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1、革兰阴性菌耐药折点问题,北京大学人民医院检验科 王辉 ,CLSI AST Standards January 2012,M100-S22 Tables (2012)* M02-A11 Disk Diffusion Method (2012)* M07-A9 MIC Method (2012)* M11-A7 Anaerobe MIC Testing (2007),New!,3,M100-S22 Partial Table of Contents,M100-S22. Page 9.,4,更新的 的总结,M100-S22. Page 13.,5,2012主要变化,肠杆菌科 修订厄他培南折点 增加环
2、丙沙星折点（伤寒沙门菌和胃肠外沙门菌） 绿脓杆菌 降低 哌拉西林、哌拉西林/他唑巴坦、替卡西林、替卡西林/克拉维酸折点 降低 亚胺培南、美罗培南折点；增加多利培南折点 葡萄球菌 增加金葡菌青霉素抑菌圈周边试验检测（ penicillin disk zone edge test） -内酰胺酶产生,New!,6,M100-S22. P22,2010年后折点变化过程,New!,7,CLSI Breakpoint Additions / Revisions Since 2010,CLSI Breakpoint Additions / Revisions Since 2010,肠杆菌科： 碳靑霉烯类,美
3、国碳靑霉烯类耐药肠杆菌科（CRE）的分布,黄色：KPC酶； 蓝点：IMP、VIM 黄点：NDM,CLSI使用以下数据建立 / 修订折点,“野生菌群” 或常规菌群的MIC分布 野生菌群= 未携带获得性“耐药”机制 与临床预后相关的MIC 对于老药很少有“新”数据 药物代谢-药效学 (PK-PD) 分析,CLSI M23-A3 (2008) “体外药敏实验标准和质量控制参数的发展; 批准的指南” 描述了CLSI建立和修订折点的过程。,Piperacillin-tazobactam MIC distribution example Blue = wild type isolates Red = is
4、olates with acquired “R” mechanism,www.eucast.org,10,Serum Concentration (g/ml),Time (hours),MIC,Time above MIC,dose,dose,Cmax (peak concentration),PK/PD Goal (“Target”) for -lactams = (%T MIC),12,DMID 2009年,肠杆菌科 厄他培南 CLSI 折点更新过程,*目前和FDA折点相同,New,New!,28,为何多次进行修改?,2011 breakpoints primarily based on:
5、 MIC distributions PK/PD (conservatively went with 0.25 g/ml) Very limited clinical data (no patients with MICs at 0.5 g/ml) 2012 breakpoints primarily based on: Additional surveillance data showed isolates with MICs of 0.5 g/ml did not have carbapenemases Further review of PK/PD Additional clinical
6、 data (including ESBL-producing E. coli with 0.5 g/ml MICs suggested clinical response) Also, lowest ertapenem concentration on some commercial panels is 0.5 g/ml thus allowing labs to use CLSI ertapenem breakpoints (following verification) if breakpoint is 0.5 g/ml but not if 0.25 g/ml,29,CLSI Agen
7、da Book June 2011,30,CLSI Agenda Book June 2011,31,Susc.: 0.5 g/ml / 22 mm Res.: 2 g/ml / 18 mm VM = 0.0% Ma = 0.0% Mi = 6.1%,FOR NEW BREAKPOINTS APPROVED June 2011,Modified Hodge Test (MHT) (Table 2A Supplemental Table 2 and 3),“NOTE: Not all carbapenemase-producing isolates of Enterobacteriaceae a
8、re MHT positive and MHT-positive results may be encountered in isolates with carbapenem resistance mechanisms other than carbapenemase production.”,M100-S22. Table 2A Supplemental Tables 2 and 3. Pages 53 and 57.,New!,36,4 Select CRE Examples: Carbapenem MICs & MHT & -Lactam Resistance Mechanism,1 I
9、nterpreted with current breakpoints 2 Anderson, KF et al. 2009. ICAAC. D-719. 3 Limbago, BM. CLSI Agenda book. January 2011. 4 MHT positive only with ertapenem disk 5 MHT same result with ertapenem and meropenem (and imipenem) disks 6 Carbapenemases (metallo -lactamases),39,进行耐药机制的初筛试验 (MIC升高至接近“敏感”
10、折点为 “可疑”),进行耐药机制的特异确证试验,若检测到耐药机制则更改药敏报告,发现一种新型-内酰胺酶 (如ESBL或碳青霉烯酶),旧的模式,ESBL,MHT,Courtesy of Dr. Jean Patel CDC,新的模式,进行药敏试验并且使用 新的“降低的”折点,以治疗为目的报告药敏结果 不更改“敏感”结果,仅以感染控制和流行病学研究为目的进行特殊的耐药机制检测试验,分离出肠杆菌科菌,Courtesy of Dr. Jean Patel CDC,CLSI M100-S20-U 表 1A 修订的碳青霉烯类药物折点和对应的药物剂量,S I R,S I R,（22）解释标准基于每8小时一次
