Caption: Bacillus anthracis - vegetative stage. Bacillus anthracis is a Gram-positive, encapsulated, spore-forming, zoonotic, rod prokaryote. It most commonly occurs in wild and domestic lower vertebrates (cattle, sheep, goats, and other herbivores), but it can also occur in humans when they are exposed to infected animals or tissue from infected animals. In humans it causes the acute infectious disease, anthrax which can lead to septicemia and death if left untreated. Bacillus anthracis spores can live in the soil for many years, and humans can become infected with anthrax by handling products from infected animals such as animal hides or by inhaling anthrax spores from contaminated animal products or other sources. In humans anthrax can kill by two toxins and an antigen factor being produced by the bacterium (edema toxin, lethal toxin, capsular antigen). Human anthrax has three major clinical forms: cutaneous, inhalation, and gastrointestinal. Cutaneous anthrax is a result of introduction of the spore through the skin; inhalation anthrax through the respiratory tract; and gastrointestinal anthrax by ingestion.
Magnification*: x2,200
Type: SEM
Copyright 2001 Dennis Kunkel Microscopy, Inc.
Keywords: 21185B,bacteria,Bacillus anthracis,rod,encapsulated,spore forming,bacilli,bacillus,soil bacterium,prokaryote,division,anthrax,vegetative,anthrax spore,anthrax spores,bacterial pathogen,infection,human disease,animal disease,zoonoses,zoonotic microorganism,Gram-positive,Woolsorter's disease,inhalation anthrax,cutaneous anthrax,speticemia,edema toxin,lethal toxin,capsular antigen,SEM