| Objectives:This study makes a systematic review of the prevalence of CRE (Carbapenems-Resistant Enterobacteriaceae) in Asia, Europe and America. We have also investigated the prevalence, resistant mechanisms and homology of the carbapenem-resistant Klebsiella pneumonia isolated in the first affiliated hospital of Nanjing Medical University. This study aims to provide basis for the control and treatment of carbapenems-resistant Enterobacteriaceae.Methods:Both Pubmed and Embase databases are used to search for identify qualified papers. Random or fixed-effect models are used to deal with the data. The bacteria gets identified by VITEK2compact or API; Antibiotic susceptibility of 81 CRKP is tested by K-B method; Integrons’ variable regions and the resistance genes are detected by PCR. The homology of the isolated Klebsiella pneumonia is detected by the PFGE (Pulsed Field Gel Electrophoresis) method.Results:As the meta-review illustrated, all the three continents show an increasing trend in the carbapenems resistant rate of Enterobacteriacea during the years of 2000-2011, and America is the region with the highest resistant rate of CRE in recent years (2008-2011). Among all the Enterobacteriaceae strains, Klebsiella. spp shows the highest carbapenems resistant rate over the collected years (2000-2011), namely 1.4%(95%CI 1.0-1.8%), followed by the Citrobacter.spp, Enterobacter.spp, Serratia.spp and Proteus.spp. Carbarpenems resistance in E.coli is still rare with a resistant rate of 0.6%(95% CI 0.4-0.8%). Imipenem resistant rates are slightly higher than meropenem among most of the Enterobacteriaceae genera. Among all the CRE, Klebsiella and E. coli accounted for the largest proportions, namely 44.9% and 23.4%.The proportion of carbapenem-resistant isolates of Klebsiella pneumonia have risen rapidly during 2009-2011 from 1.6% to 11.2%; most of the isolates are resistant to the β-lactams; among 81 isolates,92.6% of them are detected of intI1 and 78.7% of the isolates are detected of variable regions. The most common gene cassette is aadA2, followed by the aacA4-catB8-aadAl and aadA2+dfrA25. The most common genes encoding ESBLs(Extended Spectrum Beta-Lactamases) detected in the CRKP are VEM, CTX and SHV, whose positive rates are 67.9%,51.9 and 65.4% respectively. KPC gene type is the only genes encoding the carbapenemases in this study. Seven gene patterns are obtained by PFE, therefore group A is further divided into A1, A2 and A3, while group B into B1 and B2, and group D into D1, D2.42 (out of 81) isolates belong to group A which indicates that group A is the most common gene type in our hospital.Conclusions:(1) During the years of 2001-2011, the three continents (Asia, America and Europe) have showed increasing trend of the carbapenems resistance in Enterobacteriacea, where America shows the highest resistant rate. Klebsiella. spp shows the highest carbapenems resistant and also accounts for the largest proportion in the CRE. Imipenem shows higher resistant rate than Meropenem in the Enterobacteriacea.(2) The proportion of CRKP has risen rapidly in our hospital, and efficient measures should be carried out to inhibit the dissemination of CRKP; Class I integrons are prevalence in the CRKP, and their isolates have high capability to capture antibiotic resistance gene cassettes. KPC gene is the most common genes encoding carbapenemases in our hospital. An epidemic of CRKP is found in the ICU ward in 2011. More effective approach is urgently needed to control the transmission of CRKP. |
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