The bactericidal activities of two series of quaternary Gemini surfactants have been examined by the suspension quantitative germicidal tests against Escherchia, Staphylococcus aureus and Candida alibicans respectivel...The bactericidal activities of two series of quaternary Gemini surfactants have been examined by the suspension quantitative germicidal tests against Escherchia, Staphylococcus aureus and Candida alibicans respectively, the dodecyltrimethylammonium bromide(C 12TABr) was used for comparison. All of the quaternary Gemini surfactants showed superior bactericidal activities to C 12TABr due to higher densities in both headgroup charge and alkyl chains.展开更多
In this study, bacteriophage of an antibiotic-resistant Escherchia coil strain isolated from feces of chicken was isolated. Its host range was determined by the method of spotting sample on monolayer agar, and its lys...In this study, bacteriophage of an antibiotic-resistant Escherchia coil strain isolated from feces of chicken was isolated. Its host range was determined by the method of spotting sample on monolayer agar, and its lysis titer, optimal multiplicity of infection （MOI）, temperature tolerance and pH tolerance were determined by the double-layer agar plate method. The results showed that the bacteriophage had a broad host range. The biological assay demonstrated that two strains of E. coil were fully lysed and one strain of E. coil was weakly lysed by the bacteriophage. The lysis titer and MOI of the bacteriophage were 1.20×10^8 PFU/ml and 1, respec- tively. Under the optimum temperature of 40℃, the Jysis titer of the bacteriophage reached 8.90×10^9 PFU/ml; however, the bacteriophage lost its infectivity at the tem- perature of 80℃. In the pH range of 5-11, the lysis titer of the bacteriophage ranged from10^6 to 10^9 PFU/mI. Under the condition of pH 4 and 12, the bacterio- phage was invalid.展开更多
目的了解上世纪90年代以来我国部分地区禽源大肠杆菌和沙门菌分离株对1-4代喹诺酮类药物耐药情况。方法血清型采用常规的凝集试验进行测定;药敏纸片试验采用CLSI(clinical and laboratory standards institute)推荐的K-B药敏纸片法。结...目的了解上世纪90年代以来我国部分地区禽源大肠杆菌和沙门菌分离株对1-4代喹诺酮类药物耐药情况。方法血清型采用常规的凝集试验进行测定;药敏纸片试验采用CLSI(clinical and laboratory standards institute)推荐的K-B药敏纸片法。结果344株禽源大肠杆菌分离株覆盖了27个血清型,其中O78、O2、O1和O18血清型菌株分别有141、47、27和22株,共237株,占定型菌株的68.90%;224株禽源沙门菌经血清型鉴定均为鸡白痢沙门菌。1993-1999年禽源大肠杆菌分离株仅对萘啶酸的耐药率超过60%(62.43%,113/181);2000-2008年禽源大肠杆菌分离株对1-3代9种喹诺酮类药物的耐药率均超过60%;禽源沙门菌从2000年起开始出现喹诺酮类耐药菌株,2000-2008年分离到的沙门菌对萘啶酸的耐药率达到了83.74%,但对其它喹诺酮类抗生素的耐药率相对较低。结论近20年来,我国禽源大肠杆菌和沙门菌对喹诺酮类药物的耐药性不断上升,10种喹诺酮类药物之间存在着不同程度的交叉耐药性,且禽源大肠杆菌比沙门菌对喹诺酮类药物的耐药性更为严重,交叉耐药情况亦更为复杂。展开更多
从我国部分地区病、死家禽中分离到大肠埃希菌403株。按照CLSI(clinical and laboratory standards institute)推荐的K-B药敏纸片法对其中的344株分离株进行药敏纸片试验;根据GenBank上发表的序列,设计并合成了五对引物,对所有分离细菌...从我国部分地区病、死家禽中分离到大肠埃希菌403株。按照CLSI(clinical and laboratory standards institute)推荐的K-B药敏纸片法对其中的344株分离株进行药敏纸片试验;根据GenBank上发表的序列,设计并合成了五对引物,对所有分离细菌进行质粒介导的喹诺酮类药物耐药基因的扩增:qnrA、qnrB、qnrS、aac(6′)-ib-cr和qepA。1993年-1996年禽源大肠埃希菌分离株仅对萘啶酸的耐药率超过60%;2001年-2008年禽源大肠埃希菌分离株对1-3代7种喹诺酮类药物的耐药率均超过58%。在403株禽源大肠埃希菌中共检出3(0.7%)株qnrB阳性菌株,2(0.5%)株qnrS阳性菌株,5(1.2%)株aac(6′)-ib-cr阳性菌株以及5(1.2%)株qepA阳性菌株,未检测到qnrA阳性菌株。结果显示,近20年来,我国禽源大肠埃希菌对喹诺酮类药物的耐药性不断上升,同时,质粒介导的喹诺酮类药物耐药基因在禽源大肠埃希菌中呈不断上升的流行趋势。展开更多
文摘The bactericidal activities of two series of quaternary Gemini surfactants have been examined by the suspension quantitative germicidal tests against Escherchia, Staphylococcus aureus and Candida alibicans respectively, the dodecyltrimethylammonium bromide(C 12TABr) was used for comparison. All of the quaternary Gemini surfactants showed superior bactericidal activities to C 12TABr due to higher densities in both headgroup charge and alkyl chains.
