In defence of Bacillus thuringiensis, the safest and most successful microbial insecticide available to humanity—a response to EFSA. Issue 7 (22nd June 2017)

• Record Type: Journal Article
• Authors: Raymond, Ben; Federici, Brian A.
• Is Part Of: FEMS microbiology ecology. Volume 93:Issue 7(2017:Jul.)
• Publication Date: 2017-06-22
• Subjects: Bacillus cereus group -- biocontrol -- biopesticide -- food safety -- phylogeny; Microbial ecology -- Periodicals; Microbiology -- Periodicals; 579.17
• DOI: 10.1093/femsec/fix084
• Languages: English
• ISSNs: 0168-6496

Abstract

Abstract: The Bacillus cereus group contains vertebrate pathogens such as B. anthracis and B. cereus and the invertebrate pathogen B. thuringiensis (Bt) . Microbial biopesticides based on Bt are widely recognised as being among the safest and least environmentally damaging insecticidal products available. Nevertheless, a recent food-poisoning incident prompted a European Food Safety Authority review which argued that Bt poses a health risk equivalent to B. cereus, a causative agent of diarrhoea. However, a critical examination of available data, and this latest incident, provides no solid evidence that Bt causes diarrhoea. Although relatively high levels of B. cereus -like spores can occur in foods, genotyping demonstrates that these are predominantly naturally occurring strains rather than biopesticides. Moreover, MLST genotyping of >2000 isolates show that biopesticide genotypes have never been isolated from any clinical infection. MLST data demonstrate that B. cereus group is heterogeneous and formed of distinct clades with substantial differences in biology, ecology and host association. The group posing the greatest risk (the anthracis clade) is distantly related to the clade containing all biopesticides. These recent data support the long-held view that Bt and especially the strains used in Bt biopesticides are very safe for humans. Abstract : This article critically examines the available evidence on whether Bacillus thuringiesis, a species commericially important in biocontrol, is capable of infecting vertebrates.