摘要
目的研究鲍曼不动杆菌2个多重药物外排泵AdeABC和AdeIJK在临床株中的表达及与耐药的关系。方法微量肉汤稀释法检测鲍曼不动杆菌临床株对9种抗菌药物的敏感性,分别提取临床菌株的DNA和RNA进行adeB、adeJ的PCR及RT-PCR扩增,用凝胶扫描半定量分析外排泵的表达情况。结果22株多重耐药的鲍曼不动杆菌临床株在应用CCCP后,其中3株(13.64%)对头孢他啶的MIC值降至原值的1/4,6株(27.28%)对氧氟沙星的MIC值降至原值的1/4或1/4以下,12株(54.54%)对氯霉素的MIC值降至原值的1/4或1/4以下,22株(100%)对庆大霉素的MIC值降至原值的1/4以下。22株多重耐药临床株和4株敏感株进行基因adeB、adeJ的PCR扩增,均可见预期扩增产物。RT-PCR结果10株多重耐药株为adeB相对表达水平(灰度)1.211～9.169,平均3.897,4株敏感株未检测到adeB的表达。10株多重耐药株为adeJ相对表达水平(灰度)0.956～4.519,平均1.75,4株敏感株为0.356～0.576,平均0.447。结论鲍曼不动杆菌临床株外排泵AdeABC的表达、AdeIJK的高表达可能与耐药性有关。
Objective To study the expression of active efflux pump AdeABC and AdeIJK involved in clinical strains of muhidrug-resistant（MDR） Acinetobacter baumannii. Methods The antimicrobial susceptibilities of 22 Acinetobacter baumannii strains were tested by micro-dilution broth method. The adeB and adeJ gene were amplified by PCR. The expression of adeB and adeJ were examined by RT-PCR, and analyzed by semiquantitative analysis of gel electrophoresis. Results After adding CCCP, all of the MICs values of antibiotics tested, decreased by 25% or more when compared to the formers for instance, 3 strains （13.64%） against ceftazidine; 6 strains （27.28%） against ofloxacin; 12 strains （54.54%） against chloramphenicol and 22 strains （100%） against gentamicin respectively. There were adeB and adeJ gene in 22 MDR strains and 4 sensitive strains. The relative intensity of mRNA expression of adeB in 10 MDR strains was 1.211 - 9. 169 （the average was 3. 897）; the mRNA expression of adeB in 4 sensitive strains were not examined. The relative intensity of mRNA expression of adeJ in 10 MDR strains was 0. 956 - 4. 519 （the average was 1.75）, and those in 4 sensitive strains were 0. 356 -0. 576 （the average was 0. 447）. Conclusion The muhidrug resistance mechanisms of Acinetobacter baumannii include the expression of AdeABC and overexpression of AdeIJK.
出处
《中国抗生素杂志》
CAS
CSCD
北大核心
2009年第5期304-308,I0002,共6页
Chinese Journal of Antibiotics
关键词
鲍曼不动杆菌
多重耐药
外排泵
Acinetobacter baumannii
Muhidrug resistance
Efflux pump
