ABSTRACT
Objective:Evaluate the application of Fourier transform infrared spectroscopy in the identification of homology of carbapenem-resistant Escherichia coli(CREC). Methods:A total of 26 carbapenem-resistant Escherichia coli strains were isolated from 9 provinces in China in 2018. The 900-1 200 cm -1 was selected as a spectral region for the Euclidean distance calculating and average linkage clustering between all isolates.The single nucleotide polymorphism (SNP) was analyzed by whole genome sequencing (WGS). Results:Twenty-six CREC strains were divided into 14 infrared spectros copy(IR) types by FTIR. The same IR type belonged to the same sequence type type.Compared with cluster analysis based on WGS, the consistency of FTIR cluster analysis was 92.3% (24/26).Conclusions:FTIR presented excellent performance in identification of homology of CREC.Besides, with the advantages of simple operation and rapid acquisition of results, FTIR may be a useful tool in clinical labs.
ABSTRACT
Objective@#To evaluate the ability of matrix-assisted laser desorption/ionization time-of-flight mass spectrometry (MALDI-TOF MS) in identifying the rmpA2-carrying hypervirulentKlebsiella pneumoniae.@*Methods@#A total of 57nonduplicateKlebsiella pneumoniae isolates were collected from the Second Affiliated Hospital of Zhejiang University and Henan Provincial People′s Hospital. Virulence gene rmpA2 and capsule K serotype-specific genes were detected by PCR, multilocus sequence typing (MLST) was performed for molecular typing, and string test was conducted to identify the hypermucoviscous phenotype. The ClinProTools software was used for peak analysis. Four standard algorithms, including support vector machine (SVM), genetic algorithm (GA), supervised neural network (SNN), and quick classifier (QC), were tested for their power to differentiate between rmpA2-positive and rmpA2-negative strains.@*Results@#Among the 57 Klebsiella pneumoniae isolates, 28 isolates belonged to sequence type (ST) 11 and carried the virulence gene rmpA2, of which 5 isolates were positive for string test; while the other 29 isolates were not detected rmpA2, and MLST divided them into five STs including ST11 (n=23), ST15 (n=3), ST1 (n=1), ST76 (n=1), and ST473 (n=1). The results of four standard algorithms were similar, while the sensitivity and specificity of SVM was the highest at 93.23% and 100% respectively. Analysis results of ClinProTools software suggested that the specific peaks for differentiating the rmpA2-positive and rmpA2-negative strains were 7 168.9 and 7 280.76, however, the peak intensity of themwere variant.@*Conclusion@#The sensitivity and specificity ofMALDI-TOF MS for rapid identification of rmpA2-carrying hypervirulentKlebsiella pneumoniae werehigher than 90% and there was a difference on the peak intensity of two specific peaks, which needs further study.(Chin J Lab Med, 2018, 41: 571-675)
ABSTRACT
Objective To evaluate the feasibility of using neutrophil bactericidal activity assay for analyzing the anti-bactericidal ability of hypervirulent Klebsiella pneumoniae ( hvKP) strains that harbored the virulence genes of rmpA and rmpA2 and were positive for string test .Methods A total of 150 non-duplicate blood-borne Klebsiella pneumoniae strains were collected from Zhejiang Province from January 2016 to July 2017.PCR was performed to detect carbapenem resistance genes (blaKPC, blaNDM, blaIMP-1, blaIMP-2), cap-sule genotypes (K1, K2, K5, K20, K54 and K57) and virulence genes (rmpA, rmpA2, iucA and iroN). Klebsiella pneumoniae strains that were positive for string test and harbored rmpA and rmpA2 genes were iden-tified as hvKP strains, while classic Klebsiella pneumoniae (cKP) strains were negative for string test, rmpA or rmpA2 gene.Neutrophil bactericidal activity assay was performed to analyze the virulence of Klebsiella pneumoniae strains and the survival rate was determined by using the following equation: the number of colony-forming units ( CFUs) in experimental group divided by the number of CFUs in control group .Re-sults Of the 150 Klebsiella pneumoniae strains, 43.3％ (65/150) harbored the rmpA2 gene and among them, strains positive for genes of rmpA, iroN and blaKPC and K2 respectively accounted for 73.8％, 80.0％, 75.4％and 40.0％.Twenty-four (36.9％) rmpA2 gene-positive strains showed positive result of string test.The survival rates of hvKP and cKP groups were respectively 0.866±0.056 and 0.368±0.058 and the difference between them was statistically significant (P<0.001).Conclusion Most of the hvKP strains that carry rmpA and rmpA2 genes and are positive for string test in Zhejiang Province survive the neu-trophil treatment , which indicates that the neutrophil bactericidal activity assay is an effective and simple method for identifying the virulence of Klebsiella pneumoniae.
