肺炎链球菌大环内酯类抗生素的耐药性分析

目的本研究通过对肺炎链球菌耐药表型检测分析,掌握本地区肺炎链球菌耐药的现状和趋势。方法本文用E试验和K-B纸片扩散法检测84株肺炎链球菌临床分离株对9种抗生素的敏感性;用双纸片法确定大环内酯类耐药表型。结果84株肺炎链球菌红霉素耐药占85.7%(72/84),对青霉素不敏感率达57.1%(48/84)。左氧氟沙星、阿莫西林/克拉维酸对该组细菌有较好的体外活性,敏感率分别为83.3%(70/84)和88.1%(74/84)。结论肺炎链球菌对大环内酯耐药严重,且表现对四环素、复方磺胺甲噁唑、青霉素等多重耐药;南昌地区大环内酯类耐药表型主要以cMLSB为主。     

肺炎链球菌对大环内酯类抗生素耐药机制研究

目的了解肺炎链球菌对大环内酯类抗生素的耐药机制和转座子整合酶的流行情况。方法188株红霉素耐药肺炎链球菌，用E试验和K—B纸片扩散法检测其对11种抗菌药物的敏感性；用双纸片法（红霉素和克林霉素）确定其耐药表型；用PCR扩增这些菌株的耐药基因ermB、mefa、mefE、tetM及转座子整合酶基因intTn。结果188株红霉素耐药株中耐药基因ermB总检出率为91．5％（172／188），mefE总检出率为38．3％，未检出mefA基因。97．9Yoo的红霉素耐药株中存在转座子整合酶intTn。耐药基因组合ermB（＋）mefE（-）和ermB（＋）mef（＋），占91．5％，两者均呈cMLSB耐药表型。ermB（-）mefE（＋）占8．5％，耐药表型为M型。结论我院分离的肺炎链球菌大环内酯耐药以errnB介导的cMLS。耐药表型为主。转座子可能在本地区肺炎链球菌耐药基因的水平转移和克隆播散中起重要作用。     

肺炎链球菌对大环内酯类抗生素耐药及传播机制研究

目的 研究上海3所医院临床分离肺炎链球菌对大环内酯类抗生素的耐药机制及传播方式。方法收集上海市3所医院临床分离的红霉素耐药肺炎链球菌共118株，用E试验和K-B纸片扩散法检测对12种抗菌药的敏感度；用双纸片法（D试验）确定大环内酯类耐药表型；用PCR扩增检测耐药基因ermB、mefA、mefE、msrD及Tn1545-Tn916家族转座子整合酶基因intTn；用转化试验证实耐药传播方式。结果①118株肺炎链球菌对红霉素的MIC范围为4-256mg／L，其中5．9％对克林霉素敏感，对青霉素不敏感率达72．7％。左氧氟沙星、阿莫西林-克拉维酸对红霉素耐药的肺炎链球菌仍有较好的体外活性；②该组细菌耐药基因ermB检出率为88．1％，mefE、msrD检出率各为50％，未检出，mefA基因，转座子整合酶基因intTn检出率达97．5％。耐药基因组合模式以ermB（＋）reefE（＋）msrD（＋）intTn（＋）和ermB（＋）mefE（-）msrD（-）intTn（＋）为主，两者均为cMLSB型耐药。ermB（-）mefE（＋）msrD（＋）intTn（＋）模式占5．9％，耐药表型为M型。③cMLSB型耐药代表菌株ET37和M型耐药代表菌株RJ324基因组DNA均成功转化敏感株，使之表现红霉素耐药性并可传代。结论上海地区肺炎链球菌对大环内酯抗生素耐药以ermB介导的cMLSB耐药表型为主；大环内酯外排基因有流行趋势，但仅限于起源于肺炎链球菌的，mefE。耐药基因可以转化方式进行传播，转座子可能在本地区肺炎链球菌耐药基因的传播中起重要作用。     

肺炎链球菌大环内酯类抗生素的耐药性分析

目的 本研究通过对肺炎链球菌耐药表型检测分析,掌握本地区肺炎链球菌耐药的现状和趋势.方法 本文用E试验和K-B纸片扩散法检测84株肺炎链球菌临床分离株对9种抗生素的敏感性;用双纸片法确定大环内酯类耐药表型.结果 84株肺炎链球菌红霉素耐药占85.7%(72/84),对青霉素不敏感率达57.1%(48/84).左氧氟沙星、阿莫西林/克拉维酸对该组细菌有较好的体外活性,敏感率分别为83.3%(70/84)和88.1%(74/84).结论 肺炎链球菌对大环内酯耐药严重,且表现对四环素、复方磺胺甲噁唑、青霉素等多重耐药;南昌地区大环内酯类耐药表型主要以cMLSB为主.     

