Glycosyltransferase: a specific marker for the discrimination of Bacillus anthracis from the Bacillus cereus group.

Bacillus anthracis, the aetiological agent of anthrax, has been taxonomically classified with the Bacillus cereus group, which comprises B. cereus, Bacillus thuringiensis, Bacillus mycoides, Bacillus pseudomycoides and Bacillus weihenstephanensis. Although the pathogenesis and ecological manifestations may be different, B. anthracis shares a high degree of DNA sequence similarity with its group member species. As a result, the discrimination of B. anthracis from its close relatives in the B. cereus group is still quite difficult. Suppression subtractive hybridization (SSH) was performed to search for genomic differences between a B. anthracis Korean isolate CR and the most closely related B. cereus type strain KCTC 3624(T). Two-hundred and five B. anthracis CR clones obtained by SSH underwent Southern hybridization, and comparative sequences were analysed using the blast program from the National Center for Biotechnology Information (NCBI). Subsequently, primer sets based on the glycosyltransferase group 1 family protein gene specific to B. anthracis were designed from the sequences of subtracted clones, and their specificities were evaluated using eight B. anthracis, 33 B. cereus, 10 B. thuringiensis, six B. mycoides, one B. pseudomycoides, one B. weihenstephanensis and 19 strains from 11 other representative Bacillus species. PCR primers specific for the glycosyltransferase group 1 family protein gene did not amplify the desired products from any of the Bacillus strains under examination, except B. anthracis alone. These findings may be useful in the future development of efficient diagnostic tools for the rapid identification of B. anthracis from other members of the B. cereus group.

Bacillus chungangensis sp. nov., a halophilic species isolated from sea sand.

The taxonomic position of a Gram-stain-positive, endospore-forming, halophilic strain, designated CAU 348(T), isolated from sea sand was investigated using a polyphasic approach. Colony morphology, biochemical tests and chemotaxonomic investigations revealed that strain CAU 348(T) had the characteristics of the genus Bacillus. Comparative 16S rRNA gene sequence analysis showed that the organism formed a hitherto unknown subline within the genus Bacillus. Sequence divergence values of more than 4.3 % from other described Bacillus species, together with phenotypic differences, showed that the unidentified bacterium represents a previously unrecognized member of this genus. The genotypic and phenotypic data indicated that strain CAU 348(T) represents a novel species of the genus Bacillus, for which the name Bacillus chungangensis sp. nov. is proposed. The type strain is CAU 348(T) (=KCTC 13566(T) =CCUG 57835(T)).

Pseudoclavibacter chungangensis sp. nov., isolated from activated sludge.

The taxonomic position of a Gram-positive, non-spore-forming strain, designated CAU 59(T), from activated sludge was investigated. Colony morphology, biochemical tests and chemotaxonomic investigations revealed that strain CAU 59(T) possessed the characteristics of the genus Pseudoclavibacter. Comparative 16S rRNA gene sequence analysis showed sequence divergence values between strain CAU 59(T) and other described Pseudoclavibacter species of more than 3.6 %, and the strain formed a hitherto-unknown subline within the genus Pseudoclavibacter. DNA-DNA hybridization studies showed that strain CAU 59(T) displayed 20.9 % relatedness to its closest phylogenetic neighbour, Pseudoclavibacter helvolus DSM 20419(T). The DNA G+C content was 66.2 mol%. The phenotypic, chemotaxonomic and genotypic data indicated that strain CAU 59(T) represents a novel species of the genus Pseudoclavibacter, for which the name Pseudoclavibacter chungangensis sp. nov. is proposed. The type strain is CAU 59(T) (=KCTC 22691(T) =CCUG 58142(T)).

Corynebacterium doosanense sp. nov., isolated from activated sludge.

The taxonomic position of a Gram-positive, non-motile, non-spore-forming coryneform, isolated from activated sludge and designated strain CAU 212(T), was investigated using a polyphasic approach. Cellular morphology, biochemical tests and chemotaxonomic investigations revealed that strain CAU 212(T) had the characteristics of the genus Corynebacterium. Comparative 16S rRNA gene sequence analysis showed that the organism formed a hitherto-unknown subline within the genus Corynebacterium. Sequence divergence values of more than 4.3 % from recognized Corynebacterium species, together with phenotypic differences, showed that the bacterium represents a previously unrecognized member of the genus Corynebacterium, for which the name Corynebacterium doosanense sp. nov. is proposed. The type strain is CAU 212(T) (=KCTC 19568(T)=CCUG 57284(T)).

Lactococcus chungangensis sp. nov., a lactic acid bacterium isolated from activated sludge foam.

The taxonomic position of a Gram-positive coccus, designated strain CAU 28T, isolated from activated sludge foam was determined by using a polyphasic approach. Based on its cellular morphology and the results of biochemical tests, strain CAU 28T was identified tentatively as a member of the genus Lactococcus. Comparative 16S rRNA gene sequence analysis showed that levels of similarity between strain CAU 28T and the type strains of recognized Lactococcus species ranged from 90.4 to 97.2 %. DNA-DNA hybridization studies showed that strain CAU 28T displayed less than 26.1 % relatedness to the type strains of recognized Lactococcus species. The rep-PCR fingerprints revealed that strain CAU 28T was well separated from reference Lactococcus species. The combined genotypic and phenotypic data indicate that strain CAU 28T represents a novel species of the genus Lactococcus, for which the name Lactococcus chungangensis sp. nov. is proposed. The type strain is CAU 28T (=KCTC 13185T =CCUG 55099T).

Detection of unusual rotavirus genotypes G8P[8] and G12P[6] in South Korea.

Five hundred four fecal specimens, collected between 2004 and 2006 from young children with acute diarrhea, were screened for rotavirus by ELISA with VP6-specific antibody. Of these samples, 394 (78.2%) were confirmed as group A rotavirus and they underwent G- and P typing using a combination of ELISA, RT-PCR, and sequence analysis methods. The dominant circulating G serotype was G1 (35.6%) followed by G3 (26.4%), G4 (14.7%), and G2 (11.9%). There was a low prevalence of G9 (1.0%) and of unusual G type rotavirus, in particular, G12 (0.5%) and G8 (0.3%). Of the P genotype rotavirus in circulation, P[8] (53.0%) was most common followed by P[6] (15.5%), P[4] (15.2%), and P[9] (2.3%). Determination of G- and P type combinations revealed that G1P[8] strains were most prevalent (25.4%), amid G3P[8] (16.8%), G2P[4] (6.3%), and G4P[6] (6.1%) strains. Unusual or rare combinations such as G2P[6], G2P[8], G3P[4], G2P[9], G1P[9], G3P[9], G12P[6], G1P[4], G3P[6], and G8P[8] were also found. Owing to the recent emergence of G8 and G12 rotavirus, the findings from this study are important since they provide new information concerning the local and global spread of rotavirus genotypes.