Colistin has been regarded as the last line antibiotic for treatment of infections caused by multidrug resistant gram-negative bacteria. Therefore, the increasing emergence of colistin resistance among gram-negative b...Colistin has been regarded as the last line antibiotic for treatment of infections caused by multidrug resistant gram-negative bacteria. Therefore, the increasing emergence of colistin resistance among gram-negative bacteria represents a serious problem. The objective of this study was to characterize the effectiveness of the chemically synthesized thanatin in linear form against colistin-resistant E. coli isolated from a pig farm in China. Agar diffusion assay and broth microdilution test were employed to analyze the susceptibility of colistin-sensitive E. coli (ATCC25922) and colistin-resistant E. coli (SHP45) to linear thanatin (L-thanatin). Combinatory effect of linear thanatin and colistin against E. coli was also determined by fractional inhibition concentration index (FICI) analysis. The results showed that L-thanatin at a concentration of 1 mg/ml produced larger inhibition zone on agar against ATCC25922 than SHP45. In the quantitative microdilution test, L-thanatin had the same MIC of 3.2 μg/ml for ATCC25922 and SHP45. Based on the FICI analysis, additive effect was obtained with 1.56 μg/ml of L-thanatin and 0.125 μg/ml of colistin for ATCC25922;but with 1.56 μg/ml of L-thanatin and 0.25 μg/ml of colistin or with 2 μg/ml of colistin and 0.39 μg/ml of L-thanatin for SHP45. These data proved that L-thanatin is an effective antimicrobial peptide against colistin-resistant E. coli.展开更多
为了解河南省焦作市、许昌市规模化养殖厂耐黏菌素大肠杆菌的流行情况,对分离到的32株耐黏菌素大肠杆菌使用微量肉汤稀释法检测其药物敏感性,并采用脉冲场凝胶电泳(Pulsed field gel electrophoresis,PFGE)对分离株进行分型研究。结果显...为了解河南省焦作市、许昌市规模化养殖厂耐黏菌素大肠杆菌的流行情况,对分离到的32株耐黏菌素大肠杆菌使用微量肉汤稀释法检测其药物敏感性,并采用脉冲场凝胶电泳(Pulsed field gel electrophoresis,PFGE)对分离株进行分型研究。结果显示,32株耐黏菌素大肠杆菌对四环素、多西环素、磺胺异噁唑、复方新诺明的耐药率均高达90%以上,32株猪源大肠杆菌可分为30种带型。结果表明,两地市养殖场猪源大肠杆菌耐药性普遍存在,且以多重耐药为主,PFGE分型结果显示,32株耐黏菌素大肠杆菌整体上表现出较大的遗传多样性,但不同菌株存在着不同程度的亲缘关系。展开更多
文摘Colistin has been regarded as the last line antibiotic for treatment of infections caused by multidrug resistant gram-negative bacteria. Therefore, the increasing emergence of colistin resistance among gram-negative bacteria represents a serious problem. The objective of this study was to characterize the effectiveness of the chemically synthesized thanatin in linear form against colistin-resistant E. coli isolated from a pig farm in China. Agar diffusion assay and broth microdilution test were employed to analyze the susceptibility of colistin-sensitive E. coli (ATCC25922) and colistin-resistant E. coli (SHP45) to linear thanatin (L-thanatin). Combinatory effect of linear thanatin and colistin against E. coli was also determined by fractional inhibition concentration index (FICI) analysis. The results showed that L-thanatin at a concentration of 1 mg/ml produced larger inhibition zone on agar against ATCC25922 than SHP45. In the quantitative microdilution test, L-thanatin had the same MIC of 3.2 μg/ml for ATCC25922 and SHP45. Based on the FICI analysis, additive effect was obtained with 1.56 μg/ml of L-thanatin and 0.125 μg/ml of colistin for ATCC25922;but with 1.56 μg/ml of L-thanatin and 0.25 μg/ml of colistin or with 2 μg/ml of colistin and 0.39 μg/ml of L-thanatin for SHP45. These data proved that L-thanatin is an effective antimicrobial peptide against colistin-resistant E. coli.
文摘为了解河南省焦作市、许昌市规模化养殖厂耐黏菌素大肠杆菌的流行情况,对分离到的32株耐黏菌素大肠杆菌使用微量肉汤稀释法检测其药物敏感性,并采用脉冲场凝胶电泳(Pulsed field gel electrophoresis,PFGE)对分离株进行分型研究。结果显示,32株耐黏菌素大肠杆菌对四环素、多西环素、磺胺异噁唑、复方新诺明的耐药率均高达90%以上,32株猪源大肠杆菌可分为30种带型。结果表明,两地市养殖场猪源大肠杆菌耐药性普遍存在,且以多重耐药为主,PFGE分型结果显示,32株耐黏菌素大肠杆菌整体上表现出较大的遗传多样性,但不同菌株存在着不同程度的亲缘关系。
