The class 1 integron and complex gene cassettes among different species of clinical isolates in northern China were characterized in this study. 383 clinical isolates were obtained from northern China, and class 1 int...The class 1 integron and complex gene cassettes among different species of clinical isolates in northern China were characterized in this study. 383 clinical isolates were obtained from northern China, and class 1 integrons containing gene cassettes widely distributed among gram negative clinical isolates was observed. We find that the class 1 integron showed positive correlation with multidrug resistance phenotype of gram negative bacteria. In addition, we find that isolates belonged to one species harbored different types of gene cassette arrays, while same types of gene cassette arrays were observed in different species of isolates. The diversity of gene cassette arrays among the isolates indicated the complexity of multidrug resistance in clinical isolates in northern China.展开更多
[Objective] This study aimed to investigate the multidrug resistance and prevalence of class I integrons in Salmonel a. [Method] Salmonel a strains were isolated from chicken farms in Shandong Province. Kauffmann-Whi...[Objective] This study aimed to investigate the multidrug resistance and prevalence of class I integrons in Salmonel a. [Method] Salmonel a strains were isolated from chicken farms in Shandong Province. Kauffmann-White classification method was employed to analyze the serotypes of Salmonel a strains. Minimum in-hibition concentration （MIC） of Salmonel a strains against 19 common antimicrobial drugs was analyzed determined with microdilution method. The class I integrons and carried drug resistance gene cassettes were detected by PCR. [Result] A total of 311 Salmonel a strains were isolated and classified into two serotypes, including 133 Salmonel a Indiana strains and 178 Salmonel a Enteritidis strains. Drug sensitivity test showed that the isolated Salmonel a strains were general y resistant to sulfadiazine, sulfamethoxazole, nalidixic acid, ampicil in, tetracycline, doxycycline and trimethoprim, with a multidrug resistance rate of 91.0% （283/311）; 99% strains were sensitive to amikacin and colistin. PCR assay indicated that the detection rate of class I integrons was 65.0% （202/311）; the positive rate of class I integrons in Salmonel a strains with multidrug resistance was 92.6%; among 202 positive strains, six strains carried gene cassette dfr17-aadA5. [Conclusion] According to the above results, class I integrons exist general y in Salmonel a and are closely associated with the multidrug resistance of Salmonel a strains.展开更多
Objective:To investigate the antibiotic resistance genes inserted into class I and class 2integrons in Acinetobacler baumannii[A.baumannii)isolates obtained from nine different cities in Turkey.Methods:A collection of...Objective:To investigate the antibiotic resistance genes inserted into class I and class 2integrons in Acinetobacler baumannii[A.baumannii)isolates obtained from nine different cities in Turkey.Methods:A collection of 281 A.baumannii clinical isolates were collected from nine diferenl state hospitals in Turkey and were confirmed as A.baumannU by conventional biochemical,API testing and bla_(-OXA-51)specific PCR.The isolates were examined by PCR for existence of class I and2 integron gene cassettes.Results:They were characterized by antimicrobial susceptibility testing and the highest resistance rates were determined for piperacillin(90.03%),ciprofloxacin(87.54%),cefepime and trimethoprim/sulfamethoxazole(81.13%).The lowest resistance rates was for cefotaxime(3.55%).class 1 integrons were detected in 6.4%(18/281)of A.baumannii strains and no class 2 integron was detected.The gene casselles of class 1 inlegrons AacCI-AAC(3)l-aadAI,AacCI-aadA1,AAC(3)-I,AAC(3)-I-AAC(3)-I-aadA1,TEM-1.AAC(3)-I-aadA1-AAC(3)-I-AAC(3)-I,AAC(3)-I-AAC(3)-I-AAC(3)-I-aadA1,AAC(3)-I-aadA1,AAC(3)-I-AAC(3)-I,AAC(3)-I-aadA1-AAC(3)-I-aadA1,AAC(3)-I-AAC(3)-I-aadA1-AAC(3)-I-aadA1 were detected in eighteen strains.The aac genes family were most frequently found integrated into the class 1 inlegrons and it was followed by aadA genes and TEM-1 genes.Conclusions:This is an extensive study on the distribulion of class 1 integron among A.baumannii in Turkey.In addition to these,two new alleles were observed.Their percentage rates of similarity to other cassettes are 95%aadA1(TK A18)and 89%,aadA 1(ANKA3).展开更多
