Vibrio alginolyticus is a foodborne pathogen that poses considerable threats to human health and leads to substantial economic losses in the aquaculture industry. O and K antigen are bacterial surface structures with strong plasticity and environmental adaptability, making O antigen biosynthesis gene clusters (O-AGCs) and K antigen biosynthesis gene clusters (K-AGCs) good materials for studying bacterial genetic evolution. However, no studies have carried out in-depth analyses of the O and K antigen-related gene clusters of V. alginolyticus. In the present study, we conducted the first genome-based serogroup study of V. alginolyticus and performed a comprehensive analysis of the O- and K-AGCs. We elucidated their molecular evolutionary mechanism by comparing them at the whole gene cluster structural and molecular levels. There were 14 serotypes of O-AGCs between dgkA and gmhD and 48 serotypes of K-AGCs between gmhD and rjg among V. alginolyticus chromosomes. Serogroups O1, O4, and O11 were most prevalent in our sample set, accounting for approximately 60% of all V. alginolyticus strains. The K serogroups had more extensive diversity than the O serogroups. We further identified the K serogroup-specific gene, wzy, corresponding to the serogroup in a one-to-one parallel relationship. The variation in K antigen, distinguished by the unique sequence of the gene wzy, makes an essential contribution to the diagnostic investigations of V. alginolyticus. Our results represent the first insight into the O and K antigen diversity of V. alginolyticus and underline the importance of the structural versatility and functional adaptability of O- and K-AGCs.

Vibrio alginolyticus, an emergent species of Vibrio genus, exists in aquatic and marine environments. It has undergone genetic diversification, but its detailed genomic diversity is still unclear. Here, we performed a multi-dimensional comparative genomic analysis to explore the population phylogeny, virulence-related genes and potential drug resistance genes of 184 V. alginolyticus isolates. Although genetic diversity is complex, we analysed the population structure using three sub-datasets, including the subdivision for three lineages into sublineages and the distribution of strains in the marine ecological niche. Accessory genes, most of which reclassified V. alginolyticus genomes as different but with relatively close affinities, were nonuniformly distributed among these isolates. We demonstrated that the spread of some post-evolutionary isolates (mainly L3 strains isolated from Chinese territorial seas) was likely to be closely related to human activities, whereas other more ancestral strains (strains in the L1 and L2) tended to be locally endemic and formed clonal complex groups. In terms of pathogenicity, the potential virulence factors were mainly associated with toxin, adherence, motility, chemotaxis, and the type III secretion system (T3SS). We also found five types of antibacterial drug resistance genes. The prevalence of beta-lactam resistance genes was 100%, which indicated that there may be a potential risk of natural resistance to beta-lactam drugs. Our study reveals insights into genomic characteristics, evolution and potential virulence-associated gene profiles of V. alginolyticus.

目的 了解流感嗜血杆菌耐药率变化及多位点序列分型,进行同源性分析,减少医院感染和多重耐药菌株的发生.方法 收集解放军总医院第六医学中心 2015-2022 年临床分离的 108 株流感嗜血杆菌,使用K-B法进行药物敏感性试验;采用多位点序列分析进行序列分型(sequence typing,ST);采用MEGA 7.0 软件的Neighbor-Joining法和Phyloviz 8.0 软件的goeBURST算法构建系统发育树和最小生成树分析菌株同源性.结果 近几年流感嗜血杆菌对氨苄西林、复方新诺明耐药率＞60%;108 株菌中,5 株未能与数据库匹配,103 株菌有 20 种ST型别,主要为ST-487(58 株,占 53.70%)和ST-147(19 株,占 17.59%);系统发育树分为 2 组,除ST-834 和ST-12422 种型别分布在Ⅱ组外,其余型别在Ⅰ组;最小发育树提示 2 大分支ST-487 和ST-147 都与ST-103 有相关性.结论 院内分离的流感嗜血杆菌多数菌株存在亲缘进化关系;多重耐药的流感嗜血杆菌在我院不同科室相继检出,提示编码耐药基因的质粒在病区间传播.

