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Bacteriophage therapy to reduce Campylobacter jejuni colonization of broiler chickens.

ABSTRACT: Colonization of broiler chickens by the enteric pathogen Campylobacter jejuni is widespread and difficult to prevent. Bacteriophage therapy is one possible means by which this colonization could be controlled, thus limiting the entry of campylobacters into the human food chain. Prior to evaluating the efficacy of phage therapy, experimental models of Campylobacter colonization of broiler chickens were established by using low-passage C. jejuni isolates HPC5 and GIIC8 from United Kingdom broiler flocks. The screening of 53 lytic bacteriophage isolates against a panel of 50 Campylobacter isolates from broiler chickens and 80 strains isolated after human infection identified two phage candidates with broad host lysis. These phages, CP8 and CP34, were orally administered in antacid suspension, at different dosages, to 25-day-old broiler chickens experimentally colonized with the C. jejuni broiler isolates. Phage treatment of C. jejuni-colonized birds resulted in Campylobacter counts falling between 0.5 and 5 log10 CFU/g of cecal contents compared to untreated controls over a 5-day period postadministration. These reductions were dependent on the phage-Campylobacter combination, the dose of phage applied, and the time elapsed after administration. Campylobacters resistant to bacteriophage infection were recovered from phage-treated chickens at a frequency of <4%. These resistant types were compromised in their ability to colonize experimental chickens and rapidly reverted to a phage-sensitive phenotype in vivo. The selection of appropriate phage and their dose optimization are key elements for the success of phage therapy to reduce campylobacters in broiler chickens.

SUBMITTER: Loc Carrillo C

PROVIDER: S-EPMC1287621 | biostudies-literature | 2005 Nov

REPOSITORIES: biostudies-literature

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Bacteriophage therapy to reduce Campylobacter jejuni colonization of broiler chickens.

Loc Carrillo C C Atterbury R J RJ el-Shibiny A A Connerton P L PL Dillon E E Scott A A Connerton I F IF

Applied and environmental microbiology 20051101 11

Colonization of broiler chickens by the enteric pathogen Campylobacter jejuni is widespread and difficult to prevent. Bacteriophage therapy is one possible means by which this colonization could be controlled, thus limiting the entry of campylobacters into the human food chain. Prior to evaluating the efficacy of phage therapy, experimental models of Campylobacter colonization of broiler chickens were established by using low-passage C. jejuni isolates HPC5 and GIIC8 from United Kingdom broiler ...[more]

PMID: 16269681

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Project description:Campylobacter jejuni is one of the most prevalent causes of bacterial gastroenteritis worldwide, and it is largely associated with consumption of contaminated poultry. Current Campylobacter control measures at the poultry production level remain insufficient, and hence there is the need for alternative control strategies. We evaluated the potential of the monoterpene (-)-α-pinene for control of C. jejuni in poultry. The antibacterial and resistance-modulatory activities of (-)-α-pinene were also determined against 57 C. jejuni strains. In addition, the anti-quorum-sensing activity of (-)-α-pinene against C. jejuni NCTC 11168 was determined for three subinhibitory concentrations (125, 62.5, 31.25 mg/L) over three incubation times using an autoinducer-2 bioassay based on Vibrio harveyi BB170 bioluminescence measurements. The effects of a subinhibitory concentration of (-)-α-pinene (250 mg/L) on survival of C. jejuni, and in combination with enrofloxacin on fluoroquinolone resistance development in C. jejuni, were determined in a broiler chicken model, by addition of (-)-α-pinene to the broiler water supply. The reduction of C. jejuni numbers by (-)-α-pinene was further determined in broiler chickens that were colonized with either fluoroquinolone-susceptible or -resistant strains, by direct gavage treatment. We observed weak in vitro antimicrobial activity for (-)-α-pinene alone (MIC >500 mg/L), but strong potentiating effects on antibiotics erythromycin and ciprofloxacin against different Campylobacter strains (>512 fold change). After 24 h of treatment of C. jejuni with (-)-α-pinene, its quorum-sensing signaling was reduced by >80% compared to the untreated control. When given in the drinking water, (-)-α-pinene did not show any significant inhibitory effects on the level of C. jejuni in the colonized chickens, and did not reduce fluoroquinolone resistance development in combination with enrofloxacin. Conversely, when (-)-α-pinene was administered by direct gavage, it significantly reduced the number of fluoroquinolone susceptible C. jejuni in the colonized broiler chickens. These results demonstrate that (-)-α-pinene modulates quorum-sensing in Campylobacter, potentiates antibiotics against different Campylobacter strains, and reduces Campylobacter colonization in broiler chickens.

