An analysis on biovars and antimicrobial susceptibility of 78 Ureaplasma strains isolated from respiratory tract of hospitalized infants / 预防医学

Objective To learn the biovars,antimicmbial susceptibility in Ureaplasma species isolated from respiratory tracts of infants hospitalized in tertiary children's hospital,and to provide evidences and clinical basis for the prevention and treatment of Ureaplasma infection in infants.Methods Ureaplasma species cultivation,identification and antibiotic susceptibility testing were performed using Mycoplasma IST2.The primers according to the conservative MB-Ag gene were designed to identify Ureaplasma biovars.Erythmmcin resistant genes (ermA,ermB and ermC) and active effiux transporter genes (mefA/E,msrA/B and mreA) were amplified using PCRs.Results A total of 78 Ureaplasma positive cases,of them,48 Ureaplasma strains were isolated from premature neonates.Biovar 1 was present in 51 (65.38％) strains,and biovar 2 was present in 27 (34.62％) strains.There were no significant differences among sex,premature infant,age,gestational age,birth weight,length of stay (P ＞ 0.05).The drug resistance rates to ciprofloxacin and ofloxacin were 80.77％,and to tetracycline was 1.28％.All strains were sensitive to doxycycline,josamycin and pristinomycin.The drug resistance rates to the macrolide antibiotics (erythromycin,azithromycinand and clarithromycin) were ＜ 12％.There was no statistically significant difference among the drug resistance rates of different biovars and these antibiotics (P ＞ 0.05).Only the methylated enzyme gene (ermB) and the active efilux pump gene (msrA/B) were detected,and the detection rate was 39.74％ and 12.82％ respectively.The ermB gene mainly exists in biovar 2,and the detection rate is 55.56％ (P ＜ 0.05).The msrA/B was balanced distributed between biovar 1 and 2 (P ＞ 0.05).A total of 78 Ureaplasma strains were isolated from 24 cases of neonatal septicemia,30 cases of congenital infection pneumonia,9 cases of retinopathy of prematurity,9 cases of neonatal intracranial hemorrhage,and 15 cases of bronchopulmonmT dysplasia.Conclusion Biovar 1 is more prevalent in Ureaplasma species isolated from infant respiratory tract,and higher detection rate of Ureaplasma is found in the preterm infants.All Ureaplasma strains have high drug resistance to both ciprofloxacin and ofloxacin,but low drug resistance to the macrolide antibiotics (erythromycin,azithromycin and clarithromyc),that could be used as a first choice for the treatment of Ureaplasma infection.Erythromycin resistance gene ermB,mainly exists in biovar 2.

First Report in China on the Identification and Drug Sensitivity of Mycobacterium elephantis Isolated from the Milk of a Cow with Mastitis / 生物医学与环境科学（英文）

<p><b>OBJECTIVE</b>In this study, milk from a cow with mastitis was analyzed to determine the presence of mycobacterial infection. Milk quality and security problems pertaining to the safe consumption of dairy products were also discussed in this study.</p><p><b>METHODS</b>Milk was preprocessed with 4% NaOH. Then, mycobacteria were isolated from the milk sample on L-J medium. The isolate was identified using multiple loci Polymerase Chain Reaction (PCR) and multi-locus sequence analysis with 16S rRNA, sodA, hsp65, and ITS genes. The drug sensitivity of the isolate to 27 antibiotics was tested through alamar blue assay.</p><p><b>RESULTS</b>Smooth, moist, pale yellow colonies appeared on the L-J medium within a week after inoculation. Based on the results of multiple loci PCR analysis, the isolate was preliminarily identified as non-tuberculous mycobacteria. The 16S rRNA, SodA, hsp65, and ITS gene sequences of the isolate exhibited 99%, 99%, 99%, and 100% similarities, respectively, with those of the published reference strains of Mycobacterium elephantis (M. elephantis). The drug sensitivity results showed that the strain is resistant to isoniazid, p-aminosalicylic acid, and trimesulf but is sensitive to ofloxacin, rifampicin, amikacin, capreomycin, moxifloxacin, kanamycin, levofloxacin, cycloserine, ethambutol, streptomycin, tobramycin, rifabutin, ciprofloxacin, linezolid, cefoxitin, clarithromycin, and minocycline.</p><p><b>CONCLUSION</b>To the best of our knowledge, this study is initially to report the isolation of M. elephantis from the milk of a cow with mastitis in China.</p>

