Serological research of Salmonella on Belgian pig farms

Risk factors for Salmonellosis in pigs were investigated in a cross-sectional study on 144 Belgian farrow-to-finish herds belonging to one slaughterhouse co-operation. Herd data were collected using a questionnaire. The blood samples were serologically analyzed. Variables significantly related to the Salmonella prevalence in the univariate analyses were subsequently analysed in a multivariate model. Furthermore, the clustering of Salmonella infection within the herd, section and pen was studied. The average within-herd seroprevalence was: 73.4% when using OD 10%. In the multivariate analyses the structure of the feed seems to be the most important factor of the model with five factors. Feeding pigs meal instead of granulated or crumb is a protecting factor for Salmonella. Other risk factors in the multivariate model are natural ventilation, less then 3 days emptiness after wet cleansing, not dry cleansing of sows’ pen before wet cleansing and the absence of dogs in the pig houses

Correlation between bacteriology of lymph nodes and serology for Salmonella diagnosis in slaughter pigs

Salmonella control programs in pigs are usually based on serological tests. The major objective of this cross-sectional study was to investigate the correlation between the serological results and the bacteriological results of Salmonella diagnosis in pigs at the herd level and at the animal level. From 60 farrow-to-finish herds, serum samples and mesenterial lymph nodes from 30 fattening pigs were taken in the slaughterhouse

The Belgian Salmonella surveillance programme 2005

The Belgian Salmonella Surveillance Programme on pig farms, organized by the Federal Agency for the Safety of the Food Chain, started in January 2005. The programme is built up in several stages. In the first stage the 10 % farms with the highest seroprevalence (number of positive samples per farm) are identified

Transmission of Salmonella from sows to piglets: a longitudinal study

The study objective was to investigate the probability of transmission of Salmonella from sows to their offspring. In each of 3 farrow-to-finish herds (A, B, and C), one cohort of sows (n=34, n=40, n=32, respectively), together with 3 piglets of their offspring (n=102, n=120, n=96, respectively) were selected

Dynamics of subclinical Salmonella infections in farrow-to-finish pig herds

The study objective was to investigate patterns of Salmonella shedding in finishing pigs. In each of 3 farrow-to-finish herds (A, B, and C), one cohort of fattening pigs (n=102, n=120, n=96, respectively) was selected

Antimicrobial resistance in Salmonella strains from fattening pigs and sows

The prevalence of antibiotic resistance and of different resistance patterns for Salmonella isolates collected from sows, from fattening pigs at different ages and at slaughter was determined

Quantification of the spread of Salmonella and the effect of 2 feed additives

The aim of this experiment was to quantify the spread of Salmonella Typhimurium in weaned piglets by calculating R0 values. In addition, the effect of 2 feed additives, AROMABIOTIC“ and Shiitake mushroom, on the spread of Salmonella Typhimurium was evaluated. Fifty-nine piglets were allocated to 4 groups: AROMABIOTIC“ (A, n=16), Shiitake mushroom (B, n=16), positive (C, n=16) and negative controls (D, n=11). Half of the piglets of group A, B and C were experimentally inoculated with Salmonella Typhimurium, other piglets were used as susceptibles. Based on Salmonella isolation in faecal swabs, R0 values (95% C.I.) were 4.26 (1.40-34.69), 1.83 (0.86-9.38) and 4.29 (1.09-13.71) for group A, B and C, respectively. None of the measured parameters did indicate significant differences between the groups. Mortality rate was high in all 4 groups, what makes it necessary to repeat the experiment

Effect of the use of organic acids in drinking water during the last two weeks prior to slaughter on salmonella shedding

In this study we investigated the effect of adding organic acids to the drinking water of finishing pigs two weeks prior to slaughter on the shedding and prevalence rate of Salmonella at slaughter. One hundred animals from 4 Belgian pig herds infected with Salmonella were included. Fifty of these ammals received drinking water supplemented with a mixture of different organic acids during 14 days prior to slaughter. Non-treated animals served as controls. Different samples were taken: contents of ileum and rectum, mesenteric lymph nodes and carcass swabs. All samples were submitted to Salmonella isolation using standard procedures. The results could not reveal a significant difference between both groups. This may be due to the limited power of the study (only 50 animals sampled in each group) or due to the fact that the treatment duration was insufficient to prove the benefit of the used organic acids

Evaluation of different enrichment media for the isolation of Salmonella spp from faeces and lymph nodes in slaughter pigs

The aim of the study was to compare the isolation results of Salmonella spp. from faeces and mesenterial lymph nodes on 2 semi-solid media and 2 broths. For the faeces samples, Modified Semi-solid Rappaport Vassiliadis (MSRV) seemed to be the medium with the highest sensitivity. For the lymph node tissue samples, there was no significant difference between the different media. In parallel testing, for both types of sample a combination of RV or IT with MSRV seemed to be the best although differences were small. The use of such a combination is important because of the possible differences in motility characteristics among different Salmonella serotypes. Another goal was the evaluation of different sizes of sample material. To increase the sensitivity, it is important to use enough sample material. There was a significant difference regarding the number of positives in lymph node samples and in faeces samples, so not every carrier animal appeared to shed Salmonella or vice versa