鲍曼不动杆菌生物膜形成、外膜蛋白OmpA/CarO表达与碳青霉烯类耐药相关研究OA
Correlation between biofilm formation,expression of outer membrane pro-tein OmpA/CarO and carbapenem resistance of Acinetobacter baumannii
目的 探讨鲍曼不动杆菌生物膜形成及其外膜蛋白OmpA、CarO表达,以及与碳青霉烯类抗生素耐药的相关性.方法 采用结晶紫染色法定性定量检测临床分离鲍曼不动杆菌的生物膜形成能力.通过微量肉汤稀释法测定菌株对亚胺培南的最低抑菌浓度(MIC)及生物膜最低抑菌浓度(MBIC).计算 MBIC/MIC比值,比较浮游态与生物膜态菌株的耐药差异.提取亚胺培南耐药菌株在两种状态下的总 RNA,采用荧光定量聚合酶链反应(PCR)检测外膜蛋白OmpA、CarO 基因的相对表达量,分析其对鲍曼不动杆菌碳青霉烯类耐药的可能影响.结果 108株鲍曼不动杆菌中,亚胺培南耐药菌株检出率为61.1%,生物膜阳性菌株检出率为93.5%,其中生物膜弱阳性44株(占43.6%),生物膜中等阳性45株(占44.5%),生物膜强阳性12株(占11.9%).MBIC/MIC值分析显示,无论耐药或敏感菌株,形成生物膜后耐药性均增强:亚胺培南耐药株多数菌株耐药性增加4～8倍,敏感株多数增加2～4倍.荧光定量PCR结果显示,与浮游态相比,生物膜态下鲍曼不动杆菌外膜蛋白OmpA表达量显著升高(t=5.385,P<0.001),外膜孔道蛋白CarO表达量显著降低(t=-4.359,P<0.001).结论 生物膜形成可增强鲍曼不动杆菌对碳青霉烯类药物的耐药性.该过程中OmpA表达上调和CarO表达下调可能是其耐药性增强的重要机制之一.
Objective To investigate the biofilm formation and expression of outer membrane proteins OmpA and CarO of Acinetobacter baumannii(A.baumannii),as well as their correlation with resistance to carbapenem anti-biotics.Methods The crystal violet staining method was used for qualitative and quantitative detection of biofilm forming ability of clinically isolated A.baumannii.The minimum inhibitory concentration(MIC)and minimum biofilm inhibitory concentration(MBIC)of imipenem against the strains were determined by the microdilution broth method.MBIC/MIC values were calculated,difference in drug resistance of bacterial strains in planktonic and biofilm conditions was compared.Total RNA was extracted from imipenem-resistant strains in two conditions,the relative expression levels of outer membrane protein OmpA and CarO genes were detected with fluorescence quanti-tative polymerase chain reaction(qPCR),and their potential impact on carbapenem resistance of A.baumannii was analyzed.Results Among the 108 A.baumannii strains,the detection rate of imipenem-resistant strains was 61.1%,detection rate of biofilm-positive strains was 93.5%,out of which 44(43.6%),45(44.5%)and 12(11.9%)strains showed weak,moderate and strong biofilm positivity,respectively.MBIC/MIC value analysis revealed that,regardless of whether the strains were resistant or sensitive,their resistance all increased after forming biofilm:for imipenem-resistant strains,most showed a 4-to 8-fold increase in resistance,while sensitive strains exhibited a 2-to 4-fold increase.Fluorescence qPCR showed that compared with the planktonic condition,the expression of outer membrane protein OmpA in A.baumannii increased significantly under biofilm condition(t=5.385,P<0.001),the expression of outer membrane porin protein CarO decreased significantly(t=-4.359,P<0.001).Conclusion The formation of biofilm can increase the carbapenem resistance of A.baumannii.The up-regulation of OmpA expression and down-regulation of CarO expression may be one of the key mechanisms of the increase of resistance.
董瑶;关丽娜;王朝莉;冯莉;谢勇恩
川北医学院基础医学与法医学院基础医学研究所,四川 南充 637000||南充市中心医院检验科,四川 南充 637000川北医学院基础医学与法医学院基础医学研究所,四川 南充 637000川北医学院基础医学与法医学院基础医学研究所,四川 南充 637000川北医学院基础医学与法医学院基础医学研究所,四川 南充 637000川北医学院基础医学与法医学院基础医学研究所,四川 南充 637000
医药卫生
鲍曼不动杆菌碳青霉烯类耐药性生物膜外膜蛋白OmpA外膜孔道蛋白CarO
Acinetobacter baumanniicarbapenem resistancebiofilmout membrane proteinOmpAouter membrane porin proteinCarO
《中国感染控制杂志》 2026 (5)
724-729,6
川北医学院国家级项目申报预研项目资助(CBY19-YZ02)
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