替加环素对碳青霉烯类耐药鲍曼醋酸钙复合不动杆菌的体外抗菌活性

目的 测定替加环素对碳青霉烯类耐药鲍曼醋酸钙复合不动杆菌的体外抗菌活性。方法 收集2013年12月至2014年2月本院分离的碳青霉烯类耐药鲍曼醋酸钙复合不动杆菌,采用MTS法检测替加环素MIC值,折点采用美国食品药物管理局(FDA)公布的判定标准。结果 61株碳青霉烯类耐药鲍曼醋酸钙复合不动杆菌对临床常用抗菌药物具有极高的耐药率,替加环素的灵敏度为80.3%,中介率为19.7%,无耐药菌株。MIC90为3μg/mL,而MIC50为2μg/mL。结论 替加环素对于本院分离的碳青霉烯类耐药鲍曼醋酸钙复合不动杆菌有较好的体外抗菌活性。     

多重耐药鲍曼不动杆菌对替加环素等15种抗菌药物的耐药性分析

摘要:目的：分析多重耐药鲍曼不动杆菌对替加环素等15种抗菌药物的耐药性。 方法：常规培养和分离菌株,经Vitek-32全自动微生物分析仪及配套GNI⁺和GNS药敏卡进行菌株鉴定和药敏试验,替加环素、头孢哌酮/舒巴坦的药敏试验采用K-B法。 结果:100株多重耐药鲍曼不动杆菌对替加环素的敏感率为95.0%,其中70 株耐亚胺培南的鲍曼不动杆菌对替加环素的敏感率为97.1%(68/70);对其余14种抗菌药物100%耐药的有5种;除对头孢哌酮/舒巴坦耐药率较低（20.0%）外,对其余药物耐药率都在70%以上。 结论:替加环素对多重耐药的鲍曼不动杆菌有较强的敏感性。     

染色体微阵列分析是发育迟缓和先天畸形患者的首选检测

摘要:目的：分析多重耐药鲍曼不动杆菌对替加环素等15种抗菌药物的耐药性。 方法：常规培养和分离菌株,经Vitek-32全自动微生物分析仪及配套GNI⁺和GNS药敏卡进行菌株鉴定和药敏试验,替加环素、头孢哌酮/舒巴坦的药敏试验采用K-B法。 结果:100株多重耐药鲍曼不动杆菌对替加环素的敏感率为95.0%,其中70 株耐亚胺培南的鲍曼不动杆菌对替加环素的敏感率为97.1%(68/70);对其余14种抗菌药物100%耐药的有5种;除对头孢哌酮/舒巴坦耐药率较低（20.0%）外,对其余药物耐药率都在70%以上。 结论:替加环素对多重耐药的鲍曼不动杆菌有较强的敏感性。     

MALDI-TOF MS对醋酸钙鲍曼不动杆菌复合群菌种鉴定效果的分析

目的评估基质辅助激光解吸/电离飞行时间质谱(MALDI-TOF MS)技术对醋酸钙不动杆菌-鲍曼不动杆菌复合群内菌种的鉴定能力。方法收集2018年1月至2020年3月经Vitek 2全自动微生物鉴定仪鉴定为醋酸钙不动杆菌-鲍曼不动杆菌复合群的菌株280株,用Vitek MALDI-TOF MS(V3.2)鉴定并用gyr B基因测序验证,比较复合群内不同种间的耐药性差异。结果 280株醋酸钙不动杆菌-鲍曼不动杆菌复合群经Vitek MALDI-TOF MS鉴定,结果为鲍曼不动杆菌251株、医院不动杆菌15株和皮特不动杆菌14株。质谱鉴定结果与基因测序结果符合率为100%。鲍曼不动杆菌对多种抗菌药物均表现为高度耐药,耐药率多在60%以上,医院不动杆菌和皮特不动杆菌对多种抗菌药物呈现高度敏感。除了对阿米卡星、米诺环素、复方磺胺甲噁唑外,鲍曼不动杆菌对各种检测药物的耐药性显著高于医院不动杆菌和皮特不动杆菌,差异有统计学意义(P0.05);医院不动杆菌和皮特不动杆菌在各种检测药物耐药率上差异无统计学意义(P 0.05)。结论 Vitek MALDI-TOF MS3.2版本可实现醋酸钙不动杆菌-鲍曼不动杆菌复合群不同种的鉴定;醋酸钙不动杆菌-鲍曼不动杆菌复合群不同种的药敏结果存在差异性。     

