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1.
目的研究血流感染产ESBLs肺炎克雷伯菌的毒力基因和基因分型特点。方法采用PCR检测菌株中高毒力因子、荚膜血清型以及ST分型;采用微量肉汤稀释法对菌株进行药敏试验;采用加克拉维酸的复合药(头孢他啶/克拉维酸或头孢噻肟/克拉维酸)与单药(头孢噻肟或头孢他啶)的药敏纸片组合进行肺炎克雷伯菌产ESBLs的表型确证试验。结果 128株血流感染肺炎克雷伯菌中,有23株产ESBLs(产ESBLs组),占17.97%(23/128);105株不产ESBLs(非产ESBLs组),占82.03%(105/125)。本地区血流感染肺炎克雷伯菌主要流行ST型别为ST23、ST65、ST37和ST29,其中ST23、ST29、ST65为非产ESBLs的优势ST型别菌株,而在产ESBLs菌株中无优势型别。两组菌在高黏液表型、荚膜血清型和毒力基因分布上差异均无统计学意义(P0.05)。产EBSLs组中发现8株高毒力产EBSLs肺炎克雷伯菌。结论临床诊疗中需在肺炎克雷伯菌耐药株中识别出高毒力肺炎克雷伯菌并给与及时的治疗,避免其并发症的发生。  相似文献   

2.
目的评价三种方法测定替加环素对多重耐药菌药物敏感的准确性。方法分别采用K-B法、Vitek 2法及MTS法检测临床分离的82株多重耐药细菌(MRSA、VRE、耐碳青霉烯类大肠埃希菌、耐碳青霉烯类肺炎克雷伯杆菌、耐碳青霉烯类鲍曼不动杆菌),比较其结果的差异性。结果 MTS法检测13株MRSA、10株VRE测得的替加环素MIC50和MIC90分别为0.25、0.064 mg/L,0.50、0.125 mg/L;Vitek 2法测MRSA、VRE的MIC50和MIC90分别为0.5、0.25 mg/L,1、0.5 mg/L;MTS法检测15株耐碳青霉烯类大肠埃希菌、19株耐碳青霉烯类肺炎克雷伯杆菌、28株耐碳青霉烯类鲍曼不动杆菌测得的替加环素MIC50和MIC90分别为0.25、0.5、1 mg/L,0.25、1、2 mg/L;Vitek 2法测耐碳青霉烯类大肠埃希菌、耐碳青霉烯类肺炎克雷伯杆菌、耐碳青霉烯类鲍曼不动杆菌分别为0.25、1、2 mg/L,1、1、4 mg/L;K-B法的替加环素对五种多重耐药菌依序的敏感率分别为100.0%、100.0%、66.7%、79.0%、78.0%。与MTS比较,其他两种方法测定MRSA、VRE的分类一致性(categorical agreement,CA)均为100.0%,其他三种CA分别为86.7%/73.3%、89.5%/84.2%、78.6%/89.3%;重大误差(major error,ME)分别为6.7%/6.7%、5.3%/5.3%、0.0%/3.6%;小误差(minor error,Me)分别为13.3%/13.3%、10.5%/10.5%、17.9%/21.4%。结论替加环素对各种多重耐药菌的每种测定方法敏感率存在差异,对耐碳青霉烯类鲍曼不动杆菌,使用K-B法来作为首选,而对耐碳青霉烯类大肠埃希菌、耐碳青霉烯类肺炎克雷伯杆菌及MRSA、VRE来说,Vitek 2法仍作为其敏感性的常规操作。需制定较方便合适的方法来指导临床用药。  相似文献   

