鲍曼不动杆菌中16S rRNA甲基化酶基因的分布与耐药性分析

目的分析湖北省肿瘤医院临床分离鲍曼不动杆菌对氨基糖苷类抗生素的耐药性,并研究其16S rRNA甲基化酶基因arm A和rmt B的分布。方法收集该院2009年3月—2010年5月临床分离的鲍曼不动杆菌,采用K-B法进行药敏试验,用PCR法筛选16S rRNA甲基化酶基因arm A、rmt B,并对阳性标本进行测序。结果 56株鲍曼不动杆菌中arm A基因阳性21株(37.5%),未检出rmt B基因菌株。arm A基因阴性菌株对氨基糖苷类抗生素的耐药率显著低于arm A基因阳性菌株。结论近年来该院鲍曼不动杆菌分离率逐年增高。16S rRNA甲基化酶基因arm A在鲍曼不动杆菌广泛存在,且对多种抗生素耐药,应引起临床医师高度关注。     

多重耐药鲍曼不动杆菌16S rRNA甲基化酶、氨基糖苷类修饰酶基因研究

目的了解南京地区多重耐药鲍曼不动杆菌16S rRNA甲基化酶、氨基糖苷类修饰酶基因的存在状况。方法自2007年7—10月间南京地区住院病人标本中分离并筛选出20株多重耐药鲍曼不动杆菌,微量肉汤稀释法测定11种抗菌药物的敏感性;PCR法检测16S rRNA甲基化酶、氨基糖苷类修饰酶基因。结果20株多重耐药鲍曼不动杆菌16S rRNA甲基化酶(armA、rmtB)基因均为阴性;氨基糖苷类修饰酶aac(3)-Ⅰ基因阳性株10株、aac(3)-Ⅱ阳性株1株、aac(6′)-Ⅰb基因阳性株13株、ant(3″)-Ⅰ基因阳性株12株;ant(2″)-Ⅰ基因、aac(6′)-Ⅱ基因及aac(6′)-Ⅰad基因均为阴性。结论南京地区多重耐药鲍曼不动杆菌对氨基糖苷药物耐药的主要原因是aac(3)-Ⅰ、aac(3)-Ⅱ、aac(6′)-Ⅰb、ant(3″)-Ⅰ4种氨基糖苷类修饰酶基因的存在;尚未检出氨基糖苷类修饰酶新亚型———aac(6′)-Ⅰad基因和16S rRNA甲基化酶armA、rmtB基因。     

多重耐药鲍曼不动杆菌16S rRNA甲基化酶基因的研究

目的调查16S rRNA甲基化酶基因在我院院内分离的多重耐药鲍曼不动杆菌中的表达情况,为临床合理使用抗菌药物和控制院内感染的发生提供依据。方法用微量稀释法和纸片扩散法测定菌株的药敏情况。PCR方法检测armA和rmtB16S rRNA甲基化酶基因在46株多重耐药鲍曼不动杆菌中的存在情况。结果 46株多重耐药鲍曼不动杆菌中,40株armA基因阳性,未检出rmtB基因,16S rRNA甲基化酶基因携带率为87%(40/46)。结论我院院内分离的多重耐药鲍曼不动杆菌16S rRNA甲基化酶基因携带率很高,可能与氨基糖苷类耐药有关。     

革兰阴性杆菌16S rRNA甲基化酶基因检测及作用研究

目的分析上海中医药大学附属普陀医院临床分离的革兰阴性杆菌中16S rRNA甲基化酶基因的流行情况及革兰阴性杆菌的氨基糖苷类耐药机制。方法收集临床分离的对阿米卡星和/或庆大霉素耐药的革兰阴性杆菌53株。采用聚合酶链反应（PCR）法检测16S rRNA甲基化酶基因：armA、rmtA、rmtB、rmtC、rmtD、npmA;PCR阳性产物测序分析。构建PET32-armA和PET32-rmtB的重组质粒并转化入宿主菌BL21中。纸片扩散法（K-B）检测临床分离16S rRNA甲基化酶基因阳性菌株和重组菌对5种氨基糖苷类药物的敏感性。结果 53株耐药菌中5株鲍曼不动杆菌、2株肺炎克雷伯和1株阴沟肠杆菌检出armA基因,2株大肠埃希菌检出rmtB基因。获得PET32-armA和PET32-rmtB的重组BL21菌株。PET32-armA和PET32-rmtB的重组菌均获得氨基糖苷类抗菌药物耐药性。结论本院临床样本检测到16S rRNA甲基化酶基因armA和rmtB阳性菌株,armA基因存在于鲍曼不动杆菌、肺炎克雷伯菌和阴沟肠杆菌中;rmtB基因位于大肠埃希菌中。将armA和rmtB基因转入非耐药的宿主菌中可以诱导其对氨基糖苷类抗菌药物的耐药。     