11、，每次500mg的给药方案。 （23）解释标准基于每天一次，每次1g的给药方案。 （24）解释标准基于每6小时一次，每次500mg或每8小时一次，每次1g的给药方案。 （25）解释标准基于每8小时一次，每次1g的给药方案。,M100-S22. Table 2A Supplemental Tables 2 and 3. Pages 52-60.,(旧折点),(当前折点),MHT检测碳青霉烯酶,35,碳青霉烯类药物MIC 报告策略,*对常规病人的报告不必做改良霍奇试验; 可以为感染控制目的而进行该试验 但不要把 “敏感” 或“中介” 改为 “耐药”,折点 (g/ml),如果用 旧折点 和 碳青霉烯
12、酶筛选试验阳性,如果用 当前折点 和 需要流行病学的需要,进行MHT,进行MHT,为何做 MHT?,M100-S22. Comment (23) Page 47. Table 2A Supplemental Tables 2 and 3. Pages 52 and 56.,40,绿脓杆菌,57,Pseudomonas aeruginosa Breakpoint (MIC g/ml) Revisions,1 Corresponding disk diffusion breakpoints also revised,M100-S22. Table 2B-1. Page 63.,New!,58,Ps
13、eudomonas aeruginosa,M100-S22. Table 2B-1. Page 63.,Dosage comments (3 g every 6 h also for piperacillin and for ticarcillin),59,2012年CLSI 绿脓杆菌折点变化,Section III. Therapy-Related Comments,“In cases where specific dosage regimens are important for proper application of breakpoints, the dosage regimen i
14、s listed. These dosage regimen comments are not intended for use on individual patient reports.”,M100-S22. Instructions. Page 28.,New!,60,Pseudomonas aeruginosa Penicillins +/- -lactamase Inhibitors,P. aeruginosa breakpoints originally set higher than those for Enterobacteriaceae based in part on FD
15、A label noting that these drugs should be considered in combination therapy with aminoglycoside Deleted comment from Table 2B-1 - “Rx: The susceptible category for penicillins, -lactam/-lactamase inhibitors implies the need for high-dose therapy for serious infections caused by P. aeruginosa. For th
16、ese infections, monotherapy has been associated with clinical failure” P. aeruginosa MIC breakpoints are now the same as those for Enterobacteriaceae (slight differences in disk diffusion breakpoints),61,Outcomes of bacteremia (N=34 episodes) due to P. aeruginosa with reduced susceptibility to piper
17、acillin-tazobactam,Tam et al. 2008. Clin Infect Dis. 46:862.,Clinical data suggest former breakpoints too high!,62,Pseudomonas aeruginosa Breakpoint (MIC g/ml) Revisions,1 corresponding disk diffusion breakpoints also revised 2 Interpretive criteria are based on dosage regimens of 500 mg every 8 h 3
18、 Interpretive criteria are based on dosage regimens of 1 g every 8 h,M100-S22. Table 2B-1. Page 63.,New!,63,提醒!,美国同时有 CLSI和FDA 折点 CLSI and FDA建立折点的过程略有不同 商业系统 MUST 使用FDA折点 临床实验室可以使用 CLSI 或 FDA 折点 认证机构接受 如果是 FDA-批准的商业 AST 系统, 临床实验室使用更新的CLSI折点时，需要验证,8,S. typhi and Extraintestinal Salmonella spp. and F
19、luoroquinolones,41,M100-S22. Table 2A. Page 48.,S. typhi and Extraintestinal Salmonella spp. and Fluoroquinolones,New!,45,M100-S22. Table 2A. Page 48.,S. typhi and Extraintestinal Salmonella spp. and Ciprofloxacin,New!,47,Staphylococcus spp. - Penicillin,68,Induced -lactamase Test,苯唑西林 (诱导剂),Sub iso
20、late to agar (e.g., BAP, MHA) Drop -lactam disk (e.g., oxacillin, cefoxitin) Incubate overnight Test cells from periphery of zone If -lactamase positive (with or without induction), report penicillin R,Pos,Neg,71,Cloverleaf Assay for -lactamase S. aureus,5% sheep blood agar 1 unit penicillin disk S.
