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1.
The best enrichment broth and DNA extraction scheme was determined for rapid and sensitive detection of Salmonella Enteritidis in steamed pork using real-time PCR. The inhibitory effect of commonly used Salmonella enrichment broths, Rappaport-Vassiliadis (RV) and Muller-Kauffmann tetrathionate with novobiocin (MKTTn), on real-time PCR was confirmed. The inhibition of PCR was statistically significant (p < 0.05) in RV and MKTTn, as compared with buffered peptone water (BPW) or phosphate-buffered saline. The inhibitory effect of the selective enrichment media was successfully removed by using a modified DNA extraction, PrepMan Ultra Reagent with an additional washing step or the DNeasy Tissue Kit. In three experiments, when applied to detection of Salmonella Enteritidis in steamed pork, the real-time PCR coupled with single 24 h enrichment with BPW performed better than double 48 h enrichment with BPW plus RV or MKTTn. The simple real-time PCR assay using BPW proved to be a rapid and sensitive test for detection of low concentrations of Salmonella Enteritidis in steamed pork samples as compared with the conventional culture method.  相似文献   

2.
The present study was conducted to evaluate the sensitivity and specificity of an immunochromatography-based diagnostic kit for Salmonella. The analytical sensitivity of the test when using pure colonies of different Salmonella species was in the range of 1 X 10(4) to 1 x 10(5) colony-forming units per milliliter. The strip detected 19 of 22 strains of Salmonella spp. but failed to detect S. worthington, S. choleraesuis var. kunzendorf and S. johannesburg. The strip did not detect 27 different enteric bacteria, including Escherichia coli O157:H7, Campylobacter jejuni, Shigella sonnei, and Vibrio parahaemolyticus. In direct testing of feces (n = 66) from chickens infected with Salmonella typhimurium, the strip had a sensitivity of 12.3% and a specificity of 100%. Evaluation of the strip assay (n = 510) after sample pre-enrichment in 2% buffered peptone water (BPW) yielded a sensitivity of 93.8% and specificity of 89% when compared to isolation and identification with xylose-lysine-tergitol 4 (XLT4) selective plating media. Subsequent enrichment in Hajna tetrathionate (TT) broth yielded a higher sensitivity (94.7%) and specificity (96.8%). The agreement (kappa) between the strip test and isolation was 0.004 in direct fecal testing, 0.82 in BPW, and 0.89 in TT broth. The assay could detect Salmonella sp. as early as 18-48 hours during pre-enrichment and enrichment compared to isolation on XLT4, which required an overnight incubation step for the presumptive isolation and identification of Salmonella.  相似文献   

3.
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   

4.
The aim of the present evaluation was to assess the efficacy of blends of organic acids and oregano extracts supplied from d 1 to 21 and from d 35 to 42 in feed, drinking water, or both, in controllingSalmonella Enteritidis persistence in the crop and ceca of broiler chicken. A total of 105 one-day-old male broiler breeder chicks were randomly distributed into 5 different treatments according to the supply of referred blends andSalmonella Enteritidis challenge.Salmonella Enteritidis was inoculated directly in the crop of birds at the 15 d of age. Treatments were unsupplemented unchallenged, unsupplemented challenged, supplemented through water and challenged, supplemented through feed and challenged, and supplemented through feed and water and challenged. Use of the additives in feed and water and in water alone efficiently controlledSalmonella shedding and reduced cecal persistence. Immune mechanisms involved are proposed.  相似文献   

