Epidemiology of Salmonella derby strains isolated from swine, pork and pork products

A total of 35 Salmonella derby strains, isolated from 6 types of samples of porcine origin from 9 different places in Hungary were examined for their characteristics. Thirty-two strains (91%) were of phage type 25, 2 (6%) of phage type 15 and 1 (3%) of phage type 58. Colicin production was observed in 3 (9%) strains. Five strains (14%) were found to be resistant to tetracycline (Tc). The strains harboured plasmids of 2.2, 2.4, 3.4, 4.2 and 72 Md. The 72 Md plasmid appears to be characteristic of S. derby and possibly encodes Tc resistance. The 72 Md plasmid belonged partly to incompatibility (Inc) group I1, while the other plasmid of the same size belonged to Inc. group B. The findings suggest that healthy salmonella carrier pigs carried the infection from the farm to the abattoir. Slaughtering of infected pigs may have led to contamination of the carcasses and, thereafter, that of the pork and pork products.     

巴西猪肉产量将继续增长

<正>全球猪肉需求量和出口量的增长,将继续使巴西的专业养猪户受益。巴西目前生猪存栏量3000万头,年产猪肉300万t,直接或间接提供了63万个工作岗位,猪肉主产区主要集中在巴西的南部和东南部,猪肉消费也主要集中于该地区。     

Update: prevalence of Salmonella in pork sausage

One hundred seventy-five samples of fresh pork sausage representing thirty-five different commercial brands from six different retail stores were examined for the presence of salmonellae by standard enrichment, plating, biochemical and serological techniques. Contamination levels varied from 0 to 50% among stores and from 0 to 28% among brands. Prior research implied reduced prevalence of salmonellae in fresh pork sausage; however, these results indicate no variation in prevalence since 1969.     

Epidemiological investigations into the sources of Salmonella contamination of pork

This study was conducted to elucidate which phases of the pork production chain contribute to the Salmonella contamination on pork after slaughter. During 7 sampling days, samples were collected of randomly selected slaughter pigs and of pigs from selected Salmonella-infected and Salmonella-free herds, trucks, lairages, and slaughterlines, in two slaughterhouses. Salmonella genotypes, present on pork after slaughter, were compared with Salmonella types, present on the farm, in the truck, in the lairage, on slaughter equipment, and in pigs from other herds. Results showed that the slaughterline was the most important source of Salmonella contamination of carcasses. The farm was the most important source of contamination of livers, tongues, rectal samples and mesenterial lymphnodes, for pigs originating from sero-positive herds. The lairage was the most important contamination source for pigs originating from sero-negative herds, for all samples, except carcasses. It is recommended to avoid each direct or indirect contact between different herds along the whole pork production chain, especially between Salmonella-infected and Salmonella-free herds.     

Reduction of Salmonella and fecal contamination of pork during swine slaughter.

Experiments were designed to reduce Salmonella and fecal contamination of pork, using several sanitizing methods and agents. Sanitizing the hauling vehicle and holding pens with chlorine or quaternary ammonium compounds proved ineffective in reducing carcass contamination. When the eviscerator wore a plastic glove and sanitized his knife in 82-C water before using it on each carcass, contamination was reduced about 50%. Sanitizing the eviscerator's knife in 500-ppm chlorine solution adjusted to a pH of 6.0, or in 25-ppm iodine solution reduced contamination approximately 75%.     

HACCP体系与安全猪肉的生产

HACCP是一种保障食品安全的过程控制体系。加拿大、美国、日本等西方发达国家采用HACCP管理体系来生产安全食品,被证明是高度有效的。随着中国加入WTO,加上我国多起肉食品安全事件的接二连三的发生,食品安全已引起社会和政府的高度重视。我国的猪肉产量一直居世界产量的一半以上,但出口量却微乎其微,就其原因,主要还是食品安全存在严重问题。因此,在我国的养猪企业的生产过程中实施HACCP管理体系就显得尤为重要和必要,只有在养猪企业实施HACCP体系,才能从源头上控制危害猪肉食品安全的因素,强化猪肉食品安全生产的链条。养猪企业…     

