Pub Date : 2019-09-02DOI: 10.1080/03601234.2019.1670480
Brittany Rapp
{"title":"Nano-Biopesticides Today and Future Perspectives","authors":"Brittany Rapp","doi":"10.1080/03601234.2019.1670480","DOIUrl":"https://doi.org/10.1080/03601234.2019.1670480","url":null,"abstract":"","PeriodicalId":15670,"journal":{"name":"Journal of Environmental Science and Health, Part B","volume":"54 1","pages":"801 - 802"},"PeriodicalIF":0.0,"publicationDate":"2019-09-02","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"85398120","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2019-08-20DOI: 10.1080/03601234.2019.1653735
T. Vasić, Uroš D. Vojinović, Suzana Žujović, V. Krnjaja, S. Živkovic, J. Marković, M. Stević
Abstract Sensitivity of 24 isolates of Colletotrichum destructivum O’Gara, collected from alfalfa plants in Serbia, to eight selected fungicides, was investigated in this study. Molecular identification and pathogenicity test of isolates tested were also performed. Fungicide sensitivity was evaluated in vitro, using mycelial growth assay method. All isolates exhibited significant pathogenicity, causing necrosis at the alfalfa seedling root tips two days after inoculation. Using the primer pair GSF1-SR1 and by comparing the amplified fragments of the tested isolates with the marker (M), the presence of the amplicon of the expected size of about 900 bp was determined for all isolates. The isolates tested in this study showed different sensitivity towards fungicides in vitro. Mycelial growth was highly inhibited by QoI (quinone outside inhibitors) fungicide pyraclostrobin (mean EC50=0.39 µg mL−1) and by DMI (demethylation-inhibiting) fungicide tebuconazole (mean EC50=0.61 µg mL−1), followed by azoxystrobin (mean EC50=2.83 µg mL−1) and flutriafol (mean EC50=2.11 µg mL−1). Multi-site fungicide chlorothalonil and MBC (methyl benzimidazole carbamate) fungicide thiophanate-methyl evinced moderate inhibition with mean EC50=35.31 and 62.83 µg mL−1, respectively. Thirteen isolates were sensitive to SDHI (succinate dehydrogenase inhibitors) fungicide boscalid and fluxapyroxad, (mean EC50=0.49 and 0.19 µg mL−1, respectively), while the rest of isolates were highly resistant.
摘要研究了从塞尔维亚苜蓿中采集的24株炭疽菌(Colletotrichum destructivum O’gara)对8种选定杀菌剂的敏感性。并对分离株进行了分子鉴定和致病性试验。采用菌丝生长测定法体外评价杀菌剂的敏感性。所有分离株均表现出显著的致病性，接种2天后引起苜蓿幼苗根尖坏死。利用引物对GSF1-SR1，并将扩增片段与标记物(M)进行比较，确定所有分离株均存在预期大小约900 bp的扩增子。本研究检测的菌株对体外杀菌剂的敏感性不同。QoI(醌外源抑制剂)杀菌剂吡唑菌酯(平均EC50=0.39 μ g mL - 1)和DMI(去甲基化抑制)杀菌剂戊康唑(平均EC50=0.61 μ g mL - 1)对菌丝生长有高度抑制作用，其次是偶氮菌酯(平均EC50=2.83 μ g mL - 1)和氟triafol(平均EC50=2.11 μ g mL - 1)。多位点杀菌剂百菌清和MBC(甲基苯并咪唑氨基甲酸酯)杀菌剂噻吩-甲基具有中等抑制作用，平均EC50分别为35.31和62.83µg mL−1。13株菌株对SDHI(琥珀酸脱氢酶抑制剂)杀菌剂boscalid和fluxapyroxad敏感(平均EC50分别为0.49和0.19µg mL−1)，其余菌株高度耐药。
