Colonization Of Poultry Research Articles

Aspects of epidemiology of campylobacter in poultry

Summary Campylobacter bacteria, which in humans cause infections with severe symptoms of diarrhoea, are mainly transmitted by food, especially poultry meat products. Several studies on Campylobacter colonization in breeders, laying hens, and broilers were carried out. Isolates were serotyped, using a modification of the Penner system, in order to identify epidemiological factors contributing to the Campylobacter colonization of poultry. No evidence was found for vertical transmission from breeder flocks via the hatchery to progeny, nor for horizontal transmission from one broiler flock to the next via persistent contamination of the broiler house. The major route for Campylobacter colonization of poultry is horizontal transmission from the environment. Pigs and poultry flocks (broilers, laying hens, and breeders), and to a lesser extent sheep and cattle, were found to be potential sources of Campylobacter contamination. Horizontal intervention procedures at the farm level have to be studied further to evaluate the effectiveness of strict hygienic practices during the whole production period. Screening for antibiotic resistance revealed 181 out of 617 Campylobacter isolates (29%), originating from a large number of broiler flocks, to be quinolone resistant. Quinolone treatment of Campylobacter colonized broiler chicks was found to induce quinolone resistance under experimental conditions. Therefore, quinolone treatment should not be seen as an answer to the problem of Campylobacter colonization in poultry flocks.

The influence of diet on the mucin carbohydrates in the chick intestinal tract.

The presence of nutrients in the intestinal lumen is a major factor influencing bacterial colonization in poultry. This study was conducted to investigate the effects of poultry feed on viscosity of intestinal contents and on mucin carbohydrates by comparing jejunal supernatants and the histochemical composition of goblet cells in chicks reared to 5 weeks of age on either a conventional maize-based diet or a wheat-based diet or a wheat diet supplemented with 0.1% xylanase. Regional differences in the distribution of the neutral, carboxylated and sulphated mucins were demonstrated using conventional histochemical techniques, while a panel of lectins was used to study alterations in glycoconjugate synthesis of mucins in chicks fed different diets. 1) Feeding a diet supplemented with xylanase lowered the viscosity but increased the amount of neutral, carboxylated and sulphated mucins in the jejunum. 2) In chicks fed a maize-based diet, neutral mucins increased in the surface and upper crypt goblet cells of the small and large intestines but decreased in the caecum. 3) Feeding a diet supplemented with xylanase modified crypt-surface glycosylation of N-acetylglucosamine residues and resulted in loss of sialic acid residues in the small and large intestines. These results indicate that the constituents of poultry feed, in particular the consumption of a diet supplemented with xylanase, lead to changes in intestinal viscosity and mucin composition which are associated with alterations in the goblet cell glycoconjugates of the chick intestinal tract.

Sensitivity of Australian isolates of Salmonella enteritidis to nitrofurantoin and furazolidone

Susceptibility of 66 and 62 Australian isolates of Salmonella enteritidis to nitrofurantoin and furazolidone, respectively, was determined. Most isolates were susceptible to both antibiotics. Cross-resistance was low among all isolates, but higher among the subset of phage type 4 isolates. These results contrast directly with those of a previous study (Rampling, A., Upson, R. and Brown, D.F.J. (1990) J. Antimicrob. Chemother., 25: 285–290). Sensitivity among Australian isolates of S. enteritidis does to some extent, support the contention that furans may have played a role in the selection and enhanced colonisation of poultry by Salmonella enteritidis in Britain. Furthermore, nitrofurantoin should not be used as a selective agent in the isolation of Salmonella enteritidis.

Salmonella enteritidis: Virulence factors and invasive infection in poultry

Worldwide, Salmonella enteritidis is a clinically prevalent Salmonella serotype, which is associated with the consumption of foods containing eggs or poultry meat from systemically infected chickens. Several factors, including lipopolysaccharide structure, plasmid carriage and the expression of fimbriae, have been investigated in relation to their roles in pathogenicity. While each of these factors has been linked to virulence in different hosts, most have been discounted as playing a part in the systemic colonization of poultry. It is possible that recent acquisition of virulence factors, in combination with existing mechanisms, has contributed to the development of systemic infection with S. enteritidis and its consequent prevalence in poultry. The expression of certain fimbrial structures appears to be linked most strongly with systemic colonization in chickens, although the expression of other factors is necessary for infection.

The significance ofcampylobacter jejuniinfection in poultry: A review

Campylobacter is a significant cause of enterocolitis in consumers of undercooked poultry meat. Campylobacter jejuni is the most significant of the three thermophilic Campylobacter species, and is responsible for intestinal colonization in poultry and food-borne enteritis in humans. Generally, C. jejuni is apathogenic in poultry, although newly hatched chicks and turkeys may develop a transient diarrhoea following infection. Modern intensive poultry production favours the introduction of infection into commercial growing units, resulting in intestinal colonization during the second to fourth weeks inclusive. Routes of infection include contaminated fomites, infected water supply, rodents, insects, and free-living birds. Vertical transmission is considered unlikely. Contamination of poultry meat is enhanced by deficiencies in transport and processing of broilers and turkeys. Scalding, defeathering and evisceration represent the significant points of cross-contamination during processing. Epidemiological correlation has been established between consumption of contaminated chicken and outbreaks of human campylobacteriosis. Amelioration of infection by application of improved standards of hygiene and decontamination is possible in the context of commercial poultry production. Improvement in washing of carcasses, and the application of chemical disinfectants and gamma irradiation have the potential to reduce the prevalence of C. jejuni contamination in poultry meat. These innovations, together with improved storage and handling of meat products, will reduce the risk of campylobacteriosis to consumers.

