Although mutation occurs randomly in nature and is passed randomly between bacterial species, the misuse and overuse of antibiotics in modern medicine has selected for antibiotic resistant organisms, resulting in an epidemic of antibiotic resistant infections. Used extensively in former Soviet Union countries with success, Western researchers have begun considering phage therapy for treatments, however it must be subjected to rigorous clinical trials before it can be approved by the FDA as a treatment method in North America (Gill et al. 2010; Abhilash et al. 2009).
In this study, phage screening was performed on eight MDR bacterial strains provided from LifeLabs and Royal Inland Hospital in Kamloops, B.C.: E. coli 15-102, 15-124, and 14-318; Micrococcus luteus; Methicillin Resistant Staphylococcus Aureus (MRSA) 1 and 2; Serratia marcescens; and Mycobacterium smegmatis. One non-resistant E. coli strain known to be killed by phages found in Kamloops sewage was used as a positive control. Seven water samples and one non-water sample were used in this experiment as a source of phages. Water samples were obtained from the Kamloops Sewage Treatment Plant, the Domtar pulp mill run-off, the Pacific Ocean, Bisaro Anima Cave, and alkaline ponds around Kamloops. The non-water sample was created from mixing dirt from Abbotsford, B.C. with sterile water. An additional enriched water sample was made through the incubation of broth culture, nutrient broth, and sewage water overnight at 37°C in an attempt to select for more strain-specific phages (Prescott et al. 2005). In addition, sterile water was used in the protocol as a negative control.
The successfulness of each phage screening trial was measured through the formation of plaques, which developed after plating the Multiple Drug Resistant (MDR) bacteria, molten agar, and phages for confluent growth on nutrient agar (Prescott et al. 2005). Of all the bacteria and environmental water samples, plaques only developed for the E. coli 14-318 strain using sewage water from the Kamloops Sewage Treatment Center. Using phage screening against these MDR bacteria allowed us to see that MDR pathogens present in our community are treatable with a potentially more beneficial and successful method to antibiotics.