Considerations for distinguishing influenza-like illness from inhalational anthrax.
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CDC has issued guidelines on the evaluation of persons with a history of exposure to Bacillus anthracis spores or who have an occupational or environmental risk for anthrax exposure. This notice describes the clinical evaluation of persons who are not known to be at increased risk for anthrax but who have symptoms of influenza-like illness (ILI). Clinicians evaluating persons with ILI should consider a combination of epidemiologic, clinical, and, if indicated, laboratory and radiographic test results to evaluate the likelihood that inhalational anthrax is the basis for ILI symptoms. (+info)
Interim guidelines for investigation of and response to Bacillus anthracis exposures.
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Environmental Sampling. Environmental testing to detect B. anthracis on surfaces or in the air can be used to investigate known or suspected exposure events. The highest priority of an investigation is to evaluate the risk for exposure to aerosolized B. anthracis spores. Persons collecting and testing samples should 1) obtain adequate samples, 2) avoid cross-contamination during processing, and 3) ensure proficient laboratory testing and interpretation of test results. A positive laboratory test for B. anthracis from a sample of an environmental surface may be caused by cross-contamination from an exposure vehicle (e.g., contact with an envelope containing B. anthracis), background occurrence of B. anthracis spores in the environment, or previously aerosolized B. anthracis that has settled onto environmental surfaces. Laboratory test results of environmental surface samples should not be the only criterion for starting, continuing, or stopping antimicrobial prophylaxis for inhalational disease. (+info)
Update: Investigation of bioterrorism-related anthrax, 2001.
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This report updates the investigation of bioterrorism-related anthrax and the provision of antimicrobial prophylaxis to exposed persons and highlights CDC assistance to other countries investigating cases of bioterrorism-related anthrax. Since November 7, 2001, CDC and state and local public health agencies have identified no new cases of bioterrorism-related anthrax. As of November 14, a total of 22 cases of anthrax has met the CDC case definition; 10 were confirmed inhalational anthrax, and 12 (seven confirmed and five suspected) were cutaneous anthrax. Investigation of a case of inhalational anthrax in a hospital stock room worker aged 61 years in New York City (NYC) found no evidence of anthrax contamination at the work site or home; the source of exposure is unknown. Environmental clean-up of contaminated facilities continues, and surveillance for newcases of bioterrorism-related anthrax is ongoing in Delaware (DE), District of Columbia (DC), Florida (FL), Maryland (MD), New Jersey (NJ), NYC, Pennsylvania (PA), Virginia (VA), and other states. (+info)
Molecular investigation of the Aum Shinrikyo anthrax release in Kameido, Japan.
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In 1993, the Aum Shinrikyo cult aerosolized Bacillus anthracis spores over Kameido, Japan. Spore samples were obtained from the release site, cultured, and characterized by molecular genetic typing. The isolates were consistent with strain Sterne 34F2, which is used in Japan for animal prophylaxis against anthrax. (+info)
Bacillus anthracis pXO1 plasmid sequence conservation among closely related bacterial species.
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The complete sequencing and annotation of the 181.7-kb Bacillus anthracis virulence plasmid pXO1 predicted 143 genes but could only assign putative functions to 45. Hybridization assays, PCR amplification, and DNA sequencing were used to determine whether pXO1 open reading frame (ORF) sequences were present in other bacilli and more distantly related bacterial genera. Eighteen Bacillus species isolates and four other bacterial species were tested for the presence of 106 pXO1 ORFs. Three ORFs were conserved in most of the bacteria tested. Many of the pXO1 ORFs were detected in closely related Bacillus species, and some were detected only in B. anthracis isolates. Three isolates, Bacillus cereus D-17, B. cereus 43881, and Bacillus thuringiensis 33679, contained sequences that were similar to more than one-half of the pXO1 ORF sequences examined. The majority of the DNA fragments that were amplified by PCR from these organisms had DNA sequences between 80 and 98% similar to that of pXO1. Pulsed-field gel electrophoresis revealed large potential plasmids present in both B. cereus 43881 (341 kb) and B. thuringiensis ATCC 33679 (327 kb) that hybridized with a DNA probe composed of six pXO1 ORFs. (+info)
Plasmid-encoded autolysin in Bacillus anthracis: modular structure and catalytic properties.
