Profile of selected bacterial counts and Salmonella prevalence on raw poultry in a poultry slaughter establishment.

The USDA Food Safety and Inspection Service determined populations of bacteria on poultry during processing at a slaughter plant in Puerto Rico in November and December 1987. The plant was selected because of its management's willingness to support important changes in equipment and processing procedures. The plant was representative of modern slaughter facilities. Eight-hundred samples were collected over 20 consecutive 8-hour days of operation from 5 sites in the processing plant. Results indicated that slaughter, dressing, and chilling practices significantly decreased the bacterial contamination on poultry carcasses, as determined by counts of aerobic bacteria, Enterobacteriaceae, and Escherichia coli. Salmonella was not enumerated; rather, it was determined to be present or absent by culturing almost the entire rinse. The prevalence of Salmonella in the study decreased during evisceration, then increased during immersion chilling.     

Salmonella contamination of poultry flocks in The Netherlands

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.     

Continuous disinfection as a means to control infectious diseases in poultry. Evaluation of a continuous disinfection programme for broilers

A full continuous disinfection programme, consisting of disinfection during cleanout of poultry houses prior to placement of chickens, disinfection of the drinking water and spray disinfection of the birds during production was evaluated in broilers under experimental condition as well as under field conditions. Under controlled conditions, the experimental design consisted of three groups, two of which were control groups. Each group comprised 300 chickens. In one of the control groups, no disinfection of the pens was undertaken prior to the placement of the chickens. In the other control group, disinfection of the pens prior to placement of the birds was carried out using a glutaraldehyde-based product. In the test group, disinfection prior to placement was done. The drinking water of these birds was treated continuously and the birds were sprayed with a non-toxic disinfectant during production. Production parameters, such as growth rate, feed conversion ratio and feed consumption, of the birds in the three groups were monitored. In addition, all mortalities in the different groups were recorded and classified into diseases of an infectious nature, non-infectious nature and unknown category. Bacterial counts were also done on a weekly basis from the different pens. In this experiment, it was shown that the full continuous disinfection programme resulted in a lower number of mortalities caused by infectious agents as well as a reduction in the bacterial counts in the pens treated with the full continual disinfection programme. The full continuous disinfection programme was also tested on a commercial poultry farm in the Northern Cape Province of South Africa. Two production houses of 3,500 birds were randomly selected as test houses for the full continuous disinfection programme. Another similar house, which received day-old chicks from the same batch as the other two houses, was selected as the control house; it received the routine disinfection procedure prior to placement of the chicks. During the course of this experiment, a severe outbreak of Newcastle disease was experienced on this farm. It was demonstrated that, in the face of this severe challenge, the full continuous disinfection programme controlled the spread of the disease in both the houses where it had been applied at a stage when in every other house (including the control house) on the farm birds were suffering very high mortalities.     

Simulation model for Campylobacter cross-contamination during poultry processing at slaughterhouses

Broiler meat is regarded as the most common source of Campylobacter infection and risk management measures are required to reduce broiler meat contamination. Among the quantitative risk assessments for Campylobacter in broiler meat, evaluation of the poultry processing stage is particularly important for predicting the contamination level of broiler meat and the effects of control measures. In this study, we built a simulation model for cross‐contamination during poultry processing focusing on Campylobacter contamination at the individual carcass level. Using this model, we examined changes in the prevalence of contaminated carcasses and the number of Campylobacter per carcass after processing. As a result, it was found that the prevalence and number of Campylobacter after processing were largely influenced by the number of Campylobacter on the contaminated carcasses before processing. In the baseline model, where it was assumed that the mean number of Campylobacter on contaminated carcasses before processing was 4.7 log₁₀ cfu per carcass, the prevalence after processing was less than that before processing. Although the median value of Campylobacter on contaminated carcasses was reduced after processing, the distributions after processing became wider and the upper limit of the 95% credible interval of Campylobacter on contaminated carcasses remained elevated. The individual‐based simulation model can trace individual level changes considering discrete interactions, while models tracing mean values cannot handle these interactions in detail. The individual‐based approach is considered useful for modelling cross‐contamination among individual carcasses during poultry processing.     