Control of Salmonella enteritidis infections in poultry by polymyxin B and trimethoprim

Antimicrobial compounds were screened in vitro in Trypticase soy broth for antimicrobial activity against a virulent strain of Salmonella enteritidis. Of the several compounds tested, polymyxin B showed the strongest inhibition in vitro, preventing growth at a concentration of less than or equal to 10 micrograms/ml. Polymyxin B administered in the drinking water was effective in vivo for preventing infections in 1-day-old chickens but did not remove established infections in 1-week-old chickens. It was found that trimethoprim, which was not active in vitro, prevented colonization and removed existing infections in 1-day-old chickens when it was administered together with polymyxin B sulfate. Enrichment cultures in which selenite-cystine and tetrathionate broth media were used showed that chickens given a combination of 100 micrograms of polymyxin B sulfate per ml and 250 micrograms of trimethoprim per ml 24 h prior to oral inoculation with 10(8) to 10(9) CFU were negative for S. enteritidis after 7 days. Established infections (10(5) to 10(6) CFU/g of feces) in 1-week-old chickens were eliminated by treatment with the polymyxin-trimethoprim system. This antimicrobial agent treatment may be useful for preventing colonization in poultry and for eliminating S. enteritidis from infected flocks.

Research Note: Presence and Impact of Salmonella Contamination in Commercial Broiler Hatcheries

Egg fragments from hatching trays, swabs of belting material, and paper pads from three broiler hatcheries were sampled for the presence and level of salmonellae. Salmonella serotypes were recovered from 71, 80, and 74% of the egg fragments, belting material, and paper pads, respectively. Overall, salmonellae were found in 75, 91, and 67% of the samples taken at Hatchery 1, 2, and 3, respectively. Thirty-eight of 40 randomly selected samples contained greater than 103 salmonellae cells per sample. All of the Salmonella serotypes encountered in the present study had previously been isolated from poultry. The presence and persistence of salmonellae contamination in the hatchery suggests that the vulnerable day-of-hatch chick may be at a greater colonization risk in the hatchery than during grow-out. Contamination and penetration of the shell of hatching eggs may constitute the most important link (or critical control point) in the transmission of salmonellae to young birds and eventually the consumer. An effective intervention method may have to be employed at this point to break the transmission link and significantly impact the overall problem of Salmonella colonization in poultry.

Potentials for Colonization Control of Campylobacter jejuni in the Chicken

Campylobacter jejuni is a major cause of enteritis in humans. Chicken is the most important vehicle in transmitting the agent to humans in the United States. The organism colonizes the intestinal tract of the chicken and there enters into a non-pathologic, commensal relation. During slaughter and processing the organism can, and does, adulterate the product. Unsuccessful attempts have been made to “clean” the contaminated carcasses or provide pathogen free flocks and rearing facilities. Therefore, the approach to intervene and diminish C. jejuni in the intestinal tract is now being studied. We have been gathering background data on colonization dose, isolate differences regarding colonization, competitive exclusion, expression of outer membrane proteins by the organism, immune response of the chicken to colonization, antibody neutralization of colonization, and how poultry lineage influences susceptibility to colonization. By using this information we hope to diminish colonization of poultry with C. jejuni.

Integrated Colonization Control of Salmonella in Poultry

Control of the human enteropathogen Salmonella in poultry is a top priority of the USDA and the Agricultural Research Service. Numerous approaches are being taken to try and eliminate or at least reduce the levels of Salmonella on processed broilers. In this paper, factors that affect the degree of Salmonella colonization of poultry are examined, and different approaches to reduce Salmonella colonization are discussed. When used together, these approaches form a concept called integrated colonization control.

Origin and Prevalence of Campylobacter jejuni in Ducks and Duck Meat at the Farm and Processing Plant Level

The epidemiology of Campylobacter jejuni colonization in poultry at the farm remains unclear. In this study, over a 6-month period, we evaluated the prevalence and possible ways of transmission of C. jejuni in a duck farm and a processing plant, belonging to the same company. C. jejuni was isolated from fecal ducking samples as early as the 4th day of age while the birds were still on wire. Practically all the birds became positive after the 11th day of age. Based on egg and fecal duckling sample analysis and feeding and water trials with farm and university feed and water, colonization of the birds by C. jejuni did not originate from the hatchery. Central feed and water was not a source of colonization for the ducklings. Wild birds and flies were also excluded as a source because their entrance to the houses was improbable during the first 5 days. Ducklings placed in sterile university brooders, located inside the farm brooder houses away from the other birds and given university feed and water were colonized by the 6th and 7th day. The most probable source of colonization by C. jejuni was the C. jejuni carrier rats and mice found in abundance on the premises. The prevalence of C. jejuni in rat fecal contents was 86.7%, and rat and mice droppings were found in the feeding and watering troughs. In the processing plant, C. jejuni was isolated from 96.7% of feather picker drip water samples. Isolation rates of C. jejuni for the liver, gizzard, heart, and skin samples were 34, 20, 6 and 6.7%, respectively, which are considerably lower than the rates reported for the chickens and turkeys. These lower rates were probably due to passage of the carcasses through two tanks of hot wax after defeathering.