title: Identification of an African Bacillus anthracis lineage that lacks expression of the spore surface-associated anthrose-containing oligosaccharide.
abstract: The surfaces of Bacillus anthracis endospores expose a pentasaccharide containing the monosaccharide anthrose, which has been considered for use as a vaccine or target for specific detection of the spores. In this study B. anthracis strains isolated from cattle carcasses in African countries where anthrax is endemic were tested for their cross-reactivity with monoclonal antibodies (MAbs) specific for anthrose-containing oligosaccharides. Unexpectedly, none of the isolates collected in Chad, Cameroon, and Mali were recognized by the MAbs. Sequencing of the four-gene operon encoding anthrose biosynthetic enzymes revealed the presence of premature stop codons in the aminotransferase and glycosyltransferase genes in all isolates from Chad, Cameroon, and Mali. Both immunological and genetic findings suggest that the West African isolates are unable to produce anthrose. The anthrose-deficient strains from West Africa belong to a particular genetic lineage. Immunization of cattle in Chad with a locally produced vaccine based on anthrose-positive spores of the B. anthracis strain Sterne elicited an anti-carbohydrate IgG response specific for a synthetic anthrose-containing tetrasaccharide as demonstrated by glycan microarray analysis. Competition immunoblots with synthetic pentasaccharide derivatives suggested an immunodominant role of the anthrose-containing carbohydrate in cattle. In West Africa anthrax is highly endemic. Massive vaccination of livestock in this area has taken place over long periods of time using spores of the anthrose-positive vaccine strain Sterne. The spread of anthrose-deficient strains in this region may represent an escape strategy of B. anthracis.
authors.affiliation: Swiss Tropical and Public Health Institute, CH 4002 Basel, Switzerland.
authors.forename: Marco
authors.initials: M
authors.lastname: Tamborrini
authors.forename: Mark
authors.initials: M
authors.lastname: Bauer
authors.forename: Miriam
authors.initials: M
authors.lastname: Bolz
authors.forename: Angaya
authors.initials: A
authors.lastname: Maho
authors.forename: Matthias A
authors.initials: MA
authors.lastname: Oberli
authors.forename: Daniel B
authors.initials: DB
authors.lastname: Werz
authors.forename: Esther
authors.initials: E
authors.lastname: Schelling
authors.forename: Jakob
authors.initials: J
authors.lastname: Zinsstag
authors.forename: Peter H
authors.initials: PH
authors.lastname: Seeberger
authors.forename: Joachim
authors.initials: J
authors.lastname: Frey
authors.forename: Gerd
authors.initials: G
authors.lastname: Pluschke
mesh_terms: D000349:Africa; D000606:Amino Sugars / Q000378:metabolism*; D000818:Animals; D000881:Anthrax / Q000382:microbiology / Q000662:veterinary*; D001408:Bacillus anthracis / Q000235:genetics / Q000378:metabolism*; D001426:Bacterial Proteins / Q000235:genetics / Q000378:metabolism; D002417:Cattle; D002418:Cattle Diseases / Q000382:microbiology*; D003847:Deoxyglucose / Q000031:analogs & derivatives* / Q000378:metabolism; D015964:Gene Expression Regulation, Bacterial; D009844:Oligosaccharides / Q000378:metabolism*; D013171:Spores, Bacterial / Q000235:genetics / Q000378:metabolism*
chemical_list: C504007:4,6-dideoxy-4-(3-hydroxy-3-methylbutanamido)-2-O-methylglucopyranose; D000606:Amino Sugars; D001426:Bacterial Proteins; D009844:Oligosaccharides; D003847:Deoxyglucose