Marsdeniae tenacissimae extract (MTE) suppresses cell proliferation by attenuating VEGF/VEGFR2 interactions and promotes apoptosis through regulating PKC pathway in human umbilical vein endothelial cells / 中国天然药物

Marsdeniae tenacissimae extract (MTE), commonly known as Xiao-Ai-Ping in China, is a traditional Chinese herb medicine capable of inhibiting proliferation and metastasis and boosting apoptosis in various cancer cells. However, little is known about the contribution of MTE towards tumor angiogenesis and the underlying mechanism. The present study aimed to evaluate the effects of MTE on the proliferation and apoptosis of human umbilical vein endothelial cells (HUVECs) and the molecular mechanism. 3-(4,5-dimethylthiazol-2-yl)-5(3-carboxymethoxyphenyl)-2-(4-sulfopheny)-2H-tetrazolium, inner salt (MTS) and PI-stained flow cytometry assays revealed that MTE dose-dependently reduced the proliferation of HUVECs by arresting cell cycle at S phase (P < 0.05). Annexin V-FITC/PI-stained flow cytometry confirmed that MTE (160 μL·L) enhanced the apoptosis of HUVECs significantly (P < 0.001). Real-time quantitative RT-PCR and Western blot analyses showed an increase in Bax expression and a sharply decline in Bcl-2 expression; caspase-3 was activated simultaneously in a dose-dependent manner (P < 0.05). Further study observed the dose-dependent down-regulation of vascular endothelial growth factor (VEGF) receptor-2 (VEGFR-2), P2Y6 receptor (P2Y6R), and chemokine (C-C motif) ligand 2 (CCL-2), along with the activation of PKC Δ and up-regulation of p53 in a dose-dependent manner in MTE-treated selected cells (P < 0.05). Collectively, the results from the present study suggested that MTE suppressed the proliferation by attenuating CCL-2-mediated VEGF/VEGFR2 interactions and promoted the apoptosis through PKCΔ-induced p53-dependent mitochondrial pathway in HUVECs, supporting that MTE may be developed as a potent anti-cancer medicine.

Proteomic analysis of peripheral blood mononuclear cells to identify potential markers of fibrosis in chronic hepatitis B / 中华肝脏病杂志

<p><b>OBJECTIVE</b>To identify non-invasive biomarkers for diagnosis and/or prognosis of liver fibrosis in chronic hepatitis B (CHB).</p><p><b>METHODS</b>Peripheral blood samples were obtained from 48 patients with CHB, including 24 with mild fibrosis (stage 1, S1) and 24 with severe fibrosis (stage 4, S4), and subjected to Ficoll density gradient centrifugation in order to obtain enriched samples of peripheral blood mononuclear cells (PBMCs).The PBMC proteomes of the two groups were assessed by first separating the total proteins by two-dimensional gel electrophoresis (2DE) and then identifying the differentially expressed proteins by liquid chromatography combined with tandem mass spectrometry (LCMS/MS).</p><p><b>RESULTS</b>The enriched PBMC samples from the S1 group and the S4 group had similar amounts of platelets [(19.268+/- 6.413) * 109/L and(19.480+/- 6.538) * 109/L, respectively); however, for both, the platelet amounts were 5 to 15-fold lower than that of the normal reference (100-300 *109/L). There was no significant difference found between the platelet amounts in the S1 patients and healthy controls (P=0.930). Twelve differentially expressed proteins were identified through 2DE-LC-MS/MS, including proteins such as moesin and NADH dehydrogenase [ubiquinone] iron-sulfur protein 3 that are involved in various biological processes like cell movement, cell adhesion, kinase signaling and transcription.</p><p><b>CONCLUSION</b>s The 12 proteins with differential expression in S1 and S4 patients with CHB and liver fibrosis may represent markers related to development and/or progression of liver fibrosis.</p>