儿童肺炎链球菌血清型分布及其对抗菌药物的耐药性

目的 了解上海交通大学附属儿童医院临床分离的肺炎链球菌血清型分布和对抗菌药物的耐药状况,为控制耐药菌株的播散和疫苗免疫预防的可行性提供参考依据.方法 2007年10月-2008年5月该院就诊患儿咽喉部分泌物中分离的肺炎链球菌株.采用荚膜肿胀试验进行血清型分析,E试验法检测菌株对8种抗菌药物的敏感性.结果 临床共分离到338株肺炎链球菌,主要血清型依次为19F 138株(41.0 %)、19A 67株(19.8%)、14型30株(8.9 %)、23F 14株(4.1 %)、6B 13株(3.8%)、6A 12株(3.6%)和15B 10株(3.0%).在青霉素不敏感菌株(PNSP)和红霉素耐药株(ERSP)中多价疫苗(PCV7)的覆盖率分别为41.9%(26/62)和59.6%(198/332),PCV13的覆盖率分别为72.6%(45/62)和84.9%(282/332).青霉素不敏感肺炎链球菌(PNSP)的血清型主要集中在19F、19A和未能分型株.除未能分型株之外,血清型的分布在2岁以下婴幼儿和2～5岁儿童之间没有显著差异.338株肺炎链球菌中,青霉素敏感株(PSSP)占81.7%(267/338),青霉素中介株(PISP)占10.9%(37/338),青霉素耐药株(PRSP)占7.4%(25/338).19F和19A型的PNSP(PISP+PRSP)对阿莫西林-克拉维酸、头孢曲松的耐药率显著高于PSSP(P<0.01).未能分型株的PNSP对阿莫西林-克拉维酸、头孢曲松以及头孢呋辛的耐药率显著高于PSSP(P<0.01).结论 该院临床分离的肺炎链球菌最常见血清型为19F、19A、14、23F、6B和6A,PCV13能覆盖多数PNSP和ERSP,应用该疫苗应能有效地预防儿童肺炎链球菌的感染和控制耐药菌株传播.     

Distribution of capsular serotypes and macrolide resistance mechanisms among macrolide-resistant Streptococcus pneumoniae isolates in Korea

The mechanism of macrolide resistance was investigated in 251 Streptococcus pneumoniae isolates with reduced susceptibility to erythromycin (erythromycin-resistant S. pneumoniae [ERSP]) collected during the period from 2000 to 2004 in Korea. Among these strains, erm(B) was the most prevalent pneumococcal macrolide resistance genotype. In particular, dual mechanisms of both the erm(B) and mef(A) genes were detected in 77 (30.7%) of 251 ERSP isolates. All of the 77 ERSP isolates, with dual erm(B) and mef(A), showed resistance to 2 or more antimicrobial agents, including penicillin, cefotaxime, clindamycin, tetracycline, and levofloxacin. Serotypes 19F, 23F, 19A, 14, 11A, 6B, 6A, and 9V accounted for 73.3% of ERSP isolates. Most of the strains with serotypes 19F (77.2%) or 19A (87.5%) had the dual erm(B) and mef(A) genes. The prevalence and spread of serotype 19F or 19A isolates may have contributed to the high rate of macrolide-resistant pneumococci in Korea. In addition, we identified the emergence of a macrolide-nonsusceptible nonvaccine serotype 35B, which carries mef(A)-mediated resistance to macrolides. These findings emphasize the need for a continuous monitoring of macrolide-resistant S. pneumoniae in Korea.     

某地区部分医院肺炎链球菌对红霉素的耐药性与基因分析

目的 了解某地区临床分离的肺炎链球菌(SPN)对红霉素的耐药基因流行情况及与耐药表型的关系.方法 采用微量琼脂稀释法,对2008年1月至2009年12月某地区部分医院临床分离到的98株SPN对红霉素的耐药状况进行分析,并用PCR法检测与红霉素耐药基因的关系.结果 98株SPN对红霉素的药敏结果显示,耐药87株,中敏2株,敏感9株;在红霉素耐药菌株中,含有ermB基因70株,含有Mef基因18株,含有ermA基因9株.9株红霉素敏感SPN均未检出ermB基因.结论 ermB基因表达是SPN对红霉素耐药的主要原因,并同时使克林霉素耐药.红霉素已不是治疗SPN的有效药物.     

