嗜麦芽窄食单胞菌体外药敏试验方法评价及耐药性分析

目的评价纸片扩散法和仪器法检测嗜麦芽窄食单胞菌药敏试验的可靠性，分析嗜麦芽窄食单胞菌对常用抗菌药物的敏感性。方法琼脂稀释法、VITEK—AMS和纸片扩散法检测嗜麦芽窄食单胞菌对11种抗菌药物的敏感性。结果纸片法与琼脂稀释法检测嗜麦芽窄食单胞菌对哌拉西林-他唑巴坦的药敏结果差异有显著性；VITEK—AMS和琼脂稀释法检测嗜麦芽窄食单胞菌对阿莫西林-克拉维酸、哌拉西林-他唑巴坦、头孢他啶、复方磺胺甲唾唑的药敏结果差异有显著性；嗜麦芽窄食单胞菌对氧氟沙星、复方磺胺甲唾唑的敏感性较高。结论纸片法和VITEK—AMS用于嗜麦芽窄食单胞菌的药物敏感性检测存在缺陷；治疗嗜麦芽窄食单胞菌引起的感染可选用左氧氟沙星、复方磺胺甲噁唑。     

嗜麦芽窄食单胞菌体外药敏试验方法评价及耐药性分析

目的：评价纸片扩散法和仪器法检测嗜麦芽窄食单胞菌的药敏试验的可靠性．并分析嗜麦芽窄食单胞菌对临床常用抗菌药物的敏感性。方法：采用琼脂稀释法、VITEK—AMS和纸片扩散法检测嗜麦芽窄食单胞菌对11种抗菌药物的敏感性。结果：纸片法和琼脂稀释法检测嗜麦芽窄食单胞菌对哌拉西林／他唑巴坦的药敏结果有差异，对其余抗生素无显著性差异；VITEK—AMS和琼脂稀释法检测嗜麦芽窄食单胞菌对阿莫西林／棒酸、哌拉西林／他唑巴坦、头孢他啶、复方新诺明的药敏结果有显著性差异．对其余抗生素无显著性差异；嗜麦芽窄食单胞苗除对左旋氧氟沙星、复方磺胺甲唑有较高的敏感性外，对其余多种抗菌药物的耐药性菌较高。结论：纸片法不宜用于嗜麦芽窄食单胞菌对哌拉西林／他唑巴坦的敏感性检测；VITEK—AMS不宜用于嗜麦芽窄食单胞菌对阿莫西林／棒酸、哌拉西林／他唑巴坦、头抱他啶、复方新诺明的敏感性检测；左旋氧氟沙星、复方新诺明可做为治疗嗜麦芽窄食单胞菌引起的感染的有效药物。     

嗜麦芽窄食单胞菌体外药敏试验方法研究

目的：比较纸片扩散法和琼脂稀释法作嗜麦芽窄度食单胞菌的药敏试验。方法：采用琼脂稀释法和纸片扩散法，测定嗜麦芽窄食单胞菌对14种抗菌药物的敏感度。结果：琼脂稀释法测得嗜麦芽窄食单胞菌对头孢哌酮和头孢哌酮一舒巴坦复方制剂敏感率最高，分别为92．2％和95％；其次为复方磺胺甲噁唑、替卡西林一克拉维酸、环丙沙星和哌拉西林一三唑巴坦，细菌敏感率分别为84．3％、87．3％、76．5％和75．5％。对大多数抗菌药物的敏感率琼脂稀释法较纸片扩散法高，其差异有显著性。结论：临床微生物实验室应以稀释法进行嗜麦芽窄食单胞菌的药物敏感性试验。     

