Performance of MALDI-ToF MS for species identification of Burkholderia cepacia complex clinical isolates

We evaluated the performance of matrix-assisted laser desorption ionization–time of flight (MALDI-ToF) for identification of Bcc species compared with that of recA sequencing. MALDI-ToF was able of identifying 100% of Bcc isolates at the genus level, but 23.1% of Bcc isolates tested were not correctly identified at the species level. The misidentification occurred most frequently with Burkholderia contaminans (100%) and B. cepacia (33.3%).     

常熟地区呼吸病房临床常见革兰阴性菌的分布及耐药性分析

目的分析常熟地区呼吸病房临床常见革兰阴性杆菌分布及耐药性。方法对常熟地区3家市级医院呼吸病房2010年6月至2012年5月分离的革兰阴性杆菌及其耐药性进行回顾性分析。结果分离率前5位分别是肺炎克雷伯菌(35.3%)、铜绿假单胞菌(22.1%)、鲍曼不动杆菌(17.7%)、阴沟肠杆菌(10.1%)和大肠埃希菌(7.6%)。肺炎克雷伯菌和大肠埃希菌超广谱β内酰胺酶阳性率分别为21.4%和58.3%。革兰阴性杆菌对亚胺培南、阿米卡星、哌拉西林/他唑巴坦耐药率较低。结论常熟地区呼吸病房革兰阴性杆菌耐药性较强,必须加强细菌耐药性监测,指导临床合理用药。     

16SrRNA甲基化酶基因在产ESBLs肠杆菌科细菌中的分布

目的了解临床分离的产超广谱β-内酰胺酶（ESBLs）的革兰阴性肠杆菌科细菌中16SrRNA甲基化酶基因的分布情况。方法对临床分离的70株革兰阴性肠杆菌科细菌用VITEK．32型全自动微生物分析系统进行细菌鉴定,用纸片扩散法检测ESBLs,并用聚合酶链反应（PCR）检测armA、rmtA、rmtB、rmtC、rmtD和npmA6种16SrRNA甲基化酶基因,对检测的阳性产物进行测序,并通过GenBank比对DNA序列。结果70株产ESBLs革兰阴性肠杆菌中,9株16SrRNA甲基化酶基因阳性,其中5株检出armA基因,4株检出rmtB基因,2株同时检出armA和rmtB基因,rmtA、rmtC、rmtD、npmA4种基因扩增均为阴性。结论不同地区医院16SrRNA甲基化酶基因的分布情况各不相同。     

Severe sepsis and Toll-like receptors

Severe sepsis dominates the mortality of non-cardiac intensive care units. The ingenious Toll-like receptor (TLR) system can recognise many infectious organisms through relatively few receptors to trigger pro-inflammatory and anti-inflammatory cytokine release. Further complexity arises from positive and negative signalling feedback loops. Severe sepsis may be a consequence of an inappropriately excessive response or inadequate endogenous negative feedback. Therapies targeting these pathways are currently being evaluated. Alternatively, in clinical scenarios such as compensatory anti-inflammatory response syndrome, chronic viral sepsis or inadequate vaccine function, TLR signalling may be inadequate. TLR agonists may augment the innate response and are being investigated.     

Oligosaccharide conjugates of Bordetella pertussis and bronchiseptica induce bactericidal antibodies, an addition to pertussis vaccine

Pertussis is a highly contagious respiratory disease that is especially dangerous for infants and children. Despite mass vaccination, reported pertussis cases have increased in the United States and other parts of the world, probably because of increased awareness, improved diagnostic means, and waning vaccine-induced immunity among adolescents and adults. Licensed vaccines do not kill the organism directly; the addition of a component inducing bactericidal antibodies would improve vaccine efficacy. We investigated Bordetella pertussis and Bordetella bronchiseptica LPS-derived core oligosaccharide (OS) protein conjugates for their immunogenicity in mice. B. pertussis and B. bronchiseptica core OS were bound to aminooxylated BSA via their terminal Kdo residues. The two conjugates induced similar anti-B. pertussis LPS IgG levels in mice. B. bronchiseptica was investigated because it is easier to grow than B. pertussis. Using B. bronchiseptica genetically modified strains deficient in the O-specific polysaccharide, we isolated fractions of core OS with one to five repeats of the terminal trisaccharide, having at the nonreducing end a GlcNAc or GalNAc, and bound them to BSA at different densities. The highest antibody levels in mice were elicited by conjugates containing an average of 8-17 OS chains per protein and with one repeat of the terminal trisaccharide. Conjugate-induced antisera were bactericidal against B. pertussis, and the titers correlated with ELISA-measured antibody levels (r = 0.74). Such conjugates are easy to prepare and standardize; added to a recombinant pertussis toxoid, they may induce antibacterial and antitoxin immunity.     

