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Background A carbapenem-resistant hypermucoviscous Klebsiella pneumoniae isolate was recovered from human sputum. Methods Whole genome sequencing of this isolate was carried out to reveal its clonal background, antimicrobial resistance determinants and virulence factors. Virulence assays were performed using wax moth larvae. The transfer of bla NDM-5 between bacterial strains was tested using conjugation. 59 genome assemblies of ST29 K. pneumoniae and 230 IncX3 plasmids regardless of the carriage of resistance gene were employed for phylogenetic analysis, respectively. Results The strain carried a virulence plasmid pVir-SCNJ1 bearing the virulence gene rmpA and exhibited a high virulence in wax moth. This hypervirulent strain belongs to sequence type 29 and carries bla NDM-5 , which is located on a conjugative plasmid, designated pNDM5-SCNJ1, belonging to type IncX3. pNDM5-SCNJ1 was fully sequenced and shows high similarity with pNDM_MGR194, except some deletion inside the IS Aba125 region. Phylogenetic analysis of IncX3 plasmids revealed that although bla NDM-5 can be evolved from bla NDM-1 via point mutations within some IncX3 plasmids, most of bla NDM-5 -carrying IncX3 plasmids probably have acquired bla NDM-5 in multiple events. Conclusions In this study, we characterized a bla NDM-5 -positive hypervirulent K. pneumoniae of sequence type 29 in China. Our results highlight the need for active surveillance on this lineage of carbapenem-resistant K. pneumoniae . Electronic supplementary material The online version of this article (10.1186/s13756-019-0596-1) contains supplementary material, which is available to authorized users.

BackgroundParagonimiasis is a food-borne trematodiasis, a serious public health issue and a neglected tropical disease. Paragonimus skrjabini is a unique species found in China. Unlike paragonimiasis westermani, it is nearly impossible to make a definitive diagnosis for paragonimiasis skrjabini by finding eggs in sputum or feces. Immunodiagnosis is the best choice to detect paragonimiasis skrjabini. There is an urgent need to develop a novel, rapid and simple immunoassay for large-scale screening patients in endemic areas.Methodology/Principal FindingsTo develop a rapid, simple immunodiagnostic assay for paragonimiasis, rabbit anti-human IgG was conjugated to colloidal gold particles and used to detect antibodies in the sera of paragonimiasis patients. The synthesis and identification of colloidal gold particles and antibody-colloidal gold conjugates were performed. The size of colloidal gold particles was examined using a transmission electron microscope (TEM). The average diameter of colloidal gold particles was 17.46 nm with a range of 14.32–21.80 nm according to the TEM images. The formation of antibody-colloidal gold conjugates was monitored by UV/Vis spectroscopy. Excretory-secretory (ES) antigen of Paragonimus skrjabini was coated on nitrocellulose membrane as the capture line. Recombinant Staphylococcus protein A was used to prepare the control line. This rapid gold immunochromatographic strip was assembled in regular sequence through different accessories sticked on PVC board. The relative sensitivity and specificity of the strip was 94.4% (51/54) and 94.1% (32/34) respectively using ELISA as the standard method. Its stability and reproducibility were quite excellent after storage of the strip at 4°C for 6 months.Conclusions/SignificanceImmunochromatographic strip prepared in this study can be used in a rapid one-step immunochromatographic assay, which is instantaneous and convenient.

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