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目的了解医院耐碳青霉烯类铜绿假单胞菌中整合子的分布及可变区中基因盒的类型与细菌耐药性的关系,为控制医院感染提供依据。方法采用聚合酶链反应(PCR)扩增和琼脂糖凝胶电泳的方法对宁波市医疗中心李惠利医院2012-2014年临床分离的336株耐碳青霉烯铜绿假单胞菌第1、2类整合子进行筛查,并对整合子阳性菌株的可变区序列进行测序分析;采用WHONET5.6和SPSS18.0软件对数据进行统计分析。结果 336株临床菌株中第1类整合子阳性菌株共有42株,阳性率为12.5%;没有筛选到第2类整合子阳性菌株;42株整合子阳性菌株中,23株可变区基因盒为aadA6△-orfd,10株可变区基因盒为aadA6△-ISPa21-aadA6△-orfd,为氨基糖苷类抗菌药物的耐药基因,其余9株可变区未整合基因盒;整合基因盒aadA6△-orfd菌株组阿米卡星、庆大霉素、妥布霉素的耐药率均明显高于未整合基因盒菌株组(P<0.05);而整合基因盒aadA6△-ISPa21-aadA6△-orfd菌株组阿米卡星、庆大霉素、妥布霉素的耐药率介于上述两组之间;42株整合子阳性菌株对阿米卡星、哌拉西林/他唑巴坦、庆大霉素、头孢吡肟、头孢他啶、妥布霉素和左氧氟沙星的耐药率分别为57.1%、73.8%、85.7%、80.9%、95.2%、83.3%和88.1%,均显著高于整合子阴性菌株(P<0.01)。结论耐碳青霉烯类铜绿假单胞菌整合子的携带率相对较低,可变区所携带的耐药基因主要为氨基糖苷类抗菌药物的耐药基因,基因盒与菌株的耐药性呈高度相关,整合子可能还存在着其他机制参与耐药表型的产生。
Objective To understand the distribution of integrants in the hospital carbapenem-resistant Pseudomonas aeruginosa and the relationship between the type of gene cassettes and bacterial resistance in the variable region, so as to provide a basis for the control of nosocomial infections. Methods The polymerase chain reaction (PCR) amplification and agarose gel electrophoresis were used to analyze the clinical isolates of 336 strains of Pseudomonas aeruginosa resistant to carbapenem from 2012 to 2014 in Li Huili Hospital of Ningbo Medical Center. Class integrons were screened and sequenced for variable region sequences of integron-positive strains. Data were analyzed using WHONET 5.6 and SPSS 18.0 software. Results There were 42 positive strains of integron type 1 in 336 strains of clinical isolates, with a positive rate of 12.5%. No class 2 integron-positive strains were screened out. Of the 42 integron-positive strains, 23 were aadA6 △ -orfd, the 10 variable region gene cassettes were aadA6 △ -ISPa21-aadA6 △ -orfd, which were the resistant gene of aminoglycoside antibacterials, and the remaining 9 variable regions did not integrate gene cassettes; the integrated gene cassette aadA6 △ -ISPa21- The resistance rates of amikacin, gentamycin and tobramycin in the -orfd strain were significantly higher than those in the non-integrated gene cassette (P <0.05). However, the integration of aadA6 △ -ISPa21-aadA6 △ - orfd strains amikacin, gentamicin, tobramycin resistance between the two groups; 42 integron-positive strains of amikacin, piperacillin / tazobactam, The resistance rates of gentamycin, cefepime, ceftazidime, tobramycin and levofloxacin were 57.1%, 73.8%, 85.7%, 80.9%, 95.2%, 83.3% and 88.1% Negative strains (P <0.01). CONCLUSION: Carbapenem-resistant Pseudomonas aeruginosa integron has a relatively low carrier rate. The resistance genes carried in the variable region are mainly the resistance genes of aminoglycoside antibiotics, the resistance of the gene cassette and the strain There is a high degree of correlation, integrons may exist other mechanisms involved in the generation of resistant phenotypes.