Eco-Genetic Structure of Bacillus cereus sensu lato Populations from Different Environments in Northeastern Poland

Abstract

The Bacillus cereus group, which includes entomopathogens and etiologic agents of foodborne illness or anthrax, persists in various environments. The basis of their ecological diversification remains largely undescribed. Here we present the genetic structure and phylogeny of 273 soil B. cereus s.l. isolates from diverse habitats in northeastern Poland, with samplings acquired from the last European natural forest (Białowieża National Park), the largest marshes in Europe (Biebrza National Park), and a farm. In multi-locus sequence typing (MLST), despite negative selection in seven housekeeping loci, the isolates exhibited high genetic diversity (325 alleles), mostly resulting from mutation events, and represented 148 sequencing types (131 STs new and 17 STs already described) grouped into 19 complexes corresponding with bacterial clones, and 80 singletons. Phylogenetic analyses showed that 74% of the isolates clustered with B. cereus s.l. environmental references (clade III), while only 11 and 15%, respectively, grouped with isolates of clinical origin (clade I), and B. cereus ATCC 14579 and reference B. thuringiensis (clade II). Predominantly within clade III, we found lineages adapted to low temperature (thermal ecotypes), while putative toxigenic isolates (cytK-positive) were scattered in all clades of the marsh and farm samplings. The occurrence of 92% of STs in bacilli originating from one habitat, and the description of new STs for 78% of the isolates, strongly indicate the existence of specific genotypes within the natural B. cereus s.l. populations. In contrast to the human-associated B. cereus s.l. that exhibit a significant level of similarity, the environmental isolates appear more complex. Thus we propose dividing B. cereus s.l. into two groups, the first including environmental isolates, and the second covering those that are of clinical relevance.

Determination of multiple antibiotic resistance patterns and indexing among metal tolerant -lactamase-producing Escherichia coli

“…Furthermore, AMR is increasing, and its spread between different bacterial strains in different habitats has been demonstrated (Drewnowska and Swiecicka, 2013;SVARM, 2006). Untreated drinking water coming from different sources contains coliforms including Esherichia coli.…”

The worldwide distribution of genetically and phylogenetically diverse Bacillus cereus isolates harbouring Bacillus anthracis‐like plasmids

“…Altogether 713 B. cereus soil isolates originating from Argentina (town park), Kazakhstan (town park), Kenya (car parks within Tsavo East National Park and Shimba Hills National Reserve) and Poland (two national parks and a farm in Northeastern Poland) were tested (for detail see http://onlinelibrary.wiley.com/doi/10.1111/1758-2229.12305/suppinfo; Supporting Information). Polish bacilli were isolated during previous investigation (Drewnowska and Swiecicka, ). In most cases, only one randomly chosen isolate from particular samples was used in the study.…”

Crystalliferous Bacillus cereus group bacteria from a Maryland hardwood forest are dominated by psychrotolerant strains

“…(). More recently, in a phylogenetic survey of the B. cereus group in northeastern Poland, Drewnowska and Święcicka () found that isolates from an old growth forest were primarily from Group VI, and the majority of these formed parasporal inclusions. As with our survey, very few isolates from forest soil were associated with Group IV, however, among crystal‐forming isolates collected from a farm and marshland in adjacent regions proportionally fewer isolates were associated with Group VI and more were associated with Group IV.…”