铜绿假单胞菌重组Bb-OprF疫苗诱导小鼠细胞免疫应答的研究

目的研究铜绿假单胞菌重组双歧杆菌(rBb)-OprF疫苗免疫小鼠,PAO1株攻击后产生的细胞免疫应答。方法将rBb-OprF疫苗分别采用皮下注射、肌肉注射、鼻腔黏膜和口服灌胃4种途径免疫Balb/c小鼠,免疫后8周用5×106CFU的PAO1株攻击,攻击1周后杀鼠取脾,MTT法检测特异性脾淋巴细胞增殖,流式细胞术检测脾CD4+T和CD8+T细胞比率,用ELISA法检测脾细胞培养上清IFN-γ、IL-12、TNF-α和IL-10的水平。结果脾T淋巴细胞增殖明显;脾细胞CD4+和CD8+T细胞亚群显著增加;脾细胞培养上清IFN-γ、IL-12、TNF-α和IL-10的水平显著升高,其中IFN-γ最为显著。结论铜绿假单胞菌rBb-OprF疫苗可诱导小鼠产生混合型的Th1和Th2免疫应答。     

BPIFB1在铜绿假单胞菌引起的炎症反应中的调节作用

目的研究杀菌性/通透性增强蛋白折叠结构1(BPIFB1)在铜绿假单胞菌引起的炎症反应中的作用机制和调节途径。方法应用RNA干涉、特异性蛋白激酶抑制剂阻断法,通过ELISA、Western blot法测定BPIFB1与脂多糖(LPS)共同作用于RAW264.7细胞后膜表面CD14、TLR受体以及胞内相关信号转导通路分子表达水平的变化情况。结果 BPIFB1与LPS作用后RAW264.7细胞表面CD14、TLR4和MyD88的表达水平明显下降;当细胞中MyD88、TRAF6、NF-κB等蛋白分子的表达被各自特异性siRNA所阻断后,BPIFB1与LPS抑制细胞因子TNF-α过表达的能力也被显著抑制;当用BPIFB1与LPS处理过的细胞用相应蛋白激酶抑制剂作用后,细胞内相关通路蛋白p38、pERK1/2、Akt1磷酸化水平被明显抑制。结论 BPIFB1与LPS结合通过阻抑相关胞内细胞因子的表达,降低了铜绿假单胞菌所产生的细胞炎性反应程度。     

铜绿假单胞菌随机扩增多态性DNA指纹法基因分型研究

建立了铜绿假单胞菌（ＰＡ）随机扩增多态性ＤＮＡ（ＲＡＰＤ）指纹图基因分型方法，并应用于流行病学相关或不相关的７５个ＰＡ菌株的基因分型。分型率为１００％。３２株新生儿暴发感染菌株，可分成４个血清型和５个ＲＡＰＤ谱型，其中２５株属于同一谱型。在８例患者的垂直追踪菌株中，除有１例其第１和第３个分离株的血清型和ＲＡＰＤ谱型均相同，但与第２个分离株的血清型和ＲＡＰＤ谱型不同外，其余７例前后菌株的谱型相同。１３株散发菌株可分成３个血清型和１０个ＲＡＰＤ谱型；１２株流行病学无关菌株的ＲＡＰＤ谱型均不相同。本研究结果表明，ＲＡＰＤ指纹图基因分型法具有分型率高、分辨力强、比较快速简便等优点，并且不需要已知核酸序列，是在分子水平上对微生物感染的病原学、发病机理及流行病学研究的较理想的方法。     

铜绿假单胞菌外毒素A的抗原性及其与辅助细胞？…

目的 研究铜绿假单胞菌外毒素Ａ（ＰＥ）的某些抗原性及其与辅助细胞的关系。方法 用ＭＴＴ法观察ＰＥ在有无辅助细胞参与条件下对鼠脾淋巴细胞的刺激作用并用鼠细胞毒性Ｔ细胞株ＣＴＬＬ进行证实。结果 ＰＥ０．０１～１００ｎｇ／ｍｌ浓度范围能刺激鼠脾淋巴细胞增殖，ＰＥ的丝裂原作用无需粘附细胞的辅助，但粘附细胞及其粘附细胞的ＰＥ刺激上清能协同ＰＥ对鼠脾淋巴细胞的刺激作用。ＰＥ在丝裂原作用范围内能刺激ＣＴＬＬ细胞     

