Immune Reconstitution Inflammatory Syndrome Secondary to Mycobacterium kansasii Infection in a Kidney Transplant Recipient

Nontuberculous mycobacteria (NTM) infection is a challenging diagnosis for clinicians in solid organ transplantation. Immune reconstitution inflammatory syndrome (IRIS) is so far unreported in this context. We report here the case of a renal transplant recipient who developed Mycobacterium kansasii–associated lymphadenitis complicated by IRIS while undergoing reduction of his immunosuppressive therapy. For IRIS, the patient required low‐dose steroids and an increase in global immunosuppression, in association with NTM antibiotherapy.     

抗菌肽P9-0对口腔感染细菌作用机制的初步探讨

目的测定抗菌肽P9-0对2种口腔感染常见细菌的抑菌活性,初探其抗菌机制。方法选取口腔感染常见细菌金黄色葡萄球菌和具核梭杆菌,测定抗菌肽P9-0对2种细菌的最低抑菌浓度,通过扫描电子显微镜、荧光显微镜观其形貌。结果抗菌肽P9-0对2种细菌最低抑菌浓度均为50μg·m L-1。扫描电子显微镜和荧光显微镜观察显示药物处理后,细菌胞膜在形态学和完整性上发生明显变化。结论抗菌肽P9-0可抑制口腔感染常见之细菌金黄色葡萄球菌和具核梭杆菌,抗菌机制可能是通过胞膜破坏作用。     

Differential transformation and antibacterial effects of silver nanoparticles in aerobic and anaerobic environment

Silver nanoparticles (AgNP) undergo various transformations into different Ag species in the environment, which determines their toxicity in microorganisms. In aerobic condition, AgNPs release Ag⁺ that causes cell inactivation. Limited information is known about the AgNP-cell interaction in oxygen-free environment. Here we compared the transformation and antibacterial effects of AgNPs in aerobic and anaerobic environment. The bacterium Pseudomonas aeruginosa was relatively not susceptible to Ag⁺ or AgNP in anaerobic environment, indicated by near two orders of magnitude greater of anaerobic minimum inhibitory concentration (MIC) than the aerobic counterpart. In anaerobic environment, the dissolved Ag concentration decreased due to the reduction of Ag⁺. Electron microscopy images showed the formation of new AgNPs and aggregates, preferably on cell surface or associated with extracellular polymer substances (EPS) matrix. Accumulating AgNPs onto the cells could cause membrane damage, cytoplasm release or bacterial death. Meanwhile, EPS and cell lysate were very likely to bind AgNPs, facilitating the extensively assembling of AgNPs into large aggregates. This reduced the effective Ag exposure to cells and might contribute to the detoxification in anaerobic environment. Further, flow cytometry analysis quantified that bacterial membrane was largely intact under the treatment of AgNPs in anaerobic condition compared to the dose–response manner in aerobic condition.     

铜绿假单胞菌褐藻胶合成抑制剂筛选模型的建立

目的 建立以铜绿假单胞菌（Pseudomonas aeruginosa）乙酰化褐藻胶的合成为靶向的筛选模型,用于筛选抑制铜绿假单胞菌褐藻胶合成的活性分子。 方法 分别建立铜绿假单胞菌双层平板筛选模型和PalgD-GFP 荧光分子模型,从海洋微生物代谢产物中筛选抑制铜绿假单胞菌乙酰化褐藻胶合成的活性分子。 结果 利用2个筛选模型筛选300余种化合物,获得2种抑制铜绿假单胞菌合成褐藻胶的化合物,且化合物的抑制作用具有浓度依赖性,验证了模型的可行性和有效性。 结论 2种模型结合,可以高效、准确地筛选目标化合物,为解决细菌耐药问题提供了1种有效的手段。     

Synthesis,characterization, and antimicrobial activity of some new N‐aryl‐N’‐(2‐oxoindolin‐3‐ylidene)‐benzohydrazonamides

A green approach was developed for synthesizing a series of (isatin‐3‐ylidene)‐hydrazonamides 3a–j  from the reaction between isatin, (isatin‐3‐ylidene)malononitrile, or 2‐cyano‐2‐(2‐isatin‐3‐ylidene)acetate and benzohydrazonamide in ethyl acetate solutions at ambient temperature. The structures of the new compounds were confirmed on the basis of spectral data. In this eco‐friendly medium, a variety of (isatin‐3‐ylidene)hydrazonamides were obtained free of catalyst in good to excellent yields. All the synthesized products were evaluated for their antimicrobial activity. Among the compounds tested, 3b and 3d exhibited good antibacterial activity against Staphylococcus aureus, whereas others responded moderately with reference to the standard drug ciprofloxacin.     

