BACTERIAL TYPING METHODS

Bacterial typing methods may be applied in several types of research: in tracking sources and pathways of infection spreading, in examination of infectious diseases, and in population genetics. The method is considered as successful when identified bacterial types are stable and the applied technique has sufficient discriminatory power. The method has to be simple, reproducible, and standardized, too. In bacterial strains typing, both can be used, phenotype and genotype characteristics' analysis. The most applied phenotyping methods are: serotyping, resistotyping, phagotyping, bacteriocin typing, and biotyping. Recently, these methods have been improved by applying molecular biology techniques which allow analyses of the whole cell proteins, outer membrane proteins, cell lipopolysaccharides, and multiple-locus bacterial enzymes. Genotyping methods include determination of plasmid profile, analysis of chromosomal DNA (genome fingerprinting), pulsed-field gel electrophoresis, gene probes, ribotyping, insertional sequences analysis, polymerase chain reaction-based methods, repetitive deoxyribonucleic acid sequences analysis, and deoxyribonucleic acid microarrays. In genotyping methods especially, for profiles comparison of obtained types, the application of specialized software is often necessary. Probably, in the future, genotyping and molecular typing methods will take place instead of classic techniques. Nowadays, using some of these analyses can be expensive and requires specialized staff, but these methods have one unique advantage - high discriminatory level.