嗜麦芽窄食单胞菌耐药现状及分子流行病学特征

目的了解嗜麦芽窄食单胞菌耐药现状及分子流行病学特征。方法临床分离嗜麦芽窄食单胞菌30株,经VITEK微生物鉴定系统重新鉴定。微量肉汤稀释法检测14种抗菌药物的MIC、肠杆菌科基因间重复-致序列[(ERIC)-PCR]方法分析嗜麦芽窄食单胞菌流行特征。结果30株嗜麦芽窄食单胞菌对亚胺培南、美罗培南、头孢噻肟、氨曲南和阿米卡星高度耐药;但对头孢哌酮-舒巴坦、哌拉西林-三唑巴坦、复方磺胺甲噁唑和替卡西林-克拉维酸仍保持一定敏感性,敏感率分别为96.7%、76.7%、73.3%和60%。ERIC-PCR指纹图谱显示30株嗜麦芽窄食单胞菌由26种不同克隆构成。结论嗜麦芽窄食单胞菌对常用抗菌药物呈多重耐药,但对头孢哌酮-舒巴坦、哌拉西林-三唑巴坦、复方磺胺甲噁唑、替卡西林-克拉维酸仍保持一定敏感性。30株嗜麦芽窄食单胞菌分子流行病学显示基因型多态性。     

嗜麦芽窄食单胞菌体外药物敏感性研究

目的比较10种抗菌药物（莫西沙星、加替沙星、左氧氟沙星、环丙沙星、头孢哌酮-舒巴坦、替卡西林-克拉维酸、哌拉西林-三唑巴坦、头孢吡肟、头孢他啶、复方磺胺甲嗯唑）对临床分离嗜麦芽窄食单胞菌的体外抗菌活性。方法琼脂稀释法测定10种抗菌药物对来自北京3所医院的200株嗜麦芽窄食单胞菌的MIC值，用WHONET5．3软件进行药敏数据统计分析。结果200株菌对药物的敏感率排序为莫西沙星（84．5％）、加替沙星（79．5％）、左氧氟沙星（76％）、复方磺胺甲嗯唑（72．5％）、头孢哌酮-舒巴坦（41．5％）、替卡西林-克拉维酸（34％）、头孢他啶（23％）、环丙沙星（15％）、头孢吡肟（7％）和哌拉西林-三唑巴坦（4．5％）。结论新一代氟喹诺酮类药物如莫西沙星对嗜麦芽窄食单胞菌有较高的体外抗菌活性，是临床治疗嗜麦芽窄食单胞菌感染的较好选择。     

E试验检测42株嗜麦芽窄食单胞菌对5种抗菌药物的敏感性

目的：检测嗜麦芽窄食单胞菌对5种抗菌药物的敏感性并探讨体外试验如何更准确检测该菌耐药性。方法：用E试验检测42株临床分离菌株对替卡西林-克拉维酸、哌拉西林-三唑巴坦、头孢哌酮-舒巴坦、环丙沙星和复方磺胺甲噁唑的敏感性，分别于培养24h和48h记录结果。结果：无论培养24h还是48h。5种抗菌药物的敏感性由高到低依次为复方磺胺甲噁唑、头孢哌酮-舒巴坦、替卡西林-克拉维酸、环丙沙星和哌拉西林-三唑巴坦。药敏试验延长至48h判读结果，部分在24h敏感的菌株抑菌区内可见小的耐药菌生长。结论：嗜麦芽窄食单胞菌对所试5种抗菌药物均有不同程度耐药性，治疗时应采用联合用药。延长药敏培养时间可检出更多生长缓慢的耐药菌株。     