3.
大熊猫源大肠杆菌及肺炎克雷伯氏菌对消毒剂耐药性研究   总被引:1,自引:0,他引:1  
本实验对大熊猫肠道分离的88株大肠杆菌、32株肺炎克雷伯氏菌对季铵盐类消毒剂BC、CTPC、CTAB及DDAC的最小抑菌浓度(MIC)值进行测定,并扩增了消毒剂的耐药基因。结果显示,大肠杆菌对季铵盐类消毒剂MIC值为:BC的MIC值介于8~128 mg/L;CTPC的MIC值在32~256 mg/L之间;CTAB的MIC值为64~512 mg/L;DDAC的MIC值介于8~128 mg/L。肺炎克雷伯氏菌对季铵盐类消毒剂的耐药情况为:BC的MIC值介于16~512 mg/L;CTPC的MIC值在64~256 mg/L之间;CTAB的MIC值介于128~512 mg/L;DDAC的MIC值介于8~64 mg/L。可见,肺炎克雷伯氏菌对季铵盐类消毒剂的MIC值要大于大肠杆菌对季铵盐类消毒剂的MIC值。耐药基因检测结果表明,大肠杆菌季铵盐类消毒剂的染色体型耐药基因扩增率为68.18%~98.86%,最高为sug E(98.86%),emr E最低(68.18%),没有检测出qac E、qac F、qac G,检出率最高的可移动遗传元件介导耐药基因为qac EΔ1(19.31%)。肺炎克雷伯氏菌的染色体型耐药基因检出率为13.64%~28.41%,ydg E最高(28.14%),emr E检出率最低(13.64%),可移动遗传元件介导耐药基因sug E(p)检出率最高(6.82%),qac EΔ1、qac F、qac G基因未检出。测定大熊猫源大肠杆菌及肺炎克雷伯氏菌对消毒剂的耐药性,对圈养大熊猫消毒剂的规范使用,防控大熊猫细菌性疾病以及细菌对消毒剂耐药性有着重要意义。  相似文献   

4.
目的 调查血液分离的肺炎克雷伯菌的耐药谱.方法 收集温州医学院附属第一医院2005年1月至2009年9月间血液分离的肺炎克雷伯菌,采用全自动微生物分析仪对肺炎克雷伯菌进行菌种鉴定和药敏试验,超广谱β-内酰胺酶的检测采用仪器法.舒普深和美洛培南的药敏试验采用K-B法.结果 80株分离自血液的肺炎克雷伯菌主要分离自患有肝胆疾病、血液系统疾病、呼吸系统疾病和神经系统疾病的患者,分别占20.0%、17.5% 、15.0%和13.7%.80株肺炎克雷伯菌中,10株ESBLs阳性,阳性率为12.5%(10/80).除肺炎克雷伯菌对氨苄西林100%耐药外,对其他15种被测抗菌药物的耐药率全部低于20%,所有被测菌株对亚胺培南和美洛培南全部敏感,对其他9种抗菌药物的耐药率也低于10%.结论 血液分离的肺炎克雷伯菌主要来自患有肝胆疾病、血液系统疾病和神经系统疾病的患者.血液分离的肺炎克雷伯菌的ESBLs检出率非常低,且对常用抗菌药物的耐药率非常低.  相似文献   

5.
【背景】随着细菌耐药性的增强,产超广谱β-内酰胺酶肺炎克雷伯菌的出现严重危害食品安全和人体健康。蓝莓中含有丰富的多酚和花青素,是天然抗菌材料的优选。【目的】分析蓝莓提取物对3株产超广谱β-内酰胺酶肺炎克雷伯菌的抑制活性及作用机制,并以牛乳为样品检测食品基质对蓝莓提取物抑菌活性的影响。【方法】利用甲醇制备巴尔德温和黑珍珠蓝莓提取物并检测提取物中总酚和花青素含量,利用纸片扩散法检测肺炎克雷伯菌的耐药性,利用最小抑菌浓度(minimum inhibitory concentration,MIC)、最小杀菌浓度(minimum bactericidal concentration,MBC)和生长曲线研究蓝莓提取物的抗菌活性,通过共聚焦激光扫描显微镜观察蓝莓提取物对细胞膜完整性的影响,并检测其在牛乳中的抑菌活性。【结果】巴尔德温和黑珍珠蓝莓提取物中的总酚含量分别为2.3 mg/g和3.5 mg/g,花青素含量分别为67.5 mg/100 g和92.5 mg/100 g。两种蓝莓提取物对肺炎克雷伯菌KP106、KP305和KP408的MIC均为25mg/mL,MBC均为50mg/mL。生长曲线表明...  相似文献   

