Background: Nowadays, emergence of Carbapenemase-Producing Enterobacterales (CPE) throughout the world has become a public health problem, especially in countries with limited resources. In recent years, CPE of type O...Background: Nowadays, emergence of Carbapenemase-Producing Enterobacterales (CPE) throughout the world has become a public health problem, especially in countries with limited resources. In recent years, CPE of type OXA-48 (Ambler class D) have been identified in Dakar. The aim of this study was to evaluate the phenotypic detection of OXA-48 CPE using a temocillin disc (30 μg). Methodology: A retrospective study was carried out at Medical Biology Laboratory of Pasteur Institute in Dakar on Ertapenem-Resistant Enterobacterales (ERE) strains isolated from 2015 to 2017. These strains were then tested with a 30 μg temocillin disc. Any strain resistant to temocillin (inhibition diameter Results: Forty-one ERE isolated during the study period were tested, of which 34 (82.9%) were OXA-48 based on phenotypic detection using temocillin disc and confirmed by PCR (100%). OXA-48 CPE strains detected were composed of Klebsiella pneumoniae (n = 14;41.2%), Enterobacter cloacae (n = 8;23.5%), Escherichia coli (n = 7, 20.5%), Citrobacter freundii (n = 3;8.8%), Cronobacter sakazakii (n = 1;3%) and Morganella morganii (n = 1;3%). Conclusion: Temocillin resistance has a good positive predictive value for detecting OXA-48 CPE by phenotypic method, confirmed by PCR. Temocillin is therefore a good marker for detection of OXA-48 CPE except Hafnia alvei.展开更多
Objective The aim of the current study was to establish an oxaliplatin-resistant hepatoma cell line(HepG2/OXA) and investigate the potential mechanisms of its drug resistance.Methods The hepatoma cell subline, HepG2/O...Objective The aim of the current study was to establish an oxaliplatin-resistant hepatoma cell line(HepG2/OXA) and investigate the potential mechanisms of its drug resistance.Methods The hepatoma cell subline, HepG2/OXA, resistant to oxaliplatin(OXA), was established from a parent cell line HepG2, by stepwise exposure to gradually increasing concentrations of OXA over a half-year period. Chemosenstivity of the cytotoxic drugs, OXA, cisplatin(CDDP), adriamycin(ADM), and 5-fuorouracil(5-FU), was determined in HepG2 and HepG2/OXA cells, by the Cell counting kit-8(CCK8) assay. Cell cycle distribution of HepG2 and HepG2/OXA cells was analyzed by Flow cytometry(FCM). The expression levels of several drug resistance-related proteins, such as P-glycoprotein(P-gp), multidrug resistant protein 1(MRP1), and excision repair-cross complementing 1(ERCC1) protein in the two cell lines were tested by the western blot assay.Results The IC50 of OXA in HepG2/OXA and HepG2 were 136.84 μmol/L and 23.86 μmol/L, respectively. The resistance index(RI) was 5.34. HepG2 was also demonstrated to be cross-resistant to other antitumor agents, such as 5-FU, ADM, and CDDP. The percentage of HepG2/OXA cells in the S phase was significantly decreased compared to HepG2 cells(25.58% ± 2.36% vs 14.37% ± 2.54%, P < 0.05), while the percentage of cells in the G0/G1 and G2/M phases showed no statistical difference(respectively 55.29% ± 4.98% vs 56.73% ± 4.56%, P > 0.05, and 24.63% ± 4.81% vs 28.26% ± 3.82%, P > 0.05). The ERCC1 was found to be over expressed in HepG2/OXA cells, while there was no difference in the expressions of P-gp and MRP1 between the multiple drug resistance(MDR) phenotype cell line and its parental cell line.Conclusion HepG2/OXA showed an MDR ability; the over expression of ERCC1 might be associated with the platinum resistance of the cells, but P-gp and MRP1 are not.展开更多
目的研究复方五味子素B对耐奥沙利铂人结肠癌细胞(TH C-8307/O X A)多药耐药性的逆转作用及其机制。方法采用噻唑蓝(M TT)比色法检测奥沙利铂(O X A)和复方五味子素B(γSC)的细胞毒性;碱性磷酸酶免疫组织化学法和W estern blot检测γSC...目的研究复方五味子素B对耐奥沙利铂人结肠癌细胞(TH C-8307/O X A)多药耐药性的逆转作用及其机制。方法采用噻唑蓝(M TT)比色法检测奥沙利铂(O X A)和复方五味子素B(γSC)的细胞毒性;碱性磷酸酶免疫组织化学法和W estern blot检测γSC对TH C-8307/O X A细胞G ST-п蛋白水平的影响。结果γSC(6.0、12.5和25.0μg/m L)对人结肠癌细胞(TH C-8307)和耐奥沙利铂人结肠癌细胞(TH C-8307/O XA)无显著毒性作用(P>0.05),O X A对TH C-8307的IC 50为0.06μg/m L,而对TH C-8307/O X A的IC 50为2.32μg/m L,TH C-8307/O X A是TH C-8307对O X A耐药的39倍,γSC(6.0、12.5和25.0μg/m L)能使O X A对TH C-8307/O X A细胞的IC 50从2.32μg/m L依次下降至0.370、0.128和0.057μg/m L,逆转倍数分别为6.2、18.1和40.7倍。碱性磷酸酶免疫组织化学法和W estern blot检测γSC(12.5μg/m L)处理48 h后,TH C-8307/O X A细胞G ST-п蛋白表达明显降低。结论γSC具有逆转耐奥沙利铂人结肠癌细胞的M D R作用,其作用机制与下调G ST-п表达有关。展开更多
