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1.
Cultural monitoring was used to determine the incidence and sources of salmonellae in a 4160-bird broiler flock raised on litter in 32 pens. Twenty-five of the pens remained apparently free of salmonellae during the 49-day growing period. Salmonella johannesburg, first detected in the meat meal component of the starter ration, was recovered from the litter of seven pens and from the intestines of dead or culled chicks from two pens. Salmonella alachua was also recovered from two of these pens. Culture of swabs collected from the plastic crates used to transport this flock for processing showed that 97/112 (86.6%) were contaminated with salmonellae (15 serovars) before the birds were loaded. The crate washer at the plant did not remove salmonellae from these crates: 97/132 (73.5%) crates sampled after washing yielded salmonellae. Eleven serovar were recovered, including S. johannesburg and S. alachua introduced by the infected flock. Twelve of 31 chickens (38.7%) collected when the birds were unloaded at the processing plant were intestinal carriers of S. johannesburg and/or S. alachua and 29 (93.5%) were external carriers. Salmonella johannesburg, S. alachua and four other serovars were isolated from the feathers of these birds. Eleven of 25 (44%) carcasses tested from this flock yielded salmonellae. Salmonella johannesburg or S. alachua, first isolated from the infected flock, were recovered from five carcasses and S. haardt and S. Typhimurium, first isolated from the transport crates were recovered from six carcasses.  相似文献   

2.
Cultural monitoring was used to study the incidence and sources of salmonellae in a 4160 bird broiler flock during the growing period, transport and processing in a commercial plant. No salmonellae were isolated from any of 132 litter samples of 189 chickens cultured during the seven-week growing period, even though nest litter samples from four of the eight parent flocks yielded salmonellae and Salmonella worthington was isolated from the meat meal component of the grower ration. On arrival at the plant, 2/23 birds sampled carried S. infantis on their feathers, although intestinal cultures failed to yield salmonellae. Three of 18 processed carcasses samples yielded salmonellae (S. infantis, S. heidelberg, S. typhimurium var copenhagen). The most likely source of these salmonellae was the plastic transport crates, since 15/107 sampled before the birds were loaded yielded salmonellae (S. infantis, S. typhimurium). The crate washer at the plant did not reduce the incidence of Salmonella-contaminated crates, since 16/116 sampled after washing yielded salmonellae (S. infantis, S. typhimurium, S. heidelberg, S. schwarzengrund, S. albany).  相似文献   

3.
Rinse fluids collected from eight different lots of commercially processed broiler carcasses were cultured for salmonellae by a meat probable number method. Most probable number values of 80 or less were obtained from all carcasses in three of the eight lots, but two lots contained carcasses which yielded more than 1000 salmonellae. Similar numbers of salmonellae were recovered in repeated rinses of the same carcasses, suggesting that only a small proportion of the total population was recovered in each rinse. Five lots originated from flocks of known Salmonella status. More salmonella were recovered from carcasses which originated from flocks infected in the first week of life than from flocks infected at a later date. Carcasses from a flock which was processed immediately after a contaminated flock yielded more salmonellae than carcasses processed at the beginning of the day in a clean plant.  相似文献   

4.
Market-age broiler chickens from flocks infected with Salmonella typhimurium were killed after being placed in crates and subjected to simulated shipping conditions for five, 19 or 24 hours. The cloacal feces, ceca and exteriors of the birds were cultured for salmonellae to identify shedders, cecal carriers and external carriers respectively, and the results compared with those obtained from pen-mates killed at the time the tested birds were put into the crates. Carriage of S. typhimurium was significantly higher among birds placed in clean crates than among the uncrated controls, mainly due to an increase in cecal carriers (from 23.5% to 61.5%). This increase was not related to the time spent in the crate. Twenty-four chickens were placed in crates contaminated with Salmonella alachua and all 24 became carriers of this organism: 22 (91.5%) of these were cecal carriers and 18 (75%) were shedders. This contamination also spread to 15/24 chickens placed in clean crates and "shipped" in the same truck: six of these became cecal carriers and seven were shedders. These results indicated that chickens in shipping crates which are exposed to salmonellae under transport conditions may readily become infected and begin to shed salmonellae within 24 hours.  相似文献   

