Background: Carbapenem-resistant Klebsiella pneumoniae (CRKP) appeared recently and now presents a particularly critical problem to hospitalized patients worldwide. We aim to investigate the epidemiology and the risk factors for CRKP colonization and infections, and to evaluate the application performance of MALDI-TOF MS in clustering CRKP.

Results: CRKP colonization and infections incidence was 2.7 (35/1,319,427) per 100,000 patient-days. Inpatients in CRKP group had higher medical expense than CSKP group. Inpatients with underlying conditions, particularly with pulmonary diseases, and with antimicrobial use prior to culture within 30 days, especially with carbapenem use, were risk factors for CRKP acquisition. All CRKP isolates were detected producing KPC-2. The MALDI-TOF MS system and PFGE system provided similar results, with a good concordance between the two methods (adjusted Rand's coefficient, 0.846) and a high probability of MALDI-TOF MS to predict PFGE results (Wallace coefficient, 0.908).

Conclusions: Underlying conditions, particularly pulmonary diseases, and antimicrobial use prior to culture within 30 days, especially carbapenem use, are risk factors for CRKP acquisition. Bla_KPC−2 is the mainstream gene of CRKP in our geographic area of analysis. As only simple sample preparation is needed and the results can be obtained in a short time, MALDI-TOF MS may be considered a probable alternative to PFGE in clustering KPC-2-producing CRKP.

背景： 耐碳青霉烯 肺炎克雷伯菌（CRKP）最近出现，现在对全世界住院患者提出了特别关键的问题。我们旨在调查流行病学和CRKP定植和感染的危险因素，并评估MALDI-TOF MS在CRKP聚类中的应用性能。

结果：CRKP的定植和感染发生率为每100,000个患者日2.7（35 / 1,319,427）。CRKP组住院患者的医疗费用高于CSKP组。患有基础疾病（特别是患有肺部疾病）且在培养前30天内使用抗菌药物（尤其是使用碳青霉烯）的住院患者是获得CRKP的危险因素。检测到所有CRKP分离物均产生KPC-2。MALDI-TOF MS系统和PFGE系统提供了相似的结果，两种方法之间具有很好的一致性（兰德系数调整后为0.846），而MALDI-TOF MS预测PFGE结果的可能性很高（华莱士系数为0.908）。

结论： 基础条件（尤其是肺部疾病）和30天内培养前使用抗菌药物（尤其是碳青霉烯）是CRKP获得的危险因素。 布拉_KPC在我们的分析地理区域，₋₂是CRKP的主流基因。由于仅需要简单的样品前处理即可在短时间内获得结果，因此在将生产KPC-2的CRKP成簇时，可以将MALDI-TOF MS视为PFGE的可能替代品。