嗜麦芽寡养单胞菌临床株外排泵SmeDEF诱导表达的研究

目的了解嗜麦芽寡养单胞菌的临床株H407和A26在抗菌药物诱导下耐药性和SmeDEF外排泵表达的变化。方法比较有或无环丙沙星诱导时嗜麦芽寡养单胞菌H407和A26的MIC和EOP值,对在亚抑菌浓度环丙沙星中培育后的菌株smeD基因进行RT-PCR扩增,监测表达水平。结果对抗生素敏感的H407和A26泵抑制呈阳性或阴性反应。2株菌经环丙沙星过夜孵育后测得的对氯霉素和环丙沙星MIC值比正常非诱导时的MIC值高1~3个稀释度;加泵抑制剂CCCP后,2个诱导株的MIC值均有明显下降。H407和A26经环丙沙星诱导后氯霉素的EOP分别有4.8和近4倍的增长。2株菌在抗菌药物过夜和指数期添加生长时smeD的mRNA明显高于无抗菌药物培养株。结论2株嗜麦芽寡养单胞菌临床株在环丙沙星诱导下对部分抗菌药物的耐药性提高,与SmeDEF泵的诱导表达增加有关。     

Identification of Pseudomonas aeruginosa, Burkholderia cepacia complex, and Stenotrophomonas maltophilia in respiratory samples from cystic fibrosis patients using multiplex PCR

A multiplex PCR method was developed to identify P. aeruginosa, B. cepacia complex, and S. maltophilia directly in sputum and oropharyngeal samples from CF patients. One hundred and six patients (53 male, and 53 female) attending our pulmonology clinic were studied from September 2000-April 2001. Two hundred and fifty-seven samples were cultured in selective media and submitted to multiplex PCR reactions, using three primer pairs targeting specific genomic sequences of each species, with an additional primer pair targeting a stretch of ribosomal 16S DNA, universal for bacteria, to act as a control. P. aeruginosa was isolated by culture in 56% of samples, B. cepacia complex in 4.3%, and S. maltophilia in 2.7%, while multiplex PCR identified P. aeruginosa in 78.7%, B. cepacia complex in 3.9%, and S. maltophilia in 3.1% of samples. Multiplex PCR results were verified by PCR reactions using different species-specific primers described in the literature and DNA sequencing of amplicons from a few samples. Comparing to culture results, the sensitivity and specificity values of multiplex PCR for bacterial identification were, respectively, 97.2% and 45.5% for P. aeruginosa, 45.5% and 97.9% for B. cepacia complex, and 40% and 97.6% for S. maltophilia. All 10 multiplex PCR-positive results for B. cepacia complex were confirmed using other species-specific primers described in the literature, while this approach confirmed results for S. maltophilia identification in 7/8 samples (87.5%). Sequencing of amplicons from samples culture-negative but multiplex PCR-positive for P. aeruginosa and B. cepacia complex confirmed their identity, while minor nucleotide differences among amplicons ruled out the hypothesis of PCR contamination.     

重症监护病房嗜麦芽寡养单胞菌暴发流行调查

目的对重症监护病房嗜麦芽寡养单胞菌暴发感染进行流行病学调查分析,为预防与控制医院感染提供参考资料。方法对2006年2月5-16日的4例医院感染嗜麦芽寡养单胞菌的患者进行流行病学调查分析。结果4例嗜麦芽寡养单胞菌感染病例有2种耐药菌谱;在床护栏、2台呼吸机呼气阀组件的集水瓶接头处和雾化液中检出了嗜麦芽寡养单胞菌。结论此次嗜麦芽寡养单胞菌感染为局部暴发流行;呼吸机消毒不严格和医疗环境的污染是造成此次感染的主要因素,一旦发现病房有局部暴发流行应停止接收患者,对病房进行严格消毒。     