Macrolide resistance in Streptococcus pyogenes: prevalence,resistance determinants,and emm types

To investigate the antimicrobial resistance trends and the distribution of emm types of group A streptococci (GAS), we examined 1160 clinical isolates of GAS collected between 2003 and 2006. Susceptibilities to commonly used antimicrobial agents were determined by Etest, and macrolide resistance genes were detected by polymerase chain reaction (PCR). GAS isolates were typed by polymerase chain reaction PCR and sequencing of emm gene. The rates of resistance to erythromycin (ERY), clindamycin, azithromycin, tetracycline, and chloramphenicol were 14.9%, 1.4%, 14.9%, 18.9%, 0.6%, respectively. None of the isolates exhibited resistance to penicillin, ceftriaxone, linezolid, moxifloxacin, rifampicin, or vancomycin.     

Mechanisms of macrolide resistance among Streptococcus pneumoniae isolates from Russia

Among 76 macrolide-nonsusceptible Streptococcus pneumoniae isolates collected between 2003 and 2005 from Central Russia, the resistance mechanisms detected in the isolates included erm(B) alone (50%), mef alone [mef(E), mef(I), or a different mef subclass; 19.7%], or both erm(B) and mef(E) (30.3%). Isolates with dual resistance genes [erm(B) and mef(E)] belonged to clonal complex CC81 or CC271.     

Macrolide resistance of Streptococcus pneumoniae isolated during long-term macrolide therapy: difference between erythromycin and clarithromycin

Longterm macrolide therapy (LTMT) has been employed as an effective therapy both for diffuse panbronchiolitis in Japan and for cystic fibrosis in European countries. However, effects on antibiotic susceptibility profiles of microorganisms, associated with such long-term administration of antibiotics, are of concern. We retrospectively identified 57 pneumococcal isolates, recovered from the same number of patients receiving either LTMT with 400mg of clarithromycin daily (CAM group; n = 31) or 600mg of erythromycin daily (EM group; n = 26) by reviewing the patients records at Nara Medical University. On analysis, we found that all isolates recovered from the CAM group and 25 of the 26 recovered from the EM group were resistant to EM, showing either an MLSB or an M phenotype. Interestingly, isolates exhibiting the M phenotype were much less frequent in the CAM group (2 of 31; 6.5%) than in the EM group (15 of 26; 57.7%). No increase in the rate of penicillin resistance was observed in either group. The macrolide resistance profiles of microorganisms may be influenced differently according to differences in the kind of macrolide antibiotics used.     

上海地区肺炎链球菌对氟喹诺酮类的敏感性及其喹诺酮耐药决定区突变研究

目的了解上海地区临床分离肺炎链球菌对氟喹诺酮类等抗菌药物的敏感性，并对氟喹诺酮类敏感菌株的喹诺酮耐药决定区（QRDR）突变进行初步研究。方法收集上海地区部分医院2004-2005年共176株肺炎链球菌临床分离株，用琼脂稀释法测定环丙沙星、左氧氟沙星、加替沙星和莫西沙星等15种抗菌药物的抗菌活性，并选取部分左氧氟沙星敏感肺炎链球菌菌株进行QRDRPCR扩增、测序。结果176株受试菌株中．PSSP、PISP和PRSP各占48．9％、47．1％和4．0％，受试菌株对环丙沙星、左氧氟沙星、加替沙星和莫西沙星敏感率均为100％。QRDR的扩增测序结果发现，20株左氧氟沙星MIC1～2mg／L的敏感菌株中，19株的parC、parE基因上已存在不同程度的氨基酸突变．包括ParC：Phe 105→Leu／Asp136→Tyr，Pare：Asp435→AsnjIle460→ValjAsn477→Lys．而在gyrA、gyrB基因上仅发现点突变，未导致相关氨基酸突变。结论上海地区未发现氟喹诺酮类耐药肺炎链球菌临床分离株，但左氧氟沙星MIC1～2mg／L的敏感株中已发现QRDR一级突变现象，突变的基因位点均见于parC、pare基因。     

126株肺炎链球菌临床菌株的耐药率分析

目的调查呼吸道感染肺炎链球菌对常用抗生素的耐药情况。方法肺炎链球菌用全自动细菌鉴定仪及GPI卡鉴定,药敏试验采用琼脂扩散法。结果126株肺炎链球菌中,青霉素耐药的肺炎链球菌(PRSP)占16.7%,青霉素中度敏感的肺炎链球菌(PISP)占23.0%,肺炎链球菌对红霉素、复方磺胺甲口恶唑、克林霉素的耐药率分别为69.0%、67.5%和65.9%。结论我院呼吸道感染肺炎链球菌对青霉素的耐药率较低,其不敏感性以PISP为主。     

