Features of the response to subchronic low-dose exposure to copper oxide nanoparticles in rats.

Copper is an essential trace element for human health and, at the same time, a major industrial metal widely used both in its elemental form and in compounds. We conducted a dose-dependent assessment of the response of outbred albino male rats to subchronic low-dose exposure to copper oxide nanoparticles administered intraperitoneally at cumulative doses of 18 and 36 mg/kg during 6 weeks to exposure groups 1 and 2, respectively. We observed disorders at different levels of organization of the body in the exposed animals, from molecular to organismal. The observed decrease in the activity of succinate dehydrogenase in nucleated blood cells gave evidence of impaired bioenergetics processes. In view of the results of the metabolomics analysis, we assume mitochondrial damage and contribution of apoptotic processes to the pathology induced by copper poisoning. We also assume neurodegenerative effects based on the assessed morphological parameters of the nervous system, results of behavioral tests, and a decreased level of expression of genes encoding NMDA receptor subunits in the hippocampus. The hepatotoxic effect noted by a number of metabolomics-based, biochemical, and cytological indicators was manifested by the impaired protein-synthesizing function of the liver and enhanced degenerative processes in its cells. We also observed a nephrotoxic effect of nanosized copper oxide with a predominant lesion of proximal kidney tubules. At the same time, both doses tested demonstrated such positive health effects as a statistically significant decrease in the activity of alkaline phosphatase and the nucleated blood cell DNA fragmentation factor. Judging by the changes observed, the cumulative dose of copper oxide nanoparticles of 18 mg/kg body weight administered intraperitoneally approximates the threshold one for rats. The established markers of health impairments may serve as a starting point in the development of techniques of early diagnosis of copper poisoning.

Phylogeographical diversity of Anaplasma phagocytophilum in the Asian part of Russia based on multilocus sequence typing and analysis of the ankA gene.

Anaplasma phagocytophilum is a tick-transmitted bacterium that replicates in neutrophil granulocytes and elicits febrile disease in humans and animals; it is widely distributed in the Americas, Europe, Africa, and Asia. A. phagocytophilum is commonly regarded as a single species, but several genetic variants with distinct host distribution and geographical origin have been described. In a previous study, we used multilocus sequence typing (MLST) to characterize 25 A. phagocytophilum strains from Ixodes spp. ticks collected in the Asian part of Russia. The obtained concatenated sequences formed two separate clades reflecting their Asiatic origin and/or the vector species. As one of the clades was related to A. phagocytophilum strains from European voles and shrews, we here extended our analysis to seven samples from the northern red-backed vole Myodes rutilus and included 38 additional strains of Asiatic origin from Ixodes persulcatus, I. pavlovskyi, and their hybrids. Further, the ankA gene was sequenced in 59 A. phagocytophilum strains from ticks and voles. The Russian strains belonged to the two new MLST clusters 5 (38/70) and 6 (32/70), previously referred to as clades within clusters 1 and 3, respectively. The total number of sequence types (STs) found was 27 including 12 new STs. The ankA sequences were unique and formed two new clusters: cluster 8 (34/59) and cluster 10 (25/59). The concordance between MLST and ankA-based typing was 100%. This means that at least two distinct genetic groups of A. phagocytophilum circulate in the Asian Part of Russia whose reservoir hosts and transmission cycles have to be further elucidated.

Asian isolates of Anaplasma phagocytophilum: Multilocus sequence typing.

Anaplasma phagocytophilum is the bacterial agent of granulocytic anaplasmosis in humans and animals; it is widely distributed in Eurasia and North America and transmitted mainly by Ixodes ticks. Several approaches have been used to study genetic diversity in A. phagocytophilum, multilocus sequence typing (MLST) currently being the most reliable and comparable. The MLST method based on seven housekeeping loci, 2877 bp total length, has been used to create and maintain the MLST database available worldwide (https://pubmlst.org/aphagocytophilum/). Before this study, the database contained 150 sequence types (STs) and 418 isolates, 397 of them originating from Europe and 21 from the USA, with none from Asia. We typed 25 A. phagocytophilum isolated from Ixodes ticks collected in the Asian part of Russia and compared the results with the conventional 16S rRNA typing. Substantial variability in the primer binding sites was found, so we had to modify the original primers for six out of seven loci. None of the sequences obtained matched those from the database; 15 new STs and 39 new alleles were revealed. Russian isolates belonged to two clusters, cluster 1 (19 isolates) and 3 (6 isolates), in both of which they formed separate clades. For the first time, we found A. phagocytophilum isolates from Ixodes persulcatus and I. pavlovskyi to belong to cluster 3, previously containing only the strains from voles and shrews. Further research is needed to estimate the prevalence of two MLST clusters of A. phagocytophilum in ticks and vertebrate hosts in Asia.