Environmental Effects on Mycobacteriophage Cepens

Abstract

Bacteriophage (phage) are viruses that infect and use bacterial hosts for viral replication. Study of these bacterial viruses has led to such discoveries as knowing DNA is the molecule of inheritance12. Study of phage has also led to discovery and implementation of novel therapeutic treatment of infections. Known as “phage therapy”, phage have been utilized in curing a patient of the highly virulent infection known as MRSA11. Tuberculosis, caused by Mycobacterium tuberculosis, is a growing concern as antibiotic-resistant strains become more prevalent in the population. Cepens is a lytic phage that infects members of the Mycobacterium genus. This study analyzes Cepens and its interactions with its host bacteria, Mycobacterium smegmatis, in an effort to understand how environmental conditions impact infection and replication efficiency. First, infection benchmarks were established by conducting a serial dilution and plaque assay under standard conditions. Baseline titer calculations were used for comparison after alteration of incubation temperature and pH of phage, both prior to and during infection. Extreme temperatures and pH were expected to lead to a decrease in infectivity as well as potential degradation of the phage itself. Analysis of this data indicates that extremes in either pH or temperature decrease phage viability as well as its ability to establish successful infection.