RESUMO
OBJECTIVES: The emergence of resistant bacteria is being increasingly reported around the world, potentially threatening millions of lives. Amongst resistant bacteria, methicillin-resistant Staphylococcus aureus (MRSA) is the most challenging to treat. This is due to emergent MRSA strains and less effective traditional antibiotic therapies to Staphylococcal infections. The use of bacteriophages (phages) against MRSA is a new, potential alternate therapy. In this study, morphology, genetic and protein structure of lytic phages against MRSA have been analysed. METHODS: Isolation of livestock and sewage bacteriophages were performed using 0.4 μm membrane filters. Plaque assays were used to determine phage quantification by double layer agar method. Pure plaques were then amplified for further characterization. Sulfate-polyacrylamide gel electrophoresis and random amplification of polymorphic DNA were run for protein evaluation, and genotyping respectively. Transmission electron microscope was also used to detect the structure and taxonomic classification of phage visually. RESULTS: Head and tail morphology of bacteriophages against MRSA were identified by transmission electron microscopy and assigned to the Siphoviridae family and the Caudovirales order. CONCLUSION: Bacteriophages are the most abundant microorganism on Earth and coexist with the bacterial population. They can destroy bacterial cells successfully and effectively. They cannot enter mammalian cells which saves the eukaryotic cells from lytic phage activity. In conclusion, phage therapy may have many potential applications in microbiology and human medicine with no side effect on eukaryotic cells.
Assuntos
Humanos , Ágar , Bactérias , Bacteriófagos , Caudovirales , Classificação , DNA , Eletroforese , Células Eucarióticas , Cabeça , Gado , Membranas , Resistência a Meticilina , Staphylococcus aureus Resistente à Meticilina , Métodos , Microscopia Eletrônica de Transmissão e Varredura , Microscopia Eletrônica de Transmissão , Esgotos , Siphoviridae , Infecções Estafilocócicas , CaudaRESUMO
One of the most economically important bacterial pathogens of plants and plant products is
Assuntos
Bacteriófagos/isolamento & purificação , Agentes de Controle Biológico/isolamento & purificação , Dickeya chrysanthemi/crescimento & desenvolvimento , Dickeya chrysanthemi/virologia , Doenças das Plantas/microbiologia , Solanum tuberosum/microbiologia , Sequência de Bases , Bacteriófagos/classificação , Agentes de Controle Biológico/classificação , DNA Bacteriano/genética , Testes de Sensibilidade Microbiana , Dados de Sequência Molecular , Myoviridae/classificação , Myoviridae/isolamento & purificação , Dickeya chrysanthemi/efeitos dos fármacos , Dickeya chrysanthemi/isolamento & purificação , /genética , Análise de Sequência de DNA , Siphoviridae/classificação , Siphoviridae/isolamento & purificaçãoRESUMO
Some clinical isolates of Pseudomonas aeruginosa stored in our culture collection did not grow or grew poorly and showed lysis on the culture plates when removed from the collection and inoculated on MacConkey agar. One hypothesis was that bacteriophages had infected and killed those clinical isolates. To check the best storage conditions to maintain viable P. aeruginosa for a longer time, clinical isolates were stored at various temperatures and were grown monthly. We investigated the presence of phage in 10 clinical isolates of P. aeruginosa stored in our culture collection. Four strains of P. aeruginosa were infected by phages that were characterized by electron microscopy and isolated to assess their ability to infect. The best condition to maintain the viability of the strains during storage was in water at room temperature. Three Siphoviridae and two Myoviridae phages were visualized and characterized by morphology. We confirmed the presence of bacteriophages infecting clinical isolates, and their ability to infect and lyse alternative hosts. Strain PAO1, however, did not show lysis to any phage. Mucoid and multidrug resistant strains of P. aeruginosa showed lysis to 50% of the phages tested.