RESUMO
Serratia marcescens (GBB151) was isolated and genetically modified for high-yielding pigment production capacitythat could be employed for industrial purposes. Ethidium bromide-induced mutagenesis of GBB151 resulted inthe generation of eight mutant isolates (GBB151Ea-GBB151Eh). The chemical mutants of S. marcescens obtainedproduced 5-fold more pigment than the wild-type organism. The wild-type GBB151 produced 413.9 unit/cell,while the mutant strains produced pigments with yields ranging from 841.7 to 2008.5 unit/cell. Random amplifiedpolymorphic deoxyribonucleic acid-polymerase chain reaction analysis showed different amplicons patterns of nativeas well as mutant derivatives. The factorial analysis diagram and the dendrogram showed a degree of dissimilarityamong the wild-type bacterial isolate GBB151 and its mutants. Mutant strains GBB151Ec and GBB151Ef wereclosest to the wild type as they appeared in the same quadrant. GBB151Ed which had lost its ability to producepigment was farthest and in the different quadrant to the wild type. These study provided insight into improvement inpigment production by manipulating genetic make-up of S. marcescens, thus meeting industrial demand.
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.