Identification of anthrax toxin genes in a Bacillus cereus associated with an illness resembling inhalation anthrax.
Bacillus anthracis is the etiologic agent of anthrax, an acute fatal disease among mammals. It was thought to differ from Bacillus cereus, an opportunistic pathogen and cause of food poisoning, by the presence of plasmids pXO1 and pXO2, which encode the lethal toxin complex and the poly-gamma-d-glutamic acid capsule, respectively. This work describes a non-B. anthracis isolate that possesses the anthrax toxin genes and is capable of causing a severe inhalation anthrax-like illness. Although initial phenotypic and 16S rRNA analysis identified this isolate as B. cereus, the rapid generation and analysis of a high-coverage draft genome sequence revealed the presence of a circular plasmid, named pBCXO1, with 99.6% similarity with the B. anthracis toxin-encoding plasmid, pXO1. Although homologues of the pXO2 encoded capsule genes were not found, a polysaccharide capsule cluster is encoded on a second, previously unidentified plasmid, pBC218. A/J mice challenged with B. cereus G9241 confirmed the virulence of this strain. These findings represent an example of how genomics could rapidly assist public health experts responding not only to clearly identified select agents but also to novel agents with similar pathogenic potentials. In this study, we combined a public health approach with genome analysis to provide insight into the correlation of phenotypic characteristics and their genetic basis.
Hoffmaster
Alex R
AR
Epidemiologic Investigations Laboratory, Meningitis and Special Pathogens Branch, Centers for Disease Control and Prevention, 1600 Clifton Road, MS G34, Atlanta, GA 30333, USA.
Ravel
Jacques
J
Rasko
David A
DA
Chapman
Gail D
GD
Chute
Michael D
MD
Marston
Chung K
CK
De
Barun K
BK
Sacchi
Claudio T
CT
Fitzgerald
Collette
C
Mayer
Leonard W
LW
Maiden
Martin C J
MC
Priest
Fergus G
FG
Barker
Margaret
M
Jiang
Lingxia
L
Cer
Regina Z
RZ
Rilstone
Jennifer
J
Peterson
Scott N
SN
Weyant
Robbin S
RS
Galloway
Darrell R
DR
Read
Timothy D
TD
Popovic
Tanja
T
Fraser
Claire M
CM
D000818:Animals; D000881:Anthrax / Q000209:etiology; D000942:Antigens, Bacterial; D001408:Bacillus anthracis / Q000145:classification / Q000166:cytology / Q000235:genetics; D001409:Bacillus cereus / Q000145:classification / Q000166:cytology / Q000235:genetics* / Q000472:pathogenicity*; D001427:Bacterial Toxins / Q000235:genetics*; D016680:Genome, Bacterial; D023281:Genomics; D006801:Humans; D051379:Mice; D010957:Plasmids / Q000235:genetics
D000942:Antigens, Bacterial; D001427:Bacterial Toxins; C030325:anthrax toxin