R Factors

R 系数
  • 文章类型: Journal Article
    医疗保健环境中耐碳青霉烯细菌的增加速率是一个需要紧急关注的问题。这种抗性是由金属-β-内酰胺酶(MBL)驱动的,它可以催化几乎所有临床上可用的β-内酰胺的水解,并且对所有临床上使用的β-内酰胺酶抑制剂具有抗性。在这项研究中,在机会病原体的多重耐药分离物中鉴定出一种未表征的MBL,吲哚金杆菌。序列分析预测该MBL(CIM-1)是具有非典型脂盒的脂蛋白。CIM-1的表征表明它是一种具有广谱活性的高亲和力碳青霉烯酶,包括所有头孢菌素和碳青霉烯类。结果还表明,CIM-1可能是具有未表征的脂质盒的膜相关MBL。使用预测工具,我们还发现了更多潜在的脂化MBLs与非规范脂质盒,突出了进一步研究脂化MBLs的必要性.
    The increasing rate of carbapenem-resistant bacteria within healthcare environments is an issue of great concern that needs urgent attention. This resistance is driven by metallo-β-lactamases (MBLs), which can catalyse the hydrolysis of almost all clinically available β-lactams and are resistant to all the clinically utilized β-lactamase inhibitors. In this study, an uncharacterized MBL is identified in a multidrug resistant isolate of the opportunistic pathogen, Chryseobacterium indologenes. Sequence analysis predicts this MBL (CIM-1) to be a lipoprotein with an atypical lipobox. Characterization of CIM-1 reveals it to be a high-affinity carbapenemase with a broad spectrum of activity that includes all cephalosporins and carbapenems. Results also shown that CIM-1 is potentially a membrane-associated MBL with an uncharacterized lipobox. Using prediction tools, we also identify more potentially lipidated MBLs with non-canonical lipoboxes highlighting the necessity of further investigation of lipidated MBLs.
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  • 文章类型: Journal Article
    背景:有关不匹配修复系统(MMR)缺陷的可用数据相互矛盾,并且来自小型研究。我们的研究旨在评估局部晚期直肠癌(LARC)患者MMR状态的治疗意义。
    方法:我们回顾性收集了在意大利卡利亚里大学医院肿瘤科接受LARC治疗的318例患者的数据,IstitutoNazionaledeiTumoriMilan,还有AOUOspedaliRiunitiAncona.所有患者均接受新辅助放化疗。主要目标是主要TRG,次要目标是病理完全反应,无病生存期(DFS)和总生存期(OS)。
    结果:160名患者(148pMMR和12dMMR)被纳入探索队列,158名患者(146pMMR和12dMMR)被纳入验证队列。在探索性和验证性队列中,有42.6%和43.1%的pMMR患者出现了一个主要的TRG,分别;而在两个队列的dMMR患者中均未显示主要TRG。与dMMR相比,探索性和验证性队列在pMMR患者中显示出统计学上显着的较高mDFS:NR与14个月和NRvs.17个月,分别。
    结论:我们的结果表明dMMR与术前放化疗反应不良之间存在关联,它们代表了新新辅助治疗策略的假设产生数据。
    Available data on Mismatch Repair system (MMR) deficiency are conflicting and derived from small studies. Our study aimed to evaluate the therapeutic implications of MMR status in patients with locally advanced rectal cancer (LARC).
    We retrospectively collected data from 318 patients affected by LARC treated in Italy at the Medical Oncology Units of the University Hospital of Cagliari, Istituto Nazionale dei Tumori Milan, and AOU Ospedali Riuniti Ancona. All patients underwent neoadjuvant chemoradiotherapy. The primary objective was major TRG while secondary objectives were pathological complete response, disease-free survival (DFS) and overall survival (OS).
    One hundred sixty patients (148 pMMR and 12 dMMR) were included in the exploratory cohort and 158 (146 pMMR and 12 dMMR) were included in the validation cohort. A major TRG has been shown in 42.6% and 43.1% patients with pMMR in exploratory and validation cohort, respectively; while no major TRG have been shown in dMMR patients in both cohorts. Exploratory and validation cohorts showed a statistically significant higher mDFS in pMMR patients compared to dMMR: NR vs. 14 months and NR vs. 17 months, respectively.
    Our results indicated an association between dMMR and poor response to preoperative chemoradiotherapy and they represent a hypothesis-generating data for new neoadjuvant strategies.