儿童嗜麦芽窄食单胞菌临床分离株耐药性多中心研究

目的了解儿童嗜麦芽窄食单胞菌耐药现状和临床特点,为临床预防和治疗嗜麦芽窄食单胞菌感染提供依据。方法嗜麦芽窄食单胞菌资料来源于 2019年1月1日—12月31日全国11所三级甲等儿童医院。细菌鉴定采用全自动快速生物质谱检测系统;抗菌药物敏感性试验采用全自动微生物鉴定分析仪或 K-B纸片法,结果判断采用美国临床和实验室标准化协会(CLSI)-M100判断标准,对嗜麦芽窄食单胞菌耐药性进行分析;回顾性分析249 例嗜麦芽窄食单胞菌患儿的临床特点。结果共检出嗜麦芽窄食单胞菌1 453株,分离株主要来源于痰液标本,占48.5%,其次是血液和肺泡灌洗液,分别占25.1%和5.9%。该菌对甲氧苄啶-磺胺甲■唑、左氧氟沙星、米诺环素敏感率较高,达90%以上;对头孢哌酮-舒巴坦敏感率达70.4%;对β内酰胺类抗菌药物耐药率较高,对哌拉西林-他唑巴坦的敏感率仅为44.4%。嗜麦芽窄食单胞菌感染主要见于2岁以下婴幼儿,临床表现多样,主要引起肺炎、脓毒血症等,多发生于有基础疾病、侵袭性操作、长期使用抗菌药物等高危患儿。结论儿童分离的嗜麦芽窄食单胞菌耐药率高,仅对甲氧苄啶-磺胺甲■唑、左氧氟沙星、米诺环素较敏感,临床应根据药敏结果选用抗菌药物,防止菌株产生耐药和流行。同时,临床医师应尽量减少不必要的侵袭性操作,加强抗菌药物的合理、规范使用。     

嗜麦芽窄食单胞菌135株分布及耐药性分析

目的 了解嗜麦芽窄食单胞菌的临床分布和耐药性情况,指导临床合理选用抗生素.方法 回顾性分析2008-2010年从南京鼓楼医院集团宿迁市人民医院住院患者分离的嗜麦芽窄食单胞菌的分布和药敏结果.结果 2008-2010年分离的嗜麦芽窄食单胞菌共135株,对于临床常用的抗生素敏感性从高到低依次为:米诺环素90.4%、左氧氟沙星74.1%、复方磺胺甲恶唑71.1%、头孢哌酮/舒巴坦49.6%、头孢他啶45.2%、替卡西林/克拉维酸35.6%、哌拉西林/他唑巴坦16.3%、头孢吡肟13.3%、阿米卡星12.6%、哌拉西林3.7%,所有菌株对亚胺培南和氨曲南均耐药.结论 嗜麦芽寡养单胞菌感染部位以呼吸道为主,其对大多数抗菌药物敏感度不高,临床治疗应依据药敏结果,合理选用抗生素,减少耐药菌株的产生.     

89株临床分离嗜麦芽窄食单胞菌的耐药性分析

目的：了解嗜麦芽窄食单胞菌感染的临床特征和对药物的敏感性。方法：对近2年来从各种临床标本中分离到的89株嗜麦芽窄食单胞菌进行药敏试验。结果：89株嗜麦芽窄食单胞菌感染的病例中，肺部感染占75％，尿路感染16．9％。该菌对左氧氟沙星、环丙沙星、复方磺胺甲噁唑、替卡西林-克拉维酸的敏感性较高，对亚胺培南、氨苄西林及头孢菌素等耐药性较高。结论：嗜麦芽窄食单胞菌的耐药性较高，可根椐药敏试验选用左氧氟沙星、环丙沙星、复方磺胺甲噁唑和替卡西林-克拉维酸治疗该菌引起的感染。     

嗜麦芽窄食单胞菌感染现状及耐药性探讨

目的分析嗜麦芽窄食单胞菌感染现状及耐药性,为临床医生合理用药提供科学依据。方法收集该院2006～2010年临床送检标本124例,嗜麦芽窄食单胞菌培养与鉴定按照《全国临床检验操作规程》进行,药敏试验采用纸片扩散法(K-B法)。结果 124株嗜麦芽窄食单胞菌主要分布在呼吸科(45株,36.3%)、重症监护病房(ICU)(33株,26.6%)、肿瘤病区(22株,17.7%)、内科(21株,16.9%)和外科(3株,2.4%)。嗜麦芽窄食单胞菌对14种抗菌药物药敏试验结果表明:敏感性最高的抗菌药是米诺环素,其次是替卡西林、克拉维酸、左氧氟沙星、多西环素和复方磺胺甲恶唑。环丙沙星、头孢他啶、阿米卡星、庆大霉素、哌拉西林、氨曲南和亚胺培南敏感性很低。结论嗜麦芽窄食单胞菌的耐药性已比较严重,应加强监测、预防与控制。     

