Publication details
Antibacterial methods based on bioluminescent bacteria
| Authors | |
|---|---|
| Year of publication | 2011 |
| Type | Conference abstract |
| MU Faculty or unit | |
| Citation | |
| Description | Bioluminescent bacteria are common in salt water environment, but there is the only one genus of soil bacteria with natural bioluminescence – Photorhabdus sp. These symbiotic bacteria reside the gut of entomopathogenic nematodes which are obligate insect parasites with the increasing importance as biological control agent. Isolated Photorhabdus luminescens was used separately for determination of pathogenity to insects. Except P. luminescens the artificial bioluminescent bacterium was used - genetically modified Escherichia coli K12 that carries Photorhabdus genes for bioluminescence. Both of these G- bacteria can be used for antibacterial assays based on their bioluminescence ability. Bioluminescence reaction is mediated by bacterial enzyme luciferase which catalyses the oxidation of long-chain aldehyde (substrate) and reduces flavin mononucleotide with emission of light. This emission can be immediately measured by the luminometer. Bioluminesence is directly connected to kinetics of bacterial growth (the more living bacteria the higher luminescence signal). Immune systems of both vertebrates and invertebrates content number of antibacterial peptides; moreover cooperating with complement cascade and myeloperoxidase activity in vertebrates. After addition of sample (e. g. insect hemolymph, vertebrate blood, plasma or serum) we observed decreasing viability of bacteria. The time required for 50% viability of bacteria was evaluated using kinetic curves corresponding to antibacterial activity of samples. Using different conditions of bioluminescence assay and inhibitors of particular immune effectors, we optimised assay for antibacterial activity measurements of specific parts of immune system both in vertebrates and invertebrates. Our research is supported by grant from Grant Agency of Czech Republic (GA206/09/P470). |
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