[Bacillus anthracis: causative agent of anthrax].
ABSTRACT Anthrax, an acute infectious disease of historical importance, is once again regaining interest with its use as a biological weapon. It is caused by B. anthracis, a Gram positive spore forming rod usually surrounded by a capsule and producing toxin. It occurs most frequently as an epizootic or enzootic disease of herbivores that acquire spores form direct contact with contaminated soil. Spores can survive for many years in soil. Animal vaccination programs have reduced drastically the disease in developed countries. In humans, the disease is acquired following contact with anthrax infected animals or their products. 3 types of anthrax infection can occur: cutaneous, inhalational and gastro intestinal. Cutaneous anthrax is the most common observed form. When germination occurs, replicating bacteria release toxin leading to hemorrhage, edema, necrosis and death. Full virulence of B. anthracis requires the presence of both antiphagocytic capsule and 3 toxin components (protective antigen, lethal factor and edema factor). Most naturally occurring anthrax strains are sensitive to penicillin but resistant to third generation cephalosporins. Post exposure prophylaxis is indicated to prevent inhalational anthrax.
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ABSTRACT: We present herein an efficient mass spectrometric method for the localization of the glycation sites of a model neoglycoconjugate vaccine formed by a construct of the tetrasaccharide side chain of the Bacillus anthracis exosporium and the protein carrier bovine serum albumin. The glycoconjugate was digested with both trypsin and GluC V8 endoproteinases, and the digests were then analyzed by MALDI-TOF/TOF-CID-MS/MS and nano-LC-ESI-QqTOF-CID-MS/MS. The sequences of the unknown peptides analyzed by MALDI-TOF/TOF-CID-MS/MS, following digestion with the GluC V8 endoproteinase, allowed us to recognize three glycopeptides whose glycation occupancies were, respectively, on Lys 235, Lys 420, and Lys 498. Similarly, the same analysis was performed on the tryptic digests, which permitted us to recognize two glycation sites on Lys 100 and Lys 374. In addition, we have also used LC-ESI-QqTOF-CID-MS/MS analysis for the identification of the tryptic digests. However, this analysis identified a higher number of glycopeptides than would be expected from a glycoconjugate composed of a carbohydrate-protein ratio of 5.4:1, which would have resulted in glycation occupancies of 18 specific sites. This discrepancy was due to the large number of glycoforms formed during the synthetic carbohydrate-spacer-carrier protein conjugation. Likewise, the LC-ESI-QqTOF-MS/MS analysis of the GluC V8 digest also identified 17 different glycation sites on the synthetic glycoconjugate.Biological Mass Spectrometry 10/2011; 46(10):993-1003. · 3.41 Impact Factor