Differentiation of Rickettsiae by groEL Gene Analysis

Abstract

The nucleotide sequences (534 to 546 bp) of the groEL gene, which encodes the 60-kDa heat shock protein GroEL, from 15 rickettsial strains were determined and compared. In the phylogenetic tree created by the unweighted pair group method with arithmetic averages and the neighbor-joining method, rickettsial strains could be distinguished from Ehrlichia strains. Five spotted fever group strains, four typhus group strains, and six scrub typhus group (STG) strains were differentiated as distinct entities. Unlike gltA and ompA gene analyses, differentiation between members of the genus Rickettsia and the STG rickettsiae by groEL gene analysis was possible. In comparison with 16S rRNA gene analysis, the groEL gene has a higher degree of divergence among the rickettsiae. We therefore successfully developed rapid differentiation methods, PCRrestriction fragment length polymorphism analysis and a species-specific PCR, based on the groEL gene sequences. Four Korean isolates were identified by these methods and groEL gene analysis. The results suggest that the groEL gene is useful for the identification and characterization of rickettsiae.

Differentiation of Anaplasmataceae through Partial groEL Gene Analysis

“…1,400 nucleotide sequences (8). Phylogenetic analysis based on the heat shock operon (groESL) has also been developed and was useful for the characterization and identification of Anaplasmataceae (16).…”

“…Recently, the partial groEL gene was used to identify Borrelia and rickettsiae (8,9). The groEL genes, which encode the 60-kDa heat shock protein GroEL, are ubiquitous in both prokaryotes and eukaryotes and encode highly conserved housekeeping proteins, which are essential for cell survival.…”

Laboratory Diagnosis and Genotype Identification of Scrub Typhus from Pinggu District, Beijing, 2008 and 2010

“…GroEL gene sequences have higher degrees of divergence among the rickettsiae, and they have been proven to be able to facilitate the rapid diagnosis of rickettsial diseases and differentiate rickettsial diseases from other acute febrile diseases. 8,9 In the present study, the phylogenetic tree of groEL gene sequences forms two clusters of It has been reported that the virulence of O. tsutsugamushi is related to its serotype or genotype. 19 However, serotyping is time-and labor-consuming, and it is limited by the need to include all prototype strains when testing a new strain.…”

“…The phylogenetic analysis was performed with nucleotide sequences of the O. tsutsugamshi groEL gene and the 56 kDa gene as described by others. 8,12 Immunofluorescence assay. We obtained acute-phase anticoagulated serum from each of 52 patients and six convalescent-phase sera.…”

“…A nested polymerase chain reaction (PCR) according to the groEL gene as recommended by the China CDC (Professor Lijuan, Zhang, unpublished data) and also reported by others 8,9 was used as a detection method for O. tsutsugamushi for all samples. Primers Gro-1, 5 -AAGAAGGA/CGTGATAAC-3 and Gro-2, 5 -ACTTCA/CGTAGCACC-3 were used in the first PCR.…”