title: DnaJ sequences of Bacillus cereus strains isolated from outbreaks of hospital infection are highly similar to Bacillus anthracis.
abstract: Bacillus cereus is becoming an important nomosomial pathogen because of frequent isolation from blood cultures and from severe systemic infections. To differentiate highly pathogenic outbreak strain of B. cereus from other sources of the Bacillus cereus, we attempted to analyze their dnaJ sequences. Assays indicated that dnaJ sequence similarity of all of 52 blood culture isolates of B. cereus ranged from 92.8% to 100%. The distance between B. anthracis and B. cereus except six outbreak isolates ranged from 3.8% to 6.4%. The dnaJ sequences of six outbreak strains of B. cereus (GTC 02891, GTC 02896, GTC 02916, GTC 02917, GTC 03221, and GTC 03222) were closely related to those of B. anthracis (99.2%-99.5% sequence similarity). Ba813 sequences were only found in the six outbreak strains of B. cereus. The other pathogenic factors of B. anthracis were not found in these six outbreak strains, with the exception of GTC 02891 (cap-positive). The six outbreak strains formed clear β-hemolytic colonies on a sheep blood agar plate. Our findings suggest that outbreak strains of B. cereus isolated from blood cultures are likely to have the risk of causing serious infection, and dnaJ and Ba813 are important markers to identify such strains. Phylogenetic analysis of dnaJ and MLST revealed that the six outbreak strains of B. cereus are closely related to B. anthracis.
authors.affiliation: Department of Microbiology, Regeneration and Advanced Medical Science, Gifu University Graduate School of Medicine, Gifu, Japan.
authors.forename: Jiwei
authors.initials: J
authors.lastname: Zhang
authors.forename: Pham
authors.initials: P
authors.lastname: van Hung
authors.forename: Masahiro
authors.initials: M
authors.lastname: Hayashi
authors.forename: Shigeru
authors.initials: S
authors.lastname: Yoshida
authors.forename: Kiyofumi
authors.initials: K
authors.lastname: Ohkusu
authors.forename: Takayuki
authors.initials: T
authors.lastname: Ezaki
mesh_terms: D001408:Bacillus anthracis / Q000235:genetics*; D001409:Bacillus cereus / Q000145:classification / Q000235:genetics* / Q000302:isolation & purification*; D016470:Bacteremia / Q000453:epidemiology / Q000382:microbiology; D016000:Cluster Analysis; D003428:Cross Infection / Q000453:epidemiology* / Q000382:microbiology; D003470:Culture Media / Q000737:chemistry; D004269:DNA, Bacterial / Q000737:chemistry / Q000235:genetics; D004196:Disease Outbreaks; D016908:Gram-Positive Bacterial Infections / Q000453:epidemiology* / Q000382:microbiology; D050956:HSP40 Heat-Shock Proteins / Q000235:genetics*; D006461:Hemolysis; D006801:Humans; D008969:Molecular Sequence Data; D058885:Multilocus Sequence Typing; D010802:Phylogeny; D017422:Sequence Analysis, DNA
chemical_list: D003470:Culture Media; D004269:DNA, Bacterial; D050956:HSP40 Heat-Shock Proteins