5.
An antigen-capture, monoclonal-antibody-based enzyme-linked immunoassay (ELISA) that detects a broad range of Salmonella serovars in various serogroups was developed and compared with standard culture procedures for detection of Salmonella in 1055 field samples collected from poultry-hatchery environments. The diagnostic sensitivity of the ELISA relative to culture was 99.9% and the diagnostic specificity 99.6%. The extensive culture procedure included nonselective enrichment (NSE) as well as primary selective enrichment (PSE) and delayed secondary enrichment (DSE) with Hajna tetrathionate (TT) and Rappaport–Vassiliadis (RV) selective-enrichment broths. Significantly more Salmonella-positive samples were detected by ELISA and culture at the DSE stage than at the NSE and PSE stages (P < 0.05). Significantly more RV than TT broths were positive for Salmonella by culture and ELISA by the DSE stage (P < 0.05). This ELISA procedure could be a reliable screening test for the detection of Salmonella in hatchery samples.  相似文献   

6.
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   

7.
A Canada-wide flock management survey of 294 randomly selected commercial broiler chicken flocks was conducted during 1989-1990. The prevalence of flocks that yielded Salmonella from cultures of floor litter or drinking water, and the prevalence of floor litter samples that yielded Salmonella, were significantly associated (p < 0.05) with the age of the flock and the region of Canda in which the flock was located. Culture of Salmonella from the drinking water was significantly associated (p < 0.05) with the type of drinker used, the dead bird disposal method, and the region of Canada in which the flock was located. There was a significantly greater risk (p < 0.05) of contamination of drinking water with Salmonella from trough drinkers (odds ratio = 7.99) and plastic bell drinkers (odds ratio = 6.10) than from nipple drinkers. No significant associations were found between pest control, restrictions on visitors, clean-out methods, or water sanitization and the culture of salmonellae from floor litter or drinking water.  相似文献   

8.
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   

9.
Fifteen floor litter samples were collected from each of 60 broiler chicken houses in Nova Scotia. Salmonella was recovered from 270 litter samples (30%) in 33 of 60 (55%) houses. All isolates were serotyped. Salmonella heidelberg and S. infantis were the most common of the 13 serotypes found. Isolates of selected serotypes were phage typed. Most isolates were susceptible to all common antimicrobial agents.  相似文献   

10.
The effect of duration of feeding (continuous or discontinued after d 14) and form (granular vs. powder) of spray-dried plasma (SDP) on performance and mortality of broilers using used litter was evaluated with 240 Ross × Ross 308 male broilers (6 broilers per pen, 8 pens per treatment). Dietary treatments were control (no SDP) or SDP as powder or granular included in the pellet and fed continuously (d 0 to 35) or discontinued after d 14. During the experiment, broilers developed necrotic enteritis, and tissue cultures were positive for Escherichia coli and Salmonella, resulting in 50% mortality on control broilers. Addition of SDP to the feed improved (P < 0.05) average daily gain, feed intake, and feed efficiency for each period of the study (d 0 to 14, 15 to 28, 29 to 35, and 0 to 35). Continuous feeding of SDP improved (P < 0.05) average daily gain, feed intake, and feed efficiency from d 15 to 35 compared with broilers fed SDP to d 14. Liveability was improved (P < 0.05) in broilers consuming SDP either for 14 d or continuously throughout the experiment compared with control broilers. Spray-dried granular plasma was more effective than spray-dried powder plasma from d 0 to 14. The results of this experiment confirmed that SDP improved broiler growth rate, feed intake, feed efficiency, and minimized enteric challenge associated with necrotic enteritis with maximal protection afforded by continuous feeding. The response to SDP was independent of age of the broiler.  相似文献   

11.
Foot pad dermatitis (FPD), a condition of inflammation and necrotic lesions on the plantar surface of the footpads, is commonly observed in fast‐growing broiler chickens and turkeys. FPD negatively affects the welfare of birds, performance indices and the economic profit of poultry meat production. Nutrition is an important factor affecting water intake, excreta moisture and litter quality and, in this way, the occurrence and intensity of FPD in birds. This article reviews and discusses the recent results published in the literature on the effects of nutritional factors on litter quality and FPD severity in broiler chickens and turkeys. Literature data on the efficacy of nutritional methods on the litter quality and FPD occurrence are not consistent. However, the results of several experiments indicate that the optimal level of crude protein, biotin and electrolytes (Na, K) in the diet, as well as feed additives such as feed enzymes hydrolysating non‐starch polysaccharides and organic sources of microelements (zinc), may reduce the litter moisture as well as FPD incidence and severity in broiler chickens and turkey.  相似文献   

