深部感染真菌对常用抗真菌药物的耐药性

目的:调查北京医院2003年4月～10月期间真菌感染的菌种分布及耐药性,指导临床合理用药.方法:采用显色培养基对真菌进行鉴定,用药敏纸片法测定真菌对氟康唑、伊曲康唑和两性霉素B的敏感性.结果:共分离到285株真菌,主要来源于呼吸道、泌尿道和消化道,其中检出最多的是白色假丝酵母133株(46.7%)、光滑假丝酵母66株(23.2%)和热带假丝酵母54株(18.9%).三种抗真菌药物对285株深部感染真菌总的耐药率分别为氟康唑10.9%、伊曲康唑7.7%和两性霉素B0%.对氟康唑耐药的有光滑假丝酵母26株、克柔假丝酵母1株、季也蒙假丝酵母2株和白色假丝酵母2株;对伊曲康唑耐药性较高有克柔假丝酵母1株、季也蒙假丝酵母2株、热带假丝酵母5株、光滑假丝酵母12株和白色假丝酵母2株.结论:定期开展真菌的耐药监测,有助于合理应用抗真菌药物.     

新生儿重症监护病房真菌感染情况分析

摘要目的了解新生儿重症监护病房近3年真菌感染种类及耐药现状,以指导临床合理选用抗真菌药物。方法收集湖北省人民医院新生儿病房2009年1月～2011年12月收治的139例体液培养真菌阳性的患儿资料,对真菌菌种分布及其耐药性、真菌感染部位进行统计分析。结果共检出11种139株病原菌,其中白假丝酵母菌79株（56.83%）,光滑假丝酵母菌21株（15.11%）,热带假丝酵母15株（10.79%）,清酒假丝酵母11株（7.91%）;新生儿真菌感染部位主要是消化道,其次为呼吸道、泌尿道、血液、皮肤。药敏试验结果显示白假丝酵母菌对两性霉素B耐药率0%,对5 氟胞嘧啶耐药率2.53%,对唑类药物耐药率2.53%～5.06%。结论白假丝酵母菌是新生儿真菌感染主要病原菌,非白念珠真菌如光滑假丝酵母、热带假丝酵母、清酒假丝酵母感染增多,应引起重视。各类真菌对氟康唑的耐药性低,可作为新生儿抗真菌治疗经验用药,应根据药敏试验结果选用抗真菌药物。     

住院患者真菌感染的菌群分布及耐药性分析

目的了解住院患者临床分离的真菌分布情况以及对常用抗真菌药的敏感性,为临床合理使用抗真菌药提供参考依据。方法收集我院2013年1月至2015年12月真菌感染的住院患者的临床资料,对其分布情况和药敏结果进行分析。结果住院患者中共分离出431株真菌,其中白色假丝酵母菌所占比例最高(33.6%),其次是菌膜假丝酵母菌(15.5%)、近平滑假丝酵母菌(13.2%)、光滑念珠菌(12.3%)。白色假丝酵母菌、近平滑假丝酵母菌、菌膜假丝酵母菌对伏立康唑及氟康唑的耐药率均为0。白色假丝酵母菌对伊曲康唑的耐药率和菌膜假丝酵母菌对氟胞嘧啶的耐药率均呈逐年上升趋势。结论不同真菌对临床常用抗真菌药物有不同程度的耐药性,临床医师应结合药敏结果合理选用抗真菌药,减少医院真菌感染的发生。     

临床酵母样真菌感染特点及药敏分析

目的通过了解沈阳医学院沈洲医院检验科微生物室收检的各类临床标本中分离到的各类酵母样真菌的菌群分布特点及耐药情况,从而指导临床合理使用抗真菌药物、有效预防真菌感染和耐药性的发生。方法所有菌株均分离自沈洲医院临床送检的痰液、尿液、粪便、咽拭子、分泌物等。实验采用贝瑞特公司的沙保弱琼脂培养基分离培养真菌,用法国生物梅里埃公司生产的ATB Expression微生物半自动鉴定/药敏分析仪进行真菌鉴定和药敏分析。结果临床酵母样真菌检出率最高的为白假丝酵母菌（65.6%）,其次为热带假丝酵母菌（13.9%）、光滑假丝酵母菌（11.1%）、近平滑假丝酵母菌（6.1%）、其他酵母样真菌（3.3%）;180株酵母样真菌对5种抗真菌药物（两性霉素B、5-氟胞嘧啶、伏立康唑、伊曲康唑、氟康唑）的平均耐药率依次为2.1%、5.5%、22.3%、25.6%、39.6%。结论 180株酵母样真菌中,白假丝酵母菌检出率最高,其次为热带酵母菌;标本来源中痰液标本所占比例最高,其次为便和尿液标本;耐药监测中酵母样真菌对两性霉素B耐药性最低,对氟康唑耐药性最高。     

