粘液型铜绿假单胞菌耐药特性的实验研究

目的探讨粘液型铜绿假单胞菌的耐药性,为临床治疗选药提供依据.方法应用微量稀释法分别测试粘液型与非粘液型铜绿假单胞菌对常见1 2种抗生素的敏感性,并进行统计分析.结果粘液型铜绿假单胞菌对阿米卡星、妥布霉素和亚胺培南的敏感率均为100%,对头孢他定、复方派拉西林、复方替卡西林、派拉西林和奈替米星的敏感率均分别为93%,对替卡西林和环丙沙星的敏感率分别为86%,和79%,对复方新诺明的敏感率为47%.结论粘液型铜绿假单胞菌的体外耐药性较弱,且明显弱于非粘液型铜绿假单胞菌的耐药性(P＜0.005),但在临床用药时必须考虑粘液型铜绿假单胞菌在体内存在有生物膜的影响因素.     

创伤外科62株铜绿假单胞菌体外抗菌药物敏感性分析

目的了解创伤外科铜绿假单胞菌对亚胺培南等12种抗菌药物的抗菌活性,指导临床合理用药。方法利用WHONET软件对62株创伤外科分离的铜绿假单胞菌药敏试验结果进行统计和分析。结果铜绿假单胞菌对阿米卡星敏感性最高(96.77%),依次为哌拉西林/他唑巴坦、亚胺培南、哌拉西林、庆大霉素、妥布霉素、左旋氧氟沙星,敏感率分别为87.10%、72.58%、70.97%、70.60%、69.35%、66.13%。敏感率小于60%抗菌药物分别是头孢他啶、氨曲南、头孢吡肟、环丙沙星、替卡西林/克拉维酸。痰标本中的铜绿假单胞菌对抗菌药物的敏感率均小于分泌物中的铜绿假单胞菌。结论创伤外科铜绿假单胞菌对多种抗菌药物保持较高的敏感性;铜绿假单胞菌对抗菌药物的耐药性呈现逐年增加的趋势。     

2010年至2014年我医院铜绿假单胞菌耐药性分析

目的：分析我院临床分离的铜绿假单胞菌对抗菌药物的耐药性及5年来的变化趋势,为临床的合理用药提供科学依据。方法收集2010年1月至2014年12月我院临床送检的感染患者标本,分离铜绿假单胞菌,采用黑马迪尔的96NE板对铜绿假单胞菌菌株进行药敏试验,分析其耐药性及变化趋势。结果从临床标本中共分离出486株铜绿假单胞菌菌株,主要来源于痰液(占72.2％),科室主要分布于重症监护病房(ICU)、呼吸内科和神经外科等。2010年至2014年铜绿假单胞菌对12种常用抗生素的耐药性呈现出不同程度的上升趋势,其中多重耐药铜绿假单胞菌为70株(占14.4％)。铜绿假单胞菌对头孢哌酮/舒巴坦和阿米卡星的耐药率最低,分别为9.5％和10.9％,对替卡西林/克拉维酸的耐药率最高,为32.7％。结论医院内感染铜绿假单胞菌的耐药率很高,临床医师在治疗时,应结合药敏结果合理使用抗生素。     

黏液型铜绿假单胞菌耐药性分析

目的探讨黏液型铜绿假单胞菌的耐药性,为临床治疗选药提供依据。方法参考美国临床实验室标准化协会（CLSI）M100-S20文件,采用微量肉汤稀释法分别测定黏液型与非黏液型铜绿假单胞菌对常用13种抗菌药物的敏感性,并进行统计分析。结果黏液型铜绿假单胞菌对阿米卡星、美罗培南、亚胺培南、头孢吡肟、妥布霉素星的敏感性均为100.0%,对头孢他啶、哌拉西林、哌拉西林-他唑巴坦、替卡西林-克拉维酸、左氧氟沙星的敏感性在74.0%～94.0%之间,对环丙沙星和复方磺胺甲口恶唑的敏感性为68.0%和49.0%。非黏液型铜绿假单胞菌对阿米卡星、美罗培南、亚胺培南、头孢吡肟、妥布霉素的敏感性在56.0%～80.0%之间,对头孢他啶、哌拉西林、哌拉西林-他唑巴坦等药物的敏感性在38.0%～76.0%之间,对复方磺胺甲口恶唑全耐药。黏液性铜绿假单胞菌的耐药性明显弱于非黏液型铜绿假单胞菌。结论黏液型铜绿假单胞菌体外药物敏感试验耐药性较弱。临床治疗选药时必须参考黏液型铜绿假单胞菌在体内存在有生物膜的影响因素,及时调整给药方案。     