烧伤病房革兰阴性多重耐药菌耐药性分析

目的分析烧伤病房革兰阴性多重耐药菌的病原菌分布及耐药性,为临床合理应用抗生素提供依据,并探讨多重耐药菌的防控策略。方法应用VITEK2-compact全自动微生物鉴定及药敏分析系统对临沂市人民医院烧伤整形科2012年1月至2014年1月送检标本分离的菌株进行菌种鉴定,采用K-B纸片扩散法进行药敏试验,统计分析革兰阴性多重耐药菌的分布情况及其对抗菌药物的耐药情况。结果共检出130株革兰阴性多重耐药菌,创面分泌物为其主要标本来源,占81.54%,其次为痰液,占12.30%。菌株分布以鲍曼不动杆菌和大肠埃希菌为主,分别占38.46%(50/130)、29.23%(38/130)。大肠埃希菌和肺炎克雷伯菌产超广谱β-内酰胺酶(ESBLs)菌株分离率为89.47%(34/38)、87.50%(14/16)。耐碳青霉烯类抗生素鲍曼不动杆菌(CR-AB)对除替加环素、左氧氟沙星之外的所有测试抗菌药物均呈现高度耐药,耐药率在90%~100%之间;肺炎克雷伯菌和大肠埃希菌对碳青霉烯类抗生素、含酶抑制剂的复合制剂、替加环素耐药率均小于20%,而对氨基糖苷类、第三代头孢菌素类、喹诺酮类抗生素耐药率较高。铜绿假单胞菌和阴沟肠杆菌仅对丁胺卡那霉素有较高敏感性。结论革兰阴性多重耐药菌对常用抗菌药物表现出较高耐药性,应及时制定防控策略,缓解细菌耐药性。     

耐碳青霉烯类药物肺炎克雷伯菌和鲍曼不动杆菌对替加环素的敏感性分析

目的 分析耐碳青霉烯类药物肺炎克雷伯菌和鲍曼不动杆菌对替加环素的敏感性,为临床控制耐碳青霉烯类药物病菌繁殖提供理论依据。方法 收集2016年12月～2017年12月本院住院患者送检标本中分离出来的耐碳青霉烯类药物肺炎克雷伯菌112株和耐碳青霉烯类药物鲍曼不动杆菌98株,比较耐碳青霉烯类药物肺炎克雷伯菌和鲍曼不动杆菌对各类抗菌药物的耐药性差异。结果 耐碳青霉烯类药物的肺炎克雷伯菌和鲍曼不动杆菌几乎对所有抗菌类药物都有较强的耐药性;耐碳青霉烯类药物肺炎克雷伯菌对替加霉素的敏感菌数为97株,占86.61%,而耐碳青霉烯类药物鲍曼不动杆菌对替加霉素的敏感菌数为68株,占69.39%,替加环素对肺炎克雷伯菌的敏感性明显优于鲍曼不动杆菌,差异有统计学意义(χ~2=14.034,P=0.001);当MIC为4 mg/L时耐碳青霉烯类肺炎克雷伯菌的敏感率为100.00%,而碳青霉烯类鲍曼不动杆菌敏感率为71.21%,替加环素对两类菌体外敏感率分布差异有统计学意义(χ~2=18.488,P=0.002)。结论 耐碳青霉烯类药物肺炎克雷伯菌对替加环素的敏感性明显高于耐碳青霉烯类药物鲍曼不动杆菌,所以临床上采用替加环素可以有效控制耐碳青霉烯类肺炎克雷伯菌。     