{"title":"In vitro toxicity of fungicides with different modes of action to alfalfa anthracnose fungus, Colletotrichum destructivum","authors":"T. Vasić, Uroš D. Vojinović, Suzana Žujović, V. Krnjaja, S. Živkovic, J. Marković, M. Stević","doi":"10.1080/03601234.2019.1653735","DOIUrl":"https://doi.org/10.1080/03601234.2019.1653735","url":null,"abstract":"Abstract Sensitivity of 24 isolates of Colletotrichum destructivum O’Gara, collected from alfalfa plants in Serbia, to eight selected fungicides, was investigated in this study. Molecular identification and pathogenicity test of isolates tested were also performed. Fungicide sensitivity was evaluated in vitro, using mycelial growth assay method. All isolates exhibited significant pathogenicity, causing necrosis at the alfalfa seedling root tips two days after inoculation. Using the primer pair GSF1-SR1 and by comparing the amplified fragments of the tested isolates with the marker (M), the presence of the amplicon of the expected size of about 900 bp was determined for all isolates. The isolates tested in this study showed different sensitivity towards fungicides in vitro. Mycelial growth was highly inhibited by QoI (quinone outside inhibitors) fungicide pyraclostrobin (mean EC50=0.39 µg mL−1) and by DMI (demethylation-inhibiting) fungicide tebuconazole (mean EC50=0.61 µg mL−1), followed by azoxystrobin (mean EC50=2.83 µg mL−1) and flutriafol (mean EC50=2.11 µg mL−1). Multi-site fungicide chlorothalonil and MBC (methyl benzimidazole carbamate) fungicide thiophanate-methyl evinced moderate inhibition with mean EC50=35.31 and 62.83 µg mL−1, respectively. Thirteen isolates were sensitive to SDHI (succinate dehydrogenase inhibitors) fungicide boscalid and fluxapyroxad, (mean EC50=0.49 and 0.19 µg mL−1, respectively), while the rest of isolates were highly resistant.","PeriodicalId":15670,"journal":{"name":"Journal of Environmental Science and Health, Part B","volume":"16 1","pages":"964 - 971"},"PeriodicalIF":0.0,"publicationDate":"2019-08-20","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"87042337","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2019-08-20DOI: 10.1080/03601234.2019.1653121
M. Saad, N. Gouda, S. Abdelgaleil
Abstract This study was undertaken to evaluate the herbicidal activity of twelve natural compounds belonging to monoterpenes, phenylpropenes, and sesquiterpenes against Echinochloa crus-galli under laboratory and glasshouse conditions. Experiments were conducted to determine the impact of different concentrations (0.5, 1, 2, 4 and 8 mM) of these compounds on the seed germination and root and shoot growth of barnyard grass. trans-Cinnamaldehyde, eugenol, and thymol caused the highest impact on barnyard grass reducing its seed germination and shoot growth. p-Cymene (EC50 = 0.22 mM) and trans-cinnamaldehyde (EC50 = 0.34 mM) were the most potent compounds in limiting the root growth of the E. crus-galli. In a post-emergent experiment, thymol, trans-cinnamaldehyde, eugenol, farnesol, and nerolidol significantly reduced the shoot growth, fresh and dry weight of two-leaf stage barnyard grass after 2 days of the foliar treatment with the concentrations of 0.5, 1.0 and 2.0%. These compounds induced severe visible injury symptoms where trans-cinnamaldehyde, eugenol, farnesol and nerolidol showed a complete weed control at 1.0 and 2.0%. These compounds were successfully formulated as emulsifiable concentrates and showed higher herbicidal activities against barnyard grass. Altogether, our data showed that trans-cinnamaldehyde, eugenol, thymol, farnesol, and nerolidol can be developed as novel bioherbicides for managing E. crus-galli.
