The UN General Assembly has declared 2015 the International Year of Soils to raise awareness of the vital importance of soil, which is essential not only for food security and for cultivating plants for feed, fibre, fuel and medicinal products, but also for maintaining biodiversity as it hosts countless organisms. It plays a key role in storing and filtering water, in carbon and other nutrients cycling and performs other irreplaceable ecosystem functions. The Institute of Soil Biology of the CAS Biology Centre carries out biological research into many of those functions of soil in both natural and human–affected environments, including studies of the soil microstructure, soil organism communities and their dynamics and interactions and so on. Researchers at the Institute of Soil Biology focus, among other things, on the contribution of soil fungi to nitrous oxide emissions and on the production of methane. The latter is a potent greenhouse gas and a substantial part of atmospheric methane is produced by anaerobic microorganisms called Archaea found in the soil and in animal digestive tracts, while soil is also a significant methane sink. Research is also being concentrated on the characterization and risk assessment of antibiotic resistance-reservoirs in soil, which is connected with the massive use of antibiotics in the past five decades. Scientists examine ways of preventing the antibiotic resistance spreading in the environment through food chains as well as and on the role played by the soil microflora in those processes, as Doctor Dana Elhottová explains in the corresponding article. and Jana Olivová.
Large amounts of antibiotics and microplastics are used in daily life and agricultural production, which affects not only plant growth but also potentially the food safety of vegetables and other plant products. Fast detection of the presence of antibiotics and microplastics in leafy vegetables is of great interest to the public. In this work, a method was developed to detect sulfadiazine and polystyrene, commonly used antibiotics and microplastics, in vegetables by measuring and modeling photosystem II chlorophyll a fluorescence (ChlF) emission from leaves. Chrysanthemum coronarium L., a common beverage and medicinal plant, was used to verify the developed method. Scanning electron microscopy, transmission electron microscopy, and liquid chromatograph-mass spectrometer analysis were used to show the presence of the two pollutants in the samples. The developed kinetic model could describe measured ChlF variations with an average relative error of 0.6%. The model parameters estimated for the chlorophyll a fluorescence induction kinetics curve (OJIP) induction can differentiate the two types of stresses while the commonly used ChlF OJIP induction characteristics cannot. This work provides a concept to detect antibiotic pollutants and microplastic pollutants in vegetables based on ChlF.
The effects of different abiotic agents that may modulate the activity of an insect’s immune system are reviewed. These agents include insecticides, chitin synthesis inhibitors, juvenile hormone analogues, inert particles, antibiotics, heavy metals, radiation and miscellaneous substances. The significance of studying immunomodulation in insects treated with abiotic agents in relation to both insect control and insect-borne parasitic diseases and the link between immunomodulation in insects post-treatment with both abiotic and biotic agents are discussed., El-Sayed H. Shaurub., and Obsahuje seznam literatury
Autoimmune uveitis is a serious sightthreatening disease that in many cases fails to respond to conventional immunosuppressive or biological therapy. Experimental models used in research allow more detailed study of pathogenesis of the autoimmune process and testing new therapeutic strategies. Recent results show that infection can trigger autoimmune diseases, and some commensal microorganisms are essential in causing disease activity. The aim of this work was to assess the effect of broadspectrum antibiotics – combination of metronidazole and ciprofloxacin or metronidazole alone – on the intensity of intraocular inflammation in experimental autoimmune uveitis (EAU). EAU was induced in mouse strain C57BL/6J by interphotoreceptor retinoid-binding protein in complete Freund’s adjuvant and pertussis toxin. The grade of uveitis was assessed clinically and histologically in haematoxylin and eosin-stained tissues. Lymphocytes and macrophages were detected in cryosections using the immunoperoxidase method with antibodies. The therapy was commenced one week before EAU induction and continued throughout the experiment. In addition, metronidazole treatment was also started two weeks before EAU induction. Antibiotics significantly reduced the intensity of uveitis compared to the control group (P < 0.05). The effects of combination of ciprofloxacin and metronidazole and of metronidazole alone were similar when the therapy started one week before EAU induction (P < 0.05). Metronidazole commenced two weeks before EAU induction and throughout the experiment suppressed the intensity of EAU with even higher statistical significance (P < 0.0001). It can be assumed that the high protective effect of metronidazole on EAU intensity may be due not only to its antimicrobial effect, but also to its immunomodulatory activity
Environmental pollution by antibiotics poses a potential ecological risk to aquatic photosynthetic organisms. In the present study, toxic effects of erythromycin on PSI and PSII were investigated in cyanobacteria culture medium of Microcystis aeruginosa. The activity and electron transport of both photosystems were affected by erythromycin in a concentrationdependent manner. The quantum yield of PSII (YII) was reduced at 0.1 mg L-1 of erythromycin, while the quantum yield of PSI (YI) significantly decreased at concentration of 5-25 mg L-1. The decline of YII was accompanied by an increase of nonregulated energy dissipation (YNO). At 10 mg L-1 of erythromycin, YII decreased by 55%, while YNO increased by 18%. The decrease of YI induced by erythromycin was caused by donor-side limitation of PSI (YND). YND was markedly enhanced with elevated erythromycin concentration. At 10 mg L-1 of erythromycin, YI and YNA (PSI acceptor-side limitation) decreased by 8 and 82%, respectively, while YND rose by 314%. The quantum yield of cyclic electron flow increased significantly at 0.1-1 mg L-1 of erythromycin; it decreased but remained higher than that of the control at 5-25 mg L-1 of erythromycin. The contribution of cyclic electron flow to YI, and to linear electron flow rose significantly with the increasing erythromycin concentration. The maximum values of electron transport rates in PSII and PSI decreased by 71 and 24.3%, respectively, at 25 mg L-1 of erythromycin. Compared with the untreated control, the light saturation of PSII and PSI decreased significantly with increasing erythromycin concentration. We showed that concentrations of erythromycin >- 5 mg L-1 could exert acute toxicity to cyanobacteria, whereas the chronic toxicity caused by concentrations of ng or μg L-1 needs further research., C.-N. Deng, D.-Y. Zhang, X.-L. Pan., and Obsahuje bibliografii