A rapid, inexpensive and effective method for the efficient isolation of genomic DNA from Gram-negative bacteria.

Currently, there are several protocols to extract bacterial DNA based on different principles. However, the quantity and the quality of the DNA obtained by each method are highly variable and microorganism dependent. In most of these classical crude methods, highly toxic and hazardous organic solvents such as phenol and chloroform are used for deproteinization, whereas in certain protocols, expensive enzymes including RNases and Proteinases are used. This study was designed to introduce a simple, rapid, inexpensive and effective genomic DNA isolation procedure for Gram-negative bacteria, without the usage of toxic chemicals and costly enzymes. This novel method was compared with another classical method known as the salting-out method, which uses proteinase-K. Concentration and yield of the extracted DNA were determined by gel electrophoresis by comparing the gel band intensity of the sample DNA to that of a DNA quantitation standard and by the Quantus™ fluorometer. According to the results, the yield of extracted DNA was higher in the novel method compared to the salting-out method. Moreover, the entire process was accomplished in less than 2 h with the novel method. Purity and integrity of extracted genomic DNA by both methods were similar. In addition, the quality of DNA was determined using Multicopy Associated Filamentation (MAF) gene amplification by polymerase chain reaction (PCR). Thus, the described technique is non-toxic, less time and fund consuming, efficient and a well-suited method for routine DNA isolation from Gram negative bacteria.

The role of bacterial toxins and spores in cancer therapy.

Cancer is one of the leading causes of human death worldwide. Conventional anticancer therapies are ineffective in treating cancer patients due to various reasons. Thus, more effective and accessible alternative anticancer strategies have been evolved with time with high specificity towards tumor cells and with less or no adverse effects to normal cells. One such promising therapy is the use of bacterial toxins and spores to treat advanced solid tumors. Initially, Coley paved the way towards the bacterial anticancer therapy several decades ago and now it has emerged as a potential tool to eliminate tumor cells. Bacterial spores of obligate anaerobes exclusively germinate in the hypoxic/necrotic areas and not in the well-oxygenated areas of the body. This unique phenomenon has been exploited in using bacterial spores as a remedy for cancer. Bacterial toxins also play a significant role in either directly killing tumor cells or altering the cellular processes of the tumor cells which ultimately leads to the inhibition and regression of the solid tumor. With the advancement of molecular techniques, a number of genetically-modified non-pathogenic bacteria have been developed to use in bacterial anticancer strategies. Although promising results have shown so far, further investigations are required to ensure the efficacy and the safety of the bacterial spores and toxins in treating cancer.