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Food preservation is a vital issue on a global scale. It reflects both the need to prevent food spoilage as well as the necessity for reduction in the occurrence of food-borne pathogens. Progress of technology allowed for the development of various techniques that inhibit the growth or activity of food contaminating microbes. In the last few years we saw creation of various types of antimicrobial food packaging systems. They contain active antimicrobial agents immobilized on a material that acts as a food wrap. In this paper we have tested the efficiency of Abeego, a commercially available food wrap, against representatives of different groups of microbes. The Abeego wrap contains natural products such as waxes and oils, which can display antimicrobial activity. We analyzed the ability of the wrap and its components to affect the growth and replication of various groups of microorganisms. We have discovered that the Abeego wrap was capable of significantly inhibiting the viable cell count of bacterial species - both gram positive and gram negative. However no noticeable antifungal or antiviral activity has been observed. This implies that Abeego wrap can act as an efficient mean of inhibiting the spread of food-borne bacterial pathogens, as well as contribute to preventing food spoilage. [ABSTRACT FROM AUTHOR]

A synthetic version of the ligA gene encoding the NAD-dependent DNA ligase from the Arctic bacterium Pseudoalteromonas haloplanktis was substituted for its homolog in the chromosome of Mycobacterium smegmatis. The resulting recombinant strain grew identically to the parent strain at permissive temperatures but failed to grow above 37°C. The temperature-sensitive phenotype was stable, and the strain failed to generate temperature-resistant forms at a detectable level. Repeated passage of the hybrid strain resulted in no changes in the psychrophilic ligA gene. Given the high identity of the DNA ligases among mycobacterial species, these results suggest that a stable temperature-sensitive strain of M. tuberculosis could be generated using the approach described here. [ABSTRACT FROM AUTHOR]

The shape and volume of microglia (brain immune cells) change when they activate during brain inflammation and become migratory and phagocytic. Swollen rat microglia express a large Cl– current (IClswell), whose biophysical properties and functional roles are poorly understood and whose molecular identity is unknown. We constructed a fingerprint of useful biophysical properties for comparison with IClswell in other cell types and with cloned Cl– channels. The microglial IClswell was rapidly activated by cell swelling but not by voltage, and showed no time-dependence during voltage-clamp steps. Like IClswell in many cell types, the halide selectivity sequence was I– > Br– > Cl– > F–. However, it differed in lacking inactivation, even at +100 mV with high extracellular Mg2+, and in having a much lower single-channel conductance: 1–3 pS. Based on these fundamental differences, the microglia channel is apparently a different gene product than the more common intermediate-conductance IClswell. Microglia express several candidate genes, with relative mRNA expression levels of: CLIC1 > ClC3 > ICln ≥ ClC2 > Best2 > Best1 ≥ Best3 > Best4. Using a pharmacological toolbox, we show that all drugs that reduced the microglia current (NPPB, IAA-94, flufenamic acid and DIOA) increased the resting cell volume in isotonic solution and inhibited the regulatory volume decrease that followed cell swelling in hypotonic solution. Both channel blockers tested (NPPB and flufenamic acid) dose-dependently inhibited microglia phagocytosis of E. coli bacteria. Because IClswell is involved in microglia functions that involve shape and volume changes, it is potentially important for controlling their ability to migrate to damage sites and phagocytose dead cells and debris. [ABSTRACT FROM AUTHOR]