Vector-mediated chromosomal integration of the glutamate decarboxylase gene in Streptococcus thermophilus.
Authors: Renye JA, Somkuti GA Abstract The integrative vector, pINTRS, was used to transfer glutamate decarboxylase (GAD) activity to Streptococcus thermophilus ST128 thereby allowing for the production of γ-aminobutyric acid (GABA). In pINTRS, the gene encoding glutamate decarboxylase, gadB, was flanked by DNA fragments homologous to a S. thermophilus pseudogene to allow for integration at a non-essential locus on the chromosome. Screening techniques confirmed the insertion of gadB with either its endogenous promoter or the S. thermophilus P2201 promoter, resulting in the generation of recombinant strains, ST128/gadB or ST128/P2201-gadB. Following the integration event unwanted plasmid DNA, specifically the erythromycin resistance gene, was eliminated from the recombinant strains...

A Longitudinal Study on Persistence of Antimicrobial Resistant Campylobacter in Distinct Swine Production Systems at Farm, Slaughter and Environment.
The objectives of this study were to compare and characterize the prevalence of antimicrobial resistant (AR) Campylobacter in the conventional and the antimicrobial-free (ABF) production systems at farm, slaughter and environment. Fecal and environmental samples were collected from ABF (pigs: 1239; environment: 797) and conventional farms (pigs: 1650; environment: 1325). At slaughter, we collected samples from carcasses including post-evisceration swabs, post-chill swabs and mesenteric lymph nodes from ABF (post-evisceration swabs: 182; post-chill swabs: 199; mesenteric lymph nodes: 184) and conventional (post-evisceration swabs: 272; post-chill swabs: 271; mesenteric lymph nodes: 255) systems at separate processing facilities. We also sampled the processing plant environment including tru...