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  • 文章类型: Journal Article
    探讨叶绿体与咖啡抗性因子的关系,命名为SH1至SH9,对42种咖啡基因型的全基因组DNA进行测序,整个叶绿体基因组从头组装。叶绿体系统发育单倍型网络聚集了每个物种的个体,而不是SH因子。然而,第一次,它允许阿拉伯咖啡作为自发杂种“HíbridodeTimor”的母本进行分子验证。还在阿拉伯C.arabica参考基因组上比对个体读数,以将SH因子与叶绿体代谢联系起来,并对选定的核编码叶绿体蛋白(132种蛋白)进行了计算机分析。核编码的硫氧还蛋白样膜蛋白HCF164能够区分有和没有SH9因子的个体,由于与染色体7c相关的特定DNA变体(来自C.canephora衍生的亚基因组)。在HCF164蛋白中不存在硫氧还蛋白结构域和氧化还原活性二硫化物中心,在SH9个体中观察到,提高了对氧化还原调节的潜在影响的可能性。第一次,通过鉴定叶绿体蛋白的特定DNA变体,可以根据SH谱区分个体.本研究引入了一种尚未探索的策略,用于鉴定与SH因子相关的蛋白质/基因和H.vastatrix效应子的候选靶标,从而为咖啡育种计划创造了新的视角。
    To explore the connection between chloroplast and coffee resistance factors, designated as SH1 to SH9, whole genomic DNA of 42 coffee genotypes was sequenced, and entire chloroplast genomes were de novo assembled. The chloroplast phylogenetic haplotype network clustered individuals per species instead of SH factors. However, for the first time, it allowed the molecular validation of Coffea arabica as the maternal parent of the spontaneous hybrid \"Híbrido de Timor\". Individual reads were also aligned on the C. arabica reference genome to relate SH factors with chloroplast metabolism, and an in-silico analysis of selected nuclear-encoded chloroplast proteins (132 proteins) was performed. The nuclear-encoded thioredoxin-like membrane protein HCF164 enabled the discrimination of individuals with and without the SH9 factor, due to specific DNA variants linked to chromosome 7c (from C. canephora-derived sub-genome). The absence of both the thioredoxin domain and redox-active disulphide center in the HCF164 protein, observed in SH9 individuals, raises the possibility of potential implications on redox regulation. For the first time, the identification of specific DNA variants of chloroplast proteins allows discriminating individuals according to the SH profile. This study introduces an unexplored strategy for identifying protein/genes associated with SH factors and candidate targets of H. vastatrix effectors, thereby creating new perspectives for coffee breeding programs.
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  • 文章类型: Journal Article
    β-内酰胺抗生素的开发和共同进化的β-内酰胺酶之间存在军备竞赛,通过破坏β-内酰胺环来提供抗性。我们观察到某些β-内酰胺酶倾向于聚集,在抗生素对其活性位点的选择性压力下,其在整个进化过程中持续存在。有趣的是,我们发现现有的β-内酰胺酶活性位点抑制剂可以作为分子伴侣,促进这些阻力因素的适当折叠。因此,我们已经创建了ept-Ins,旨在通过使β-内酰胺酶错误折叠成细胞内包涵体来利用β-内酰胺酶的结构弱点的合成肽。这种方法恢复了耐药临床分离株对多种β-内酰胺抗生素的敏感性,包括那些在医学实践中构成重大挑战的扩展频谱变体。我们的研究结果表明,抗性因子的靶向聚集可以提供一种识别有助于解决全球抗生素抗性危机的分子的策略。
    There is an arms race between beta-lactam antibiotics development and co-evolving beta-lactamases, which provide resistance by breaking down beta-lactam rings. We have observed that certain beta-lactamases tend to aggregate, which persists throughout their evolution under the selective pressure of antibiotics on their active sites. Interestingly, we find that existing beta-lactamase active site inhibitors can act as molecular chaperones, promoting the proper folding of these resistance factors. Therefore, we have created Pept-Ins, synthetic peptides designed to exploit the structural weaknesses of beta-lactamases by causing them to misfold into intracellular inclusion bodies. This approach restores sensitivity to a wide range of beta-lactam antibiotics in resistant clinical isolates, including those with Extended Spectrum variants that pose significant challenges in medical practice. Our findings suggest that targeted aggregation of resistance factors could offer a strategy for identifying molecules that aid in addressing the global antibiotic resistance crisis.