12.
Although numerous studies have documented the use of surrogate organisms for the evaluation of pathogens in human food, reports on the use of such organisms for similar studies in animal feed are limited. In the current study, dry feed inocula of Salmonella Typhimurium cells or Bacillus stearothermophilus spores were prepared and used to evaluate the efficiency of sterilization during feed extrusion. The inocula were placed in sealed stomacher bags and kept under 4° C refrigerated storage, where they remained stable for the 8-wk study period. Test feed batches were inoculated with the dry feed inocula of Salmonella Typhimurium or B. stearothermophilus spores, and the batches were then extruded by using a single-screw extruder set to various processing stringencies according to a designed experimental protocol. Only thermophilic B. stearothermophilus could be recovered from the test feed samples over the entire range of extrusion processing stringencies used (245 to 345 g of moisture/kg of feed; 3 to 11 s of feed retention time in the extruder barrel; and 77 to 110° C extruder barrel exit temperature). It was concluded that B. stearothermophilus is a suitable surrogate organism for evaluating the sterilization efficiency of feed extrusion and for identifying the optimal processing conditions to use during feed extrusion to eliminate, or at least minimize, the incidence of mesophilic and thermotolerant pathogens in feed.  相似文献   

13.
In this study, we investigated risk factors associated with the probability to detect Salmonella in samples of litter collected within 2 h prior to new flock placement in 76 grow‐out houses on 38 conventional broiler farms located in the US states of Mississippi, Alabama and Texas. We evaluated characteristics of location and layout of the farm; area adjacent to and surrounding the house; house construction; condition and type of equipment in the house; litter management and other production, sanitation, visitation and biosecurity practices; non‐broiler animal species on the farm; and weather conditions on the 3 days leading up to flock placement. Logistic regression was used to model the relationships between probability to detect Salmonella in litter and potential risk factors. In the screening process, each risk factor was evaluated as a single fixed effects factor in a multilevel model that accounted for variability among the sampled farms and their production complexes and companies. Of almost 370 risk factors screened, 24 were associated with the probability to detect Salmonella in litter. These were characteristics of the surroundings of the house, house construction and conditions, litter management, length of downtimes between flocks in the house, biosecurity and farm location. After investigation of collinearity between these variables and building of models for important risk factor categories, the list of candidate variables for the final model was refined to eight factors. The final model demonstrated that a higher probability of detecting Salmonella in litter was strongly associated with the use of wood to construct the base of the walls or to cover the inside of the broiler house foundation, and with the use of fresh wood shavings to top‐dress or completely replace the litter between flocks.  相似文献   

14.
Three commercial products, a partially defined chicken-origin competitive exclusion culture (Aviguard, 0.50 mL/chick) and 2 single-organism probiotic cultures (Saccharomyces cerevisiae, Levucell SC, 1 g/kg of feed, and Pediococcus acidilactici, Bactocell, 100 mg/kg of feed) were evaluated for their ability to reduce Salmonella in broilers and their effects on production performance. It was found that all the treatments significantly (P < 0.05) reduced Salmonella concentrations, as compared with the control, on the chicken, in the ceca, and on the chicken carcass. In addition, it was found that these treatments had no adverse effect on any of the production parameters that were measured. Finally, this study showed the importance of using these preharvest treatments as part of an integrated program to control Salmonella at the broiler farm.  相似文献   

