Sequence Variability of pXO1-Located Pathogenicity Genes of Bacillus anthracis Natural Strains of Different Geographic Origin

Effect of Lyoprotective Agents on the Preservation of Survival of a Bacillus cereus Strain PBG in the Freeze-Drying Process

Lyophilization is a widely employed long-term preservation method in which the bacterial survival rate largely depends on the cryoprotectant used. Bacillus cereus strain PBC was selected for its ability to thrive in environments contaminated with arsenic, lead, and cadmium, tolerate 500 ppm of free cyanide, and the presence of genes such as ars, cad, ppa, dap, among others, associated with the bioremediation of toxic compounds and enterotoxins (nheA, nheB, nheC). Following lyophilization, the survival rates for Mannitol 2.5%, Mannitol 10%, and Glucose 1% were 98.02%, 97.12%, and 96.30%, respectively, with the rates being lower than 95% for other sugars. However, during storage, for the same sugars, the survival rates were 78.71%, 97.12%, and 99.97%, respectively. In the cake morphology, it was found that the lyophilized morphology showed no relationship with bacterial survival rate. The best cryoprotectant for the PBC strain was 1% glucose since it maintained constant and elevated bacterial growth rates during storage, ensuring that the unique characteristics of the bacterium were preserved over time. These findings hold significant implications for research as they report a new Bacillus cereus strain with the potential to be utilized in bioremediation processes.

New Research on the Bacillus anthracis Genetic Diversity in Siberia

Anthrax is a particularly dangerous infection of humans and ungulates caused by the Gram-positive spore-forming bacterium Bacillus anthracis. The highly monomorphic and clonal species B. anthracis is commonly divided into three main lineages, A, B, and C, which in turn are divided into several canSNP groups. We report here a phylogenetic analysis based on the whole-genome sequence (WGS) data of fifteen strains isolated predominantly in Siberia or Central and Southern Russia. We confirm the wide distribution of the cluster of strains of the B.Br.001/002 group, endemic to the Russian Arctic, which is also present in the steppe zone of Southern Siberia. We characterize additional branches within the major A.Br.001/002 polytomy comprising the A.Br.Ames and A.Br.Sterne lineages, one of which is identified in the Arctic.

Allelic Polymorphism of Anthrax Pathogenicity Factor Genes as a Means of Estimating Microbiological Risks Associated with Climate Change

Abstract

Climate change brings new risks of emergence of especially dangerous diseases. The paper reports the possibility of assessing the pathogenic potential of bacteria as demonstrated by studying the allelic polymorphism of anthrax bacterium pathogenicity factor genes, which is a prerequisite for assessing the associated microbiological risks. The allelic polymorphism of the capBCADE operon (capB, capC, capA, capD, and capE genes) encoding the capsule biosynthesis proteins of Bacillus anthracis, and the acpA and acpB genes encoding the expression regulators of this operon have been studied for the first time. A number of single nucleotide polymorphisms (SNPs) were described in the strains of the studied sample, including 5 SNPs in the capB gene, 3 in capC, 4 in capA, 14 in capD, 2 in capE, and 15 in acpB, as well as 7 SNPs and one insertion in the acpA gene. As a result, the sample has been divided into sequence types for each gene and 17 genotypes, which are combinations of the identified sequence types. In silico translation of the detected alleles of the studied genes revealed three isoforms of the CapB and CapA proteins, two isoforms of the CapC and CapE proteins, six isoforms of the CapD protein, five isoforms of the AcpA protein, and four isoforms in the AcpB protein. It has been demonstrated that the SNP in the 351A → G position of capC is a marker of A.Br.Aust94 group strains. Based on the results, A.Br.Vollum group strains were divided into two subgroups. The strains in the evolutionary lines B and C differed from the line A strains by the presence of an 853G → A SNP in the acpA gene. In addition, a previously unknown variable number tandem repeat (VNTR), has been found in the acpA gene and the possibility of using it for differentiating and genotyping of B. anthracis strains has been demonstrated.

Some Peculiarities of Anthrax Epidemiology in Herbivorous and Carnivorous Animals

Anthrax is an especially dangerous zooanthroponosis caused by the Gram-positive spore-forming bacterium Bacillus anthracis. A notable feature of this disease is the difference in susceptibility to it among different groups of animals. Anthrax primarily affects herbivorous ungulate mammals; they are easily infected, and their disease often leads to rapid, even sudden, death. However, predators and scavengers are extremely resistant to anthrax, and if they become infected, they usually become mildly ill. As the result of the increased sensitivity of ungulates to anthrax and the possibility of disease transmission from them to humans, most studies of anthrax have focused on the diagnosis, prevention, and treatment of infection in farm animals and humans. The issues of anthrax in other animals, such as predators, and the peculiarities of anthrax epidemiology in wild ungulates have not been sufficiently detailed in the literature. In this article, we provide a review of literature sources that describe the differential susceptibility to infection of various groups of animals to anthrax and some epidemiological features of anthrax in animals that are not the main hosts of B. anthracis.