Risk factors for Listeria monocytogenes contamination in French laying hens and broiler flocks

The objective of this study was to identify potential risk factors for Listeria monocytogenes contamination in French poultry production. Eighty-four flocks of layer hens kept in cages and 142 broiler flocks were included in this study. For each production type, a questionnaire was submitted to farmers and fecal samples were taken to assess the L. monocytogenes status of the flocks during a single visit to the farm. Two logistic regression models (specific to each production) were used to assess the association between management practices and the risk of L. monocytogenes contamination of the flock. The prevalence of L. monocytogenes-positive flocks was 30.9% (95% CI: 21.0; 40.9) and 31.7% (95% CI: 24.0; 39.4) for cage-layers and broiler flocks, respectively. For layer flocks, the risk of L. monocytogenes contamination was increased when pets were present on the production site. When droppings were evacuated by conveyor belt with deep pit storage, the risk of L. monocytogenes contamination decreased significantly. Feed meal was found to be associated with a higher risk of L. monocytogenes contamination than feed crumb. For broiler flocks, the risk of L. monocytogenes contamination was increased when farmers did not respect the principle of two areas (clean and dirty) at the poultry house entrance. A first disinfection by thermal fogging and the absence of pest control of the poultry house before the arrival of the next flock was found to increase the risk of contamination. When litter was not protected during storage and when farm staff also took care of other broiler chicken houses, the risk of L. monocytogenes contamination increased significantly. In the case of the watering system, nipples with cups were found to decrease the risk of contamination.     

A Microbiological Assessment of On-Farm Food Safety Cleaning Methods in Broiler Barns

Little is known about the effectiveness of current poultry industry cleaning and disinfection procedures in broiler barns. Surface swabs were taken from a commercial broiler barn and a research broiler barn. The swabs were analyzed to determine if cleaning and disinfectant processes used would reduce the numbers of total aerobic bacteria and the total Enterobacteriaceae on the walls of the commercial barn (Experiment 1) and on the walls and floor of the research barn (Experiment 2). Microbiological analyses were used to assess bacterial loads within each barn. In Experiment 1 the mean of total aerobic bacterial counts were not affected by the cleaning and disinfectant process. However, the means of total Enterobacteriaceae counts were significantly reduced by the washing process. Disinfection with Virkon did not further reduce the numbers of Enterobacteriaceae. In general, the cleaning processes used in wood and metal barns were effective in reducing Enterobacteriaceae counts. In Experiment 2, neither the mean of total aerobic bacterial counts nor Enterobacteriaceae counts were affected by the washing process. However, disinfection with Virkon did result in a significant reduction of bacterial numbers. In summary, the disinfectant step performed in the research barn was effective in decreasing both total aerobic and Enterobacteriaceae counts.     

Use of epidemiologic markers to identify the source of Escherichia coli infections in poultry

During an epidemiologic study of poultry colisepticemia on 2 Saudi Arabian poultry broiler farms, Escherichia coli was isolated from 101 (40.4%) of the 250 specimens examined. The antigenic structure and the drug resistance pattern of 65.4% of the E coli isolates from different sources were used as epidemiologic markers to trace the source of the infection. The predominant E coli serotypes involved in infections of 2 poultry broiler progeny farms were 033:H4 (51.8%) and 078:H- (19.6%) that had the following respective drug resistance patterns: furazolidone-streptomycin-sulfathiazole and streptomycin-sulfathiazole-tetracycline. Escherichia coli strains with typical epidemiologic markers were isolated from various sources on a broiler breeding farm, but not from well waters of the infected progeny farm. Three other E coli serotypes (045:H10[14.3%], 0119:H27[1.8%], and 0145:H25[1.8%]) were involved in poultry infection, but to a lesser extent. These 3 serotypes were multiply resistant against 5 to 6 of the antimicrobials evaluated.     

Effect of boiling water carcass immersion on aerobic bacteria counts of poultry skin and processed ground poultry meat

This study was conducted to determine the relationship between bacteria destruction on poultry carcass skin and bacteria in raw ground poultry meat from the same carcasses. Immersion time in boiling water of broiler chicken whole carcasses required for maximum reduction of naturally occurring aerobic bacterial count on skin was measured. Treatments for chicken carcasses consisted of immersion in boiling water (approximately 95 degrees C) for 0, 0.5, 1, 1.5, 2, 2.5, 3, 3.5, and 4 min. Four skin samples taken following treatment and three taken from subsequently ground carcass meat were analyzed for total aerobic plate counts (APC). Analysis of the data indicated a linear increase in bacterial destruction on skin with increased boiling water immersion time from 0 to 4 min. Reduction of skin bacteria to less than 1 log10 occurred at 3 min carcass immersion or longer. The analysis also indicated that treatment with boiling water and removal of skin was effective in reducing bacterial counts in ground meat to similar levels at all treatment times from 0.5 to 4.0 min. Findings from this study indicated that a boiling water immersion intervention and removal of skin could reduce subsequent bacteria contamination of ground meat. This intervention could minimize the risk of pathogen-contaminated primary processed poultry carcasses used in further processing.     