In vitro susceptibility of Stenotrophomonas maltophilia isolates: comparison of disc diffusion, Etest and agar dilution methods

The disc diffusion, Etest and agar dilution techniques were compared to evaluate the antimicrobial susceptibility profile of 70 Stenotrophomonas maltophilia isolates to seven antimicrobial agents. The S. maltophilia isolates were consecutively collected from May 2000 to May 2002 from individual patients, who were hospitalized in a private Brazilian hospital. The antimicrobial susceptibility tests were carried out and interpreted according to the National Committee for Clinical Laboratory Standards (NCCLS) recommendations. The Etest was carried out according to the manufacturer's instructions. There was good agreement among the distinct susceptibility testing results for chloramphenicol, doxycycline, gatifloxacin, trimethoprim-sulfamethoxazole and ticarcillin-clavulanate, suggesting that the disc diffusion and Etest methods are reliable for testing this group of antimicrobials against S. maltophilia. In contrast, a weak correlation was found between the disc diffusion and agar dilution techniques for testing polymyxin B and colistin with unacceptable very major error rates (18.1% and 22.7% for polymyxin B and colistin, respectively). Trimethoprim- sulfamethoxazole (MIC50, 0.06 mg/L; 98.5% susceptible) and gatifloxacin (MIC50, 0.12 mg/L; 98.5% susceptible) were the most potent antimicrobial agents tested against S. maltophilia isolates. In contrast, the worst in vitro activity was found for ticarcillin-clavulanate (MIC50, 16 mg/L; 59.1% susceptible). Although our results confirm that trimethoprim-sulfamethoxazole, gatifloxacin and doxycycline have an excellent in vitro activity against S. maltophilia, further clinical studies are necessary to evaluate the clinical efficacy of these compounds for the treatment of S. maltophilia infections, since no randomized controlled trials have been carried out and no correlation between the clinical response and susceptibility testing results has been reported.     

Antimicrobial susceptibility of community-acquired respiratory tract pathogens in the UK during 2002/3 determined locally and centrally by BSAC methods

OBJECTIVES: To determine the antimicrobial susceptibility of Haemophilus influenzae, Moraxella catarrhalis and Streptococcus pneumoniae causing community-acquired lower respiratory tract infection in the UK during 2002/2003 and to compare susceptibilities determined locally by disc diffusion with agar dilution MICs determined at a central laboratory. METHODS: H. influenzae, M. catarrhalis and S. pneumoniae were isolated in 30 laboratories and susceptibility determined locally by the BSAC standardized disc diffusion method. At a central laboratory, isolates were re-identified, tested for beta-lactamase production (H. influenzae and M. catarrhalis only) and MICs determined using the BSAC agar dilution method. RESULTS: Five hundred and eighty-one H. influenzae, 269 M. catarrhalis and 519 S. pneumoniae were collected. Over 93% of M. catarrhalis and nearly 15% of H. influenzae were beta-lactamase positive rendering these sub-populations resistant to aminopenicillins. Overall, the antibacterial susceptibility rates for the isolates were high. However, macrolides showed poor activity against H. influenzae (0.86-1.38% susceptible by disc or MIC methods) and, compared with other antimicrobials, against S. pneumoniae (approximately 88% susceptible). Between 84% and 95% of H. influenzae, M. catarrhalis and S. pneumoniae were susceptible to cefuroxime but all isolates were susceptible to cefotaxime. Eighty-five percent of H. influenzae were susceptible to trimethoprim. The fluoroquinolones were very active against the isolates, with moxifloxacin showing lower MICs than levofloxacin against S. pneumoniae. Susceptibility determined locally by disc diffusion was in general agreement with that determined centrally by agar dilution MIC testing. However, there was one inconsistency with H. influenzae where disc diffusion indicated 22.9% and 46.8% resistance to clarithromycin and erythromycin, respectively but by MIC, only 0.9% and 6.9% were resistant, respectively. CONCLUSIONS: Rates of resistance within community-acquired respiratory tract isolates were relatively low in the UK, in agreement with other studies. Moxifloxacin was the only antibacterial with over 99% isolates susceptible for each of the three pathogens investigated where breakpoints are available. The comparison between disc susceptibility testing and MIC determination using BSAC methods indicated generally good correlation but has highlighted a methodological problem with macrolides against H. influenzae in particular.     

