Campylobacter Colonization In Broiler Chickens Research Articles

Approaches to prevent and control Campylobacter spp. colonization in broiler chickens: a review.

Campylobacter, Gram-negative bacteria, is the most common cause of acute bacterial enteritis in human beings, both in developing and developed countries. It is believed that poultry, in particular broiler chickens, is the main host of human infection with Campylobacter. Handling and consumption of contaminated chicken meat are the usual modes of transmission. Prevention and reduction of Campylobacter colonization in poultry farms will cut off the road of infection transmission to humans throughout the food chain. With the incidence of antibiotic resistance and with growing concern about superbugs, the search for natural and safe alternatives will considerably increase in the coming years. In this review, we will discuss the prevalence and risk factors of Campylobacter colonization in broiler chickens and sources of infection. This review also provides extensive and recent approaches to prevent and control Campylobacter colonization in broiler chickens, including biosecurity measures, natural feed/drinking water additives with antimicrobial properties, bacteriocins, bacteriophages, antimicrobial peptides, and vaccination strategies to prevent and control the incidence of human campylobacteriosis.

(-)-α-Pinene reduces quorum sensing and Campylobacter jejunicolonization in broiler chickens.

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.

Effect of yeast mannan-rich fractions on reducing Campylobacter colonization in broiler chickens

SUMMARY Campylobacteriosis is considered to be the most frequently reported cause of zoonotic illness globally, with poultry being the main source of infection. Reducing the colonization level of Campylobacter spp. in broilers entering the processing unit could make an effective contribution at reducing the incidence of zoonotic transmission of this pathogen. It is essential to search for new, natural, and sustainable strategies to reduce the incidence of this bacterium in the broiler cecum. The aim of this study was to examine whether dietary supplementation of broilers with 3 different yeast mannan-rich fraction (MRF) supplements (supplements 1 to 3) reduced the level of natural Campylobacter spp. colonization in the broiler cecum. Birds were allowed to naturally become colonized with Campylobacter spp. from the environment. Weight gains and feed conversion ratios were measured throughout production. All 3 MRF based supplements resulted in higher weight gains over 35 d when compared with the control. Broiler pens were tested at d 21 post hatch using the boot swab method and confirmed Campylobacter spp. presence in the flock. At d 35 post hatch, colonization levels were measured using serial dilution plate counts and quantitative polymerase chain reaction (qPCR) of cecal material. Enumeration of Campylobacter colonization level in cecal content by qPCR showed that both supplement 2 and supplement 3 significantly reduced the levels of Campylobacter spp. colonization in the broiler cecum at 35 days. In conclusion, under the conditions of this study, MRF based supplements significantly reduced Campylobacter colonisation levels in the broiler cecum while also offering improvements in weight gain.

Application of β-Resorcylic Acid as Potential Antimicrobial Feed Additive to Reduce Campylobacter Colonization in Broiler Chickens.

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, β-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 μl/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.

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.

The efficacy of a commercial competitive exclusion product on Campylobacter colonization in broiler chickens in a 5-week pilot-scale study

The efficacy of the commercial competitive exclusion product Broilact against Campylobacter jejuni was evaluated in broiler chickens in a 5-week pilot-scale study. Newly-hatched broiler chicks were brought from a commercial hatchery. After arrival 50 seeder chicks were challenged orally with approximately 103 cfu of C. jejuni, wing marked, and placed back in a delivery box and moved to a separate room. The rest of the chicks (contact chicks) were placed in floor pens, 100 chicks per pen. Birds in two pens were treated orally on the day of hatch with the commercial competitive exclusion (CE) product Broilact, and three pens were left untreated. The following day 10 seeder chicks were introduced into the Broilact treated and untreated control pens. One pen was left both untreated and unchallenged (0-control). Each week the ceca of 10 contact chicks and one seeder chick were examined quantitatively for Campylobacter. The treatment prevented or significantly reduced the colonization of the challenge organism in the ceca during the two first weeks; the percentage of colonized birds being 0% after the first week and 30% after the second week in the Broilact treated groups but was 100% in the control groups the entire 5-week rearing period. During the third rearing week the proportion of Campylobacter positive birds started to increase in the treated pens, being 80% after the third week and 95 and 90% after the fourth and fifth rearing weeks, respectively. Similarly the average count of Campylobacter in the cecal contents of the Broilact treated chicks started to increase, the difference between the treated and control chicks being 1.4 logs at the end of the rearing period. Although the protective effect was temporary and occurred only during the first two weeks of the rearing period, the results of this study support the earlier observations that CE flora designed to protect chicks from Salmonella may also reduce Campylobacter colonization of broiler chickens.