{"title":"Bioherbicidal activity of terpenes and phenylpropenes against Echinochloa crus-galli","authors":"M. Saad, N. Gouda, S. Abdelgaleil","doi":"10.1080/03601234.2019.1653121","DOIUrl":"https://doi.org/10.1080/03601234.2019.1653121","url":null,"abstract":"Abstract This study was undertaken to evaluate the herbicidal activity of twelve natural compounds belonging to monoterpenes, phenylpropenes, and sesquiterpenes against Echinochloa crus-galli under laboratory and glasshouse conditions. Experiments were conducted to determine the impact of different concentrations (0.5, 1, 2, 4 and 8 mM) of these compounds on the seed germination and root and shoot growth of barnyard grass. trans-Cinnamaldehyde, eugenol, and thymol caused the highest impact on barnyard grass reducing its seed germination and shoot growth. p-Cymene (EC50 = 0.22 mM) and trans-cinnamaldehyde (EC50 = 0.34 mM) were the most potent compounds in limiting the root growth of the E. crus-galli. In a post-emergent experiment, thymol, trans-cinnamaldehyde, eugenol, farnesol, and nerolidol significantly reduced the shoot growth, fresh and dry weight of two-leaf stage barnyard grass after 2 days of the foliar treatment with the concentrations of 0.5, 1.0 and 2.0%. These compounds induced severe visible injury symptoms where trans-cinnamaldehyde, eugenol, farnesol and nerolidol showed a complete weed control at 1.0 and 2.0%. These compounds were successfully formulated as emulsifiable concentrates and showed higher herbicidal activities against barnyard grass. Altogether, our data showed that trans-cinnamaldehyde, eugenol, thymol, farnesol, and nerolidol can be developed as novel bioherbicides for managing E. crus-galli.","PeriodicalId":15670,"journal":{"name":"Journal of Environmental Science and Health, Part B","volume":"18 1","pages":"954 - 963"},"PeriodicalIF":0.0,"publicationDate":"2019-08-20","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"90553290","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2019-08-13DOI: 10.1080/03601234.2019.1652072
A. Al’Abri, S. N. Abdul Halim, N. A. Abu Bakar, S. M. Saharin, Bibi Sherino, H. Rashidi Nodeh, S. Mohamad
Abstract This article demonstrates the first application of a copper-based porous coordination polymer (BTCA-P-Cu-CP) as a carbon paste electrode (CPE) modifier for the detection of malathion. The electrochemical behavior of BTCA-P-Cu-CP/CPE was explored using cyclic voltammetry (CV) while chrono-amperometry methods were applied for the analytical evaluation of the sensor performance. Under optimized conditions, the developed sensor exhibited high reproducibility, stability, and wide dynamic range (0.6–24 nM) with the limits of detection and sensitivity equal to 0.17 nM and 5.7 µAnMcm−1, respectively, based on inhibition signal measurement. Furthermore, the presence of common coexisting interfering species showed a minor change in signals (<4.4%). The developed sensor has been applied in the determination of malathion in spiked vegetable extracts. It exhibited promising results in term of fast and sensitive determination of malathion in real samples at trace level with recoveries of 91.0 to 104.4%. (RSDs < 5%, n = 3). A comparison of the two studied techniques showed that the HPLC technique is unable to detect malathion when the concentration is lower than 1.8 µM while 0.006 µM is detected with appropriate RSDs 0.2–5.2% (n = 3) by amperometric method. Due to the high sensitivity and selectivity, this new electrochemical sensor will be useful for monitoring trace malathion in real samples.