6.
肺炎克雷伯菌是一种常见致病菌,根据毒力和致病特点不同,可分为毒力相对较弱的经典肺炎克雷伯菌和高毒力肺炎克雷伯菌。目前,关于肺炎克雷伯菌分子致病机制研究较多且较清楚的主要有荚膜、脂多糖、黏附素和铁载体。这四大类毒力因子在经典肺炎克雷伯菌中也存在,但在高毒力肺炎克雷伯菌中存在的频率更高,并引发不同的免疫应答,从而使高毒力肺炎克雷伯菌具有特征性表型。本文就此进行详细介绍和讨论。  相似文献   

7.
台萃  旷代  张萍  许杰  张薇  罗倩 《微生物学通报》2022,49(3):1200-1213
【背景】条件致病菌肺炎克雷伯菌是医源性感染最重要的革兰氏阴性菌之一,目前对该病原菌的核酸检测方法存在费时费力、灵敏度低、准确性差等问题。【目的】建立基于芯片式数字PCR的肺炎克雷伯菌检测方法。【方法】依据肺炎克雷伯菌的16SrRNA基因保守序列设计特异性引物和TaqMan探针,通过与实时荧光定量PCR的比较分析,确定了芯片式数字PCR方法的检测范围和最佳反应条件,并进行了方法特异性、灵敏性分析及临床菌株的检测。【结果】芯片式数字PCR检测灵敏度比实时荧光定量PCR提高了约1.5个数量级,最低检出限可达到3.77 copies/μL;优化后的芯片式数字PCR特异性与实时荧光定量PCR结果一致,方法的相对标准偏差(relative standard deviation,RSD)均小于25%;本研究利用优化后的芯片式数字PCR方法共检测了28株临床菌株,检测到14株为肺炎克雷伯菌,14株为其他种属,这也与实时荧光定量PCR检测结果一致。【结论】采用芯片式数字PCR技术建立了肺炎克雷伯菌核酸检测的绝对定量方法。该方法特异性好、灵敏度高、准确度高,适合肺炎克雷伯菌的核酸检测和定量分析,也为其他临...  相似文献   

8.
本研究在黄喉拟水龟中分离的肺炎克雷伯菌基础上,根据肺炎克雷伯菌Ⅲ型菌毛的Mrk D基因序列设计引物,通过对SYBR-GreenⅠ荧光定量PCR反应条件、特异性、灵敏性实验进行调节优化,建立了肺炎克雷伯菌的SYBR-GreenⅠ荧光定量PCR检测方法。研究结果表明,建立的肺炎克雷伯菌荧光定量PCR方法,检测时间短,用时73 min;特异性强,对非肺炎克雷伯菌无交叉反应;灵敏度高,检测肺炎克雷伯菌DNA的最低检测量为2.78 fg。该方法的建立,为肺炎克雷伯菌的辅助诊断、流行病学调查、毒力基因的分析提供科学借鉴。  相似文献   

9.
目的探讨胶体纳米银对产超广谱β-内酰胺酶(ESBLs)肺炎克雷伯菌的抑制作用。方法以产ESBLs肺炎克雷伯菌为研究对象,采用涂布法检测杀菌作用,肉汤微量稀释法测量最低抑菌浓度(MIC),电镜法观察胶体纳米银对产ESBLs肺炎克雷伯菌的作用机理。结果≥0.5μg/mL的胶体纳米银对产ESBLs的肺炎克雷伯菌具有100%杀菌作用;≥0.05μg/mL的胶体纳米银对产ESBLs的肺炎克雷伯菌也具有明显的杀菌作用;5μg/mL胶体纳米银对产ESBLs肺炎克雷伯菌5、15、30和60 min均有明显的杀菌作用;胶体纳米银对产ESBLs肺炎克雷伯菌的MIC为3.125μg/mL;不同因素对胶体纳米银的杀菌作用,蛋白因素影响显著(P0.05);胶体纳米银对产ESBLs肺炎克雷伯菌的形态学有明显影响。结论胶体纳米银对产ESBLs肺炎克雷伯菌具有明显的抑制作用,这些结果将为胶体纳米银的临床应用提供了实验依据。  相似文献   

