Project description:The emergence of multi-drug resistant (MDR) bacteria is recognised today as one of the greatest challenges to public health. As traditional antimicrobials are becoming ineffective and research into new antibiotics is diminishing, a number of alternative treatments for MDR bacteria have been receiving greater attention. Bacteriophage therapies are being revisited and present a promising opportunity to reduce the burden of bacterial infection in this post-antibiotic era. This review focuses on the current evidence supporting bacteriophage therapy against prevalent or emerging multi-drug resistant bacterial pathogens in respiratory medicine and the challenges ahead in preclinical data generation. Starting with efforts to improve delivery of bacteriophages to the lung surface, the current developments in animal models for relevant efficacy data on respiratory infections are discussed before finishing with a summary of findings from the select human trials performed to date.
Project description:hvKP ATCC43816 and its lytic phage H5 were employed as a phage-antibiotic combination model. Based on the comprehensive characterization of phages, including cryo-electron microscopy, we evaluated the synergic effect of H5 on bacterial killing in vitro when combined with multiple antibiotics, and analyzed the advantages of phage-antibiotic combinations from an evolutionary perspective and proposes a novel PAS mechanism by using ceftazidime as an example.
Project description:Bacteriophages are bacterial viruses, capable of killing even multi-drug resistant bacterial cells. For this reason, therapeutic use of phages is considered as a possible alternative to conventional antibiotics. However, phages are very host specific in comparison to wide-spectrum antibiotics and thus preparation of phage-cocktails beforehand against pathogens can be difficult. In this study, we evaluate whether it may be possible to isolate phages on-demand from environmental reservoir. We attempted to enrich infectious bacteriophages from sewage against nosocomial drug-resistant bacterial strains of different medically important species in order to evaluate the probability of discovering novel therapeutic phages. Stability and host-range were determined for the acquired phages. Our results suggest that on-demand isolation of phages is possible against Pseudomonas aeruginosa, Salmonella and extended spectrum beta-lactamase Escherichia coli and Klebsiella pneumoniae. The probability of finding suitable phages was less than 40% against vancomycin resistant Enterococcus and Acinetobacter baumannii strains. Furthermore, isolation of new phages against methicillin resistant Staphylococcus aureus strains was found to be very difficult.
Project description:The emergence of carbapenem-resistant Acinetobacter baumannii has been increasingly reported, leading to more challenges in treating its infections. With the development of phage therapy and phage-antibiotic combinations, it is possible to improve the treatment of bacterial infections. In the present study, a vB_AbaP_WU2001 (vWU2001 for short) phage-specific CRAB was isolated and the genome size is 40,792 bp in length. The novel phage vWU2001 belongs to the Autographiviridae family and the order Caudovirales. Shotgun proteomics identified 289 proteins. The broad host range phage vWU2001 displayed a high adsorption rate, short latent period, large burst size and good stability. The phage could reduce preformed biofilms and inhibit biofilm formation. The combination of phage vWU2001 and colistin had significantly higher bacterial growth inhibition activity than that of phage, or colistin alone. The efficacy of the combined treatment was also evaluated in Galleria mellonella. The evaluation of its therapeutic potential revealed that the combination of phage and colistin showed a significantly greater increase in G. mellonella survival and clearance of bacterial number compared to that of phage or colistin alone, indicating that the combination was synergistic against CRAB. The results demonstrated that phage vWU2001 has the potential to be developed as an antibacterial agent.
Project description:Proteus mirabilis, a prevalent urinary tract pathogen and formidable biofilm producer, especially in Catheter-Associated Urinary Tract Infection, has seen a worrying rise in multidrug-resistant (MDR) strains. This upsurge calls for innovative approaches in infection control, beyond traditional antibiotics. Our research introduces bacteriophage (phage) therapy as a novel non-antibiotic strategy to combat these drug-resistant infections. We isolated P2-71, a lytic phage derived from canine feces, demonstrating potent activity against MDR P. mirabilis strains. P2-71 showcases a notably brief 10-minute latent period and a significant burst size of 228 particles per infected bacterium, ensuring rapid bacterial clearance. The phage maintains stability over a broad temperature range of 30-50°C and within a pH spectrum of 4-11, highlighting its resilience in various environmental conditions. Our host range assessment solidifies its potential against diverse MDR P. mirabilis strains. Through killing curve analysis, P2-71's effectiveness was validated at various MOI levels against P. mirabilis 37, highlighting its versatility. We extended our research to examine P2-71's stability and bactericidal kinetics in artificial urine, affirming its potential for clinical application. A detailed genomic analysis reveals P2-71's complex genetic makeup, including genes essential for morphogenesis, lysis, and DNA modification, which are crucial for its therapeutic action. This study not only furthers the understanding of phage therapy as a promising non-antibiotic antimicrobial but also underscores its critical role in combating emerging MDR infections in both veterinary and public health contexts.
Project description:Pseudomonas syringae pv. phaseolicola (Pph) is a significant bacterial pathogen of agricultural crops, and phage Φ6 and other members of the dsRNA virus family Cystoviridae undergo lytic (virulent) infection of Pph, using the type IV pilus as the initial site of cellular attachment. Despite the popularity of Pph/phage Φ6 as a model system in evolutionary biology, Pph resistance to phage Φ6 remains poorly characterized. To investigate differences between phage Φ6 resistant Pseudomonas syringae pathovar phaseolicola strains, we performed expression analysis of super and non piliated strains of Pseudomonas syringae to determine the genetic cause of resistance to viral infection.
Project description:BackgroundStaphylococcus aureus is an opportunistic Gram-positive bacterium that can form biofilm and become resistant to many types of antibiotics. The treatment of multi-drug resistant Staphylococcus aureus (MDRSA) infection is difficult since it possesses multiple antibiotic-resistant mechanisms. Endolysin and virion-associated peptidoglycan hydrolases (VAPGH) enzymes from bacteriophage have been identified as potential alternative antimicrobial agents. This study aimed to assess the ability of Lactococcus lactis NZ9000 secreting endolysin and VAPGH from S. aureus bacteriophage 88 to inhibit the growth of S. aureus PS 88, a MDRSA.MethodEndolysin and VAPGH genes were cloned and expressed in L. lactis NZ9000 after fusion with the SPK1 signal peptide for secretion. The recombinant proteins were expressed and purified, then analyzed for antimicrobial activity using plate assay and turbidity reduction assay. In addition, the spent media of the recombinant lactococcal culture was analyzed for its ability to inhibit the growth of the S. aureus PS 88.ResultsExtracellular recombinant endolysin (Endo88) and VAPGH (VAH88) was successfully expressed and secreted from L. lactis which was able to inhibit S. aureus PS 88, as shown by halozone formation on plate assays as well as inhibition of growth in the turbidity reduction assay. Moreover, it was observed that the spent media from L. lactis NZ9000 expressing Endo88 and VAH88 reduced the viability of PS 88 by up to 3.5-log reduction with Endo88 being more efficacious than VAH88. In addition, Endo88 was able to lyse all MRSA strains tested and Staphylococcus epidermidis but not the other bacteria while VAH88 could only lyse S. aureus PS 88.ConclusionRecombinant L. lactisNZ9000 expressing phage 88 endolysin may be potentially developed into a new antimicrobial agent for the treatment of MDRSA infection.