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A Bacillus anthracis virulence plasmid-encoded peptidoglycan hydrolase (AmiA) with sequence similarity to N-acetylmuramoyl-L-alanine amidases hydrolyzes peptidoglycan independently of cell wall binding. Residues H341, E355, H415, and E486 are absolutely required for catalysis. Many AmiA paralogs are fused to different sorting signals, suggesting that these modular proteins result from domain shuffling. (+info)
Bioterrorism-related inhalational anthrax: the first 10 cases reported in the United States.
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From October 4 to November 2, 2001, the first 10 confirmed cases of inhalational anthrax caused by intentional release of Bacillus anthracis were identified in the United States. Epidemiologic investigation indicated that the outbreak, in the District of Columbia, Florida, New Jersey, and New York, resulted from intentional delivery of B. anthracis spores through mailed letters or packages. We describe the clinical presentation and course of these cases of bioterrorism-related inhalational anthrax. The median age of patients was 56 years (range 43 to 73 years), 70% were male, and except for one, all were known or believed to have processed, handled, or received letters containing B. anthracis spores. The median incubation period from the time of exposure to onset of symptoms, when known (n=6), was 4 days (range 4 to 6 days). Symptoms at initial presentation included fever or chills (n=10), sweats (n=7), fatigue or malaise (n=10), minimal or nonproductive cough (n=9), dyspnea (n=8), and nausea or vomiting (n=9). The median white blood cell count was 9.8 X 10(3)/mm(3) (range 7.5 to 13.3), often with increased neutrophils and band forms. Nine patients had elevated serum transaminase levels, and six were hypoxic. All 10 patients had abnormal chest X-rays; abnormalities included infiltrates (n=7), pleural effusion (n=8), and mediastinal widening (seven patients). Computed tomography of the chest was performed on eight patients, and mediastinal lymphadenopathy was present in seven. With multidrug antibiotic regimens and supportive care, survival of patients (60%) was markedly higher (<15%) than previously reported. (+info)
Control of anthrax toxin gene expression by the transition state regulator abrB.
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Bacillus anthracis produces the anthrax toxin proteins protective antigen (PA), lethal factor (LF), and edema factor (EF) in a growth phase-dependent manner when cultured in liquid medium. Expression of the toxin genes pagA, lef, and cya peaks in late log phase, and steady-state levels of the toxin proteins are highest during the transition into stationary phase. Here we show that an apparent transition state regulator negatively regulates toxin gene expression. We identified two orthologues of the B. subtilis transition state regulator abrB in the B. anthracis genome: one on the chromosome and one on the 182-kb virulence plasmid pXO1. The orthologue located on the chromosome is predicted to encode a 94-amino-acid protein that is 85% identical to B. subtilis AbrB. The hypothetical protein encoded on pXO1 is 41% identical to B. subtilis AbrB but missing 27 amino acid residues from the amino terminus compared to the B. subtilis protein. Deletion of the pXO1-encoded abrB orthologue did not affect toxin gene expression under the conditions tested. However, a B. anthracis mutant in which the chromosomal abrB gene was deleted expressed pagA earlier and at a higher level than the parent strain. Expression of a transcriptional pagA-lacZ fusion in the abrB mutant was increased up to 20-fold during early exponential growth compared to the parent strain and peaked in mid-exponential rather than late exponential phase. In contrast to the strong effect of abrB on pagA expression, lef-lacZ and cya-lacZ expression during early-log-phase growth was increased only two- to threefold in the abrB null mutant. Western hybridization analysis showed increased PA, LF, and EF synthesis by the mutant. As is true in B. subtilis, the B. anthracis abrB gene is negatively regulated by spo0A. Our findings tie anthrax toxin gene expression to the complex network of postexponential phase adaptive responses that have been well studied in B. subtilis. (+info)