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  • 文章类型: Journal Article
    The aim of the study was to understand the genetic basis of resistance of five β-lactam resistant Vibrio anguillarum isolates obtained from the gut content of Atlantic mackerel (Scomber scomberus), using whole genome sequencing and to characterize a novel β-lactamase (VAN-1) from these isolates.
    Antibiotic sensitivity pattern was determined using Sensititre™ plates and whole genome sequencing was carried out using Illumina MiSeq-based sequencing. The blaVAN-1 gene was synthesized and expressed in Escherichia coli Top10 cells.
    Five isolates obtained (out of 73) from the gut content of Atlantic mackerel were identified as Vibrio anguillarum. Whole genome assemblies ranged from 3.894 to 3.906 million bases in length with an average of 50 contigs. A novel β-lactamase blaVAN-1, sharing 77.7% nucleotide identity with a known mobile β-lactamase from Vibrio species was detected. The blaVAN-1 gene in these isolates is flanked by a truncated IS5 family transposase on one end and a hypothetical protein and outer membrane protein followed by another IS5 family transposase on the other end, suggesting its potential for mobility. The blaVAN-1 gene was absent in V. anguillarum type strain (ATCC 14181) and V. anguillarum isolates from bivalves and sea water in Norway. VAN-1 conferred ampicillin resistance when expressed in E. coli, thus confirming the functionality of this gene.
    Our study highlights the importance of the marine environment as a reservoir of new antibiotic resistance genes. Our results suggest that migratory fish may transport novel antibiotic resistance determinants over long distances.
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  • 文章类型: Journal Article
    Ubiquilin-4(UBQLN4)是一种蛋白酶体穿梭因子,直接与泛素化蛋白结合,并将其货物传递到26S蛋白酶体进行降解。我们先前表明,上调的UBQLN4通过MRE11A的降解决定了DNA损伤反应(DDR)。然而,DNA水平的调控机制,控制UBQLN4mRNA水平的转录和转录后水平仍然未知。在这项研究中,我们筛选了32种实体瘤类型,并通过免疫组织化学分析验证了我们的发现.UBQLN4在mRNA和蛋白质水平上上调,在肝脏中观察到最显著的值,乳房,卵巢,肺,和食道癌。UBQLN4mRNA水平高的患者在32种癌症类型中的20种预后明显较差。DNA扩增被确定为在多种癌症中促进UBQLN4上调的主要机制,甚至在肿瘤发展的早期阶段。使用CRISPR屏幕数据集,UBQLN4在81.1%(860/1,060)的实体瘤衍生细胞系中被鉴定为肿瘤细胞活力的常见必需基因。UBQLN4mRNA水平较高的卵巢癌细胞系对铂类化疗耐药,而他们对聚(二磷酸腺苷-核糖)聚合酶抑制剂(PARPi)更敏感。我们的发现强调了UBQLN4作为一种重要的泛癌症治疗诊断因子和DDR相关耐药性的精确肿瘤学生物标志物的效用。
    Ubiquilin-4 (UBQLN4) is a proteasomal shuttle factor that directly binds to ubiquitylated proteins and delivers its cargo to the 26S proteasome for degradation. We previously showed that upregulated UBQLN4 determines the DNA damage response (DDR) through the degradation of MRE11A. However, the regulatory mechanism at DNA level, transcriptionally and post-transcriptional levels that control UBQLN4 mRNA levels remains unknown. In this study, we screened 32 solid tumor types and validated our findings by immunohistochemistry analysis. UBQLN4 is upregulated at both mRNA and protein levels and the most significant values were observed in liver, breast, ovarian, lung, and esophageal cancers. Patients with high UBQLN4 mRNA levels had significantly poor prognoses in 20 of 32 cancer types. DNA amplification was identified as the main mechanism promoting UBQLN4 upregulation in multiple cancers, even in the early phases of tumor development. Using CRISPR screen datasets, UBQLN4 was identified as a common essential gene for tumor cell viability in 81.1% (860/1,060) of the solid tumor derived cell lines. Ovarian cancer cell lines with high UBQLN4 mRNA levels were platinum-based chemotherapy resistant, while they were more sensitive to poly (adenosine diphosphate-ribose) polymerase inhibitors (PARPi). Our findings highlight the utilities of UBQLN4 as a significant pan-cancer theranostic factor and a precision oncology biomarker for DDR-related drug resistance.