21、 aureus ATCC 25923 as the indicator -lactamase negative (penicillin S) strain Some difficulties reading,Isolates A-D are all -lactamase positive,A,B,C,D,-lactamase negative,75,-lactamase positive,-lactamase negative,76,Staphylococcus aureus Disk Zone Edge Test (10 U penicillin disk and standard disk
22、 diffusion method ),Fuzzy “beach” = -lactamase negative Penicillin - S,Sharp “cliff” = -lactamase positive Penicillin - R,S. aureus QC: Neg - ATCC 25923 Pos - ATCC 29213 (supplemental QC),M100-S22. Table 2C Supplemental Table 1. Page 83.,New!,77,M100-S22. Table 2C Supplemental Table 1. Page 80.,-lac
23、tamase Tests S. aureus and S. lugdunensis,80,-lactamase Tests CoNS NOT S. lugdunensis,M100-S22. Table 2C Supplemental Table 3. Page 88.,81,CLSI vs FDA Interpretive Criteria,If the regulatory authority changes breakpoints, commercial device manufacturers may have to conduct a clinical laboratory tria
24、l, submit the data to the regulatory authority, and await review and approval. For these reasons, a delay of one or more years may be required if an interpretive breakpoint change is to be implemented by a device manufacturer. In the United States, laboratories that use Food and Drug Administration
25、(FDA)approved susceptibility testing devices are allowed to use existing FDA interpretive breakpoints. Either FDA or CLSI susceptibility interpretive breakpoints are acceptable to clinical laboratory accrediting bodies. Policies in other countries may vary. Laboratories should check with the manufac
26、turers of their antimicrobial susceptibility test system for additional information on the breakpoints used in their systems software.,CLSI vs FDA,Following discussions with appropriate stakeholders, such as infectious disease practitioners and the pharmacy department, as well as the Pharmacy and Th
27、erapeutics and Infection Control committees of the medical staff, newly approved or revised breakpoints may be implemented by clinical laboratories. CLSI disk diffusion test breakpoints may be implemented as soon as they are published in M100. If a device includes antimicrobial test concentrations s
28、ufficient to allow interpretation of susceptibility and resistance to an agent using the CLSI breakpoints, a laboratory could, after appropriate validation, choose to interpret and report results using CLSI breakpoints.,CLSI AST Standards for Routine AST,MIC,折点-表格,纸片扩散法,MIC方法,All New 2012!,22,“感染性疾病
29、的病原学诊断及临床应用新进展学习班”通知,北京 6月27-7月1日 国家级继续教育学分10分 临床微生物学检验和感染疾病诊治指导意义 ISO15189与微生物检验 寄生虫病的临床和实验室诊断进展 真菌病的实验室诊断和新进展 不明原因肺炎的临床和实验室诊断进展 下呼吸道标本采集、运送和处理规范 无菌体液微生物检验的规范流程 临床不常见菌的培养和快速鉴定 药敏试验折点建立和抗菌药物的PK/PD 2012年CLSI药敏试验更新 细菌耐药监测和药敏谱统计的规范方法 最新CLSI推荐的分枝杆菌、奴卡菌、其他需氧放线菌的药敏试验规程 病原微生物的快速分子诊断进展 病原菌的分子进化研究进展 实验室的生物安全、质量控制和质量保证 厌氧菌和弯曲菌的培养、鉴定和药敏试验新进展 微生物检验与Lis系统,