铜绿假单胞菌的耐药性及多重耐药机制

目的了解铜绿假单胞菌临床分离株的耐药性及耐药机制,指导临床合理选用抗生素。方法应用英国先德微生物分析系统检测药物敏感性,通过改良酶提取物头孢西丁和头孢曲松三维试验检测AmpC酶和ESBLs,K-B纸片扩散法检测金属β内酰胺酶。结果74株临床分离铜绿假单胞菌对亚胺培南的敏感率最高,敏感率达82.4%。对头孢吡肟、阿米卡星、派拉西林、环丙沙星、妥布霉素的敏感性较高。单产ESBLs、同时产ESBLs和AmpC酶、单产AmpC酶和单产金属β内酰胺酶的检出率分别为16.2%,9.4%,5.4%,4.0%。结论临床分离铜绿假单胞菌的耐约现象不容忽视,产生高活性β内酰胺酶是导致其耐药的机制之一,亚胺培南仍是治疗铜绿假单胞菌感染最有效的约物。     

亚胺培南耐药非发酵菌流行进展及耐药谱分析

[目的]了解亚胺培南耐药非发酵菌在我院的流行进展及对其他常用抗菌药物的耐药性，为临床合理选用抗生素提供参考。[方法]全部细菌用ATB Expression鉴定到种，铜绿假单胞菌及鲍曼不动杆菌药敏采用纸片扩散法，统计软件为WHONET5；嗜麦芽窄食单胞菌药敏采用ATB配套的药敏卡。[结果]4年来我院铜绿假单胞菌对亚胺培南耐药性有逐年增长趋势（χ^2=13．44，P〈0．05）；鲍曼不动杆菌对亚胺培南耐药性变化不明显，耐药率平均为2．4％；对铜绿假单胞菌和鲍曼不动杆菌亚胺培南耐药株体外抗菌活性均较强的是头孢哌酬／舒巴坦、环丙沙星，其他抗生素耐药率均大于50％；对嗜麦芽窄食单胞菌耐药率最低的抗生素仍是复方磺胺（9．34％），其次是环丙沙星（25．2％）、复方替卡西林（43．0％）。[结论]近年来铜绿假单胞菌对亚胺培南耐药有升高趋势，值得密切关注；亚胺培南耐药的非发酵菌多重耐药严重，尤其对β-内酰胺类抗生素和氨基糖苷类；对嗜麦芽窄食单胞菌最为有效的抗生素仍是复方磺胺，亚胺培南耐药非发酵菌经验用药可选头孢哌酮／舒巴坦或环内沙星，但应根据药敏结果随时调整用药。     

291株铜绿假单胞菌的分离及耐药性分析

目的分析导致临床感染的291株铜绿假单胞菌的来源分布及其耐药情况，为临床预防感染以及合理用药提供依据。方法采集来自我院各临床科室的送检标本，进行细菌学培养鉴定及药敏试验。结果铜绿假单胞菌以呼吸道和伤口分泌物为主要临床感染来源，抗感染药物中耐药率最高的是复方新诺明（89．69％）、替卡西林／克拉维酸（45．36）、奈替米星（41．92），其耐药情况较严重。结论铜绿假单胞菌耐药情况均较严重，需高度重视，合理谨慎使用抗生素是延缓其耐药株快速升高的最好办法。     