The efficacy of selected probiotic and prebiotic combinations in reducing Campylobacter colonization in broiler chickens

Campylobacter is one of the leading causes of foodborne illness worldwide and is associated with consumption of poultry products. One potential strategy to reduce Campylobacter colonization in poultry is the use of probiotics. In an attempt to reduce Campylobacter in poultry, we isolated 117 GRAS (generally recognized as safe) bacterial isolates from the ceca of healthy birds and evaluated their efficacy against Campylobacter, using a soft agar overlay technique. Twenty-six isolates (Bacillus and Lactobacillus spp.) with greatest ability to inhibit Campylobacter in vitro, were tested in birds. In these studies, bacterial isolates were administered orally on day-of-hatch and, chicks were challenged with a four-strain mixture of wild type C. jejuni (∼106 CFU/mL) on day 7. Cecal samples were collected on day 14 for Campylobacter enumeration. Out of 26 isolates, 3 isolates demonstrated a reduction in Campylobacter counts (1 to 2 logs). In an attempt to improve the efficacy of these 3 isolates, follow-up studies were conducted with various doses of 2 prebiotics (fructooligosaccharide [FOS] or mannan oligosaccharide [MOS]) in the feed. Campylobacter counts were not reduced for any of the FOS treatments (0.125%, 0.25%, or 0.5%) or the MOS treatments (0.04%, 0.08%, or 0.16%), but were reduced for the combination of isolate 3 with 0.04% MOS in feed. The results of this study indicate that the selection and administration of bacterial isolates in combination with selected prebiotics may reduce enteric Campylobacter counts in preharvest poultry.

Intracloacal Inoculation, an Effective Screening Method for Determining the Efficacy of Probiotic Bacterial Isolates against Campylobacter Colonization in Broiler Chickens

Campylobacter is a leading cause of foodborne illness worldwide. It is common in poultry, and human infections are often associated with consumption of contaminated poultry products. One strategy to reduce Campylobacter colonization in poultry is the use of oral probiotics, but this produces variable results, possibly because the probiotics are destroyed in the stomach's acidic environment. Protection (e.g., encapsulation) of isolates may overcome this problem, but there is no assurance that these isolates will have efficacy in the lower gastrointestinal tract. Therefore, screening candidate isolates by directly placing them in the lower intestinal tract via cloacal inoculation may eliminate the time and expense of encapsulating ineffective isolates. Thus, the purpose of this study was to collect bacterial isolates with anti-Campylobacter activity in vitro and evaluate their efficacy in vivo upon either oral or intracloacal administration. Bacterial isolates were collected from healthy birds and were evaluated for efficacy against C. jejuni in vitro. Isolates having generally regarded as safe status and demonstrating in vitro anti-Campylobacter properties were evaluated after oral or intracloacal inoculation into chicks on day 1 (n = 10 birds per isolate per route of administration). On day 7, birds were dosed by oral gavage with a four-strain mixture of wild-type Campylobacter containing at least 1 x 107 CFU/ml organisms. On day 14, birds were euthanized and the ceca were collected aseptically for Campylobacter enumeration. When dosed orally, only one isolate had a 1-log reduction in cecal Campylobacter counts, whereas when administered intracloacally, six of these isolates produced a 1- to 3-log reduction in cecal Campylobacter counts in 14-day-old chickens. These results support the strategy of evaluating the efficacy of potential probiotic isolates via cloacal inoculation prior to undergoing the effort of encapsulating isolates for oral administration.

The Efficacy of the Natural Plant Extracts, Thymol and Carvacrol against Campylobacter Colonization in Broiler Chickens

AbstractCampylobacter is a leading worldwide cause of foodborne illness associated with consumption of poultry products. Unfortunately, most preharvest treatments fail to reduce this enteric foodborne pathogen in poultry. The efficacy of natural plant extracts, such as thymol and carvacrol, has efficacy against other enteric pathogens but has not been evaluated against Campylobacter. To accomplish this, day old broiler chicks (n = 10 chicks/dose) were fed 0% (controls) or thymol or carvacrol or combinations of these compounds in feed in four different trials. Birds were orally challenged with Campylobacter jejuni at day 3 and at day 10, cecal samples were collected for Campylobacter enumeration. Campylobacter counts were reduced for 0.25% thymol (trial 1), 1% carvacrol or 2% thymol (trial 2) treatments, or a combination of both thymol and carvacrol at 0.5% (trial 3) in this study (P &lt; 0.05). These results support supplementation of these compounds in feed to reduce Campylobacter colonization in chickens.Practical ApplicationsCampylobacter is one of the major causes of foodborne enteritis worldwide, and the majority of human campylobacteriosis cases were reported to be associated with improper handling and/or consumption of undercooked poultry . Because poultry are the major contributors for human infections, eliminating or reducing Campylobacter in poultry would greatly reduce the risk of campylobacteriosis in humans. Many strategies have been tried to eliminate Campylobacter with limited success. Considering the increasing consumer demand for natural, safer food products, free from synthetic residues, use of natural compounds with proven antimicrobial efficacy appears to be a promising strategy to control Campylobacter in poultry. In the present study we evaluated the in vivo efficacy of different concentrations and combinations of two natural compounds, thymol and carvacrol, against Campylobacter colonization in broiler chickens.