We investigated activities of cefiderocol combination therapy against carbapenem-resistant Acinetobacter baumannii (CR-AB). A total of 123 clinical isolates of CR-AB, including 44 cefiderocol-resistant isolates were tested. Cefiderocol functioned synergistically with tigecycline in most cefiderocol-susceptible isolates (84.8%, 67/79), but not with colistin or meropenem by checkerboard method. Cefiderocol functioned synergistically with tigecycline, colistin, and meropenem in 90.9% (40/44), 47.7% (21/44), and 79.5% (35/44) cefiderocol-resistant isolates, respectively. The time-kill assay and the in vivo Galleria mellonella model confirmed these observations. In summary, cefiderocol combined with tigecycline showed synergistic effects against both cefiderocol-susceptible and -resistant CR-AB, suggesting a potentially valuable combination regimen.

Background Cefiderocol is a promising antimicrobial agent against carbapenem-resistant, Gram-negative bacteria, but susceptibility data from the Chinese mainland are lacking. The aim of the present study was to test the susceptibility of cefiderocol against carbapenem-resistant, Gram-negative bacteria collected from Beijing, China. Methods Carbapenem-resistant Klebsiella pneumoniae (CR-KP; n=105), carbapenem-resistant Acinetobacter baumannii (CR-AB; n=126), carbapenem-resistant Pseudomonas aeruginosa (CR-PA; n=74), and Stenotrophomonas maltophilia (SM; n=72) isolates were collected from inpatients at 4 tertiary hospitals in Beijing, China. Minimum inhibitory concentrations (MICs) for cefiderocol were determined using iron-depleted cation-adjusted Mueller Hinton broth (CAMHB), and for comparators using CAMHB, according to the recommended Clinical and Laboratory Standards Institute (CLSI) methodology. Carbapenemase and other β-lactamase gene profiles were determined using polymerase chain reaction (PCR). Results Cefiderocol inhibited 100% of CR-KP and CR-PA, and 98.6% of the SM isolates at the susceptibility breakpoint concentration of 4 mg/L. However, the susceptibility rate for cefiderocol against CR-AB was only 62.7%, with MIC90 values as high as 128 mg/L. Nearly all the cefiderocol-susceptible CR-AB isolates were found to be positive for blaOXA-23 and blaTEM, whereas all the cefiderocol-resistant CR-AB isolates were found to be positive for the blaPER genes, in addition to blaOXA-23 and blaTEM. Conclusions Cefiderocol showed potent in vitro activity against CR-KP, CR-PA, and SM isolates collected from Beijing, China. However, the resistance rate for cefiderocol against CR-AB was higher than that reported by other research centers, and the presence of blaPER might contribute to resistance in non-susceptible CR-AB isolates.

Background: Cefiderocol (CFDC) is a promising antimicrobial agent against multidrug resistant Gram-negative bacteria. However, CFDC resistance has emerged in carbapenem-resistant Acinetobacter baumannii (CR-AB) but the underlying mechanisms remain unclear.Methods: Whole-genome sequencing and transcriptome sequencing were performed on CFDC-non-susceptible and CFDC-susceptible isolates. Two different recombinant plasmids was electro-transformed into the E. coli BL21 strain to determine the impact of blaPER and the combined impact of blaPER-1 and blaOXA-23 on CFDC resistance.Results: Fifty-five CR-AB isolates with minimum inhibitory concentrations (MICs) ranged from 0.06 mg/L to >256 mg/L were sequenced, including 47 CFDC-non-susceptible and eight CFDC-susceptible isolates. Two CFDC-non-susceptible isolates belonged to ST104 whereas the remaining isolates belonged to ST2, and blaPER-1 was present only in CFDC-non-susceptible isolates. Amino acid substitutions were noted in penicillin-binding proteins (PBPs) in four CFDC-susceptible isolates, with slightly elevated MICs. The MICs of recombinant E. coli BL21 carrying the blaPER-1 gene increased 64-fold and recombinant E. coli BL21 carrying both the blaPER-1 and blaOXA-23 genes increased 8-fold but both remained within the susceptibility range. Transcriptome sequencing of 17 CFDC-non-susceptible isolates and eight CFDC-susceptible isolates revealed that transcriptional levels of various iron transport proteins, such as fiu, feoA, and feoB, and the energy transduction system, TonB-ExbB-ExbD, were relatively downregulated in CFDCnon-susceptible isolates. GO enrichment analysis revealed that the upregulated genes in CFDC-non-susceptible isolates were mainly associated with redox homeostasis and stress response. Besides, the expression levels of the blaOXA-23 and exbD genes were negatively correlated with the MICs.Conclusion: PER-1 production, iron transport system downregulation, and mutations in PBPs may synergistically impart high-level resistance to CFDC in CR-AB.