{"title":"Highly sensitive and selective determination of malathion in vegetable extracts by an electrochemical sensor based on Cu-metal organic framework","authors":"A. Al’Abri, S. N. Abdul Halim, N. A. Abu Bakar, S. M. Saharin, Bibi Sherino, H. Rashidi Nodeh, S. Mohamad","doi":"10.1080/03601234.2019.1652072","DOIUrl":"https://doi.org/10.1080/03601234.2019.1652072","url":null,"abstract":"Abstract This article demonstrates the first application of a copper-based porous coordination polymer (BTCA-P-Cu-CP) as a carbon paste electrode (CPE) modifier for the detection of malathion. The electrochemical behavior of BTCA-P-Cu-CP/CPE was explored using cyclic voltammetry (CV) while chrono-amperometry methods were applied for the analytical evaluation of the sensor performance. Under optimized conditions, the developed sensor exhibited high reproducibility, stability, and wide dynamic range (0.6–24 nM) with the limits of detection and sensitivity equal to 0.17 nM and 5.7 µAnMcm−1, respectively, based on inhibition signal measurement. Furthermore, the presence of common coexisting interfering species showed a minor change in signals (<4.4%). The developed sensor has been applied in the determination of malathion in spiked vegetable extracts. It exhibited promising results in term of fast and sensitive determination of malathion in real samples at trace level with recoveries of 91.0 to 104.4%. (RSDs < 5%, n = 3). A comparison of the two studied techniques showed that the HPLC technique is unable to detect malathion when the concentration is lower than 1.8 µM while 0.006 µM is detected with appropriate RSDs 0.2–5.2% (n = 3) by amperometric method. Due to the high sensitivity and selectivity, this new electrochemical sensor will be useful for monitoring trace malathion in real samples.","PeriodicalId":15670,"journal":{"name":"Journal of Environmental Science and Health, Part B","volume":"24 1","pages":"930 - 941"},"PeriodicalIF":0.0,"publicationDate":"2019-08-13","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"91542723","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2019-08-13DOI: 10.1080/03601234.2019.1652073
M. A. Cámara, G. Martínez, S. Cermeño, P. Zafrilla, J. Oliva
Abstract The effect of fenhexamid, mepanipyrim and cyazofamid fungicides on in vitro bioavailability of antioxidant activity and phenolic compounds of Tempranillo and Graciano red wine was studied by simulating the digestive process by dialysis in semipermeable membranes. Determination of antioxidant activity was through reaction with the DPPH • radical and the measurement of phenolic compounds was made with liquid chromatography with diode detector (HPLC-DAD). Fenhexamid, mepanipyrim and cyazofamid reduce the total polyphenol content in both wines. During dialysis there was a large loss of total polyphenols (80–90%) and of antioxidant activity (> 90%). The bioavailability of the phenolic compounds is lower than that for non-treated wines and the highest dialization percentages were found for stilbenes > 50%. While for the remaining phenolic fraction the order is the following hydroxycinnamic derivatives > anthocyanins > flavonols.
{"title":"Influence of fungicide residues and in vitro gastrointestinal digestion on total antioxidant capacity and phenolic fraction of Graciano and Tempranillo red wines","authors":"M. A. Cámara, G. Martínez, S. Cermeño, P. Zafrilla, J. Oliva","doi":"10.1080/03601234.2019.1652073","DOIUrl":"https://doi.org/10.1080/03601234.2019.1652073","url":null,"abstract":"Abstract The effect of fenhexamid, mepanipyrim and cyazofamid fungicides on in vitro bioavailability of antioxidant activity and phenolic compounds of Tempranillo and Graciano red wine was studied by simulating the digestive process by dialysis in semipermeable membranes. Determination of antioxidant activity was through reaction with the DPPH • radical and the measurement of phenolic compounds was made with liquid chromatography with diode detector (HPLC-DAD). Fenhexamid, mepanipyrim and cyazofamid reduce the total polyphenol content in both wines. During dialysis there was a large loss of total polyphenols (80–90%) and of antioxidant activity (> 90%). The bioavailability of the phenolic compounds is lower than that for non-treated wines and the highest dialization percentages were found for stilbenes > 50%. While for the remaining phenolic fraction the order is the following hydroxycinnamic derivatives > anthocyanins > flavonols.","PeriodicalId":15670,"journal":{"name":"Journal of Environmental Science and Health, Part B","volume":"63 1","pages":"942 - 947"},"PeriodicalIF":0.0,"publicationDate":"2019-08-13","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"82184191","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2019-08-12DOI: 10.1080/03601234.2019.1652074