Evaluation of nanoparticle-encapsulated outer membrane proteins for the control of Campylobacter jejuni colonization in chickens

Numerous vaccination strategies have been evaluated to develop effective vaccines against Campylobacter jejuni colonization in poultry but with limited success. The following experiments were conducted to investigate the effect of biodegradable and biocompatible poly (lactide-co-glycolide) nanoparticle (NP) encapsulated outer membrane proteins (OMP) of C. jejuni. Chickens were vaccinated with different routes [subcutaneous (s/c) or oral] and doses (25, 125, or 250 µg) of candidate nanoparticle vaccine with appropriate control groups. Serum and cloacal fecal samples were taken at regular intervals of time, and the birds were euthanized 7 d postchallenge with C. jejuni. The results were interpreted based on anti-OMP immunoglobulin response in chicken and intestinal colonization of C. jejuni. The C. jejuni colonization in cecal and cloacal contents at 7 d postchallenge was below the detection limit in the s/c vaccinated groups, but the other groups demonstrated varying degrees of colonization. The serum IgA was higher in the group vaccinated s/c with OMP only compared with the rest of the groups. The serum- and fecal-IgY titers were consistently higher in the s/c vaccinated groups (with or without NP) than the rest of the groups. Elevated levels of OMP specific serum antibodies correlated with below the limit of detection levels of Campylobacter colonization in broiler chickens receiving 125 μg of OMP alone and the OMP+NP vaccine s/c. In conclusion, the s/c route of vaccination with or without NP encapsulated OMP of C. jejuni may serve as a candidate vaccine for control of C. jejuni colonization in chickens.

In vivo broiler experiments to assess anti-Campylobacter jejuni activity of a live Enterococcus faecalis strain

Bacterial gastroenteritis caused by thermotolerant Campylobacter species, mainly Campylobacter jejuni, has been the most reported zoonotic disease in many developed countries in recent years. Reducing Campylobacter shedding on the farm could result in a reduction of the number of campylobacteriosis cases. In 2 independent broiler seeder experiments, in which broiler chickens were orally inoculated with 2 amounts of Enterococcus faecalis MB 5259, we established whether a live E. faecalis strain was capable of reducing cecal Campylobacter colonization in broiler chickens. In previous in vitro experiments it has been demonstrated that this E. faecalis MB 5259 displays anti-Campylobacter activity. The effect of pH and bile salts on E. faecalis MB 5259 showed that growth and survival of E. faecalis MB 5259 can be impaired during passage through the gastrointestinal tract of broiler chickens. Despite these results E. faecalis MB 5259 was capable of colonizing the broiler ceca. Contrary to the in vitro experiments, in which E. faecalis MB 5259 inhibited C. jejuni MB 4185 growth, no inhibition was observed in the in vivo experiments independent of the inoculum size.

The cinnamon-oil ingredient trans-cinnamaldehyde fails to target Campylobacter jejuni strain KC 40 in the broiler chicken cecum despite marked in vitro activity.

Campylobacter jejuni is the most common bacterial cause of diarrheal disease in humans worldwide, with poultry products being a major source. Therefore, strategies to decrease Campylobacter colonization during primary production might aid in reducing the number of human campylobacteriosis cases. Several plant-derived compounds have been reported to possess anti-Campylobacter properties in vitro, so they could be promising candidates to reduce Campylobacter colonization in broiler chickens. To test this hypothesis, selected plant-derived antimicrobials (caffeic, gallic, protocatechuic, and vanillic acids, epigallocatechin gallate, trans-cinnamaldehyde, and thymol) were screened for anti-Campylobacter activity by determining MICs and setting up time-kill curves for C. jejuni strain KC 40. These experiments revealed marked antibacterial activity, especially for the cinnamon oil ingredient trans-cinnamaldehyde (CIN). This compound was tested in a broiler chick seeder model; it was added to the feed in coated form at an effective concentration of 0.3 % from day-of-hatch for the entire 22-day duration of the experiment. At 14 days of age, one-third of the birds were inoculated with C. jejuni strain KC 40 and served as seeders. CIN was not able to reduce cecal Campylobacter colonization in this model, which was confirmed in a cecal loop experiment. Despite CIN concentrations much higher than the MIC, C. jejuni numbers were not reduced compared with those in nontreated ceca at 2 and 24 h after injection. In conclusion, this study shows a marked discrepancy between in vitro and in vivo activity of CIN against C. jejuni strain KC 40.

