Effect of a single dose of Saccharomyces cerevisiae var. boulardii on the occurrence of porcine neonatal diarrhoea

Piglet neonatal diarrhoea is an important issue in modern pig production and is linked to increased mortality and poor growth rates, affecting long-term pig health, increasing use of medication and cost of production. Saccharomyces cerevisiae var. boulardii (SB) is a probiotic yeast with documented clinical efficacy in the prevention and treatment of diarrhoeal diseases in humans. The objectives of the current study were to evaluate the effect of SB on occurrence and severity of neonatal diarrhoea in piglets, mortality and growth rate. Forty-six litters (606 piglets) were randomly allocated to a control or SB treatment (n=23 per treatment). Within 24 h of farrowing, piglets assigned to the SB treatment received a single oral dose of a paste containing 3.3×109 CFU of SB CNCM I-1079. Piglets from the control litters received a placebo paste. Piglet weight, mortality and diarrhoea were recorded up to day 7 of age. It was shown that numbers of diarrhoea days were significantly correlated with increased mortality rate and reduced weight gain (P<0.05). SB treatment had no effect on growth or mortality in diarrhoeic litters. However, SB-supplemented litters had significantly lower faecal scores, indicating firmer faeces (P<0.01) and fewer numbers of diarrhoeic days (P<0.01) during the 1st week of life. Reduction in the number of diarrhoeic litters compared with the control group was observed following the probiotic administration (P<0.05). These results highlight the detrimental effects of neonatal diarrhoea on pre-weaning performance and suggest that SB, by reducing diarrhoea duration and severity, has the potential of improving enteric health in the early stages of life in pigs

Highly multiplexed quantitative PCR-based platform for evaluation of chicken immune responses

To address the need for sensitive high-throughput assays to analyse avian innate and adaptive immune responses, we developed and validated a highly multiplexed qPCR 96.96 Fluidigm Dynamic Array to analyse the transcription of chicken immune-related genes. This microfluidic system permits the simultaneous analysis of expression of 96 transcripts in 96 samples in 6 nanolitre reactions and the 9,216 reactions are ready for interpretation immediately. A panel of 89 genes was selected from an RNA-seq analysis of the transcriptional response of chicken macrophages, dendritic cells and heterophils to agonists of innate immunity and from published transcriptome data. Assays were confirmed to be highly specific by amplicon sequencing and melting curve analysis and the reverse transcription and preamplification steps were optimised. The array was applied to RNA of various tissues from a commercial line of broiler chickens housed at two different levels of biosecurity. Gut-associated lymphoid tissues, bursa, spleen and peripheral blood leukocytes were isolated and transcript levels for immune-related genes were defined. The results identified blood cells as a potentially reliable indicator of immune responses among all the tissues tested with the highest number of genes significantly differentially transcribed between birds housed under varying biosecurity levels. Conventional qPCR analysis of three differentially transcribed genes confirmed the results from the multiplex qPCR array. A highly multiplexed qPCR-based platform for evaluation of chicken immune responses has been optimised and validated using samples from commercial chickens. Apart from applications in selective breeding programmes, the array could be used to analyse the complex interplay between the avian immune system and pathogens by including pathogen-specific probes, to screen vaccine responses, and as a predictive tool for immune robustness

Binding of a cellular factor to the 3 ' untranslated region of the RNA genomes of entero- and rhinoviruses plays a role in virus replication

The presence of cellular factors that bind to the 3' untranslated region (UTR) of picornaviruses was investigated by electrophoretic mobility shift assays (EMSAs). A cellular factor(s) that binds specifically the 3' UTR of polio-, coxsackie-and rhinoviruses was detected. Furthermore, this factor(s) is distinct from those which bind to the 5' terminal 88 nt (the 'cloverleaf') of poliovirus. Mutations within the 3' UTR which decrease the affinity of the RNA for the cellular factor in EMSAs decrease RNA replication and virus viability. Revertants of these mutants display changes which are predicted to stabilize the RNA secondary structure of the 3' UTR. These results indicate that binding of a cellular factor to the UTR plays a role in virus replication and that RNA secondary structure is important for this function.</p

Viabilité et quantification d'une levure probiotique dans le système digestif du porc

Viability and colonisation of a probiotic yeast in the digestive tract of piglets Probiotics have been defined as « live microorganisms which when administered in adequate amounts confer a health benefit on the host» (WHO, 2001). This definition implies that viability is an important factor and that the probiotic needs to reach its target site alive and in significant number in order to confer beneficial properties. Therefore, we investigated the survival and the level of the probiotic yeast Saccharomyces cerevisiae CNCM I-1079 (SB) along the gut of pigs and in faeces. For this purpose, 3 piglets from SB supplemented sows were orally dosed with SB for a week before sacrifice at 21 days of age. Faecal samples were collected as well as intestinal tract compartment content for yeast count and characterization. We have used advanced techniques to be able to identify and enumerate accurately SB from other yeasts according to morphology and biomolecular profile criteria. We have demonstrated that SB remains viable and in proportionally high number along the gut of pigs and in faeces, suggesting that both sites of main actions for probiotics (small intestine and hindgut) can benefit from the presence of live yeast cells at a biologically significant level

A regulator gene for acetate utilisation from Neurospora crassa.

The Neurospora crassa homologue of the Aspergillus nidulans regulatory gene facB has been cloned. The gene encodes a putative transcriptional activator of 865 amino acids that contains a DNA-binding domain with a Zn(II)(2)Cys(6) binuclear cluster, a linker region and a leucine zipper-like heptad repeat. Two internal amino acid sequences are identical to peptide sequences determined from proteolytic fragments of a DNA-binding protein complex specific for genes involved in acetate utilisation and expressed in acetate-induced mycelia of N. crassa. Recombinant expression of the predicted DNA-binding domain demonstrates that it is capable of independent recognition of a subset of the promoter sequences that bind the protein complex from N. crassa. A duplication-induced mutation in the corresponding gene results in an acetate non-utilising phenotype that is characterised by inefficient induction of the enzymes required for acetate utilisation. The new gene does not fall into any existing complementation group and has been designated acu-15

Influence du sevrage et de l’addition de levures vivantes sur la population bactérienne fécale chez le porcelet

Influence of weaning and live yeast on faecal bacteria populations in pigs The current studies describe how the diversity of faecal bacteria is affected by weaning and incorporation of live yeast into the post-weaning diet of pigs. Pigs were weaned at 28 days of age onto an experimental weaner diet with or without Saccharomyces cerevisiae boulardii CNCM I-1079 (4 x 106 CFU/g in feed, plus an extra dose of 3 x 109 CFU delivered through oral drenching). A longitudinal analysis was performed, collecting faecal samples of the same individual pigs pre-weaning and at + 4 and + 11 days post-weaning. Culture-based and next generation sequencing (16S rDNA) approaches were used to describe the diversity and composition of the faecal bacterial community. We observed that a different and characteristic bacterial diversity depicts the faecal bacteria microbiota of individual pigs at weaning and after both 4 and 11 days post-weaning. In addition, our results show a difference in bacterial diversity and community structure between pigs fed live yeast versus control and that this difference may be attributable to changes in the composition of low abundance taxa. The specific changes on microbiota induced by adding live yeast to pig diets will then be investigated