10.
目的分析新生儿血培养阳性标本中各病原菌分布情况及与hs-CRP的相关性。方法统计分析2015年1月至2016年1月大连市妇幼保健院新生儿ICU血培养临床资料并采用CRP检测试剂盒对血培养阳性的患者进行hs-CRP的检测。结果血培养阳性结果中,凝固酶阴性葡萄球菌46株,占65.7%,肺炎克雷伯菌8株,占11.4%,大肠埃希菌5株,占7.1%,肠杆菌、鲍曼不动杆菌、洛非不动杆菌各2株,分别占2.9%,摩根摩根菌、B群链球菌、金黄色葡萄球菌、肠球菌、微球菌各1株,分别占1.4%;hs-CRP的检出量,革兰阴性菌感染组为(20.60±3.40)mg/L,革兰阳性菌感染组为(15.80±2.30)mg/L,正常对照组为(4.10±0.95)mg/L。结论新生儿血培养阳性的主要致病菌为凝固酶阴性葡萄球菌、肺炎克雷伯菌和大肠埃希菌;有细菌感染的新生儿血中hs-CRP值升高,革兰阴性菌感染hs-CRP值高于革兰阳性菌。  相似文献   

11.
PriB is a primosomal protein required for the reinitiation of replication in bacteria. Here, we report the identification and characterization of a novel PriB protein in Klebsiella pneumoniae (KPN_04595; KpPriB). Unlike the well-studied Escherichia coli PriB protein (EcPriB), which exists as a homodimer comprising 104-aa polypeptides, KpPriB forms a monomer of only 55 aa, due to the absence of the 49 aa N-terminus in KpPriB. Although this N-terminal region (1–49 aa) in EcPriB contains several important residues, such as K18, R34, and W47, which are crucial for ssDNA binding, we found that KpPriB binds ssDNA, but not ssRNA, with comparable affinity as that for EcPriB. Results from filter-binding assays demonstrate that the KpPriB–ssDNA interaction is cooperative and salt-sensitive. Substituting the residue K33 in KpPriB with alanine, the position corresponding to the classic ssDNA-binding residue K82 of EcPriB located in loop L45, significantly reduced ssDNA-binding activity and cooperativity. These results reveal that the 1–49 aa region of the classical PriB protein is unnecessary for ssDNA binding. On the basis of these findings, the structure–function relationships of KpPriB are discussed.  相似文献   

12.
Summary A clone bank of an indigenous plasmid ofEnterobacter agglomerans containing structural nitrogen-fixation (nif) genes was established in a non-mobilisable, multicopy derivative of the cosmid vector pHC79. The restriction enzyme Bam HI was used to establish the clone bank and it was found that 96% of the clones contained inserts. The clones containingnif-genes were identified by Southern hybridisation usingKlebsiella pneumoniae nif DNA (KpnifHDKY) as the radioactive probe. Thenif-genes ofE. agglomerans showed extensive homology to those ofK. pneumoniae but the restriction enzyme fragment patterns of thenif-genes ofE. agglomerans were different. The plasmid bornenif-genes ofE. agglomerans are clustered as inK. pneumoniae.  相似文献   

13.
Klebsiella pneumoniae is a ubiquitous opportunistic pathogen that colonizes at the mucosal surfaces in humans and causes severe diseases. Many clinical strains of K. pneumoniae are highly resistant to antibiotics. Here, we used fluorescence quenching to show that the flavonols galangin, myricetin, quercetin, and kaempferol, bearing different numbers of hydroxyl substituent on the aromatic rings, may inhibit dNTP binding of the primary replicative DnaB helicase of K. pneumoniae (KpDnaB), an essential component of the cellular replication machinery critical for bacterial survival. The binding affinity of KpDnaB to dNTPs varies in the following order: dCTP ~ dGTP > dTTP > dATP. Addition of 10 μM galangin significantly decreased the binding ability of KpDnaB to dATP, whereas the binding affinity of KpDnaB to dGTP that was almost unaffected. Our analyses suggest that these flavonol compounds may be used in the development of new antibiotics that target K. pneumoniae and other bacteria.  相似文献   