多重耐药鲍曼不动杆菌16S rRNA甲基化酶基因及qacE△1-sul1基因检测的研究

目的 了解新疆地区鲍曼不动杆菌（ABA）16S rRNA甲基化酶基因及qacE△1-sul1基因存在状况。 方法 对临床分离的40株ABA用PCR法检测16S rRNA甲基化酶基因及qacE△1-sul1耐药基因并与基因库比对。 结果 40株MDR-ABA 6种16S rRNA甲基化酶基因检出结果与美国GenBank登录的相同;40株ABA菌中qacE△1-sul1耐药基因阳性21株（52.5%）。 结论 本组40株ABA未检出16S rRNA基因甲基化酶基因,qacE△1-sul1基因检测结果提示这些菌株52.5%携带Ⅰ类整合子,是本组细菌多重耐药表型的原因之一。     

多重耐药鲍曼不动杆菌氨基糖苷类耐药基因的研究

目的调查山东省潍坊市人民医院临床分离的多重耐药鲍曼不动杆菌氨基糖苷类耐药基因的流行情况,为院内感染控制提供依据。方法采用VITEK2全自动微生物仪对2013年11月26日至12月12日山东省潍坊市人民医院临床分离的9株多重耐药鲍曼不动杆菌进行细菌鉴定和药敏试验,部分抗菌药物的敏感度检测采用纸片扩散法。聚合酶链反应检测氨基糖苷类耐药基因,对部分阳性基因进行测序。结果 9株多重耐药鲍曼不动杆菌中,2株aac(3)-Ⅰ基因阳性,3株ant(3″)-Ⅰ基因阳性,3株aac(6′)-Ⅰ基因阳性,9株armA基因阳性。所有菌株对氨基糖苷类抗菌药物阿米卡星、庆大霉素和妥布霉素耐药。5株标本来源于重症监护病房,3株标本来源于神经外科病房。所有标本来源于痰液。结论该院这段时间分离的多重耐药鲍曼不动杆菌对阿米卡星、庆大霉素和妥布霉素同时耐药与携带armA氨基糖苷类耐药基因有关。院感部门应重点监测重症监护病房和神经外科病房多重耐药鲍曼不动杆菌引起的院内感染。     

耐氨基糖苷类抗生素鲍曼不动杆菌中armA和rmtB甲基化酶基因的检测

目的了解我院临床分离鲍曼不动杆菌对氨基糖苷类抗生素的耐药性,并检测其耐药基因。方法收集我院2009年1—10月临床分离鲍曼不动杆菌共80株,采用CLSI推荐的纸片扩散法（K-B法）对分离菌株进行抗生素敏感试验。用PCR法筛选2种甲基化酶基因armA、rmtB,并对阳性标本进行测序。结果 80株鲍曼不动杆菌对阿米卡星、庆大霉素、链霉素和奈替米星的耐药率分别为66.2%、72.5%、87.5%和68.8%,对4种氨基糖苷类抗生素全部耐药52株（65%）,耐药菌株中armA基因阳性48株（60%）,未检出rmtB阳性菌株。结论近年来我院鲍曼不动杆菌分离率逐年增高,16S rRNA甲基化酶基因armA在鲍曼不动杆菌广泛存在,且对多种抗生素耐药,应引起临床医师高度关注。     