Project description:Campylobacter is one of the major foodborne pathogens that result in severe gastroenteritis in humans, primarily through consumption of contaminated poultry products. Chickens are the reservoir host of Campylobacter, where the pathogen colonizes the ceca, thereby leading to contamination of carcass during slaughter. A reduction in cecal colonization by Campylobacter would directly translate into reduced product contamination and risk of human infections. With increasing consumer demand for antibiotic free chickens, significant research is being conducted to discover natural, safe and economical antimicrobials that can effectively control Campylobacter colonization in birds. This study investigated the efficacy of in-feed supplementation of a phytophenolic compound, ?-resorcylic acid (BR) for reducing Campylobacter colonization in broiler chickens. In two separate, replicate trials, day-old-chicks (Cobb500; n = 10 birds/treatment) were fed with BR (0, 0.25, 0.5, or 1%) in feed for a period of 14 days (n = 40/trial). Birds were challenged with a four-strain mixture of Campylobacter jejuni (?106 CFU/ml; 250 ?l/bird) on day 7 and cecal samples were collected on day 14 for enumerating surviving Campylobacter in cecal contents. In addition, the effect of BR on the critical colonization factors of Campylobacter (motility, epithelial cell attachment) was studied using phenotypic assay, cell culture, and real-time quantitative PCR. Supplementation of BR in poultry feed for 14 days at 0.5 and 1% reduced Campylobacter populations in cecal contents by ?2.5 and 1.7 Log CFU/g, respectively (P < 0.05). No significant differences in feed intake and body weight gain were observed between control and treatment birds fed the compound (P > 0.05). Follow up mechanistic analysis revealed that sub-inhibitory concentration of BR significantly reduced Campylobacter motility, attachment to and invasion of Caco-2 cells. In addition, the expression of C. jejuni genes coding for motility (motA, motB, fliA) and attachment (jlpA, ciaB) was down-regulated as compared to controls (P < 0.05). These results suggest that BR could potentially be used as a feed additive to reduce Campylobacter colonization in broilers.

Project description:Using laboratory challenge experiments, we examined whether Campylobacter-specific maternal antibody (MAB) plays a protective role in young chickens, which are usually free of Campylobacter under natural production conditions. Kinetics of C. jejuni colonization were compared by infecting 3-day-old broiler chicks, which were naturally positive for Campylobacter-specific MAB, and 21-day-old broilers, which were negative for Campylobacter-specific MAB. The onset of colonization occurred much sooner in birds challenged at the age of 21 days than it did in the birds inoculated at 3 days of age, which suggested a possible involvement of specific MAB in the delay of colonization. To further examine this possibility, specific-pathogen-free layer chickens were raised under laboratory conditions with or without Campylobacter infection, and their 3-day-old progenies with (MAB(+)) or without (MAB(-)) Campylobacter-specific MAB were orally challenged with C. jejuni. Significant decreases in the percentage of colonized chickens were observed in the MAB(+) group during the first week compared with the MAB(-) group. These results indicate that Campylobacter-specific MAB plays a partial role in protecting young chickens against colonization by C. jejuni. Presence of MAB in young chickens did not seem to affect the development of systemic immune response following infection with C. jejuni. However, active immune responses to Campylobacter occurred earlier and more strongly in birds infected at 21 days of age than those infected at 3 days of age. Clearance of Campylobacter infection was also observed in chickens infected at 21 days of age. Taken together, these findings (i) indicate that anti-Campylobacter MAB contributes to the lack of Campylobacter infection in young broiler chickens in natural environments and (ii) provide further evidence supporting the feasibility of development of immunization-based approaches for control of Campylobacter infection in poultry.

Project description:Campylobacter jejuni is the leading cause of bacterial food-borne infection; chicken meat is its main source. C. jejuni is considered commensal in chickens based on experimental models unrepresentative of commercial production. Here we show that the paradigm of Campylobacter commensalism in the chicken is flawed. Through experimental infection of four commercial breeds of broiler chickens, we show that breed has a significant effect on C. jejuni infection and the immune response of the animals, although these factors have limited impact on the number of bacteria in chicken ceca. All breeds mounted an innate immune response. In some breeds, this response declined when interleukin-10 was expressed, consistent with regulation of the intestinal inflammatory response, and these birds remained healthy. In another breed, there was a prolonged inflammatory response, evidence of damage to gut mucosa, and diarrhea. We show that bird type has a major impact on infection biology of C. jejuni. In some breeds, infection leads to disease, and the bacterium cannot be considered a harmless commensal. These findings have implications for the welfare of chickens in commercial production where C. jejuni infection is a persistent problem. Importance: Campylobacter jejuni is the most common cause of food-borne bacterial diarrheal disease in the developed world. Chicken is the most common source of infection. C. jejuni infection of chickens had previously not been considered to cause disease, and it was thought that C. jejuni was part of the normal microbiota of birds. In this work, we show that modern rapidly growing chicken breeds used in intensive production systems have a strong inflammatory response to C. jejuni infection that can lead to diarrhea, which, in turn, leads to damage to the feet and legs on the birds due to standing on wet litter. The response and level of disease varied between breeds and is related to regulation of the inflammatory immune response. These findings challenge the paradigm that C. jejuni is a harmless commensal of chickens and that C. jejuni infection may have substantial impact on animal health and welfare in intensive poultry production:

Dataset Information

Bacteriophage therapy to reduce Campylobacter jejuni colonization of broiler chickens.

Publications

Bacteriophage therapy to reduce Campylobacter jejuni colonization of broiler chickens.

Similar Datasets

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