肺炎链球菌红霉素相关耐药基因与耐药表型的关系

目的了解肺炎链球菌（SPN）临床分离株红霉素耐药基因的流行状况及和耐药表型的关系。方法对2004年12月-2005年10月,住院患儿分离到的43株肺炎链球菌进行红霉素药敏试验,并用PCR法检测与红霉素耐药相关的红霉素核糖体甲基化酶基因（ermB）、主动外排转运基因（mefA）。结果43株肺炎链球菌红霉素药敏试验40株耐药（93.0%）、3株敏感;红霉素ermB基因总检出率为76.7%,mefA基因总检出率为23.3%,3株红霉素敏感肺炎链球菌均未检出ermB基因和mefA基因;40株耐红霉素肺炎链球菌ermB基因和mefA基因的PCR检出率分别为82.5%和25.0%;共有35株肺炎链球菌检出ermB基因或（和）mefA基因,其中单独携带ermB基因的耐药表型为25株,单独携带mefA基因的耐药表型2株,同时携带ermB基因和mefA基因的耐药表型8株。结论ermB基因和mefA基因同时表达或单独表达均可导致红霉素耐药,ermB基因表达是儿童肺炎链球菌对红霉素耐药的主要原因,mefA基因表达是造成对红霉素耐药的次要原因,红霉素已不是治疗肺炎链球菌的有效药物。     

儿童肺炎链球菌红霉素、四环素相关耐药基因的研究

目的：了解儿童肺炎链球菌（Streptococcus pneumoniae,SP）临床分离株红霉素、四环素耐药基因的流行状况及和耐药表型的关系。方法：对2005年1月-12月从温州附属育英儿童医院住院儿童分离到的47株肺炎链球菌进行了红霉素、四环素药敏试验,并用PCR法检测与红霉素耐药相关的红霉素核糖体甲基化酶基因（ermB）、主动外排转运基因（mefA）,与四环素耐药相关的tetM基因。结果：47株肺炎链球菌红霉素敏感3株、耐药44株;四环素敏感5株、耐药42株。3株红霉素敏感的肺炎链球菌均未检出ermB基因和mefA基因;44株红霉素耐药肺炎链球菌ermB基因和mefA基因的PCR检出率分别为81.8%和29.5%。共有39株肺炎链球菌检出ermB基因或/和mefA基因,其中单独携带ermB基因的耐药表型为29株,占74.4%;单独携带mefA基因的耐药表型2株,占5.1%;同时携带ermB基因和mefA基因的耐药表型8株,占20.5%。47株肺炎链球菌tetM基因的检出率为87.2%,其中四环素耐药组的检出率是95.2%,敏感组为25%。结论：ermB基因和mefA基因同时表达或单独表达均可导致红霉素耐药,ermB基因表达是儿童肺炎链球菌对红霉素耐药的主要原因,mefA基因表达是造成对红霉素耐药的次要原因。tetM基因是造成儿童肺炎链球菌四环素耐药的主要原因。红霉素和四环素已不是治疗肺炎链球菌的有效药物。肺炎链球菌四环素耐药尚存在其他的耐药机制。     

儿科痰培养肺炎链球菌耐药分析

目的 探讨儿科患者下呼吸道感染肺炎链球菌ermB、mefE基因介导的红霉素耐药和克林霉素诱导耐药状况.方法 对1012份儿科送检筛选后的合格痰进行针对性细菌培养,对耐红霉素肺炎链球菌用克林霉素纸片法检测ermB和mefE基因,肺炎链球菌的药敏用ATB STREP.结果 检出肺炎链球菌252株,有33株肺炎链球菌对红霉素耐药,其中ermB基因介导的红霉素耐药菌株21株,占63.6%,mefE基因介导的红霉素耐药菌株12株,占36.4%.结论 对红霉素耐药的肺炎链球菌,其耐药机制以ermB基因介导为主,ermB基因介导的耐药水平高于merE基因介导的耐药水平.     