头孢哌酮/舒巴坦对ICU常见革兰阴性杆菌抗菌活性的研究

目的 了解头孢哌酮/舒巴坦对临床常见革兰阴性杆菌的抗菌活件,比较不同浓度的头孢哌酮/舒巴坦纸片药敏试验结果的差异.方法 分离自浙江大学医学院附属第二医院、浙江省人民医院、杭州市第三人民医院和杭州市中医院的临床常见381株革兰阴性杆菌用头孢哌酮/舒巴坦含量75/75(150)和头孢哌酮/舒巴坦含量75/30(105)的药敏纸片进行K-B法药敏试验,同时用标准的琼脂稀释法检测头孢哌酮/舒巴坦的最低抑菌浓度(MIC),并采用WHONET 5.4软什和SPSS统计软件对实验结果进行分析.结果 头孢哌酮/舒巴坦105浓度和150浓度纸片法检测大肠埃希菌、肺炎克雷伯菌、铜绿假单胞菌和鲍曼不动杆菌,两种浓度纸片的符合率分别为:26.3%,79.2%,83.7%和33%,用SPSS 10.0统计k-related samples检验,P＜0.05;105浓度纸片法和琼脂稀释法针对以上4种菌的比对符合率分别为77.8%,89.6%,70.9%和77%;150浓度纸片法和琼脂稀释法的比对符合率分别为:27.3%,79.2%,61.6%和30%,两种浓度纸片法和稀释法的误差率比较,150纸片的假敏感和假中介要高于105纸片.结论 105浓度纸片法的结果更接近于作为金标准的稀释法,而目前临床药敏实验使用的150浓度的纸片法提高了细菌的敏感性.     

Comparison of different antimicrobial susceptibility testing methods for Stenotrophomonas maltophilia and results of synergy testing

Accurate determination of resistance is important to ensure appropriate antimicrobial therapy in Stenotrophomonas maltophilia infections. This study was undertaken to evaluate the susceptibility results obtained by disc diffusion, E-test, Phoenix system, and reference agar dilution method and also to evaluate the in vitro activity of various antimicrobial combinations against multidrug-resistant S. maltophilia. Susceptibilities to several antimicrobial agents were determined by agar dilution, disc diffusion, and E-test according to the US Clinical Laboratory and Standards Institute (CLSI) guidelines. Results were also evaluated in the in Phoenix system for available agents. Twelve different antibiotic combinations were tested for synergy by the E-test method. Most synergic combinations were confirmed by microdilution checkerboard assay. Tigecycline, trimethoprim/sulfamethoxazole (TMP–SMX) and doxycycline were the most effective drugs against S. maltophilia. Poorest agreement was determined by disc diffusion and E-test against ticarcillin/clavulanate and ciprofloxacin (κ < 0.4), by disc diffusion against colistin (κ < 0.4), and by the Phoenix system against piperacillin/tazobactam (κ < 0.4). Based on these data, disc diffusion seems to be unreliable for ticarcillin/clavulanate, ciprofloxacin, and colistin; E-test for ticarcillin/clavulanate and ciprofloxacin; and the Phoenix system for piperacillin/tazobactam for S. maltophilia susceptibility testing. Synergistic activity was detected predominantly with TMP–SMX + ticarcillin/clavulanate and TMP–SMX + ceftazidime. TMP–SMX + ceftazidime synergy was also supported by the checkerboard method. However, TMP–SMX + ticarcillin/clavulanate combination revealed indifferent effect by the checkerboard assay. As ticarcillin/clavulanate and ciprofloxacin E-test results were beyond the acceptable correlation limits, synergy testing performed with these agents was considered as unreliable. Further studies are required to standardize susceptibility testing, especially for colistin, ticarcillin/clavulanate, and ciprofloxacin for S. maltophilia. TMP–SMX-containing drug combinations seemed to be more synergistic on multidrug-resistant S. maltophilia; however, these results merit further evaluation.     