36株多重耐药鲍曼不动杆菌对氨基糖苷类药物耐药基因的流行病学研究

目的了解多重耐药鲍曼不动杆菌中氨基糖苷类耐药基因的存在情况。方法收集2012年8—11月江苏大学附属医院和镇江市第一人民医院住院患者的临床标本中分离到的多重耐药鲍曼不动杆菌菌株36株。应用KB纸片扩散法检测多重耐药鲍曼不动杆菌对抗菌药物的敏感性、应用PCR检测细菌对氨基糖苷类药物的耐药基因。结果36株多重耐药鲍曼不动杆菌对头孢哌酮一舒巴坦有较高的敏感率（33．3％）,对其他抗菌药物的敏感率均较低（20．0％）。36株多重耐药鲍曼不动杆菌中氨基糖苷类耐药基因aac（3）-I、aac（6’）Ib、aph（3’）-I和16SrRNA甲基化酶基因armA的阳性率分别为72．2％（26株）、72．2％（26株）、80．6％（29株）和80．6％（29株）。结论本组多重耐药鲍曼不动杆菌多耐药情况比较严重,其对氨基糖苷类药物耐药与氨基糖苷类耐药基因的存在密切相关。     

革兰阴性杆菌16S rRNA甲基化酶耐药研究进展

氨基糖苷类抗生素通过作用于细菌核糖体30S亚基的16S rRNA高度保守的A位点,干扰细菌蛋白质的合成,从而引起细菌死亡。氨基糖苷类抗生素具有杀菌作用,抗菌谱广,较长抗生素后效应等特点,而且还与其他抗菌药物有协同作     

鲍曼不动杆菌耐药性及氨基糖苷类耐药基因检测及分析

目的 探讨医院内鲍曼不动杆菌分离菌株氨基糖苷类耐药基因存在情况以及药物敏感性,指导临床合理应用抗生素.方法 采用法国梅里埃VITEK2 COMPACT全自动微生物分析仪对临床标本进行细菌鉴定和药物敏感试验.聚合酶链反应（PCR）检测aac（3）-Ⅰ,aac（3）-Ⅱ,aac（6′）-Ⅰ,aac（6′）-Ⅱ四种氨基糖苷类修饰酶耐药基因.结果 共分离鉴定出36株鲍曼不动杆菌,药敏结果显示分离菌株呈现多重耐药,耐药性最低为多粘菌素,未检测到耐药菌株;其次为亚胺培南,耐药率为55%;其余抗生素耐药率均在86%以上.耐药基因检测显示aac（3）-Ⅰ阳性11株,占30.6 %,aac（3）-Ⅱ阳性 12 株,占33.3 %,aac（6′）-Ⅰ阳性15株,占41.7 %,aac（6′）-Ⅱ未检测出.常见的基因组合为aac（3）-Ⅰ与aac（6′）-Ⅰ同时阳性,占36.4%.结论 鲍曼不动杆菌临床分离株耐药现象严重,aac（3）-Ⅰ,aac（3）-Ⅱ与aac（6′）-Ⅰ耐药基因携带率较高.     

Dissemination of 16S rRNA methylase-mediated highly amikacin-resistant isolates of Klebsiella pneumoniae and Acinetobacter baumannii in Korea

Novel 16S rRNA methylase-mediated high-level resistance to amikacin and arbekacin has been reported recently in clinical isolates of Gram-negative bacilli only from several countries. We tested amikacin- or arbekacin-nonsusceptible Gram-negative bacilli isolated in 2003 and 2005 at a tertiary-care hospital in Korea by polymerase chain reaction to detect 16S rRNA methylase genes. armA alleles were detected in 14 isolates of Klebsiella pneumoniae, 10 other species of Enterobacteriaceae, and 16 Acinetobacter baumannii, whereas the rmtB allele was detected in 1 K. pneumoniae isolate. The resistance 1st detected in 2003 persisted in 2005. 16S rRNA methylase-producing isolates were highly resistant to arbekacin and amikacin, and were mostly coresistant to levofloxacin. Most K. pneumoniae isolates also produced extended-spectrum beta-lactamases and plasmid-mediated AmpC beta-lactamases, and most A. baumannii isolates were nonsusceptible to carbapenems.     

Identification of 16S rRNA methylase-producing Acinetobacter baumannii clinical strains in North America

Five highly amikacin-resistant Acinetobacter baumannii isolates were collected at a medical center in Pennsylvania. The aminoglycoside resistance was due to the production of the 16S rRNA methylase ArmA. Two of the isolates coproduced OXA-23 beta-lactamase and were highly resistant to carbapenems as well. The isolates were genetically closely related by pulsed-field gel electrophoresis.     

