Colonization Of Broiler Chickens Research Articles

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.

Efficacy of a lactylate on production performance and intestinal health of broilers during a subclinical Clostridium perfringens infection

Clostridium perfringens, an α-toxin producing gram-positive bacterium, is an enteric pathogen for poultry. Because subclinical C. perfringens infections often result in damage of the intestinal mucosa, decreased nutrient digestion, and poor performance, efforts should be taken to find an effective strategy that controls overgrowth of C. perfringens. For this purpose, the efficacy of a sodium lauroyl lactylate (LauL) as a feed additive to prevent C. perfringens colonization in broilers was determined. First, the effect of LauL was compared with capric and lauric mono- and diglycerides (MDG) and capric and lauric free fatty acids in Clostridium-infected chickens. Clostridial lesion scoring at d 16 showed that MDG and LauL were both effective in reducing the severity of lesions. When taking into account results on BW gain and mortality, LauL was more effective than MDG. For this reason, a dose response study was made to determine the optimal dietary dosage of LauL. In this experiment, it was shown that a LauL dose higher than 0.15% should be used to expect positive effects on lesion severity and mortality. None of the LauL doses led to a significant better response on growth performance. In a third trial, efficacy of LauL was compared with commercial products that limit bacterial activity in the intestinal tract (Aromabiotic Poul 60) or coccidiosis (chemical coccidiostat, Clinacox). None of the products were able to reduce the number or severity of lesions, and no effect on production performance was observed. Thus, despite the clear positive effect seen in experiment 1, and in experiment 2 with LauL doses higher than 0.15%, supplementing this lactylate to the diet does not consistently reduce C. perfringens colonization in broiler chickens because no such effects were observed in experiment 3. These results, however, provide a scientific basis for future studies to further investigate lactylates as potential additives to reduce the severity of necrotic enteritis in broilers in a C. perfringens challenge model.

Prevention of intestinal Campylobacter jejuni colonization in broilers by combinations of in-feed organic acids

We have tested the effect of various combinations of formic acid and sorbate on Campylobacter jejuni colonization in broiler chickens to reduce the colonization of this zoonotic pathogen in broiler chicken flocks. Chickens were offered feed supplemented with different concentrations and combinations of formic acid and/or potassium sorbate. We found little or no effect on the Camp. jejuni colonization levels in chickens that were given feed supplemented with formic acid alone. A combination of 1.5% formic acid and 0.1% sorbate reduced the colonization of Camp. jejuni significantly, while a concentration of 2.0% formic acid in combination with 0.1% sorbate prevented Camp. jejuni colonization in chickens. This inhibition was replicated in two independent trials with a combination of three different Camp. jejuni strains. Our results show a novel and promising intervention strategy to reduce the incidence of Camp. jejuni in poultry products and to obtain safer food. To ensure food safety, a reduction of the carcass contamination with Camp. jejuni through reduced colonization of this pathogen in broiler chicken flocks is important. A range of organic acids as additives in feed and drinking water have already been evaluated for this purpose. However, no studies have yet shown a complete inhibition of Camp. jejuni colonization in broiler chickens.

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.

Salmonella in chicken: current and developing strategies to reduce contamination at farm level.

Salmonella is a human pathogen that frequently infects poultry flocks. Consumption of raw or undercooked contaminated poultry products can induce acute gastroenteritis in humans. Faced with the public health concerns associated with salmonellosis, the European Union has established a European regulation forcing member states to implement control programs aimed at reducing Salmonella prevalence in poultry production, especially at the primary production level. The purpose of the present review article is to summarize the current research and to suggest future developments in the area of Salmonella control in poultry, which may be of value to the industry in the coming years. The review will focus especially on preventive strategies that have been developed and that aim at reducing the incidence of Salmonella colonization in broiler chickens at the farm level. In addition to the usual preventive hygienic measures, other strategies have been investigated, such as feed and drinking water acidification with organic acids and immune strategies based on passive and active immunity. Modification of the diet by changing ingredients and nutrient composition with the intent of reducing a bird's susceptibility to Salmonella infection also has been examined. Because in ovo feeding accelerates small intestine development and enhances epithelial cell function, this approach could be an efficient tool for controlling enteric pathogens. Feed additives such as antibiotics, prebiotics, probiotics, and synbiotics that modify the intestinal microflora are part of another field of investigation, and their success depends on the additive used. Other control methods such as the use of chlorate products and bacteriophages also are under study.