非发酵菌的临床分布及耐药性分析

目的了解2002-2005年本院非发酵菌的分布及耐药性分析,为临床合理选用抗生素提供依据。方法细菌鉴定、药敏实验检测采用VITEK-32全自动微生物分析仪。结果4年间非发酵菌的检出菌株为422株,其中以铜绿假单胞菌为最多（70．9％）,其次为不动杆菌（14．9％）和嗜麦芽假单胞菌（6．4％）。非发酵菌在痰液中分离率最高（65．6％）。亚胺培南和头孢他啶对铜绿假单胞菌敏感率最高;头孢唑林和头孢曲松对铜绿假单胞菌的敏感率最低;复方新诺明对嗜麦芽假单胞菌的敏感率最高,其他抗生素敏感率较低;不动杆菌敏感率以哌拉西林／他唑巴坦和亚胺培南偏高。结论非发酵菌为医院感染的主要致病菌,且对抗菌药物呈多重耐药,含酶抑制剂复方型抗菌药物、亚胺培南和头孢他啶为治疗非发酵菌感染的首选药物。     

铜绿假单胞菌的感染分布及药敏分析

目的 研究铜绿假单胞菌的感染分布及对常用的16种抗生素的体外抗菌活性分析，以利于临床合理选用抗生素。方法 对从患者标本中分离出来的368株铜绿假单胞菌进行药敏试验并结合临床相关资料进行分析。细菌菌种鉴定采用法国生物梅里埃公司生产的VITEK-32全自动微生物分析仪。药敏试验采用K-B琼脂纸片扩散法，M-H培养基采用法国生物梅里埃公司产品。结果 由铜绿假单胞菌导致感染的主要部位是呼吸道，其次为各种伤口及术后感染部位。铜绿假单胞菌在不同科室的分布情况显示，主要集中在干保病房、呼吸内科及SICU，而其在不同病种的分布显示，各种肺部疾病的总比例高达60．9％，而各种术后的感染情况也较高，共占9．0％。虽然亚安培南／西司他汀在治疗铜绿假单胞菌的敏感率仍为最高，但仅为77．6％，以往在报道中敏感率较高的抗生素如美罗培南、派拉西林、头孢他啶、头孢吡肟、头孢哌酮／舒巴坦等在此也出现了不同程度的下降。本组体外药敏试验结果提示对铜绿假单胞菌敏感率高于70％的抗生素只有6种，即亚安培南／西司他汀、派拉西林、阿米卡星、头孢他啶、头孢吡肟、美洛培南，而且没有一种高于80％，而多重耐药情况相对较好。结论 应加强高龄患者和免疫机能低下患者的感染监测，加强相关科室的消毒隔离，认真执行无菌操作，有效地切断耐药菌株的传播途径，降低由铜绿假单胞菌引起的院内感染。临床应根据体外药敏试验的结果，合理选择抗菌药物。     

临床分离铜绿假单胞菌分布及耐药性分析

目的 了解铜绿假单胞菌的临床分布及耐药性特性。方法 对医院2007年7月至2008年10月细菌培养和药敏试验的结果进行回顾性分析。结果 共分离铜绿假单胞菌335株,占总病原菌9.2%;主要标本来源是痰液,占77.6%。高发病区是ICU病房。铜绿假单胞菌对丁胺卡那霉素、哌拉西林/他唑巴坦、妥布霉素、左氧氟沙星、头孢吡肟、庆大霉素、替卡西林及环丙沙星12种常用抗菌药物耐药率小于10%。对亚胺培南不敏感的铜绿假单胞菌对氨曲南、头孢他啶、环丙沙星、左氧氟沙星、哌拉西林/他唑巴坦的耐药率明显高于对亚胺培南敏感的铜绿假单胞菌(P<0.05)。结论 铜绿假单胞菌多重耐药现象普遍存在,建议治疗选用丁胺卡那霉素、哌拉西林/他唑巴坦、妥布霉素。     