某院革兰阴性杆菌耐药性监测及其临床意义

目的 分析该院2010年度临床分离革兰阴性杆菌的耐药状况,为临床合理使用抗菌药物提供依据.方法 常规方法培养分离医院内感染病原菌,并应用全自动细菌鉴定分析仪鉴定到种,采用WHONET5.4软件进行数据统计分析.结果 该院共分离出革兰阴性杆菌445株,其中大肠埃希菌111株,铜绿假单胞菌109株,鲍曼不动杆菌84株,肺炎克雷伯菌69株.药敏监测结果显示,大肠埃希菌和肺炎克雷伯菌对哌拉西林和氨苄西林耐药,对美罗培南、亚胺培南、厄他培南、替加环素敏感.铜绿假单胞菌对头孢替坦、复方新诺明、氨苄西林耐药,对阿米阿星和他唑巴坦较为敏感,鲍曼不动杆菌对头孢唑林、头孢西丁、头孢呋辛钠、呋喃妥因耐药,对美罗培南敏感.结论 革兰阴性杆菌对多种抗菌药物的耐药率呈现上升趋势,临床微生物实验室应加强对多重耐药菌的监测,为临床正确合理使用抗菌药物提供依据.     

替加环素对ICU多重耐药革兰阴性菌体外抗菌活性研究

目的研究替加环素对重症监护病房(ICU)分离的多重耐药革兰阴性杆菌的体外抗菌活性,为临床合理用药提供参考。方法通过回顾性分析方法,对某医院ICU送检标本分离的革兰阴性菌体外抗替加环素活性进行调查与分析。结果从ICU分离的革兰阴性病原菌中,选择耐碳青霉烯类药物的大肠埃希菌(11株)、肺炎克雷伯菌(60株)和鲍曼不动杆菌(118株)进行替加环素抗性试验,结果显示对替加环素的敏感率依次为100.0%、93.3%和89.0%。结论替加环素对ICU分离的多重耐药革兰阴性杆菌具有很好的体外抗菌活性,可作为临床用药选择依据。     

三种方法评估替加环素对多重耐药鲍曼不动杆菌体外药敏结果分析

目的　比较3 种药敏检测方法检测替加环素对多重耐药鲍曼不动杆菌敏感性的差异。方法　收集2018 年临床 分离耐碳青霉烯类鲍曼不动杆菌60 株,采用MIC Test Strip（MTS）法、VITEK-2 法、纸片扩散法分别检测替加环素对 耐碳青霉烯类鲍曼不动杆菌的敏感性。结果　按照FDA 标准,以MTS 法为参考,VITEK-2 法的一致率较高,纸片扩 散法的一致率较低。Vitek-2 法的MIC 值比MTS 法的MIC 值低1 ~ 2 个稀释度,利用MTS 法检测替加环素对耐碳青霉 烯鲍曼不动杆菌的耐药率达到23.3%,出现耐药株。结论　对于耐碳青霉烯类鲍曼不动杆菌,Vitek-2 法和纸片扩散法 均不适合检测替加环素的敏感性,不能作为常规方法,需用MTS 法确认。     

替加环素等14种抗菌药物对多重耐药菌的体外抗菌活性研究

目的 评价替加环素等14种抗菌药物对多重耐药细菌的体外抗菌活性.方法 采用微量肉汤稀释法测定替加环素对临床分离的214株多重耐药细菌(MRSA、肠球菌属细菌、鲍曼不动杆菌、产ESBLs大肠埃希菌、产ESBLs肺炎克雷伯菌和肠杆菌属细菌)的MIC,并与其他13种抗菌药物进行比较.数据分析采用WHONET 5.4软件.结果 多重耐药的MRSA对替加环素、万古霉素和利奈唑胺的敏感性均为100%.多重耐药的肠球菌属(粪肠球菌和屎肠球菌)对替加环素和利奈唑胺的敏感率均为100%,万古霉素敏感率为93.1%,2株万古霉素耐药的多重耐药屎肠球菌对替加环素和利奈唑胺均呈敏感,MIC90值分别为0.064 mg/L和1 mg/L.37株多重耐药鲍曼不动杆菌对替加环素的敏感率为97.3%,MIC90值为2 mg/L,其中16株耐美罗培南的鲍曼不动杆菌对替加环素的敏感率仍为100%,MIC90值为2 mg/L.产ESBLs大肠埃希菌和肺炎克雷伯菌对替加环素和美罗培南的敏感率均为100%,但替加环素的MIC90值均高于美罗培南.多重耐药的肠杆菌属细菌(阴沟肠杆菌和产气肠杆菌)对替加环素的敏感率为86.5%,MIC90值为4 mg/L.结论 替加环素对多重耐药的常见需氧革兰阳性球菌和革兰阴性杆菌均有良好的体外抗菌活性.     

