| Autor: |
Morrison, Dennis, Milanovich, Fred, Ivnitski, Dmitri, Austin, Thomas R., Ignatov, O. V., Guliy, O. I., Bunin, V. D., Voloshin, A. G., O’neil, D., Ivnitski, D. |
| Zdroj: |
Defense Against Bioterror; 2005, p147-163, 17p |
| Abstrakt: |
An electro-optical approach has been used for studies of microbial cells and some biological agents (antibodies and phages) binding. The electro-optical analyzer (ELUS EO), which has been developed at the State Research Center for Applied Microbiology, Obolensk, Russia, was used as the basic instrument for electro-optical measurements. Since the AC electrokinetic effects depend on dielectric properties of bioparticles, their composition, morphology, phenotype, the medium, and the frequency of applied electrical field, the electro-orientational spectra were used for discrimination of bacteria before and after selective binding with antibodies. It has been shown in the model systems that the biospecific interactions of Listeria monocytogenes cells as target cells with anti-Listeria antibody in the presence of E. coli K-12, and A. brasilense Sp7 change the electro-optical signals significantly. Thus, the determination of the presence of particular bacteria within a mixed sample may be achieved by selection and matching of antibodies specific to individual bacterium types and by comparing spectra of bacterium in the presence and in the absence of specific antibodies. The same principles were used for the investigations of bacteria — phage interactions. Biospecific binding was used between Escherichia coli XL-1 cells and the phage M13K07. The phage-cell interaction includes the following stages: phage adsorption on the cell surface, entry of viral DNA into the bacterial cell, amplification of phage within infected host and phage ejection from the cell. In this work, we used M13K07, a filamentous phage of the family Inoviridae. Preliminary study had shown that combination of the EO-approach with a phage as a recognition element has an excellent potential for mediator-less detection of phage-bacteria complex formation. The interaction of E. coli with phage M13K07 induces a strong and specific electro-optical signal as a result of substantial changes of the EO properties of the E. coli XL-1 suspension infected by the phage M13K07. Integration of the electro-optical approach with a phage has the following advantages: 1) bacteria from biological samples need not be purified, 2) the infection of phage to bacteria is specific, 3) exogenous substrates and mediators are not required for detection, and 4) it is suitable for any phage-bacterium system when bacteria-specific phages are available. [ABSTRACT FROM AUTHOR] |
| Databáze: |
Supplemental Index |
| Externí odkaz: |
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