VITEK2 Compact全自动微生物分析仪对黏液型和非黏液型铜绿假单胞菌药敏检测评价

目的 评价VITEK2 Compact全自动微生物分析仪对黏液型和非黏液型铜绿假单胞菌药敏检测结果的准确性。方法 对某院分离的29株黏液型铜绿假单胞菌和30株非黏液型铜绿假单胞菌同时以VITEK2 Compact分析仪法及琼脂稀释法进行药物敏感性试验,以琼脂稀释法为参考方法进行统计学分析。结果黏液型铜绿假单胞菌VITEK2 Compact分析仪法药敏结果的标准符合率(CA)为84.69%,严重错误率(VME)为3.20%,重大错误率(ME)为2.13%,一般错误率(MIE)为9.96%; 非黏液型铜绿假单胞菌VITEK2 Compact分析仪法药敏结果的标准符合率(CA)为94.33%,严重错误率(VME)为0.67%,重大错误率(ME)为1.67%,一般错误率(MIE)为3.33%。两种铜绿假单胞菌VITEK2 Compact分析仪法药敏结果的VME,MIE,CA相比较,差异有统计学意义(χ²=5.02,10.44,14.55,P<0.05)。黏液型铜绿假单胞菌VITEK2 Compact分析仪法药敏结果的CA比非黏液型铜绿假单胞菌低,且<90%,而VME,MIE均比非黏液型铜绿假单胞菌高。结论 VITEK2Compact全自动微生物分析仪对非黏液型铜绿假单胞菌药敏检测结果准确可靠,对黏液型铜绿假单胞菌药敏检测结果准确性较低,黏液型铜绿假单胞菌建议用其它方法做药物敏感性试验。     

A case of K cell deficiency with diabetes mellitus and Graves'' disease

Alginate, an acetylated polymer of D-mannuronic and L-guluronic acid obtained from a mucoid strain of Pseudomonas aeruginosa was shown to inhibit the binding of an isogenic non-mucoid revertant to mouse peritoneal and pulmonary macrophages. Inhibition of bacterial binding by the alginate was also demonstrated in tests with other non-mucoid P. aeruginosa strains and a strain of Staphylococcus albus. Since the mucoid form of P. aeruginosa eventually predominates in chronic P. aeruginosa infection in patients with cystic fibrosis, it is postulated that the alginate's inhibition of binding gives mucoid forms a selective advantage over non-mucoid forms against macrophage defence mechanisms in the lung.     

Characterization of paired mucoid/non-mucoid Pseudomonas aeruginosa isolates from Danish cystic fibrosis patients: antibiotic resistance, beta-lactamase activity and RiboPrinting

The purpose of this study was to characterize 42 paired mucoid and non-mucoid Danish cystic fibrosis (CF) Pseudomonas aeruginosa isolates collected in 1997, by RiboPrinting, antibiotic susceptibility and beta-lactamase activity. Eight P. aeruginosa isolates collected before 1991 were included for comparison. Eighteen of the 42 paired mucoid and non-mucoid isolates showed the same ribotype; the remaining 24 belonged to different ribogroups. Mucoid isolates showed higher susceptibility to antibiotics and lower beta-lactamase activity compared with non-mucoid isolates. Significant differences (P < or = 0.01) between mucoid and non-mucoid isolates were found for the meropenem and colistin MICs for the isolates with the same ribotype, and for the MICs of ceftazidime, piperacillin, aztreonam, meropenem, tobramycin, ciprofloxacin and in the basal levels of beta-lactamase for the paired isolates belonging to different ribogroups. A dominant ribotype 73-S2 with hyperinducible beta-lactamase production and significantly higher MICs of piperacillin, meropenem and tobramycin compared with the other major ribotypes (73-S1, 207-S3 and 227-S8) was present among the 84 CF isolates. The isolates collected before 1991 had an antibiotic susceptibility pattern similar to the 1997 isolates. Despite prolonged and intensive antibiotic treatment, susceptible mucoid isolates were isolated from the CF sputum, possibly because these bacteria are protected from the selective pressure of antibiotics by the resistant non-mucoid isolates co-existing in the biofilm in the lungs of CF patients.     

