Screening for anthrax occurrence in soil of flooded rural areas in Poland after rainfalls in spring 2010

Introduction and objective. Anthrax spores remain viable and infectious in soil for decades. Flood water can percolate towards the surface the spores buried in soil. Moreover, the flood water might transport spores to areas previously unaffected. After the water recedes the spores located on the surface of the ground can be consumed by grazing animals and cause outbreaks of anthrax. Materials and method. Soil samples were collected in areas of Poland most affected by floods in 2010 (Lubelskie, Swietokrzyskie, Podkarpackie and Mazowieckie provinces). After heating with the aim to kill vegetative forms of bacteria, the samples were cultured on PLET agar and the resulted colonies were investigated in terms of motility and presence of anthrax specific chromosomal (SG-749, plcR) and plasmid markers (capB, pagA). Results. In total, 424 spore-forming, aerobically growing isolates were collected from the tested soil samples. Eighty-nine of them were non-motile. All the isolates were negative in PCR for anthrax specific chromosomal and plasmid markers. Conclusions. Spores of B. anthracis that could be related to risk of anthrax outbreaks were not detected in soil samples tested in this study. The negative results presented may not be proof that Poland is country free of anthrax. The results, however, may suggest a relatively low risk of anthrax outbreaks being triggered in the sampled areas.