全球养猪生产:影响猪肉生产业的趋势

最大养猪生产国的数据表明猪群规模的大小是随着养猪生产体系的重建而变化的。     

Monitoring poultry farms for Salmonella by drag-swab sampling and antigen-capture immunoassay

Drag-swab (DS) sampling, at the rate of four DS gauze pads per flock (house); modified culture procedures (novobiocin-supplemented plating media and delayed secondary selective enrichment); and Salmonella antigen-capture (SAC) technology were combined in screening one layer flock and 38 market-age broiler flocks. The results showed that low (negative) SAC sample-to-positive control (S/P) ratios were related to the negative culture recovery of Salmonella. Similarly, high (positive) S/P ratios were related to and indicative of positive culture recoveries. Extensive sampling and testing of 18 of the 39 flocks disclosed A) that five flocks with negative culture recoveries from feathers and freshly voided feces had essentially no positive DS-SAC values, and B) that 13 flocks with positive culture recoveries from feathers and/or fresh feces all had positive DS-SAC values.     

Genetic parameters for carcass composition and pork quality estimated in a commercial production chain

Breeding goals in pigs are subject to change and are directed much more toward retail carcass yield and meat quality because of the high economic value of these traits. The objective of this study was to estimate genetic parameters of growth, carcass, and meat quality traits. Carcass components included ham and loin weights as primal cuts, which were further dissected into boneless subprimal cuts. Meat quality traits included pH, drip loss, purge, firmness, and color and marbling of both ham and loin. Phenotypic measurements were collected on a commercial crossbred pig population (n = 1,855). Genetic parameters were estimated using REML procedures applied to a bivariate animal model. Heritability estimates for carcass traits varied from 0.29 to 0.51, with 0.39 and 0.51 for the boneless subprimals of ham and loin, respectively. Heritability estimates for meat quality traits ranged from 0.08 to 0.28, with low estimates for the water holding capacity traits and higher values for the color traits: Minolta b*(0.14), L* (0.15), a* (0.24), and Japanese color scale (0.25). Heritability estimates differed for marbling of ham (0.14) and loin (0.31). Neither backfat nor ADG was correlated with loin depth (r(g) = 0.0), and their mutual genetic correlation was 0.27. Loin primal was moderately correlated with ham primal (r(g) = 0.31) and more strongly correlated with boneless ham (r(g) = 0.58). Backfat was negatively correlated with (sub)primal cut values. Average daily gain was unfavorably correlated with subprimals and with most meat quality characteristics measured. Genetic correlations among the color measurements and water-holding capacity traits were high (average r(g) = 0.70), except for Minolta a* (average r(g) = 0.17). The estimated genetic parameters indicate that meat quality and valuable cut yields can be improved by genetic selection. The estimated genetic parameters make it possible to predict the response to selection on performance, carcass, and meat quality traits and to design an effective breeding strategy fitting pricing systems based on retail carcass and quality characteristics.     

A cost-benefit analysis of Salmonella-control strategies in Danish pork production

In Denmark, it was agreed to lower the Salmonella prevalence in pork to 1.2% before the end of 2006. The current control did not seem to be sufficient to attain this goal. Therefore, four alternatives to the existing Danish control strategy for Salmonella in pork were compared in a cost-benefit analysis: (1) hot-water decontamination of all pigs at slaughter, (2) sanitary slaughter of pigs from herds with high levels of Salmonella, (3) use of home-mixed feed in herds with slaughter pigs and (4) use of acidified feed for slaughter pigs. The data originated from official statistics, published papers as well as expert opinion. The partial cost-benefit analysis was restricted to slaughterhouses affiliated with the Danish Meat Association and Danish human cases ascribable to pork from these slaughterhouses. Only hot-water decontamination was socio-economically profitable. Hot-water decontamination had a net present value over 15 years of 3.5 million euros. For sanitary slaughter the net present value was - 43.6 million euros, for home-mixed feed it was - 262.3 million euros and for acidified feed it was - 79.9 million euros. For all alternatives the costs were born solely by the pig sector, whereas primarily the consumers and public authorities received the benefits. The conclusions were robust in sensitivity analyses.     

