What Is Anthrax?

Abstract

Anthrax has been feared for its high mortality in animals and humans for centuries. The etiologic agent is considered a potentially devastating bioweapon, and since 1876―when Robert Koch demonstrated that Bacillus anthracis caused anthrax―it has been considered the sole cause of the disease. Anthrax is, however, a toxin-mediated disease. The toxins edema toxin and lethal toxin are formed from protein components encoded for by the pXO1 virulence plasmid present in pathogenic B. anthracis strains. However, other members of the Bacillus cereus group, to which B. anthracis belongs, have recently been shown to harbor the pXO1 plasmid and produce anthrax toxins. Infection with these Bacillus cereus group organisms produces a disease clinically similar to anthrax. This suggests that anthrax should be defined by the exotoxins encoded for by the pXO1 plasmid rather than the bacterial species it has historically been associated with, and that the definition of anthrax should be expanded to include disease caused by any member of the B. cereus group containing the toxin-producing pXO1 plasmid or anthrax toxin genes specifically.

Genus-Wide Genomic Characterization ofMacrococcus: Insights into Evolution, Population Structure, and Functional Potential

“…For Macrococcus , ambiguous species boundaries may not seem immediately concerning, as members of the genus are often viewed as animal commensals (Mazhar et al, 2018); thus, taxonomic misidentifications may not be viewed as “high consequence” compared to other organisms plagued by taxonomic issues (e.g. anthrax-causing organisms within the Bacillus cereus group, botulinum neurotoxin-producing members of Clostridium ) (Smith et al, 2018; Bower et al, 2022). However, as more Macrococcus strains undergo WGS and more is learned about the pathogenic potential of these organisms in animals and humans, there may be a greater need to ensure that species are clearly defined (e.g., in clinical laboratory, diagnostic, or regulatory settings).…”

Pathogenic Bacilli as an Emerging Biothreat?

“…Moreover, at the patient’s home, work-related clothing and gear tested positive, which suggests that the bacteria could have been brought home from work locations. Interestingly, the clinical presentation of these metal workers with pulmonary infections was anatomically different from those of patients with classical inhalation anthrax [ 46 ]. The metal workers consistently had necrotizing and suppurative broncho-pneumopathy [ 44 ], while inhalational anthrax patients usually present with mediastinitis [ 13 ].…”

“…It is noteworthy that the Bacillus family members able to induce anthrax and anthrax-like diseases have been growing considerably over the last two decades [ 46 ]. At the same time, the nomenclature of the B. cereus group has been moving greatly by applying new genomic technologies to determine more accurately the B. cereus group species.…”

“…In the field of anthrax, for two decades the description of B. cereus biovar anthracis and B. cereus anthracis-like has potentially increased the size of this list. In 2017, the US Department of Health and Human Services (DHHS) added B. cereus biovar anthracis to the list of select agents and toxins [ 46 ], while other countries did not, or even did not have any select agent list rule. For example, B. cereus biovar anthracis is not on the select agent list (Microorganismes and toxines (MOT) rules) in France.…”

Prospect of using B. anthracis exotoxin in the design of anti-selective emergency preparations

“…This property can vary both in diverse types of microorganisms and in strains of the same species [13]. It was established that variable sporulation conditions, including the use of liquid or solid media, levels of nutrients and divalent cations, as well as pH and temperature of the sporulation medium, can affect the persistence properties of the resulting spores [14].…”