药敏试验的方法学进展

药敏试验的方法学进展王辉陈民钧临床微生物室的一项重要任务是对所分离的病原菌进行抗生素敏感试验（ＡＳＴ，简称药敏试验）。在细菌耐药性持续增长的今天，及时准确地向临床医生回报致病菌对抗生素的耐药性显得尤为重要。药敏试验的目的是对抗生素临床治疗的结果进行预...     

正确应用药敏标准 提供准确药敏结果

本文从做药敏试验的原则和考虑因素、无需做药敏试验的情况、选择最适药敏方法、复核罕见耐药表型结果、连续监测治疗中重复分离株的耐药性发展、检测耐药机制对药敏报告及治疗的影响等方面解读美国临床和实验室标准协会最新药敏标准文件,并综合了欧洲抗菌药物敏感性试验委员会的相关药敏规则,帮助广大临床微生物室正确应用药敏标准,向临床提供准确及时的药敏结果.     

细菌药敏试验的临床价值及局限性

细菌耐药性的迅速发展、多重耐药细菌引起的难治性感染已构成高死亡率的重要因素。原因是细菌的天然耐药谱是相对稳定的而获得性耐药谱是多变的,按传统的经验治疗常常失败。文献报道,8h内采用合理的治疗手段可降低30天的死亡率。用体外药敏试验的结果推测药物在体内的疗效,各临床实验室开展耐药监测,用回顾性的细菌耐药资料总结出常见感染细菌的耐药规律作为初始治疗的参考,以此满足临床治疗的需要。但临床实践的事实证明体外的药敏报告有时并不能达到理想的目的,临床医生和细菌室都为之困扰,因此正确理解药敏试验的临床价值、存在的局限性及合理评价药敏试验的价值十分必要。1药敏试验的临床价值在获得感染部位真正的致病菌和操作规范的前提下,体外药物敏感试验可对抗菌药物的临床疗效进行预测,查出耐药,减少治疗错误,为个体化的治疗提供参考依据;局域性的药敏试验结果的收集统计是临床医生经验治疗循证医学的证据;临床细菌室的病原检测和药敏试验可预测爆发流行的发生,为医院感染控制提供线索。自1976年WHO号召全球各临床细菌室把每天的药敏试验结果输入WHONET的软件经统计分析获得全球和各地区细菌耐药趋势、发现新的耐药机制,为临床医生合理选择抗生素提供依据。在...     

参加临床细菌学室间质量评价5年回顾和体会

本文总结了5年来参加重庆市临床细菌学室间质量评价的体会,本室45株菌种鉴定正确率93.33%,其中18株菌种加做66种抗生素药敏试验,正确率78.79%.室间质控的开展和评价能有效地提高各微生物室的检测水准.     

药敏指导的细菌感染治疗失败的分析

1药敏试验的临床价值 在获得感染部位真正的致病菌和操作规范的前提下，体外药物敏感试验可对抗菌药物的临床疗效进行预测，查出耐药，减少治疗错误，为个体化的治疗提供参考依据；局域性的药敏试验结果的收集统计是临床医生经验治疗循证医学的证据；临床细菌室的病原检测和药敏试验可预测爆发流行的发生，为医院感染控制提供线索。     

某院鲍曼不动杆菌感染分布与耐药性分析

目的 探讨该院鲍曼不动杆菌院内感染分布与耐药性情况,为临床合理用药提供依据。方法 对2013~2014年分离出来的1 336株鲍曼不动杆菌结果,使用WHONET5.6软件进行数据统计分析。结果 该院鲍曼不动杆菌感染主要以痰液标本和重症监护室(ICU)为首位;18种药敏试验结果中,15种耐药率大于70.0%(占总药敏的83.3%),仅替加环素敏感性较好(敏感性为78.7%)。结论 在临床治疗中,不能过于依赖经验性用药,应加强与微生物室的密切合作,加强细菌耐药性监测,在药敏试验结果指导下,合理使用抗菌药物,以延缓或减少鲍曼不动杆菌耐药性的产生。     

微生物实验室如何帮助医师选择合理的药物?

