobacters was significantly greater following a second freeze treatment compared with a single freeze treatment.  Freezing chicken livers can reduce, but not eliminate, campylobacters.  

Campylobacter in Danish broiler flocks.

This study was conducted to identify risk factors for the occurrence of Campylobacter in Danish broiler flocks.  The following factors were found to be significantly associated with the occurrence of Campylobacter in the broiler flocks: old broiler houses, late introduction of whole wheat in the feed, relatively high broiler age at slaughter, improper rodent control, large number of chimneys on the broiler house, farm located in an area with a high density of cattle farms, having more than one broiler house on the farm, and improper storage of wheat.  Results concerning chimneys may be explained by easier access that flies have to broiler houses.

Fly Screens Reduce Campylobacter in Broiler Chickens

The year-round and long-term effects of fly screens in 10 broiler chicken houses (99 flocks) were studied in Denmark.  Prevalence of Campylobacter spp.–positive flocks was significantly reduced, from 41.4% during 2003–2005 (before fly screens) to 10.3% in 2006–2009 (with fly screens).  In fly screen houses, Campylobacter spp. prevalence did not peak during the summer.  Nationally, prevalence of Campylobacter spp.–positive flocks in Denmark could have been reduced by an estimated 77% during summer had fly screens been part of biosecurity practices.  These results imply that fly screens might help reduce prevalence of campylobacteriosis among humans, which is closely linked to Campylobacter spp. prevalence among broiler chicken flocks.

Farm and slaughterhouse characteristics affecting the occurrence of Salmonella and Campylobacter in the broiler supply chain.

 

Farm- and slaughterhouse-specific characteristics were tested for their effect on Campylobacter and Salmonella prevalence at different stages of the broiler supply chain. The country of origin of the broiler farm had a significant effect on the prevalence of Salmonella and Campylobacter at slaughterhouse arrival. The feeding company delivering to the farm also showed a significant effect on the occurrence of both pathogens at departure from the broiler farm. The prevalence of Campylobacter decreased with an increasing number of birds per flock, whereas the prevalence of Salmonella increased with an increasing number of birds per flock. The number of flocks processed within a specific slaughterhouse was not associated with an increased or decreased prevalence of Campylobacter and Salmonella. Poult Sci.91(9):2376-81, 2012.

Risk factors for Campylobacter infection in Danish broiler chickens.

 

Data from the Quality Assurance System in Danish Broiler Production were analyzed to identify within farm biosecurity- and management-related risk factors for Campylobacter infection in Danish broiler flocks. The analysis revealed that flocks had a higher risk of acquiring positive infection status during summer time: odds ratio = 12.59 (95% CI: 6.79-23.36) and when more than one person entered the broiler house: odds ratio = 2.03 (95% CI: 1.19-3.84).  Furthermore, there was a higher risk of a positive infection status if the test result of the farm for the previous flock was positive: odds ratio = 1.80 (95% CI: 1.22-2.63), if the broiler houses were built before and during 1990: odds ratio = 1.60 (95% CI: 1.17-2.18), and if the average slaughter age of the birds was more than 35 d: odds ratio = 1.33 (95% CI: 1.02-1.76). Poult Sci.91(10):2701-9, 2012.  

Control of Campylobacter jejuni in chicken breast meat by irradiation combined with modified atmosphere packaging including carbon monoxide.

 

Cross-contamination of Camylobacter occurs in many poultry processing plants, and can occur in the kitchens and refrigerators of consumers. Irradiation in combination with high-CO2 + CO modified atmosphere packaging (MAP) was investigated in this study for the control of Campylobacter jejuni in chicken breast meat.  C. jejuni survived in both vacuum and high-CO2 MAP through 6 weeks of refrigerated storage.  Irradiation was effective for eliminating C. jejuni from meat or poultry packaged in vacuum or MAP, and should reduce the chance of cross-contamination in retail stores or home kitchens.  However, irradiated off-odor and sour aroma were observed for raw, irradiated chicken breast packaged with either vacuum or MAP. Therefore, additional means to mitigate quality changes appear necessary for these products. J Food Prot.75(10):1728-33, 2012.  