某院2017年-2019年96例假丝酵母感染性阴道炎患者阴道分泌液中真菌的分布对临床治疗的影响

目的:分析医院妇科假丝酵母感染性阴道炎患者阴道分泌物中真菌的分布对临床治疗的影响。方法:抽取2017年—2019年间诊疗的假丝酵母感染性阴道炎患者96例临床资料,分析其阴道后穹窿分泌物中真菌的培养结果,以及不同年龄段患者真菌的分布情况与药敏试验结果。结果:96例假丝酵母感染性阴道炎患者年龄段的分布以22~50岁为主,而<22岁和>50岁年龄段的患者人数较少;96例患者中分离出假丝酵母74株,其中以白假丝酵母为最多占77.03%,其次为光滑假丝酵母和克柔假丝酵母分别占10.81%和6.76%,近平滑假丝酵母仅检出1株(占1.35%);白假丝酵母、克柔假丝酵母对常用的抗真菌药物均具有较低的耐药率(低于10.00%),而对两性霉素B的耐药率仅为0.00%;而光滑假丝酵母对益康唑、氟康唑、咪康唑的耐药率分别为62.50%、75.00%和75.00%,而对其他抗真菌药物的耐药率较低。结论:医院妇科诊疗患者的假丝酵母感染性阴道炎主要以白假丝酵母为最多,临床应根据药敏试验结果合理选用敏感率高的抗真菌药物治疗,以确保其临床疗效。     

临床标本中常见真菌的检出与药物敏感性分析

目的探讨临床标本中常见真菌的类型与药物敏感情况,给临床诊治提供依据。方法对临床送检的多种标本培养真菌,检测、鉴定和药敏分析。结果多种标本均检出真菌,培养的真菌依次为白假丝酵母菌、热带假丝酵母菌、近平滑假丝酵母菌、克柔假丝酵母菌,其中白假丝酵母菌对多种抗真菌药有较高的敏感性。结论临床应重视真菌的分离、培养、鉴定和药敏试验,有利于提高抗真菌药物的选择,对临床合理使用抗真菌药物具有指导意义。     

白假丝酵母菌对抗真菌药物敏感性分析

目的了解院内白假丝酵母菌感染菌株对常用抗真菌药物敏感情况并探讨伊曲康唑对白假丝酵母菌生物膜形成的影响。方法采用Rosco纸牌扩散法检测附属海慈医院临床分离的白假丝酵母菌对5种抗真菌药物的药物敏感性,采用96孔培养板进行白假丝酵母菌生物膜的培养,利用CCK-8试剂盒来检测生物膜不同时期的活性及对伊曲康唑的敏感性。结果临床标本107例,检出白假丝酵母菌47例,感染率为43．9％。体外药敏试验显示临床株白色假丝酵母菌对抗真菌药两性霉素B和制霉素敏感性较高（45％、85％）,而对康唑类抗真菌药物产生了耐药性。白假丝酵母菌生物膜形成早期（8h）生长较快,24h形成成熟稳定的生物膜,游离态的白假丝酵母菌对伊曲康唑的MIC50为2μg／mL,不同浓度伊曲康唑处理组生物膜活性均有所降低。结论白假丝酵母菌对常用抗真菌药物的耐药性呈上升趋势。经抗菌性处理的生物材料对预防生物膜的形成有抑制作用。     

羊毛甾醇脱甲基酶变化导致假丝酵母耐药的分子生物学研究进展

假丝酵母是临床常见的条件致病菌,抗生素的滥用及放化疗和免疫抑制剂广泛使用,使得假丝酵母的感染机会增加,针对常见的吡咯类抗真菌药的耐药现象逐年增加,其耐药途径较多,包括细胞膜对药物的通透性下降,药物在细胞内降解,甾醇合成路径的改变,细胞膜的排出泵作用增强,甾醇合成酶的性质变化等,与假丝酵母耐药性相关的细胞色素P－450羊毛甾醇脱甲基酶的基因存在4种改变：（1）点突变;（2）基因过度表达;（3）基因扩增;（4）基因转换或有丝分裂重组,导致靶酶的生物学特性变化,及其与假丝酵母药性的相互关系,表明假丝酵母编码靶酶的基因的变化可导致靶酶一级结构改变和空间构象变化,影响药物对靶酶的亲和性,或导致靶酶量的变化。影响药物的作用,产生耐药性。     