答:微生物实验室的技术人员应加强学习,努力提高对临床标本的检验水平和药敏试验技术,向临床报告正确的鉴定报告。我国采用的是CLSI标准,因此必须按照CLSI推荐的方法进行抗菌药物敏感性试验,包括根据不同病原菌的抗菌作用特点合理选择测试的抗菌药和有选择性的报告药敏结果(例如通常不常规报告金葡萄对利福平的药敏结果,以免不合理的单药治疗)。②努力开展细菌耐药性监测,及时向临床医师报告全院常见病原菌的耐药情况和不同病区细菌耐药现状:为医师初始用药提供重要的实验室依据。③密切注意发现新的细菌耐药机制和预测耐药细菌的暴发流行:当某病区发生医院感染暴发流行时,临床微生物室应该是最早发现的场所。如有3个或3个以上患者分离出同样的菌种,并具有相同的药敏试验耐药表型时应立即向感染控制办公室报告。有条件的实验室还应开展分子流行病学检查,通过分子生物学方法确定耐药菌之间有无同源性,以便采取有效的控制措施,减少医院感染和医疗费用。微生物实验室如何帮助医师选择合理的药物?     

脓液中的细菌培养及药敏试验分析

脓液中的细菌培养及药敏试验分析肖创清，赵绪忠（长沙１６３医院，４１０００３）为了了解造成化脓性感染的致病菌及其对药敏试验的情况，给临床治疗提供有力的参考依据，我室自１９８２年～１９９２年对１０５３份脓液标本进行了培养分离和药敏试验，并对主要致病菌的药...     

美国CLSI M52和CNAS指南关于商品化微生物鉴定系统及药敏试验系统验证方法的比较

美国临床和实验室标准化协会(CLSI)在2015年发布了文件M52-商品化微生物鉴定及药敏试验系统的验证研究,旨在为执行验证研究的实验室提供指导性建议。在实验室将商品化微生物鉴定系统和药敏试验系统应用到常规检测之前,应对未加修改而使用的已确认的检验程序进行独立验证。该文将CLSI文件M52和中国合格评定国家认可委员会(CNAS)指南中关于商品化微生物鉴定系统及药敏试验系统的验证方法进行比较,结合国内临床微生物实验室的部分情况,分析对比两者之间的差异,以供国内临床微生物实验室制定符合自身情况的验证方案。     

参加卫生部临床微生物学室间质评10年结果分析

目的总结该室2004~2013年参加卫生部临床微生物学室间质评结果,分析失控原因,提高实验室对病原菌的检测能力及药敏试验的准确性。方法对卫生部临检中心发放的质控菌株按其要求进行培养鉴定及药敏试验,将该室的结果与临检中心回报结果进行比对分析。结果 10年共收到质控样品150份,细菌的存活率为99.33%(149/150);污染率为0.67%(1/150);细菌鉴定的正确率为95.33%(143/150);药敏试验的正确率为94.76%(253/267)。结论该室对室间质评的细菌鉴定及药敏试验的正确率较高。药敏试验应注意酶学试验及处于中介水平的药敏结果,并要合理应用CLSI文件中的药敏规则。     

Legionella: a new millennium bug.

With the expanding elderly and immunocompromised populations and with creation of new ecological niches for the organism, the clinical laboratory scientist can expect to encounter Legionella in the twenty-first century. Inability to detect this pathogen with routine culture and staining techniques presents an ongoing problem. Clinical laboratory scientists need to consider implementation of special culture protocols and urinary antigen procedures. Prompt recognition of Legionella leads to the initiation of effective antimicrobial therapy. This is one area where clinical microbiology can directly affect patient outcome.     

新的微生物诊断技术对呼吸道感染诊治的影响:现状与展望

呼吸道感染是危害人类健康的重大疾病,病原学诊断的滞后使临床医生不得不求助于广谱抗感染药物的经验性治疗,细菌耐药问题越来越严重.明确呼吸道感染的病原学诊断、谨慎选择窄谱抗菌药物才是科学的应对之道.微生物学家和临床医生密切配合,善用痰涂片等传统微生物学方法;临床应用新的床旁病原学诊断技术(point-of-care test,POCT);采用高通量、标准化和自动化的分子诊断新技术,将使呼吸道感染的目标性治疗逐渐成为可能.     

