Abstract

Introduction: The spore form of Bacillus anthracis represents a threat to livestock in the Kars region of Northern Turkey due to its longevity and ability to infect grazing animals. The burial of untreated, anthrax infected, animal carcasses have resulted in anthrax “hotspots”. To reduce the risk posed by these sites a decontamination strategy based on Peracetic acid (PAA) and germinants which targets the pathogen but causes minimal damage to the environment has been developed. Results: In laboratory studies, the ability of PAA to inactivate spores of B.anthracis Sterne across a range of contact times and conditions has been demonstrated. Biocidal activity was enhanced by the presence of the germinants L-Alanine (100mM) and inosine (5mM). Laboratory based microcosm studies using obtained from animal burial sites and inoculated with an additional 104 spores/gram of B.anthracis Sterne revealed a two stage decontamination strategy of germinants followed 1 hr later by 5,000 ppm of PAA to be the most effective, resulting in a 4.7 log10 reduction in confirmed B.anthracis spore numbers at 24 hours. This strategy was subsequently employed to treat two anthrax burials sites in Turkey. Biocide and germinants were delivered using two commercially available spraying devices. Treatment of both sites resulted in a reduction in B.anthracis spore numbers. Unfortunately the relatively low numbers of B.anthracis spores in the treated soil (11-264 spores/gram) and restrictions as to the volumes of PAA which we could deliver due to concerns over potential environmental damage, made it difficult to draw any firm conclusions as to the efficacy of the approach. At the levels of PAA employed the biocide had degraded to undetectable levels in under 2 hours suggesting that higher volumes of agent could be used. Conclusions: The combination spore germinants and PAA proved to be an effective means of reducing B.anthracis spores numbers in soil. Further field trials are required to confirm the efficacy of this approach