Influence of different litter materials on cecal microbiota colonization in broiler chickens

A chicken growth study was conducted to determine if litter type influenced gut microbiota and performance in broilers. Seven bedding materials were investigated and included soft and hardwood sawdust, softwood shavings, shredded paper, chopped straw, rice hulls, and reused softwood shavings. Microbial profiling was done to investigate changes in cecal bacterial communities associated with litter material and age. Cecal microbiota were investigated at 14 and 28 d of age (n = 12 birds/litter material). At both ages, the cecal microbiota of chickens raised on reused litter was significantly (P < 0.05) different from that of chickens raised on any of the other litter materials, except softwood shavings at d 28. Cecal microbiota was also significantly different between birds raised on shredded paper and rice hulls at both ages. Age had a significant influence on cecal microbiota composition regardless of litter material. Similarity in cecal microbial communities among birds raised on the same litter treatment was greater at 28 d of age (29 to 40%) than at 14 d of age (25 to 32%). Bird performance on the different litter materials was measured by feed conversion ratio, live weight, and feed intake. Significant (P < 0.05) differences were detected in live weight at 14 d of age and feed intake at 14 and 28 d of age among birds (n = 160/treatment) raised on some of the different litter materials. However, no significant (P > 0.05) differences were observed in feed conversion ratio among birds raised on any of the 7 different litter materials at either 14 or 28 d of age. The type of litter material can influence colonization and development of cecal microbiota in chickens. Litter-induced changes in the gut microbiota may be partially responsible for some of the significant differences observed in early rates of growth; therefore, litter choice may have an important role in poultry gut health particularly in the absence of in-feed antibiotics.

Adhesion and Growth Inhibitory Effect of Chicken Egg Yolk Antibody (IgY) onSalmonella entericaSerovars Enteritidis and TyphimuriumIn Vitro

The protective effects of powder preparation of egg yolk immunoglobulin Y (IgY), specific to Salmonella Enteritidis and Salmonella Typhimurium outer membrane proteins (OMP), against these two Salmonella sp. serovars were investigated in vitro in two different assays: adhesion-prevention and growth-inhibition. The adhesion-prevention assay was conducted using polarized monolayers of the human intestinal epithelial Caco-2 cell line. First, the conditions of Salmonella adherence to Caco-2 cells were optimized, and interferences of bacteria with the transepithelial electrical resistance (TER) of fully differentiated Caco-2 cell monolayers and the lactate dehydrogenase release upon exposure of the cells to Salmonella were evaluated. Both Salmonella sp. serovars were able to adhere to Caco-2 cells and decreased TER. Results from the adhesion-prevention assay demonstrated that specific IgY reduced the decrease in TER of the infected Caco-2 cell monolayers and blocked the Salmonella sp. adhesion in a concentration-dependent manner (p < 0.05). Nonspecific IgY also exhibited an inhibitory effect on these two parameters, but to a lesser extent than that of the specific IgY (p < 0.05). The protective effect of nonspecific IgY could be attributed to the low-density lipoprotein component of the water-soluble fraction of egg yolks that may not have been eliminated during ultrafiltration. The growth-inhibition assay revealed that specific IgY had an inhibitory effect on the bacterial growth, markedly during the late exponential phase, whereas nonspecific IgY failed to do so. Taken together, these results suggest that the in vitro growth inhibitory effect of specific IgY on Salmonella spp. resulted from the specific binding activity of these IgY to Salmonella sp. OMP. Passive immunization with Salmonella sp. OMP-specific IgY could thus be useful to prevent Salmonella colonization in broiler chickens and the subsequent carcass contamination during processing.

Evaluation of Spray Application of a Lactobacillus-based Probiotic on Salmonella enteritidis Colonization in Broiler Chickens

3 Abstract: Spray application offers low-cost and efficient application of biologic and reduced concerns regarding diverse water quality and medicator/proportioner function. The objective of the present study was to evaluat e the spray application of a Lactobacillus-based probiotic on Salmonella enteritidis (SE ) colonization in broiler chickens. Day-of-hatch chicks were challenged with Salmonella enteritidis (SE) by oral gavage alone, challenged with SE and treated by coarse spray application of a commercially-available Lactic- acid bacterial probiotic (FM-Probiotic ), or challenged with SE and treated with B11 continuously in the TM Drinking Water (DW). Five days post-challenge, cecal tonsils were collected for presence or absence of SE. In Exp. 1, probiotic treatment by either spray or DW application significantly (p<0.05) reduced SE recovery (55% and 50% respectively; controls 85%) when chicks were held for 8h prior to challenge and placement. Similarly, when probiotic spray treatment or water treatment and challenge occurred simultaneously, with placement 8h after treatment, a marked and significant reduction of SE recovery was noted after 5d (10% and 40% respectively, controls 55%). In Exp. 2, when probiotic spray treatment and challenge occurred simultaneously, with placement 8h after treatment, a significant reduction of SE recovery was again noted in both the spray and DW application (80% controls, 15% spray, 15% DW). Taken together, these results suggest that spray application of this probiotic, when performed in the manner described above, can be effective for protection of chicks against Salmonella infection.

