大肠埃希菌、克雷伯菌产超广谱β-内酰胺酶的检测及耐药性分析

目的研究本院3年中大肠埃希菌、克雷伯菌ESBLs的检出率及对常用抗生素的耐药情况。方法对山西医科大学第二医院2001～2003年分离的837株大肠埃希菌、216株克雷伯菌用标准纸片扩散确证法检测其ESBLs产生率；采用K-B法进行药敏检测。结果大肠埃希菌产ESBLs分离率为2001、2002、2003分别为12．27％、15．90％、30，85％；克雷伯菌产ESBLs分离率为2001、2002、2003分别为23．88％、28．81％、30．00％；产ESBLs株对头孢菌素类、氨基糖苷类、氟喹喏酮类耐药率均高于非产ESBLs菌株；未发现对亚胺培南耐药的菌株。结论近年来大肠埃希菌、克雷伯菌产ESBLs菌株逐年升高，应引起足够的重视，采取有效措施控制产ESBLs菌的感染。     

大肠埃希菌感染的临床分布与耐药性

目的调查医院大肠埃希菌感染的临床分布及耐药,为临床合理使用抗菌药物提供科学依据.方法对358株临床分离的大肠埃希菌对药物敏感试验结果进行回顾性分析.结果大肠埃希菌感染的部位主要见于伤口、泌尿道、呼吸道、血液、引流液等;大肠埃希菌耐药率低的抗菌药物是亚胺培南、阿米卡星、哌拉西林/他唑巴坦,耐药率<10%;对氟喹诺酮类及头孢菌素耐药率较高.结论治疗大肠埃希菌感染时,需根据药敏结果及患者病情选用碳青酶烯类、氨基糖苷类、β-内酰胺类抗生素/β-内酰胺酶抑制剂等.     

上海市2016-2022年腹泻病例致泻性大肠埃希菌感染的流行特征与耐药分析

目的 掌握上海市腹泻病例致泻性大肠埃希菌（DEC）的感染情况、流行病学特征及耐药情况,为后续监测和防控提供数据支撑。方法 基于上海市腹泻病综合监测系统收集2016-2022年肠道腹泻门诊病例的流行病学资料,采集粪便标本,开展DEC检测。基于国家致病菌识别网系统收集2016-2022年药敏监测数据。统计学分析采用χ²检验或Fisher确切概率法。结果 在24 883例感染性腹泻患者中,DEC阳性率为9.13%（2 271/24 883）,其中单一致病型DEC阳性率为8.83%（2 197/24 883）,混合致病型DEC阳性率为0.30%（74/24 883）。DEC阳性主要型别为肠产毒性大肠埃希菌［4.33%（1 077/24 883）］,以≤5岁组人群的DEC阳性率最高［18.48%（22/119）］。2016-2022年DEC阳性率最高月份为7-9月［5.91%（1 470/24 883）］。2016-2022年市区和郊区的DEC阳性率分别为9.47%（554/5 847）和9.02%（1 717/19 036）,市区和郊区的DEC主要型别分别为肠黏附性大肠埃希菌［3.98%（233/5 847）］和肠产毒性大肠埃希菌［4.56%（868/19 036）］。2016-2019和2020-2022年DEC阳性率分别为9.42%（1 821/19 330）和8.10%（450/5 553）,主要型别分别为肠产毒性大肠埃希菌（4.87%,941/19 330）和肠黏附性大肠埃希菌（4.70%,261/5 553）。耐药菌株的多重耐药率为40.21%（618/1 537）。耐药率较高的前三位药物依次为氨苄西林［64.74%（995/1 537）］、萘啶酸［58.49%（899/1 537）］和四环素［45.09%（693/1 537）］。结论 相比于2016-2019年,2020-2022年DEC阳性率下降,主要型别由肠产毒性大肠埃希菌转变为肠黏附性大肠埃希菌。多重耐药现象较严重,建议应加强DEC的耐药性持续监测,同时规范临床抗生素的使用。     

Anterior Cervical Discectomy and Fusion Using Escherichia coli-Derived Recombinant Human Bone Morphogenetic Protein-2: A Pilot Study

BackgroundRecombinant human bone morphogenetic protein-2 (BMP-2) is an osteoinductive growth factor widely used in orthopedic surgery; it is also known to be associated with postoperative airway compromise or dysphagia when applied to anterior cervical discectomy and fusion (ACDF). However, there have been no reports on ACDF using Escherichia coli-derived BMP-2 (E.BMP-2) with hydroxyapatite (HA). This pilot study aimed to investigate the potential efficacy and safety of E.BMP-2 using HA as a carrier in ACDF prior to designing a larger-scale prospective study.MethodsPatients eligible for inclusion were those who underwent ACDF using 0.3 mg of E.BMP-2 with HA per segment for degenerative cervical disc disease between August 2019 and July 2020 and had at least 1 year of follow-up. Fusion rates were analyzed using computed tomography or flexion-extension radiographs. Visual analog scales for neck pain and arm pain and neck disability index were measured preoperatively and the final follow-up. In cases of cervical spondylotic myelopathy, modified Japanese Orthopaedic Association scores were also evaluated. Postoperative complications such as airway compromise, dysphagia, wound infection, neurologic deficit, hoarseness, heterotopic ossification, seroma, and malignancy were investigated.ResultsA total of 11 patients and 21 segments were analyzed. All clinical outcomes significantly improved at the final follow-up compared with the preoperative indices (p < 0.05). Only 1 case of dysphagia and no cases of airway compromise, wound infection, neurologic deficit, hoarseness, heterotopic ossification, seroma, or malignancy were observed during the follow-up period. Of the 21 segments, 15 segments showed solid fusion at 3 months after surgery, 4 segments at 6 months, and 1 segment at 12 months. Only 1 segment showed pseudoarthrosis, resulting in a fusion rate of 95.2%.ConclusionsThe outcomes of ACDF could be enhanced using 0.3 mg of E.BMP-2 with HA per segment. Based on this study, larger-scale prospective studies can be conducted to evaluate the efficacy and safety of E.BMP-2 in ACDF.     