儿童肺炎链球菌对大环内酯类抗生素的耐药性及相关基因研究

目的:研究介导肺炎链球菌临床分离株耐大环内酯类药物的相关基因。方法:选自儿童感染的32株耐红霉素肺炎链球菌,以PCR检测大环内酯类耐药基因ermB、mefA、mefE。结果:32株肺炎链球菌耐药基因ermB占93.7%,mefE占6.3%,未检出mefA。结论:ermB编码23SrRNA甲基化酶致靶位改变是肺炎链球菌对大环内酯类抗生素耐药的主要机制,大环内酯类抗生素已不是治疗肺炎链球菌的有效药物。     

肺炎链球菌对大环内酯类抗菌药物耐药机制的研究

目的 调查烟台地区肺炎链球菌对抗菌药物的敏感性,研究烟台地区肺炎链球菌对大环内酯类抗菌药物耐药机制.方法 收集社区和临床分离的肺炎链球菌.根据美国临床实验室标准化研究所/美国临床实验室标准化委员会(CLSI/NCCLs)的推荐,用K-B法、Etest法检测肺炎链球菌对青霉素等11种抗菌药物的耐药性及对大环内酯类抗菌药物的耐药表型;用聚合酶链反应(PCR)扩增耐药基因ermB和mefE基因.结果 42株肺炎链球菌中25株对青霉素低度耐药(65.0%),无对青霉素高度耐药株;肺炎链球菌对大环内酯类和克林霉索表现出极高的耐药率,对红霉素和克林霉素耐药率为98.0 %和93.0%;42株肺炎链球菌中40株检测到ermB基因、1株检测剑mefE基因,其中9株菌同时检测到ermB和mefE基因.结论 烟台地区对青霉素不敏感肺炎链球菌检出率高;对红霉素和克林霉素近乎全部耐药,ermB基因介导的靶位改变是烟台地区肺炎链球菌对大环内酯类抗菌药物的主要耐药机制.     

肺炎链球菌Tn1545及Tn917对大环内酯耐药性研究

目的 探讨儿童临床标本中分离的肺炎链球菌耐药特性及ermB基因与转座子Tn1545和Tn917的相互关系.方法 采用E-test法对临床分离的102株肺炎链球菌进行8种抗菌药物的敏感性试验,用PCR扩增检测肺炎链球菌耐药基因ermB和Tn1545、Tn917基因.结果 102株临床分离的肺炎链球菌对红霉素的耐药率为80.3％,中介率为13.7％; ermB基因总检出率为95.1％,84株ermB基因阳性菌株中Tn1545的检出率为86.9％,Tn917的检出率为16.9％;其中,9.5％的ermB基因型菌株检出于Tn1545和Tn917,77.4％的ermB基因型菌株检出Tn1545,7.1％的ermB基因型菌株检出Tn917.结论 肺炎链球菌主要通过ermB基因介导对大环内酯类抗菌药物的耐药性,而ermB基因则主要通过接合转座子Tn1545携带,因此,Tn1545可能在肺炎链球菌耐药基因的播散中起重要作用.     

95株小儿呼吸道感染肺炎链球菌的耐药性研究

目的:分析本院儿科患者下呼吸道感染肺炎链球菌的耐药情况,指导临床合理用药。方法:对本院2007年9月～2009年12月从儿科分离的95株肺炎链球菌用K-B纸片法检测其对青霉素等5种抗生素的敏感度,对耐苯唑西林的菌株用E-test法检测青霉素和头孢曲松的MIC值。结果:95株肺炎链球菌对红霉素、克林霉素高度耐药,耐药率分别为97.9%,96.8%,对左氧氟沙星几乎敏感,未检出耐万古霉素菌株。75株耐苯唑西林菌株用E-test法测试青霉素不敏感率为58.9%(56株),头孢曲松敏感率为98.7%(74株)。ermB基因介导的红霉素耐药菌株92株,占98.9%,mefE基因介导的红霉素耐药仅1株(1.1%)。结论:我院分离的肺炎链球菌耐药严重,PNSP检出率较高(58.9%),对红霉素、克林霉素高度耐药,临床应尽量减少此类药物的经验性用药,依据药敏结果选择抗菌药物进行治疗。     