耐环丙沙星铜绿假单胞菌的耐药性分析

目的 了解本地区铜绿假单胞菌的耐药情况及超广谱β-内酰酶（ESBLS）的检出率，以指导临床合理用药。方法对90株临床分离菌用纸片扩散法（K-B法）进行药物敏感性试验；纸片扩散表型确证法进行ESBLS检侧。结果本地区铜绿假单胞菌对氨苄西林、萘啶酸、哌拉西林、头胞噻肟、头胞吡肟、阿米卡星、环丙沙星、左氧氟沙星、司帕沙星、加替沙星、氨曲南、头胞他啶、亚胺培南、头胞呋辛的耐药率分别是90．0％、83．3％、77．2％、29．4％、5％、8．9％、65．0％、60．0％、62．2％、50．0％、7．2％、18．3％、0、47．2％；ESBLS的检出率为24．4％。结论本地区铜绿假单胞菌耐药情况不容乐观且多重耐药菌株较多；氟喹诺酮药物之间交叉耐药明显；产ESBLS率较高。     

MyD88-铜绿假单胞菌表位核酸疫苗的构建及其真核表达

目的:构建重组MyD88基因的铜绿假单胞菌(PA)表位核酸疫苗,并研究其在真核细胞中的表达.方法:将PA的OprF的三个中和性B细胞表位及一个外源通用T细胞表位串联,表位之间用赖氨酸间隔,采用重叠PCR方法合成全基因,并在此序列前插入组织纤溶酶原激活物(tPA)的信号肽基因,将获得的片段与MyD88基因分别克隆到pIRES载体的两个多克隆位点,构建真核双表达重组质粒pIRES-tPA-OprF-MyD88.电穿孔法将pIRES-tPA-OprF-MyD88转入COS-7细胞,通过Western blot检测其细胞上清tPA-OprF蛋白及细胞内MyD88蛋白的表达.结果:构建的真核表达质粒pIRES-tPA-OprF-MyD88,经电转COS-7细胞后,在其培养的上清液及细胞内检测到目的蛋白.结论:成功构建pIRES-tPA-OprF-MyD88表达载体,并在转染的真核细胞中得以有效地表达,为研究PA预防性疫苗奠定了实验基础.     

铜绿假单胞菌的GM-PFGE分型的研究

目的研究全基因组ＤＮＡ稀有位点限制性内切酶酶切脉冲电场电泳图谱（ＧＭ－ＰＦＧＥ）在铜绿假单胞菌基因分型中的应用,并与表型分型比较。方法对１个月内来自两个医院的病人及环境的２０株铜绿假单胞菌进行了ＧＭ－ＰＦＧＥ图谱分析,同时进行３０种生化反应的统计分型、２３种药物的敏感性分型、胞外脂多糖的血清抗原分型;并利用数值分类软件包进行相关性比较研究。结果临床致病铜绿假单胞菌的生化表型基本稳定,但其药物抗性的获得与丢失较为明显。血清型、生化性状及药物抗性之间无明显对应关系。当２菌株ＧＭ－ＰＦＧＥ图谱条带相似系数大于８０％时,为同一菌株的不同克隆亚型,当相似系数在２５％～７０％之间时,则为不同菌株。结论ＧＭ－ＰＦＧＥ分析可显示染色体结构的区域多型性,其重复性好,分辨率明显高于表型分型,结果可靠,必将成为铜绿假单胞菌或其它病原微生物分子流行病学研究的有力工具。     

耐喹诺酮类铜绿假单胞菌的耐药机制研究

目的探讨广州地区铜绿假单胞菌对喹诺酮类药物的耐药机制。方法对喹诺酮耐药株的gyrA和parC基因进行限制性片段长度多态性分析（PCR-RFLP）,并对其中的高水平耐药株gyrB和parE基因进行测序;用琼脂稀释法测定加入碳酰氰基-对-氯苯腙（CCCP）前后环丙沙星的最小抑菌浓度（MIC）;同时用SDS-PAGE对高水平耐药株的外膜蛋白进行电泳分析。结果有72.7%（72/99）的菌株发生gyrA突变,主要为Thr-83-Ile;25.3%（25/99）的菌株发生parC突变,主要为Ser-87-Leu,且均是gyrA和parC双基因突变;gyrB和parE突变较少见。53.3%（53/99）的菌株的MIC可被CCCP逆转,其MIC能明显降低;7%（7/10）的高水平耐药株的外膜蛋白在43～67kDa间条带增多,其蛋白含量有差异。结论抗菌药物作用靶位的改变和外排泵机制是本地区铜绿假单胞菌对喹诺酮类耐药的重要机制。     

