Asad Amin

Fate of Antibiotics in Soil

An extensive amount of antibiotics is being used worldwide to enhance the health status, growth rate, milk, and meat production in dairy farms. In many aspects, the use of these veterinary antibiotics is crucial for the animals. But point of concern is that, animals don’t have enough ability to utilize these applied antibiotics, and it depends on the animal species and chemical composition of veterinary antibiotics. About 90% is obtained from the natural compounds like bacteria, fungi, and semisynthetic modifications and taken as “natural products,” and some are totally synthetic. Approximately 10–90% of the applied antibiotics are released in the form of urine and feces. The animal waste is used as fertilizer and exposed to the soil. Antibiotics present in manure are organic in nature and have the capability to bind with soil particles. These are many features that are affecting the fate of antibiotics in soil like the absorption and fixation rate of different antibiotics on the soil particles surfaces mainly depends on the soil pH, physico-chemical characteristics, climatic conditions, soil type, composition and quality of organic matter, soil texture, CEC, and iron oxide content and many other environmental factors. There are several procedures that are involved, including chemical nature, transport, leaching and runoff, sorption, plant uptake, and biodegradation that determines the fate of antibiotics in soil. The chemical nature determines the persistence of the antibiotic in soil and as a result of biodegradation or transformation different metabolites are produced that have different chemical composition and less risk will be associated with these metabolites than the actual antibiotic. Surface transport of antibiotics via runoff was attributed to delayed infiltration of water into the soil because of surface sealing through manure and particle bound transport. Surface runoff of antibiotics from animal waste spread the chemicals to the general water environment. Different plant organ and tissues have the ability to uptake and store the antibiotics, mostly in roots, cotyledons, and cotyledon petioles parts. Phytoremediation is potential of plants against the different antibiotics. In general, plants are used for the phytoremediation of toxic materials from soil in the past. But nowadays, phytoremediation (phytostabilization, phytotoextraction, phytovolatilization, and phytoaccumulation) emerging as a new technique was considered to be effective in elimination of antibiotic from planted soil. All these features help to determine the fate of antibiotic in soil.

Fate of Organic and Inorganic Pollutants in Paddy Soils

Paddy soils have a heterogenous nature, with complex physico-chemical interactions and varying soil characteristics. Paddy soils remain flooded and are considered as rich sources of nutrients for plant growth. The nutrient levels mostly depend on different management practices, such as fertilizer application, irrigation, and tillage, and the movement of nutrients in the soils. These paddy soils normally show less movement of applied nutrients out of the medium than other soils, because of stagnant water that reduces the mobility rate. Paddy soils can become polluted by anthropogenic practices such as the use of sewage wastewater; industrial wastewater containing heavy metals; fertilizers; and pesticides, and the leakage of petrochemicals. Some natural pollutants can be oxidized by microbial activity, but most pollutants do not undergo biotic and chemical degradation. Inorganic (heavy metals) and organic pollutants (polychlorinated biphenyls, polychlorinated dibenzodioxins, and polychlorinated dibenzofurans) are the major types of pollutants in paddy soils. The numerous organic and inorganic pollutants resulting from anthropogenic activities can remain for long periods in nature and can be transported over long distances. In particular, organic pollutants can be bioaccumulated and biomagnified, thus reaching high levels that can be dangerous for human wellbeing and biological communities. Inorganic pollutants such as the heavy metals Pb, Cr, As, Zn, Cd, Cu, Hg, and Ni cause hazards for human health, for plants, for animals, and for the fertility status of the soil. These heavy metals are common pollutants in paddy soil and they bioaccumulate; in this way the concentrations of these pollutants increase in living systems, owing to their retention rates being higher than their discharge rates in these systems. The fate of these pollutants depends on their bioavailability, degradation by microorganisms, adsorption, desorption, leaching, and runoff. The transport and degradation of these pollutants in paddy soils and groundwater results in contamination. The physico-chemical characteristics of the paddy soil framework; for example, the water content, soil organic matter, presence of clay, and pH, influence the sorption or desorption and degradation of pollutants and also influence leaching to the groundwater and runoff to surface waters. The translocation of natural pesticides in paddy soils depends upon the ionic or neutral behavior of the soil constituents, on the pesticides’ solubility in water, extremity on the substance, and the colloidal nature of the paddy soils.