The effect of sublethal concentrations of aminoglycosides on adherence of Pseudomonas aeruginosa to hamster tracheal epithelium

Perfused hamster tracheal explants were used to examine the adherence of mucoid and non-mucoid strains of Pseudomonas aeruginosa to intact tracheal epithelium when grown in 0.5 MIC of tobramycin or gentamicin. Tracheal explants were perfused for 2 h with 10(7) cfu of P. aeruginosa grown overnight in trypticase soy broth containing 0.5 MIC of tobramycin or gentamicin or without antibiotics. After infection, the explants were washed and a 4 mm section was homogenized, diluted and plated for colony counts. Mucoid strains of P. aeruginosa grown in the presence of the aminoglycosides did not produce alginate and were not as adherent as the same strains which were not grown in antibiotics. Adherence of non-mucoid strains of P. aeruginosa grown in sublethal concentrations of the aminoglycosides was not significantly reduced compared with the adherence of the same strains which were not exposed to antibiotics. These results indicate that mucoid strains of P. aeruginosa growing in the presence of sublethal concentrations of aminoglycosides do not produce alginate and may not colonize the epithelial surface.     

Opsonization of mucoid and non-mucoid Pseudomonas aeruginosa by serum from patients with cystic fibrosis assessed by a chemiluminescence assay

Since Pseudomonas aeruginosa (P. aeruginosa) is a major pathogen for patients with cystic fibrosis (CF), we compared serum from CF patients to serum from controls for opsonic activity against a mucoid and a non-mucoid strain of this organism. A chemiluminescence assay was employed to assess opsonic activity using control polymorphonuclear leukocytes and organisms opsonized with: (1) serum from CF patients who were colonized with P. aeruginosa; (2) serum from CF patients who were not colonized with this organism; and (3) pooled control serum. Serum from CF patients who were colonized with P. aeruginosa had 1.5-2-fold greater opsonic activity against mucoid and non-mucoid P. aeruginosa respectively than serum from non-colonized CF patients or pooled control serum. The increased activity was attributed to antibody, since adsorption of serum with the organism removed much of its opsonic activity. Heat inactivation also decreased opsonic activity indicating that complement plays an important role. We speculate that the increased levels of opsonic antibodies in patients colonized with P. aeruginosa may play a role in the pathogenesis of lung damage by triggering neutrophil migration to the lung.     

黏液型与非黏液型铜绿假单胞菌Cif基因表达研究

目的 比较黏液型和非黏液型铜绿假单胞菌囊性纤维化跨膜传导调节体抑制因子(Cif)基因表达差异,并结合临床资料比较对应患者白细胞(WBC)及C反应蛋白(CRP)等炎症指标的不同。方法 采用逆转录PCR和实时荧光定量PCR检测两种型别铜绿假单胞菌Cif基因的表达量。收集相应患者临床数据比较WBC数和CRP水平及其与Cif基因表达的相关性。结果 黏液型铜绿假单胞菌Cif基因表达量显著高于非黏液型铜绿假单胞菌,差异有统计学意义(t=2.09,P<0.05),黏液型铜绿假单胞菌组和非黏液型铜绿假单胞菌组的患者其WBC数和CRP水平差异无统计学意义(t=0.65,0.60,P>0.05); Cif基因表达与CRP水平相关性极弱(a=-0.061,R²=0.04),与WBC数相关性也极弱(a=0.095,R²=0.029)。结论 Cif基因表达可能与黏液型铜绿假单胞菌生物被膜的形成有关,可能为铜绿假单胞菌新的毒力因子。     

Circulating immune complexes, antibodies to Pseudomonas aeruginosa, and pulmonary status in cystic fibrosis

Serum samples from 37 patients with cystic fibrosis (CF), whose lungs were colonized by Pseudomonas aeruginosa, were tested in a 1 yr prospective study to examine a possible relationship between levels of circulating immune complexes (CIC) and the following parameters: level of specific antibodies to P. aeruginosa; relative importance of P. aeruginosa mucoid and non-mucoid strains isolated from sputum; the forced expiratory volume (FEV1; percentage predicted); the chest X-Ray score (Brasfield system) and the clinical score (Shwachman system). Reactivity of CIC against P. aeruginosa, Staphylococcus aureus, Haemophilus influenzae and Escherichia coli antigens were also assayed. We found that the FEV1, the chest X-Ray and the clinical scores were significantly lower in patients with high levels of CIC than in those with normal levels of CIC (p less than 0.001 for each). We also found that the level of IgG antibodies against P. aeruginosa was significantly higher (p less than 0.001) in patients with high levels of CIC than in those with normal levels of CIC. 78% of patients with high levels of CIC had predominantly mucoid P. aeruginosa isolates whereas only 21% of patients with normal levels of CIC had also predominantly mucoid P. aeruginosa isolates. Specific antibodies to P. aeruginosa were detected in all CIC isolated by polyethylene glycol precipitations from CF patients exhibiting both high levels of CIC and inferior pulmonary status. Our findings support the hypothesis that a high level of CIC in association with an aggressive humoral response to P. aeruginosa correlates with defective pulmonary status in cystic fibrosis.(ABSTRACT TRUNCATED AT 250 WORDS)     

