RESUMO
Using PCR-based isolation and sequence analysis of the flagellin gene from two distinct biotypes of Burkholderia pseudomallei, a 15-bp deletion was found within the variable domain of the gene in isolates capable of assimilating arabinose (Ara+). This finding led to the development of a PCR-based method in order to differentiate and identify pathogenic B. pseudomallei for epidemiological study. A pair of specific primers was designed covering the 15-bp deletion region at the variable domain. PCR-amplification products of 176 and 191 bp in size were detected from 41 Ara+ isolates and 39 Ara - isolates of B. pseudomallei, respectively. Moreover, flagellin gene fragments of other bacterial species tested in this study were not amplified using these primers. The results suggest that the flagellin gene sequences of both B. pseudomallei biotypes in this region are stable and distinct. This method can be applied and useful for the epidemiological study of B. pseudomallei.
Assuntos
Burkholderia pseudomallei/genética , DNA Bacteriano/análise , Flagelina/genética , Sequência de Aminoácidos , Arabinose/metabolismo , Técnicas de Tipagem Bacteriana , Burkholderia pseudomallei/classificação , Variação Genética , Humanos , Dados de Sequência Molecular , Reação em Cadeia da Polimerase , Análise de Sequência de DNA , Homologia de Sequência de AminoácidosRESUMO
The flagellin genes of four Burkholderia pseudomallei and two Burkholderia cepacia clinical isolates were studied by a polymerase chain reaction (PCR)-based isolation method using the same pair of primers. The PCR-amplification products of the isolates showed a single band of about 1.1 kb, which is similar to a type II B. cepacia flagellin reported previously. In order to distinguish these two species based on the flagellin PCR-amplified products, Pst I and Xho I restriction endonuclease analysis was performed. The results suggest that there is sufficient diversity within the flagellin sequences of the closely related Burkholderia species, B. pseudomallei and B. cepacia, to enable flagellin-type identification on the basis of the pattern of restriction fragments. In addition, the flagellin gene should be of considerable use as a genetic marker for clinical identification of these organisms.
