【摘要】 目的分析呼吸内科肺炎患者痰液分离鲍曼不动杆菌携带β-内酰胺酶基因及主动外排泵基因情况。方法收集经生化鉴定为醋酸钙-鲍曼不动杆菌复合体的菌株160株,将鲍曼不动杆菌特异性片段（Ab-ITS）的二重PCR法确认为鲍曼不动杆菌者纳入研究。用PCR法检测鲍曼不动杆菌β-内酰胺酶基因和主动外排泵基因,包括A类β-内酰胺酶(bla_TEM、bla_PER和bla_CARB)、B类β-内酰胺酶(bla_IMP和bla_VIM)、C类β-内酰胺酶(bla_ADC和bla_DHA)、D类β-内酰胺酶(bla_OXA-23、bla_OXA-24、bla_OXA-51和bla_OXA-58)和主动外排泵相关基因（adeB、adeJ、macB、emrB、emrA、abeS、abeM和craA）。以微量肉汤稀释法检测加入外排泵抑制剂羰基氰化氯苯腙（CCCP）前后,携带adeB基因鲍曼不动杆菌对亚胺培南的最低抑菌浓度（MIC）的变化。结果临床分离160株醋酸钙-鲍曼不动杆菌复合体中鲍曼不动杆菌143株（占90%）,包括亚胺培南耐药株119株（占83.2%）和敏感株24株（占16.8%）。所有鲍曼不动杆菌均检出bla_OXA-51基因,其中,亚胺培南耐药株中检出bla_OXA-23（98.3%）、bla_TEM（41.4%）、bla_ADC（98.3%）和bla_DHA（0.7%）,bla_PER、bla_CARB、bla_IMP、bla_VIM、bla_OXA-24和bla_OXA-58均未检出;敏感株中未检出bla_OXA-23。adeJ、macB、abeM和craA基因在143株鲍曼不动杆菌中的携带率均为100%;emrB、emrA和abeS基因携带率均超过80%。adeB基因在亚胺培南耐药株中检出117株（98.3%）。在CCCP干预试验中,携带adeB基因的鲍曼不动杆菌MIC₅₀降低1/2。结论呼吸内科鲍曼不动杆菌主要携带bla_OXA-23和adeB主动外排泵基因,可能与亚胺培南耐药密切相关。更多还原

【Abstract】 Objective To investigate the prevalence of β-lactamase genes and active efflux pump genes in Acinetobacter baumannii（A. baumannii） isolated from sputum samples of the patients with pneumonia. Methods A total of 160 strains of A. calcoaceticus-A. baumannii complexes identified by routine biochemical methods and double PCR using A. baumannii specific fragment in internal transcribed spacer（ITS） sequence were collected. The β-lactamase genes and active efflux pump genes in these strains, including class A β-lactamase genes such as bla_TEM, bla_PER and bla_CARB, class B β-lactamase genes such as bla_IMP and bla_VIM, class C β-lactamases genes such as bla_ADC and bla_DHA, class D β-lactamases genes such as bla_OXA-23, bla_OXA-24, bla_OXA-51 and bla_OXA-58 and active efflux pump related genes such as adeB, adeJ, macB, emrB, emrA, abeS, abeM, and craA, were detected by PCR. The minimal inhibitory concentrations（MIC） of imipenem to A. baumannii with adeB gene were measured by the micro-broth dilution method before and after the treatment with the efflux pump inhibitor of carbonyl cyanide chlorpheniramine（CCCP）. Results A total of 143 strains of A. baumannii（143/160, 90%） were isolated from the A. calcoaceticus-A. baumannii complexes. Among them, 119 strains（83.2%） were resistant to imipenem, and the other 24 strains（16.8%） sensitive to imipenem. The bla_OXA-51 gene was detected in all of A. baumannii strains, and bla_OXA-23, bla_TEM, bla_ADC and bla_DHA genes were detected in 98.3%, 41.4%, 98.3% and 0.7% of imipenem-resistant strains, respectively. The bla_PER, bla_CARB, bla_IMP, bla_VIM, bla_OXA-24 and bla_OXA-58 genes were not found. However, the bla_OXA-23 gene was not found in imipenem-sensitive strains. All of 143 strains of A. baumannii carried adeJ, macB, abeM and craA genes, and more than 80% of strains carried emrB, emrA and abeS genes. The adeB gene was detected in 98.3%（117/119） of imipenem-resistant strains. After treated with CCCP, the MIC₅₀ of imipenem to A. baumannii with adeB gene was reduced by 1/2. Conclusion A. baumannii carries bla_OXA-23 and adeB genes, which may be closely related to imipenem resistance.更多还原