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-

Comparison of Mucosal Competitive Exclusion and Competitive Exclusion Treatment to Reduce Salmonella and Campylobacter spp. Colonization in Broiler Chickens

Control of Salmonella spp. during the earliest phases of broiler production may provide the best opportunity to reduce human pathogens on processed broiler carcasses. Application of the “Nurmi concept” has been demonstrated to be an effective means in reducing Salmonella colonization among broiler chicks. In 1989, Aho et al. developed a competitive exclusion (CE) culture for control of Salmonella spp., whereas a mucosal competitive exclusion culture (MCE) developed in the United States was originally created to control Campylobacter colonization (Stern et al., 1995). The major differences in the two patents were the higher level of anaerobic culture required, the degree of epithelial scraping and washing of the ceca, media used for subculturing, and the culture incubation temperatures (35 C vs. 42 C). The CE and MCE were compared for efficacy in reducing Salmonella and Campylobacter colonization in broiler chicks. Nine adult birds (three for each of three replicates) were slaughtered, and each of a bird's paired ceca were used to produce corresponding antagonistic microflora, which were administered to day-of-hatch chicks. The chicks (a total of 210) were challenged 24 h later with Salmonella and Campylobacter and were killed 1 wk later, and levels of the pathogens were determined. Ninety CE-treated birds were significantly more colonized by Salmonella typhimurium than those 90 chicks treated with the MCE microflora (3.97 log 10 cfu/g cecal contents vs. 1.25 log 10 cfu/g cecal contents). Also, Campylobacter spp. colonization of these birds was significantly higher for CE-treated birds when compared with MCE-treated birds (6.96 log 10 cfu/g cecal contents vs. 5.03 log 10 cfu/g cecal contents). These results can be useful in developing intervention strategies to reduce chicken colonization by Salmonella and Campylobacter.

Dosage Titration of a Characterized Competitive Exclusion Culture To Inhibit Salmonella Colonization in Broiler Chickens during Growout

Broiler chicks were spray treated on the day of hatch with titrated dosages (106, 107, or 108 anaerobic CFU) of a characterized competitive exclusion culture (CF3) and challenged orally on day 3 with 104 CFU of Salmonella typhimurium. On day 10, cecal contents from control and CF3-treated chicks were cultured for S. typhimurium to determine the minimal efficacious dosage of the CF3 culture. The experiment was repeated in three replicated trials. Resistance to Salmonella cecal colonization was dosage related and progressively enhanced at the 107- and 108-CFU dosages compared with the 106-CFU dosage. The 107-CFU dosage was selected as the minimal effective dosage and evaluated for efficacy during a 43-day broiler growout study. Six hundred broilers were spray treated on the day of hatch and compared with 600 Controls. One-half of the control and CF3-treated birds were challenged orally on day 3 with 104 CFU of S. typhimurium and designated “seeders.” The remaining unchallenged birds were designated “contacts.” Compared with the Controls, the recovery of Salmonella cells from the ceca of the CF3-treated broilers was significantly decreased (P < 0.01) in the challenged seeders on days 21 and 43 of growout. Salmonella contamination of floor pen litter was significantly reduced (P < 0.05) in pens of CF3-treated birds compared with Controls. The transmission of Salmonella cells from seeder to contact birds in the same pens was decreased significantly (P < 0.01). The results indicated that treatment of broiler chicks on the day of hatch with the 107-CFU dosage of CF3 culture effectively increased resistance to S. typhimurium challenge during growout to market age.