14.
The yqhD gene from Escherichia coli encoding 1,3-propanediol oxidoreductase isoenzyme (PDORI) and the tetracycline resistant gene (tetR) from plasmid pHY300PLK were amplified by PCR. They were inserted into vector pUC18, yielding the recombinant expression vector pUC18-yqhD-tetR. The recombinant vector was then cloned into Klebsiella pneumoniae ME-308. The overexpression of PDORI in K. pneumoniae surprisingly led to higher 1,3-propanediol production. The final 1,3-propanediol concentration of recombinant K. pneumoniae reached 67.6 g/l, which was 125.33% of that of the original strain. The maximum activity of recombinant PDORI converting 3-HPA to 1,3-PD reached 110 IU/mg after induction by IPTG at 31°C during the fermentation, while it was only 11 IU/mg under the same conditions for the wild type strain. The K m values of the purified PDORI for 1,3-propanediol and NADP were 12.1 mM and 0.15 mM, respectively. Compared with the original strains, the concentration of the toxic intermediate 3-hydroxypropionaldehyde during the fermentation was also reduced by 22.4%. Both the increased production of 1,3-propanediol and the reduction of toxic intermediate confirmed the significant role of 1,3-propanediol oxidoreductase isoenzyme from E. coli in converting 3-hydroxypropionaldehyde to 1,3-propanediol for 1,3-PD production.  相似文献   

15.
Klebsiella pneumoniae is one of the major pathogens causing global multidrug-resistant infections. Therefore, strategies for preventing and controlling the infections are urgently needed. Phage depolymerase, often found in the tail fiber protein or the tail spike protein, is reported to have antibiofilm activity. In this study, phage P560 isolated from sewage showed specific for capsule locus type KL47 K. pneumoniae, and the enlarged haloes around plaques indicated that P560 encoded a depolymerase. The capsule depolymerase, ORF43, named P560dep, derived from phage P560 was expressed, purified, characterized and evaluated for enzymatic activity as well as specificity. We reported that the capsule depolymerase P560dep, can digest the capsule polysaccharides on the surface of KL47 type K. pneumoniae, and the depolymerization spectrum of P560dep matched to the host range of phage P560, KL47 K. pneumoniae. Crystal violet staining assay showed that P560dep was able to significantly inhibit biofilm formation. Further, a single dose (50 μg/mouse) of depolymerase intraperitoneal injection protected 90%–100% of mice from lethal challenge before or after infection by KL47 carbapenem-resistant K. pneumoniae. And pathological changes were alleviated in lung and liver of mice infected by KL47 type K. pneumoniae. It is demonstrated that depolymerase P560dep as an attractive antivirulence agent represents a promising tool for antimicrobial therapy.  相似文献   

16.
【背景】肺炎克雷伯菌(肺克)是医院感染和社区获得性感染的重要病原菌,由于近年来肺克菌株耐药情况越来越严重,使得其感染在临床治疗上更加棘手。目前肺克感染引起化脓性肌炎的罕见病例越来越多,而深层肌肉组织感染可能会形成厌氧环境,钼酸盐转运体ModABC是细菌厌氧硝酸盐呼吸所必需。前期研究发现ModA可能与肺克毒力正相关。【目的】研究钼酸盐转运体ModABC对肺克肌肉感染的作用及钨酸盐治疗的可能性。【方法】构建modA无痕缺失突变株与回补株,通过检测体外厌氧生长、硝酸还原酶活性和小鼠肌肉感染实验分析ModABC对肺克肌肉感染的作用及机制;通过钨酸盐处理(体外、体内)探讨钨酸盐治疗肺克肌肉感染的可能性及疗效。【结果】成功构建了modA无痕缺失突变株与回补株,发现modA基因敲除后肺克体外厌氧生长明显被极大地抑制、硝酸还原酶活性显著降低,小鼠肌肉脓肿模型显示敲除株ΔmodA感染肌肉脓肿大大消减,并且在肌内生长及侵袭受限;体外钨酸盐处理能够抑制野生株WT厌氧硝酸盐呼吸,在肌肉脓肿模型中也能显著抑制WT生长,但对敲除株ΔmodA无影响。【结论】钼酸盐转运体ModABC通过增强侵袭力和促进厌氧硝酸盐呼吸来提供适应优势而促进肺克肌肉感染,钨酸盐可以降低由ModA赋予的适应优势而对肺克肌肉感染具有一定的治疗作用。本研究有助于阐明钼离子对肺克致病性的作用机制及为其治疗提供新思路,为深入研究肺克尤其是耐碳青霉烯高毒力肺克感染的治疗奠定基础。  相似文献   