Intestinal mucus protects Campylobacter jejuni in the ceca of colonized broiler chickens against the bactericidal effects of medium-chain fatty acids

Campylobacter jejuni is the most common cause of bacterial-mediated diarrheal disease worldwide. Because poultry and poultry products are a major source of C. jejuni infections in humans, efforts should be taken to develop strategies to decrease Campylobacter shedding during primary production. For this purpose, the efficacy of medium-chain fatty acids (MCFA) as feed additives to control C. jejuni colonization in broiler chickens was analyzed. First, the antimicrobial activity of the MCFA caproic, caprylic, and capric acid on C. jejuni was evaluated in vitro. Minimal inhibitory concentrations were 0.25 mM for caproic and 0.5 mM for caprylic and capric acids at pH 6.0 and 4 mM for all 3 compounds at pH 7.5. Time-kill curves revealed strong bactericidal properties of the tested compounds toward C. jejuni at pH 6.0. Concentrations as low as 4 mM caprylic and capric acids and 16 mM caproic acid killed all bacteria within 24 h. Capric acid had the highest activity, with concentrations of 4 mM killing all bacteria within the hour. Together these data show a profound bactericidal, dose-dependent activity of the tested MCFA toward C. jejuni in vitro. For this reason, the effect of these 3 MCFA on C. jejuni was evaluated in vivo. The addition of any of the acids to the feed, from 3 d before euthanization, was not capable of reducing cecal Campylobacter colonization in 27-d-old broilers experimentally infected with C. jejuni at 15 d of age. Using a cecal loop model, sodium caprate was not able to reduce cecal Campylobacter counts. When time-kill curves were conducted in the presence of chick intestinal mucus, capric acid was less active against C. jejuni. At 4 mM, all bacteria were killed only after 24 h. Thus, despite the marked bactericidal effect of MCFA in vitro, supplementing these acids to the feed does not reduce cecal Campylobacter colonization in broiler chickens under the applied test conditions, probably due to the protective effect of the mucus layer.

Bacteriocins Reduce Campylobacter Colonization and Alter Gut Morphology in Turkey Poults ,

Campylobacter is a leading cause of foodborne illness in the United States. Recent evidence has demonstrated that bacteriocins produced by Bacillus circulans and Paenibacillus polymyxa reduce cecal Campylobacter colonization in broiler chickens infected with Campylobacter jejuni. As Campylobacter coli is the most prevalent Campylobacter isolate recovered in turkeys, the objectives of the present study were to evaluate the efficacy of these bacteriocins against C. coli colonization and their influence on the gastrointestinal architecture of young turkeys. In 3 separate trials, a total of 135 day-of-hatch poults (n = 45/trial) were orally challenged on d 3 with approximately 106 cfu of a mixture of 3 C. coli isolates. Immediately before bacteriocin treatment (d 10), cecal Campylobacter concentrations averaged 1.1 × 107 cfu/ g of cecal contents (n = 15/trial). On d 10 to 12 posthatch, 2 bacteriocin treatment groups were given free access to feed supplemented with purified, microencapsulated bacteriocins, whereas the positive control treatment group had access to untreated feed (n = 10/treatment group per trial). At the end of the 3-d dosing period, ceca and duodenal loops were collected for analysis. In each of the 3 separate trials, treatment with bacteriocin eliminated detectable ceca Campylobacter concentrations (detection limit, 1 × 102 cfu/g of cecal contents) vs. controls (1.0 × 106 cfu of Campylobacter/g of cecal contents). Duodenum crypt depth and goblet cell numbers were also reduced in turkeys treated with either bacteriocin vs. controls (P < 0.05). The dynamic reduction in crypt depth and goblet cell density in turkeys dosed with bacteriocin may provide clues to how bacteriocins inhibit enteric Campylobacter.

Sources of Campylobacter colonization in broiler chickens.

Campylobacter jejuni and its close relative Campylobacter coli (hereafter jointly referred to as C. jejuni or campylobacters) are gram-negative, thermophilic, obligate microaerophilic bacteria that are ubiquitous in temperate environments. Both species colonize the intestinal mucosa of most warm-