嗜麦芽窄食单胞菌医院感染及耐药性分析

目的：调查分析嗜麦芽窄食单胞菌的抗生素耐药情况。方法：对4年来我院住院患者标本中分离出的嗜麦芽窄食单胞菌,采用K—B法进行耐药性监测．并对感染患者进行回顾性调查。结果：40株嗜麦芽窄食单胞菌阳性标本中有36例为医院感染．对目前常用抗生素耐药性较高．尤其对肛内酰胺类抗生素。结论：嗜麦芽窄食单胞菌引起的感染应引起临床医生及检测人员的高度重视。     

肿瘤患者并发嗜麦芽窄食单胞菌感染

目的 了解医院内肿瘤患者感染嗜麦芽窄食单胞菌情况及其耐药性,以利于临床合理选用抗生素。方法 用法国生物梅里埃公司API 20 NE细菌鉴定试验条及ATB试验条进行菌种鉴定及药敏试验。结果 58株嗜麦芽窄食单胞菌中有42株（72.4%）分离自肿瘤患者呼吸道标本（痰34份,气管切口分泌物8份）;药敏试验显示其耐药率对环丙沙星最低（10.3%）,其次为头孢他定（13.8%）,再次为哌拉西林-他唑巴坦（41.4%）,对亚胺培南天然耐药。结论 嗜麦芽窄食单胞菌主要引起呼吸道感染,尤其是院内的肿瘤患者呼吸道特别易受感染：其多重耐药状况十分严重,对其感染的治疗,应在抗生素敏感试验的指导下进行.     

嗜麦芽窄食单胞菌血流感染的临床回顾性分析

目的 探讨嗜麦芽窄食单胞菌血流感染的临床特点、治疗方案和预后。方法 对浙江大学医学院附属第一医院2012年1月至2015年8月诊断为嗜麦芽窄食单胞菌血流感染的住院患者的临床资料进行回顾性分析。结果 54例嗜麦芽窄食单胞菌血流感染患者平均年龄50.5岁,检出前平均住院16天。17例（31%）合并有其他细菌感染,43例（80%）合并其他系统感染,其中合并肺部感染最常见（32例,占59.3%）。嗜麦芽窄食单胞菌血流感染多发生于恶性实体肿瘤、血液病患者（各占29.6%）,最常见于肝胆外科（25.9%）等科室。54例患者好转32例（59%）,死亡22例（41%）;好转组APACHEII评分（14.13±4.54）、死亡组APACHEII评分（27.59±8.17）,两组有统计学差异（P<0.05）。合并其他部位感染、高APACHEII评分组死亡率更高（P<0.05）,而使用敏感抗生素组死亡率更低（P<0.05）。结论嗜麦芽窄食单胞菌血流感染多见于免疫力低下的危重患者,多发生在院内外科手术操作的科室,并容易合并其他部位感染。规范使用敏感抗菌药物,积极治疗合并感染,可有助于改善嗜麦芽窄食单胞菌血流感染患者预后。     

嗜麦芽窄食单胞菌外排泵的研究进展

嗜麦芽窄食单胞菌为机会致病菌,是医院内感染的一个重要致病菌,据报道,该菌对临床使用的多数抗生素都有耐药性,耐β－内酰胺类,氨基糖苷类和大环内酯类药物,多重外排泵是嗜麦芽窄食单胞菌固有和获得性多重耐药的最重要原因,该菌参与抗生素和多种毒性物质外排的泵系统为SmeDEF和SmeABC。     

嗜麦芽窄食单胞菌耐药特性

为了解嗜麦芽窄食单胞菌 (Stenotrophomonasmaltophilia)的耐药特性 ,以指导临床用药 ,用微量肉汤稀释法进行药敏试验 ,用双纸片协同试验检测超广谱 β 内酰胺酶 (ESBLs)。结果显示 ,S .maltophilia对包括亚胺培南在内的三代、四代头孢和氨基糖苷类抗生素高度耐药 ,对左旋氧氟沙星、头孢哌酮 /舒巴坦、替卡西林 /克拉维酸、环丙沙星和复方新诺明耐药较低。有 5 2 % (2 6 /5 0 )的菌株产ESBLs,产酶菌对头孢哌酮 /舒巴坦耐药明显高于非产酶菌。可见 ,治疗S .maltophilia感染可首选左旋氧氟沙星、头孢哌酮 /舒巴坦、替卡西林 /克拉维酸或联合用药。产ESBLs的S .maltophilia可能作为传播ESBLs的一个潜在的传染源。     