Wei Wang, B. Liu, Xiaoran Duan, Xiaolei Feng, Tuanwei Wang, Pengpeng Wang, Mingcui Ding, Suxiang Liu, Lei Li, Junling Liu, Lixia Tang, X. Niu, Yuhong Zhang, Guoyu Li, W. Yao, Yongli Yang
Abstract Omethoate is an organophosphorus pesticide that poses a major health hazard, especially DNA damage. The purpose of this study was to investigate the factors affecting telomere length in workers exposed to omethoate by analyzing the interaction between cell cycle gene polymorphism and environmental factors. The exposure group consisted of 118 workers exposed to omethoate for 8–10 years, the control group comprised 115 healthy people without occupational toxicant exposure history. The telomere length of genomic DNA from peripheral blood leucocyte was determined with real-time PCR. Polymerase chain reaction and restriction fragment length polymorphism was used to detect the polymorphisms in p53, p21 and MDM2 gene. The telomere length in the (CA + AA) genotypes for p21 rs1801270 polymorphism was longer than that in the CC genotype in control group (P = 0.015). The generalized linear model analysis indicated the interaction of the p21 rs1801270 polymorphic (CA + AA) genotypes and smoking has a significant effect on telomere length (β = −0.258, P = 0.085). The prolongation of telomere length in omethoate-exposed workers was associated with genotypes (CA + AA) of p21 rs1801270, and interactions of (CA + AA) genotypes and smoking factor.
{"title":"Telomere length in workers was effected by omethoate exposure and interaction between smoking and p21 polymorphisms","authors":"Wei Wang, B. Liu, Xiaoran Duan, Xiaolei Feng, Tuanwei Wang, Pengpeng Wang, Mingcui Ding, Suxiang Liu, Lei Li, Junling Liu, Lixia Tang, X. Niu, Yuhong Zhang, Guoyu Li, W. Yao, Yongli Yang","doi":"10.1080/03601234.2019.1652074","DOIUrl":"https://doi.org/10.1080/03601234.2019.1652074","url":null,"abstract":"Abstract Omethoate is an organophosphorus pesticide that poses a major health hazard, especially DNA damage. The purpose of this study was to investigate the factors affecting telomere length in workers exposed to omethoate by analyzing the interaction between cell cycle gene polymorphism and environmental factors. The exposure group consisted of 118 workers exposed to omethoate for 8–10 years, the control group comprised 115 healthy people without occupational toxicant exposure history. The telomere length of genomic DNA from peripheral blood leucocyte was determined with real-time PCR. Polymerase chain reaction and restriction fragment length polymorphism was used to detect the polymorphisms in p53, p21 and MDM2 gene. The telomere length in the (CA + AA) genotypes for p21 rs1801270 polymorphism was longer than that in the CC genotype in control group (P = 0.015). The generalized linear model analysis indicated the interaction of the p21 rs1801270 polymorphic (CA + AA) genotypes and smoking has a significant effect on telomere length (β = −0.258, P = 0.085). The prolongation of telomere length in omethoate-exposed workers was associated with genotypes (CA + AA) of p21 rs1801270, and interactions of (CA + AA) genotypes and smoking factor.","PeriodicalId":15670,"journal":{"name":"Journal of Environmental Science and Health, Part B","volume":"37 1","pages":"948 - 953"},"PeriodicalIF":0.0,"publicationDate":"2019-08-12","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"77300097","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2019-08-09DOI: 10.1080/03601234.2019.1647060
R. A. Mendes, M. Lima, R. A. D. de Deus, A. C. Medeiros, K. Faial, I. Jesus, K. Faial, L. Santos
Abstract In order to assess the risk of exposure of human populations to dichlorodiphenyltrichloroethane (DDT) and mercury, muscles of five fish species were analysed, along with the surface sediment of 14 Iriri River sampling sites. The fish specimens were sacrificed by the spinal section, prior to sex identification, body weight determination and total length. Considering the fish specimens studied, 11% of them showed concentrations of mercury higher than the maximum established by the World Health Organization for safe human consumption. A positive correlation between fish body weight and mercury concentration was observed, besides a positive correlation between the fish size and Hg concentration. Significant differences (P < 0.05) were found between mean concentrations of DDT and metabolites among species of fish studied. In the Plagioscion squamossissimus species, the highest concentration of total DDT (151.4 ng/g) was found, while in Eugerres Brasilianus species, the lowest. However, the DDT levels in fish muscle of studied species are below the maximum set by FAO-Alimentarius CODEX. In the sediments, total DDT ranged from 11.58 ng/g to 48.4 ng/g, which is associated with the historical DDT use in the Amazon. According to sediment quality guidelines, these levels have a moderate toxic effect in almost all of the studied region.