2016-2018年清镇市第一人民医院铜绿假单胞菌的分布及耐药性分析

目的 探讨2016-2018年清镇市第一人民医院铜绿假单胞菌感染的临床分布特征及耐药性变迁,为临床合理选用抗生素治疗提供参考。方法 收集2016-2018年清镇市第一人民医院临床标本中铜绿假单胞菌的检出情况、病区分布、标本来源及药敏结果等资料,并进行统计分析。结果 共分离出铜绿假单胞菌215株,以痰液标本来源为主,占84.2%,感染病区以呼吸内科、ICU和神经外科占前3位,分别占33.9%、18.1%、17.7%。铜绿假单胞菌对复方新诺明、氨苄西林、头孢唑林、氨苄西林/舒巴坦和头孢曲松的耐药率在90.0%以上,对阿米卡星的耐药率最低。与2016年相比较,2018年铜绿假单胞菌对哌拉西林、头孢他啶、哌拉西林/他唑巴坦、头孢吡肟的耐药率呈下降趋势,对庆大霉素、妥布霉素、阿米卡星、环丙沙星、左氧氟沙星、亚胺培南的耐药率呈上升趋势。结论 2016-2018年铜绿假单胞菌对多种抗生素耐药呈上升趋势,临床应加强铜绿假单胞菌感染监控及耐药性监测,密切关注耐药性变迁,合理选用抗生素治疗。     

2016-2018年苏州市吴江区第一人民医院病原菌的分布及耐药性分析

目的 了解2016-2018年苏州市吴江区第一人民医院常见临床分离菌株的构成及细菌耐药性情况,为临床抗感染治疗用药提供参考,促进合理用药。方法 采用自动化仪器法或纸片扩散法进行抗菌药物的敏感性试验,按照2017年临床和实验室标准化协会（CLSI）标准判读药敏结果,回顾性分析2016-2018年苏州市吴江区第一人民医院的病原菌分布及耐药性。结果 共分离病原菌35 331株,革兰阴性菌22 860株,占64.70%,主要为大肠埃希菌（6 790株,29.70%）、铜绿假单胞菌（5 244株,22.94%）、肺炎克雷伯菌（4 250株,18.59%）、鲍曼不动杆菌（1 926株,8.43%）和嗜麦芽窄食单胞菌（1 753株,7.67%）;革兰阳性菌9 676株,占27.39%,主要为金黄色葡萄球菌（5 138株,53.10%）、链球菌属（1 590株,16.43%）、肠球菌属（1 436株,14.84%）和凝固酶阴性葡球菌（928株,9.59%）;真菌2 795株,占7.91%。革兰阴性菌中产ESBLs的大肠埃希菌、产ESBLs的肺炎克雷伯菌检出率分别为48.56%、24.66%;大肠埃希菌产ESBLs菌株对氨苄西林、头孢唑啉的耐药率达100.0%,对其他抗菌药物的耐药率呈逐年上升趋势;肺炎克雷伯菌产ESBL株对阿米卡星、妥布霉素、哌拉西林/他唑巴坦、亚胺培南较敏感;肠杆菌属细菌对绝大多数抗菌药物的耐药率均较低<30%（除头孢菌素类外）;铜绿假单胞菌对大多数抗菌药物的耐药率无太大差别,3年来并无太大起伏变化,且均较低（<15%）;鲍曼不动杆菌对氨苄西林/舒巴坦、头孢他啶的耐药率呈逐年上升趋势。革兰阳性菌中检出耐甲氧西林金黄色葡萄球菌（MRSA）和耐甲氧西林凝固酶阴性葡萄球菌（MRCNS）分别为35%、73.92%。MRSA和MRCNS对青霉素类、氟喹诺酮类、大环内酯类、四环素,复方新诺明等抗菌药物的耐药率均显著高于MSSA和MSCNS株,同时对青霉素G的耐药率均已达100.0%;3年间未检测出对万古霉素、利奈唑胺和呋喃妥因耐药的葡萄球菌属细菌;屎肠球菌对青霉素类、氟喹诺酮类、红霉素、万古霉素的耐药率均显著高于粪肠球菌;3年间未检测出对利奈唑胺耐药的肠球菌属细菌,但检出有少数对万古霉素耐药的肠球菌。结论 2016-2018年苏州市吴江区第一人民医院大肠埃希菌和鲍曼不动杆菌的耐药率呈逐年上升趋势,其他细菌的耐药情况较平稳,但仍应加强院感的防控及细菌监测管理。定期监测细菌耐药性有助于了解细菌耐药性的情况,及时掌握临床病原菌耐药变化的趋势,为医院感染防控提供依据,促进临床合理应用抗菌药物和科学管理。