Trends in the susceptibility of clinically important resistant bacteria to tigecycline: results from the Tigecycline In Vitro Surveillance in Taiwan study, 2006 to 2010

The Tigecycline In Vitro Surveillance in Taiwan (TIST) study, a nationwide, prospective surveillance during 2006 to 2010, collected a total of 7,793 clinical isolates, including methicillin-resistant Staphylococcus aureus (MRSA) (n = 1,834), penicillin-resistant Streptococcus pneumoniae (PRSP) (n = 423), vancomycin-resistant enterococci (VRE) (n = 219), extended-spectrum β-lactamase (ESBL)-producing Escherichia coli (n = 1,141), ESBL-producing Klebsiella pneumoniae (n = 1,330), Acinetobacter baumannii (n = 1,645), and Stenotrophomonas maltophilia (n = 903), from different specimens from 20 different hospitals in Taiwan. MICs of tigecycline were determined following the criteria of the U.S. Food and Drug Administration (FDA) and the European Committee on Antimicrobial Susceptibility Testing (EUCAST-2011). Among drug-resistant Gram-positive pathogens, all of the PRSP isolates were susceptible to tigecycline (MIC(90), 0.03 μg/ml), and only one MRSA isolate (MIC(90), 0.5 μg/ml) and three VRE isolates (MIC(90), 0.125 μg/ml) were nonsusceptible to tigecycline. Among the Gram-negative bacteria, the tigecycline susceptibility rates were 99.65% for ESBL-producing E. coli (MIC(90), 0.5 μg/ml) and 96.32% for ESBL-producing K. pneumoniae (MIC(90), 2 μg/ml) when interpreted by FDA criteria but were 98.7% and 85.8%, respectively, when interpreted by EUCAST-2011 criteria. The susceptibility rate for A. baumannii (MIC(90), 4 μg/ml) decreased from 80.9% in 2006 to 55.3% in 2009 but increased to 73.4% in 2010. A bimodal MIC distribution was found among carbapenem-susceptible A. baumannii isolates, and a unimodal MIC distribution was found among carbapenem-nonsusceptible A. baumannii isolates. In Taiwan, tigecycline continues to have excellent in vitro activity against several major clinically important drug-resistant bacteria, with the exception of A. baumannii.     

AdeABC multidrug efflux pump is associated with decreased susceptibility to tigecycline in Acinetobacter calcoaceticus-Acinetobacter baumannii complex

OBJECTIVES: To investigate the role of the AdeABC multidrug efflux pump in the decreased susceptibility of clinical isolates of Acinetobacter calcoaceticus-Acinetobacter baumannii complex to tigecycline. METHODS: Gene expression was analysed by Taqman RT-PCR. A single cross-over achieved insertional inactivation of the adeB gene with a suicide plasmid construct carrying an adeB fragment obtained by PCR. Analysis of the adeRS locus was performed by PCR and sequencing. Ribotyping was performed with the RiboPrinter system. MICs were determined by Etest. RESULTS: Expression analysis revealed constitutive overexpression of adeABC in less-susceptible clinical isolates G5139 and G5140 (tigecycline MIC=4 mg/L) when compared with the isogenic clinical isolates G4904 and G5141 (MIC=1.5 mg/L). Insertional mutants GC7945 (adeB knockout in G5139) and GC7951 (adeB knockout in G5140) were obtained, which resulted in tigecycline MICs of 0.5 mg/L. As reported previously, the expression of adeABC is regulated by the two-component signalling system encoded by the adeR and adeS genes. PCR and sequencing analyses revealed an insertion of an IS(ABA-1) element in the adeS gene of G5139 and G5140. CONCLUSIONS: The results of this study suggest that decreased susceptibility to tigecycline in the A. calcoaceticus-A. baumannii complex is associated with the overexpression of the AdeABC multidrug efflux pump.     

