非鲍曼的不动杆菌的临床分布特征及耐药机制分析

Clinical distribution and antibiotics resistance mechanisms of non-baumannii Acinetobacter

目的分析临床分离的非鮑曼不动杆菌的临床分布特征及药敏情况;检测其金属β-内酰胺酶和整合酶基因。方法用K-B法对安徽省2家教学医院病房及门诊收集的各种标本分离出的非鲍曼不动杆菌进行药物敏感试验,按CLSI 2016版判断结果。用聚合酶链式反应(PCR)对其进行扩增金属β-内酰胺酶基因及Ⅰ-Ⅲ类整合子的整合酶基因,分析结果。结果44株非鲍曼不动杆菌(洛菲不动杆菌29株、琼氏不动杆菌9株、醋酸钙不动杆菌3株、溶血不动杆菌2株及不动杆菌基因型13TU 1株),来源于心内科、呼吸内科等临床科室,分离于痰液、尿液、分泌物及其他标本。其中3株为多药耐药菌株(2株洛菲不动杆菌及1株溶血不动杆菌),17株仅对β-内酰胺类抗生素耐药,余24株为完全敏感菌株。金属β-内酰胺酶SIM-1阳性率为20.45%(7株洛菲不动杆菌、2株琼氏不动杆菌);VIM-2阳性率为9.09%(2株洛菲不动杆菌、1株溶血不动杆菌及1株琼氏不动杆菌);IMP-4、NDM-1均未检测出。IntI-1阳性率为11.36%(3株洛菲不动杆菌、1株溶血不动杆菌及1株琼氏不动杆菌);IntI-2阳性率为13.64%(3株洛菲不动杆菌、1株溶血不动杆菌及2株琼氏不动杆菌);IntI-3未检测出。结论非鲍曼不动杆菌的耐药率相对较低,但已经发现多药耐药菌株;其耐药机制可能与金属β-内酰胺酶及整合酶有关。

Objective To analyze the clinical distribution characteristics and drug sensitivity of non-baumanii Acineto-bacter(NbA)isolates,and to detect metallo-B-lactamases and integrase genes.Methods K-B method was used to test the drug sensitivity of non-baumannii Acinetobacter isolated from various specimens collected from wards and clinics of two teaching hospitals in Anhui Province.The results were judged according to CLSI 2016 edition.Polymerase chain reaction(PCR)was used to amplify the metallo B-lactamase gene and the integrase gene of class Ⅰ-Ⅲ integrin.Results To-tal 44 NbA isolates(29 A.lwofi strains,9 A.junii strains,2 A.haemolyticus strains,3 A.calcoceticus strains and 1 Acinetobacter genomic species 13TU strain)were potentially gathered in Cardiology Department,Respiratory Department and others,and isolated from sputum,urine,secretion and other samples.Three(6.8%)isolates(2 A.luffi strains,1 A.haemolyticus strain)were multi-resistant,17 strains(38.6%)were susceptible to all antimicrobial agents exceptβ-lactam antibiotics,while the rest 24 isolates were fully susceptible.Nine of the 44(20.45%)NbA isolates carried SIM-;I gene,including 7 A.lwoffi strains and 2 A.junii strains.Four strains(9.09%)carried VIM-2 gene,including 2 A.lofi strains,1 A.haemolyticus strain and 1 A.junii strain.IMP4,NDM-1 gene were not detected in all NbA strains.Five(11.36%)harbored Class 1 integrase,ineluding 3 A.luoffi strains,1 A.haemolyticus strain and 1 A.junii strain,6(13.64%)isolates harbored class 2 integrase,including 3 A.lhoffi strains,1 A.haemolyticus strain and 2 A.junii strains.No class 3 integrase were found in all the NbA isolates.Conclusion The drug resistance rate of non-bau-manni Acinetobacter is relatively low,but multidrug-resistant strains have been found.The mechanism of drug resistance may be related to metallo-B-lactamase and integrase.