{"title":"Assessment of DDT and mercury levels in fish and sediments in the Iriri River, Brazil: Distribution and ecological risk","authors":"R. A. Mendes, M. Lima, R. A. D. de Deus, A. C. Medeiros, K. Faial, I. Jesus, K. Faial, L. Santos","doi":"10.1080/03601234.2019.1647060","DOIUrl":"https://doi.org/10.1080/03601234.2019.1647060","url":null,"abstract":"Abstract In order to assess the risk of exposure of human populations to dichlorodiphenyltrichloroethane (DDT) and mercury, muscles of five fish species were analysed, along with the surface sediment of 14 Iriri River sampling sites. The fish specimens were sacrificed by the spinal section, prior to sex identification, body weight determination and total length. Considering the fish specimens studied, 11% of them showed concentrations of mercury higher than the maximum established by the World Health Organization for safe human consumption. A positive correlation between fish body weight and mercury concentration was observed, besides a positive correlation between the fish size and Hg concentration. Significant differences (P < 0.05) were found between mean concentrations of DDT and metabolites among species of fish studied. In the Plagioscion squamossissimus species, the highest concentration of total DDT (151.4 ng/g) was found, while in Eugerres Brasilianus species, the lowest. However, the DDT levels in fish muscle of studied species are below the maximum set by FAO-Alimentarius CODEX. In the sediments, total DDT ranged from 11.58 ng/g to 48.4 ng/g, which is associated with the historical DDT use in the Amazon. According to sediment quality guidelines, these levels have a moderate toxic effect in almost all of the studied region.","PeriodicalId":15670,"journal":{"name":"Journal of Environmental Science and Health, Part B","volume":"7 1","pages":"915 - 924"},"PeriodicalIF":0.0,"publicationDate":"2019-08-09","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"77239193","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2019-08-05DOI: 10.1080/03601234.2019.1647753
M. R. Terra, N. F. Tosoni, M. C. Furlaneto, L. Furlaneto-Maia
Abstract Dissemination of vancomycin resistance in enterococci has been associated with horizontal transfer of mobile genetic elements. Aim of the study was to evaluate if milk matrix is a suitable environment to support transferability of vancomycin resistance (vanA) gene from clinical vancomycin-resistant Enterococcus faecium to vancomycin-sensitive Enterococcus faecalis. Enterococci strains were firstly screened for the presence of cpd (inducible sex pheromone determinant) gene, vanA and tetL genes (vancomycin and tetracycline resistance markers, respectively) and the gelE (extracellular metalloendopeptidase) gene to define the mating pairs. Based on these selection markers, we investigated the transferability of eight plasmid-borne vanA harbored by E. faecium (vanA+, cpd-, tetL- and gelE-) into two E. faecalis (vanA-, cpd+, tetL + and gelE+) recipient strains in milk matrix. The strains were mated in a 1:1 ratio in 7% reconstituted milk and incubated at 37 °C. Transconjugants emerged from all 16 matings within 2 h of incubation and were evidenced by dual antibiotic resistance (vancomycin and tetracycline). The vancomycin-resistance of trasconjugants was maintained even after ten subsequent passages on nonselective medium. Transconjugants were positive for vanA, tetL and gelE genes. This study indicates milk matrix as suitable environment to support gene exchange between Enterococcus species.