嗜麦芽窄食单胞菌耐药机制研究进展

嗜麦芽窄食单胞菌是条件致病菌,主要感染医院内免疫力低下患者,所引起的医院感染日益增多。该菌属于多重耐药菌,对多种抗菌药物及一些消毒剂表现出抗药性。其耐药机制复杂,包括产生水解酶、外膜低渗透性、外排泵系统以及整合子、质粒、转座子等介导的可转移性耐药机制等。     

2004～2007年嗜麦芽窄食单胞菌临床分布和耐药性分析

较低,分别为0.6%、20.5%、26.5%和32.6%,对其他抗菌药物的耐药率均较高,其中对亚胺培南和美洛培南天然耐药.结论 嗜麦芽窄食单胞菌感染主要以下呼吸道为主,其临床分布主要为ICU 和呼吸内科, 嗜麦芽窄食单胞菌表现为高度和多重耐药性.对其引起的感染,可选用米诺环素、加替沙星、左氧氟沙星或复方磺胺进行经验治疗.     

113株嗜麦芽窄食单胞菌的临床分布及耐药性分析

目的了解绍兴市人民医院2010年1月到2011年6月嗜麦芽窄食单胞菌的临床分布情况及耐药性分析,为临床合理用药提供依据。方法从近年来该院各感染标本中分离出嗜麦芽窄食单胞菌,用法国梅里埃全自动微生物鉴定仪对细菌进行鉴定,并做临床常用抗生素耐药性分析,用WHONET 5.4软件进行统计学分析。结果 113株分离的嗜麦芽窄食单胞菌主要来自于ICU,标本主要来源于呼吸道感染的痰标本中;药敏结果显示,复方新诺明、米诺环素和左旋氧氟沙星等对嗜麦芽窄食单胞菌有较好的抗菌活性,敏感率依次为96.46%、96.46%和92.92%;对亚胺培南100%耐药;对氨苄西林/舒巴坦、美洛培南和氨曲南的耐药率依次为91.07%、90.27%和89.38%。结论该院临床分离的嗜麦芽窄食单胞菌主要来源于呼吸道感染患者的痰液标本中,以ICU患者感染居多,耐药现象比较严重,应加强耐药性监测,以指导临床合理用药,控制院内感染。     

2008-2010年嗜麦芽窄食单胞菌医院感染的临床分布及耐药性分析

目的了解医院感染嗜麦芽窄食单胞菌（Stenotrophomonasmaltophilia,Sm）的临床分布及耐药性情况,为临床诊治提供依据。方法采用回顾性资料,对中山大学附属第三医院2008—2010年间住院患者的各种临床标本中分离到的Sm及其药敏结果进行统计分析。结果Sm主要来源于呼吸道标本（痰及咽拭子）,占82．97％,临床分布以肝胆外科最多,占25．27％,其次为感染科（21．43％）,ICU和神经外科均占8．79％;40岁以上的中老年患者占75．82％;Sm对复方新诺明的敏感率最高,达84．40％,其次为左氧氟沙星（81．21％）,对头孢他啶和替卡西kS／克拉维酸的敏感性均较低（〈40％）。结论该院感染Sm的易感人群主要是以中老年患者为主,Sm对CLSI推荐的抗菌药物已有一定的耐药性,临床应高度重视,控制感染。     

2005年至2008年嗜麦芽窄食单胞菌的耐药性变迁

调查2005年至2008年嗜麦芽窄食单胞菌的耐药情况,为临床有效治疗嗜麦芽窄食单胞菌感染提供依据。从各类标本中分离出嗜麦芽窄食单胞菌株并利用API系统鉴定。采用Kirby-Bauer法和微量肉汤稀释法进行药敏试验。2005年至2008年共分离出嗜麦芽窄食单胞菌株337株。嗜麦芽窄食单胞菌对碳氢酶烯类药物、氨基糖苷类、三代头孢菌素、氨曲南和β-内酰胺酶抑制剂复方制剂高度耐药,复方新诺明和米诺环素对嗜麦芽窄食单胞菌的敏感率在90%以上。嗜麦芽窄食单胞菌对临床上常用的大多数抗菌药物高度耐药,可首选复方新诺明和米诺环素治疗嗜麦芽窄食单胞菌感染。     