创新生物科技对猪营养和猪肉生产效率改进的推动作用

随着世界人口的不断增长和生活水平的提高,在现有资源不断减少的同时,人们对优质猪肉蛋白质的需求却大幅度增加。除了通过改善日粮的营养水平及组成,还需要依靠生物技术培育出具有优良性状的猪。生物技术可以归类为克隆具有相同遗传组成的动物(通过体细胞核移植,胚胎细胞核移植或胚胎胚吐)或用基因工程(通过重组DNA技术和基因编辑)来产生转基因动物或微生物。克隆有助于保护物种和品种,特别是那些具有良好生物和经济特性的物种和品种。重组DNA技术将来自多个来源的遗传物质结合到单个细胞中以产生蛋白质,并且是基因(基因组)编辑的基础。基因编辑涉及基因的敲除、插入或沉默,以产生具有重要生产性状的转基因猪;或对抗生素敏感的微生物。目前的基因编辑工具包括使用锌指核酸内切酶(ZFN)、类转录激活因子效应物核酸酶(TAL?EN),或基因组定点编辑技术[成簇规律间隔短回文重复-Cas9蛋白(CRISPR/Cas9)]。根据细胞类型和质粒,通过转染(基于脂质的试剂、电穿孔、核转染或显微注射)或噬菌体将ZFN、TALEN或CRISPR/Cas9组分递送到靶细胞中。与ZFN和TALEN编辑相比,CRISPR/Cas9提供更高的效率,更易于设计,以及更高的基因工程灵活性。迄今为止,已经产生转基因猪可以表达牛生长激素、细菌植酸酶、真菌糖酶、植物和秀丽隐杆线虫脂肪酸去饱和酶,以及解偶联蛋白-1;缺乏肌肉生长抑制素,α-1,3-半乳糖基转移酶或CD163[猪生殖和呼吸综合征病毒("蓝耳病")的细胞受体]。生物技术有望在未来能提高猪生产效率和开发抗生素替代品。     

二花脸猪种质资源保护和优质安全猪产品开发

江苏省苏州市乃至全国猪肉产品的质量现状令人担忧 ,主要表现在 :①猪疫病导致其产品有害菌虫污染 ;②猪肉产品中的药物残留超标 ;③猪肉产品中有毒有害物质残留超标。食用猪肉而中毒的事件屡有发生 ,成为危害人体健康的隐形杀手。猪肉产品的卫生安全问题已成为我市“建设最适宜人居和创业的城市”的重要障碍。苏州市地产猪供小于求 ,外地猪源的质量安全令人担心。社会对优质安全猪肉产品的消费需求日益迫切。1　地方品种猪资源现状太湖猪以繁殖性能高和肉质鲜美等优良遗传特性而引起世界养猪界的高度关注。美、法、日等国先后从我国引进了…     

Salmonella in pork cuttings in supermarkets and butchers' shops in Denmark in 2002 and 2006

The prevalence of Salmonella in fresh pork cuttings in Denmark in the years 2002 and 2006 was investigated at retail and compared with the retail supply pattern. A total of 1025 and 3473 samples were taken in 2002 from butcher's shops and supermarkets, respectively. The corresponding numbers in 2006 were 259 from butchers' shops and 628 from supermarkets. In 2002, 1.2% of all samples were positive for Salmonella; butchers' shops and supermarkets had 1.8% and 1.0% positive samples, respectively. The overall prevalence in 2006 was 4.2%, with prevalence of 8.1% and 2.6% for butchers' shops and supermarkets, respectively. Hence, increases around 3- to 5-fold were found. There was neither observed any parallel increase in Salmonella positive carcasses in Danish slaughterhouses during the study period, nor were any changes in supply routes towards slaughterhouses with higher prevalence observed, which could explain the apparent increase. We hypothesize that hygiene levels and ability to avoid cross-contamination and prevent growth of the organism, in the meat processing chain after slaughter were the most likely responsible factors. Results from this study indicate that the hygiene performance, particularly at retail, has a significant impact on the occurrence of Salmonella. This implies that there is no direct link between slaughterhouse Salmonella surveillance data and the level of Salmonella contamination at retail. To improve risk assessment of Salmonella in fresh pork meat, this study underlines the need for comprehensive retail data.