Genome Sequencing Blanks For Antibiotic Discovery

The U.S. Department of Energy Joint Genome Institute (DOE JGI) has recently conducted a systematic analysis from public databases on the substantial backlog of microbial genome sequences. Their recent study led to the identification of genes that kill bacteria, which are used in the sequencing process. As such, this may result to the formation of new strategies in approaching discoveries for new antibiotics.

In nature, a myriad of microbes have the same genetic information. As such, the use of genes to readily identify the species of such microbes and their places in evolution were thought to be pointless. Now, however, the DOE JGI researchers have distinguished barriers to this gene transfer. The process starts with the identification of genes that destroys the recipient bacterium upon transfer, not considering the type of bacterial donor. Such lethal genes also impart better reference points for the construction of phylogenic trees, which are the means of substantiating evolutionary relationships between organisms.

DOE JGI Director, Eddy Rubin, said that the organization is responsible for the production of genomes from various microbes and making the available to the public. The said microbial sources are relevant in the advancement in the fields of bio-energy, carbon recycling, and bioremediation. Furthermore, Rubin also stated that sequencing a genome is akin to the conduction of a colossal experiment in gene transfer. However, as their studies progressed, they have found barriers to gene transfers by examining genes that could not be sequenced.

In order to conduct DNA sequencing in the industrial scale, the DNA of an organism is sheered into manageable fragments. Then, such fragments are inserted into a disarmed E. coli strain. These are used in order to enrich the culture or to speed up the growth to vast amounts of the DNA target. The DOE JGI was able to find out that such process of DNA sequencing copies the transmission of DNA from one organism to another. This process is called, horizontal gene transfer. This phenomenon occurs naturally. As such, the process enables one organism to get hold of genes and use such genes from other organisms. However, this is an extremely process is rare in animals. In contrast, such process happens frequently in microorganisms. As such, the said process is one of the main sources for the quick spread of resistance to antibiotics among bacteria.

In the observation of bacteria behavior, a simple piece of equipment that can assist a researcher is the brightfield light microscope. A brightfield light microscope lights up the bacterium specimen sample by using transmitted white light, which is the illumination that comes from below and observed from above. A good brightfield light microscope is operational with an adjustable condenser that has an aperture diaphragm or contrast control aside from its built-in illuminator. Apart from those, the other parts of the brightfield light microscope include the mechanical stage and the binocular eyepiece tube. Among the significant advantages of using a brightfield light microscope for research are the simplicity of the technique and the minimal sample preparation.