Intra-hospital dissemination of clinical and environmental isolates of Stenotrophomonas maltophilia from Tehran

Stenotrophomonas maltophilia isolates are responsible for various hospital-acquired infections and are particularly increasing in the immunocompromised patients. The aim of this study was to determine the clonal relatedness between S. maltophilia isolates originating from the clinic and environment. A total of 150 S. maltophilia isolates from patients and 1108 environmental samples obtained in three hospitals from Tehran. Following molecular identification targeting 23S rRNA gene, the clonal relatedness of the environmental and clinical isolates was determined using pulsed field gel electrophoresis (PFGE). Of the 150 clinical and 18 environmental isolates identified using phenotypic tests, the speciation of 120 and 15 was confirmed by targeting the 23S rRNA gene. The 24 common pulsotypes (PTs) and 32 single PTs were identified by PFGE. Only a small cluster was shared among the clinic and environment within a hospital; therefore, the intra-hospital dissemination of certain isolates of S. maltophilia among the clinic and environment was demonstrated.     

D-Aminoacylase from a novel producer: Stenotrophomonas maltophilia ITV-0595

A novel bacterial strain producing D-aminoacylase was isolated from organic waste and identified as Stenotrophomonas maltophilia ITV-0595. The isolation was performed using N-acetyl-D-phenylglycine (NAcDPG) as the sole source of C and N. The optimum pH for enzyme expression was 8 at 37°C. Using N-Ac-DPG concentrations from 0.5 up to 3% w/v, it was observed that at the 1% level, the microorganism showed acceptable responses in both enzyme activities and cell growth. From the different tested compounds N-acetyl-D-methionine (1%) was the best enzyme inducer (Sp. act. = 4.14 U mg⁻¹ protein, Vol. act. = 0.17 U ml⁻¹) and the only one that increased cell growth. Received 13 June 1997/ Accepted in revised form 29 October 1998     

Identification of Stenotrophomonas maltophilia strains isolated from environmental and clinical samples: a rapid and efficient procedure

Aims: Aim of the study is to identify accurately Stenotrophomonas maltophilia isolates recovered from environmental and clinical samples. Methods and Results: Recovery of Sten. maltophilia‐like isolates from soil samples using the vancomycin, imipenem, amphotericin B (VIA) selective agar medium enabled distinction of various morphotype colonies. A set of soil and clinical isolates was tested for species identification using different methods. 16S rDNA analyses showed the dark green with a blue halo morphotype to be typical Sten. maltophilia strains. The API‐20NE, Vitek‐2 and Biolog phenotypic analyses typically used for the identification of clinical isolates did not perform well on these soil isolates. The species‐specific PCR screening targeting Sten. maltophilia 23S rDNA and the multiplex smeD/ggpS PCR, differentiating Sten. maltophilia from Stenotrophomonas rhizophila, were tested for improvement of these identification schemes. The latter multiplex PCR identified all isolates tested in this study, whatever be their origin. Conclusions: Isolation on VIA medium and confirmation of Sten. maltophilia species membership by smeD PCR is proposed to identify environmental and clinical isolates of Sten. maltophilia. Significance and Impact of the Study: The proposed approach enables isolation and identification of Sten. maltophilia from different environments in an easy and rapid way. This approach will be useful to accurately manage studies on the abundance and distribution of Sten. maltophilia in hospital and nonhospital environments.     

Cytotoxic activity of clinical Stenotrophomonas maltophilia

AIMS: To determine the potential virulence factors produced by culture supernatants of clinical isolates of Stenotrophomonas maltophilia. METHODS AND RESULTS: Culture supernatants of clinical isolates of S. maltophilia were assayed for haemolytic, enzymatic (lipase, protease and phospholipase) and cytotoxic activity. Cytotoxic activity was assayed in Vero (African green monkey), HeLa (human cervix) and HEp-2 (human larynx epidermoid carcinoma) cells. Microscopic analyses revealed intensive rounding, loss of intercellular junctions and membrane alterations (blebbing) followed by death of HEp-2 cells. In Vero and HeLa cells, the cytotoxic effects were characterized by vigorous endocytosis and cell aggregation. The viability of cultured mammalian cells was determined with neutral red and demonstrated that the sensitivity among the cells was different. This activity was inactivated by heating at 56 degrees C for 15 min and protease inhibitors did not inhibit cytotoxic activity. The clinical S. maltophilia presented a cell-free haemolytic activity similar to the 'hot-cold' haemolysins. CONCLUSIONS: S. maltophilia culture supernatants caused vigorous endocytosis and cell aggregation in HeLa and Vero cells, produced haemolytic and enzymatic activities. SIGNIFICANCE AND IMPACT OF THE STUDY: This work revealed the presence of putative virulence factors that could be associated with human infections involving Stenotrophomonas maltophilia strains.     

