Vol 16, No 3 (2018)
- Year: 2018
- Published: 15.10.2018
- Articles: 7
- URL: https://journals.eco-vector.com/ecolgenet/issue/view/473
- DOI: https://doi.org/10.17816/ecogen163
Genetic basis of ecosystems evolution
Mechanisms of bacterial multiresistance to antibiotics
Abstract
Multiple drug resistance (MDR) to widening range of antibiotics emerging in increasing variety of pathogenic bacteria is a serious threat to the health of mankind nowadays. This is partially due to an uncontrolled usage of antibiotics not only in clinical practice, but also in various branches of agriculture. MDR is affected by two mechanisms: (1) accumulation of resistance genes as a result of intensive selection caused by antibiotics, and (2) active horizontal transfer of resistance genes. To unveil the reasons of bacterial multiresistance to antibiotics, it is necessary to understand the mechanisms of antibiotics action as well as the ways how either resistance to certain antibiotics emerge or resistance genes accumulate and transfer among bacterial strains. Current review is devoted to all these problems.
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Haplotypic diversity of mosquitoes of the genus Anopheles (Diptera, Culicidae) of North Vietnam
Abstract
Background. Malaria in the territory of North Vietnam remains an actual problem. The species composition of mosquitoes of the genus Anopheles – the main vectors of malaria and the density of their populations – has a critical impact on the likelihood of the epidemic.
Materials and methods. We analyzed the variability of the BOLD fragment of the mitochondrial cox1 gene in a sampling set of Anopheles mosquitoes from the North Vietnam. Results. We found mosquitoes belonging to the species complexes: Anopheles sinensis, Anopheles vagus and Anopheles barbirostris. Nucleotide variability within the complexes does not exceed 2%. The differentiation into subspecies within the species complexes was not found.
Conclusion. The most common species of the genus Anopheles of North Vietnam is Anopheles sinensis — the main malaria vector. We predict the success of local transmission of malaria in this region in the case of malaria emergence.
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Genetic toxicology
Bacterial DNA damage effectors in host cells
Abstract
The microbiota has a significant, and sometimes decisive, effect on the host's homeostasis. The results of recent metagenomic studies confirm the importance of microbiota in maintaining health or its impact on the development of acute, chronic and neoplastic diseases. One of the important aspects of microbiota exposure is the ability of many bacterial species to induce mutations or modulate a mutation process in the cells of the host organism. This review summarizes the main experimental data revealing various mechanisms of genotoxic action of a bacterial microbiota, including direct damage to the DNA structure, induction of oxidative stress, delay in replication, and a decrease in repair efficiency. It is emphasized that bacteria use different strategies to ensure their own survival and replication, including. by suppressing the repair of host cell DNA, by promoting the survival of infected cells, despite the presence of DNA damage therein.
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The comparative analysis of effectiveness of barley intercalar and apical meristems applying for bioindication of lead influence genotoxicity
Abstract
Background. Lead is the one of the major pollutants in natural and artificial ecosystems, but mechanisms of it influence on the plant organism still aren’t completely clear. With the growing industrial pollution of the environment, and in particular, arable lands, the methods of bioindication of chemical compounds influence on the plant organism are obtained a big significance in modern biology. The cytogenetic analysis is well proven method for assessment of the environmental stress. The current research was devoted to the analysis of the cytogenetic aberrations bounds with the biometric and biochemical indexes and productivity of barley plants, which were grown on the lead polluted soil at terms of the vegetative experiment. An estimation of the comparative effectiveness of the barley plants intercalary and apical meristem applying for the indication of the lead toxicity are presented in the current work.
Materials and methods. The vegetative experiment was carried on the barley plants variant Zazerskii 85 on the podzol loamy soil with the inserting of the nutrient elements and lead in the different concentrations at the form of salts. Plants were grown in the pots with the capacity of 5 kg by the standard methodic. For the cytogenetic analysis samples were taken on V1 phase of the ontogenesis and fixed in the acetyl alcohol. Temporary squashed preparations was stained with the acetoorsein and examined by the microscope. Frequencies of the cytogenetic anomalies and aberrant cells were scored.
Results. It was shown, that forms of dose curves of the frequencies of the aberrant cells at the intercalary and apical meristems are compatible and changes of the mitotic index aren’t significant. A major part of the cytogenetic anomalies are bound with the division spindle breaches. A suitability of the apical and intercalary meristems for the assessment of the heavy metals influence on the agricultural plants was proven.
