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The study aimed to determine in growing pigs the effect of 2 dietary protein sources and 2 calcium-phosphorus (CaP) levels on gut microbiota composition, microbial metabolic activity and on the intestinal immune system. Thirty-one pigs were fed corn-soybean meal (SBM) or corn-pea meal (PM)- based diets supplemented with CaP 20% below (CaP- ) or above (CaP+) the animals' Ca and P requirement. Cell numbers of total bacteria, Enterobacteriaceae, and Bacteroides-Prevotella-Porphyromonas in the jejunum, cecum, and colon and cecal ammonia concentration were determined. Lymphocytes (LC) from jejunal and ileal mesenteric lymph nodes (MLN) were examined for mitogen-induced proliferative response against concanavalin A (ConA). The CaPdiets resulted in higher jejunal gene copy numbers of total bacteria (P < 0.01), and tended to increase jejunal, cecal, and colonic gene copy numbers of Bacteroides-Prevotella-Porphyromonas (P < 0.10) compared to CaP+ diets. For the PM diets, intestinal Enterobacteriaceae were higher (P < 0.05), whereas cecal ammonia concentration was lower (P < 0.01) compared to the SBM diets. There was a tendency (P < 0.10) for higher proliferation to ConA for CaP-diets in MLN LC compared to CaP+ diets. An increase in abundance of Enterobacteriaceae for the PM diet in association with low dietary CaP content might increase the risk for intestinal disturbances and the lower cecal ammonia concentration for the PM diets may be beneficial for gut health. [ABSTRACT FROM AUTHOR]

Aims: In order to improve the diagnosis of Bacillus anthracis in environmental samples, we established a DNA microarray based on the ArrayTube technology of Clondiag. Methods and Results: Total DNA of a bacterial colony is randomly biotinylated and hybridized to the array. The probes on the array target the virulence genes, the genomic marker gene rpoB, as well as the selective 16S rDNA sequence regions of B. anthracis, of the Bacillus cereus group and of Bacillus subtilis. Eight B. anthracis reference strains were tested and correctly identified. Among the analysed environmental Bacillus isolates, no virulent B. anthracis strain was detected. Conclusions: This array clearly differentiates B. anthracis from members of the B. cereus group and other Bacillus species in environmental samples by chromosomal ( rpoB) and plasmid markers. Additionally, recognition of B. cereus strains harbouring the toxin genes or atypical B. anthracis strains that have lost the virulence plasmids is feasible. Significance and Impact of the Study: The array is applicable to the complex diagnostics for B. anthracis detection in environmental samples. Because of low costs, high security and easy handling, the microarray is applicable to routine diagnostics. [ABSTRACT FROM AUTHOR]