重组蛋白在大肠杆菌分泌表达的研究进展

长期以来,大肠杆菌是表达外源蛋白的首选表达系统,重组蛋白分泌表达与胞内表达相比有很大优越性,在细胞周质腔不仅能促进重组蛋白二硫键的形成及正确折叠,还能促进分泌蛋白的N-端加工。本文综述了近年来在大肠杆菌中表达可溶性外源蛋白的进展,目的是为了提高外源蛋白的生物活性。     

2019—2021年天津市宝坻区人民医院住院患者多重耐药菌检出及耐药分析

目的 探讨2019—2021年天津市宝坻区人民医院住院患者多重耐药菌（MDRO）检出及耐药分析,为临床抗菌药物的合理应用提供依据。方法 收集2019年1月—2021年12月天津市宝坻区人民医院住院患者送检标本分离的MDRO,排除同一患者同一部位分离的重复菌株。采用法国生物梅里埃公司VITEK-2 Compact型全自动微生物鉴定与药敏分析仪进行病原菌鉴定和药敏试验。对临床使用的3类或3类以上抗菌药物同时呈现耐药的细菌定义为MDRO并进行耐药分析。结果检出多重耐药菌1 083株,其中产超广谱β-内酰胺酶（ESBLs）大肠埃希菌645株（59.56%）、产ESBLs肺炎克雷伯菌144株（13.3%）、多重耐药鲍曼不动杆菌（MDRAB）140株（12.93%）、耐甲氧西林金黄色葡萄球菌（MRSA）79株（7.29%）、多重耐药铜绿假单胞菌（MDRPA）54株（4.99%）、耐碳青霉烯的肠杆菌（CRE）21株（1.94%）。2019—2021年,MDRAB、MDRPA和CRE的检出率比较差异有统计学意义（P<0.05）;组间比较,MDRAB的检出率2021年高于2020年（P<0....     

羧甲基壳聚糖复合纳米银、纳米氧化铜的制备及抑菌性研究

本研究在水热条件下利用羧甲基壳聚糖分别还原硝酸银和硫酸铜,得到稳定的羧甲基壳聚糖复合纳米银和纳米氧化铜,并测试其抑菌能力.表征测试显示,所制的纳米银为20～30 nm的球状结构,纳米氧化铜为80～100 nm的花瓣状结构,二者都均匀稳定地分布于羧甲基壳聚糖中.抑菌试验显示,不同浓度的羧甲基壳聚糖复合纳米银(A组2 mg...     

A Bacterial DNA Repair Test Evaluating the Genotoxicity of Light Sources

A DNA repair test was used in order to assess its applicability for detecting the genotoxicity of sunlight and of the light emitted by halogen lamps and fluorescent lamps. This experimental system compares the lethality of test agents in the Escherichia coli wild-type WP2 and its isogenic counterparts lacking, either individually or in combination, various DNA repair mechanisms. DNA repair-deficient strains included WP2uvrA (uvrA^-), WP67 (uvrA^- polA^-), CM561 (lexA^-), CM571 (recA^-), WP100 (uvrA^- recA^-), and CM871 (uvrA^- recA^- lexA^-). All light sources produced a substantial killing of repair-deficient strains, with a maximum activity in the triple mutant CM871, at doses that did not affect survival of the wild type. The genotoxicity of uncovered quartz halogen bulbs was particularly potent, compared to fluorescent lamps and sunlight. Moreover, the mechanisms involved in repairing the DNA damage induced by halogen lamps were similar to those of a 254 nm UV source. The spectrum of genetic damage produced by sunlight and fluorescent lamps was conversely more comparable to that of a 365 nm UV source. These data demonstrated a harmful emission of appreciable amounts of genotoxic far-UV wavelengths by halogen lamps, thereby confirming our previous results in the his^-Salmonella typhimurium mutagenicity test. Genotoxicity of halogen lamps could be easily prevented in both experimental systems by suitable glass or plastic covers. Compared to the mutagenicity end point, the differential lethality end point provided even more clear-cut results in detecting the DNA-damaging ability of all light sources. Moreover, parallel assays provided evidence that the bacterial DNA repair test was far more sensitive than the mutagenicity test in evaluating the genotoxicity of the light produced by halogen lamps. On the whole, the DNA repair test in E. coli is even simpler and faster (24 vs. 48 h) than the Salmonella mutagenicity test, and compares favorably in terms of sensitivity to genotoxic light sources.