生物膜铜绿假单胞菌对小白鼠的致病作用

目前生物膜菌感染的治疗是临床亟待解决的课题 ,因此对生物膜菌的致病机理需要深入的研究 ,才能有效的治疗生物膜菌引起的感染。对 6周龄、雄性清洁级小鼠 ,分别用铜绿假单胞菌悬液和生物膜状态的铜绿假单胞菌在小鼠气管内接种 ,进行 3项试验 :①以细菌浓度为 5× 10 6ＣＦＵ ｍｌ接种 2 0 μｌ 只测定鼠肺泡灌洗液 (ＢＡＬＦ)中白细胞数 ,结果见表 1。 2种细菌接种后ＢＡＬＦ中的白细胞数差异有显著性 (Ｐ <0 .0 1)。②测定 2组感染小鼠的存活率每组 30只小鼠分别将 10 6ＣＦＵ ｍｌ的 2组菌液 2 0 μｌ 只接种到鼠气管内 ,观察 10ｄ小鼠存…     

三种检测铜绿假单胞菌AmpC酶方法的评价

目的探讨一种简便易行，适用于临床微生物实验室常规开展检测AmpCβ内酰胺酶（简称AmpC酶）的方法。方法对临床分离的150株铜绿假单胞菌用表型筛选试验作AmpC酶测定，对AmpC酶阳性菌株同时进行氯唑西林双纸片协同试验、氟氯西林（FCC）双抑制剂扩散协同试验、PCR基因检测。用基因检测来评价比较三种测定方法的检出率及差异。结果表型筛选试验AmpC酶阳性37株同时进行氯唑西林双纸片协同试验、氟氯西林双抑制剂扩散协同试验、基因检测，检测出阳性株分别为15、14、11株，阳性率分别是40．54％（15／37）、37．84％（14／37）、29．73％（11／37）。表型筛选试验与后三种方法比较差异有统计学意义（P〈0．01），后三种方法结果比较差异无统计学意义（P〉0．05）。结论氯唑西林双纸片协同试验、氟氯西林双抑制剂扩散协同试验检测AmpC酶特异性较表型筛选试验高，且操作简便、结果可靠，适合临床实验室常规检测应用。     

New classes of orthopoxvirus vaccine candidates by functionally screening a synthetic library for protective antigens

The licensed smallpox vaccine, comprised of infectious vaccinia, is no longer popular as it is associated with a variety of adverse events. Safer vaccines have been explored such as further attenuated viruses and component designs. However, these alternatives typically provide compromised breadth and strength of protection. We conducted a genome-level screening of cowpox, the ancestral poxvirus, in the broadly immune-presenting C57BL/6 mouse as an approach to discovering novel components with protective capacities. Cowpox coding sequences were synthetically built and directly assayed by genetic immunization for open-reading frames that protect against lethal pulmonary infection. Membrane and non-membrane antigens were identified that partially protect C57BL/6 mice against cowpox and vaccinia challenges without adjuvant or regimen optimization, whereas the 4-pox vaccine did not. New vaccines might be developed from productive combinations of these new and existing antigens to confer potent, broadly efficacious protection and be contraindicated for none.     

An outbreak of carbapenem-resistant Pseudomonas aeruginosa in a urology ward

Objective  To investigate an outbreak of carbapenem-resistant Pseudomonas aeruginosa (CRPA) in a urology ward.
Methods  Patients infected or colonized with CRPA were prospectively identified by daily laboratory surveillance. Routine infection-control measures were reinforced, disinfection protocols were revised, and a surveillance program was set up, analyzing cross-transmission in the nursing ward and environment cultures from urology wards and the operating theater. CRPA isolates from clinical and environment samples were studied by pulsed-field gel electrophoresis (PFGE), following Xba I and Spe I restriction.
Results  From February 1998 to September 2000, 59 adult urology patients were colonized or infected by CRPA. All patients had been operated on prior to identification of the CRPA isolate and 79% of these procedures were performed in the same cystoscopy room. No patients had received prior carbapenem therapy. No cross-transmission was detected, and environment cultures from the urology ward and theater were negative except for five samples collected in the cystoscopy room. PFGE identified a single clone in the isolates from different patients and the environment samples.
Conclusions  The PFGE analysis indicated that the CRPA outbreak resulted from the contamination of the cystoscopy room via an unsealed drain. The outbreak ended when the drain was sealed.     

