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Objective:To analyze the characteristics of drug resistance genes in a Klebsiella pneumoniae strain coproducing carbapenemases KPC-2 and NDM-5. Methods:Klebsiella pneumoniae KPN-hnqyy was separated from the stool specimen of a patient in the Hematology Department of Affiliated Cancer Hospital of Zhengzhou University. The strain was identified with a BD Phenix-M50 automated microbiology system and the minimum inhibitory concentration against the strain was measured as well. The genotypes of the carbapenemases were tested by enzyme immunochromatographic assay and PCR method. The transferability of related plasmids was analyzed by conjugation test. Whole-genome sequencing of the strain was conducted using PacBio and Illumina platforms. The MLST type, resistance gene and plasmid type of the strain were retrieved in BacWGSTdb. The genome and open reading frame sequence of the strain were compared using Easyfig_2.2.3. Visual cycle graphs were generated using BRIG v0.95. Results:Klebsiella pneumoniae KPN-hnqyy was resistant to carbapenem antibiotics. It belonged to ST11 and carried two carbapenemase genes of blaKPC-2 and blaNDM-5. The conjugant only harbored the blaKPC-2 gene. Whole-genome sequencing revealed that the strain contained one chromosome and three plasmids. Its chromosome genome shared more than 99.9% similarity with that of Klebsiella pneumonia KP69 and KP19-2029. Moreover, a similar IncR and IncFⅠ resistance gene fusion region was contained in different types of plasmids carried by them: the blaKPC-2 gene was located in a structure—which evolved from the Tn3-△Tn4401-Tn1721/Tn1722 sequence—inside this fusion region with its ends inserted into the transposase IS26 gene; the blaNDM-5 gene was located on a transposon containing the special plasmids of the insertion fragment in phages, with its ends inserted into the transposase IS26 gene too. Conclusions:The IncR and IncFⅡ resistance gene fusion region of blaKPC-2 carried by Klebsiella pneumoniae ST11 might be widely coexistent with the chromosomal genome. The blaNDM-5 gene carried by special plasmids might be accidentally obtained through gene recombination mediated by transposable element IS26. The wide transmission of Klebsiella pneumoniae ST11 carrying the blaKPC-2 gene in China and its ability to obtain other carbapenemase genes through transposable element IS26 were well worth attention.
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Objective:To explore the expression and clinical significance of KIF20A in HER2-positive breast cancer.Methods:The clinicopathological characteristics of 82 cases of HER2-positive breast cancer were retrospectively analyzed. The expression of KIF20A in tissues was detected by immunohistochemical method, and the expression of KIF20A in HER2 overexpression breast cancer and its relationship with clinicopathological characteristics were analyzed. The mRNA level of KIF20A in HER2-positive breast cancer tissues and normal tissues adjacent to cancer were analyzed by bioinformatics methods.Results:The positive expression of KIF20A was in the nucleus, forming brown-yellow particles. In HER2-positive breast cancer tissues, the positive high expression rate of KIF20A is 57.3%, while it is mainly low or no expression in the adjacent tissues. The high expression of KIF20A is significantly correlated with tumor size and pTNM stage, while the correlation with age and tumor grade is not statistically significant. The results of bioinformatics analysis suggest that the high expression of KIF20A in invasive breast cancer is significantly related to poor disease-free survival.Conclusions:KIF20A is abnormally expressed in HER2-positive breast cancer, which is related to the tumor grade and pTNM stage of HER2 overexpression breast cancer, and the high expression of KIF20A indicates a poor prognosis.
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Objective:To analyze the characteristics of plasmids in KPC-2-producing Serratia marcescens ( S. marcescens) isolates. Methods:Four carbapenem-resistant S. marcescens strains were isolated from four patients admitted to the hepatobiliary ward of Affiliated Cancer Hospital of Zhengzhou University in 2016. BD Phenix-100 was used to identify the strains and detect the minimum inhibitory concentrations (MICs). Homology analysis was performed using pulsed-field gel electrophoresis (PFGE). The modified Hodge test was used to detect the phenotypes of carbapenemase. PCR and gene sequencing were used to detect the types of carbapenem resistance genes. The transferability of plasmids was detected by conjugation test. The characteristics of plasmids were analyzed by genomic alignment method after whole genome sequencing. DNAMAN V9 software was used to compare the amino acid sequences of the replication initiation proteins. A phylogenetic tree was constructed with neighbor-joining method using MEGA7.0. Results:All of the four S. marcescens strains were resistant to carbapenem antibiotics. They were highly homologous according to PFGE. Hodge test results were all positive and the carbapenemase genotype was blaKPC-2. Conjugation test results were positive. The plasmid was a circular DNA of 42 742 bp in length. It had the similar skeleton of incX6 plasmid and the similar amino acid sequence of replication initiation protein. Moreover, it and incX6 plasmid were at the same node in the phylogenetic tree. The blaKPC-2 was located in the core of drug resistance, which was composed of insertion elements including Tn3 family transposons, recombinant enzyme genes, △ISKpn6 and ISKpn27. Conclusions:The plasmid was incX6-like. The blaKPC-2 gene was located in the transposon of △Tn6296. More attention should be paid to the bacteria carrying KPC-2 in incX plasmids.
