Prevalence of carriage of extended-spectrum β-lactamase-producing enterobacteria and associated factors in a French hospital

ObjectivesOur aim was to evaluate the prevalence and associated factors for carriage of extended-spectrum β-lactamase-producing enterobacteria (ESBL-PE) in a healthcare facility.MethodsIn 2016 a serial cross-sectional survey of ESBL-PE carriage in a French university hospital was conducted. All patients present on the day of the survey were screened for ESBL-PE carriage. Demographic characteristics and risk factors for ESBL-PE carriage were collected.ResultsIn all, 146/844 patients (17%) were digestive carriers of ESBL-PE; of these, 96 (66%) had not previously been identified. Among patients carrying ESBL-PE, Escherichia coli (62%) and CTX-M type (94%) predominated. Greater age, recent travel abroad, receipt of antibiotic, and prolonged hospitalization were associated with ESBL-PE carriage.ConclusionGiven the high prevalence of ESBL-PE and the high proportion of unknown carriers, our results strongly suggest reinforcing standard precautions rather than contact precautions for controlling the spread of ESBL-PE.     

纤维蛋白原β启动子区单倍型对特发型下肢深静脉血栓的影响

目的 观察纤维蛋白原β(FGB)启动子区单倍型对特发型下肢深静脉血栓(IDVT)的影响.方法 IDVT组及健康对照组各120例.采用启动子区完整测序技术及聚合酶链反应-限制性片段长度多态性(PCR-RFLP)双重检测纤维蛋白原β链基因启动子区-1 420G/A、-993 C/T、-854G/A、-455 G/A、-249C/T和-148C/T单核苷酸多态性(SNP)及基因型,对上述SNP连锁不平衡分析并构建单倍型模型.结果-993 C/T与-455 G/A、-993 C/T与-148C/T、-455 G/A与-148C/T之间存在较强的连锁不平衡关系(r2分别为0.699、0.509和0.556);构建出8种单倍型模型:单倍型H3、H6在病例组中的频率高于对照组[比值比(OR)分别为32.085和1.896,P＜0.05];单倍型H1、H4、H5和H7在对照组中的频率高于病例组(OR值分别为0.025、0.119、0.644和0.383,P ＜0.05);其余单倍型(H2和H8)在两组之间差异无统计学意义(P＞0.05).结论 单倍型H3、H6可能是下肢深静脉血栓(DVT)的危险因素;单倍型H1、H4、H5和H7可能是DVT的保护因素.     

miR-155在骨肉瘤发生发展及肺转移进程中的作用及机制

目的 初步探究miR-155在骨肉瘤发生发展及其肺转移进程中的作用,并探讨其靶蛋白及相关机制。方法 通过数据库分析,结合临床组织与细胞样本的相关检测,对骨肉瘤及其肺转移进程中miR-155差异性进行对比分析;应用iTRAQ定量蛋白质组学技术,筛选骨肉瘤及其肺转移进程中miR-155的靶蛋白;在临床组织与细胞样本中,对筛选的miR-155靶蛋白进行验证。结果 miR-155在骨肉瘤组织和肺转移瘤组织中,较对照组均出现明显升高;与人正常成骨细胞相比,人骨肉瘤细胞系miR-155亦出现明显升高。利用iTRAQ实验得到3 714个蛋白,筛选出差异表达蛋白253个,其中上调144个,下调109个。经预测分析和实验验证C/EBP β是miR-155潜在的作用靶蛋白。结论 miR-155在骨肉瘤及其肺转移进程中出现显著升高,C/EBP β是其潜在的作用靶点。     