铜绿假单胞菌噬菌体的分离鉴定及其控制生物被膜的应用研究

目的 分离鉴定铜绿假单胞菌烈性噬菌体,研究噬菌体控制宿主菌形成牛物被膜的效率.方法 以铜绿假单胞菌临床菌株为指示菌,从不同环境样品中分离噬菌体;采用限制性内切酶图谱分析和宿主范围测定方法,对分离的噬菌体进行分类;利用透射电子显微镜对分离噬菌体进行形态学研究;以TJC729为指示菌,开展噬菌体控制牛物被膜形成的应用研究.结果 分别以14株铜绿假单胞菌临床分离菌株为指示菌,共分离得到13株烈性噬菌体,命名为C1～C13.利用限制性内切酶EcoR Ⅰ分析结果表明,13株噬菌体基因组均为双链DNA,并可被分成8组;宿主谱测定结果显示,c1和C13、C6和C7、C9和C11分别具有相同的宿主范围,其余7株噬菌体的宿主范围各不相同.随机挑选噬菌体C1进行形态学研究,发现噬菌体C1头部具有二十面体结构,尾部较长且无收缩性尾鞘,属于长尾噬菌体科.生物被膜控制实验结果显示,混合噬菌体能够较好地抑制TJC729生物被膜的形成.进一步实验结果显示,噬菌体C1、C10和C12分别与牛物被膜混合培养24 h后,牛物被膜的量分别下降到初始量的32.7%、57.6%、32.8%.结论 分离了13株铜绿假单胞菌烈性噬菌体,它们能够显著抑制宿主菌生物被膜的形成,并对生物被膜造成一定程度的破坏,为控制铜绿假单胞菌引起的感染提供了一个新方法.

Abstract：

Objective To isolate and classigy the bacteriophages specific to Pseudomonas aetuginosa and to investigate biofilm control efficaey of the isolated virulent phages.Methods With P. aeruginosa clinical strains as indicators.bacteriophages were isolated by screening difierent environmental samples.Classification of the isolated phages was done with the methods of restriction fragment analysis of phage genome and host range analysis.Transmission electron microscopy(TEM)was used in phage morphology study.In biogilm control tests,TJC729 was used as the jndicator strain to study the biofilm control efficacy of the isolated phages.Results Total 13 lytic phages specific to P.aeruginosa strains were isolated and named as C1-C13.According to the result of restriction fragment analysis.all 13 phages were double-stranded DNA viruses and could be divided into eight groups.Host range experiments were conducted with 5 laboratory strains and 12 clinical strains of P. aeruginosa.The same infection profiles were observed among phage C1 and C13,C6 and C7,and C9 and C11,respectively.While the remaining 7 phages each had different unique infection profile.Phage C1 was selected randomly to study its morphology.The obtained images showed that phage C1 had an icosahedral head with a non-contractile tail,belonging to the Siphoviridae family.Compared with the single phage,phage cocktail had the best effect on biofilm control.Further experiment results showed that phage C1.C10 and C12 can destroy biofilm after treatment of the biofilm for 24 h.The biofilm amounts were deceased to 32.7%,57.6%and 32.8%of the initial values,respectively.Conclusion Thirteen virulent phages specific to P. aeruginosa had been isolated.The phages could significantly inhibit the biofilm formation and had a certain degree of damage on the biofilm.The results suggested an alternative method for the treatments of P.aeruginosa infections.     

Cellular immunity in healthy volunteers treated with an octavalent conjugate Pseudomonas aeruginosa vaccine

Humoral immunity in response to an octavalent O-polysaccharide-toxin A conjugate Pseudomonas aeruginosa vaccine is well studied, and a Phase III clinical study in cystic fibrosis (CF) patients is currently ongoing. In contrast, little is known about cellular immunity induced by this vaccine. Fifteen healthy volunteers were immunized on days 1 and 60. Parameters of cellular immunity were studied before vaccination on day 1, and on day 74. Analyses included flow cytometry of whole blood, and antigen-induced proliferation of and cytokine production by lymphocyte cultures. The effects of immunization on the composition of peripheral blood lymphocytes as determined by flow cytometry were minor. In contrast, after immunization a highly significant increase of proliferation in response to stimulation with detoxified toxin A was noted: the stimulation index rose from 1.4 on day 1 to 42.2 on day 74 (restimulation with 0.4 microg/ml; P = 0.003). Immunization led to significant production of interferon (IFN)-gamma and tumour necrosis factor (TNF)-alpha by antigen-stimulated lymphocytes. In contrast, no significant induction of interleukin (IL)-4 or IL-10 was observed. In conclusion, immunization of healthy volunteers led to activation of cellular immunity including strong antigen-specific proliferation and cytokine production. In CF patients priming of the cellular immune system towards a Th1-like pattern would be of potential advantage. Therefore, confirmatory analyses in immunized CF patients with and without chronic infection with P. aeruginosa are foreseen.     

