Neonicotinoid compounds are usually considered harmless and eco-friendly in terms of their targeted toxicity compared to that of pyrethroids and phosphorus-containing pesticides. However, overuse of neonicotinoid insecticides resulted in the accumulation of its residuals or intermediates in soil and water, which consequently affected beneficial insects as well as mammals, yielding pollution and secondary risks. This review summarized the recent advances in neonicotinoid degrading microorganisms and their metabolic diversity, with the aim to address the urgent need for degrading these insecticides. These advances may facilitate the development of controllable and reliable technologies for efficiently transforming neonicotinoid insecticides into value-added products by synthetic biology and metagenomics.
Animals ; Neonicotinoids/metabolism* ; Insecticides/metabolism* ; Soil ; Environmental Pollution ; Metabolic Networks and Pathways ; Mammals/metabolism*

OBJECTIVEThe dermal absorption of Imidacloprid was studied to understand the effects of concentrations and skin reservoir on pesticide risk assessment in in vitro absorption studies.

METHODSBy using Franz diffusion cell and the transdermal barrier of viable Wistar rat abdomen skin or frozen ones, the imidacloprid content in the receptor fluid and skin was determined by LC/MS/MS method, and the absorption effects were compared between two concentrations of Imidacloprid solutions and two types of skin, respectively.

RESULTSAll percentages reported are % of applied dose. In vitro studies using viable skin, the Imidacloprid content in the receptor fluid of high and low concentration was 6.8%, 6.6% respectively; and 10.7%, 1.3% in skin, thus total absorption was 17.5% and 7.9%. And in vitro studies using both viable and frozen skin under the same concentration circumstances, the Imidacloprid content in the receptor fluid of viable and frozen skin was 6.6% and 0.7% respectively, in skin was 1.3% and 10.7%, and total absorption was 7.9% and 11.4%.

CONCLUSIONComparison of these in vitro results showed that either concentrations or skin reservoir had an effect on the dermal absorption. During 6h exposure, the high concentration in viable skin had the maximum dermal absorption value, which was the worst-case exposure estimate, also the best single estimate for pesticide risk assessment.

Administration, Cutaneous ; Animals ; Imidazoles ; pharmacokinetics ; In Vitro Techniques ; Male ; Neonicotinoids ; Nitro Compounds ; pharmacokinetics ; Rats ; Rats, Wistar ; Skin ; metabolism ; Skin Absorption

To produce high-affinity monoclonal antibodies against pesticide imidacloprid, we synthesized the haptens 1-[(6-Carboxylethylthio-3-pyridinyl) methyl] -N-nitro-imidazolidinimine (named as H1) and 1-[(6-Chloro-3-pyridinyl) methyl]-3-carboxylpropyl-N-nitro-2-imidazolidinimine (termed as H2). And then the haptens were coupled to bovine serum albumin (BSA) and ovalbumin (OVA) for immunogen (H1-BSA) and coating antigen (H2-OVA) respectively by NHS ester method. BALB/c mice were immunized with H1-BSA conjugate. We obtained two hybridoma cell lines 2F11/A9 and 2G6/G12 secreting antibody specific for imidacloprid from the conventional hybridoma technology. The result showed that the subtypes of obtained monoclonal antibodies were IgG3 and IgG1, respectively, and the titers of ascites were up to 1:128 000. The indirect competitive ELISA indicated the IC50 values of 5.3 and 28.3 ng/mL with detection limits of 1.1 ng/mL and 7.7 ng/mL, respectively. Two monoclonal antibodies had no apparent cross reactivity with six analogous compounds. Thus, two prepared monoclonal antibodies had a very high affinity and specificity, and it could be used to develop ELISA for rapid determination of imidacloprid residue and laid a solid foundation for research and development of products for immunoassay.
Animals ; Antibodies, Monoclonal ; biosynthesis ; Antibody Specificity ; Hybridomas ; metabolism ; Imidazoles ; immunology ; Insecticides ; immunology ; Mice ; Mice, Inbred BALB C ; Neonicotinoids ; Nitro Compounds ; immunology

OBJECTIVETo investigate how acetamiprid, a new insecticide, affects the activity of superoxide dismutase (SOD), catalase (CAT), and ATPase and the SOD isozyme patterns in two G bacteria, E. coli K12 and Pse.FH2, and one G+ bacterum, B. subtilis.

METHODSThe SOD, CAT, and ATPase specific activities of cell lysates were determined spectrophotometrically at 550 nm, 240 nm, and 660 nm, respectively, with kits A001, A016, and A007. SOD isozyme patterns were detected by native PAGE analysis.

RESULTSSOD and CAT activities in the tested bacteria increased significantly in a concentration-dependent manner after different concentrations of acetamiprid were applied. The activity of SOD in B. subtilis and Pse.FH2 was stimulated and reached the highest level after treatment with 100 mg/L acetamiprid for 0.5 h. For Pse.FH2, there was another stimulation of SOD activity after acetamiprid application for about 8.0 h and the second stimulation was stronger than the first. The stimulation by acetamiprid showed a relative lag for E. coli K12. Acetamiprid seemed to exhibit a similar effect on CAT activity of the two G bacteria and had an evident influence on ATPase activity in the three bacteria within a relatively short period. Only one SOD isozyme was detectable in Pse.FH2 and B. subtilis, while different isozyme compositions in E. coli could be detected by native PAGE analysis.

CONCLUSIONAcetamiprid causes a certain oxidative stress on the three bacteria which may not only elevate SOD and CAT activities but also generate new SOD isozymes to antagonize oxidative stress. However, this oxidative stress lasts for a relatively short time and does not cause a long-term damage.

Adenosine Triphosphatases ; metabolism ; Bacillus ; drug effects ; enzymology ; Bacteria ; drug effects ; enzymology ; Catalase ; metabolism ; Escherichia coli ; drug effects ; enzymology ; Insecticides ; pharmacology ; Isoenzymes ; metabolism ; Neonicotinoids ; Pseudomonas ; drug effects ; enzymology ; Pyridines ; pharmacology ; Superoxide Dismutase ; metabolism