5.
The incidence of Salmonella contamination in ten Saskatchewan broiler flocks varying in size from 6 200 to 14 000 was investigated from February, 1977 to April, 1979. Prior to the initial chick placement, brooding equipment, feed, water and fresh litter samples were found to be free of Salmonellae. Samples obtained from the clean and disinfected processing plant equipment before the commencement of daily operation were negative except the isolation for Salmonella anatum from the fingers of the defeathering machine in flock 4. There was no evidence of Salmonella contamination in flocks 5, 6, 8 and 10. The incidence of Salmonella was lower when cloacal swabs were taken from day old chicks fasted for 48 hours than for the same groups of chicks when carcasses were blended in nutrient broth (flocks 7 and 9). The blending of such chicks appears to be a more critical test. The serotypes isolated from eviscerated birds were the same as those isolated from used litter samples. Salmonella saintpaul was isolated from a water sample at 53 days in flock 1 and the same serotype was recovered from the intestinal contents and skin of eviscerated birds. Salmonella typhimurium was recovered from the eviscerated birds and neck samples in flock 3. In flock 4, S. saintpaul and S. anatum were isolated from 13% of the eviscerated birds sampled. Salmonella thompson, Salmonella agona and Salmonella heidelberg were recovered from 61%, 5% and 1%, respectively, of the processed carcasses sampled in flock 7.  相似文献   

6.
The contamination of poultry in the Netherlands with Salmonella enteritidis was tested. For this, different methods (detection of S. enteritidis in faecal samples of 25 g; detection of S. enteritidis in cloacal swabs; detection of S. enteritidis by serological testing of antibodies in serum) were compared for their efficiency to detect S. enteritidis in flocks of poultry. Testing of faecal samples clearly yielded the best results. This method was used in a transmission study, in which 14 flocks descending from a contaminated primary mother flock were screened for the presence of S. enteritidis. The method was also used for screening 49 flocks of laying hens and 52 flocks of broiler chickens throughout the Netherlands. From the transmission study it became clear that S. enteritidis, phage type 2 (Dutch phage set) was isolated both from the mother flock and from five of the descendent flocks. Screening of poultry flocks for the presence of salmonella revealed that salmonella was present in 47% of the layer flocks and in 94% of the broiler flocks. S. enteritidis was isolated from 15% of the flocks screened.  相似文献   

7.
A nation-wide survey was carried out in 370 randomly chosen French commercial broiler chicken flocks from October 2005 to September 2006 to determine Salmonella spp. prevalence and to identify risk factors for contamination, at the end of the rearing period. The Salmonella status of the flocks was assessed from five faecal samples (litter swabs) analysed by classical bacteriological methods. A flock with at least one contaminated sample was classified as a Salmonella-positive flock. The apparent prevalence of Salmonella was 8.6% (95% CI: 5.7, 11.5%). The most prevalent serovar was S. hadar followed by S. anatum and S. mbandaka. Logistic regression methods were used to analyse the associations between husbandry practices, farm characteristics, general hygiene and the Salmonella status of the sample. The risk for Salmonella contamination of the flock at the end of the rearing period increased when neighbours helped in the placement of day-old chicks. On the contrary, the risk decreased when mobile equipment was dismantled before cleaning and disinfection, when the farm had a specific container for dead-bird disposal and when acetic acid was added to the drinking water.  相似文献   