PNA FISH: present and future impact on patient management

Inappropriate and inaccurate antimicrobial therapy can lead to adverse patient outcomes and also the development of antimicrobial resistance. Peptide nucleic acid (PNA) fluorescence in situ hybridization (FISH) gives rapid reporting with highly sensitive and specific results to clinicians within 3 h after blood cultures turn positive, thereby offering targeted therapeutics where necessary. It is simple to establish compared with real-time PCR and has resulted in significant cost savings for hospitals. PNA FISH is a promising future technology for the microbiology laboratory that will impact on patient management and clinical guidelines. This article will review the clinical data supporting these new technologies.     

微生物室与临床密切配合提高肺部感染的病原学诊断水平

病原学诊断不明是造成抗菌药物不合理使用的一个重要原因.微生物室应当与临床密切配合,评估呼吸道标本的质量.微生物枪验人员应当加强直接涂片和各种染色等基本功的训练,并开展快速检测手段,提高肺部感染的病原菌诊断水平.     

Characteristics of nurse practitioner curricula in the United States related to antimicrobial prescribing and resistance

PURPOSE: The purpose of this study was to examine current nurse practitioner (NP) curricula in the United States with regard to antibiotics and antimicrobial resistance and assess the need for a web-based module for instruction on antimicrobial resistance and appropriate prescribing of antibiotics. DATA SOURCES: A 22-item, anonymous, self-administered, web-based survey was sent to 312 NP programs; 149 (48%) responded. Survey items included questions related to NP specialties offered, program accreditation, format of pharmacology course(s), lecture hours related to antimicrobial therapy, and whether the participant would use a Web-based module to teach NP students about antimicrobial resistance, if one were available. CONCLUSIONS: Most NP programs (99.3%) required a pharmacology course, and 95% had lectures dedicated to antimicrobial therapy. Half of the programs (53.5%) devoted >or=4 lecture hours to antimicrobial therapy in the pharmacology course, and most (84.8%) reported covering antimicrobial therapy in nonpharmacology courses as well. Approximately half of the programs (45.3%) reported <4 h of lecture on antimicrobial therapy in nonpharmacology courses. Many programs (51.9%) did not offer a microbiology course; 39.2% required microbiology as a prerequisite. Most respondents (86.7%) were familiar with the Centers for Disease Control and Prevention antimicrobial resistance program, and 92.6% reported that they would use an electronic module regarding resistance. IMPLICATIONS FOR PRACTICE: NP curricula generally include <10 h of content on antimicrobial therapy. An electronic module regarding antimicrobial resistance is likely to be a useful and relevant adjunct to current curricula.     

Current concepts in laboratory testing to guide antimicrobial therapy

Antimicrobial susceptibility testing (AST) is indicated for pathogens contributing to an infectious process that warrants antimicrobial therapy if susceptibility to antimicrobials cannot be predicted reliably based on knowledge of their identity. Such tests are most frequently used when the etiologic agents are members of species capable of demonstrating resistance to commonly prescribed antibiotics. Some organisms have predictable susceptibility to antimicrobial agents (ie, Streptococcus pyogenes to penicillin), and empirical therapy for these organisms is typically used. Therefore, AST for such pathogens is seldom required or performed. In addition, AST is valuable in evaluating the activity of new and experimental compounds and investigating the epidemiology of antimicrobial resistant pathogens. Several laboratory methods are available to characterize the in vitro susceptibility of bacteria to antimicrobial agents. When the nature of the infection is unclear and the culture yields mixed growth or usual microbiota (wherein the isolates usually bear little relationship to the actual infectious process), AST is usually unnecessary and results may, in fact, be dangerously misleading. Phenotypic methods for detection of specific antimicrobial resistance mechanisms are increasingly being used to complement AST (ie, inducible clindamycin resistance among several gram-positive bacteria) and to provide clinicians with preliminary direction for antibiotic selection pending results generated from standardized AST (ie, β-lactamase tests). In addition, molecular methods are being developed and incorporated by microbiology laboratories into resistance detection algorithms for rapid, sensitive assessment of carriage states of epidemiologically and clinically important pathogens, often directly from clinical specimens (ie, presence of vancomycin-resistant enterococci in fecal specimens).     

