Jejuni In Broilers Research Articles

Shedding and Colonization of Campylobacter jejuni in Broilers from Day-of-Hatch to Slaughter Age

Poultry are considered to be the primary reservoirs of Campylobacter jejuni for humans. Campylobacter jejuni can colonize the poultry intestinal tract and its subsequent shedding can result in environmental contamination, resulting in an increased risk of infection for the rest of the flock. At present, there is no information on the daily shedding pattern of C. jejuni in broiler chickens. Thus, the purpose of this study was to determine the daily shedding pattern of C. jejuni in broiler chickens and to correlate intestinal colonization with fecal shedding, which would aid in the development of intervention strategies such as the use of competitive exclusion products at 1 day of age. Twenty-four broiler chicks were orally inoculated with 1.6 x 10(7) colony-forming units of C. jejuni, and the reisolation rate of the organism was determined daily from day 1 to day 43. Fifty percent and 70% of the chicks were shedding C. jejuni within 24 and 48 hr postinoculation, respectively. The group collectively reached a peak excretion on days 13-19 postinoculation. There was a steady decline in fecal shedding after the third week. By market age, on day 43, only 37.5% (9/24) of the birds were shedding C. jejuni in their feces. Throughout the sampling period from days 1 to 43, a cyclic pattern of shedding was observed in individual birds. Individual birds excreted C. jejuni on an average of 25 out of 43 days. The C. jejuni isolate failed to colonize 16.6% (4/24) of the birds. A small percentage of the birds, 12.5% (3/24), were observed to be chronic shedders. Enumeration of C. jejuni in the crop, jejunum, and cecum on day 43 revealed that the cecum was the major colonization site, and 15 out of the 24 birds carried C. jejuni in their intestinal tract.

Evaluation of an Avian-Specific Probiotic to Reduce the Colonization and Shedding of Campylobacter jejuni in Broilers

Campylobacter jejuni has often been responsible for human gastroenteritis. Poultry have often been implicated as a source for these human infections. Intestinal colonization of C. jejuni in the chicken plays a role in carcass contamination during slaughter. Thus, reducing C. jejuni colonization in chickens can potentially reduce the incidence of C. jejuni infections in humans. The use of probiotics to competitively exclude the colonization of intestinal pathogens has been proposed for poultry. Hence, the purpose of this study was to evaluate the use of an avian-specific probiotic containing Lactobacillus acidophilus and Streptococcus faecium for reducing the shedding and colonization of C. jejuni in the chicken intestinal tract. Day-old chicks were randomly allocated into either a probiotic-treated group or a control group. The treated group was given probiotic from day 1 to day 3, and the control group was not given any probiotic. Six hours after the first oral administration of probiotics (treatment) or double distilled water (control), these chicks were challenged with C. jejuni. The frequency of the C. jejuni shedding was monitored until market age. Intestinal colonization was determined for the two experimental groups at slaughter. Results indicated that chickens given probiotics from day 1 to day 3 had a 70% reduction in the frequency of C. jejuni shedding in colonized chicks (P = 0.0001) and a 27% reduction in jejunal colonization in colonized chicks (P = 0.0001) at slaughter when compared with the control group. Thus, the use of the avian-specific probiotic containing L. acidophilus and S. faecium can reduce the colonization and frequency of fecal shedding of C. jejuni in market-aged broilers.

Microbial ecology of Campylobacter jejuni in a United Kingdom chicken supply chain: intermittent common source, vertical transmission, and amplification by flock propagation.

A study of Campylobacter jejuni on a broiler chicken farm between 1989 and 1994 gave an estimated isolation rate of 27% (3,304 of 12,233) from a 0.9% sample of 1.44 million broiler chickens from six to eight sheds over 32 consecutive rearing flocks comprising 251 broiler shed flocks. During the study, C. jejuni was found in 35.5% of the 251 shed flocks but only 9.2% (23 of 251) had Campylobacter isolates in successive flocks, with 9 of those 23 sheds having the same serotype between consecutive flocks, indicating a low level of transmission between flocks. Analysis of a systematic sample of 484 of 3,304 (14.6%) C. jejuni isolates showed that 85% were of 10 serotype complexes but 58% were of 3 serotype complexes, indicating a high degree of strain similarity throughout the entire study. The three commonest types were detected in 8 of 32 flocks during the 5-year study period, suggesting an intermittent common external Campylobacter source. This hypothesis was tested by a retrospective cohort analysis of C. jejuni rates and types by reference to hatchery supplier of the 1-day-old chicks. Isolation rates of C. jejuni and frequency distribution of types were determined in 6-week-old broiler chickens identified by the hatchery supplying the original chicks. The isolation rate of C. jejuni in broilers, supplied by hatchery A, was 17.6%, compared to 42.9% (P < 0.0001) for broilers reared from chicks supplied by hatchery B. In two instances, when both hatcheries were used to stock the same farm flock, Campylobacter isolates were found only in those sheds with chicks supplied by hatchery B. Thus, the frequency distribution of Campylobacter types for chickens supplied by the two hatcheries over the 5-year period showed marked dissimilarity. These findings suggest that the isolation rate and type of Campylobacter isolates in broiler chickens was associated with the hatchery supplying chicks. The lack of diversity of types and the intermittent high positivity of sheds is evidence for a common source of C. jejuni introduced by vertical transmission rather than contamination at the hatchery or during transportation.

Campylobacter jejuni in broilers: the role of vertical transmission.

The role of broiler eggs in the transmission of Campylobacter jejuni to broiler grow-out flocks was investigated. Six breeder flocks supplying broiler eggs to hatcheries were examined for cloacal carriage of C. jejuni. Of 240 birds tested, 178 (74%) were C. jejuni-positive. Eggs from these birds examined for C. jejuni penetration of the egg shell indicated that 185 of 187 were campylobacter-free. Eggs from breeder flocks of unknown C. jejuni status were also examined for C. jejuni shell penetration. C. jejuni was not isolated from 142 eggs examined. A further 193 hatchery eggs incubated and hatched in the laboratory were campylobacter-free. Six farms containing the progeny of C. jejuni-positive breeder flocks were monitored. Eight hundred and forty birds from 14 flocks in these grow-out farms were campylobacter-free during their 6-week grow-out period. Experimental egg-penetration studies indicated that C. jejuni transmission via the egg is not easily effected. Of 257 eggs surface-challenged with C. jejuni, 162 hatched; all were campylobacter-free. Of 167 eggs injected with C. jejuni, 12 hatched; 2 of these were colonized with C. jejuni. Our data do not support a role for vertical transmission of C. jejuni in commercial broiler production.