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  • 文章类型: Journal Article
    抗菌素耐药性(AMR)通过降低抗生素治疗细菌感染的有效性而严重威胁公众健康。大气颗粒物(APM)是一种常见的环境危害,通过引起各种疾病和传播细菌致病机制,影响人类健康,其中病原菌和AMR是必不可少的部分。APM微生物群和抗性体的性质,连同他们的塑造因素和相互关系,需要进一步检查。为了解决这个问题,我们分析了从四个集群(华北和华南,内蒙古,和西藏)。对于APM的微生物组(P<0.001)和核心电阻组(P<0.001)均发现了显着的区域化,统计分析显示不同地区存在显著差异。主坐标分析(PCoA)和随附的ANOSIM分析表明,微生物组和核心抗性组遵循相同的区域子聚类层次结构模式。这个发现,结合APM微生物群和核心抗性对环境参数的响应分析,显示出相似的响应模式,以及APM微生物群和核心电阻体之间的Procrustes分析(M2=0.963,P<0.05),强烈建议APM微生物群与核心抗性相关。共现网络分析进一步揭示了APM微生物群与核心抗性体之间相互作用的关键类群和抗微生物抗性决定因素。因此,结论是APM微生物组和耐药组组成具有高度区域性,环境污染物和APM水平影响APM微生物群和抗性体,APMs中的微生物组和抗性组显著相关(P<0.05)。重要性与大气颗粒物(APM)相关的细菌可以长距离传播。这些细菌的很大一部分可能会威胁人类健康。APM携带的病原菌的抗微生物耐药性(AMR)阻止了感染的治愈。因此,APMs中的病原菌及其AMR越来越受到重视。文献表明,APM中细菌AMR和细菌发病机理存在知识空白,包括它们的分布模式,相互关系,以及影响其成分的因素。这项工作旨在通过研究从13个城市收集的APM样本来弥合这一知识差距。结果表明,细菌和抗生素耐药性决定因素都是高度区域性的,它们的组成模式是显著相关的,并受到同一组环境因素的影响。
    Antimicrobial resistance (AMR) seriously threatens public health by reducing antibiotic effectiveness in curing bacterial infections. Atmospheric particulate matter (APM) is a common environmental hazard that affects human health by causing various diseases and disseminating bacterial pathogenesis, of which pathogenic bacteria and AMR are essential parts. The properties of APM microbiomes and resistomes, along with their shaping factors and mutual relationships, need further examination. To address this, we analyzed APMs collected from 13 cities within four clusters (North and South China, Inner Mongolia, and Tibet). Significant regionalization was found for both the microbiomes (P < 0.001) and core resistomes (P < 0.001) for APMs, with statistical analyses showing significant differences in different regions. Principal coordinate analysis (PCoA) and accompanying ANOSIM analyses showed that microbiomes and core resistomes followed the same regional subclustering hierarchy patterns. This finding, together with response analysis of APM microbiomes and core resistomes to environmental parameters that showed similar response patterns, as well as Procrustes analysis (M2 = 0.963, P < 0.05) between APM microbiomes and core resistomes, strongly suggested that APM microbiomes and core resistomes are correlated. Co-occurrence network analysis further revealed key taxa and antimicrobial resistance determinants in the interactions between APM microbiomes and core resistomes. Thus, it was concluded that APM microbiome and resistome compositions were highly regional, that environmental pollutants and APM levels impacted APM microbiomes and resistomes, and that microbiomes and resistomes in APMs are significantly correlated (P < 0.05). IMPORTANCE Bacteria associated with atmospheric particulate matter (APMs) can transmit over long distances. A large portion of these bacteria can potentially threaten human health. The antimicrobial resistance (AMR) of pathogenic bacteria carried by APMs prevents curing from infections. Therefore, both the pathogenic bacteria in APMs and their AMR are receiving more attention. The literature suggests a knowledge gap that exists for bacterial AMR and bacterial pathogenesis in APMs, including their distribution patterns, mutual relationships, and factors influencing their compositions. This work aimed to bridge this knowledge gap by studying APM samples collected from 13 cities. The results demonstrated that both bacteria and antibiotic resistance determinants were highly regional and that their composition patterns were significantly correlated, and influenced by the same group of environmental factors. This study thus determined the relationship between the two important aspects of bacterial pathogenesis in APMs and represents significant progress in understanding bacterial pathogenesis in APMs.