{"title":"Assessment of vancomycin resistance transfer among enterococci of clinical importance in milk matrix","authors":"M. R. Terra, N. F. Tosoni, M. C. Furlaneto, L. Furlaneto-Maia","doi":"10.1080/03601234.2019.1647753","DOIUrl":"https://doi.org/10.1080/03601234.2019.1647753","url":null,"abstract":"Abstract Dissemination of vancomycin resistance in enterococci has been associated with horizontal transfer of mobile genetic elements. Aim of the study was to evaluate if milk matrix is a suitable environment to support transferability of vancomycin resistance (vanA) gene from clinical vancomycin-resistant Enterococcus faecium to vancomycin-sensitive Enterococcus faecalis. Enterococci strains were firstly screened for the presence of cpd (inducible sex pheromone determinant) gene, vanA and tetL genes (vancomycin and tetracycline resistance markers, respectively) and the gelE (extracellular metalloendopeptidase) gene to define the mating pairs. Based on these selection markers, we investigated the transferability of eight plasmid-borne vanA harbored by E. faecium (vanA+, cpd-, tetL- and gelE-) into two E. faecalis (vanA-, cpd+, tetL + and gelE+) recipient strains in milk matrix. The strains were mated in a 1:1 ratio in 7% reconstituted milk and incubated at 37 °C. Transconjugants emerged from all 16 matings within 2 h of incubation and were evidenced by dual antibiotic resistance (vancomycin and tetracycline). The vancomycin-resistance of trasconjugants was maintained even after ten subsequent passages on nonselective medium. Transconjugants were positive for vanA, tetL and gelE genes. This study indicates milk matrix as suitable environment to support gene exchange between Enterococcus species.","PeriodicalId":15670,"journal":{"name":"Journal of Environmental Science and Health, Part B","volume":"1 1","pages":"925 - 929"},"PeriodicalIF":0.0,"publicationDate":"2019-08-05","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"74860320","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2019-07-25DOI: 10.1080/03601234.2019.1631099
Yu Gao, Meng-Lei Xu, Jinfeng Xiong
Abstract The insecticide thiamethoxam (TMX) is one of the most important neonicotinoid pesticides. The chromatographic methods currently employed to detect TMX require multiple operational steps. This study proposes a simple method that detects TMX via surface-enhanced Raman scattering (SERS) spectroscopy with Ag nanoparticles (NPs) as the SERS active substrate. Density functional theory (DFT) was used to calculate the structures and vibrational modes of the Ag– and Ag3–TMX complexes at the B3LYP/6-311++G(d,p)(C,H,N)/LanL2DZ(Ag) level of theory. The results reveal that the atoms in the thiazole ring all lie in the same plane, while the six-membered ring is perpendicular to the thiazole ring. Data from both Ultraviolet-visible and Raman spectroscopy indicated that TMX bonds to Ag through its nitro group, vertically. A weak intramolecular (N22–O23…H26) hydrogen bonding and Ag–O bands shift N–O symmetrical vibration to down to lower wavenumber. This was supported by the appearance of a strong 866 cm−1 band in the SERS spectrum assigned to the N–O symmetrical vibration coupled with the N–N stretching vibrational mode of different excitation wavelength. Notably, a good linear relationship was observed in the TMX concentration range 1.0 × 10−6–1.0 × 10−4 mol·L−1 (R2 = 0.9667). SERS is an extremely simple and rapid technique that requires little sample for analysis.