中药单体成分抗白假丝酵母作用的研究进展

近年来,随着抗菌药物、糖皮质激素药物的不合理使用,以白假丝酵母为主的真菌感染发病率不断升高,且其对传统抗真菌药物的耐药问题日益严峻.中药单体作为抗白假丝酵母药物具有来源广泛、价格低廉、副反应轻微等特点.文中综述从不同机制对各种常见中药单体成分抗白假丝酵母的作用文献,并对其研究进展做了分析,为探寻白假丝酵母相关感染患者的临床治疗新思路提供参考.     

中药单体成分抗白假丝酵母作用的研究进展

近年来,随着抗菌药物、糖皮质激素药物的不合理使用,以白假丝酵母为主的真菌感染发病率不断升高,且其对传统抗真菌药物的耐药问题日益严峻.中药单体作为抗白假丝酵母药物具有来源广泛、价格低廉、副反应轻微等特点.文中综述从不同机制对各种常见中药单体成分抗白假丝酵母的作用文献,并对其研究进展做了分析,为探寻白假丝酵母相关感染患者的临床治疗新思路提供参考.     

Cerulenin Analogues as Inhibitors of Efflux Pumps in Drug‐resistant Candida albicans

Overexpression of the ABC transporters Cdr1 and Cdr2 or the major facilitator Mdr1 causes multidrug resistance in the human fungal pathogen Candida albicans. The fatty acid synthesis inhibitor cerulenin and the structurally unrelated Golgi transport inhibitor brefeldin A are substrates for both types of efflux pumps in Candida albicans. In an effort to overcome efflux pump‐mediated drug resistance in Candida albicans, cerulenin analogues were generated using a variety of synthesis pathways. The so obtained cerulenin derivatives were tested on multidrug‐resistant Candida albicans isolates which constitutively overexpress either Mdr1 or Cdr1 and Cdr2. Some of these compounds were found to decrease Mdr1‐mediated resistance to brefeldin A up to eightfold compared to the control.     

Membrane transporters and antifungal drug resistance

Over the last 30 years or so, the incidence of invasive fungal infections in man has risen dramatically. Patients that become severely immunocompromised because of underlying diseases such as leukemia or recently, acquired immunodeficiency syndrome or patients who undergo cancer chemotherapy or organ transplantation, are particularly susceptible to opportunistic fungal infections. Although Candida species continue to be the major pathogenic fungi in these patients, cryptococcosis, aspergillosis, and coccidioidomycosis, among others, have become increasingly important mycoses. Antifungal drugs currently being used in clinic include polyene antibiotics, azole derivatives and 5-fluorocytosine. With the exception of the latter, all other drugs possess mechanisms of action aimed at disrupting the integrity of the fungal cell membrane by either interfering with the biosynthesis of membrane sterols or by inhibiting sterol functions. However, one significant obstacle preventing successful antifungal therapy is the dramatic increase in drug resistance, especially against azole antimycotics. Among the major mechanisms by which fungi invoke drug resistance is the overexpession of extrusion pumps able to facilitate the efflux of cytotoxic drugs from the cell thus leading to decreased drug accumulation and diminished concentrations. Since the initial observations that azole resistance by fungi may be caused by overexpression of multidrug efflux transporter genes, significant advances have been achieved primarily with Saccharomyces cerevisiae and Candida albicans. The purpose of this review is to discuss various aspects of multidrug resistance in fungi such as antifungal drug mechanisms of action and fungal molecular genetics in the context of targeted drug discovery. The role that membrane transporter proteins play in drug resistance in various species of Candida, Aspergillus and Cryptococcus will be address in more detail, as will be their importance as selective drug targets in the design of novel antifungal agents.     