Abstract Space flight missions last for a long time so bacterial infection during missions is considered a potential risk for astronauts. Studies of bacterial antibiotic resistance under spaceflight and simulated microgravity (SMG) have shown lots of results. To better understand the antibiotic resistance of Klebsiella pneumoniae in the microgravity environment, an original K. pneumoniae original strain was cultured under SMG conditions combined with background antibiotic exposure (SMGA) as the experimental strain, while the control strain was cultured in a normal gravity environment without antibiotic exposure. At the beginning of the treatment, the growth curves of the experimental and control strains were drawn. After 20 cycles of incubation, the antibiotic susceptibility, genomic, transcriptomic, and proteomic tests were conducted on the experimental and control strains. After the treatment, the experimental and control strain was inoculated into shake flasks under normal gravity without antibiotic exposure as an eraser experiment. During and after 10 cycles of incubation in shake flasks, antibiotic susceptibility tests were repeatedly conducted. The results showed that SMG conditions still increased the growth rate of K. pneumoniae despite of the background antibiotic exposure. Sustained exposure to SMGA condition resulted in acquired antibiotic resistance, which persisted for a period even though the SMGA condition was removed. The mechanisms of acquired antibiotic resistance under SMGA condition might include the loss of porin OmpK35, overexpression of the efflux pump OqxAB and upregulation of the AcrAB-TolC multidrug efflux system.

背景 近年来,随着航运经济发展,长远航人员生理和心理健康备受关注.目的 了解长远航人员咽部菌群分布以及随航行时间变化的分布特征,为疾病预防及后续深入研究积累基础数据.方法 采集2017年9月-2018年1月30名长远航人员在印度洋海域执行任务期间的咽部拭子,人员年龄20～53岁,男性18名,女性12名.其中包括医疗保障人员8名、船员8名、机组人员8名和后勤保障人员6名.采集时间为航行前、航行中1个月、航行中3个月和航行中4个月,共120份样本.按照采集时间分组进行高通量测序,分析扩增子序列变异体(amplicon sequence variants,ASVs)得到样本物种组成和丰富度信息.结果 120份样本数据中,4份样本测序失败.116份样本在2018年5月测序得到的菌群主要有厚壁菌门、拟杆菌门、放线菌门、梭杆菌门、变形菌门、疣微菌门、蓝藻门和糖细菌门,属水平主要有普氏菌属、拟杆菌属、瘤胃球菌、奈瑟菌属、嗜血杆菌属、乳酸杆菌属和厌氧球菌属,各自丰度有明显变化;与航行前相比,航行中1个月咽部出现噬纤维菌纲、鞘氨醇杆菌纲、脱硫弧菌属等水源性微生物;航行中3个月放线菌属和棒杆菌属丰度最高;航行中4个月,厚壁菌门和双歧菌属增到最高,拟杆菌门降到最低,疣微菌门逐渐消失.结论 长航人员咽部菌群与正常人群基本一致,但新增蓝藻门.随着航行时间增加,人员咽部菌群的结构和多样性发生了变化,水源性微生物增加.

