RESUMO
Molecular epidemiology is one of the most rapidly developing research area. In the light of past and modern technologies it has gained number of typing methods based on molecular biology techniques. In this report, the subspecies differentiation of Francisella tularensis and genotyping of strains isolated in Poland and other geographic locations were investigated using real-time PCR and multispacer typing (MST) methods respectively. In total, 49 strains of F. tularensis included 15 strains from Poland, for subspecies differentiation the real-time PCR method was applied. For molecular typing using MST method four intergenic spacers (IS) were sequenced and compared with those previously described and deposited in GenBank (NCBI). Phylogenetic testing was performed using with the UPGMA model using MEGA6 software. The real-time PCR enables to distinguish five strains belonged to type A and 44 to type B among deposited F. tularensis strains. The MST revealed previously described genotypes, as well as 23 new genotypes were detected. The use of real-time PCR and MST method are valuable in the analysis of F. tularensis. SIGNIFICANCE AND IMPACT OF THE STUDY: This study demonstrate convenient molecular tools (real-time PCR and multispacer typing) for Francisella tularensis detection, differentiation and genotyping which can be applied for molecular epidemiological studies and providing useful information for scientific research and during natural tularaemia outbreaks.
Assuntos
Francisella tularensis , Epidemiologia Molecular/métodos , Tipagem Molecular/métodos , Proteínas da Membrana Bacteriana Externa/genética , Proteínas de Bactérias/genética , Sequência de Bases , DNA Bacteriano/genética , DNA Intergênico/genética , Francisella tularensis/classificação , Francisella tularensis/genética , Francisella tularensis/isolamento & purificação , Genótipo , Humanos , Lipoproteínas/genética , Filogenia , Polônia , Reação em Cadeia da Polimerase em Tempo Real , Tularemia/diagnóstico , Tularemia/microbiologiaRESUMO
Bacillus anthracis is a spore-forming, Gram-positive microorganism. It is a causative agent of anthrax, a highly infectious disease. It belongs to the "Bacillus cereus group", which contains other closely related species, including Bacillus cereus, Bacillus thuringiensis, Bacillus mycoides, Bacillus weihenstephanensis, and Bacillus pseudomycoides. B. anthracis naturally occurs in soil environments. The BA5345 genetic marker was used for highly specific detection of B. anthracis with TaqMan probes. The detection limit of a real-time PCR assay was estimated at the level of 16.9 copies (CI95% - 37.4 to 37.86, SD = 0.2; SE = 0.118). Oligonucleotides designed for the targeted sequences (within the tested locus) revealed 100 % homology to B. anthracis strain reference sequences deposited in the database (NCBI) and high specificity to all tested B. anthracis strains. Additional in silico analysis of plasmid markers pag and cap genes with B. anthracis strains included in the database was carried out. Our study clearly indicates that the BA5345 marker can be used with success as a chromosomal marker in routine identification of B. anthracis; moreover, detection of plasmid markers indicates virulence of the examined strains.