Convergence of plasmid-mediated Colistin and Tigecycline resistance in Klebsiella pneumoniae.

Objective: The co-occurrence of colistin and tigecycline resistance genes in Klebsiella pneumoniae poses a serious public health problem. This study aimed to characterize a K. pneumoniae strain, K82, co-harboring a colistin resistance gene (CoRG) and tigecycline resistance gene (TRG), and, importantly, investigate the genetic characteristics of the plasmid with CoRG or TRG in GenBank. Methods: K. pneumoniae strain K82 was subjected to antimicrobial susceptibility testing, conjugation assay, and whole-genome sequencing (WGS). In addition, comparative genomic analysis of CoRG or TRG-harboring plasmids from K82 and GenBank was conducted. K. pneumoniae strain K82 was resistant to all the tested antimicrobials including colistin and tigecycline, except for carbapenems. Results: WGS and bioinformatic analysis showed that K82 belonged to the ST656 sequence type and carried multiple drug resistance genes, including mcr-1 and tmexCD1-toprJ1, which located on IncFIA/IncHI2/IncHI2A/IncN/IncR-type plasmid pK82-mcr-1 and IncFIB/IncFII-type plasmid pK82-tmexCD-toprJ, respectively. The pK82-mcr-1 plasmid was capable of conjugation. Analysis of the CoRG/TRG-harboring plasmid showed that mcr-8 and tmexCD1-toprJ1 were the most common CoRG and TRG of Klebsiella spp., respectively. These TRG/CoRG-harboring plasmids could be divided into two categories based on mash distance. Moreover, we found an IncFIB/IncHI1B-type plasmid, pSYCC1_tmex_287k, co-harboring mcr-1 and tmexCD1-toprJ1. To the best of our knowledge, this is the first report on the co-occurrence of mcr-1 and tmexCD1-toprJ1 on a single plasmid. Conclusion: Our research expands the known diversity of CoRG and TRG-harboring plasmids in K. pneumoniae. Effective surveillance should be implemented to assess the prevalence of co-harboring CoRG and TRG in a single K. pneumoniae isolate or even a single plasmid.

Notch-regulated ankyrin-repeat protein is a novel tissue biomarker that predicts poor prognosis in non-small cell lung cancer.

Notch-regulated ankyrin-repeat protein (NRARP) has recently been reported to be involved in a number of malignant cancers; however, its role in non-small lung cancer (NSCLC) remains unclear. The present study aimed to identify whether NRARP could be applied as a novel prognostic marker for NSCLC. A total of 108 NSCLC patients were enrolled in the present study and their lung tissues were collected. Reverse-transcription quantitative polymerase chain reaction and immunohistochemical staining were used to assess the mRNA and protein levels of NRARP. Appropriate statistical tests were performed to evaluate the associations between NRARP protein expression and clinicopathological features and prognosis in NSCLC patients. The results revealed that NRARP expression was significantly associated with tumor differentiation (P=0.001), Tumor-Node-Metastasis stage (P=0.004) and cigarette smoking (P<0.001). Furthermore, patients with higher NRARP protein expression had significantly shorter overall survival times (P<0.001). Multivariate analysis indicated that overexpression of NRARP protein could be applied as an independent prognostic biomarker for NSCLC. In summary, the present study demonstrated that NRARP protein is overexpressed in NSCLC and that high NRARP expression is correlated with tumor progression and overall survival time. These data indicated the potential value of NRARP as a novel therapeutic target for the treatment of NSCLC.

[Circulating miR-152 helps early prediction of postoperative biochemical recurrence of prostate cancer].

OBJECTIVE: To investigate the value of circulating miR-152 in the early prediction of postoperative biochemical recurrence of prostate cancer. METHODS: Sixty-six cases of prostate cancer were included in this study, 35 with and 31 without biochemical recurrence within two years postoperatively, and another 31 healthy individuals were enrolled as normal controls. The relative expression levels of circulating miR-152 in the serum of the subjects were detected by qRT-PCR, its value in the early diagnosis of postoperative biochemical recurrence of prostate cancer was assessed by ROC curve analysis, and the correlation of its expression level with the clinicopathological parameters of the patients were analyzed. RESULTS: The expression of circulating miR-152 was significantly lower in the serum of the prostate cancer patients than in the normal controls (t = －5.212, P = 0.001), and so was it in the patients with than in those without postoperative biochemical recurrence (t = －5.727, P = 0.001). The ROC curve for the value of miR-152 in the early prediction of postoperative biochemical recurrence of prostate cancer showed the area under the curve (AUC) to be 0.906 (95% CI: 0.809－0.964), with a sensitivity of 91.4% and a specificity of 80.6%. The expression level of miR-152 was correlated with the Gleason score, clinical stage of prostate cancer, biochemical recurrence, and bone metastasis (P <0.05), decreasing with increased Gleason scores and elevated clinical stage of the malignancy. No correlation, however, was found between the miR-152 expression and the patients' age or preoperative PSA level (P >0.05). CONCLUSIONS: The expression level of circulating miR-152 is significantly reduced in prostate cancer patients with biochemical recurrence after prostatectomy and could be a biomarker in the early prediction of postoperative biochemical recurrence of the malignancy.

[Prokaryotic expression, purification, and identification of recombinant human IL-11 protein].

A DNA fragment encoding recombinant human interleukin 11 (hrIL-11) was obtained by PCR from previously constructed pET24a-hrIL-11 plasmid. Then pET21a-hrIL-11 expression vector was constructed routinely and transformed into BL-21(DE3). By the induction of Isopropyl-1-thio-beta-D-galactoside (IPTG), hrIL-11 protein was highly expressed at about 20% of the total bacterial proteins and was identified by Western blot. After purification with Ni-NTA affinity chromatography and refolding with renaturation buffer, the purity of the target hrIL-11 protein reached 95% and its biology activity was 1 x 10(6) IU/mg, determined by stimulating the proliferation of T1165, which facilitates further researches into effects of IL-11 on platelet proliferation and other function.