文摘Background: Nowadays, emergence of Carbapenemase-Producing Enterobacterales (CPE) throughout the world has become a public health problem, especially in countries with limited resources. In recent years, CPE of type OXA-48 (Ambler class D) have been identified in Dakar. The aim of this study was to evaluate the phenotypic detection of OXA-48 CPE using a temocillin disc (30 μg). Methodology: A retrospective study was carried out at Medical Biology Laboratory of Pasteur Institute in Dakar on Ertapenem-Resistant Enterobacterales (ERE) strains isolated from 2015 to 2017. These strains were then tested with a 30 μg temocillin disc. Any strain resistant to temocillin (inhibition diameter Results: Forty-one ERE isolated during the study period were tested, of which 34 (82.9%) were OXA-48 based on phenotypic detection using temocillin disc and confirmed by PCR (100%). OXA-48 CPE strains detected were composed of Klebsiella pneumoniae (n = 14;41.2%), Enterobacter cloacae (n = 8;23.5%), Escherichia coli (n = 7, 20.5%), Citrobacter freundii (n = 3;8.8%), Cronobacter sakazakii (n = 1;3%) and Morganella morganii (n = 1;3%). Conclusion: Temocillin resistance has a good positive predictive value for detecting OXA-48 CPE by phenotypic method, confirmed by PCR. Temocillin is therefore a good marker for detection of OXA-48 CPE except Hafnia alvei.
基金Supported by grants from the National Natural Sciences Foundation of China(No.81001067)Ministry of Science and Technology International Cooperation Project(No.S2010GR0991)Astrazeneca Special Research Foundation for Targeted Therapy of Wu Jieping Medical Foundation(No.320.6700.09068)
文摘Objective The aim of the current study was to establish an oxaliplatin-resistant hepatoma cell line(HepG2/OXA) and investigate the potential mechanisms of its drug resistance.Methods The hepatoma cell subline, HepG2/OXA, resistant to oxaliplatin(OXA), was established from a parent cell line HepG2, by stepwise exposure to gradually increasing concentrations of OXA over a half-year period. Chemosenstivity of the cytotoxic drugs, OXA, cisplatin(CDDP), adriamycin(ADM), and 5-fuorouracil(5-FU), was determined in HepG2 and HepG2/OXA cells, by the Cell counting kit-8(CCK8) assay. Cell cycle distribution of HepG2 and HepG2/OXA cells was analyzed by Flow cytometry(FCM). The expression levels of several drug resistance-related proteins, such as P-glycoprotein(P-gp), multidrug resistant protein 1(MRP1), and excision repair-cross complementing 1(ERCC1) protein in the two cell lines were tested by the western blot assay.Results The IC50 of OXA in HepG2/OXA and HepG2 were 136.84 μmol/L and 23.86 μmol/L, respectively. The resistance index(RI) was 5.34. HepG2 was also demonstrated to be cross-resistant to other antitumor agents, such as 5-FU, ADM, and CDDP. The percentage of HepG2/OXA cells in the S phase was significantly decreased compared to HepG2 cells(25.58% ± 2.36% vs 14.37% ± 2.54%, P < 0.05), while the percentage of cells in the G0/G1 and G2/M phases showed no statistical difference(respectively 55.29% ± 4.98% vs 56.73% ± 4.56%, P > 0.05, and 24.63% ± 4.81% vs 28.26% ± 3.82%, P > 0.05). The ERCC1 was found to be over expressed in HepG2/OXA cells, while there was no difference in the expressions of P-gp and MRP1 between the multiple drug resistance(MDR) phenotype cell line and its parental cell line.Conclusion HepG2/OXA showed an MDR ability; the over expression of ERCC1 might be associated with the platinum resistance of the cells, but P-gp and MRP1 are not.
文摘目的研究复方五味子素B对耐奥沙利铂人结肠癌细胞(TH C-8307/O X A)多药耐药性的逆转作用及其机制。方法采用噻唑蓝(M TT)比色法检测奥沙利铂(O X A)和复方五味子素B(γSC)的细胞毒性;碱性磷酸酶免疫组织化学法和W estern blot检测γSC对TH C-8307/O X A细胞G ST-п蛋白水平的影响。结果γSC(6.0、12.5和25.0μg/m L)对人结肠癌细胞(TH C-8307)和耐奥沙利铂人结肠癌细胞(TH C-8307/O XA)无显著毒性作用(P>0.05),O X A对TH C-8307的IC 50为0.06μg/m L,而对TH C-8307/O X A的IC 50为2.32μg/m L,TH C-8307/O X A是TH C-8307对O X A耐药的39倍,γSC(6.0、12.5和25.0μg/m L)能使O X A对TH C-8307/O X A细胞的IC 50从2.32μg/m L依次下降至0.370、0.128和0.057μg/m L,逆转倍数分别为6.2、18.1和40.7倍。碱性磷酸酶免疫组织化学法和W estern blot检测γSC(12.5μg/m L)处理48 h后,TH C-8307/O X A细胞G ST-п蛋白表达明显降低。结论γSC具有逆转耐奥沙利铂人结肠癌细胞的M D R作用,其作用机制与下调G ST-п表达有关。