2018-2022年深圳市妇幼保健院分离真菌的分布及耐药情况分析

目的 调查分析南方医科大学附属深圳妇幼保健院分离真菌的分布特点和药物敏感性情况,为妇幼真菌感染疾病的临床诊治、耐药性监测和流行病学研究提供参考。方法 回顾分析南方医科大学附属深圳妇幼保健院2018年1月-2022年12月标本采集、真菌鉴定和抗真菌药敏试验的结果数据。结果 共分离真菌3 350株,前2位分别为白色念珠菌1 542株、光滑念珠菌223株。阳性标本以阴道分泌物/宫颈分泌物为主。妇科和产科分离到的真菌最多。白色念珠菌对伊曲康唑、伏立康唑的5年耐药率分别为9.58%、4.12%,对两性霉素B和5-氟胞嘧啶的5年敏感率分别为99.79%、98.01%,对氟康唑的历年敏感率有逐渐升高的态势。光滑念珠菌、近平滑念珠菌和热带念珠菌对两性霉素B及5-氟胞嘧啶的敏感率均为100.00%。克柔念珠菌对两性霉素B和伏立康唑100.00%敏感。结论 南方医科大学附属深圳妇幼保健院分离真菌以念珠菌属为主,其中白色念珠菌最多。阴道分泌物/宫颈分泌物是主要真菌阳性分离标本。白色念珠菌对两性霉素B的耐药率最低、敏感率最高,对伊曲康唑的耐药率最高、敏感率最低。光滑念珠菌、近平滑念珠菌、热带念珠菌和克柔念珠菌对两性霉素B和5-氟胞嘧啶均无耐药性。光滑念珠菌对伊曲康唑耐药率最高、敏感率最低。     

Efflux as a mechanism of antimicrobial drug resistance in clinical relevant microorganisms: the role of efflux inhibitors

Introduction: Microbial resistance against antibiotics is a serious threat to the effective treatment of infectious diseases. Several mechanisms exist through which microorganisms can develop resistance against antimicrobial drugs, of which the overexpression of genes to produce efflux pumps is a major concern. Several efflux transporters have been identified in microorganisms, which infer resistance against specific antibiotics and even multidrug resistance.

Areas covered: This paper focuses on microbial resistance against antibiotics by means of the mechanism of efflux and gives a critical overview of studies conducted to overcome this problem by combining efflux pump inhibitors with antibiotics. Information was obtained from a literature search done with MEDLINE, Pubmed, Scopus, ScienceDirect, OneSearch and EBSCO host.

Expert opinion: Efflux as a mechanism of multidrug resistance has presented a platform for improved efficacy against resistant microorganisms by co-administration of efflux pump inhibitors with antimicrobial agents. Although proof of concept has been shown for this approach with in vitro experiments, further research is needed to develop more potent inhibitors with low toxicity which is clinically effective.     

Overcoming multidrug resistance with nanomedicines

Introduction: Cancer remains the leading cause of death worldwide. Numerous therapeutic strategies that include smart biological treatments toward specific cellular pathways are being developed. Yet, inherent and acquired multidrug resistance (MDR) to chemotherapeutic drugs remains the major obstacle in effective cancer treatments.

Areas covered: Herein, we focused on an implementation of nanoscale drug delivery strategies (nanomedicines) to treat tumors that resist MDR. Specifically, we briefly discuss the MDR phenomenon and provide structural and functional characterization of key proteins that account for MDR. We next describe the strategies to target tumors using nanoparticles and provide a mechanistic overview of how changes in the influx:efflux ratio result in overcoming MDR.

Expert opinion: Various strategies have been applied in preclinical and clinical settings to overcome cancer MDR. Among them are the use of chemosensitizers that aim to sensitize the cancer cells to chemotherapeutic treatment and the use of nanomedicines as delivery vehicles that can increase the influx of drugs into cancer cells. These strategies can enhance the therapeutic response in resistant tumors by bypassing efflux pumps or by increasing the nominal amounts of therapeutic payloads into the cancer cells at a given time point.     

The development of efflux pump inhibitors to treat Gram-negative infections

ABSTRACT

Introduction: One of the possibilities for reducing the emergence and spread of antibiotic resistance is the use of anti-resistance compounds capable of resensitizing resistant microorganisms to current antimicrobials. For this purpose, multidrug efflux pumps, whose inhibition may increase bacterial susceptibility to several antibiotics, including macrolides to which Gram-negatives are considered intrinsically resistant, have emerged as suitable targets.

Areas covered: In the current review, the authors discuss different mechanisms that can be exploited for inhibiting multidrug efflux pumps and describe the properties and the potential therapeutic value of already studied efflux pumps inhibitors. Although efforts have already been made to develop these inhibitors, there are currently no good candidates for treating infectious diseases. Consequently, the authors also discuss potential approaches for their development.