17.
Summary The capsule of Klebsiella pneumoniae type I and slime of Enterobacter aerogenes strain A3 (SL) was examined by electron microscopy using the freeze etch technique. The capsules of K. pneumoniae were found to be composed of several layers of polysaccharide 10 nm thick; while the polysaccharide slime of E. aerogenes strain A3 (SL) was found to be composed of a diffuse network of fibrils. This work represents the first effort to visualize the replica of the unfixed, partially hydrated bacterial capsule or slime in the electron microscope. The slime of E. aerogenes strain A3 (SL) which was purified, and then freeze etched, resembled the layered structure of the capsule of K. pneumoniae. It is suggested that the charge or dielectric constant of the slime polysaccharide polymers was altered during purification, thereby permitting the layering to occur.Paper presented at the Annual Meeting of the American Society for Microbiology, Philadelphia, Pa. (U.S.A.), 1972.  相似文献   

18.
肺炎克雷伯菌(Klebsiella pneumoniae)是在临床引起多种感染的常见条件致病菌之一。多重耐药肺炎克雷伯菌株的出现,给防控细菌感染带来了巨大阻力。肺炎克雷伯菌噬菌体编码的解聚酶是一种稳定性高、特异性强的生物酶,具有分解细菌胞外多糖、限制细菌生长等多种功能。解聚酶可为防控肺炎克雷伯菌感染提供新思路,在抗菌应用中具有广阔前景。本文就肺炎克雷伯菌噬菌体解聚酶的研究进展进行综述。  相似文献   

19.
The multi drug resistance Klebsiella pneumoniae in urinary tract infection is a common clinical problem in developing country like India. Use of random antibiotics, resulting multi drug resistance development, creates difficulties for treatment. In our present study, we investigated a strain of Klebsiella pneumoniae UTI 2 with multiple drug resistance, which was isolated from urine of a post operative woman patient (50 years) suffering from urinary tract infection with high fever. This strain is resistant to 36 antibiotics and sensitive to cefotaxime (Ce) and imipenem (I). After curing of plasmids, we observed that, 55% of drug resistant loci of K. pneumoniae UTI 2 are chromosomal and 40% are plasmid encoded. The organism is sensitive to 5% of drugs tested, i.e. Ce and I. This study contributes to understand the drug resistance of Klebsiella pneumoniae, which will enable better clinical management of catheter-associated urinary tract infections, a major health problem.  相似文献   

20.
Hydroalcoholic propolis extracts from the bee species Melipona quadrifasciata have been shown to possess antimicrobial activity against different mollicute strains, but a methanolic extract (ME) could contain an increased diversity of nonpolar bioactive components with a potentially higher antimicrobial activity. The ME obtained by maceration of the propolis sample was fractionated with solvents of different polarities and then, purified by silica gel column chromatography through biomonitoring of its antimicrobial activity against mollicute strains. Analysis by gas chromatography-mass spectrometry (GC/MS) enabled the identification of compounds using the NIST library. Minimum inhibitory concentrations (MICs) of the samples were determined by broth microdilution. Anti-adhesive assays were performed with Mycoplasma pneumoniae cells. The hexane (MIC=62.5 mg/L) and dichloromethane (MIC=125 mg/L) fractions presented the most promising results against M. pneumoniae. They were fractionated into 74 subfractions, and even the best ones did not show better results (MIC>250 mg/L) than their original fractions, likely due to the loss of terpene compounds that seem to act in synergy. The dichloromethane subfraction FD4 was highlighted in the anti-adhesive assay with an inhibitory activity of 21.6 %. A synergistic effect of the nonpolar compounds in M. quadrifasciata propolis may be responsible for its antibacterial activity, but several purified components can improve its anti-adhesive properties.  相似文献   

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