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Objects: To clarify the risk factors of candidemia and to assess the clinical differences that may exist between infection with Candida parapsilosis and that with other Candida species in cancer patients. To statistically analyze the clinical characteristics of Candi-da albicans candidemia and C. parapsilosis candidemia and risk factors for their infections. We aimed at a timely intervention through this type of analysis to avoid susceptible factors and improve the prognosis of patients with candidemia. Methods: We retrospectively included 323 patients with candidemia in Affiliated Cancer Hospital of Zhengzhou University between March 2012 and February 2018 and analyzed the clinical characteristics of these patients to establish the risk factors of candidemia. We performed a comparative anal-ysis of the clinical characteristics of C. parapsilosis infections and non-parapsilosis Candida spp. infections and of C. albicans infections and non-albicans Candida spp. infections. In addition, drug sensitivity tests and analyses were performed with the common antifungal drugs used in Candida infections by a micro-broth dilution method. The statistical software SPSS version 22 was used for the analyses. Results: A total of 323 patients were enrolled and analyzed in this study. Of the isolates, 34.37% were C. albicans and 65.63% were non-albicans Candida spp. Multivariate regression analysis showed that the following factors were associated with the occurrence of C. parapsilosis candidemia: parenteral nutrition (P<0.001), neutropenia (P<0.001), history of receiving chemotherapy (P=0.002), and history of previous antifungal use (P<0.001). Parenteral nutrition was found to be an independent risk factor for C. albicans candi-demia (OR=0.183; 95%CI:0.098?0.340; P<0.001). Conclusions: C. parapsilosis was found to be the primary pathogen in cancer patients with candidemia. Total parenteral nutrition in the intensive care unit at diagnosis and abdominal surgery were independent risk factors of candidemia, and parenteral nutrition was an independent risk factor of C. parapsilosis candidemia. At present, C. parapsilosis is sur-passing C. albicans as the main pathogen of candidemia in cancer patients at our hospital. This study emphasizes the need to assess the possible risk factors for candidemia in cancer patients and aims at strengthening and developing a hospital-based control strategy to prevent the spread of candidemia.
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Objective To study plasmid-mediated transfer,plasmid replicon typing,and genetic environment of blaNDM-1 gene in Enterobacteraerogenes(E.aerogenes).Methods E.aerogenes HN-NDM0711 was used as the subject of this research,the transferable properties of plasmid were analyzed by conjugation testing,conjugant was performed stability testing,plasmid type was determined by PCR-based replicon typing (PBRT),downstream and upstream of blaNDM-1 were sequenced using chromosome walking method,genetic context was analyzed by BLASTN and BALSTP,as well as annotated using Vector NTI 11.5.1 software,sequence pipeline graph was made,the sequence was submitted to Genbank through software Banklt.Results The conjugation testing of E.aerogenes pHN-NDM0711 was positive,after positive conjugant was conducted 4-day passage,minimal inhibitory concentrations (MICs) of imipenem and meropenem to all the cloned strains didn't change,blaNDM-1 were all positive.The replicon type was IncA/C;blaNDM-1 gene was localized between ISAba14 and IS91,at upstream of the blaNDM-1,class 1 integron and Tn3 transposon were identified,class 1 integron contained a new mosaic structure of a drug-resistant resistance gene cassette.Conclusion E.aerogenes pHN-NDM071 1,bearing blaNDM-1 gene in IncA/C plasmid,derived from gene recombination under different antimicrobial selection pressure.Antimicrobial use in clinical,industrial and agricultural area should be strictly controlled,so as to reduce the emergence of such bacteria.