下呼吸道标本中嗜麦芽窄食单胞菌临床分离株耐药性分析

目的探讨嗜麦芽窄食单胞菌的耐药情况,为临床医师在按指南和结合临床选择抗菌药物时提供药敏监测资料。方法对我院2001年1月～2007年1月间从我院住院患者下呼吸道标本中分离的嗜麦芽窄食单胞菌临床菌株进行药物敏感性分析。结果2001年1月～2007年1月从我院住院患者下呼吸道标本中共分离出嗜麦芽窄食单胞菌133株。其中,60.2%(80/133)来源于咳痰标本,41株(30.8%)从经气管插管吸引物中分离得到。青霉素类对嗜麦芽窄食单胞菌抗菌活性较差;头孢菌素类药物中,以头孢吡肟的抗菌活性最强,敏感率达88.0%;嗜麦芽窄食单胞菌对各种氨基糖苷类药物的敏感性水平较为接近;氟喹诺酮类药物中,环丙沙星和左旋氧氟沙星敏感度较高,分别为52.6%和63.9%;嗜麦芽窄食单胞菌对亚胺培南耐药性高达91.0%;复方磺胺甲(口恶)唑对嗜麦芽窄食单胞菌具有较强的抗菌活性,敏感度为92.5%。结论下呼吸道标本中嗜麦芽窄食单胞菌对各种药物的耐药性较高,临床医师须参考实验室检验结果及药物敏感试验选择合理的抗菌药物治疗,提高疗效,避免耐药菌的进一步产生。     

1株高产蛋白酶嗜麦芽寡养单胞菌的分离鉴定及其酶学活性的研究

双齿围沙蚕消化道中分离1株高产蛋白酶菌株D2(CGMCC保藏号:1868),经形态学、生理学、16S rRNA基因序列测定及系统发育分析确定为嗜麦芽寡养单胞菌。Lowry法检测显示该菌株产酶能力为1104 U/mL,最佳产酶条件为pH 8.0、25℃培养48 h;酪蛋白酶图谱法和凝胶成像分析证实其蛋白酶分子量约为42 ku,在培养上清液中纯度大于97%;该酶对粗酶品比活性为301 U/mg,酶活性的最适pH值为9,是一种碱性蛋白酶;最适温度为60℃;在55℃以下及pH 6~10的环境中具有较好的稳定性。嗜麦芽寡养单胞菌D2株有望成为一种新的蛋白酶生产资源。     

Comparison of pulsed‐field gel electrophoresis and three rep‐PCR methods for evaluating the genetic relatedness of Stenotrophomonas maltophilia isolates

Aims: In this study, three facile repetitive‐sequence PCR (rep‐PCR) techniques have been compared with the pulsed‐field gel electrophoresis (PFGE) method for differentiating the genetic relatedness of clinical Stenotrophomonas maltophilia isolates. Methods and Results: The dendrograms of 20 S. maltophilia isolates were constructed based on the data obtained from PFGE and three PCR‐based methods, i.e. enterobacterial repetitive intergenic consensus‐PCR (ERIC‐PCR), BOX‐PCR and repetitive extragenic palindromic‐PCR (REP‐PCR). When compared with PFGE, ERIC‐PCR displayed a much lower discriminatory power, whereas BOX‐PCR and REP‐PCR had a comparable discriminatory power for close genetic‐related isolates. Conclusion: BOX‐PCR and REP‐PCR can be convenient and effective methods for evaluating the close genetic relatedness of clinical S. maltophilia isolates. Significance and Impact of the Study: A rapid method for determining S. maltophilia’s close genetic relatedness provides a convenient tool for understanding the epidemiology of S. maltophilia.