8.
The withdrawal of feed from the pens of broiler chickens for several hours before they are shipped for slaughter is an increasingly common practice, whose objective is to decrease fecal contamination of birds during processing. In this study, Salmonella typhimurium-infected market age broiler chickens were subjected to feed withdrawal for eight hours, then placed in crates for 18 hours before they were killed and weighed. The intestines, ceca, and cloacal feces were weighed and cultured for salmonellae. The feces deposited in the crates were also weighed and cultured. The results were compared with those of control birds whose feed was not withdrawn before they were placed in crates. The withdrawal of feed did not significantly affect the total liver weights of the birds, but reduced the weights of the intestines in 7/10 groups, and of the ceca in 5/11 groups, and dramatically reduced the amount of feces deposited in the crates. There was no consistent effect on excretion of salmonellae. These results indicated that feed withdrawal for eight hours before broilers are shipped for slaughter should be effective in reducing the spread of fecal contamination and of salmonellae during transport and processing, and in improving the effectiveness of crate washing procedures.  相似文献   

9.
We built a decision-support system to assess the risk of contamination of chicken-broiler flocks by Salmonella at the end of the rearing period. This system was developed from the survey data from 85 chicken-broiler flocks located in western France. First, we estimated the probability of contamination of the house by Salmonella before placement of day-old chicks via a cleansing inspection using a visual-inspection grid, a decontamination evaluation using count-plates, and risk factors for Salmonella persistence in the barn after cleansing and disinfection. Second, we estimated (using a logistic model) the probability of prevalent contamination of the flock by Salmonella at the end of the rearing period. Validation was carried out on 60 flocks selected from seven production companies in western France. The risk estimated by the model was compared to the Salmonella status of the flock (gold standard) assessed by samples taken from the environment of the broilers and analysed with classical bacteriological methods. The sensitivity was 97.8% and the specificity 64.3%.  相似文献   

10.
In 40 cases salmonellae of the serovar Salmonella (S.) gallinarum were culturally isolated from domesticated gallinaceous birds submitted for diagnostic purposes in the period of 1979-1989. On the basis of the cultural and biochemical features found 35 of them could be assigned to the biovar Pullorum and 5 to the biovar Gallinarum. Of 35 isolates of the biovar Pullorum, 29 were isolated from pure bred chickens of small fancy-exhibition type flocks, 4 from floor-housed adult brown hybrid laying hens and one each from broiler chicks and pheasant chicks (Phasianus colchicus). Acute to subacute courses of the pullorum disease were observed in the 4 flocks of brown hybrid hens. Of 5 isolates of the biovar Gallinarum, 4 were isolated from adult brown hybrid laying hens kept in battery cages and one from floor-housed brown hybrid pullets of the laying type. First cases of fowl typhoid occurred early in the summer of 1988. The disease was characterized by a peracute course in the 4 flocks of brown laying hens and by a more acute course in the pullet flock. The primary source of the fowl typhoid producing organisms was not elucidated.  相似文献   

11.
Sources of Salmonellae in broiler chickens in Ontario.   总被引：3，自引：2，他引：1       下载免费PDF全文
Sources of Salmonellae infecting broiler chicken flocks in Ontario were investigated from July, 1975 to April, 1976. Three broiler flocks were investigated on each of four farms which received chicks from a common hatchery. Samples of feed and new litter were preenriched in nonselective broth subcultured to Salmonella-selective enrichment broth and plated on Salmonella-selective differential agar.Samples of used litter, water, culled chicks, insects, mice, wild birds and environmental swabs were not cultured initially in the nonselective broth. Fecal samples from principal and occasional flock attendants were examined for Samonellae. Salmonella infection, as judged by contaminated flock litter was detected in six flocks on two of the farms while the flocks on the other farms remained negative. Salmonellae were isolated from 23 of 412 feed samples (nine serotypes), six of 35 new wood shaving samples (four serotypes), one of 29 pools of culled chick viscera (one serotype) and 44 of 267 used litter samples (14 serotypes). These results indicate that broiler chicken flocks were infected with diverse Salmonellae introduced in day old chicks, pelleted feeds, wood shavings and residual contamination from the preceding flock.  相似文献   