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Objective To reveal the pancreatic cancer cell drug resistance mechanism to provide a basis for clinical treatment by studying miR-26b targeting p53 for promoting the drug resistance of pancreatic cancer cell line PANC-1 .Methods (1) The over-expression and knockdown plasmid of p53 and the fluorescent reporter vector containing 3′Untranslated region(3′UTR) were constructed respectively .(2) The effect of p53 and miR-26b on the growth and proliferation of PANC-1 was investigated by methyl thiazolyl tetrazolium(MTT) in the presence of gemcitabine .(3) The target relationship between miR-26b and p53 was determined by bioinformatics ,real-time polymerase chain reaction(PCR) ,fluorescent reporter vector and Western blot experiment .(4) The effect of p53 on the growth of miR-26b was investigated by salvage experiments .Results (1) The MTT experiment confirmed that ,in the presence of gemcitabine ,over-expression of p53 could inhibit the proliferation of pancreatic cancer cell line PANC-1 ,and knock-down of p53 could promote the growth and proliferation of PANC-1;(2) the bioinformatics prediction showed that miR-26b targeted p53 ,real-time PCR ,Western blot and fluorescent reporter vector experiment confirmed that p 53 is the target gene of miR-26b , and miR-26b inhibits transcription and translation of p53 by targeting the 3′UTR of p53 gene;(3) the MTT experiment confirmed that in the presence of gemcitabine ,over-expression of miR-26b could promote the growth and proliferation of PANC-1 cells ,and enhanced its resistance to gemcitabine ;(4) the rescue experiment confirmed that the simultaneous over-expression of p53 rescued the drug resistance promoting effect of miR-26b on PANC-1 .Conclusion miR-26b inhibits the expression of p53 by targeting 3′UTR of the p53 gene and enhances the drug resistance of pancreatic cancer cell line PANC-1 to gemcitabine .
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Objective To investigate the clinical significance of heart fatty acid binding protein (H-FABP) and pregnancy associ-ated plasma protein A(PAPP-A) in acute coronary syndrome(ACS) .Methods A case-control study was conducted in 60 patients with ACS ,45 patients with stable angina pectoris (SAP) and50 patients without coronary heart diseases (control group) .All plasma samples were tested H-FABP and PAPP-A .Results Concentrations of H-FABP and PAPP-A were significantly different among the 3 groups(P<0 .01) .H-FABP and PAPP-A in ACS group were significant higher than those of SAP group and control group (P<0 .01) ,however there were no significant differences between SAP and control group (P>0 .05) .The sensitivity and specificity of H-FABP were 91 .7% and 78 .0% respectively analyzed by ROC curve .Similarly ,the sensitivity and specificity of PAPP-A were 48 .3% and 98 .0% respectively .The correlation of H-FABP and PAPP-A was high(r=0 .835 ,P<0 .01) according to the analysis by Pearson correlation analysis .Conclusion Concentrations of plasma H-FABP and PAPP-A had close relationship with ACS ,the sensitivity of H-FABP was much higher ,both of which could be the potential biomarkers and contributed to the diagnosis of exist-ence and progress of ACS .
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Objective To investigate the clinical significance of heart fatty acid binding protein (H-FABP) and pregnancy associ-ated plasma protein A(PAPP-A) in acute coronary syndrome(ACS) .Methods A case-control study was conducted in 60 patients with ACS ,45 patients with stable angina pectoris (SAP) and50 patients without coronary heart diseases (control group) .All plasma samples were tested H-FABP and PAPP-A .Results Concentrations of H-FABP and PAPP-A were significantly different among the 3 groups(P<0 .01) .H-FABP and PAPP-A in ACS group were significant higher than those of SAP group and control group (P<0 .01) ,however there were no significant differences between SAP and control group (P>0 .05) .The sensitivity and specificity of H-FABP were 91 .7% and 78 .0% respectively analyzed by ROC curve .Similarly ,the sensitivity and specificity of PAPP-A were 48 .3% and 98 .0% respectively .The correlation of H-FABP and PAPP-A was high(r=0 .835 ,P<0 .01) according to the analysis by Pearson correlation analysis .Conclusion Concentrations of plasma H-FABP and PAPP-A had close relationship with ACS ,the sensitivity of H-FABP was much higher ,both of which could be the potential biomarkers and contributed to the diagnosis of exist-ence and progress of ACS .