Cellular immunity in healthy volunteers treated with an octavalent conjugate Pseudomonas aeruginosa vaccine

Humoral immunity in response to an octavalent O-polysaccharide-toxin A conjugate Pseudomonas aeruginosa vaccine is well studied, and a phase III clinical study in cystic fibrosis (CF) patients is currently ongoing. In contrast, little is known about cellular immunity induced by this vaccine. Fifteen healthy volunteers were immunized on days 1 and 60. Parameters of cellular immunity were studied before vaccination on day 1, and on day 74. Analyses included flow cytometry of whole blood and antigen-induced proliferation of and cytokine production by lymphocyte cultures. The effects of immunization on the composition of peripheral blood lymphocytes as determined by flow cytometry were minor. In contrast, after immunization a highly significant increase of proliferation in response to stimulation with detoxified toxin A was noted: the stimulation index rose from 1.4 on day 1 to 42.2 on day 74 (restimulation with 0.4 microg/ml; P = 0.003). Immunization led to significant production of interferon (IFN)-gamma and tumour necrosis factor (TNF)-alpha by antigen-stimulated lymphocytes. In contrast, no significant induction of interleukin (IL)-4 or IL-10 was observed. In conclusion, immunization of healthy volunteers led to activation of cellular immunity including strong antigen-specific proliferation and cytokine production. In CF patients priming of the cellular immune system towards a Th1-like pattern would be of potential advantage. Therefore, confirmatory analyses in immunized CF patients with and without chronic infection with P. aeruginosa are foreseen.     

对几种含绿脓杆菌脂多糖的物质及其抗感染保护作用的初步观察

对绿脓杆菌感染防御性抗原的研究,特别是对绿脓杆菌表面抗原的研究,一直受到研究者的重视。近些年在临床应用上也有不少进展。在美国,Alexander 等研制的绿脓杆菌表面物质7价疫苗于1968年开始试用于临床,使烧伤患者因绿脓杆菌感染的死亡率下降。英国的 Jones 等研制出绿脓杆菌表面抗原多价疫苗,1976年完成系统的实验     

耐亚胺培南铜绿假单胞菌的分布及耐药性分析

目的:了解耐亚胺培南铜绿假单胞菌的感染情况及其耐药特性,为临床合理使用抗生素及防治耐药菌感染提供参考。方法:收集汕头大学医学院第一附属医院2005年4月到2006年4月间分离的92株耐亚胺培南的铜绿假单胞菌,VITEK-60全自动微生物鉴定仪及其配套试剂(GNS-506、GNS-120、GNS-114)进行细菌鉴定及测定其对多种抗生素的耐药性,肉汤二倍稀释法测定其对亚胺培南的MIC值。结果与结论:耐亚胺培南的铜绿假单胞菌感染主要发生神经外科、外科ICU、呼吸科及ICU和神经内科,对亚胺培南的耐药多为中低度耐药(MIC≤32 mg.L-1),对其它多种抗生素的耐药率均达到100%,仅头孢哌酮/舒巴坦复合制剂保持了较高的敏感率,作为经验性用药可考虑选用。     

铜绿假单胞菌外毒素A的抗原性及其与辅助细胞的关系

目的　研究铜绿假单胞菌外毒素A(PE)的某些抗原性及其与辅助细胞的关系。方法用MTT法观察PE在有无辅助细胞参与条件下对鼠脾淋巴细胞的刺激作用 ,并用鼠细胞毒性T细胞株CTLL进行证实。结果　PE在 0 0 1～ 10 0ng/ml浓度范围能刺激鼠脾淋巴细胞增殖 ,PE的丝裂原作用无需粘附细胞的辅助 ,但粘附细胞及其粘附细胞的PE刺激上清能协同PE对鼠脾淋巴细胞的刺激作用。PE在丝裂原作用范围内能刺激CTLL细胞生长 ,并与IL 2有协同作用。PE在体内能使小鼠脾淋巴细胞自发淋转率增高 ,对ConA刺激的增殖反应增强 ,但对淋巴细胞自发分泌IL 2和ConA诱导IL 2的产生水平无影响。结论　PE在无辅助细胞参与条件下也能刺激淋巴细胞增殖