背景 脑脊液标本病原菌培养是颅内感染诊断的金标准,目前临床多采用血培养瓶对脑脊液标本进行培养,阳性报警后再经过传代培养方可进行菌种鉴定和药敏试验,其耗时长,不利于临床及时诊治,有必要改进方法提高报告时效.目的 探讨HB&L(人体生物体液)微生物培养系统快速培养脑脊液阳性标本后进行菌种鉴定和药敏试验的准确性和时效性.方法 收集2021年1月-2022年1月我中心血液培养仪报阳性的脑脊液样本37例,分别进行常规分离培养和HB&L快速培养,以激光解析电离飞行时间质谱仪(MALDI-TOF MS)进行鉴定,以VITEK-2 Compact细菌鉴定药敏仪进行药敏试验.以常规培养法为金标准,评价HB&L快速培养法鉴定结果的正确率和药敏结果的符合率,比较两种方法的周转时间.结果 共分离鉴定出37株菌株,其中11株凝固酶阴性葡萄球菌、1株金黄色葡萄球菌、1株粪肠球菌、2株纹带棒杆菌、1株蜡样芽孢杆菌、6株鲍曼不动杆菌、6株肺炎克雷伯菌、3株铜绿假单胞菌、2株大肠埃希菌、1株阴沟肠杆菌、1株嗜麦芽窄食单胞菌和2株真菌.HB&L快速培养法菌种鉴定正确率为100％.与常规法药敏试验结果比较,HB&L快速培养法鉴定革兰阴性菌时替加环素、阿米卡星和米诺环素药物符合率为94.44％,其他抗菌药物符合率为100％;革兰阳性菌,红霉素符合率为92.31％,其他抗菌药物符合率为100％;HB&L快速培养法标准总符合率为98.90％,一般错误为0.82％,严重错误为0,极严重错误为0.27％.HB&L快速培养法菌种鉴定和药敏试验的周转时间相比常规法分别缩短22.10 h和24.77 h,差异有统计学意义(P<0.001).结论 HB&L联合MALDI-TOFMS和VITEK-2Compact可用于脑脊液培养阳性样本进行快速鉴定和药敏试验,回报时间缩短24 h,为临床及时治疗提供依据.

目的 评价荧光染色法在真菌镜检中的应用价值.方法 收集216例临床标本,同时进行革兰染色镜检、荧光染色镜检和真菌培养,3种方法中任意一种为阳性认为该标本真菌检测阳性,并以此标准,计算3种方法的真菌检出率,革兰染色法和荧光染色法的灵敏度和阴性预测值的差异,对比革兰染色与荧光染色镜下特点.结果 216例临床标本,革兰染色法、荧光染色法和真菌培养法的真菌检出率分别为11.57％、37.50％ 和42.13％,革兰染色法和荧光染色法灵敏度分别是23.15％和75.00％,阴性预测值分别是56.54％和80.00％,革兰染色法与荧光染色法或真菌培养法比较差异均有统计学意义(P<0.05).荧光染色法与真菌培养法比较差异无统计学意义(P>0.05).荧光染色法比革兰染色法镜下真菌形态更清晰易辨.结论 荧光染色法是快捷、准确的真菌检测方法,值得临床推广应用.

目的 建立基质辅助激光解吸电离飞行时间质谱(MALDI-TOF MS)霉菌数据库,提高引起临床相关感染的各种霉菌的鉴定能力.方法 收集临床标本来源的霉菌266株,纯培养后进行霉菌18S rDN A扩增测序,获得菌种鉴定结果.选取210株霉菌用于数据库的构建,通过甲酸萃取法提取蛋白,应用M A LDI-T O F MS配套的FlexControl软件收集蛋白谱图,采用Biotyper软件构建评价数据库.其余56株霉菌用于数据库鉴定能力的验证,分别用商品化数据库、自建的MALDI-TOF MS数据库和扩展数据库进行菌种鉴定,应用 χ2检验比较数据库的鉴定率差异.结果 自建本地化MALDI-TOF MS霉菌鉴定数据库包含19个菌属,67个菌种,共计204株霉菌的质谱图.用于数据库验证的56株霉菌中,用商品化数据库鉴定正确18株,鉴定正确率为32.1％,用扩展数据库鉴定正确51株,鉴定正确率为91.1％,差异有统计学意义(P<0.05).结论 自建霉菌数据库提高了霉菌的鉴定能力,从而有助于临床霉菌感染的病原诊断和治疗.

