Alex R. Hoffmaster1, Karen K. Hill2, Jay E. Gee1, Chung K. Marston1, Barun K. De1, Tanja Popović3, David Sue1, Patricia P. Wilkins1, Swati Avashia4,2, Rahsaan Drumgoole2, Charles H. Helma5, Lawrence O. Ticknor6, Richard T. Okinaka5, Paul J. Jackson7
1Epidemiologic Investigations Laboratory, Meningitis and Special Pathogens Branch, MS G34
2Infectious Disease Epidemiology and Surveillance Division, T-801, Texas Department of State Health Services, Austin, Texas 78756
3Office of the Director
4Epidemic Intelligence Service, MS E92, Centers for Disease Control and Prevention, 1600 Clifton Road, Atlanta, Georgia 30333
5Bioscience
6Decision Applications Divisions, Los Alamos National Laboratory, Los Alamos, New Mexico 87545
7Defense Biology Division, Lawrence Livermore National Laboratory, Livermore, California 94551
Tóm tắt
ABSTRACT
Bacillus cereus
is ubiquitous in nature, and while most isolates appear to be harmless, some are associated with food-borne illnesses, periodontal diseases, and other more serious infections. In one such infection,
B. cereus
G9241 was identified as the causative agent of a severe pneumonia in a Louisiana welder in 1994. This isolate was found to harbor most of the
B. anthracis
virulence plasmid pXO1 (13). Here we report the characterization of two clinical and one environmental
B. cereus
isolate collected during an investigation of two fatal pneumonia cases in Texas metal workers. Molecular subtyping revealed that the two cases were not caused by the same strain. However, one of the three isolates was indistinguishable from
B. cereus
G9241. PCR analysis demonstrated that both clinical isolates contained
B. anthracis
pXO1 toxin genes. One clinical isolate and the environmental isolate collected from that victim's worksite contained the
cap A
,
B
, and
C
genes required for capsule biosynthesis in
B. anthracis
. Both clinical isolates expressed a capsule; however, neither was composed of poly-
d
-glutamic acid. Although most
B. cereus
isolates are not opportunistic pathogens and only a limited number cause food-borne illnesses, these results demonstrate that some
B. cereus
strains can cause severe and even fatal infections in patients who appear to be otherwise healthy.
