Which of the following is true regarding anthrax ?
M' Fadyean reaction shows capsule
Humans are usually resistant to infection
Less than 100 spores can cause pulmonary infection
All
Ans. is 'a' i.e., M' Fadyean reaction shows capsule; 'b' i.e., Humans are usually resistant to infection; 'c' i.e., Less than 100 spores can cause pulmonary infection . M' Fadyean's reaction represents the capsular material and is characteristic of the anthrax bacillus. . "Man is relatively resistant to infection with B. anthracis". - Green wood 16th/e 226 . In animal studies, it has been shown that aerosolized anthrax -- 10,000 spores required to produce lethal disease. However, it has been suggested that as few as one to three spores may be adequate to cause disease in some setting. - Harrison 17thie 1344 . Spores are of same width as the bacillary body so that they do not cause bulging of the vegetative cell (in contrast the clostridia have bulging spores). . For laboratory diagnosis, specimens to be examined are fluid or pus from a local lesion, blood or sputum. Stained smears often show chains of large gram positive rods.