Products derived from Cannabis sativa L. have gained increased interest and popularity. As these products become common amongst the public, the health and potential therapeutic values associated with hemp have become a premier focus of research. While the psychoactive and medicinal properties of Cannabis products have been extensively highlighted in the literature, the antibacterial properties of cannabidiol (CBD) have not been explored in depth. This research serves to examine the antibacterial potential of CBD against Salmonella newington and S. typhimurium. In this study, we observed bacterial response to CBD exposure through biological assays, bacterial kinetics, and fluorescence microscopy. Additionally, comparative studies between CBD and ampicillin were conducted against S. typhimurium and S. newington to determine comparative efficacy. Furthermore, we observed potential resistance development of our Salmonella spp. against CBD treatment.

The E34 phage is a member of the podoviridae family of phages, (short non-contractile tailed bacteriophages) that uses Salmonella newington as its host. This phage initiates the infection of its host via a specific interaction between its tailspike protein (TSP) and the lipopolysaccharides (LPS) of the bacterial. The E34 TSP is structurally similar and functionally equivalent to the P22 phage whose TSP has been well characterized and electron micrographs of both phages appear indistinguishable. The crystal structure of P22 phage TSP in complex with the O-antigen of S. typhimurium has been determined; and the active site of the TSP demonstrated to be the residues Asp392, Asp395 and Glu359 of the receptor binding domain. In another phage called E15, a phylogenetic relative of E34 phage, a short polysaccharide consisting of alpha-Gal-Man-Rha repeating units is responsible for the interaction between the E15 phage and Salmonella anatum LPS leading to the adsorption of the phage to the bacteria. Studies on E34 phage shows that it interacts with Salmonella newington O antigen polysaccharide component of the LPS, this polysaccharide consists of mannosyl-rhamnosyl-galactose repeating units joined together by beta-galactosyl linkages. However, no data exist regarding the specific residues of E34 TSP that are responsible for LPS binding and hydrolysis. In this study, the tailspike gene was cloned onto vector pET30a-LIC and expressed as a fusion protein termed the extended E34 TSP (EE34 TSP). We characterized the protein based on resistance to heat, SDS, and proteases; showing that the protein is heat resistant, shows aberrant electrophoretic mobility in the presence of SDS gradient, and actively binds to P22 phage heads to form hybrid phages that cannot infect P22 host. We also demonstrate via in silico study that the E34 TSP binds to and hydrolyses the O-antigen of its host via the ALA250, SER279 and ASP280 residues. Finally, testing E34 phage ability to protect Vero cells from Salmonella infection shows highly encouraging results, implying that E34 phage can be used in therapeutic or preventive medicine.

The prevalence of multidrug resistant bacterial diseases is a major global health risk. Multidrug resistant bacterial diseases are prevalent, and the need for novel methods of treatment is essential to the preservation of public health. Annually foodborne pathogens cause 1.35 million infections and 26,500 hospitalizations in the United States alone. Foodborne pathogens such as Salmonella spp. are a major threat to public health. Bacteriophages offer a unique method for the treatment of these multidrug resistant bacteria. We studied the infection dynamics of a potential mono-phage therapy of Salmonella typhimurium under various pathophysiological conditions. Furthermore, we determined the resistance dynamics of Salmonella typhimurium against P22 phage treatment. We also determined synergy with antibiotics such as ampicillin and kanamycin. This research helps to further define and show the versatility of bacteriophages as potential novel treatment methods.

Salmonella can cause acute and chronic infections in humans. Salmonella species are known to cause food poisoning and other diseases in developing countries. Their role in the pathogenesis of these diseases has received increased international attention. Despite numerous advances in sanitation, they still can infect humans and cause outbreaks in developed countries. For example, Salmonella causes about 1.2 million illnesses in the US each year with over 450 deaths. Additionally, Salmonella outbreaks cause significant losses to chicken producers globally. The Salmonella species is also prone to acquiring resistance to various classes of antibiotics. Hence, the need for a paradigm shift from antibiotics to bacteriophages to manage, control and treat bacterial infections. The ɛ34 phage belongs to Podoviruses and categorized into the P22-like phages. The P22-like phages include ɛ34, ES18, P22, ST104, and ST64T. In this work, we investigated the antibacterial property of ɛ34 phage tailspike protein against Salmonella newington (S. newington). We demonstrate here that, the phage’s tailspike protein enzymatic property as a LPS hydrolase synergizes with Vero Cell culture supernatant in killing S. newington. Using decellularized cartilage scaffold as an ex vivo tissue model, the ɛ34 TSP protected the scaffold from S. newington biofilm formation. Computational analysis of the ɛ34 TSP interaction with membrane proteins of S. newington demonstrated a higher probability (0.7318) of binding to ompA of S. newington, and when docked to ompA extracellular component, it produced a high free energy of -11.3kcal/mol. We also demonstrate the resistance/sensitivity of the tailspike to the digestive enzyme trypsin. The data obtained in this work indicates that the trypsin resistant tailspike protein of Ɛ34 phage can be formulated as a novel antibacterial agent against S. newington.

Bacteriophages have been regarded as biocontrol agents that can be used in the food industry. They can be used in various applications, such as pathogen detection and bio-preservation. Their potential to improve the quality of food and prevent foodborne illness is widespread. These bacterial viruses can also be utilized in the preservation of various other food products. The specificity and high sensitivity of bacteriophages when they lyse bacterial targets have been regarded as important factors that contribute to their great potential utility in the food industry. This review will provide an overview of their current and potential applications.