目的 探讨围生期孕妇无乳链球菌(GBS)的临床感染情况及耐药性特征,为临床合理使用抗菌药物提供参考.方法 对2017年4月至2020年3月在该院产检的围生期孕妇6313例进行GBS检测,根据检测结果 分为GBS阳性组和GBS阴性组,比较2组孕妇的一般资料及妊娠结局,分析GBS对10种抗菌药物的耐药率.结果 6313例围生期孕妇中,GBS感染率为7.16％(452/6313);2组孕妇年龄,妊娠期糖尿病、妊娠期高黏稠血症、妊娠期阴道炎检出率比较,差异无统计学意义(P>0.05),2组双胎妊娠、不良孕史比较,差异有统计学意义(P<0.05);2组在早产、羊水污染、产后出血、剖宫产率方面比较,差异无统计学意义(P>0.05),2组胎儿窘迫、先兆流产、胎膜早破发生率比较,差异有统计学意义(P<0.05).分离出的452株GBS对利奈唑胺、青霉素、奎奴普丁/达福普汀、替加环素、万古霉素、替考拉宁、氨苄西林敏感率为100.00％,对克林霉素、左氧氟沙星、四环素的敏感率分别为28.98％、44.91％、67.92％.结论 围生期孕妇GBS感染易造成胎儿窘迫、先兆流产及胎膜早破等不良妊娠结局,临床上应加强围生期孕妇GBS感染的防控工作,目前青霉素仍是治疗GBS的首选药物.

目的 探讨HB&L微生物培养仪对尿路感染(UTI)的诊断价值.方法 收集2019年6-12月在该院就诊的疑似UTI的277例患者作为研究对象,采集患者尿液标本,分别采用尿培养及HB&L微生物培养仪判断患者UTI情况,采用质谱仪鉴定阳性患者菌种分布情况,分析HB&L微生物培养仪培养对UTI的诊断价值.结果 HB&L微生物培养仪培养时间与尿培养时间比较,差异有统计学意义(P<0.05);277例尿液标本中,尿培养阳性检出率(23.47％)与HB&L微生物培养仪阳性检出率(23.10％)比较,差异无统计学意义(χ2=0.010,P>0.05);以尿培养结果作为金标准,HB&L微生物培养仪的灵敏度、特异度、准确度、阳性预测值、阴性预测值分别为96.92％、99.53％、99.28％、98.44％、99.06％;单一菌感染55例,混合菌感染10例,采用HB&L微生物培养仪鉴定菌种检出率为90.67％,错误率为1.33％,未检出率为8.00％.结论 与尿培养比较,HB&L微生物培养仪能够有效缩短培养时间,且二者阳性检出率比较无差异,HB&L微生物培养仪鉴定菌种的检出率较高.

Objective:To evaluate the identification rate of separating gel or HB&L pretreatment methods of MALDI-TOF-MS, thereby to provide a new idea for the rapid and accurate identification of pathogens of bloodstream infections in daily clinic practice.Methods:A total of 149 alarmed positive blood culture samples of single bacterial infection by routine laboratory methods were collected between January to December 2020 from the Sixth Medical Center, Chinese PLA General Hospital. Samples were pretreated with the separation gel accelerating tube method or the HB&L microbial culture system, followed by direct MALDI-TOF MS bacterial identification, the identification rates of the two pretreatment methods were compared and results from the traditional method were used as the standard control.Results:Among the 149 positive blood culture samples, 47.0% (70/149) were gram-negative (G -) bacteria and 53.0% (79/149) were gram-positive (G +) bacteria. Identification rate of G -strain level was 78.6% (55/70) by serum separation gel coagulation tube method and 91.4% (64/70) by HB&L microbial culture system, the difference was statistically significant ( P=0.033). Identification rate of G +strain levels was 73.4% (58/79) by serum separation gel coagulation tube method and 87.3% (69/79) by HB&L microbial culture system, the difference was statistically significant ( P=0.028). For G -bacteria in the range of 3.000-2.300, the identification rate was 22.9% (16/70) by serum separation gel accelerating tube method and 38.6% (27/70) by the HB&L microbial culture system, the difference was statistically significant ( P=0.044). For G +bacteria in the range of 3.000-2.300, the identification rate was 19.0% (15/79) by serum separation gel accelerating tube method and 34.2% (27/79) by the HB&L microbial culture system, the difference was statistically significant ( P=0.031). Conclusion:The identification rate of HB&L microbial culture system is higher than that of serum separation gel coagulation tube method. Direct MALDI-TOF MS identification of pathogenic bacteria in positive blood culture samples after pretreatment is feasible in daily clinical practice.

