Bacterial plasmid: A study of its role in resistance to some antibiotics and natural substances

Plasmids have a function to regulate the activity of the enzymes involved in the catabolic (synthesis) pathway of antibiotics. This study aimed to examine the effects of high temperature on the amount that local isolates of E. coli 1 and 2, Klebsiella and Bacillus retain their plasmids. Bacteria were isolated and identified using two types of media: MacConkey and nutrient agar and also Gram stain. The genetic loci responsible for the development of an isolate's resistance to antibiotics were identified using a diffraction test. By employing the diffusion discs method, it is possible to determine the susceptibility of bacteria to multiple antibiotics. The results revealed that the responses of the different original isolates to antibiotics, extracts and some compounds varied. Likewise, there was a difference in the response of the isolates exposed to heat in comparison to the original, with the local isolate E. coli 1 exposed to heat showing antibiotic sensitivity (KF, RA, DO, CN, GTX). In conclusion, the original isolate was not susceptible to antibiotics used or natural materials (Lawson plant extract, Adhatoda vasica and tabacum) due to the loss of the plasmid responsible for this isolate's resistance to those materials.