12.
Screening of broiler flocks for their Campylobacter carriage on farm level and consequently the spread of Campylobacter spp. during slaughtering can help to identify hygiene control points. Therefore, between December 2001 and August 2002 in total 51 broiler flocks from three farms of different geographical regions in Germany were analysed for thermophilic Campylobacter. Campylobacter spp. were isolated from 45% of the broiler flocks examined. Subsequently, 1101 samples were taken from 22 flocks during different stages of processing. Samples were collected from: transport crates before and after cleaning/disinfection, evisceration, post-scalded and post-chilled carcasses and endproducts. Additionally, 45 selected Campylobacter isolates of droppings were genotyped by pulsed-field gel electrophoresis (PFGE). Campylobacter carriage of flocks showed seasonal variation, with the highest contamination rate during the period of June to August. No evidence was found for a horizontal transmission from one broiler flock to the next via a persistent house-contamination. In each positive flock, one to three different genotypes were found. One or two clones dominated isolations obtained from the farm level. The fact that in different flocks indistinguishable isolates of clonal origin were detected during the same rearing period suggested a transmission between the broiler flocks or an intermittent common external source. In one case, isolates of clonal origin were detected in various farms during different rearing periods. Sampling during processing confirmed that the entrance of a positive flock resulted in contamination of the abattoir environment. Campylobacter spp. were isolated from all sampling stages along the processing line, with a percentage of 91.1-100 of isolates at different stages of slaughtering.  相似文献   

13.
Contaminated poultry meat has been identified as one of the principal foodborne sources of Salmonella. The development of rapid detection assays for Salmonella would enable official agencies and food industries to identify contaminated foodstuffs in a more timely manner. In addition, these diagnostic tools could allow more 'real time' decisions to be made regarding end product acceptability. In this study, a survey was carried out to determine the prevalence of Salmonella in raw broiler carcasses. A total of 198 neck skin samples were obtained from within 40 flocks at a commercial broiler slaughtering facility. The presence of Salmonella was assessed by traditional culture methods and by a Salmonella-specific polymerase chain reaction (PCR) test. Salmonella was recovered from 32 (16%) of all samples using traditional culture methods. In contrast, the PCR assay proved to be more sensitive and detected Salmonella DNA in 38 (19%) of the samples tested. The pathogen was detected in 45 (23%) of the 198 samples when culture and PCR results were combined. The sensitivity of the PCR test was also greater than culture when detecting Salmonella from within flocks (53% of flocks by PCR, 30% of flocks by culture). The combination of both tests revealed that 55% of the flocks were contaminated with Salmonella. The PCR assay proved to be a highly specific and sensitive method for detecting Salmonella and the incorporation of a routine PCR test in conjunction with standard culture could be effective in providing a more accurate profile of the prevalence of this pathogen in broiler carcasses.  相似文献   

14.
Broiler-chicken are often Salmonella carriers. However, these bacteria are responsible for major food-borne human infection, in which poultry-meat products are frequently implicated. In order to prevent Salmonella spread during the slaughtering process, control measures should be implemented at the farm level to reduce the prevalence before slaughtering. The objective of this study was to identify the risk factors for Salmonella contamination in French commercial broiler flocks at the end of the rearing period. A prospective study was carried out in 1996 and 1997 on 86 broiler flocks located in western France. The Salmonella status of the flocks was assessed by means of litter swabs and dust samples analyzed with classical bacteriological methods. Sixty flocks (70%) had at least one contaminated environmental sample and were classified as Salmonella-contaminated flocks. Logistic regression was used to assess association of managerial practices, general hygiene and results of environmental Salmonella recovery, with the odds that the flock itself would be Salmonella-contaminated at the end of the rearing period. Salmonella contamination of the house before placing day-old chicks and the Salmonella contamination of day-old chicks were significantly related to Salmonella contamination of the flock at the end of the rearing period. The risk for Salmonella contamination of the flock was increased when feed trucks parked near the entrance of the change room and when feed meal, instead of small pellets, was provided at the start.  相似文献   