目的 评价基质辅助激光解吸电离飞行时间质谱(matrix assisted laser desorption ionization time-of-flight mass spectrometry,MALDI-TOF MS)用于临床常见酵母样真菌鉴定的截断值,为酵母样真菌鉴定提供适宜的评分标准.方法 收集从临床各类标本中分离出的酵母样真菌494株,将纯培养菌株直接涂抹至靶板上,滴加甲酸和基质液后进行MALDI-TOF MS鉴定,记录鉴定分值;同时进行基于真菌18srDNA的测序验证,以测序为金标准,评价MALDI-TOF MS鉴定的准确性;应用SPSS软件绘制ROC曲线,得出MALDI-TOF MS截断值,应用 χ2检验比较本次研究得出的截断值与机器推荐截断值鉴定的正确率和错误率.结果 27个菌种,463株酵母菌质谱鉴定与测序结果一致,鉴定正确率为93.7％;截断值为1.6时ROC曲线下面积最大,对应的敏感度为0.86,特异性为0.88;经 χ2检验,与原截断值2.0相比,截断值1.6可将正确鉴定率提高至77.7％,差异有统计学意义(P<0.001).结论 根据前处理方法的不同计算酵母样真菌鉴定适宜的截断值,将有助于提高MALTI-TOF MS酵母样真菌的鉴定能力.

目的 探讨荧光染色法在真菌镜检中的应用价值.方法 收集350例不同来源的临床标本,直接涂片后分别进行革兰染色和荧光染色镜检,同时接种沙保罗培养基进行真菌培养鉴定,3种方法任意一种为阳性,则认为该标本为真菌检测阳性,并以此为标准来计算3种方法的检出率、灵敏度和阴性预测值,应用χ2检验评价3种方法的差异.结果 350例临床标本应用荧光染色法、革兰染色法和真菌培养鉴定法的检出率分别为53.4％、11.4％和43.4％,灵敏度分别为86.6％、18.5％和70.4％,阴性预测值分别为82.2％,43.2％和67.7％,各组数据比较,差异均有统计学意义(P<0.05).结论 荧光染色法在真菌检测中显示出一定的优势,值得推广应用.

Aims Salmonella enterica serovar Enteritidis ( S . Enteritidis) infection is one of the main causes of foodborne illness among individuals in the military. In this study, we aimed to investigate indicators associated with the diagnosis, severity and outcome of S . Enteritidis infection, and to analyze the antimicrobial susceptibility of the isolated S . Enteritidis strains. Methods Routine stool test, fecal occult blood tests (FOBTs), routine blood tests and blood biochemical analyses were completed in our clinical laboratory. The stool samples were inoculated on Salmonella Shigella (SS) agar plates, the single bacterial colony was identified with mass spectrometry (MS). The serum agglutination test was performed to identify the Salmonella serotype. Antimicrobial susceptibility testing was performed using the minimal inhibitory concentration (MIC) method with the VITEK 2 COMPACT analyzer. Results Recently, 6 patients from one company visited our department complaining of fever, watery stool, abdominal pain and so on. The patients’ white blood cell (WBC) counts (66.7%), neutrophil percentages (100%), C-reactive protein (CRP) levels (100%), prothrombin times (PTs, 100%) and serum D-dimer concentrations (83.3%) were higher or longer than normal, while serum iron (100%) and prealbumin (83.3%) were lower than normal when they were admitted. Stool cultures and serovar identification results indicated S . Enteritidis infection. The antimicrobial susceptibility results showed that the 6 isolated bacterial strains were sensitive to trimethoprim-sulfamethoxazole and levofloxacin, and resistant to ampicillin. All patients were administered levofloxacin accompanied by rifaximin and probiotics, and their symptoms and the abovementioned parameters were recovered. During the disease course, the prolonged PT, elevated D-dimer and decreased serum iron were positively correlated with severe symptoms and serum inflammatory indexes. Conclusion Prolonged PT, elevated D-dimer and hypoferremia were associated with the diagnosis, severity and outcome of S. Enteritidis infection, and a decreased prealbumin level was associated with the diagnosis of S . Enteritidis infection. In patients complaining of acute fever, watery stool and abdominal pain, PT, D-dimer，prealbumin and serum iron should be monitored to attain an early diagnosis and initiate appropriate treatment for S . Enteritidis infection.