肺炎链球菌介导大环内酯类及四环素双重耐药性相关元件的研究

目的研究介导肺炎链球菌临床分离株耐大环内酯和四环素药物的基因元件特点。方法 48株耐红霉素肺炎链球菌以PCR检测大环内酯类耐药基因ermB、ermTR、mef与四环素耐药基因tetM及转座子家族Tn916整合酶int,聚合酶链式反应-限制片段长度多态性(RFLP)鉴定mefA和mefE。结果全部菌株均未发现ermTR和mefA基因,48株耐红霉素肺炎链球菌中,仅1株(2.1%)未检出ermB和mefE基因,其余47株均检出ermB和(或)mefE基因,其中ermB 50.0%,ermB+mefE为45.8%及mefE 2.1%;ermB和mefE基因在耐药株中的阳性率分别是95.8%和47.9%;48株肺炎链球菌均检出tetM,int在46株肺炎链球菌中检出占95.8%;45株(93.7%)肺炎链球菌同时存在int、四环素抗性基因和红霉素抗性基因,其中int+tetM+ermB为47.9%,int+tetM+ermB+mefE为45.8%。结论 ermB编码23S rRN(A)甲基化酶致靶位改变是肺炎链球菌对大环内酯药物耐药的主要机制,其次是mefE基因表达主动外排系统导致对大环内酯药物耐药,接合性转座子家族Tn916可能是介导肺炎链球菌对大环内酯类药物、四环素等药物耐药的重要机制之一,并在选择压力下导致耐药菌的广泛传播。     

儿童感染肺炎链球菌耐药性及其耐药基因分型

目的探讨儿童感染肺炎链球菌(streptococcus pneumoniae,SPN)对常用抗菌药物的耐药性及其耐药基因分布。方法选择2013年1月—2015年12月收治的206例感染SPN患儿,进行抗生素药敏试验并应用聚合酶链反应技术检测SPN耐药基因。计数资料比较均采用Z检验,P0.05为差异有统计学意义。结果 SPN对红霉素的耐药率最高,耐药率为95.6%;对四环素和克林霉素的耐药率分别为84.5%、87.4%;所有菌株对万古霉素和利奈唑胺敏感。197株红霉素耐药株中,耐药基因以携带ermB基因84.8%为主,携带mefE基因和mefA基因分别为44.7%、6.1%,其中22.8%携带ermB基因和mefE基因,5.1%携带ermB基因和mefA基因。结论儿童感染的SPN对大环内酯类抗生素耐药率较高;耐药基因以ermB基因介导的靶位改变为最常见,ermB基因、mefE基因和mefA基因三者单独或共同表达均可致SPN红霉素耐药。     

新生儿肺炎链球菌分离株对红霉素耐药性与耐药相关基因研究

目的了解新生儿肺炎链球菌(SPN)临床分离株对红霉素耐药状况和红霉素耐药基因. 方法对2003年12月～2004年5月从常州市妇幼保健院新生儿病房呼吸道感染患者中分离到的20株SPN,用K-B法进行了红霉素药物敏感试验,用PCR检测了与红霉素耐药相关的红霉素核糖体甲基化酶基因(erm)、主动外排转运基因(mefA). 结果 20株SPN红霉素药敏试验17株耐药(85%),3株敏感;erm基因PCR检出20株阳性(100%)、mefA 基因PCR检出17株阳性(85.0%). 结论本地区SPN中因存在红霉素核糖体甲基化酶基因,红霉素主动外排转运体而致红霉素耐药;本研究20株肺炎链球菌erm 或(和)mefA基因阳性率高达100%,红霉素药敏试验与耐药基因检测均提示红霉素已不是治疗新生儿SPN感染的有效药物.     

