Prevalence of subclinical Salmonella enterica infection in Danish finishing pig herds.
ABSTRACT Our aim was to determine the Salmonella enterica prevalence in 96 randomly selected Danish pig herds, based on serological examination of blood samples and bacteriological examination of faecal samples (collected simultaneously from the same pens). For comparison, 39 high-seroprevalence herds were included in the study. The representativeness of the selected herds was assessed, based on descriptive statistics of herd size and type. Totals of 1330 pen samples and 6814 blood samples were examined.The results from the meat-juice screening in the Danish S. enterica Control Programme were available for 3372 meat-juice samples from 91 of the 96 randomly selected herds and 1195 meat-juice samples from 37 of the 39 high-seroprevalence herds. Of the 96 randomly selected herds, 23 herds had no positive pen samples (out of 10), no positive blood samples (out of 50) and no positive meat-juice samples (out of approximately 30-40 samples in 6 months). Ten herds had one or more positive meat-juice samples but were otherwise negative. S. Typhimurium was isolated from 30 of the 39 high-seroprevalence herds. Our conclusions were: (1) The within-herd seroprevalence among the 96 randomly selected Danish pig herds was low (average within-herd seroprevalence=2%, maximum=32%). (2) Among the 39 high-seroprevalence herds (recently assigned level 3 in the S. enterica Control Programme), S. enterica was isolated from 77% of the herds when 10 pen samples were examined bacteriologically. (3) Seropositivity tended to be related to the presence of S. Typhimurium.
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ABSTRACT: The association between Salmonella sp. isolated from the intestinal tract of pigs at slaughter and its presence in tonsils/mandibular lymph nodes (T/MDL) used in the sausage manufacture was assessed. In a trial mesenteric lymph nodes (LM), intestinal contents (IC) and T/MDL were collected from 90 animals. Salmonella sp. was isolated from 71 (79%) animals in at least one of the samples. T/MDL contaminated samples were correlated with Salmonella sp. isolated from LM and/or IC (P<0.001), with odds ratioLTpositive 5.6. In other trial, T/MDL of 75 animals processed separately, were associated with isolation of Salmonella sp (P< 0.0001). The serovars more prevalent were Typhimurium and Bredeney. It was concluded that Salmonella sp. presence in the intestinal tract is a risk factor for contamination of the portions of carcasses used in sausage manufacture.Arquivo Brasileiro de Medicina Veterinária e Zootecnia 06/2004; 56(3):300-306. · 0.20 Impact Factor
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ABSTRACT: To examine patterns of Salmonella herd infections in units linked by common sources of pigs, the study examined pooled pen faeces samples from 161 nursery and finishing units in a UK integrated pig enterprise. An epidemiological questionnaire was also completed by investigators for each farm. Salmonella was isolated from 630 (19.5%) of the samples: S. Typhimurium was found in 387 (12%) and S. Derby in 157 (4.9%) samples; 111 units yielded at least one sample containing Salmonella. The proportion of Salmonella-positive samples from positive farms ranged from 5% to 95%. In a univariable risk factor analysis, increasing length of time as a pig farm was positively associated with the detection of Salmonella in a herd. Larger farms (>500 pigs) were significantly more likely to be positive for S. Typhimurium than smaller farms. There was an association between Salmonella serovars isolated in the present study and those subsequently isolated in breeding herds linked to the integration.ISRN veterinary science. 12/2013; 2013:943126.
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ABSTRACT: The aim of this study was to determine the prevalence and infection status of Salmonella species (spp.) in 25 conventional pig farms by traditional fecal culture and serological methods to develop a Salmonella control program for Korean pig farms. The individual seroprevalence of Salmonella spp. in pigs reared in the 25 pig farms was 83.1% in sows and 6.4-32% in different aged pig groups, with the total seroprevalence 28.4% (141/848). The seroprevalence of the tested pigs increased in accordance with the decrease in maternal antibody and the rearing period on these farms. Of note, all the 25 pig farms contained at least two or more anti-Salmonella antibody-positive sows. In the fecal cultures Salmonella spp. were isolated only in three (12.0%, 3/25) of 16 serologically Salmonella-suspected farms (64.0%, 16/25), showing the limitation of the fecal culture method and the need for serum assays to understand the exact status of Salmonella infection in swine herds, which likely contain subclinically infected pigs or carriers. The results highlight the need to establish a supply system of Salmonella-free gilts for the promotion of a national Salmonella control program on swine farms in Korea. Further studies will be needed to develop an effective monitoring system for the implementation of a national Salmonella control program.Journal of Life Science. 10/2013; 23(10).