Procalcitonin and the role of biomarkers in the diagnosis and management of sepsis

Sepsis and severe sepsis cause significant morbidity and mortality among populations worldwide; the rapid diagnosis poses a considerable challenge to physicians in acute care settings. An ideal biomarker should allow, with high diagnostic accuracy, for an early and rapid recognition of sepsis. Procalcitonin (PCT) is a recently rediscovered biomarker that fulfills many of these requirements, especially in comparison to "older" and commonly used biomarkers, and that has demonstrated superior diagnostic accuracy for a variety of infections, including sepsis. While blood cultures are still considered the "gold standard" for the diagnosis of bacteremia and sepsis, and are perhaps one of the most important functions of the clinical microbiology laboratory, PCT provides important information in early stages of sepsis as well as during antimicrobial treatment. In fact, PCT can be useful for antimicrobial stewardship and its utilization may safely lead to significant reduction of unnecessary antimicrobial therapy. However, PCT is also less than a universal and perfect biomarker, as it can also be increased in noninfectious disease conditions. Laboratories and clinicians must appreciate the complexity of diagnostic algorithms for sepsis and understand the particular information that biomarkers, such as PCT, can offer. In that context, it is necessary to not only recognize the importance of critical clinical awareness and thorough physical patient examination, but also to understand traditional microbiological methods and the need for highly sensitive biomarker assays in order to facilitate an early diagnosis and goal-directed therapy in patients suspected of sepsis. This review is intended to provide additional information for clinicians and microbiologists to better understand the physiology and diagnostic utility of procalcitonin for sepsis and other infectious disease conditions.     

葡萄球菌属对抗菌药物的耐药性分析

目的了解葡萄球菌属临床分离株的耐药性及对大环内酯类、林可霉素类及链阳霉素类（MLS）的耐药表型。方法用Kirby-Bauer法测定葡萄球菌属对14种抗菌药的敏感性，进行D试验测定MLS耐药表型。结果在230株葡萄球菌属中，耐甲氧西林金葡菌（MRSA）和耐甲氧西林凝固酶阴性葡萄球菌（MRSCN）分别为9．9％和79．8％。对青霉素都呈现高度耐药。未发现万古霉素及替考拉宁耐药菌株，126株葡萄球菌属对红霉素耐药，54．8％（23／42）株金葡菌为结构型耐药；在凝固酶阴性葡萄球菌中（CNS），44．0％（37／84）为结构型耐药，41．7％（35／84）为外排型耐药。对红霉素耐药但对克林霉素敏感的葡萄球菌中，17株为诱导型克林霉素耐药。结论应加强对葡萄球菌的耐药性监测，临床微生物实验室应进行D试验。指导临床合理使用抗生素。     

Antimicrobial resistance testing in clinical practice

Previously unrecognized or underrecognized antimicrobial resistant bacteria, including NDM-1-producing Enterobacteriaceae and multidrug-resistant Acinetobacter baumannii, were recently identified in health care facilities in Japan. Vigilance in the clinical microbiology laboratory for these organisms is the key to early recognition of their emergence. Many of these organisms can be confirmed or at least suspected through routine susceptibility testing, which can then be referred to reference laboratories for further phenotypic or genetic testing. Antimicrobial resistance testing plays a crucial role in patient management, infection control and monitoring of local as well as national and international epidemiology.     

In vitro susceptibility testing versus in vivo effectiveness

The clinical relevance of susceptibility testing has always been questioned because of the difficulty of correlating in vitro susceptibility testing with in vivo clinical effectiveness. Clearly there have always been host/pathogen factors that influence the clinical outcome that cannot be predicted by the results of susceptibility testing. However, improved understanding of pharmacodynamic and pharmacokinetic parameters has greatly improved the use of antimicrobial agents. Most importantly, the integration of these pharmacodynamic and pharmacokinetic indices has greatly improved the correlation between in vitro susceptibility testing and in vivo clinical effectiveness and allows more realistic breakpoints. Finally, the clinical microbiology laboratory has advanced with improved methods as well as the adaptation of breakpoints that are more realistic.