ABSTRACT
Objective To explore the curative effectiveness of transplantation of bone marrow-derived liver stem cells (BDLSCs) transfected with rat interleukin-10 (IL-10) gene in the treatment of liver fibrosis in rats. Methods β2m-/Thy-1+BDLSCs isolated from Wistar rats were transfected with adenovirus-mediated rat IL-10 gene Wistar rats were subcutaneously injected with CCl4 to induce liver fibrosis, and randomly divided into three groups as follows: (1) the model group, infused with 1 ml normal saline (NS); (2) the BDLSC group, infused with NS containing untreated β2m-/Thy-1+BDLSCs (2×105 cells); (3) the IL-10 group, infused with NS containing β2m-/Thy-1+ BDLSCs transfected with IL-10 gene (2×105 cells). Infusion was done via the portal vein. Rats subcutaneously injected with olive oil served as control (the normal group). The BDLCs labeled with diamidine phenylindole dihydrochloride (DAPI) in the liver were localized. Pathological changes and collagen area in liver tissues were observed. Liver function and blood blotting function were tested. Results β2m-/Thy-1+ BDLSCs labeled with DAPI were observed in liver tissues of rats. Significant pathological changes of liver tissues were observed in the model group. Compared with the model group, pathological changes were alleviated to some extent in the BDLSC group. The morphology of liver tissue in the IL-10 group was mostly close to that in the normal group. Collagen deposition of liver tissues was increased obviously in the model group. However, transplantations of untreated and IL-10-transfected BDLSCs both reduced collagen area. Compared with the BDLSC group, collagen deposition was significantly suppressed in the IL-10 group. Transplantation of IL-10-transfected BDLSCs suppressed obviously the levels of ALT, AST, ALP, TBIL, PT and APTT as compared with the model group (P<0. 05). The levels of ALT, TBIL, PT and APTT in the IL-10 group were significantly reduced to the normal levels as compared with those in the BDLSC group (P<0. 05).Conclusions Transplantation of BDLSCs transfected with rat IL-10 gene was effective in treating liver fibrosis in rats. This combined strategy of IL-10 gene and BDLSCs may represent a feasible, effective and safe therapy form for liver fibrosis.
ABSTRACT
Objective To assess the regulating effects of interleukin-1? (IL-1?) on gene expression of Bax mRNA in human hyaline chondrocyte.Methods Hyaline chondrocytes of human were harvested enzymatically and cultured in DMEM supplemented with 20% bovine serum.In the experiment,various concentrations of IL-1? were added to the medium.The effects of IL-1? on the Bax mRNA were assessed by reverse transcriptase polymerase chain reaction (RT-PCR) in the passaged monolayer cell cultures of hyaline chondrocyte.Results IL-1? increased the Bax mRNA level in passaged cultures of hyaline chondrocyte.The difference was significant (P
ABSTRACT
AIM: To investigate the changes of bcl-2, bax expression and neuron apoptosis of cerebral cortex in lymphostatic encephalopathy of rats. METHODS: The model of lymphostatic encephalopathy was established by occluding and removing both the shallow and deep cervical lymph nodes in rats. The animals were sacrificed at 1, 2, 3, 5, 7 and 14 days after operation. HE staining was used to observe the structure of brain tissues and TUNEL staining was used to detect in situ cell apoptosis. The expressions of bcl-2 and bax were examined by RT-PCR. RESULTS: Cerebroedema appeared at the second day and was the most serious at the 5th day after blockage of cervical lymphatics. The number of TUNEL positive cells and the expression of bax began to increase at the 2nd day, reached a peak at the 5th day and dropped to control level at the 14th day. The expression of bcl-2 began to increase at the 1st day, reached a peak at the 5th day and dropped to control level at the 7th day. The increasing extent of bax was higher than that of bcl-2. CONCLUSION: The blockage of cervical lymphatics can lead to lymp[JP2]hostatic encephalopathy. Apoptosis is the main form of neuron death in the cortex and has relation to the increasing expression of bcl-2 and bax. [JP]