16SrRNA甲基化酶基因在产ESBLs肠杆菌科细菌中的分布

目的了解临床分离的产超广谱β-内酰胺酶（ESBLs）的革兰阴性肠杆菌科细菌中16SrRNA甲基化酶基因的分布情况。方法对临床分离的70株革兰阴性肠杆菌科细菌用VITEK．32型全自动微生物分析系统进行细菌鉴定,用纸片扩散法检测ESBLs,并用聚合酶链反应（PCR）检测armA、rmtA、rmtB、rmtC、rmtD和npmA6种16SrRNA甲基化酶基因,对检测的阳性产物进行测序,并通过GenBank比对DNA序列。结果70株产ESBLs革兰阴性肠杆菌中,9株16SrRNA甲基化酶基因阳性,其中5株检出armA基因,4株检出rmtB基因,2株同时检出armA和rmtB基因,rmtA、rmtC、rmtD、npmA4种基因扩增均为阴性。结论不同地区医院16SrRNA甲基化酶基因的分布情况各不相同。     

多重耐药不动杆菌16S rRNA甲基化酶和同源性研究

Objective To characterize 16S rRNA methylase encoding genes associated with aminoglycoaides resistance, gene cassettes of class Ⅰ integrons of the multidrug-resistant Acinetobctcter spp. The sixty one Acinetobacter isolates were collected at the Second Hospital of Shanxi Medical Uni versity from July, 2007 to May, 2008. Methods Species identification was confirmed by sequence analysis of the blaOXA-51-like gene and 16S-23S rRNA gene space-region. Antimierobial susceptibility tests were performed by agar dilution method. 16S rRNA methylaae encoding genes and gene cassettes associated with integrons were amplified by PCR method. Results Among the sixty one strains, there were fifty five of Acinetobacter baumannii, three genospecies 3TU, one 13TU, one Aeinetobaeter ealcoacetieus, and one Aeinetobaeter haemolytieus. Forty eight isolates showed high-level resistance to three aminoglyeosides, including amikaein, tobramyein and gentamicin. The armA gene was found in 47 isolates and all isolates were negative for rmtA, rmtB, rmtC and rmtD genes. The Intl gene was found in 27 isolates. The gene cassettes contained arr-3, accA4,ctacCI ,catB8, aadA1 or dfrA12 genes. According to the PFGE DNA patterns, 5 distinct clones of armA-pasitive strains were identified. Clone A and Clone B were the dominant clones, widely distributed among different divisions. Condnsions 16S rRNA methylase encoding gene (armA) distributed widely in muhidrug-resistant Acinetobacter spp. The armA gene is not located in class Ⅰintegron. The class Ⅰ integron carries multiple resistant genes associated with aminoglycosides and chloramphenieol resistance.PFGE analysis suggests that armA-pesitive strains are widely spread in our hospitaL Effective infection control measure should be conducted in order to control the outbreak of resistant bacteria.     

多重耐药不动杆菌16S rRNA甲基化酶和同源性研究

Objective To characterize 16S rRNA methylase encoding genes associated with aminoglycoaides resistance, gene cassettes of class Ⅰ integrons of the multidrug-resistant Acinetobctcter spp. The sixty one Acinetobacter isolates were collected at the Second Hospital of Shanxi Medical Uni versity from July, 2007 to May, 2008. Methods Species identification was confirmed by sequence analysis of the blaOXA-51-like gene and 16S-23S rRNA gene space-region. Antimierobial susceptibility tests were performed by agar dilution method. 16S rRNA methylaae encoding genes and gene cassettes associated with integrons were amplified by PCR method. Results Among the sixty one strains, there were fifty five of Acinetobacter baumannii, three genospecies 3TU, one 13TU, one Aeinetobaeter ealcoacetieus, and one Aeinetobaeter haemolytieus. Forty eight isolates showed high-level resistance to three aminoglyeosides, including amikaein, tobramyein and gentamicin. The armA gene was found in 47 isolates and all isolates were negative for rmtA, rmtB, rmtC and rmtD genes. The Intl gene was found in 27 isolates. The gene cassettes contained arr-3, accA4,ctacCI ,catB8, aadA1 or dfrA12 genes. According to the PFGE DNA patterns, 5 distinct clones of armA-pasitive strains were identified. Clone A and Clone B were the dominant clones, widely distributed among different divisions. Condnsions 16S rRNA methylase encoding gene (armA) distributed widely in muhidrug-resistant Acinetobacter spp. The armA gene is not located in class Ⅰintegron. The class Ⅰ integron carries multiple resistant genes associated with aminoglycosides and chloramphenieol resistance.PFGE analysis suggests that armA-pesitive strains are widely spread in our hospitaL Effective infection control measure should be conducted in order to control the outbreak of resistant bacteria.     