3种检测痰抗酸杆菌方法的比较研究

目的探讨噬菌体生物扩增法、夹层杯法和直接涂片法(简称直涂法)在检测痰抗酸杆菌中的应用价值。方法收集临床确诊的114例活动性肺结核患者的晨痰,同时进行噬菌体生物扩增法、夹层杯法和直涂法检测痰抗酸杆菌,统计分析3种方法的检出率。结果噬菌体生物扩增法、夹层杯法和直涂法对114例晨痰标本的阳性检出率分别为50.9%、28.9%、16.7%,3种方法检出率两两比较,经卡方检验差异均具有统计学意义(P<0.01)。结论噬菌体生物扩增法检测抗酸杆菌阳性率明显高于夹层杯法和直涂法,且所需设备简单,是一种具有推广价值的检测方法。     

产β-内酰胺酶革兰阴性杆菌的筛选和耐药性分析

目的以多重耐药革兰阴性菌为对象,检测β一内酰胺酶表型,了解其耐药特性和分布特点。方法采用纸片扩散初筛法、扩散确证法、头孢西丁三维试验、甘露聚糖结合凝集素（MBL）的协同试验进行确证;采用法国梅里埃API生化鉴定试条或经VITEK一2鉴定系统将细胞鉴定到种;药敏试验用琼脂纸片扩散（K—B）法,经wH0一NET5．0软件进行统计学分析,分析其耐药特性。结果多重耐药革兰阴性杆菌口一内酰胺酶总检出率为26．4％（80／302）,主要由产超广谱β-内酰胺酶（ESBLs）引起,占16．56％（50／302）;其次为ESBLs＋AmpC引起,占6．62％（zo／302）;ESBLs＋AmpC＋MOL引起,占1．66％（5／302）,单独由AmpC引起的仅占0．66％（2／302）,有3株未能定型占0．99％（3／30z）。多重耐药革兰阴性杆菌对临床常用抗生素的总体耐药率最低的为阿米卡星（18．99％）、其次为亚胺培南（20．0％）,头孢哌酮／舒巴坦（21．7％）、哌拉西林／他唑巴坦（21．89％）;最高的为氨苄西林（98．33％）,其次为氨苄西林／舒巴坦（83．33％）、头孢曲松（76．25％）、头孢西丁（63．64％）及头孢噻肟（60．50％）等,大部分细菌呈多重耐药性。结论产多种6-内酰胺酶的革兰阴性菌具有多重耐药。     

重症监护室常见革兰阴性杆菌分布及耐药性

目的了解某院重症监护室（ICU）常见革兰阴性（G-）杆菌的分布及其耐药情况。方法回顾性分析该院ICU病区2008-2010年分离的常见G-杆菌种类及其药敏试验结果。细菌鉴定和药敏试验,采用法国生物梅里埃公司（bio Merieux）VITEK 2全自动微生物分析仪进行。应用WHONET5.5软件对数据进行统计分析。结果1 551株G-杆菌标本来源以痰液为主（68.06%）;常见G-杆菌以鲍曼不动杆菌所占比率最大（25.40%,394株）,其次为肺炎克雷伯菌（21.66%,336株）、大肠埃希菌（16.76%,260株）和铜绿假单胞菌（15.86%,246株）等;产超广谱β 内酰胺酶（ESBLs）肺炎克雷伯菌和大肠埃希菌株数分别为198株（58.93%）和174株（66.92%）。常见G-杆菌敏感性较好的抗菌药物主要为哌拉西林/他唑巴坦（耐药率19.23%～31.73%）、亚胺培南（耐药率9.23%～37.40%）、头孢哌酮/舒巴坦（耐药率14.88%～32.23%）、阿米卡星（耐药率22.92%～27.66%）。结论ICU病区的常见G-杆菌多重耐药现象严重,临床应根据药敏试验结果合理使用抗菌药物,以减少耐药菌株的产生。     

PICU下呼吸道感染患儿非发酵革兰阴性杆菌耐药现状分析

目的了解儿童重症监护病房(PICU)下呼吸道感染患儿主要病原菌的分布及其耐药性,指导临床合理使用抗菌药物。方法收集2008年2月-2011年1月PICU住院患儿下呼吸道分泌物分离的病原菌,对其进行菌株鉴定和药物敏感试验。结果 PICU下呼吸道感染痰标本细菌中,非发酵革兰阴性杆菌678株,占67.3%;分离率居前5位的革兰阴性杆菌依次为:铜绿假单胞菌占31.4%、鲍氏不动杆菌占29.8%、肺炎克雷伯菌占11.3%、大肠埃希菌占10.8%、嗜麦芽寡养单胞菌占4.6%,以上菌株对常用抗菌药物均产生了严重的耐药性。结论 PICU下呼吸道感染以非发酵革兰阴性杆菌为主,且多为多药耐药菌,临床治疗应根据药敏结果使用抗菌药物。