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Mark Bailey

Publications and source records attributed to Mark Bailey.

5 recordsLinked to original sources
PubMed2005

Studying plasmid horizontal transfer in situ: a critical review.

This review deals with the prospective, experimental documentation of horizontal gene transfer (HGT) and its role in real-time, local adaptation. We have focused on plasmids and their function as an accessory and/or adaptive gene pool. Studies of the extent of HGT in natural environments have identified certain hot spots, and many of these involve biofilms. Biofilms are uniquely suited for HGT, as they sustain high bacterial density and metabolic activity, even in the harshest environments. Single-cell detection of donor, recipient and transconjugant bacteria in various natural environments, combined with individual-based mathematical models, has provided a new platform for HGT studies.

Bacteria↗
PubMed2005

Normal-flow virus filtration: detection and assessment of the endpoint in bio-processing.

The breakthrough of a model virus, bacteriophage PhiX-174, through normal-flow virus filters was studied using both commercial process fluids and model feed streams. The results indicate that (i) PhiX-174 is a reasonable model for a mammalian parvovirus [MMV (murine minute virus)] in virus filtration studies; (ii) PhiX-174 LRV [log(reduction value)] shows a better correlation with percentage flow decline compared with volume processed under a variety of conditions; (iii) although the extent of decline in virus LRV is dependent on the mechanism of filter fouling, the fouling mechanisms operative in a viral validation study are representative of those likely to be found under actual production conditions. The mechanism of LRV decline by many process streams was proposed to be due to selective plugging of small pores. A theoretical model as well as a predictive equation for LRV decline versus flow decay was derived; experimental results from filtration studies using pore-plugging feed stocks were consistent with the equation. As protein solutions may vary in their adsorptive versus plugging behaviour during filtration, an evaluation of the LRV-versus-flow-decay relationship on a biopharmaceutical-product-specific basis may be warranted.

Animals↗