目的探讨人参炔三醇(panaxytriol,PXT)抑制氧化低密度脂蛋白(oxidized low density lipoprotein,oxLDL)诱导单核巨噬细胞脂质沉积的作用机制。方法单核细胞THP-1经佛波酯(phorbol-12-myristate-13-acetate,PMA)诱导成巨噬细胞后,采用不...目的探讨人参炔三醇(panaxytriol,PXT)抑制氧化低密度脂蛋白(oxidized low density lipoprotein,oxLDL)诱导单核巨噬细胞脂质沉积的作用机制。方法单核细胞THP-1经佛波酯(phorbol-12-myristate-13-acetate,PMA)诱导成巨噬细胞后,采用不同浓度(0、1、5、10、20μmol/L)PXT处理单核巨噬细胞24小时,通过MTT法检测其对细胞存活率的影响。THP-1单核巨噬细胞经PMA刺激后,利用oxLDL诱导脂质蓄积,PXT处理后利用流式细胞仪,荧光显微镜和油红O染色检测巨噬细胞对oxLDL的摄取。采用Western blot检测细胞内白细胞分化抗原36(cluster of differentiation,CD36)、三磷酸腺苷结合盒转运体A1(ATP-binding cassette transporter A1,ABCA1)、清道夫受体B1(scavenger receptor class B type 1,SRB1)的蛋白表达水平变化。结果MTT实验结果显示,与正常组比较,20μmol/L PXT处理THP-1单核巨噬细胞24小时后显著抑制了细胞活力(P<0.05),且其他浓度对细胞活力均无显著影响。流式细胞检测、细胞荧光成像和油红O染色结果显示,与模型组比较,PXT浓度依赖地降低巨噬细胞内DiI-oxLDL荧光强度与细胞内脂质蓄积(P<0.05)。Western blot结果显示,与模型组比较,PXT浓度依赖地降低了巨噬细胞中CD36蛋白的表达(P<0.05),而对其他蛋白无显著影响。结论PXT通过抑制清道夫受体CD36的表达,抑制巨噬细胞对oxLDL的吞噬及泡沫细胞的形成,具有潜在的抗动脉粥样硬化活性。展开更多
基金supported by Twelfth Five-Year Mega Project of Research on The Prevention and Control of HIV/AIDS,Viral Hepatitis Infectious Diseases 2013ZX10004-217 from the Ministry of Science and Technology,People’s Republic of China,the Project Sponsored by the Young Scholar Scientific Research Foundation of China CDC(No.2013A101)General Program of State Key Laboratory for Infections Disease Prevention and Control(No.2012SKLID205)
文摘The class 1 integron and complex gene cassettes among different species of clinical isolates in northern China were characterized in this study. 383 clinical isolates were obtained from northern China, and class 1 integrons containing gene cassettes widely distributed among gram negative clinical isolates was observed. We find that the class 1 integron showed positive correlation with multidrug resistance phenotype of gram negative bacteria. In addition, we find that isolates belonged to one species harbored different types of gene cassette arrays, while same types of gene cassette arrays were observed in different species of isolates. The diversity of gene cassette arrays among the isolates indicated the complexity of multidrug resistance in clinical isolates in northern China.
基金Supported by National Natural Science Foundation of China(31201949,31172362)~~
文摘[Objective] This study aimed to investigate the multidrug resistance and prevalence of class I integrons in Salmonel a. [Method] Salmonel a strains were isolated from chicken farms in Shandong Province. Kauffmann-White classification method was employed to analyze the serotypes of Salmonel a strains. Minimum in-hibition concentration （MIC） of Salmonel a strains against 19 common antimicrobial drugs was analyzed determined with microdilution method. The class I integrons and carried drug resistance gene cassettes were detected by PCR. [Result] A total of 311 Salmonel a strains were isolated and classified into two serotypes, including 133 Salmonel a Indiana strains and 178 Salmonel a Enteritidis strains. Drug sensitivity test showed that the isolated Salmonel a strains were general y resistant to sulfadiazine, sulfamethoxazole, nalidixic acid, ampicil in, tetracycline, doxycycline and trimethoprim, with a multidrug resistance rate of 91.0% （283/311）; 99% strains were sensitive to amikacin and colistin. PCR assay indicated that the detection rate of class I integrons was 65.0% （202/311）; the positive rate of class I integrons in Salmonel a strains with multidrug resistance was 92.6%; among 202 positive strains, six strains carried gene cassette dfr17-aadA5. [Conclusion] According to the above results, class I integrons exist general y in Salmonel a and are closely associated with the multidrug resistance of Salmonel a strains.
