Early-life dietary spray-dried plasma influences immunological and intestinal injury responses to later-life Salmonella typhimurium challenge.

Increasing evidence supports the concept that early-life environmental influences, including nutrition and stress, have an impact on long-term health outcomes and disease susceptibility. The objective of the present study was to determine whether dietary spray-dried plasma (SDP), fed during the first 2 weeks post-weaning (PW), influences subsequent immunological and intestinal injury responses to Salmonella typhimurium challenge. A total of thirty-two piglets (age 16-17 d) were weaned onto nursery diets containing 0, 2·5 % SDP (fed for 7 d PW) or 5 % SDP (fed for 14 d PW), and were then fed control diets (without SDP), for the remainder of the experiment. At 34 d PW (age 50 d), pigs were challenged with 3 × 109 colony-forming units of S. typhimurium. A control group (non-challenged) that was fed 0 % SDP in the nursery was included. At 2 d post-challenge, the distal ileum was harvested for the measurement of inflammatory, histological and intestinal physiological parameters. S. typhimurium challenge induced elevated ileal histological scores, myeloperoxidase (MPO), IL-8 and TNF, and increased intestinal permeability (indicated by reduced transepithelial voltage (potential difference) and elevated 4 kDa fluorescein isothiocyanate dextran (FD4) flux rates). Compared with S. typhimurium-challenged controls (0 % SDP), pigs fed the 5 % SDP-14 d diet exhibited reduced ileal histological scores, MPO levels, IL-8 levels and FD4 flux rates. Pigs fed the 5 % SDP-14 d nursery diet exhibited increased levels of plasma and ileal TNF-α in response to the challenge, compared with the other treatments. These results indicate that inclusion of SDP in PW diets can have an influence on subsequent immunological and intestinal injury responses induced by later-life S. typhimurium challenge.

Farm and environmental distribution of Campylobacter and Salmonella in broiler flocks.

The objective of this study was to determine the prevalence of Campylobacter and Salmonella in broilers and their distribution in the indoor and outdoor farm environment. Nine hundred samples (400 faecal; 300 indoor environment; 200 outdoor environment), were collected from 10 individual broiler houses on 10 farms. Campylobacter jejuni prevalence was significantly higher (P=0.003) in faeces (29.5%; 118/400) than the environment (0.8%; 4/500) in contrast to Salmonella Typhimurium from faecal (8.8%; 35/400) and environmental (8.4%; n=42/500) sources (P=0.217). S. Typhimurium predominantly exhibited antimicrobial resistance (AR) to streptomycin (46%) and tetracycline (31.5%). C. jejuni isolates exhibited AR only to tetracycline (55.5%). The PFGE profile revealed 100% similarity between S. Typhimurium isolates from faecal and environmental sources. No relationship was detected between C. jejuni isolates. The low prevalence of Campylobacter and Salmonella in the outdoor environment indicates that it may not be a significant reservoir for transmission of these pathogens on broiler farms.

Longitudinal study comparing the dynamics of Clostridium difficile in conventional and antimicrobial free pigs at farm and slaughter.

Clostridium difficile is the leading cause of nosocomial diarrhea in humans and a major cause of enteritis in neonatal piglets, foals and calves. The aim of this longitudinal study was to determine and compare the prevalence, antimicrobial susceptibility, and toxinotype profiles of C. difficile isolated from pigs and their environment in the indoor conventional and outdoor antimicrobial free (ABF) production systems. Ten conventional and eight ABF cohorts of 35 pigs each and their environment were sampled at different stages of production at farm and slaughter. C. difficile prevalence in pigs was highest at the farrowing stage in both conventional (34%, 120/350) and ABF (23%, 56/244) systems, and decreased with age. This reduction in C. difficile prevalence in pigs at later stages of production mirrored the decreased prevalence in the farm environment. At slaughter, C. difficile was isolated at a low frequency from the carcasses and processing environment in both production systems. All but three isolates were resistant to ciprofloxacin (99%, 505/508), while 1.0% (5/508) and 6.0% (23/508) of isolates exhibited resistance to tetracycline and erythromycin, respectively. Toxinotype V (tcdA(+)tcdB(+)) was the predominant strain identified in both systems (conventional: 94%, 376/401; ABF: 82%, 88/107), while the rest were toxinotype XIII (tcdA(+)tcdB(+)). To conclude, we isolated antimicrobial resistant C. difficile regardless of antimicrobial use on the farm. Based on the phenotypic and genotypic similarity of C. difficile isolated in this study, we conclude that the unique production practices employed in conventional and ABF production systems have no impact on the pathogen population.