Lombardi Fortunata, Gaia Paola, Valaperta Rea, Cornetta Maria, Tejada Milvana Rosa, Di Girolamo Luca, Moroni Alessandra, Ramundo Federica, Colombo Alessio, Valisi Massimiliano, Costa Elena
Research Laboratories-Molecular Biology, IRCCS Policlinico San Donato, San Donato Milanese, 20097 Milan, Italy.
Clinical Microbiology Laboratory, IRCCS Policlinico San Donato, Milan, Italy.
Biomed Res Int. 2015;2015:871947. doi: 10.1155/2015/871947. Epub 2015 May 4.
Frequent use of carbapenems has contributed to the increase to K. pneumoniae strains resistant to this class of antibiotics (CRKP), causing a problem in the clinical treatment of patients. This investigation reports the epidemiology, genetic diversity, and clinical implication of the resistance to drugs mediated by CRKP in our hospital. A total of 280 K. pneumoniae strains were collected; in particular 98/280 (35%) were CRKP. Sequencing analysis of CRKP isolated strains showed that 9/98 of MBL-producing strains carried the bla VIM-1 gene and 89/98 of the isolates were positive for bla KPC-2. Antimicrobial susceptibility tests revealed a complete resistance to third-generation cephalosporins and a moderate resistance to tigecycline, gentamicin, and fluoroquinolones with percentages of resistance of 61%, 64%, and 98%, respectively. A resistance of 31% was shown towards trimethoprim-sulfamethoxazole. Colistin was the most active agent against CRKP with 99% of susceptibility. Clonality was evaluated by PFGE and MLST: MLST showed the same clonal type, ST258, while PFGE analysis indicated the presence of a major clone, namely, pulsotype A. This finding indicates that the prevalent resistant isolates were genetically related, suggesting that the spread of these genes could be due to clonal dissemination as well as to genetic exchange between different clones.
碳青霉烯类药物的频繁使用导致了耐碳青霉烯类肺炎克雷伯菌（CRKP）菌株的增加，给患者的临床治疗带来了问题。本调查报道了我院CRKP介导的耐药性的流行病学、遗传多样性及临床意义。共收集了280株肺炎克雷伯菌菌株；其中98/280（35%）为CRKP。对CRKP分离菌株的测序分析表明，9/98产金属β-内酰胺酶（MBL）的菌株携带bla VIM-1基因，89/98的分离株bla KPC-2呈阳性。药敏试验显示对第三代头孢菌素完全耐药，对替加环素、庆大霉素和氟喹诺酮类药物中度耐药，耐药率分别为61%、64%和98%。对复方新诺明的耐药率为31%。黏菌素是对CRKP活性最强的药物，敏感性为99%。通过脉冲场凝胶电泳（PFGE）和多位点序列分型（MLST）评估克隆性：MLST显示为同一克隆型ST258，而PFGE分析表明存在一个主要克隆，即脉冲型A。这一发现表明流行的耐药菌株具有遗传相关性，提示这些基因的传播可能是由于克隆传播以及不同克隆之间的基因交换。
