Carbapenemase-producing Klebsiella pneumoniae has recently spread rapidly throughout China. In this study, we characterized a carbapenem-resistant K. pneumoniae isolate that produced both KPC-2 and IMP-4 type carbapenemases. A clinical isolate of K. pneumoniae, resistant to both meropenem and imipenem, was recovered from a urine sample. Antibiotic susceptibility was determined using the broth microdilution method and Etest (bioMérieux, France). Pulsed-field gel electrophoresis and multilocus sequence typing (MLST) were used for gene type analysis. bla (KPC) and the encoding genes of ESBLs and plasmid-mediated AmpC enzymes were polymerase chain reaction (PCR) amplified and sequenced. Plasmids were analyzed by transformation, enzyme restriction and Southern blot. PCR analysis revealed that the isolate was simultaneously carrying bla (KPC-2), bla (IMP-4), bla (TEM-1), and bla (OKP-B) genes. MLST assigned the isolate to a novel sequence type, ST476. bla (KPC-2)-harbouring plasmids of the isolate and comparative strains had similar EcoRI and HindIII restriction maps, while IMP-4-harbouring plasmids had variable HindIII restriction maps. Coexistence of bla (KPC-2) and bla (IMP-4) was probably due to bla (IMP-4)-harbouring plasmid transmission into KPC-2-producing K. pneumoniae (ST476). The concomitant presence of these genes is alarming and poses both therapeutic and infection control problems.

Loss of the RASSF2A expression induced by methylation-mediated silencing has been reported in several human cancers, but the methylation status of RASSF2A in hepatocellular carcinoma (HCC) is rarely studied so far. In this study, we investigated the RASSF2A expression and its methylation status in a cohort of 45 hepatitis B virus-associated HCC tissues and their adjacent non-carcinoma tissues by using RT-PCR and MS-PCR. Promoter methylation of RASSF2A was found in 31 (68.9%) out of 45 HCC tissues and 12 (40%) out of 30 adjacent normal tissues, respectively (P<0.05). The methylation status of PASSF2A was closely associated with the loss of RASSF2A expression and elevated serum alpha-fetoprotein level, but not significantly with clinical stage, hepatic fibrosis and K-ras mutation. It was concluded that aberrant methylation of the RASSF2A gene with the subsequent loss of RASSF2A expression plays an important role in the pathogenesis of HCC.

The relationship between Ala/Ser polymorphism in 133 codon of exon 3 region of the RASSF1 gene and genetic susceptibility of lung cancer in Hubei province Han population was investigated by a case-control study. Polymerase chain reaction-restriction fragment length polymorphism (PCR-RFLP) technique was adopted to analyze the polymorphism of codon 133 of exon 3 in the RASSF1 gene of 100 pathologically diagnosed lung cancer patients, and 100 healthy controls. The relationship between different genotypes and the susceptibility of lung cancer was analyzed. Among 200 blood samples from Han people in Hubei Province, including 100 from lung cancer patients and 100 from healthy controls, the frequencies of Ala/Ala, Ala/Ser, Ser/Ser genotype of the RASSF1 in lung cancer patients were 83%, 16%, 1%, and those in healthy controls was 93%, 7%, 0% respectively, with the difference being statistically significant between two groups (P<0.05). The individuals with Ala/Ser genotype had higher risk of suffering from lung cancer, with an OR of 2.341, and 95% CI of 1.009-6.393 respectively. It was concluded that RASSF1Ala133Ser was a susceptible genetic factor of lung cancer. Ala/Ser genotype increased the risk of lung cancer.

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