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  • 文章类型: Journal Article
    由于抗生素耐药性通常与健身成本有关,细菌采用多层调节机制来确保抗性因子的表达仅限于抗生素攻击的时间。在枯草芽孢杆菌中,染色体编码的ABCFATP酶VmlR赋予对截短侧耳素的抗性,lincosamide和A型链谱蛋白翻译抑制剂。在这里,我们表明vmlR表达受翻译衰减和转录衰减机制的调节。在vmlR前导区的上游开放阅读框翻译过程中,抗生素诱导的核糖体停滞可防止形成抗终止子结构,导致形成防止内在终止的抗终止子结构。因此,在抗生素存在下的转录诱导vmlR表达。我们还表明,在vmlR前导序列中暂停NusG依赖性RNA聚合酶可防止在不存在抗生素的情况下泄漏表达。此外,我们证明,通过受损的蛋白质合成诱导VmlR表达不需要VmlR挽救翻译缺陷的能力,例如通过核糖体组装缺陷对VmlR的本构诱导。相反,诱导的特异性取决于抗生素在vmlR前导序列内的调节开放阅读框上阻止核糖体的能力。最后,我们证明了(p)ppGpp介导的信号参与抗生素诱导的VmlR表达。
    Since antibiotic resistance is often associated with a fitness cost, bacteria employ multi-layered regulatory mechanisms to ensure that expression of resistance factors is restricted to times of antibiotic challenge. In Bacillus subtilis, the chromosomally-encoded ABCF ATPase VmlR confers resistance to pleuromutilin, lincosamide and type A streptogramin translation inhibitors. Here we show that vmlR expression is regulated by translation attenuation and transcription attenuation mechanisms. Antibiotic-induced ribosome stalling during translation of an upstream open reading frame in the vmlR leader region prevents formation of an anti-antiterminator structure, leading to the formation of an antiterminator structure that prevents intrinsic termination. Thus, transcription in the presence of antibiotic induces vmlR expression. We also show that NusG-dependent RNA polymerase pausing in the vmlR leader prevents leaky expression in the absence of antibiotic. Furthermore, we demonstrate that induction of VmlR expression by compromised protein synthesis does not require the ability of VmlR to rescue the translational defect, as exemplified by constitutive induction of VmlR by ribosome assembly defects. Rather, the specificity of induction is determined by the antibiotic\'s ability to stall the ribosome on the regulatory open reading frame located within the vmlR leader. Finally, we demonstrate the involvement of (p)ppGpp-mediated signalling in antibiotic-induced VmlR expression.
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  • 文章类型: Journal Article
    尽管取得了令人印象深刻的进展,对于复发/难治性弥漫性大B细胞淋巴瘤(r/rDLBCL),相当一部分患者仍经历嵌合抗原受体(CAR)T细胞免疫治疗的原发性或继发性耐药.原发性耐药的机制涉及T细胞外在和内在功能障碍。在本研究中,我们对135例接受鼠CD19/CD22鸡尾酒CART疗法治疗的DLBCL患者进行了回顾性评估.基于四个标准(输注后转基因/CAR阳性T细胞水平的最大扩增[Cmax],通过CAR转基因水平在+3个月[Tlast]时转基因的初始持久性,CD19+B细胞水平[B细胞恢复],以及对CAR-T细胞疗法的初始反应),48例患者被纳入研究,并分为两组(T正常组[n=22]和T缺陷组[n=26])。根据单变量和多元回归分析,白细胞去除术前乳酸脱氢酶(LDH)水平较高(风险比(HR)=1.922;p=0.045)和CAR-T细胞输注后细胞因子释放综合征(CRS)分级较低(HR=0.150;p=0.026)是T细胞功能障碍的独立危险因素.此外,使用全外显子测序,我们发现,与T正常组相比,T缺陷组47个基因的种系变异显著富集(96%vs.41%;p<0.0001),这些基因由CAR结构基因组成(n=3),T细胞信号1至3个基因(n=13),T细胞免疫调节和检查点相关基因(n=9),细胞因子和趋化因子相关基因(n=13),和T细胞代谢相关基因(n=9)。杂合种系UNC13D突变具有最高的组间差异(26.9%vs.0%;p=0.008)。复合杂合CX3CR1I249/M280变体,根据ClinVar数据库,称为致病和危险因素,在T缺陷组(26个中的3个)中富集。总之,临床特征和T细胞免疫缺陷遗传特征可能有助于解释治疗原发性耐药的潜在机制,并为CAR-T细胞免疫治疗提供新的见解.