Effect of Dietary Lactose and Cell Concentration on the Ability of a Continuous-Flow-Derived Bacterial Culture to Control Salmonella Cecal Colonization in Broiler Chickens

The effect of dietary lactose and of cell concentration of a continuous-flow (CF) derived bacterial culture on Salmonella typhimurium cecal colonization in 10-d-old broiler chickens was examined. One-day-old chicks were provided 1) no CF culture and the control diet; 2) no culture and a 2% lactose diet; 3) CF culture (108 or 1011 anaerobic cfu) and control diet; or 4) CF culture (108 or 1011 anaerobic cfu) and 2 to 4% lactose diet. All groups were challenged orally with 104S. typhimurium at 3 d of age. Salmonella typhimurium growth in cecal contents was significantly decreased (P < .05) at 10 d of age when 2% lactose was used in combination with CF culture containing 108 or 1011 anaerobic cfu. The protection factor (log10Salmonella control diet divided by log10Salmonella treatment group) for these treatment groups was 2.49 and 9.26, respectively. Results indicate that birds treated with CF culture and maintained on 2% dietary lactose are protected against S. typhimurium colonization. Additionally, inoculating birds with CF culture containing a higher concentration of anaerobic colony-forming units resulted in a substantially higher protection factor.

Effect of a Defined Continuous-Flow Derived Bacterial Culture and Dietary Lactose on Salmonella typhimurium Colonization in Broiler Chickens

A defined bacterial culture protective against Salmonella typhimurium cecal colonization in broiler chicks was derived utilizing a continuous-flow (CF) culture apparatus. Chicks receiving the CF culture in combination with a diet containing dietary lactose were protected against cecal colonization by S. typhimurium. The culture consisted of a mixture of gram-positive and gram-negative facultative and strictly anaerobic bacteria. The isolates were identified as Enterococcus avium, two strains of Enterococcus faecalis (designated A and B), Lactococcus lactis, Lactobacillus animalis, a Lactobacillus that could not be identified to species level (designated strain CMS), Citrobacter freundii, Escherichia coli, E. fergusonii, Bifidobacterium animals, and Propionibacterium acidipropionici. Results indicated that CF cultures can be used as a tool to identify bacteria which are antagonistic to S. typhimurium in the chick cecum.

Two-Step Mucosal Competitive Exclusion Flora Treatment to Diminish Salmonellae in Commercial Broiler Chickens

There is a need to control the intestinal colonization of broiler chickens by salmonellae in order to reduce the contamination of poultry products. A two-step treatment of broiler chicks with a mucosal competitive exclusion culture (MCE) was tested, in which the MCE was first sprayed on chicks in the hatchery followed by administration in the first drinking water. Three commercial flocks were treated and compared with parallel, untreated control flocks. Customary husbandry practices were employed. Environmental, hatchery, skin with feathers, and cecal samples were analyzed at 3 and 7 wk for the presence of salmonellae. Carcass rinse samples of fully processed birds were analyzed similarly. The results indicated that initial feed, water, and litter contamination was at a low frequency (< 10%). Eggshell fragments and chick paper pads were frequently contaminated (> 50%). After 3 wk growth, contamination of litter, skin with feathers, and ceca were significantly (P < .05) reduced in treated flocks as compared with control flocks. Salmonellae prevalence in ceca and in processed carcass rinses was also significantly (P < .05) reduced from 41% in control flocks to 10% in treated flocks. The study showed that treatment of chickens in a commercial setting with MCE cultures can serve as a useful means to reduce salmonellae contamination.

Colonization of broiler chickens by waterborne Campylobacter jejuni.

Chickens on a broiler farm in southern England were found to be colonized with Campylobacter jejuni of a single serotype, Lior 1 Penner 4. The farm was the sole supplier of a local slaughterhouse associated with a campylobacter outbreak in 1984 caused by this serotype. The serotype persisted on the farm for at least 18 months after the outbreak; its prevalence in the human population served by the farm remained high until it disappeared from the farm in 1986. The possible sources and routes of transmission of C. jejuni to the broilers on the farm were investigated. The results showed that vertical transmission, feed, litter, small mammals, and environmental or airborne cross-contamination between sheds or successive crops could be excluded as persistent sources of C. jejuni. The predominant source of C. jejuni on the farm was shown to be the water supply. Direct microscopy and fluorescent antibody methods revealed presumptive campylobacters throughout the farm's water system. Campylobacter-free chickens raised in an animal house and given water from the farm supply became colonized with the serotype of C. jejuni endemic on the farm (Lior 1 Penner 4). An intervention program based on water chlorination, shed drinking system cleaning and disinfection, and withdrawal of furazolidone from feed reduced the proportion of birds colonized with campylobacter from 81 to 7% and was associated with a 1,000- to 10,000-fold reduction in campylobacters recoverable from the carcasses. Two months after the end of the intervention program colonization of the birds returned to high levels (84%), indicating that there was a temporal association between intervention and reduced colonization with C. jejuni. Investigations continue to establish the general applicability of these findings.