Investigation into Bacillus anthracis Spore in Soil and Analysis of Environmental Parameters Related to Repeated Anthrax Outbreak in Sirajganj, Bangladesh

The study was conducted for the isolation and detection of Bacillus anthracis spores from soil collected from Sirajganj district (a north-western district of Bangladesh), and to assess the parameters that may relate to the repeated anthrax outbreak. A total of 48 soil samples were collected from the study area during January 2012 to November 2012. Endospores were extracted from soil and the Bacillus anthracis was identified using conventional bacteriological, biochemical and sensitivity test against Penicillin-G. The viable B. anthracis spores could be detected from 14 (29.17%) soil samples. The mean pH of anthrax positive soil was weakly acidic (6.38±0.15), indicating that a suitable pH range for anthrax spore was present in the soil of Sirajganj. During the disease outbreak period (May and June) the average temperature of this area was 32°C and the average rainfall was 158 mm and 90 mm, respectively. Although the temperature variation had no significant influence on the occurrence of anthrax spore, rainfall was found to be significant.