Rivers can act as reservoirs of highly resistant strains and facilitate the dissemination of resistance, virulence and integron 1 genes. A cross-sectional study was carried out where 318 water samples were collected (...Rivers can act as reservoirs of highly resistant strains and facilitate the dissemination of resistance, virulence and integron 1 genes. A cross-sectional study was carried out where 318 water samples were collected (53 from each site) and from the samples, 318 E. coli isolates were analysed for resistance genes, virulence genes and integron 1 using Polymerase Chain Reaction. 22% of the isolates had blaTEM, 33% had blaCTX-M and 28% had blaCMY. Prevalence of typical Enteropathogenic E. coli strains (carrying both eae and bfp genes) was 5% while the prevalence of atypical Enteropathogenic E. coli (carying only eae) was 1.8%. The prevalence of Enteroaggregative E. coli carrying the aggr genes was 11%. The prevalence of Enterotoxigenic E. coli encoding only lt toxin was 16 (5%) and while those carrying only st toxin was 6.9%. The prevalence of Enteroinvasive E. coli strains encoding as IpaH was 5% while that of strains, adherent invasive E. coli, carrying adherent invasive gene inv was 8.7%. 36% isolates were positive for class 1 integrons which were mostly isolated near the sewage effluent from waste treatment plant. Anthropogenic activities and close proximity to sewage treatment plant were found to play a key role in pollution of water body and accumulation of resistance and virulence genes. These results suggest that waste treatment plant may act as reservoir of resistance, virulence and integron 1 genes and is a potential risk to human and animal health in the region.展开更多
Antimicrobial use in agriculture, livestock and human health has increased over the years leading to the increase in antimicrobial resistance that can also find its way to the aquatic environment. Rivers can act as re...Antimicrobial use in agriculture, livestock and human health has increased over the years leading to the increase in antimicrobial resistance that can also find its way to the aquatic environment. Rivers can act as reservoirs of highly resistant strains and facilitate the dissemination of multidrug resistant (MDR) strains to animals and humans using water. A total of 318 water samples were collected from six different sampling points along Athi River and E. coli isolates were subjected to Kirby-Bauer diffusion method for antimicrobial susceptibility testing. The total mean coliform count of the sampled sites was 2.7 × 104 (cfu/mL). E. coli isolates were most resistant to ampicillin (63.8%) and most susceptible to gentamicin (99.4%). MDR strains (resistance to ≥3 classes of antibiotics) accounted for 65.4% of all the isolates. The site recorded to have human industrial and agricultural zone activities had strains that were significantly more resistant to ampicillin, cefoxitin, amoxicillin/clavulanic acid (P ≤ 0.05) than isolates from the section of the river traversing virgin land and land with minimum human activities. This study indicates that E. coli strains isolated from Athi River were highly MDR and most resistant to some antimicrobial classes (ampicillin and cefoxitin) which constitute a potential risk to human and animal health.展开更多