{"title":"Raman and SERS spectra of thiamethoxam and the Ag3–thiamethoxam complex: an experimental and theoretical investigation","authors":"Yu Gao, Meng-Lei Xu, Jinfeng Xiong","doi":"10.1080/03601234.2019.1631099","DOIUrl":"https://doi.org/10.1080/03601234.2019.1631099","url":null,"abstract":"Abstract The insecticide thiamethoxam (TMX) is one of the most important neonicotinoid pesticides. The chromatographic methods currently employed to detect TMX require multiple operational steps. This study proposes a simple method that detects TMX via surface-enhanced Raman scattering (SERS) spectroscopy with Ag nanoparticles (NPs) as the SERS active substrate. Density functional theory (DFT) was used to calculate the structures and vibrational modes of the Ag– and Ag3–TMX complexes at the B3LYP/6-311++G(d,p)(C,H,N)/LanL2DZ(Ag) level of theory. The results reveal that the atoms in the thiazole ring all lie in the same plane, while the six-membered ring is perpendicular to the thiazole ring. Data from both Ultraviolet-visible and Raman spectroscopy indicated that TMX bonds to Ag through its nitro group, vertically. A weak intramolecular (N22–O23…H26) hydrogen bonding and Ag–O bands shift N–O symmetrical vibration to down to lower wavenumber. This was supported by the appearance of a strong 866 cm−1 band in the SERS spectrum assigned to the N–O symmetrical vibration coupled with the N–N stretching vibrational mode of different excitation wavelength. Notably, a good linear relationship was observed in the TMX concentration range 1.0 × 10−6–1.0 × 10−4 mol·L−1 (R2 = 0.9667). SERS is an extremely simple and rapid technique that requires little sample for analysis.","PeriodicalId":15670,"journal":{"name":"Journal of Environmental Science and Health, Part B","volume":"4 1","pages":"665 - 675"},"PeriodicalIF":0.0,"publicationDate":"2019-07-25","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"77784541","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2019-07-22DOI: 10.1080/03601234.2019.1641389
M. Badawy, Ayah M E Ismail, Ayah I H Ibrahim
Abstract A selective liquid chromatographic analytical method was studied for determination of two neonicotinoids, acetamiprid and imidacloprid, in tomato fruits under greenhouse conditions in Egypt. The fruits were extracted and cleaned up by QuEChERS method followed by HPLC determination. The method showed a good linearity with a determination coefficient (R2) of higher than 0.99 for the 0.0125–0.15 µg/mL concentration range. The method was validated using a blank tomato spiked at 5, 25 and 50 mg/kg and the recovery percentages were 83.71, 94.52 and 97.49% for acetamiprid and 88.59, 89.63 and 90.18% for imidacloprid, respectively. The rates of dissipation of both pesticides were studied and the preharvest intervals (PHIs) were calculated. Imidacloprid dissipated faster than acetamiprid and half-life periods were 1.30 and 2.07 days, respectively. Acetamiprid and imidacloprid residues were below the already established European maximum residue limits (EU MRLs) (0.5 mg/kg) 3 and 5 days after application, respectively.
{"title":"Quantitative analysis of acetamiprid and imidacloprid residues in tomato fruits under greenhouse conditions","authors":"M. Badawy, Ayah M E Ismail, Ayah I H Ibrahim","doi":"10.1080/03601234.2019.1641389","DOIUrl":"https://doi.org/10.1080/03601234.2019.1641389","url":null,"abstract":"Abstract A selective liquid chromatographic analytical method was studied for determination of two neonicotinoids, acetamiprid and imidacloprid, in tomato fruits under greenhouse conditions in Egypt. The fruits were extracted and cleaned up by QuEChERS method followed by HPLC determination. The method showed a good linearity with a determination coefficient (R2) of higher than 0.99 for the 0.0125–0.15 µg/mL concentration range. The method was validated using a blank tomato spiked at 5, 25 and 50 mg/kg and the recovery percentages were 83.71, 94.52 and 97.49% for acetamiprid and 88.59, 89.63 and 90.18% for imidacloprid, respectively. The rates of dissipation of both pesticides were studied and the preharvest intervals (PHIs) were calculated. Imidacloprid dissipated faster than acetamiprid and half-life periods were 1.30 and 2.07 days, respectively. Acetamiprid and imidacloprid residues were below the already established European maximum residue limits (EU MRLs) (0.5 mg/kg) 3 and 5 days after application, respectively.","PeriodicalId":15670,"journal":{"name":"Journal of Environmental Science and Health, Part B","volume":"13 1","pages":"898 - 905"},"PeriodicalIF":0.0,"publicationDate":"2019-07-22","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"73020732","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
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