15.
Campylobacter is recognized as one of the leading cause of gastroenteritis worldwide, and is frequently isolated from the small intestines and ceca microflora of chickens. Twenty-one out of 81 Campylobacter-positive poultry flocks were selected to evaluate the genetic diversity of Campylobacter isolates and to study the distribution of genotypes among flocks. Campylobacter isolates recovered from chicken carcasses and ceca were analyzed by pulsed-field gel electrophoresis (PFGE). Little diversity was found among Campylobacter strains isolated from a given carcass, with a maximum of 2 different genotypes being present. However, at flock level, as many as 4 different profiles were observed. Typing of strains showed that most strains isolated from ceca were similar to those isolated from corresponding broiler carcasses. A total of 39 different macrorestriction profiles were observed, with evidence of Campylobacter cross-contamination among broiler flocks in Quebec slaughterhouses. Surprisingly, some flocks shared related genotypes both with and without sharing similar rearing practices. Existence of such cross-contamination must be considered to in developing strategies to control Campylobacter in chickens, and to avoid bacteria contamination of noncolonized flocks. Further typing studies of Campylobacter found in hatcheries, farm environment, and crates or trucks in Quebec might be helpful in elucidating the kinetics of broiler chicken Campylobacter contamination.  相似文献   

16.
Of 345 market chicken carcasses received directly from selected processing plants across Canada, six yielded salmonellae. One of the plants submitted 122 carcasses none of which yielded these organisms. A second plant had one Salmonella-contaminated carcass among 20 which were examined. Each of these two plants was subected to detailed bacteriological examinations on four occasions.

In these detailed examinations a total of 175 samples or specimens for culture were taken from a variety of surfaces including vent areas of carcasses, operators' hands, equipment surfaces and from water in tanks of iced birds. Twenty-five (14 per cent) of the cultures yielded salmonellae and all but one of these were either S. oranienburg or S. infantis. Isolations were made during five of the eight series of examinations. The evidence indicated that Salmonella-infected flocks were frequently slaughtered and that Salmonella contamination could become widespread in the plant during processing. The organisms are apparently eliminated from all but a small percentage of the carcasses during processing but opportunities exist for recontamination during subsequent handling.

  相似文献   

17.
Prevention of Salmonella contamination of poultry products requires detailed knowledge of the main sources associated with its presence in the production system. The aims of this study were to determine the main sources of Salmonella contamination in broiler production during growing, to assess the risk factors for Salmonella contamination at the end of the rearing period and to determine the main serovars involved in broiler production systems in Eastern Spain. A total of 65 different broiler houses from different farms were sampled. Each house was sampled at different times during the rearing period. First, when the previous flock was taken to the slaughterhouse, samples of dust, surfaces and previous flock faeces were collected. After cleaning and disinfection (C&D), samples of dust and surfaces were also taken. On the first day of rearing, samples of water, bedding, farming boots, meconiums, delivery-box liners and feed were collected. During rearing, feed samples were taken directly from the truck and from feeders. On slaughter day, samples of dust, surfaces, water, feed and faeces were also collected. Finally, two days after slaughter, carriers (rodents, flies and beetles) were trapped. All samples collected were analysed according to ISO 6579:2002 (Annex D) and positive samples were serotyped in accordance with Kauffman-White-Le-Minor technique. Our results showed that all different types of samples collected were contaminated with Salmonella (prevalence ranged between 1.5% and 38.6%). The most contaminated samples related with poultry production were: delivery-box liners (32.0%), faeces samples (31.2%), dust samples (25.0%), farming boots (19.7%) and feed from feeders (16.0%). However, the most important risk factors for Salmonella contamination of the flocks at the end of the rearing period were Salmonella status of the house after cleaning and disinfection, Salmonella status of day-old chick flocks and feed from feeders. Twenty-one different serovars were isolated from the samples analysed. The most prevalent were in decreasing order: Salmonella Enteritidis (52.9%), S. Hadar (17.8%), S. Virchow (8.9%) and S. Ohio (5.4%). The study suggested that there are many sources for Salmonella contamination and persistence in broiler production. Hence, the whole production chain needs to be controlled to eradicate the bacteria from primary production.  相似文献   