基金Supported by Special Fund for Ocean and Fisheries Science Technology and Industrial Development of Guangdong Province(A201508A05)~~
文摘In this study, bacteriophage of an antibiotic-resistant Escherchia coil strain isolated from feces of chicken was isolated. Its host range was determined by the method of spotting sample on monolayer agar, and its lysis titer, optimal multiplicity of infection （MOI）, temperature tolerance and pH tolerance were determined by the double-layer agar plate method. The results showed that the bacteriophage had a broad host range. The biological assay demonstrated that two strains of E. coil were fully lysed and one strain of E. coil was weakly lysed by the bacteriophage. The lysis titer and MOI of the bacteriophage were 1.20×10^8 PFU/ml and 1, respec- tively. Under the optimum temperature of 40℃, the Jysis titer of the bacteriophage reached 8.90×10^9 PFU/ml; however, the bacteriophage lost its infectivity at the tem- perature of 80℃. In the pH range of 5-11, the lysis titer of the bacteriophage ranged from10^6 to 10^9 PFU/mI. Under the condition of pH 4 and 12, the bacterio- phage was invalid.
文摘目的了解上世纪90年代以来我国部分地区禽源大肠杆菌和沙门菌分离株对1-4代喹诺酮类药物耐药情况。方法血清型采用常规的凝集试验进行测定;药敏纸片试验采用CLSI(clinical and laboratory standards institute)推荐的K-B药敏纸片法。结果344株禽源大肠杆菌分离株覆盖了27个血清型,其中O78、O2、O1和O18血清型菌株分别有141、47、27和22株,共237株,占定型菌株的68.90%;224株禽源沙门菌经血清型鉴定均为鸡白痢沙门菌。1993-1999年禽源大肠杆菌分离株仅对萘啶酸的耐药率超过60%(62.43%,113/181);2000-2008年禽源大肠杆菌分离株对1-3代9种喹诺酮类药物的耐药率均超过60%;禽源沙门菌从2000年起开始出现喹诺酮类耐药菌株,2000-2008年分离到的沙门菌对萘啶酸的耐药率达到了83.74%,但对其它喹诺酮类抗生素的耐药率相对较低。结论近20年来,我国禽源大肠杆菌和沙门菌对喹诺酮类药物的耐药性不断上升,10种喹诺酮类药物之间存在着不同程度的交叉耐药性,且禽源大肠杆菌比沙门菌对喹诺酮类药物的耐药性更为严重,交叉耐药情况亦更为复杂。
文摘从我国部分地区病、死家禽中分离到大肠埃希菌403株。按照CLSI(clinical and laboratory standards institute)推荐的K-B药敏纸片法对其中的344株分离株进行药敏纸片试验;根据GenBank上发表的序列,设计并合成了五对引物,对所有分离细菌进行质粒介导的喹诺酮类药物耐药基因的扩增:qnrA、qnrB、qnrS、aac(6′)-ib-cr和qepA。1993年-1996年禽源大肠埃希菌分离株仅对萘啶酸的耐药率超过60%;2001年-2008年禽源大肠埃希菌分离株对1-3代7种喹诺酮类药物的耐药率均超过58%。在403株禽源大肠埃希菌中共检出3(0.7%)株qnrB阳性菌株,2(0.5%)株qnrS阳性菌株,5(1.2%)株aac(6′)-ib-cr阳性菌株以及5(1.2%)株qepA阳性菌株,未检测到qnrA阳性菌株。结果显示,近20年来,我国禽源大肠埃希菌对喹诺酮类药物的耐药性不断上升,同时,质粒介导的喹诺酮类药物耐药基因在禽源大肠埃希菌中呈不断上升的流行趋势。