目的 建立海洋细菌基质辅助激光解吸电离飞行时间质谱鉴定数据库,为海洋细菌引起各类感染的病原快速鉴定提供支持.方法 本中心课题组2006-2016年收集国内外6个海域158个采样点海洋细菌530株,分离培养后进行细菌16srDNA扩增测序,应用FlexControl软件收集蛋白谱图,Biotyper软件构建评价数据库.分别用仪器商品化数据库、自建数据库和扩展数据库进行菌种鉴定,比较各数据库的鉴定差异.结果 自建本地化海洋细菌鉴定数据库包含32个菌属,82个菌种,共计421株海洋细菌谱图.以16srDNA测序鉴定结果 为金标准,验证菌株用商品化数据库鉴定时正确80株,鉴定正确率80.8％,用扩展数据库鉴定时正确97株,鉴定正确率98.0％,差异有统计学意义(P<0.001).结论 自建海洋细菌鉴定数据库菌株的鉴定能力较商品化数据库更强,有助于海洋细菌引起相关感染的诊断和治疗.

目的 运用基质辅助激光解析电离飞行时间质谱(MALDI-TOF-MS)联合分离胶法快速鉴定血培养阳性标本,探讨快速鉴定法的符合率.方法 运用分离胶法提取阳性血培养瓶中富集的菌落,应用MALDI-TOF-MS对经前处理的血培养阳性标本进行直接鉴定,鉴定结果与传统的VITEK-2 Compact全自动细菌分析仪鉴定结果进行比较,若有不符,以16SrRNA序列分析结果作为金标准.结果 在实验的200株阳性血培养标本中,革兰阳性菌的鉴定符合率达79.5％;革兰阴性菌鉴定符合率达85.7％;真菌的鉴定符合率达20.0％.由此可见,革兰阴性菌的鉴定符合率高于革兰阳性菌,二者鉴定符合率均远高于真菌.两种及两种以上细菌混合感染的阳性标本直接鉴定还存在一定困难,其直接鉴定方式还需进一步探讨.应用两种鉴定方法得出不同结果的12株阳性标本,16SrRNA序列分析结果均与VITEK-2 Compact全自动细菌分析仪鉴定结果一致.结论 MALDI-TOF-MS联合分离胶促凝管直接检测血培养阳性标本,对血流感染中主要病原菌的鉴定符合率较高,且迅速简便,此方法可将细菌更快地鉴定到种属,使临床能够进行早期治疗,有效控制菌血症的病死率和院内感染.

Hand, foot, and mouth disease (HFMD) is a common infection for children younger than the age of five. HFMD is mainly induced by coxsackievirus A16 and enterovirus 71 (EV71). EV71-associated HFMD often has serious neurological disease complications. The purpose of this study was to reveal the mechanisms of action of EV71 on neurons. SH-SY5Y cells transfected or untransfected with EV71 were sequenced. After data preprocessing, differentially expressed genes (DEGs) were screened using the limma package in R, and clustering analysis was then performed using the ComplexHeatmap package in R. The DAVID tool was used for EDG enrichment analysis. Protein-protein interactions (PPIs) were predicted using the STRING database and PPI networks were then constructed using Cytoscape software. After pathways involved in the key PPI network nodes were enriched, pathway deviation scores were calculated. Clustering analysis was also conducted for these pathways. There were 978 DEGs in the transfected samples. Upregulated TNF was enriched in NF-kappa B signaling pathway. Among the top 20 nodes in the PPI network, CDK1, STAT3, CCND1, TNF, and MYC had the highest degrees. A total of 28 pathways were enriched for the top 20 nodes, including Epstein-Barr virus infection (p = 3.78E-06), proteoglycans in cancer (p = 4.96E-06), and melanoma (p = 1.99E-05). In addition, clustering analysis showed that these pathways could clearly differentiate the two groups of samples. EV71 may affect neurons by mediating CDK1, STAT3, CCND1, TNF, and MYC, indicating that these genes are promising targets for preventing the neuronal complications of HFMD.