    Despite impressive progress, a significant portion of patients still experience primary or secondary resistance to chimeric antigen receptor (CAR) T-cell immunotherapy for relapsed/refractory diffuse large B-cell lymphoma (r/r DLBCL). The mechanism of primary resistance involves T-cell extrinsic and intrinsic dysfunction. In the present study, a total of 135 patients of DLBCL treated with murine CD19/CD22 cocktail CAR T-therapy were assessed retrospectively. Based on four criteria (maximal expansion of the transgene/CAR-positive T-cell levels post-infusion [Cmax], initial persistence of the transgene by the CAR transgene level at +3 months [Tlast], CD19+ B-cell levels [B-cell recovery], and the initial response to CAR T-cell therapy), 48 patients were included in the research and divided into two groups (a T-normal group [n=22] and a T-defect [n=26] group). According to univariate and multivariate regression analyses, higher lactate dehydrogenase (LDH) levels before leukapheresis (hazard ratio (HR) = 1.922; p = 0.045) and lower cytokine release syndrome (CRS) grade after CAR T-cell infusion (HR = 0.150; p = 0.026) were independent risk factors of T-cell dysfunction. Moreover, using whole-exon sequencing, we found that germline variants in 47 genes were significantly enriched in the T-defect group compared to the T-normal group (96% vs. 41%; p<0.0001), these genes consisted of CAR structure genes (n=3), T-cell signal 1 to signal 3 genes (n=13), T cell immune regulation- and checkpoint-related genes (n=9), cytokine- and chemokine-related genes (n=13), and T-cell metabolism-related genes (n=9). Heterozygous germline UNC13D mutations had the highest intergroup differences (26.9% vs. 0%; p=0.008). Compound heterozygous CX3CR1I249/M280 variants, referred to as pathogenic and risk factors according to the ClinVar database, were enriched in the T-defect group (3 of 26). In summary, the clinical characteristics and T-cell immunodeficiency genetic features may help explain the underlying mechanism of treatment primary resistance and provide novel insights into CAR T-cell immunotherapy.
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  • 文章类型: Journal Article
    泛菌属。是经常在环境中检测到的细菌,是节肢动物的共生体。它们偶尔会引起人类感染,最近出现了广谱β-内酰胺酶(ESBL)和产生碳青霉烯酶的菌株。在这项研究中,我们报告了编码粘菌素抗性基因mcr-9的泛菌菌株的分离和完整基因组序列。该菌株是从新生儿病理病房的早产新生儿中分离出来的。在临床检查中,生命体征正常,血培养阴性.直肠拭子筛选产生ESBL的肠杆菌,允许分离细菌,并且使用短读取测序和长读取测序获得完整的基因组。发现mcr-9基因在IncHI2超质粒上编码,这赋予了对六类抗生素的耐药性,包括β-内酰胺(ESBL)。尽管存在mcr-9,但分离株仍对粘菌素具有敏感性,这可以解释为基因组中缺乏相容的调节基因(qseBC)。常规临床程序检测不到耐药基因的存在,也就是说,表型测试。这表明病房中可能正在进行无声的传播。据我们所知,这是对MDRP.calida和Pantoeaspp的首次描述。编码任何移动粘菌素抗性基因。
    Pantoea spp. are bacteria that are often detected in the environment and as symbionts of arthropods. They sporadically cause infections in humans and recently extended spectrum beta-lactamases (ESBL)- and carbapenemase-producing strains have started to emerge. In this study, we report the isolation and the complete genome sequence of a strain of Pantoea calida encoding the colistin-resistance gene mcr-9. The strain was isolated from a preterm newborn in a neonatal pathology ward. On clinical examination, his vital signs were normal and blood culture was negative. Rectal swab screening for ESBL-producing Enterobacterales allowed to isolate the bacterium, and a complete genome was obtained using both short and long read sequencing. The mcr-9 gene was found to be encoded on a IncHI2 superplasmid, which confers resistance to six classes of antibiotics, including beta lactams (ESBL). Despite the presence of mcr-9, the isolate retains susceptibility to colistin, which could be explained by the absence of compatible regulatory genes (qseBC) from the genome. The presence of the resistance gene is undetectable with the routine clinical procedures, that is, phenotypic tests. This suggests that a silent spread might be ongoing in the ward. To our knowledge, this is the first description of an MDR P. calida and of a Pantoea spp. encoding any mobile colistin resistance gene.
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