苏州地区儿童肺炎链球菌临床分离株4种抗生素的耐药基因分子流行病学研究

目的 了解苏州地区儿童肺炎链球菌(SP)青霉素、红霉素、四环素和万古霉素耐药基因的流行状况。方法从2002年9月至2003年4月苏州大学附属儿童医院就诊呼吸道感染患儿痰标本中分离SP；对分离到的31株菌进行4种抗生素药敏试验和pbp2B、PrmA／B、mefA、tetM、vanA、vanB等7种基因的聚合酶链反应(PCR)检测；将pbp2B PCR产物进行测序，并与SPR6株(青霉素敏感株，登录号：NC-003098)pbp2B序列比较。结果31株菌中：(1)青霉素敏感株38．7％(n=12)，不敏感株61．3％(n=19)，pbp2B基因突变株64．5％(n=20)；(2)红霉素敏感株9．7％(n=3)，耐药株80．6％(n=25)，中介株9．7％(n=3)，红霉素不敏感率90．3％，检出PrmA／B基因71％(n=22)，mefA基因32．1％(n=10)，ermA／B和／或mefA基因87．1％(n=27)；(3)四环素敏感株9．7％(n=3)，耐药株80．6％(n：25)，中介株9．7％(n=3)，四环素不敏感率90．3％，检出tetM基因株90．3％(n=28)；(4)万古霉素敏感株100％(n=31)，不敏感率0％，31株菌均未检出vanA、vanB基因。结论苏州地区的SP临床分离株对青霉素、红霉素、四环素具多重高耐药性，对万古霉素具高敏感性之特征。青霉素、红霉素、四环素的耐药相关基因检测提供了该菌耐药的遗传学证据。     

侵入性感染B族链球菌对红霉素及四环素的耐药基因检测

目的了解侵入性感染B族链球菌(GBS)的耐药性及耐药基因谱特点。方法分别采用K-B法、D试验法检测204株GBS对抗菌药物的耐药性和克林霉素诱导型(MLSB)耐药表型,并同时采用聚合酶链反应(PCR)方法检测红霉素及四环素耐药基因ermA、ermB、ermC、ermM、ermTR、mefA、mefE、tetM、tetO、tetK、tetL与红霉素及四环素耐药性的关系。结果红霉素、克林霉素、四环素、氯霉素耐药率分别为44.1%、42.7%、83.7%、18.1%;青霉素、万古霉素未发现耐药菌株;红霉素耐药基因以ermB为主,占71.1%,检出国内未见报道的ermC基因11株及少报道的ermTR基因阳性13株;含≥2种erm基因阳性的GBS占27.8%,有1株GBS不含上述红霉素耐药基因的任何一种基因,但仍对红霉素耐药;四环素耐药基因以tetM和tetO为主,分别为70.5%、56.8%,含≥2种tet基因占72.7%;GBS在围生期以外的感染率不断上升。结论 GBS对红霉素、四环素具有较高的耐药率;ermB是GBS对红霉素耐药的重要基因,在GBS中检出国内未见报道的ermC,GBS对红霉素耐药还存在其他的耐药机制。     

