No abstract

No abstract

Background The emergence of carbapenem-resistant Enterobacteriaceae strains has posed a severe threat to public health in recent years. The mobile elements carrying the New Delhi metallo-β-lactqtamase (NDM) gene have been regarded as the major mechanism leading to the rapid increase of carbapenem-resistant Enterobacteriaceae strains isolated from clinics and animals. Results We describe an NDM-5-producing Escherichia coli strain, ECCRA-119 (sequence type 156 [ST156]), isolated from a poultry farm in Zhejiang, China. ECCRA-119 is a multidrug-resistant (MDR) isolate that exhibited resistance to 27 antimicrobial compounds, including imipenem and meropenem, as detected by antimicrobial susceptibility testing (AST). The complete genome sequence of the ECCRA-119 isolate was also obtained using the PacBio RS II platform. Eleven acquired resistance genes were identified in the chromosome; four were detected in plasmid pTB201, while six were detected in plasmid pTB202. Importantly, the carbapenem-resistant gene bla NDM-5 was detected in the IncX3 plasmid pTB203. In addition, seven virulence genes and one metal-resistance gene were also detected. The results of conjugation experiments and the transfer regions identification indicated that the bla NDM-5 -harboring plasmid pTB203 could be transferred between E. coli strains. Conclusions The results reflected the severe bacterial resistance in a poultry farm in Zhejiang province and increased our understanding of the presence and transmission of the bla NDM-5 gene. Electronic supplementary material The online version of this article (10.1186/s12866-019-1454-2) contains supplementary material, which is available to authorized users.

No abstract

The coordination compound Eu(DAF)2(NO3)3 (1, DAF = 4,5‐diazafluorene), which shows strong red fluorescence, has been synthesized and characterized. The luminescence‐quenching effect of 1 has been applied to the detection of water in CH3CN. For the first time, the response mechanism has been uncovered through the confirmation of the structure of the resultant nonluminous compound [Eu(NO3)2(H2O)5](NO3)(DAF)2·H2O (2). The replacement of the coordinated DAF ligands by the added water led to quenching of the emission of the EuIII ion and the simultaneous enhancement of the ligand emission. X‐ray powder diffraction and thermogravimetric analyses also confirmed this mechanism. Theoretical calculations by the semi‐empirical method revealed the origin of the absorption spectra of 1. This fluorometric detection of trace amounts of water in CH3CN by 1 is a direct, rapid, and sensitive method.