Genomic analyses of the Daphnia pulex peptidome

Genome mining has provided a valuable tool for peptide discovery in many species, yet no crustacean has undergone this analysis. Currently, the only crustacean with a sequenced genome is the cladoceran Daphnia pulex, a model organism in many fields of biology. Here, we have mined the D. pulex genome for peptide-encoding genes. For each gene identified, the encoded precursor protein was deduced, and its mature peptides predicted. Twenty-four peptide-encoding genes were identified, including ones predicted to produce members of the A-type allatostatin, B-type allatostatin, C-type allatostatin, allatotropin (ATR), bursicon α, bursicon β, calcitonin-like diuretic hormone, corazonin, crustacean cardioactive peptide, crustacean hyperglycemic hormone, ecdysis-triggering hormone, eclosion hormone (EH), insulin-like peptide (ILP), molt-inhibiting hormone, neuropeptide F, orcokinin (two genes), pigment-dispersing hormone, proctolin, red pigment concentrating hormone/adipokinetic hormone (RPCH/AKH), short neuropeptide F, SIFamide, sulfakinin, and tachykinin-related peptide (TRP) families/subfamilies. In total, 96 peptides were predicted from these genes. Our identification of isoforms of corazonin, EH, ILP, proctolin, RPCH/AKH, sulfakinin and TRP are the first for D. pulex, while our prediction of ATR from this species is the first from any crustacean. The number of peptides predicted in our study shows the power of genome mining for peptide discovery, and provides a model for future genomic analyses of the peptidomes of other crustaceans. In addition, the data presented in our study provide foundations for future molecular, biochemical, anatomical, and physiological investigation of peptidergic signaling in D. pulex and other cladoceran species.     

Pathogens resistant to antibacterial agents

Resistance to antimicrobial drugs is increasing at an alarming rate among both gram-positive and gram-negative bacteria. Traditionally, bacteria resistant to multiple antimicrobial agents have been restricted to the nosocomial environment. A disturbing trend has been the recent emergence and spread of resistant pathogens in nursing homes, in the community, and in the hospital. This article reviews the epidemiology, molecular mechanisms of resistance, and treatment options for pathogens resistant to antimicrobial drugs.     

Prevalence of extended-spectrum beta-lactamases in Proteus mirabilis in a Taiwanese university hospital, 1999 to 2005: identification of a novel CTX-M enzyme (CTX-M-66)

A total of 1574 nonduplicate Proteus mirabilis isolates collected at a Taiwanese hospital during 1999 to 2005 were analyzed for production of extended-spectrum beta-lactamases (ESBLs). Forty-four ESBL-producing isolates including 22 CTX-M-14, 18 CTX-M-3, 2 CTX-M-24, and 2 CTX-M-66 producers were detected, and the proportion of ESBL producers increased from 0.7% in 1999 to approximately 6% after 2002. CTX-M-66 is a novel variant of CTX-M ESBLs that differs from CTX-M-3 by a Ser to Asn change at amino acid position 23. Coresistances to aminoglycosides and ciprofloxacin were very common in the CTX-M-3 producers. The presence of ArmA-type or RmtB-type 16S rRNA methylase that confers high-level aminoglycoside resistance was detected in 12 CTX-M-3 producers and 4 CTX-M-14 producers. Twenty-four clones including an endemic CTX-M-14-producing clone were observed among the 44 ESBL producers by pulsed-field gel electrophoresis, suggesting that both horizontal transfer and clonal spread contributed to the increased prevalence of bla(CTX-M) in P. mirabilis.     

Visfatin Protects Rat Pancreatic β-cells against IFN-γ-Induced Apoptosis through AMPK and ERK1/2 Signaling Pathways

ObjectiveInterferon-γ (IFN-γ) plays an important role in apoptosis and was shown to increase the risk of diabetes.Visfatin, an adipokine, has anti-diabetic, anti-tumor, and regulating inflammatory properties. In this study we investigated the effect of visfatin on IFN-γ-induced apoptosis in rat pancreatic β-cells. MethodsThe RINm5F (rat insulinoma cell line) cells exposed to IFN-γ were treated with or without visfatin. The viability and apoptosis of the cells were assessed by using MTT and flow cytometry. The expressionsof mRNA and protein were detected by using real-time PCR and western blot analysis. ResultsThe exposure of RINm5F cells to IFN-γ for 48 h led to increased apoptosis percentage of the cells. Visfatin pretreatment significantly increased the cellviability and reduced the cell apoptosis induced by IFN-γ. IFN-γ-induced increase in expression of p53 mRNA and cytochrome c protein, decrease in mRNA and protein levels of anti-apoptotic protein Bcl-2 were attenuated by visfatin pretreatment. Visfatin alsoincreasedAMPK and ERK1/2phosphorylation and the anti-apoptotic action of visfatin was attenuated by the AMPK and ERK1/2 inhibitor. ConclusionThese results suggested that visfatin protected pancreatic islet cells against IFN-γ-induced apoptosis via mitochondria-dependent apoptotic pathway. The anti-apoptotic action of visfatin is mediated by activation of AMPK and ERK1/2 signaling molecules.     