High tigecycline resistance in multidrug-resistant Acinetobacter baumannii

OBJECTIVES: Multidrug-resistant (MDR) Acinetobacter baumannii is increasing in our hospital and worldwide, raising the necessity of finding effective therapies. We aimed to evaluate the in vitro activity of tigecycline against MDR A. baumannii clones isolated before tigecycline was used in our institution. METHODS: Eighty-two unique patient clinical isolates of multidrug-resistant A. baumannii collected in 2003 were studied. Species identification and antibiotic susceptibilities were determined by Vitek-2. Tigecycline MIC was determined by Etest. Clonal relatedness was determined by PFGE. RESULTS: MDR A. baumannii possessed 19 different pulsotypes. Sixty-six percent of the isolates were resistant to tigecycline, 12% were intermediate and 22% were susceptible. The MIC(50) and MIC(90) of tigecycline were 16 and 32 mg/L, respectively, with a wide MIC range of 1-128 mg/L. Variability in MIC of tigecycline was evident between and within the same pulsotype. CONCLUSIONS: We report here high resistance rates to tigecycline, and higher than previously described MICs, in multiple clones of MDR A. baumannii. As tigecycline represents a new treatment choice for infections caused by A. baumannii, these findings are worrisome.     

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.     

Agreement assessment of tigecycline susceptibilities determined by the disk diffusion and broth microdilution methods among commonly encountered resistant bacterial isolates: results from the Tigecycline In Vitro Surveillance in Taiwan (TIST) study, 2008 to 2010

The Tigecycline In Vitro Surveillance in Taiwan (TIST) study, initiated in 2006, is a nationwide surveillance program designed to longitudinally monitor the in vitro activity of tigecycline against commonly encountered drug-resistant bacteria. This study compared the in vitro activity of tigecycline against 3,014 isolates of clinically important drug-resistant bacteria using the standard broth microdilution and disk diffusion methods. Species studied included methicillin-resistant Staphylococcus aureus (MRSA; n = 759), vancomycin-resistant Enterococcus faecium (VRE; n = 191), extended-spectrum β-lactamase (ESBL)-producing Escherichia coli (n = 602), ESBL-producing Klebsiella pneumoniae (n = 736), and Acinetobacter baumannii (n = 726) that had been collected from patients treated between 2008 and 2010 at 20 hospitals in Taiwan. MICs and inhibition zone diameters were interpreted according to the currently recommended U.S. Food and Drug Administration (FDA) criteria and the European Committee on Antimicrobial Susceptibility Testing (EUCAST) criteria. The MIC(90) values of tigecycline against MRSA, VRE, ESBL-producing E. coli, ESBL-producing K. pneumoniae, and A. baumannii were 0.5, 0.125, 0.5, 2, and 8 μg/ml, respectively. The total error rates between the two methods using the FDA criteria were high: 38.4% for ESBL-producing K. pneumoniae and 33.8% for A. baumannii. Using the EUCAST criteria, the total error rate was also high (54.6%) for A. baumannii isolates. The total error rates between these two methods were <5% for MRSA, VRE, and ESBL-producing E. coli. For routine susceptibility testing of ESBL-producing K. pneumoniae and A. baumannii against tigecycline, the broth microdilution method should be used because of the poor correlation of results between these two methods.     

多重耐药鲍曼不动杆菌对替加环素耐药状况分析

目的 了解多重耐药鲍曼不动杆菌对临床常用抗生素及新药替加环素的耐药状况.方法 收集2008-2009年浙江省4所教学医院的602株临床分离鲍曼不动杆菌,采用琼脂稀释法检测其对13种临床常用抗生素的敏感性,以及对多黏菌素B和替加环素的敏感性.同时,采用PFGE技术对24株多重耐药鲍曼不动杆菌进行同源性分析,以确定菌株间的亲缘关系.结果 浙江省4家教学医院2008-2009年分离的鲍曼不动杆菌主要来自于呼吸道标本,2009年达到277株(86.0%),血液标本数量从2008年的15株(5.4%)下降到2009年的5株(1.5%),而其他标本无明显变化.鲍曼不动杆菌对临床常用的13种抗生素均有不同程度的耐药,耐药率35.0%～85.0%.与2008年相比,除左氧氟沙星和妥布霉素耐药率分别下降0.9%和9.0%以外,2009年其余抗生素耐药率均有不同程度地上升,头孢曲松和头孢吡肟耐药率增加了近10.0%,对碳青霉烯类抗生素亚胺培南和美罗培南的耐药率分别达到74.2%(239/602)和70.8%(228/602).鲍曼不动杆菌对替加环素显示了很高的耐药率,耐药率达到78.9%(475/602),而多黏菌素B耐药率仅为3.7%(22/602).PFGE分型显示2008-2009年24株鲍曼不动杆菌有6个克隆型,其中A型最常见,占50%.结论 鲍曼不动杆菌对替加环素的耐药加大了院内感染控制的难度,临床应加强控制,防止多重耐药菌的传播.