基金Supported by Recep Tayyip Erdogan University(Grant No.BAP2012.102.03.4.and BAP-2013.102.03.4)
文摘Objective:To investigate the antibiotic resistance genes inserted into class I and class 2integrons in Acinetobacler baumannii[A.baumannii)isolates obtained from nine different cities in Turkey.Methods:A collection of 281 A.baumannii clinical isolates were collected from nine diferenl state hospitals in Turkey and were confirmed as A.baumannU by conventional biochemical,API testing and bla_(-OXA-51)specific PCR.The isolates were examined by PCR for existence of class I and2 integron gene cassettes.Results:They were characterized by antimicrobial susceptibility testing and the highest resistance rates were determined for piperacillin(90.03%),ciprofloxacin(87.54%),cefepime and trimethoprim/sulfamethoxazole(81.13%).The lowest resistance rates was for cefotaxime(3.55%).class 1 integrons were detected in 6.4%(18/281)of A.baumannii strains and no class 2 integron was detected.The gene casselles of class 1 inlegrons AacCI-AAC(3)l-aadAI,AacCI-aadA1,AAC(3)-I,AAC(3)-I-AAC(3)-I-aadA1,TEM-1.AAC(3)-I-aadA1-AAC(3)-I-AAC(3)-I,AAC(3)-I-AAC(3)-I-AAC(3)-I-aadA1,AAC(3)-I-aadA1,AAC(3)-I-AAC(3)-I,AAC(3)-I-aadA1-AAC(3)-I-aadA1,AAC(3)-I-AAC(3)-I-aadA1-AAC(3)-I-aadA1 were detected in eighteen strains.The aac genes family were most frequently found integrated into the class 1 inlegrons and it was followed by aadA genes and TEM-1 genes.Conclusions:This is an extensive study on the distribulion of class 1 integron among A.baumannii in Turkey.In addition to these,two new alleles were observed.Their percentage rates of similarity to other cassettes are 95%aadA1(TK A18)and 89%,aadA 1(ANKA3).
文摘目的探讨人参炔三醇(panaxytriol,PXT)抑制氧化低密度脂蛋白(oxidized low density lipoprotein,oxLDL)诱导单核巨噬细胞脂质沉积的作用机制。方法单核细胞THP-1经佛波酯(phorbol-12-myristate-13-acetate,PMA)诱导成巨噬细胞后,采用不同浓度(0、1、5、10、20μmol/L)PXT处理单核巨噬细胞24小时,通过MTT法检测其对细胞存活率的影响。THP-1单核巨噬细胞经PMA刺激后,利用oxLDL诱导脂质蓄积,PXT处理后利用流式细胞仪,荧光显微镜和油红O染色检测巨噬细胞对oxLDL的摄取。采用Western blot检测细胞内白细胞分化抗原36(cluster of differentiation,CD36)、三磷酸腺苷结合盒转运体A1(ATP-binding cassette transporter A1,ABCA1)、清道夫受体B1(scavenger receptor class B type 1,SRB1)的蛋白表达水平变化。结果MTT实验结果显示,与正常组比较,20μmol/L PXT处理THP-1单核巨噬细胞24小时后显著抑制了细胞活力(P<0.05),且其他浓度对细胞活力均无显著影响。流式细胞检测、细胞荧光成像和油红O染色结果显示,与模型组比较,PXT浓度依赖地降低巨噬细胞内DiI-oxLDL荧光强度与细胞内脂质蓄积(P<0.05)。Western blot结果显示,与模型组比较,PXT浓度依赖地降低了巨噬细胞中CD36蛋白的表达(P<0.05),而对其他蛋白无显著影响。结论PXT通过抑制清道夫受体CD36的表达,抑制巨噬细胞对oxLDL的吞噬及泡沫细胞的形成,具有潜在的抗动脉粥样硬化活性。
文摘目的:观察氧化型低密度脂蛋白(oxidized low-density lipoprotein,ox-LDL)干预是否刺激分化成熟的3T3-L1脂肪细胞胆固醇流出,并探讨其机制。方法:3T3-L1细胞促分化成熟后,给予不同浓度的ox-LDL(0～50μg/mL)干预8或24h;在以25μg/mL ox-LDL预处理脂肪细胞24h后,再以10μmol/L22(R)-羟基胆固醇干预24h,收集细胞,采用逆转录聚合酶链反应(reverse transcription polymer-ase chain reaction,RT-PCR)测定脂肪细胞三磷酸腺苷结合盒转运体A1(ATP binding cassette transporterA1,ABCA1),B族I型清道夫受体(scavenger receptor class B type I,SR-BI)和肝X受体α(liver X receptorα,LXRα)mRNA表达,采用液体闪烁计数器检测载脂蛋白A-I(apolipoprotein A-I,apoA-I)介导的细胞内胆固醇流出。结果:低浓度ox-LDL(12.5～25μg/mL)干预24h可增加脂肪细胞ABCA1,LXRα和SR-BImRNA的表达,并促进apoA-I介导的胆固醇流出,而高浓度(50μg/mL)则无此作用。将脂肪细胞用25μg/mL ox-LDL预处理24h,再用10μmol/L22(R)-羟基胆固醇干预细胞,ABCA1和LXRαmRNA表达均有显著增加(P<0.01),同时apoA-I介导的胆固醇流出增加,而SR-BImRNA表达无明显改变。结论:低浓度ox-LDL不仅可促进脂肪细胞LXRα-ABCA1-apoA-I通路,还可上调SR-BI表达,加速细胞内胆固醇流出。Ox-LDL这种新的作用不仅有利于维持脂肪细胞内胆固醇的动态平衡,还可能具有抗动脉粥样硬化作用。