Information about effectiveness of a wastewater treatment plant is vital in ensuring the quality of water discharged into water bodies and the environment in general meet set standards.In this study,the performance of...Information about effectiveness of a wastewater treatment plant is vital in ensuring the quality of water discharged into water bodies and the environment in general meet set standards.In this study,the performance of a wastewater treatment plant located at the Export Processing Zone(EPZ)along River Athi in Machakos County,Kenya was assessed because the final effluent from the treatment plant is released into the river where water is used downstream.Effectiveness of the plant was assessed through the reduction percentage of pollutants between influent and effluent during the dry and wet seasons.Samples of water were collected from the following points i.e.inlet,outflow pool,outlet and along the river.The samples were analyzed for heavy metals,Total Dissolved Solids(TDS),Total Suspended Solids(TSS),Chemical Oxygen Demand(COD),Biological Oxygen Demand(BOD),organic nitrogen,phosphate,color,temperature,pH,and total coliforms.The resulting data was compared with the established standards.Standard methodologies of laboratory analysis were employed as per Kenyan regulations of 2006 on waste water treatment and discharge.From the results,the waste water treatment plant was not effective in reducing nitrates,phosphates,TDS,TSS,color,and heavy metals i.e.mercury,lead,selenium,copper and cadmium.The inefficiency was more pronounced in rain season.Nitrates(-2.04%),phosphates(-66%),mercury(-48%),lead(-48%),selenium(-2.29%)and copper(-9.75%)were high in the effluent after treatment process during the rains than in the influent.However,the treatment plant was effective in reducing Chemical Oxygen Demand(COD)and Biological Oxygen Demand(BOD).Some parameters like pH,conductivity,temperature,color and TSS were within allowable values described by Kenyan and International standards for effluent discharge into public waters.The study recommends expansion or re-designing of the treatment plant and better monitoring of the sources or types of wastewaters received at the plant for efficient and proper treatment process.Further research required on the seasonal fluctuation of pollutants along River Athi to reduce pollution of the waters.This should be coupled with studying the role of river gradient in self-cleansing of the pollutants.展开更多
以巢湖典型支流丰乐河流域为例,利用分布式水文模型ATHYS对流域降雨—径流过程进行模拟,以期为丰乐河流域水土保持、防洪、水资源利用和非点源污染防治等提供科学依据。ATHYS模型将流域分为大小相同的空间小单元,以库模型进行产流计算,...以巢湖典型支流丰乐河流域为例,利用分布式水文模型ATHYS对流域降雨—径流过程进行模拟,以期为丰乐河流域水土保持、防洪、水资源利用和非点源污染防治等提供科学依据。ATHYS模型将流域分为大小相同的空间小单元,以库模型进行产流计算,以滞后演算法(lag and route)方法进行汇流计算,并以Nash and Sutcliffe指数作为检验模拟结果的标准,模拟流域出口断面日径流量,初步分析流域径流实测值与模拟值的年际变化。模型模拟结果表明,在率定期和验证期模拟与实测径流量的总Nash and Sutcliffe值(Nash值)都可以达到0.80以上,相关系数均可达0.89以上。除了部分峰值和基流,模型能较好地模拟丰乐河的径流过程。模型模拟径流总量的相对误差在率定期为23.1%,验证期为34.6%。流域降雨量、径流量的年内、年际变化均比较明显,径流实测值和模拟值的年际变化也都比较大。综合来看,模型比较适用于所研究流域的日径流模拟。展开更多
目的:通过观察丹蛭降糖胶囊对2型糖尿病患者大血管Wnt/β-链蛋白(Wnt/β-catenin)、糖原合成酶激酶-3(GSK-3β)通路表达,以及对颈动脉内膜中层厚度(IMT)和斑块面积的影响,评价丹蛭降糖胶囊对2型糖尿病患者大血管病变的保护作用。方法:将...目的:通过观察丹蛭降糖胶囊对2型糖尿病患者大血管Wnt/β-链蛋白(Wnt/β-catenin)、糖原合成酶激酶-3(GSK-3β)通路表达,以及对颈动脉内膜中层厚度(IMT)和斑块面积的影响,评价丹蛭降糖胶囊对2型糖尿病患者大血管病变的保护作用。方法:将102例2型糖尿病患者随机分为对照组和治疗组各51人。所有患者给予基础药物(常规口服降糖药物)治疗,治疗组采用基础药物+丹蛭降糖胶囊,疗程均为16周。结果:16周后治疗组总有效率84.31%,优于对照组的64.71%,差异有统计学意义(P<0.05);两组治疗前后比较中医证候积分、FPG、2 h PG、Hb A1c、TC、TG、LDL、HDL、颈动脉IMT及斑块面积水平都有所改善(P<0.05或P<0.01);组间比较,治疗组中医证候积分、2 h PG、Hb A1c、TG及LDL水平下降,具有统计学差异(P<0.05或P<0.01);治疗组IMT改善情况优于对照组(P<0.05),但斑块面积改善情况无统计学意义(P>0.05)。治疗后,治疗组血清β-catenin水平较对照组显著降低(P<0.01),血清GSK-3β水平比对照组降低,差异有统计学意义(P<0.05)。结论:丹蛭降糖胶囊可以显著缓解2型糖尿病患者临床症状,并在一定程度上改善或逆转颈动脉硬化进程。展开更多