Abstract：

Objective To investigate the resistance of Acinetobacter baumannii to clinical common antibiotics and new drug tigecycline. Methods Six hundred and two Acinetobacter baumannii isolates were collected from 2008 to 2009 in four teaching hospitals in Zhejiang province. Agar dilution method was used to detect the resistance of 13 clinical commom antibiotics, polymyxin B and tigecycline. Homology analysis of 24 multi-drug resistant Acinetobacter baumannii strains was used to investigate the relationship of each strain with the method of pulsed field gel electrophoresis. Results From 2008 to 2009, the Acinetobacter baumannii isolates of four teaching hospitals in Zhejiang province were mainly isolated from respiratory specimens with the number of 277 (86.0%) strains in 2009, the number of blood samples decreased from 15 (5.4%) strains in 2008 to 5 ( 1.5% ) strains in 2009, and there were no obvious change in other specimens. Acinetobacter baumannii strains were resistant to 13 clinical common antibiotics at different degree, fluctuated from 35.0% to 85.0%. Compared with the resistance in 2008, levofloxacin and tobramyxin decreased 0. 9% and 9.0% in 2009, respectively. However, the resistance of other antibiotics increased at different degree, the resistance of ceftriaxone and cefepime increased about 10.0%, and the resistance of imipenem and meropenem increased to 74.2% (239/602) and 70.8% (228/602) in 2009,respectively. Acinetobacter baumannii showed high resistance to tigecycline with the percent of 78.9% (475/602), while it was only 3.7% (22/602) for polymyxin B. There were six cloning types among the 24 Acinetobacter baumannii isolates, and the most common type was type A with the percent of 50%.Conclusions The resistance of tigecycline makes the situation of nosocomial infectious more serious. It is necessary to control the transmission of multi-drug resistant Acinetobacter baumannii immediately.     

多重耐药鲍曼不动杆菌对替加环素耐药状况分析

目的 了解多重耐药鲍曼不动杆菌对临床常用抗生素及新药替加环素的耐药状况.方法 收集2008-2009年浙江省4所教学医院的602株临床分离鲍曼不动杆菌,采用琼脂稀释法检测其对13种临床常用抗生素的敏感性,以及对多黏菌素B和替加环素的敏感性.同时,采用PFGE技术对24株多重耐药鲍曼不动杆菌进行同源性分析,以确定菌株间的亲缘关系.结果 浙江省4家教学医院2008-2009年分离的鲍曼不动杆菌主要来自于呼吸道标本,2009年达到277株(86.0%),血液标本数量从2008年的15株(5.4%)下降到2009年的5株(1.5%),而其他标本无明显变化.鲍曼不动杆菌对临床常用的13种抗生素均有不同程度的耐药,耐药率35.0%～85.0%.与2008年相比,除左氧氟沙星和妥布霉素耐药率分别下降0.9%和9.0%以外,2009年其余抗生素耐药率均有不同程度地上升,头孢曲松和头孢吡肟耐药率增加了近10.0%,对碳青霉烯类抗生素亚胺培南和美罗培南的耐药率分别达到74.2%(239/602)和70.8%(228/602).鲍曼不动杆菌对替加环素显示了很高的耐药率,耐药率达到78.9%(475/602),而多黏菌素B耐药率仅为3.7%(22/602).PFGE分型显示2008-2009年24株鲍曼不动杆菌有6个克隆型,其中A型最常见,占50%.结论 鲍曼不动杆菌对替加环素的耐药加大了院内感染控制的难度,临床应加强控制,防止多重耐药菌的传播.     

