Analysis of the effects of horizontal gene transfer on bacteriophage infectivity

Abstract

Bacterial infections and their treatment have been a longstanding interest for researchers and scientists throughout history. Initially, the discovery and application of antibiotics appeared to be a hopeful and dependable resolution to the issue. Nevertheless, since the bacterial population continues to grow and develop antibiotic resistance through the transfer of genes, it has become imperative to identify an alternative to antibiotic therapy for combating various bacterial strains. Bacteriophage therapy has been seen as a viable option for substitution. Hence, our study aimed to assess the capacity of phage infectivity on various strains of a particular bacterium, as well as on those same strains that have been genetically modified with antibiotic-resistant genes, in order to examine the possible effects of horizontal gene transfer. Our study specifically examined five indigenous infectious strains (O1) of Vibrio Cholerae and two particular antibiotics: Ampicillin and Kanamycin. Additionally, we employed another strain of Vibrio Cholerae as the experimental control. We isolated the pGLO plasmid from E. coli DH5α which contains the Ampicillin resistance gene. Additionally, we obtained the chromosomal DNA from the 1877 strain of Vibrio Cholerae, which carries the Kanamycin-resistant gene. Subsequently, the genes were introduced into the 5 indigenous strains individually, aiming to accomplish horizontal gene transfer in a controlled laboratory setting. Consequently, we experimented on a total of 24 strains of Vibrio Cholerae. These included 5 naturally occurring strains WT391, WT428, WT429, WT435, and WT439 that were genetically modified with the Ampicillin resistance gene, and also were genetically modified with the Kanamycin resistance gene, and one control strain (specifically, the 1877 strain of Vibrio Cholerae). Subsequently, we conducted a spot test on each strain using 6 phages JSF2, JSF6, JSF7, JSF10, JSF25, and JSF30 from our laboratory inventory. Our objective was to identify any influence of the transformation (horizontal gene transfer) on the infectivity of the phages.