Relationship between serotypes of Salmonellae from hatcheries and rearing farms and those from processed poultry carcases

The influence of the hatchery and the poultry farm on the contamination of poultry carcases by Salmonella species has been studied by examining samples from different stages of production. The incidence of Salmonella serotypes in the hatchery varied considerably in different broiler flocks and decreased from the beginning to the end of the rearing period. Serotypes originating in the hatchery were less important in the final product than those present in the house, or those introduced into the house by vectors during rearing.     

2021年山东省家禽养殖场生物安全水平问卷调查

为了解山东省家禽养殖场的生物安全水平,以问卷调查方式,对养殖场基本信息、场内区域划分、免疫接种、引种购进、消毒、饲养管理等问题展开调查。经预调查后,2021年6—7月在全省范围内开展本次调查。在全省16个地级市,采用随机抽样方式,每地级市抽检1~2个县(市、区);应用配额采样方式,在县市域内选取蛋鸡养殖场、肉鸡养殖场以及种禽场各1家。共收到有效问卷141份,分别来自12个地级市36个县(市、区),其中来自蛋鸡养殖场、肉鸡养殖场和种禽场占比分别为63.83%、26.95%和9.22%。所调查养殖场中,按照管理区、生产区、生活区进行区域划分的133家,一半以上的养殖场能做到每周至少消毒1次;137家养殖场有免疫计划,而无免疫计划的只有4家,包括蛋鸡场1家、肉鸡场3家。肉鸡场没有隔离场所的占比最高,达44.7%。106家养殖场对患病动物进行无害化处理。结果表明,所调查家禽养殖场在区域划分、区域管理、消毒管理、环境控制等生物安全方面都进行了相关的设计和应用,在一定程度上,能够起到预防致病因子侵入、阻挡病原微生物扩散的作用,但不同类型养殖场的生物安全水平并不均衡,因此养殖场需继续提高生物安全意识,逐步建立适用于本场的生物安全体系。     

The incidence of clostridia in poultry carcasses and poultry processing plants

An investigation of the incidence and types of clostridia was carried out as part of a bacteriological examination of poultry carcasses and plant swabs. From 19 per cent to 35 per cent of chicken carcasses from four processing plants were contaminated with clostridia in the “total” differential reinforced clostridial medium count whereas 27–5 per cent to 83–5 per cent were contaminated with clostridial spores. Swabs of equipment and personnel (hands and aprons) in three of the plants showed that from 15 per cent to 75 per cent of the samples were positive for “ total” clostridia, and from 33 per cent to 85 per cent positive for clostridial spores. Clostridium welchii was recovered from all poultry plants but the incidence varied widely between the four plants sampled. The organisms isolated were Cl. bifermentans, Cl. histolyticum, Cl. butyricum, Cl. sporogenes and Cl. welchii. The majority of Cl. welchii isolates were from spore counts.     

Evaluation of the performance of different cleaning treatments in reducing microbial contamination of poultry transport crates

1. The present systems for cleaning the plastic crates (drawers) used to transport live poultry to the processing plant are known to be inadequate for removing microbial contamination. 2. To investigate possible improvements, a mobile experimental rig was constructed and operated in the lairage of a poultry processing plant. The cleaning rig could simulate the conditions of commercial cleaning systems and utilise freshly emptied crates from the processing plant. 3. The aim of the study was to improve cleaning by enhancing the removal of adherent organic material on the crates and by reducing microbial contamination by at least 4 log(10) units. 4. Trials showed that the most effective treatments against Campylobacter were either (a) the combination of soaking at 55 degrees C, brushing for 90 s, washing for 15 s at 60 degrees C, followed by the application of disinfectant (Virkon S in this study) or (b) the use of ultrasound (4 kW) at 65 degrees C for 3 to 6 min, with or without mechanical brushing of crates. 5. Both of these treatments also achieved a 4 log(10) reduction or more in the counts of Enterobacteriaceae but were less effective in reducing aerobic plate counts. 6. It was noted that there was little correlation between the visual assessment of crate cleanliness and microbiological counts. 7. It was concluded that the demonstrated enhanced cleaning could contribute significantly to overall hygiene control in poultry meat production.     