Evidence for horizontal and vertical transmission in Campylobacter passage from hen to her progeny.

 
For more than a decade, there has been an ongoing national and international controversy about whether Campylobacter can pass from one generation of poultry to the next via the fertile egg.  The authors recognize that there are numerous sources of Campylobacter entry into flocks of commercial poultry (including egg transmission), yet the environment is often cited as the only source. This paper lists published research globally that refutes this contention.  Egg passage can mean more than vertical, transovarian transmission.  Fecal bacteria, including Campylobacter, can contaminate the shell, shell membranes, and albumen of freshly laid fertile eggs. This contamination is drawn through the shell by temperature differential, aided by the presence of moisture (the "sweating" of the egg); then, when the chick emerges from the egg, it can ingest bacteria such as Campylobacter, become colonized, and spread this contamination to flock mates in the grow house. J Food Prot.75(10):1896-902, 2012.  

Screening for lactic acid bacteria capable of inhibiting Campylobacter jejuni in in vitro simulations of the broiler chicken caecal environment.

 

Consumption of improperly prepared poultry products and cross contamination are among the main causes of human campylobacteriosis. The aim of this study was to identify lactic acid bacterial (LAB) strains capable of inhibiting C. jejuni growth.  The best inhibition results were obtained when Enterococcus faecalis was inoculated before the C. jejuni strain, lowering C. jejuni counts at least one log compared to a positive control. This effect was already observed 6 h after C. jejuni inoculation. Benef Microbes.3(4):299-308, 2012.

Survival of Campylobacter jejuni in naturally and artificially contaminated laying hen feces.

 

Infected laying hens regularly excrete large amounts of Campylobacter jejuni with their feces, which represent a reservoir of infection within the flock and for animals in the region. Survival times of culturable C. jejuni ranged from 72 to 96 h in artificially inoculated feces and varied from 120 to 144 h in naturally colonized flocks. Contaminated fresh feces are an important reservoir of C. jejuni, representing a permanent source of infection over at least 6 d after excretion.  Fresh feces may potentially transmit the agent within and between flocks during that period. This 6-d span should be considered when poultry manure is applied to land as organic fertilizer. Poult Sci.92(2):364-9, 2013.

Use of plant-derived antimicrobials for improving the safety of poultry products.

Chickens are the reservoir hosts of Salmonella Enteritidis and Campylobacter jejuni, with their intestinal colonization being the most significant factor causing contamination of meat and eggs.  This paper discusses the potential use of plant-derived, GRAS (generally recognized as safe)-status molecules, caprylic acid, trans-cinnamaldehyde, eugenol, carvacrol, and thymol as feed supplements for reducing cecal populations of Salmonella Enteritidis and C. jejuni in chickens. Poult Sci.92(2):493-501, 2013.  

Campylobacter infection in poultry-processing workers, virginia, USA, 2008-2011

During a health hazard evaluation, 29 cases of laboratory-diagnosed Campylobacter infection among workers at a poultry-processing plant were investigated. Most infected employees worked at the plant <1 month, worked as live hangers, and lived at a state-operated center. To lessen the infection risk, improvements to engineering and administrative controls at the plant were recommended. Emerg Infect Dis. 19(2):286-8, 2013. 

A longitudinal study on thermophilic Campylobacter spp. in commercial turkey flocks in northern Italy: occurrence and genetic diversity.  

Poultry are recognized as a main reservoir of thermophilic campylobacters. Findings suggest that Italian commercial turkeys might be widely colonized by different genotypes of C. jejuni and C. coli and also suggest that differences in the distribution and epidemiologic dynamics of these microorganisms might occur among flocks. Avian Dis. 56(4):693-700, 2012. 

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