多重耐药鲍曼不动杆菌对替加环素耐药状况分析

目的 了解多重耐药鲍曼不动杆菌对临床常用抗生素及新药替加环素的耐药状况.方法 收集2008-2009年浙江省4所教学医院的602株临床分离鲍曼不动杆菌,采用琼脂稀释法检测其对13种临床常用抗生素的敏感性,以及对多黏菌素B和替加环素的敏感性.同时,采用PFGE技术对24株多重耐药鲍曼不动杆菌进行同源性分析,以确定菌株间的亲缘关系.结果 浙江省4家教学医院2008-2009年分离的鲍曼不动杆菌主要来自于呼吸道标本,2009年达到277株(86.0%),血液标本数量从2008年的15株(5.4%)下降到2009年的5株(1.5%),而其他标本无明显变化.鲍曼不动杆菌对临床常用的13种抗生素均有不同程度的耐药,耐药率35.0%～85.0%.与2008年相比,除左氧氟沙星和妥布霉素耐药率分别下降0.9%和9.0%以外,2009年其余抗生素耐药率均有不同程度地上升,头孢曲松和头孢吡肟耐药率增加了近10.0%,对碳青霉烯类抗生素亚胺培南和美罗培南的耐药率分别达到74.2%(239/602)和70.8%(228/602).鲍曼不动杆菌对替加环素显示了很高的耐药率,耐药率达到78.9%(475/602),而多黏菌素B耐药率仅为3.7%(22/602).PFGE分型显示2008-2009年24株鲍曼不动杆菌有6个克隆型,其中A型最常见,占50%.结论 鲍曼不动杆菌对替加环素的耐药加大了院内感染控制的难度,临床应加强控制,防止多重耐药菌的传播.     

Evaluation of the Etest for penicillin susceptibility testing of Neisseria meningitidis

Susceptibility to penicillin of 30 strains (one isolate per patient) of Neisseria meningitidis isolated from blood (N = 19) or cerebrospinal fluid (N = 11) was studied by two methods. Minimum inhibitory concentrations (MICs) obtained with the Etest were compared to those obtained by the National Committee for Clinical Laboratory Standards agar dilution method. Twenty meningococci (67%) relatively resistant to penicillin were identified by both methods. The mean MIC from the reference method was 0.32 μg/ml (range, 0.2 – 1) and by the Etest method was 0.35 μg/ml (range, 0.19 – 1.25). All MICs obtained by the Etest method were within one dilution of the MICs obtained by the reference method. Because of the increase in penicillin MIC of meningococcal isolates in Spain, we evaluated the performance of the Etest as an alternative method for penicillin-susceptibility testing of N. meningitidis. The Etest is a simple and accurate method for determining the susceptibility of N. meningitidis to penicillin.     

Characterization of Acinetobacter baumannii and meropenem-resistant Pseudomonas aeruginosa in Canada: results of the CANWARD 2007-2009 study

A total of 66 (0.35% of overall isolates) Acinetobacter baumannii and 102 (0.55%) meropenem-resistant Pseudomonas aeruginosa were identified among 18 538 isolates collected from medical centers across Canada during the 2007-2009 period. A. baumannii was most frequently recovered from patients in intensive care units (ICUs; 42.4%) and was isolated mostly from blood cultures (53.0%) and respiratory tract specimens (33.3%). Colistin, meropenem, and amikacin were the most active agents against A. baumannii strains (≥ 92.4% coverage). Gentamicin, levofloxacin, and tigecycline were also active against this bacterial species (MIC(50) 1, 0.12, and 0.5 μg/mL, respectively). Multidrug resistance (MDR; resistance to ≥ 3 antimicrobial classes) was noted in only 4 strains (6.1%), and molecular typing revealed 6 clusters of 2 isolates per cluster that displayed >85% similarity on the dendrogram. Meropenem-resistant P. aeruginosa isolates were primarily obtained from patients in ICUs (40.2%) and the most prevalent specimen types were those collected from the respiratory tract (63.7%), followed by blood cultures (18.6%). Most of the meropenem-resistant P. aeruginosa were resistant to all antimicrobial agents tested, and low susceptibility rates were observed for levofloxacin (8.8%) and gentamicin (28.4%). Amikacin and colistin were active against 67.7% and 88.2% of the isolates, respectively. A total of 68.6% (n = 70) of meropenem-resistant P. aeruginosa were MDR. Pulsed-field gel electrophoresis analysis revealed 94 unique isolates and 2 small clusters (6 and 4 isolates, 1 hospital each). In summary, MDR A. baumannii are rare in Canada and, conversely, meropenem-resistant P. aeruginosa were mostly MDR; however, there was minimal clonal spread among these nonfermentative bacilli.