医院感染嗜麦芽窄食单胞菌危险因素的Meta分析

目的 系统评价医院感染嗜麦芽窄食单胞菌（SMA）的危险因素。方法 检索PubMed、Embase、Cochrane Library、中国期刊全文数据库（CNKI）、中国生物医学文献数据库（CBM）、万方数据库以及维普数据库（VIP）中建库至2019年3月发表的有关医院感染SMA危险因素的研究文献，2名研究员独立按照纳入与排除标准筛选文献、提取资料及质量评价后，采用RevMan 5.3软件进行Meta分析。结果 共纳入10篇文献，3篇为英文，7篇为中文。Meta分析结果显示，入院时APCHE-II评分>20分（OR=3.69，95%CI：1.58~8.59）、ICU时间> 7 d （OR=2.14，95%CI：1.55~2.95）、住院时间（MD=7.54，95%CI：6.22~8.86）、使用糖皮质激素（OR=2.40，95%CI：1.57~3.68）、合并免疫功能缺陷性疾病（OR=2.31，95%CI：1.64~3.25）、机械通气（OR=7.59，95%CI：3.40~11.97）、气管插管（OR=4.98，95%CI：3.21~7.73）、气管切开（OR=4.31，95%CI：2.80~6.64）、中心静脉置管（OR=1.68，95%CI：1.19~2.38）、留置鼻胃管（OR=3.10，95%CI：1.83~5.26）、使用碳青霉烯类（OR=2.81，95%CI：2.24~3.54）、使用β-内酰胺酶抑制剂（OR=3.52，95%CI：1.71~7.24）、使用氨基糖苷类（OR=1.93，95%CI：1.37~2.73）、使用糖肽类（OR=3.42，95%CI：1.13~10.32）和使用抗菌药物≥3种（OR=2.70，95%CI：1.75~4.16）是医院感染SMA的危险因素（均P<0.05）。结论 医院感染SMA的危险因素较多，临床应采取针对性预防措施，以降低其感染风险。     

皖南地区74例嗜麦芽窄食单胞菌的分布及耐药分析

目的了解皖南地区嗜麦芽窄食单胞菌的分布情况及耐药性,为临床治疗提供参考。方法对皖南地区2007～2009年检测出的嗜麦芽窄食单胞菌进行回顾性分析。结果患者年龄分布以60岁以上为主,感染部位以肺部为主,感染科室以干部内科为主;74例标本药敏结果耐药率从高到低依次为头孢噻肟87.83%、头孢吡肟64.87%、头孢他啶52.70%、替卡西林/克拉维酸41.89%、氯霉素24.32%、头孢哌酮/舒巴坦21.62%、复方新诺明21.62%、左旋氧氟沙星14.86%、米诺环素13.51%。结论作为条件致病菌,嗜麦芽窄食单胞菌的感染已呈增加趋势,应引起临床足够重视,药物治疗应首选四环素类、喹诺酮类和磺胺类。     

新生儿重症监护病房嗜麦芽窄食单胞菌感染临床分析

目的探讨新生儿重症监护病房（NICU）嗜麦芽窄食单胞菌（SMA）感染的临床特点、耐药情况及治疗。方法对2008年1月至2012年12月我院NICU收治的SMA感染患儿进行回顾性分析,对其临床特征、细菌耐药性及治疗情况进行总结。结果本院NICU近5年共收治新生儿20463例,其中SMA感染54例,发生率2.63‰,2008—2012年发生率分别为4.17‰、2.80‰、3.05‰、2.50‰、0.94‰。其中新生儿败血症36例,新生儿肺炎18例;早产儿与足月儿发生率差异无统计学意义（2.61‰比2.65‰,P〉0.05）。临床主要表现为气促（27例）、黄疸（22例）、青紫（17例）、消化道出血（7例）、腹胀（8例）、呕吐（7例）等,常见并发症有呼吸衰竭（18例）、心力衰竭（13例）、坏死性小肠结肠炎（6例）、弥散性血管内凝血（4例）、休克（3例）等;13例（24.1%）考虑为医院感染,早产儿及气管插管机械通气患儿医院感染发生率分别高于足月儿及鼻塞无创辅助通气患儿（1.63‰比0.2‰,7.21‰比0.75‰,P均〈0.01）。SMA对头孢哌酮/舒巴坦、替卡西林/克拉维酸钾敏感度较高,均〉70%,对哌拉西林/他唑巴坦、头孢他啶耐药率在30%~40%。结论SMA是新生儿医院感染的重要病原菌,新生儿SMA感染主要表现为新生儿败血症和新生儿肺炎,耐药率高,早产儿医院感染SMA发生率高于足月儿。     