广州地区ST17无乳链球菌的分子流行病学特征及快速鉴定

目的了解广州地区ST17无乳链球菌的分子流行病学特征,运用基质辅助激光解吸/电离飞行时间质谱(Matrix assisted laser desorption/ionization time of flight mass spectrometry,MALDI-TOF MS)建立其快速筛查方法。方法收集侵袭性无乳链球菌98株,进行多位点序列分型(Multilocus sequence typing,MLST)和分子血清学分型,进行药敏试验并检测红霉素和克林霉素耐药基因(ermB、ermA/E、ermTR和linB基因),运用MALDI-TOF MS分析ST17菌株的特征质谱峰。结果所有菌株被分为10个ST,来源于7个克隆群,其中ST17占16.3%。ST17菌株均为血清学Ⅲ型。ST17菌株对红霉素与克林霉素耐药率分别为93.8%和87.5%,检出ermB和mefA/E两种耐药基因,阳性率分别为100.0%和20.0%,未检出ermTR和linB基因。ST17菌株与非ST17菌株对红霉素和克林霉素耐药性以及ermB和mefA/E携带率的差异均具有统计学意义(P<0.05)。10种ST中,仅ST17在7620 Da处有特征质谱峰。结论广州地区流行的侵袭性无乳链球菌具有较高遗传多样性。ST17/血清学Ⅲ型菌株是该地区流行的主要侵袭性菌株之一,对红霉素和克林霉素耐药率高,红霉素耐药主要由ermB介导。MALDI-TOF MS可用于ST17菌株的快速筛查。     

Susceptibility to antimicrobial agents in isolates from invasive Streptococcus pneumoniae in Colombia]

A study was done to determine the patterns of susceptibility to antimicrobial agents in isolates of Streptococcus pneumoniae that caused invasive disease diagnosed in children under the age of 5 in Colombia between 1994 and 1996, as well as to establish the distribution of the capsular types of the resistant isolates. The analysis was done using 324 isolates obtained during the performance of the National Serotyping Protocol for S. pneumoniae carried out in Bogotá, Medellín, and Cali, Colombia, between July 1994 and March 1996. Of the 324 isolates, 119 (36.7%) showed diminished susceptibility to at least one antimicrobial agent, including 39 (12%) that showed diminished susceptibility to penicillin. Of these 39 resistant to penicillin, 29 showed intermediate resistance and 10 showed high resistance. Nine isolates (2.8%) showed resistance to ceftriaxone, 80 (24.7%) to the combination of trimethoprim and sulfamethoxazole (TMS), 49 (15.1%) to chloramphenicol, and 31 (9.6%) to erythromycin. Resistance to two antimicrobial agents was observed in 31 isolates (9.6%); multiple resistance was found in 22 (6.7%). These 22 multiresistant isolates all showed resistance to TMS. The most frequent associations were penicillin, TMS, and erythromycin (5 cases); penicillin, chloramphenicol, TMS, and erythromycin (4 cases); penicillin, ceftriaxone, chloramphenicol, and TMS (3 cases); and penicillin, ceftriaxone, chloramphenicol, TMS, and erythromycin (3 cases). The most frequent serotypes in the penicillin-resistant isolates were: 23F (53.8%), 14 (25.6%), 6B (7.7%), 9V (5.1%), 19F (5.1%), and 34 (2.6%). The most frequent serotypes in the isolates resistant to antimicrobial agents other than penicillin were: 5 (37.5%), 23F (7.5%), 14 (18.8%), and 6B (13.8%). This difference in the distribution of the serotypes was statistically significant (P < 0.0001). The study results indicate the need to maintain active surveillance of antibiotic susceptibility patterns in order to avoid resistance in S. pneumoniae and to provide timely information to change practices regarding prescribing and consuming antimicrobial agents.     

粪肠球菌ermB基因与转座子Tn1545和Tn917关系的探讨

目的研究临床标本中分离的粪肠球菌耐药特性及其ermB基因与转座子Tn1545和Tn917的相互关系。方法采用K-B纸片法对临床分离的86株粪肠球菌进行抗菌药物敏感性试验,用PCR检测粪肠球菌ermB、Tn1545和Tn917基因。结果86株临床分离的粪肠球菌对红霉素的耐药率为74.4%;耐红霉素粪肠球菌中,ermB基因的携带率为95.3%,Tn1545的携带率为81.3%,Tn917的携带率为26.6%;其中,26.2%的ermB基因同时存在于Tn1545和Tn917中,55.4%的ermB基因单纯存在于Tn1545中,1.5%的ermB基因单纯存在于Tn917中。结论粪肠球菌耐大环内酯类抗菌药物的主要耐药基因为ermB基因,ermB基因主要是通过Tn1545来携带其对大环内酯类抗菌药物的耐药性,并且Tnl545可能是引起粪肠球菌多药耐药的重要机制之一。     