Microbiological aspects of poultry processing

The microbiological condition of poultry carcasses is shown to be influenced by the general hygiene in the processing plant which is largely determined by (i) the quality of the raw materials, (ii) the design of plant and buildings, (iii) personal hygiene and (iv) cleaning efficiency. The standard of hygiene is dealt with under (i) assessment of contamination on surfaces, (ii) estimation of contamination on carcasses, including bacteria of public health significance and (iii) other measurements of value. Microbiological sampling of surfaces and carcasses is discussed and standards are suggested for water supplies, surfaces and carcasses. Data are presented from 430 frozen eviscerated carcasses sampled over the period of 12 months from a large processing plant.     

Campylobacter spp. in broiler flocks at farm level and the potential for cross-contamination during slaughter

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.     

Comparison of Staphylococcus aureus recovered from personnel in a poultry hatchery and in broiler parent farms with those isolated from skeletal disease in broilers.

Personnel from one broiler hatchery, and workers on 18 separate broiler parent farms which supply the hatchery, were tested for hand and nasal carriage of Staphylococcus aureus. In both locations, nasal carriage of S. aureus was more common than hand carriage. A total of 63 S. aureus strains were characterised by biotyping, protein A analysis and pulsed field gel electrophoresis (PFGE) typing. Of these, 36 were recovered from broiler hatchery personnel, 14 from broiler parent farm personnel and 13 from cases of skeletal disease in commercial broilers. Biotyping and protein A analysis indicated that none of the strains recovered from hatchery personnel were of the poultry biotype, but that two strains recovered from the hands of two broiler parent farm personnel could be grouped together with 12/13 of strains recovered from skeletal disease in broilers, as poultry biotypes. PFGE-typing could not distinguish 9/13 strains recovered from skeletal disease in broilers and one of the strains from the broiler parent farm personnel from isolate 24 (I. 24), which is the predominant S. aureus strain type associated with clinical disease in N. Ireland broiler flocks. The present study found no evidence of nasal carriage of S. aureus strains of poultry biotype by humans. The finding of hand carriage by broiler parent farm personnel, suggests that handling by personnel may contribute to the dissemination of I. 24 or other S. aureus strains associated with skeletal disease in broilers.     

Airborne micro‐organisms in poultry processing plants

The levels of aerobic micro‐organisms in the air of four poultry processing plants were determined. High total counts were obtained in the intake bay and plucking areas of all plants and in the eviscerating, trussing and packing areas and chilled holding‐room at one plant. Numbers were generally fairly low in the latter areas of the other plants, as were counts of coli‐aerogenes and yeasts and moulds. Staphylo‐coccus aureus was found in the air of all the areas in one plant, but these were shown not to be of human origin. Salmonellae were not found in any of the samples. The contribution of the micro‐organisms in the air to final contamination on carcasses should not be high under normal operating conditions if the intake bay and plucking areas are well sealed off from the other parts of the plant.     

Determination of the incidence of Salmonella spp., Campylobacter jejuni, and Clostridium perfringens in wild birds near broiler chicken houses by sampling intestinal droppings

Several methods were evaluated for collecting fecal and intestinal samples from wild birds found near broiler chicken houses. A few intestinal samples and cloacal swabs were obtained from European starlings and house sparrows. Most of the samples collected consisted of wild bird droppings found on or near the houses. Samples were collected from each of four farms of a broiler integrator during a grow-out cycle: a cycle in the summer for farm A, fall for farm B, and spring, summer, fall, and winter for farms C and D. Of the 25 wild bird intestinal and fecal samples collected from a broiler house on farm A during a grow-out cycle in July-August 1997, 24% were positive for Salmonella spp., 4% for Campylobacter jejuni, and 28% for Clostridium perfringens. Of the nine fecal samples collected from broiler house B in a grow-out cycle in September-November 1997, 33% were positive for Salmonella spp., 11% for C. jejuni, and 22% for C. perfringens. For farms C and D, of the 23 samples collected in March-April 1998, 0 were positive for Salmonella spp., 11% for C. jejuni, and 52% for C. perfringens; of 27 samples collected in June-July 1998, 4% were positive for Salmonella spp., 0 for C. jejuni, and 13% for C. perfringens; of 24 samples collected in August-October 1998, 14% were positive for Salmonella spp., 5% for C. jejuni, and 4% for C. perfringens; of 14 samples collected December 1998-January 1999, 0 were positive for Salmonella, 50% for C. jejuni, and 14% for C. perfringens. The incidence of these bacterial enteropathogens in wild birds near the broiler chicken houses suggests that wild birds that gain entry to poultry grow-out houses have the potential to transmit these pathogens to poultry.     

