Current Understanding on the Biology of Bacillus Anthracis and Its Pathophysiology: A Critical Appraisal

Mahendra Pal^1, , Tesfaye Rebuma², Alemayehu Bekele³, Milad Badri⁴, Ravindra Zende⁵ and Aishwarya Nair⁵

¹Narayan Consultancy of Veterinary Public Health and Microbiology, B-103, Sapphire Lifestyle, Bharuch - 392 012, Gujarat, India

²Shaggar City Administration, Sebeta Sub-City Agricultural office, Sebeta, Oromia Region, Ethiopia

³Wallaga University, School of Veterinary Medicine, Department of Clinical Studies, Nekemte, Oromia, Ethiopia

⁴Medical Microbiology Research Center, Qazvin University of Medical Sciences, Qazvin, Iran

⁵Department of Veterinary Public Health and Epidemiology, College of Veterinary Science, Parel, Mumbai, India

Cite this paper:
Mahendra Pal, Tesfaye Rebuma, Alemayehu Bekele, Milad Badri, Ravindra Zende and Aishwarya Nair. Current Understanding on the Biology of Bacillus Anthracis and Its Pathophysiology: A Critical Appraisal. American Journal of Microbiological Research. 2025; 13(3):76-83. doi: 10.12691/ajmr-13-3-6

Abstract

Bacillus anthracis, the causative agent of anthrax, is a Gram-positive bacterium that poses serious concerns for public health and biodefense and capable of forming resilient spores enables prolonged environmental survival, and it can infect hosts through cutaneous, inhalational, gastrointestinal or injection routes. The pathogenicity of bacteria is primarily attributed to its poly-D-glutamic acid capsule and a tripartite exotoxin complex consisting of protective antigen, edema factor and lethal factor, which collectively facilitate immune evasion and systemic spread. While herbivores are particularly vulnerable, all warm-blooded animals, including humans, are susceptible to infection. Natural outbreaks are frequently associated with contaminated soil, making geographic and ecological surveillance essential in endemic regions. Vaccination, particularly with protective antigen (PA)-based vaccines, is the most effective preventive strategy, although challenges in vaccine tolerance and accessibility remain. Recent advances in molecular epidemiology and genomic sequencing have enhanced the tracking of outbreak sources and strain variation. Prompt administration of antimicrobial therapy and monoclonal antibody use are critical for successful treatment. Additionally, proper carcass disposal, environmental decontamination, and active surveillance are crucial for breaking the transmission cycle and managing outbreaks. Understanding the molecular pathogenesis, host susceptibility and immunological responses is essential for advancing diagnostics, therapeutics and control measures.

Keywords:
Bacillus anthracis Biodefense Pathophysiology Spore Virulence factors Zoonosis

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