Pitfalls of polymyxin antimicrobial susceptibility testing of Pseudomonas aeruginosa isolated from cystic fibrosis patients

OBJECTIVES AND METHODS: With their potent activity against Gram-negative bacteria, the polymyxins are important alternative antibiotics for cystic fibrosis (CF) patients. A retrospective evaluation of polymyxin activity against 6001 Pseudomonas aeruginosa, 150 Achromobacter xylosoxidans and 506 Stenotrophomonas maltophilia CF isolates was initiated. In addition, we looked at how polymyxin susceptibility testing was affected by the testing method (agar dilution versus microdilution), the agent (polymyxin E versus polymyxin B), incubation time (24 h versus 48 h) and by different interpretative criteria (German DIN, French FSM, British BSAC). RESULTS: Polymyxin B exhibited reasonable activity against P. aeruginosa (MIC(90)< or =2 mg/L), whereas it was less active against A. xylosoxidans (MIC(90)< or =16 mg/L) and S. maltophilia (MIC(90)< or =16 mg/L). During 2000-2002, polymyxin B resistance in P. aeruginosa, S. maltophilia and A. xylosoxidans was found to be 6.7%, 17.0% and 29.9% (corresponding to 12.4%, 20.7% and 35.4% of infected patients), respectively. When the agar dilution method was used, polymyxin E exhibited higher MICs than polymyxin B. The microdilution method produced lower polymyxin MICs than the agar dilution method. Therefore, the microdilution MICs after prolonged incubation (48 h) and the agar dilution MICs of polymyxin B correlated best (AUC of 0.93, r(2) of 0.44 and s of 0.83). CONCLUSIONS: Polymyxin resistance among common CF pathogens is not rare, thus underlining the necessity of accurate susceptibility testing. When compared with the agar dilution method, it was found that the microdilution method is a valid, rapid and cost effective alternative for the determination of polymyxin activity. The performance of the microdilution method was most reliable after prolonged incubation (48 h) at a susceptibility breakpoint of < or =4 mg/L according to the BSAC guidelines (specificity 91%, sensitivity 89%, 1.5% very major errors).     

The in-vitro susceptibility of the Bacteroides fragilis group to amoxycillin-clavulanic acid

The susceptibility to amoxycillin-clavulanic acid of 150 strains belonging to the Bacteroides fragilis group was tested by both disc diffusion and agar dilution methods. On the basis of minimum inhibitory concentrations (MICs), at least 99% of the isolates were sensitive to this agent. However, problems encountered with the disc diffusion method suggest that at present it is unsatisfactory for assessing the in-vitro activity of amoxycillin-clavulanic acid against this group of organisms.     

嗜麦芽窄食单胞菌的耐药性分析

目的分析临床分离的嗜麦芽窄食单胞菌的耐药性及MIC分布，为嗜麦芽窄食单胞菌感染临床合理应用抗菌药物提供依据。方法采用琼脂二倍稀释法测定四川大学华西医院收集到的103株临床分离的嗜麦芽窄食单胞菌对8种抗菌药物的MIC。结果103株嗜麦芽窄食单胞菌对多种常用抗菌药物呈现多重耐药，但对复方磺胺甲嘌唑、替卡西林一克拉维酸、环丙沙星、左氧氟沙星和加替沙星的耐药率较低，分别为34．0％、16．5％、26．2％、5．8％和4．9％。结论对嗜麦芽窄食单胞菌引起的感染应尽早进行病原学检查，并在其药物敏感试验结果指导下选用合适的抗菌药物。     