18.
Broiler chickens are often intestinal carriers of Campylobacter. During processing, Campylobacter may be spread over the carcass. Thus, undercooked chicken meat, or other foods contaminated by raw chicken can act as a source of infection to humans. This study was conducted to identify risk factors for chicken flocks being colonized with Campylobacter. Eighteen chicken farms with altogether 62 chicken compartments were studied for 1 year with visits during each growing period and sampling of chicken caecal contents at slaughter. Four to six subsequent flocks were raised in each compartment during the study. A detailed questionnaire was used to record farm parameters such as building materials, feed and water equipment, hygiene and management routines. Campylobacter prevalence varied between farms, between growing periods within the farms and also during the year, with lowest prevalence during the spring. Campylobacters were isolated from 27% out of 287 flocks. Only two farms were negative at all samplings. Often the flock following a positive flock in a compartment was negative, indicating that normal cleaning and disinfecting routines are sufficient for eliminating the bacteria from the house. Usually only one serotype was found in each positive flock. Campylobacter occurrence increased with the age of the chickens at slaughter, and also with flock size.

Univariable chi-square tests were done of the association between possible risk factors and Campylobacter prevalence. Factors associated with higher Campylobacter prevalence in flocks were lack of or diffuse hygiene barriers, increasing flock size, increasing age at slaughter, short vs. long empty periods, wet litter beds, other poultry nearby or staff handling other poultry, flocks divided before slaughter, staff loading to slaughter at several farms and occurrence of mice. Under Swedish conditions, water does not seem to be a source of infection for chickens. Origin and handling of day-old chickens, feed additives, houses and litter were not associated with higher Campylobacter prevalence.  相似文献   


19.
Broiler-chicken are often Salmonella carriers. However, these bacteria are responsible for major food-borne human infection, in which poultry-meat products are frequently implicated. In order to prevent Salmonella spread during the slaughtering process, control measures should be implemented at the farm level to reduce the prevalence before slaughtering. The objective of this study was to identify the risk factors for Salmonella contamination in French commercial broiler flocks at the end of the rearing period. A prospective study was carried out in 1996 and 1997 on 86 broiler flocks located in western France. The Salmonella status of the flocks was assessed by means of litter swabs and dust samples analyzed with classical bacteriological methods. Sixty flocks (70%) had at least one contaminated environmental sample and were classified as Salmonella-contaminated flocks. Logistic regression was used to assess association of managerial practices, general hygiene and results of environmental Salmonella recovery, with the odds that the flock itself would be Salmonella-contaminated at the end of the rearing period. Salmonella contamination of the house before placing day-old chicks and the Salmonella contamination of day-old chicks were significantly related to Salmonella contamination of the flock at the end of the rearing period. The risk for Salmonella contamination of the flock was increased when feed trucks parked near the entrance of the change room and when feed meal, instead of small pellets, was provided at the start.  相似文献   

20.
An integrated broiler company experienced a major outbreak of pullorum disease during 1990. The outbreak resulted in the distribution of Salmonella pullorum-infected birds to more than 150 roaster flocks in five states. Twenty-two parent (multiplier) breeder flocks became infected. An epizootiological investigation uncovered a grandparent male line breeder flock as the index flock supplying males to the affected parent flocks. Transmission apparently occurred vertically through the egg and horizontally by contact in the hatcheries and by placement of chicks on contaminated litter.  相似文献   

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