Alternaria tenuissima is a fungus widely present in the environment and could cause diseases in plants and humans. In this study, through a yeast genetic approach, cDNA sequences were isolated and characterized for th...Alternaria tenuissima is a fungus widely present in the environment and could cause diseases in plants and humans. In this study, through a yeast genetic approach, cDNA sequences were isolated and characterized for the AtHIS3 and AtLEU2 genes. AtHIS3 cDNA encodes a protein of 238 amino acids, while AtLEU2 cDNA encodes a protein of 363 amino acids. Based on the phylogenetic analysis of amino acid sequences of AtHis3p and AtLeu2p, A. tenuissima is closely related to the plant pathogenic fungus Phaeosphaeria nodorum. This study provides two genetic markers for studies of functions of genes regulating development, morphology, and virulence of A. tenuissima.展开更多
文摘Rivers can act as reservoirs of highly resistant strains and facilitate the dissemination of resistance, virulence and integron 1 genes. A cross-sectional study was carried out where 318 water samples were collected (53 from each site) and from the samples, 318 E. coli isolates were analysed for resistance genes, virulence genes and integron 1 using Polymerase Chain Reaction. 22% of the isolates had blaTEM, 33% had blaCTX-M and 28% had blaCMY. Prevalence of typical Enteropathogenic E. coli strains (carrying both eae and bfp genes) was 5% while the prevalence of atypical Enteropathogenic E. coli (carying only eae) was 1.8%. The prevalence of Enteroaggregative E. coli carrying the aggr genes was 11%. The prevalence of Enterotoxigenic E. coli encoding only lt toxin was 16 (5%) and while those carrying only st toxin was 6.9%. The prevalence of Enteroinvasive E. coli strains encoding as IpaH was 5% while that of strains, adherent invasive E. coli, carrying adherent invasive gene inv was 8.7%. 36% isolates were positive for class 1 integrons which were mostly isolated near the sewage effluent from waste treatment plant. Anthropogenic activities and close proximity to sewage treatment plant were found to play a key role in pollution of water body and accumulation of resistance and virulence genes. These results suggest that waste treatment plant may act as reservoir of resistance, virulence and integron 1 genes and is a potential risk to human and animal health in the region.
文摘Antimicrobial use in agriculture, livestock and human health has increased over the years leading to the increase in antimicrobial resistance that can also find its way to the aquatic environment. Rivers can act as reservoirs of highly resistant strains and facilitate the dissemination of multidrug resistant (MDR) strains to animals and humans using water. A total of 318 water samples were collected from six different sampling points along Athi River and E. coli isolates were subjected to Kirby-Bauer diffusion method for antimicrobial susceptibility testing. The total mean coliform count of the sampled sites was 2.7 × 104 (cfu/mL). E. coli isolates were most resistant to ampicillin (63.8%) and most susceptible to gentamicin (99.4%). MDR strains (resistance to ≥3 classes of antibiotics) accounted for 65.4% of all the isolates. The site recorded to have human industrial and agricultural zone activities had strains that were significantly more resistant to ampicillin, cefoxitin, amoxicillin/clavulanic acid (P ≤ 0.05) than isolates from the section of the river traversing virgin land and land with minimum human activities. This study indicates that E. coli strains isolated from Athi River were highly MDR and most resistant to some antimicrobial classes (ampicillin and cefoxitin) which constitute a potential risk to human and animal health.