Expert opinion: Classical anti-resistance drugs such as beta-lactamases inhibitors, while useful, are only purposeful for treating infections caused by beta-lactamase producers. However, inhibitors of multidrug efflux pumps, which are present on all organisms, can sensitize both susceptible and resistant bacteria to antibiotics belonging to several different structural families. Since some efflux pumps are involved in bacterial infections, their inhibition may also reduce the infectivity of Gram-negative bacterial pathogens.     

2014—2017年解放军总医院海南分院真菌分布及耐药性分析

目的 了解2014—2017年解放军总医院海南分院真菌的分布和耐药特点,为促进抗真菌药的合理应用、有效减缓真菌耐药提供参考。方法 提取解放军总医院海南分院2014年1月—2017年12月临床真菌分离和药敏相关数据,分析真菌的分布特征及其对常用抗真菌药的耐药率和变化趋势。结果 共纳入1 048份阳性真菌样本,呼吸道标本占41.89%,60岁以上患者（61.45%）和重症医学科（25.48%）分布比例最高;共分离出1 329株真菌,白色念珠菌、念珠菌属、热带念珠菌分别占24.53%、15.80%、13.69%。各种念珠菌对两性霉素B和5-氟胞嘧啶的敏感率基本保持在90%以上;热带念珠菌对伊曲康唑耐药率最高,达10%～20%,对氟康唑和伏立康唑的耐药率亦高于两性霉素B和5-氟胞嘧啶;白色念珠菌对伊曲康唑和伏立康唑的耐药率呈逐年快速上升趋势。结论 白色念珠菌和热带念珠菌感染应慎用唑类抗真菌药;两性霉素B和5-氟胞嘧啶是念珠菌感染的有效选择。     

Exploration of 5‐(5‐nitrothiophen‐2‐yl)‐4,5‐dihydro‐1H‐pyrazoles as selective,multitargeted antimycobacterial agents

We report the biological evaluation of 5‐(5‐nitrothiophen‐2‐yl)‐4,5‐dihydro‐1H‐pyrazole derivatives against bacteria, eukaryotic cell lines and the assessment of their mechanisms of action to determine their prospects of being developed into potent antituberculosis agents. The compounds were evaluated for their antibacterial property against Mycobacterium tuberculosis H37Rv, multidrug‐resistant M. tuberculosis, Mycobacterium bovis BCG, Mycobacterium aurum, Escherichia coli, and Staphylococcus aureus using high‐throughput spot‐culture growth inhibition assay. They were found to be selective toward slow‐growing mycobacteria and Gram‐positive bacteria. In M. bovis BCG, they exhibited a bactericidal mode of action. Cytotoxicity was assessed in human THP‐1 and murine RAW 264.7 cell lines, and the compounds showed a lower cytotoxicity potential when compared with their antibacterial activity. They were found to be excellent whole‐cell efflux pump inhibitors of the mycobacterial surrogate M. aurum, performing better than known efflux pump inhibitor verapamil. The 5‐nitrothiophene moiety was identified for the first time as a prospective inhibitor scaffold of mycobacterial arylamine N‐acetyltransferase enzyme, which is the key enzyme in metabolizing isoniazid, a first‐line antituberculosis drug. The two aforementioned findings make the compounds potential hits in the development of adjunctive tuberculosis therapy.     

Paclitaxel-loaded PLGA nanoparticles surface modified with transferrin and Pluronic®P85, an in vitro cell line and in vivo biodistribution studies on rat model

The development of multidrug resistance (due to drug efflux by P-glycoproteins) is a major drawback with the use of paclitaxel (PTX) in the treatment of cancer. The rationale behind this study is to prepare PTX nanoparticles (NPs) for the reversal of multidrug resistance based on the fact that PTX loaded into NPs is not recognized by P-glycoproteins and hence is not effluxed out of the cell. Also, the intracellular penetration of the NPs could be enhanced by anchoring transferrin (Tf) on the PTX-PLGA-NPs. PTX-loaded PLGA NPs (PTX-PLGA-NPs), Pluronic^®P85-coated PLGA NPs (P85-PTX-PLGA-NPs), and Tf-anchored PLGA NPs (Tf-PTX-PLGA-NPs) were prepared and evaluted for cytotoxicity and intracellular uptake using C6 rat glioma cell line. A significant increase in cytotoxicity was observed in the order of Tf-PTX-PLGA-NPs > P85-PTX-PLGA-NPs > PTX-PLGA-NPs in comparison to drug solution. In vivo biodistribution on male Sprague–Dawley rats bearing C6 glioma (subcutaneous) showed higher tumor PTX concentrations in animals administered with PTX-NPs compared to drug solution.