15.
Poultry are normally reared on bedding materials such as wood shavings or rice hulls. Poultry litter reuse for multiple flocks has become economically important in modern broiler production. However, this practice results in the litter serving as a reservoir of numerous microbial organisms, including, yeasts, molds, multiple types of viruses, and bacterial pathogens such as Salmonella, Escherichia, Campylobacter, Clostridium, Staphylococcus, and Pseudomonas. The foodborne pathogens are of particular importance for poultry producers. During the preharvest feed withdrawal period, consumption of contaminated litter and feces by the birds can lead to infection of the upper gastrointestinal tract with Salmonella, which presents substantial problems at processing. The current study was conducted to determine whether the use of a liquid bacterial product (LBP), such as LT1000, could reduce the load of Salmonella Typhimurium in poultry manure. The LBP was added to sterile poultry manure then challenged with 108 cfu/mL of Salmonella Typhimurium. The concentration of Salmonella Typhimurium was measured over 9 d or until the Salmonella Typhimurium was no longer detected. In 91% of the trials, Salmonella Typhimurium was completely eliminated within 9 d. This demonstrates that the LBP used in the current study has the potential to substantially improve the overall microbiological safety of used poultry litter.  相似文献   

16.
Salmonella and Campylobacter are frequent colonizers of the intestinal tracts of poultry and have often been associated with human foodborne illness. The entry, transmission, and prevalence of both pathogens have been extensively studied in chickens but little information is available for turkeys. This project monitored turkey breeder hens and toms from d of hatch to 65 wk of age with the objective of determining routes of transmission for Salmonella and Campylobacter throughout the turkey production cycle. Breeder poults were separated by sex and then into 2 groups (control and inoculated) for each sex. The inoculated group was orally gavaged with marker strains of both Salmonella and Campylobacter. The inoculated groups (toms and hens) were placed on the opposite side of a growout house from the uninoculated groups. Fecal samples, intestinal samples and organs, feed, drinkers, and potential vectors such as insects and mice, were analyzed at different times until 65 wk. Monitoring showed that Campylobacter spread rapidly and cross-contaminated turkeys throughout the growout house. For both Salmonella and Campylobacter, naturally occurring strains that were first isolated in control groups at wk 3 and 4, respectively, outcompeted marker strains several wk post inoculation and persisted in the flock. The most common naturally occurring strains were C. jejuni (tetracycline resistant), C. coli (kanamycin resistant), and S. Agona. Campylobacter and Salmonella also were isolated from flies and from a mouse, confirming the importance of proper pest control and biosecurity to reduce the spread of the bacteria.  相似文献   

17.
Litter was collected from four turkey farms (eight houses) with a history of fluoroquinolone (FQ) treatment failure, 10 adult broiler breeder chicken farms (43 houses) with one having a history of FQ treatment, and 30 broiler chicken farms (110 houses) with 24 having a history of FQ treatment. In the turkey litter, the percentage of nalidixic acid-resistant (at 100 microg/ml) coliforms/total number of coliforms ranged from 0.6% to 61.9%. Two of the four farms had houses containing coliforms resistant to the two FQs, enrofloxacin (1 microg/ml) and sarafloxacin (1 microg/ml). There was also multiple resistance to other antimicrobials on all four turkey farms (ampicillin, tetracycline, chloramphenicol, kanamycin). The level of total coliforms from the adult broiler breeder litter was low, and there were no nalidixic acid-resistant isolates from any of the 10 farms. In the broiler chickens, 7 of 91 houses with a history of FQ usage contained coliforms resistant to nalidixic acid; however, 2 of the 19 houses on farms with no history of FQ usage had nalidixic acid-resistant coliforms. All of the broiler farms with nalidixic acid-resistant isolates were also resistant to the FQ sarafloxacin, whereas only 3 of the 24 treatment history farms and 1 of the no-treatment history farms exhibited enrofloxacin-resistant coliforms in the litter.  相似文献   