文摘Information about effectiveness of a wastewater treatment plant is vital in ensuring the quality of water discharged into water bodies and the environment in general meet set standards.In this study,the performance of a wastewater treatment plant located at the Export Processing Zone(EPZ)along River Athi in Machakos County,Kenya was assessed because the final effluent from the treatment plant is released into the river where water is used downstream.Effectiveness of the plant was assessed through the reduction percentage of pollutants between influent and effluent during the dry and wet seasons.Samples of water were collected from the following points i.e.inlet,outflow pool,outlet and along the river.The samples were analyzed for heavy metals,Total Dissolved Solids(TDS),Total Suspended Solids(TSS),Chemical Oxygen Demand(COD),Biological Oxygen Demand(BOD),organic nitrogen,phosphate,color,temperature,pH,and total coliforms.The resulting data was compared with the established standards.Standard methodologies of laboratory analysis were employed as per Kenyan regulations of 2006 on waste water treatment and discharge.From the results,the waste water treatment plant was not effective in reducing nitrates,phosphates,TDS,TSS,color,and heavy metals i.e.mercury,lead,selenium,copper and cadmium.The inefficiency was more pronounced in rain season.Nitrates(-2.04%),phosphates(-66%),mercury(-48%),lead(-48%),selenium(-2.29%)and copper(-9.75%)were high in the effluent after treatment process during the rains than in the influent.However,the treatment plant was effective in reducing Chemical Oxygen Demand(COD)and Biological Oxygen Demand(BOD).Some parameters like pH,conductivity,temperature,color and TSS were within allowable values described by Kenyan and International standards for effluent discharge into public waters.The study recommends expansion or re-designing of the treatment plant and better monitoring of the sources or types of wastewaters received at the plant for efficient and proper treatment process.Further research required on the seasonal fluctuation of pollutants along River Athi to reduce pollution of the waters.This should be coupled with studying the role of river gradient in self-cleansing of the pollutants.
文摘以巢湖典型支流丰乐河流域为例,利用分布式水文模型ATHYS对流域降雨—径流过程进行模拟,以期为丰乐河流域水土保持、防洪、水资源利用和非点源污染防治等提供科学依据。ATHYS模型将流域分为大小相同的空间小单元,以库模型进行产流计算,以滞后演算法(lag and route)方法进行汇流计算,并以Nash and Sutcliffe指数作为检验模拟结果的标准,模拟流域出口断面日径流量,初步分析流域径流实测值与模拟值的年际变化。模型模拟结果表明,在率定期和验证期模拟与实测径流量的总Nash and Sutcliffe值(Nash值)都可以达到0.80以上,相关系数均可达0.89以上。除了部分峰值和基流,模型能较好地模拟丰乐河的径流过程。模型模拟径流总量的相对误差在率定期为23.1%,验证期为34.6%。流域降雨量、径流量的年内、年际变化均比较明显,径流实测值和模拟值的年际变化也都比较大。综合来看,模型比较适用于所研究流域的日径流模拟。
文摘目的:通过观察丹蛭降糖胶囊对2型糖尿病患者大血管Wnt/β-链蛋白(Wnt/β-catenin)、糖原合成酶激酶-3(GSK-3β)通路表达,以及对颈动脉内膜中层厚度(IMT)和斑块面积的影响,评价丹蛭降糖胶囊对2型糖尿病患者大血管病变的保护作用。方法:将102例2型糖尿病患者随机分为对照组和治疗组各51人。所有患者给予基础药物(常规口服降糖药物)治疗,治疗组采用基础药物+丹蛭降糖胶囊,疗程均为16周。结果:16周后治疗组总有效率84.31%,优于对照组的64.71%,差异有统计学意义(P<0.05);两组治疗前后比较中医证候积分、FPG、2 h PG、Hb A1c、TC、TG、LDL、HDL、颈动脉IMT及斑块面积水平都有所改善(P<0.05或P<0.01);组间比较,治疗组中医证候积分、2 h PG、Hb A1c、TG及LDL水平下降,具有统计学差异(P<0.05或P<0.01);治疗组IMT改善情况优于对照组(P<0.05),但斑块面积改善情况无统计学意义(P>0.05)。治疗后,治疗组血清β-catenin水平较对照组显著降低(P<0.01),血清GSK-3β水平比对照组降低,差异有统计学意义(P<0.05)。结论:丹蛭降糖胶囊可以显著缓解2型糖尿病患者临床症状,并在一定程度上改善或逆转颈动脉硬化进程。
文摘Alternaria tenuissima is a fungus widely present in the environment and could cause diseases in plants and humans. In this study, through a yeast genetic approach, cDNA sequences were isolated and characterized for the AtHIS3 and AtLEU2 genes. AtHIS3 cDNA encodes a protein of 238 amino acids, while AtLEU2 cDNA encodes a protein of 363 amino acids. Based on the phylogenetic analysis of amino acid sequences of AtHis3p and AtLeu2p, A. tenuissima is closely related to the plant pathogenic fungus Phaeosphaeria nodorum. This study provides two genetic markers for studies of functions of genes regulating development, morphology, and virulence of A. tenuissima.