Conclusions. On the base of collected data the cytogenetic analysis can be recommended as the reliable tool for the assessment of the industrial pollution consequences for the agricultural ecosystems and for the researching of the mechanisms of the living objects response to the environmental stress. For the heavy metals influence monitoring the intrecalar meristems is preferable as more sensitive, but for plants productivity prognosis the apical meristems is suitable.
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DNA damage induction in bone marrow cells of mice after farnesenes and 2,5-dimethylpyrazine sniffing
Abstract
Background. Pheromones are an important regulatory link of synecological contacts in numerous animal species. Chemo-signaling participates in establishing of population social structure, it regulates different types of behavior, changes hormonal state and maturation rate, etc. It also can affect the genetic material expression and integrity.
Material and methods. Groups of adult males of CBA/Lac/Sto/Rap strain were exposed to volatile chemosignals (mixture of α- and β-farnesenes or 2,5-dime thylpyrazine) for 2 or 24 hours. Bone marrow cells were prepared for single cell gel electrophoresis (comet assay test). Content of DNA in comet cells were analyzed. In case of 24 hours exposure bone marrow cells were fixed also for ana-telophase analysis.
Results. It is shown that exposures with farnesenes or 2,5-DMP both damage genetic material of bone marrow cells. It also followed by induction of mitotic aberration frequency. Simultaneous exposure with all chemosignals does not increase damaging effect.
Conclusion. Chemosignals which serve as stress-pheromones in mice decrease also the integrity of genetic material in bone marrow cells of recipients. It could be a mechanism of pheromonal impact on density and space-genetic structure of mouse populations.
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Evaluation of mutagenic and antimutagenic potential of stem bark aqueous extracts of eight trees by the bacterial reverse mutation assay
Abstract
Stem bark aqueous extracts of eight woody plants Brachychiton populneus, Ceiba pentandra, Bombax malabaricum, Chorisia speciosa, Albizia lebbeck, Bauhinia variegata, Kigelia africana and Pinus halepensis were tested for their mutagenic and antimutagenic potential in the Ames test with Salmonella typhimurium strains TA98 and TA100. The aqueous extracts were neither toxic nor mutagenic in S. typhimurium tester strains. All of the tested extracts showed detectable antimutagenic effect towards the direct acting mutagens 2-nitrofluorene (2-NF) in TA98 as well as sodium azide in TA100. The extract from Kigelia africana was the most effective in reducing the mutagenicity caused by the direct mutagen 2-NF in the TA98 with 85.42% inhibition rate. A. lebbeck stem bark extract demonstrated the highest antimutagenic activity reducing the base substitution mutations rate for strain TA100 by 94.66% in pre-incubation assay. The results obtained showed that the stem bark aqueous extracts tested can protect cells against induced gene mutations.
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Human ecological genetics
Mutations in tumor suppressor genes and their relationship with phenotypic features of breast cancer in young age women
Abstract
Background. Breast cancer (BC) is the most common oncological disease in women in the world. The aim of study is to investigate the frequencies of mutations in BRCA1 5382insC (rs80357906), CHEK2 1100delC (rs555607708) and BLM c.1642 C>T (rs200389141) genes and their relationship with the phenotypic features of BC in 104 young age women.
Materials and methods. We studied 104 young age women with breast cancer. Typing of mutations BRCA1 5382insC, CHEK2 1100delC and BLM c.1642 C>T genes were performed by real-time PCR followed by melting analysis.
Results. The BRCA1 5382insC mutation was detected in 9.6% of BC patients. The BRCA1 5382insC mutation was correlated with the lack of expression of estrogen receptors (χ2 = 18.48, d(f) = 1, p < 0.0001), the HER2/neo tumor receptor (χ2 = 5.61, d(f) = 1, p < 0.02). The BRCA1 5382insC mutation was more often in the “triple negative” BC (χ2 = 17.42, d(f) = 3, p < 0.001). Luminal A subtype of disease was observed the predominantly in non-carriers of the mutation BRCA1 5382insC (sporadic breast cancer). The founder mutations in the CHEK2 1100delC and BLM c.1642 C>T genes were absent in young age women with BC.
Conclusion. Our results confirm the high significance of detecting the BRCA1 rs80357906 mutation in young age women with BC for optimization of treatment tactic and for early diagnosis of BC.
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