多重耐药不动杆菌16S rRNA甲基化酶和同源性研究

目的 调查2007年7月-2008年5月山西医科大学第二附属医院临床分离的61株多重耐药不动杆菌中介导氨基糖苷类抗生素高水平耐药的16S rRNA甲基化酶基因和Ⅰ类整合子携带耐药基因的分布.方法 利用blaOXA-51基因及16S rRNA-23S rRNA序列进行菌株鉴定,琼脂稀释法测定12种抗菌药物对61株不动杆菌的MIC,PCR筛选6种16S rRNA甲基化酶基因以及整合子基因盒,脉冲场凝胶电泳(PFGE)分析菌株同源性.结果 61株临床分离不动杆菌中55株为鲍曼不动杆菌、3株为3TU不动杆菌、l株13TU不动杆菌、1株醋酸钙不动杆菌、l株溶血不动杆菌.48株不动杆菌对阿米卡星、庆大霉素、妥布霉素均耐药,其中有47株检出armA基因;未检出rmtA、rmtB、rmtC、mad和npmA基因.armA基因阳性的菌株中Ⅰ类整合子阳性27株,分别携带arr-3、accA4、aacCl、catB8、aadA1和dfrA12基因.PFGE条带分析发现47株armA阳性菌株分为5个克隆,其中A、B为主要克隆,分布在我院多个科室中.结论 16S rRNA甲基化酶基因armA在多重耐药不动杆菌中广泛存在,armA基因不位于Ⅰ类整合子中,不动杆菌Ⅰ类整合子携带耐药基因主要介导对氨基糖苷类及氯霉素的耐药性.PFGE结果显示armA基因阳性菌株在我院呈克隆播散,必须采取有效的措施来控制耐药菌的传播.     

多重耐药不动杆菌16S rRNA甲基化酶和同源性研究

Objective To characterize 16S rRNA methylase encoding genes associated with aminoglycoaides resistance, gene cassettes of class Ⅰ integrons of the multidrug-resistant Acinetobctcter spp. The sixty one Acinetobacter isolates were collected at the Second Hospital of Shanxi Medical Uni versity from July, 2007 to May, 2008. Methods Species identification was confirmed by sequence analysis of the blaOXA-51-like gene and 16S-23S rRNA gene space-region. Antimierobial susceptibility tests were performed by agar dilution method. 16S rRNA methylaae encoding genes and gene cassettes associated with integrons were amplified by PCR method. Results Among the sixty one strains, there were fifty five of Acinetobacter baumannii, three genospecies 3TU, one 13TU, one Aeinetobaeter ealcoacetieus, and one Aeinetobaeter haemolytieus. Forty eight isolates showed high-level resistance to three aminoglyeosides, including amikaein, tobramyein and gentamicin. The armA gene was found in 47 isolates and all isolates were negative for rmtA, rmtB, rmtC and rmtD genes. The Intl gene was found in 27 isolates. The gene cassettes contained arr-3, accA4,ctacCI ,catB8, aadA1 or dfrA12 genes. According to the PFGE DNA patterns, 5 distinct clones of armA-pasitive strains were identified. Clone A and Clone B were the dominant clones, widely distributed among different divisions. Condnsions 16S rRNA methylase encoding gene (armA) distributed widely in muhidrug-resistant Acinetobacter spp. The armA gene is not located in class Ⅰintegron. The class Ⅰ integron carries multiple resistant genes associated with aminoglycosides and chloramphenieol resistance.PFGE analysis suggests that armA-pesitive strains are widely spread in our hospitaL Effective infection control measure should be conducted in order to control the outbreak of resistant bacteria.