Carbapenem-resistant Enterobacteriaceae (CRE) have been reported increasingly in the past 20 years and with a higher prevalence of carbapenemases worldwide. In this study, we collected ninety-one isolates of CRE from a hospital in central Taiwan and all isolates were defined as a minimum inhibitory concentration (MIC) of ?2?mg/L for carbapenem. Polymerase chain reaction (PCR) and nucleotide sequencing showed 89 isolates with carbapenemase genes (97.8%), including OXA-48 (n?=?85), KPC-2 (n?=?19), and IMP-8 (n?=?21), and 24 strains harboring more than one carbapenemase enzymes. Extended-spectrum β-lactamase (ESBL), AmpC β-lactamase and other β-lactamase genes were also detected with high rate. Some strains can transfer β-lactamases genes by conjugation, suggesting that both horizontal transfer and clonal spread may contribute to the increased prevalence of carbapenemase in CRE. The genes of ompK35 and ompK36 mutation or disruption by insertion sequence (IS) elements restored porin protein production in 6 Klebsiella pneumoniae isolates. The gene of ompF and ompC are normal size and no mutation in most Escherichia coli strains. A large variety of genotypes in CRE isolates were found by PFGE grouping, while the
K. pneumoniae and E. coli isolates were clustered into 4 and 7 PFGE groups. Based on the results, the CRE isolates showed significantly high resistance to a broad spectrum of β-lactam due to multiple mechanisms. Carbapenemase OXA-48 was more frequent than KPC-2 and rapidly spread between same or different species. Many virulence factors present in our CRE samples, which play an important role in their effective infection. In K. pneumoniae, the high prevalence of capsule type K64 and K47 were detected, which are a potential target for antibiotic-resistant bacteria treatment. Overall, these data highlight the need for the antibiotic resistance study and the control of antibiotic using.