Persistence of salmonella enteritidis in poultry units and poultry food

1. Studies on the survival of Salmonella enteritidis in poultry units and food were carried out over a two‐year period.

2. The organism persisted for at least one year in an empty trial house at the laboratory in which naturally‐infected broiler breeder birds had previously been housed. A similar survival period was seen in a building which had housed an infected layer breeder flock, although infection was not detected in a subsequent pullet flock.

3. Salmonella enteritidis was also frequently found surviving outside poultry houses in small pockets of litter and fan dust which had been left after cleansing and disinfection of the site. On some poultry units S. enteritidis was also found in wild bird droppings.

4. Salmonella contamination appeared to persist preferentially in association with dust particles swept from the floor and in food troughs and S. enteritidis survived at least 26 months in artificially contaminated poultry food.     

Dissemination and tracking of Salmonella spp. in integrated broiler operation

Controlling Salmonella in integrated broiler operation is complicated because there are numerous potential sources of Salmonella contamination, including chicks, feed, rodents, wild poultry operations, and the processing plant. The objective of this study was to investigate the distribution of Salmonella through all phases of two integrated broiler operations and to determine the key areas related to the control of all known sources of infection. Two different Salmonella serotypes were observed at integrated broiler chicken company A. S. enteritidis, the predominant company A isolate, was consistently found in the breeder farm, hatcheries, broiler farms, and chicken slaughterhouse. At company B, a total of six different serotypes, S. heidelberg, S. senftenberg, S. enteritidis, S. blockley, S. gallinarum, and S. virchow, were detected. Although S. heidelberg was not found in the broiler farms, it was consistently found in the breeder farm, hatcheries, and chicken slaughterhouse. In addition, S. enteritidis was found in the hatcheries, broiler farm, and chicken slaughterhouse. In order to obtain the genetic clonality, 22 S. enteritidis isolates were digested with XbaI and analyzed by pulsed-field gel electrohporesis (PFGE). A difference in the PFGE pattern was found to be related to the origin of the integrated broiler operation. These data support the critical need to control Salmonella in breeder farms and hatcheries, and demonstrate important points related to the control of infection in large-scale poultry operations of Korea.     

Effect of poultry by-product meal on pulmonary hypertension, right ventricular failure and ascites in broiler chickens

We tested the hypothesis that poultry by-product meal would produce a thermogenic response (an increased requirement for oxygen) resulting in an increased incidence of pulmonary hypertension with right ventricular failure and ascites in commercial broiler chickens.

Four treatment groups, each with three replicates of 40 chicks, were fed a commercial broiler starter to day 21, grower to day 35, and the following experimental diets after day 35: group 1, commercial chicken broiler finisher; group 2, commercial chicken broiler finisher with poultry by-product meal added to replace part of the soyabean meal; group 3, commercial chicken broiler finisher with poultry fat added to replace the animal-vegetable (AV) fat; group 4, commercial chicken broiler finisher with both poultry by-product meal and poultry fat added to replace soyabean meal and AV fat. On day 35, pen temperature was reduced to 15°C, and on day 42 to 12°C.

Mortality from ascites between days 35 and 56 was 11(9%) in group 2, 5(4%) in group 4 and 3(2.5%) in groups 1 and 3 The incidence of pulmonary hypertension, as measured by an increased right ventricle: total ventricle (RV:TV) ratio (RV:TV > 0.249) at processing on day 57, was higher in the groups receiving poultry by-product and poultry fat: 27(22.5%) in group 2, 26(21.7%) in group 3, and 20(16.7%) in group 4 compared to that of the controls 12(10%).