Paddy Land Pollutants and Their Role in Climate Change

Climate change is one of the biggest concerns because its potential impact on human life is severe. The contribution ratio of CH4, CO2, and N2O to global warming would be high even if their emission rates are small. Paddy lands may become polluted by the aggregation of several pollutants, i.e., organic and inorganic fertilizers; discharges from the quickly extending industrial territories; use of manure, and organic solid waste; and wastewater irrigation system. Paddy lands are considered to be a major source of anthropogenic greenhouse gas (GHG) emissions through methanogenesis (a process of methane production), a microbial process that is strictly restricted to paddy fields. Overall 90% of rice land is at least temporarily flooded and produces GHGs at higher rates. The production of N2O in soils occurs during nitrification, denitrification, and microbiological processes. A positive relationship was found between the climate change and N fertilizer application with N2O emissions from paddy lands. The use of N fertilizer also stimulates and influences the CH4 emission flux between paddy land and atmosphere. The impact of biochar amendments on the CH4 emission expanded by 35.16–40.62% in paddy fields. It is of incredible concern worldwide that gaseous outflows from management of organic solid waste add to local and worldwide scale ecological procedures, for example, eutrophication, fermentation, and climate change. CH4 is generated from the disintegration of organic matter (OM) in anaerobic conditions by methanogens. Soil OM is the most well-known constraining element for methanogenesis in paddy fields. OM obtained from three primary sources: animal fertilizer, green manure, and crop deposits. The amendment of OM, for example, rice deposits and compost application, prompts expanding CH4 outflows because of anaerobic decay and results in climate change.

Burden of intestinal helminth infections among children of the Kashmir valley, India

S of the Problem: Cystic echinococcosis is a worldwide parasitic zoonosis caused by the larval stage of Echinococcus granulosus. Current chemotherapy against this disease is based on benzimidazoles (BZMs). However, BZM treatment results in a low cure rate and causes side effects. Therefore, new treatment options are needed. The antidiabetic drug glibenclamide (Glb) is a second-generation sulfonylurea receptor inhibitor that has been shown to be active against protozoan parasites. The purpose of this study is to investigate the in vitro and in vivo pharmacological effects of Glb against the larval stage of E. granulosus. Methodology & Theoretical Orientation: Viable protoscoleces and metacestodes were cultured in vitro with different concentrations of Glb and/or ABZSO and mortality was calculated daily. Subsequently, E. granulosus-infected mice were orally treated with Glb and/or ABZ daily for 60 days. The hydatid cysts collected from the animals were weighed and analyzed by SEM. Findings: The in vitro Glb activity on both protoscoleces and metacestodes was dependent on the concentration. In addition, the combination of Glb and ABZSO had a greater effect on metacestodes than each drug alone. Likewise, a reduction of the cyst weight was also found after administration of Glb to infected mice. However, Glb + ABZ combined treatment not shown to be more effective than Glb monotherapy. Our results also demonstrated mitochondrial membrane depolarization and increase of Ca+2 intracellular levels in Glb-treated protoscoleces. Moreover, the intracystic drug accumulation, the competition of Glb for 1-NPN binding site in protoscoleces, and the bioinformatic analysis using the available E. granulosus genome, suggest the presence of genes encoding receptor and transporters of sulfonylureas in the parasite. Conclusion & Significance: Glb shows anthelmintic effect on E. granulosus larval stage. Further studies are needed to fully investigate the mechanism involved in the therapeutic response of the parasite to this sulfonylurea.