钙激活中性蛋白酶-2对整合素β4水解的影响

目的:观察乳腺癌细胞系MCF7细胞中,钙激活中性蛋白酶2(calpain-2)对整合素(integrin)β4水解的影响。方法:利用"短发夹"RNA(shRNA)和微小RNA(mirRNA)技术结合的calpain-2基因沉默(gene silencing)慢病毒质粒(GIPZ lentiviral shRNAmir)转染乳腺癌细胞株MCF7,嘌呤霉素筛选稳定沉默calpain-2基因的细胞株,细胞株传4代,用荧光显微镜观察转染效率,用蛋白质印迹(Western blot)实验检测calpain-2基因沉默效率及integrinβ4水解的情况。结果:嘌呤霉素筛选、细胞传4代,荧光显微镜下观察显示转染和筛选后,EGFP表达阳性的MCF7细胞的比例分别达到(95.6±2.6)%(空shRNAmir载体)、(97.1±1.7)%(Calpain-2 shRNAmir1)和(97.7±0.2)%(Calpain-2 shRNAmir 2),差异无统计学意义(P>0.05);Western blot结果显示,基因沉默的MCF7细胞中calpain-2的表达被明显抑制,相对于空shRNAmir载体转染的MCF7细胞,差异有统计学意义(P<0.01),calpain-2的表达下调到21.5%(Calpain-2 shRNAmir 1)和18.8%(Calpain-2 shRNAmir 2),空shRNAmir载体转染的MCF7细胞中calpain-2的表达与未转染的MCF7细胞比较,差异无统计学意义(P>0.05);比较calpain-2基因沉默和空shRNAmir载体转染的MCF7细胞,发现integrinβ4均被水解,水解片段的分子量主要有200 k D、130和95 k D;calpain-2基因沉默后,calpain-2基因沉默MCF7细胞中200 k D的水解片段比空shRNAmir载体转染的MCF7细胞减少(P<0.01)。结论:在乳腺癌细胞MCF7中,calpain-2可能参与integrinβ4的200 k D片段的形成,从而参与调整integrinβ4的构象变化。     

Comparing α7 nicotinic acetylcholine receptor binding,amyloid‐β deposition,and mitochondria complex‐I function in living brain: A PET study in aged monkeys

This study was aimed to assess the correlations among α7 nicotinic acetylcholine receptor (α7‐nAChR) binding, amyloid‐β (Aβ) deposition, and mitochondrial complex I (MC‐I) activity in the brain of aged monkeys (Macaca mulatta). Positron emission tomography (PET) measurements with [¹¹C](R)‐MeQAA, [¹¹C]PIB, and [¹⁸F]BCPP‐EF were conducted in monkeys in a conscious condition. [¹¹C](R)‐MeQAA binding was analyzed by a simplified reference tissue model to calculate nondisplaceable binding potential (BP_ND), [¹¹C]PIB uptake was calculated by standard uptake value ratio (SUVR), and [¹⁸F]BCPP‐EF binding was determined by Logan graphical analysis to calculate total distribution volume (V_T) with arterial blood sampling. Higher brain uptake was determined in the thalamus, hippocampus, striatum, and cortical regions for [¹¹C](R)‐MeQAA, while being lower in the cerebellum. Significant age‐related reduction of [¹¹C](R)‐MeQAA binding to α7‐nAChR was determined only in the occipital cortex. The plot of Vt of [¹⁸F]BCPP‐EF against BP_ND of [¹¹C](R)‐MeQAA indicated a significant negative correlation in the hippocampus and cortical regions in aged animals. Plotting of SUVR of [¹¹C]PIB against BP_ND of [¹¹C](R)‐MeQAA showed a positive correlation. The in vivo binding of [¹¹C](R)‐MeQAA could reflect the upregulation of α7‐nAChR induced by neurodegenerative damage determined by Aβ deposition as well as impaired MC‐I activity in living brain. Synapse 69:475–483, 2015. © 2015 Wiley Periodicals, Inc.