Subinhibitory antibiotics reduce Pseudomonas aeruginosa tissue injury in the rat lung model

Using the agar-bead rat lung model, we evaluated the effects of subinhibitory antibiotic treatment upon Pseudomonas aeruginosa exoenzyme expression and lung injury in vivo. One hundred and twenty-eight animals were separated into two groups of 64 animals. One group was inoculated with P. aeruginosa DG1, and the other with P. aeruginosa 3740. Each of these two groups was divided into four subgroups of 16 animals on the basis of ten-day antibiotic treatment with ciprofloxacin, tobramycin and ceftazidime or untreated controls. P. aeruginosa DG1 is non-mucoid and expresses significant yields of exoenzyme S and elastase. P. aeruginosa 3740 is a mucoid organism isolated from the sputum of a cystic fibrosis patient, and demonstrates modest elastase activity only (10% of DG1 levels). Lung bacterial counts were similar in treatment and control groups. Lungs from antibiotic-treated rats demonstrated fewer histological changes than those from untreated animals (P less than 0.001). DG1 lung isolates from antibiotic-treated animals yielded less elastase and exoenzyme S compared with isolates from untreated animals (P less than 0.001). No detectable decrease in elastase or mucoid phenotype was observed in 3740 lung isolates from antibiotic treated animals. Thus, antibiotic protection against lung injury by P. aeruginosa may involve modulation of virulence factors.     

In vitro activity of the aerosolized agents colistin and tobramycin and five intravenous agents against Pseudomonas aeruginosa isolated from cystic fibrosis patients in southwestern Germany

Three hundred and eighty-five mucoid and non-mucoid strains of Pseudomonas aeruginosa isolated from 192 sputa from 57 adult cystic fibrosis patients were studied. Susceptibility testing using an agar dilution technique was performed for ceftazidime, ciprofloxacin, fosfomycin, meropenem and piperacillin, and the aerosolized agents colistin and tobramycin. Meropenem, ceftazidime and piperacillin were the most potent agents (susceptibility 86.2%, 84.2% and 84%, respectively). Tobramycin and colistin susceptibility rates were lower, but in light of higher intrabronchial concentrations of these drugs a greater percentage of strains might still be clinically susceptible. Only 46.2% and 41.8% of isolates were susceptible to ciprofloxacin and fosfomycin, respectively.     

Comparison of two commercial systems (Vitek and MicroScan-WalkAway) for antimicrobial susceptibility testing of Pseudomonas aeruginosa isolates from cystic fibrosis patients

Antimicrobial susceptibility testing of cystic fibrosis (CF) isolates of Pseudomonas aeruginosa is difficult because the organisms are often mucoid and slow-growing. This study of 498 CF strains examined the correlation of results derived from two commonly used commercial systems (Vitek, MicroScan-WalkAway) with a reference method for 10 antimicrobials. Correlation to reference results was unacceptably low for all agents and both commercial systems had a high rate of very major (false-susceptible) errors. Although mucoid strains produced a 4.8% greater intermethod error, it was not markedly different than non-mucoid strains for the Vitek System. Overall, these tested commercial systems performed poorly for CF isolates in contrast to earlier reported, high correlations with the reference methods (broth microdilution frozen panels and agar dilution) of the National Committee for Clinical Laboratory Standards, the standardized disk diffusion test, and the Etest (AB BIODISK, Solna, Sweden).