血流感染泛耐药鲍曼不动杆菌耐药和基因型分析

Genotyping of pan drug-resistant Acinetobacter baumannii in bloodstream infections

目的分析血流感染泛耐药鲍曼不动杆菌基因,指导临床疾病治疗及耐药性控制。方法从2013-2017年医院血流感染患者中分离泛耐药鲍曼不动杆菌,同一患者取首株。鉴定菌株并进行药敏试验,采用PCR进行基因检测。结果 2013-2017年检出血流感染泛耐药鲍曼不动杆菌共72株,各年份检出菌株数分别为4、7、13、21和27株,构成情况分别为5.56%、9.72%、18.06%、29.17%和37.50%。医院监护室、中心重症监护室、呼吸内科监护室、神经外科监护室、神经内科监护室、非监护室、肝胆外科、烧伤/整形科血流感染患者分别分离出19、11、9、6、5、5、4和3株,构成比分别为26.39%、15.28%、12.50%、8.33%、6.94%、6.94%、5.56%和4.17%;神经内科、胃肠外科、血管外科各2株,胸外科、肾脏内科、泌尿外科、神经外科各1株。泛耐药鲍曼不动杆菌对米诺环素、加替沙星耐药率分别为45.83%(33/72)、58.33%(42/72),对头孢他啶、头孢替坦、头孢曲松、头孢吡肟、庆大霉素、环丙沙星、阿米卡星、妥布霉素、头孢哌酮/舒巴坦的耐药率均为100.00%,对替加环素和多粘菌素B仍敏感,耐药率为0。aac(3)-I、aac(6′)-Ib、armA检出率分别为51.39%、31.94%和26.39%;blaTEM、blaSHV、blaCTX、blaIPM、blaVIM、OXA-23、OXA-51、ant(3′′)-I、aph3′-I、rmtB、carO缺失、adeB、adeG基因的检出率均为100.00%。结论血流感染泛耐药鲍曼不动杆菌检出情况逐年增加,尤其是监护室,临床治疗时可优先选用替加环素和多粘菌素B。控制耐药基因传播,可以从源头上控制泛耐药菌株传播,改善治疗效果。

Objective Genes of pan drug-resistant Acinetobacter baumannii causing a bloodstream infection were analyzed in order to guide the treatment of those infections in clinical settings and to control the drug resistance of A.baumannii. Methods Pan drug-resistant A.baumannii was isolated from patients with a bloodstream infection at this Hospital.The initial isolate from the same patient was genotyped.The strains were identified and their drug resistance was analyzed.DNA was extracted,and genes were detected using PCR.Results In total,72 strains of pan drug-resistant A.baumannii were detected from 2013-2017.Four strains（5.56%）were isolated in 2013,7（9.72%）were isolated in2014,13（18.06%）were isolated in 2015,21（29.17%）were isolated in 2016,and 27（37.50%）were isolated in 2017.Nineteen strains（26.39%）of pan drug-resistant A.baumannii were isolated from patients in wards,11（15.28%）were isolated from patients in the central intensive care unit,9（12.50%）were isolated from patients in the Respiratory Medicine ward,6（8.33%）were isolated from patients in the Neurosurgery ward,5（6.94%）were isolated from patients in the Neurology ward,5（6.94%）were isolated from patients not in wards,4（5.56%）were isolated from patients in Hepatobiliary Surgery,and 3（4.17%）were isolated from patients in Burns/Plastic Surgery.Two strains（2.78%）were isolated from patients in Neurology,2（2.78%）were isolated from patients in Gastrointestinal Surgery,2（2.78%）were isolated from patients in Vascular Surgery,1（1.39%）was isolated from patients in Thoracic Surgery,1（1.39%）was isolated from patients in Nephrology,1（1.39%）was isolated from patients in Urology,and 1（1.39%）was isolated from patients in Neurosurgery.The resistance of pan drug-resistant A.baumannii to minocycline was 45.83%,its resistance to gatifloxacin was 58.33%,its resistance to cephalosporin was 100.00%,its resistance to cefotetan was 100.00%,its resistance to ceftriaxone was 100.00%,its resistance to cefepime was 100.00%,its resistance to gentamicin was 100.00%,its resistance to ciprofloxacin was 100.00%,its resistance to ciprofloxacin was 100.00%,its resistance to amikacin was 100.00%,its resistance to tobramycin was 100.00%,and its resistance to cefoperazone/sulbactam was 100.00%,but it was still sensitive to tigecycline and polymyxin B.The blaTEM gene was detected in 100.00% of isolates,blaSHV was detected in 100.00%,blaCTX was detected in 100.00%,blaIPM was detected in 100.00%,blaVIM was detected in100.00%,OXA-23 was detected in 100.00%,OXA-51 was detected in 100.00%,aac（3）-I was detected in 51.39%,aac（6′）-Ib was detected in 100.00%,,ant（3′′）-I was detected in 100.00%,aph3′-I was detected in 26.39%,armA was detected in 100.00%,rmtB was detected in 31.94%,the loss of carO was detected in 100.00%,adeB was detected in100.00%,and adeG was detected in 100.00%. Conclusion Pan drug-resistant A.baumannii was increasingly detected in bloodstream infections,and especially in wards.Tigecycline and polymyxin B should be the treatment of choice when treating an infection with that bacterium.Controlling the spread of drug resistance genes should control the spread of pan drug-resistant strains from their source and improve the effectiveness of treatment.