Antimicrobial susceptibility pattern of Stenotrophomonas species isolated from Mexico

BackgroundStenotrophomonas species are multi-resistant bacteria with ability to cause opportunistic infectionsObjectiveWe isolated 45 Stenotrophomonas species from soil, sewage and the clinic with the aim of investigating their susceptibility to commonly used antimicrobial agents.MethodologyThe identities of isolates were confirmed with 16S rRNA gene sequence and MALDI-TOF analysis. Anti-microbial resistance, biofilm production and clonal diversity were also evaluated. The minimum inhibitory concentration technique as described by Clinical & Laboratory Standards Institute: CLSI Guidelines (CLSI) was employed for the evaluation of isolate susceptibility to antibiotics.ResultForty-five Stenotrophomonas species which include 36 environmental strains and 9 clinical strains of S. maltophilia were considered in this study. 32 (88.9 %) environmental strains were identified to be S. maltophilia, 2 (5.6 %) were Stenotrophomonas nitritireducens, and 2 (5.6 %) cluster as Stenotrophomonas spp. Stenotrophomonas isolates were resistant to at least six of the antibiotics tested, including Trimethoprim/Sulfamethoxazole (SXT).ConclusionEnvironmental isolates from this study were resistant to SXT which is commonly used for the treatment of S. maltophilia infections. This informs the need for good public hygiene as the environment could be a reservoir of multi-resistant bacteria. It also buttresses the importance of surveillance study in the management of bacterial resistance.     

Unilateral conjunctival ulcer due to Stenotrophomonas maltophilia infection

We report a case of unilateral conjunctival ulcer due to Stenotrophomonas maltophilia infection in an immunocompetent individual. A 44-year-old male presented with complaints of pain and yellowish discharge in the right eye for one week. Patient underwent complete ophthalmic evaluation and relevant laboratory investigations. Anterior segment examination revealed localized conjunctival and episcleral congestion with conjunctival ulceration on the bulbar conjunctiva in the right eye. Gram's stain revealed gram-negative bacilli. Culture and sensitivity revealed S. maltophilia and responded well to topical moxifloxacin with systemic co-trimoxazole therapy.     

嗜麦芽寡养单胞菌肺部感染的耐药性分析

目的探讨肺部感染嗜麦芽寡养单胞菌的危险因素和耐药情况。方法回顾分析医院2007年7月至2011年7月检出的345株嗜麦芽寡养单胞菌,采用纸片扩散法得出的药敏结果资料。结果 345株嗜麦芽寡养单胞菌药物敏感实验结果显示,该菌对磺胺甲噁唑/甲氧苄啶耐药率最低为14.7%,而对亚胺培南耐药率最高为100%。结论应加强对嗜麦芽寡养单胞菌耐药性检测,根据药敏试验结果合理选用抗菌药物。     

Stenotrophomonas maltophilia Pseudo-outbreak at a University Hospital Bronchoscopy Unit in Turkey

Objective:

Stenotrophomonas maltophilia is an opportunistic pathogen found predominantly in the enviroment and hospital setting. Invasive procedures and treatment methods, instruments used for diagnosis and irrational antibiotic use play major roles in the spread of this pathogen. The study aimed to evaluate consecutive S maltophilia isolation from bronchoalveolar lavage samples during bronchoscopy procedure during a week.

Methods:

Four patients consecutively had S maltophilia isolated during bronchoscopy between September 8 and 15, 2012. The identification of the isolates and their antibiotic susceptibility were studied by automated Vitek version 2.0 (Biomerieux, France) system. The clonal relationship between the isolates was studied by enterobacterial repetitive intergenic consensus (ERIC) polymerase chain reaction (PCR).

Results:

Four consecutive S maltophilia isolates had identical band patterns and showed clonal relatedness.

Conclusion:

Bronchoscopy is a common invasive procedure that is utilized in chest diseases departments and intensive care units (ICUs). Contamination may take place due to inappropiate use and cause spread of infectious pathogens. In the current study, we detected consecutive S maltophilia strains with identical band patterns isolated within a week. After appropiate disinfection and cleaning procedures, no further isolation was detected.