Antibiotic Susceptibility Testing of Bacteroides

Seventy Bacteroides strains isolated from clinical materials were tested in vitro against nine antibiotics by means of modified disc diffusion and agar dilution tests. Correlating the agar dilution susceptibility with the concentrations achievable in serum for each drug tested, we found that at least 90% of the strains were susceptible to clindamycin, chloramphenicol, carbenicillin, and lincomycin. Only 40% were susceptible to tetracycline. Except for tetracycline and chloramphenicol, the disc diffusion technique exhibited inadequate predictive value in terms of "susceptibility" and "resistance" for the Bacteroides strains tested.     

头孢哌酮-舒巴坦药敏纸片中舒巴坦量对药敏结果的影响

目的 探讨头孢哌酮-舒巴坦药敏纸片中舒巴坦量对药敏结果 的影响.方法 用琼脂稀释法检测头孢哌酮、头孢哌酮-舒巴坦(2:1)和头孢哌酮-舒巴坦(1:1)3组药对临床分离的534株革兰阴性杆菌的MIC值;用纸片扩散法检测头孢哌酮、头孢哌酮-舒巴坦75/30μg和75/75μg 3种纸片对此534株菌的抑菌环直径;分析MIC结果 之间、纸片扩散法之间,以及2种药敏方法 之间的结果 是否有差异.结果 经琼脂稀释法检测头孢哌酮、头孢哌酮-舒巴坦(2:1)和(1:1)MIC_(50)分别为:32、16、16μg/ml,MIC_(90)分别为≥256,128,64μg/ml,Wilcoxon秩和检验两种药量配比MIC结果 无统计学差异(Z=-0.248,P=0.804);头孢哌酮-舒巴坦75/30μg药敏纸片(75/30纸片)检测的敏感率(S%)、耐药率(R%)和中介率(I%)分别为55.3%、24.5%和20.2%,与琼脂稀释法结果 相似.头孢哌酮-舒巴坦75/75μg(75/75纸片)敏感率、耐药率和中介率分别为72.5%、12.4%和15.1%,比75/30纸片检测的总敏感率高17.2%,对75/30纸片及75/75纸片测所有菌株的2组抑菌环直径进行配对t检验(t=21.613,P＜0.01),但这种差异只来自于CISI规定检测出的产ESBL菌株、鲍曼不动杆菌和未经ESBL检测的其他肠杆菌科菌株;而对铜绿假单胞菌、嗜麦芽窄食单胞菌和ESBL阴性菌株的敏感率或耐药率差异无统计学意义.结论 头孢哌酮-舒巴坦(2:1)和(1:1)琼脂稀释法药敏结果 及75/30μg纸片法药敏结果 无差异.当使用75/75μg药敏纸片报告产ESBL菌株、鲍曼不动杆菌和其他肠杆菌科菌株的药敏结果 时,应注明舒巴坦的含量.     

Methicillin resistance in staphylococci: an evaluation of conditions for detection

Ninety-four strains of coagulase positive staphylococci and 73 strains of coagulase negative staphylococci were tested for their susceptibility to methicillin, using agar dilution and disc diffusion techniques with Diagnostic Sensitivity Test agar (DST) and DST supplemented with salt, incubated at 30 degrees C and 37 degrees C. Disc diffusion on salt-incorporated DST at 30 degrees C was most reliable for detecting methicillin resistance in both types of staphylococci. The agar dilution methods were particularly poor for detecting resistance with coagulase negative staphylococci. The simultaneous testing of coagulase positive and negative staphylococci by this method indicated the need for both DST and salt-incorporated DST agar plates, incubated at 30 degrees C. However, sensitive strains should still be tested by disc diffusion for confirmation.