18.
The ability of 2 probiotic cultures (P1 and P2) to reduce environmental Salmonella in commercial turkey flocks 2 wk prior to processing with or without the use of a commercial organic acid (OA) was evaluated. Salmonella-positive flocks were identified 3 to 4 wk before processing by using standard assembled drag swabs. Two weeks after treatment (prior to live haul), drag swabs were used again for Salmonella recovery. In the first trial, 6 Salmonella-positive houses were selected to evaluate 4 treatments: P1 (1.0 × 108 cfu/mL), OA + P1 (1.0 × 108 cfu/mL), OA + P1 (1.0 × 106 cfu/mL), and OA + P2 (1.0 × 106 cfu/mL). Two weeks after treatment, reductions (P <0.05) of Salmonella recovery (90, 100, 100, and 86%, respectively) were observed in all treatments. In the second trial, 22 Salmonella-positive houses were selected to evaluate 6 treatments: control, OA, P1, P2, OA + P1, and OA + P2. Two weeks after treatment, the recovery of Salmonella was significantly reduced (P <0.05) in houses in which P1 and P2 cultures were administered in combination with the OA product. Our results suggest that the administration of selected probiotic candidate bacteria in combination with OA may reduce environmental Salmonella in turkey houses prior to live haul, and that this practice could help to reduce the risk of Salmonella cross-contamination in the processing plant.  相似文献   

19.
An observational study was conducted of chicken and turkey flocks slaughtered at federal processing plants in the province of Quebec, Canada. The objectives were to estimate prevalence of drug use at hatchery and on farm and to identify antimicrobial resistance (AMR) in cecal Escherichia coli and Enterococcus spp. isolates and factors associated with AMR. Eighty-two chicken flocks and 59 turkey flocks were sampled. At the hatchery, the most used antimicrobial was ceftiofur in chickens (76% of flocks) and spectinomycin in turkeys (42% of flocks). Virginiamycin was the antimicrobial most frequently added to the feed in both chicken and turkey flocks. At least 1 E. coli isolate resistant to third-generation cephalosporins was present in all chicken flocks and in a third of turkey flocks. Resistance to tetracycline, streptomycin, and sulfisoxazole was detected in > 90% of flocks for E. coli isolates. Antimicrobial resistance (AMR) was observed to bacitracin, erythromycin, lincomycin, quinupristin-dalfopristin, and tetracycline in both chicken and turkey flocks for Enterococcus spp. isolates. No resistance to vancomycin was observed. The use of ceftiofur at hatchery was significantly associated with the proportion of ceftiofur-resistant E. coli isolates in chicken flocks. In turkey flocks, ceftiofur resistance was more frequent when turkeys were placed on litter previously used by chickens. Associations between drug use and resistance were observed with tetracycline (turkey) in E. coli isolates and with bacitracin (chicken and turkey), gentamicin (turkey), and tylosin (chicken) in Enterococcus spp. isolates. Further studies are needed to provide producers and veterinarians with alternative management practices and tools in order to reduce the use of antimicrobial feed additives in poultry.  相似文献   

20.
Salmonella contamination of 71 chicken broiler flocks was investigated at the slaughterhouse in Reunion Island between October 2007 and January 2009. Samples were collected from live broiler chickens and chicken carcasses as well as the slaughterhouse environment. Salmonella spp. was isolated from 40 of 71 (56 % with a confidence interval 5 % [45–67]) broiler chicken flocks at slaughter. The most prominent serovars were Blockley (31 %), Typhimurium and Brancaster (14 %), Hadar (10 %), Salmonella multidrug resistant clinical organisms serotypes 1,4,[5],12:i:-, and Virchow (8 %) and Livingstone, St. Paul, Seftenberg, Llandoff, Infantis and Indiana. At the farm, 27 % of the broiler chicken flocks tested positive for Salmonella spp. Salmonella spp. was isolated from 124 of 497 environmental samples (25 %). In most cases, there was no relationship between pulsed field gel electrophoresis (PFGE) pattern and antibiotic resistance pattern. The predominant Salmonella serovars were susceptible to most of the tested antibiotic drugs, but S. Hadar exhibited multidrug resistance. This study highlighted the primary source of Salmonella was the farm of origin and downstream stages in processing could not remedy to but amplify this Salmonella contamination.  相似文献   

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