Genetic Diversity of Australian Bacillus anthracis Isolates Revealed by Multiple-Locus Variable-Number Tandem Repeat Analysis

Abstract

Outbreaks of anthrax occur sporadically in Australia and most commonly in the “anthrax belt”, a region which extends from southern Queensland through the centre of New South Wales and into northern Victoria. Little is known about the epidemiological links between Bacillus anthracis isolates taken from different outbreaks and the diversity of strains within Australia. We used multiple-locus variable-number tandem repeat analysis employing 25 markers (MLVA25) to genotype 99 B. anthracis isolates from an archival collection of Australian isolates. MLVA25 genotyping revealed eight unique genotypes which clustered within the previously defined A3 genotype of B. anthracis. Genotyping of B. anthracis strains from outbreaks of disease in Victoria identified the presence of multiple genotypes associated with these outbreaks. The geographical distribution of genotypes within Australia suggests that a single genotype was introduced into the eastern states of Australia, followed by the spread and localised differentiation of the pathogen (MLVA25 genotypes MG1-MG6) throughout the anthrax belt. In contrast, unexplained occurrences of disease in areas outside of this anthrax belt which are associated with different genotypes, (MLVA25 genotypes MG7 and MG8) indicate separate introductions of B. anthracis into Australia.

Modelling climate change impacts on the spatial distribution of anthrax in Zimbabwe

“…The bioclimatic variables for the current climate consisting of temperature and precipitation related factors and their derivatives were freely downloaded from the world climate data website at ( http://worldclim.org/version2.1 ). The bioclimatic variables were based on the Beijing Climate Centre Climate System Model for the current and future climate scenarios i.e., 4.5 and 8.5 Representative Concentration Pathways (RCP) [ 42 ]. The term “representative” means that each RCP provides only one of many possible scenarios that result in a particular radiative forcing.…”

“…org/ versi on2.1). The bioclimatic variables were based on the Beijing Climate Centre Climate System Model for the current and future climate scenarios i.e., 4.5 and 8.5 Representative Concentration Pathways (RCP) [42]. The term "representative" means that each RCP provides only one of many possible scenarios that result in a particular radiative forcing.…”

Identification of the molecular characteristics of Bacillus anthracis (1982-2020) isolates in East Indonesia using multilocus variable-number tandem repeat analysis

“…Conventional PCR was conducted for chromosomal and plasmid marker detection of B. anthracis following a previous study [ 33 ]. Three pairs of primers were used for the chromosomal gene detection (152 bp), the lethal factor virulence gene located on pXO1 (385 bp), and the capsule gene located on pXO2 (264 bp) [ 20 ]. Primer concentration was 18 pmoL.…”

“…Primer concentration was 18 pmoL. The three pairs of primers used were chromosomal detection (152 bp), 385 bp segment of the lethal factor virulence gene on pXO1, and a 264 bp segment of a capsule gene on pXO2 [ 20 ]. The Master Mix PCR was prepared inside a clean PCR suite.…”

Bacillus anthracis Phylogeography: New Clues From Kazakhstan, Central Asia

“…Each of these lineages shows some level of geographic association, often blurred by numerous more or less successful export events. For instance, strains from group Australia94 were first identified in Australia but the group is also predominant in East Anatolia and South Caucasus ( Khmaladze et al, 2014 ; Sahin et al, 2018 ; Eremenko et al, 2021 ), and Australia is believed to have been contaminated in 1847 via bones imported from India and used as fertilizer ( Davies and Harvey, 1972 ; Van Ert et al, 2007 ; Barro et al, 2016 ; Muller et al, 2020 ). The Neolithic model predicts that world history will allow to infer dating points along the phylogeny, in addition to the WNA branching point from Europe toward North America or the “Australia94” export to Australia.…”