一所大型教学医院临床分离肺炎链球菌耐药性分析

目的了解一所大型教学医院临床分离的肺炎链球菌临床分布及耐药情况,为临床合理使用抗菌药物,预防和控制感染提供依据。方法收集中南大学湘雅医院2010年11月-2012年11月临床标本分离的肺炎链球菌192株,均经全自动细菌鉴定仪鉴定。采用K B法检测其对常用14种抗菌药物的敏感性,琼脂稀释法检测青霉素的最低抑菌浓度(MIC)。结果肺炎链球菌主要分离自儿科（36.98%）,标本主要为痰液（64.07%）;患者年龄呈双峰分布,以＜5岁和＞50岁的感染者较多。肺炎链球菌对红霉素、氯霉素、四环素、克林霉素耐药率均＞80%。192株肺炎链球菌青霉素MIC范围为0.015～≥32.0 μg/mL,其中MIC50为2.0 μg/mL,MIC90为16.0 μg/mL。非侵袭性肺炎链球菌耐药性高于侵袭性肺炎链球菌。结论该院肺炎链球菌耐药情况较为严重,在临床上对肺炎链球菌的治疗应重视青霉素耐药菌株的出现。     

Phenotype,genotype, and serotype distribution of macrolide resistant invasive and non-invasive Streptococcus pneumoniae strains,in Sousse,Tunisia

ObjectiveWe determined the macrolide resistance phenotypes and genotypes in Streptococcus pneumoniae isolates in Sousse and assessed the serotype distribution.MethodsWe included S. pneumoniae strains isolated at our laboratory (2010–2013). The antimicrobial susceptibility was tested according to CA-SFM specifications. Serotyping was performed by agglutination of latex particles, to identify a subset of serotypes included in pneumococcal conjugate vaccines. The presence of macrolide resistance genes (ermB, mefA, mel) was detected by PCR.ResultsA total of 52.8% of 140 S. pneumoniae isolates were macrolide-resistant: MLSB (89.2%) and M (10.8%). The MLSB phenotypes were genotypically confirmed by ermB gene presence. 62% had decreased susceptibility to penicillin. The serotypes were: 14, 1, 23F, and 19A. Serotype coverage by PCV7, PCV10 and PCV13 was 44.2%, 73.6%, and 75.6% respectively.Conclusion50% of S. pneumoniae isolates were macrolide resistant. The MLSB phenotype encoded by the ermB gene was the most frequent. Serotype coverage seems inadequate.     

Changes in the nasal carriage of drug-resistant Streptococcus pneumoniae in urban and rural Vietnamese schoolchildren

Studying the antimicrobial drug resistance of nasopharyngeal or nasal carriage isolates of Streptococcus pneumoniae in children is likely to have predictive potential for invasive isolates. Streptococcus pneumoniae nasal carriage was studied in 1422 Vietnamese children. Forty-six percent of 536 isolates showed reduced susceptibility to penicillin and 7% showed intermediate susceptibility to ceftriaxone; and 50% of 518 isolates showed resistance to erythromycin. All isolates were sensitive to levofloxacin and gatifloxacin. Urban and suburban children were significantly more likely to carry drug-resistant isolates than rural children. Rates of non-susceptibility to penicillin and erythromycin increased significantly in the rural province Khanh Hoa in 2003/2004 compared with rates obtained in 1997. An emerging clone of penicillin non-susceptible S. pneumoniae of serogroup 15 was identified, which was widely distributed in addition to the pandemic clones Spain(23F)-1 and Taiwan(19F)-14. Although resistance to fluoroquinolones was not observed, 6 (18%) of 34 isolates had a Lys137Asn mutation in the parC gene. This study shows that drug resistance is increasing in carriage isolates of S. pneumoniae in rural areas in Vietnam owing to spread of pandemic and emerging resistant clones.