超广谱β-内酰胺酶肺炎克雷伯菌耐药性研究

目的:超广谱β-内酰胺酶(ESBLs)肺炎克雷伯菌的耐药性调查,更好的指导临床用药。方法:应用双纸片协同试验法检测38株产ESBLs的肺炎克雷伯菌的体外抗生素耐药性。结果:ESBLs肺炎克雷伯菌阳性率为10.3％,产ESBLs肺炎克雷伯菌对头孢噻肟、头孢曲松、头孢唑琳、耐药率高达93％,所有受试菌对亚胺培南均敏感。结论:产ESBLs肺炎克雷伯菌引起的感染,治疗应首选亚胺培南、头孢西汀,其次为β-内酰胺酶抑制剂复合制剂。     

Mechanisms of bacterial resistance to macrolide antibiotics

Macrolides have been used in the treatment of infectious diseases since the late 1950s. Since that time, a finding of antagonistic action between erythromycin and spiramycin in clinical isolates¹ led to evidence of the biochemical mechanism and to the current understanding of inducible or constitutive resistance to macrolides mediated by erm genes containing, respectively, the functional regulation mechanism or constitutively mutated regulatory region. These resistant mechanisms to macrolides are recognized in clinically isolated bacteria. (1) A methylase encoded by the erm gene can transform an adenine residue at 2058 (Escherichia coli equivalent) position of 23S rRNA into an ⁶ N, ⁶ N-dimethyladenine. Position 2058 is known to reside either in peptidyltransferase or in the vicinity of the enzyme region of domain V. Dimethylation renders the ribosome resistant to macrolides (MLS). Moreover, another finding adduced as evidence is that a mutation in the domain plays an important role in MLS resistance: one of several mutations (transition and transversion) such as A2058G, A2058C or U, and A2059G, is usually associated with MLS resistance in a few genera of bacteria. (2) M (macrolide antibiotics)- and MS (macrolide and streptogramin type B antibiotics)- or PMS (partial macrolide and streptogramin type B antibiotics)-phenotype resistant bacteria cause decreased accumulation of macrolides, occasionally including streptogramin type B antibiotics. The decreased accumulation, probably via enhanced efflux, is usually inferred from two findings: (i) the extent of the accumulated drug in a resistant cell increases as much as that in a susceptible cell in the presence of an uncoupling agent such as carbonylcyanide-m-chlorophenylhydrazone (CCCP), 2,4-dinitrophenol (DNP), and arsenate; (ii) transporter proteins, in M-type resistants, have mutual similarity to the 12-transmembrane domain present in efflux protein driven by proton-motive force, and in MS- or PMS-type resistants, transporter proteins have mutual homology to one or two ATP-binding segments in efflux protein driven by ATP. (3) Two major macrolide mechanisms based on antibiotic inactivation are dealt with here: degradation due to hydrolysis of the macrolide lactone ring by an esterase encoded by the ere gene; and modification due to macrolide phosphorylation and lincosamide nucleotidylation mediated by the mph and lin genes, respectively. But enzymatic mechanisms that hydrolyze or modify macrolide and lincosamide antibiotics appear to be relatively rare in clinically isolated bacteria at present. (4) Important developments in macrolide antibiotics are briefly featured. On the basis of information obtained from extensive references and studies of resistance mechanisms to macrolide antibiotics, the mode of action of the drugs, as effectors, and a hypothetical explanation of the regulation of the mechanism with regard to induction of macrolide resistance are discussed. Received: February 15, 1999 / Accepted: February 25, 1999     

儿童社区获得性呼吸道感染的肺炎链球菌和流感嗜血杆菌耐药性监测

目的监测2000-2004年连续5年5岁以下呼吸道感染患儿鼻咽拭子分离的肺炎链球菌和流感嗜血杆菌对抗菌药物的耐药性.方法采用E试验和K-B纸片法对临床分离541株肺炎链球菌、521株流感嗜血杆菌进行抗菌药物耐药性测定.结果肺炎链球菌对青霉素不敏感率由2000年的22%增加到2004年的32.9%,P＜0.05;对头孢呋辛和头孢克洛不敏感率由7%增加到25%左右,P＜0.01;对红霉素不敏感率由88%增加到94.3%,P＞0.05;对四环素和复方磺胺甲噁唑不敏感率分别为90%以上和80%以上.流感嗜血杆菌对氨苄西林耐药率和产β内酰胺酶率由2000年的5.0%增加到2004年的14.3%,P＜0.05;对阿莫西林-克拉维酸、头孢曲松和头孢呋辛非常敏感;对头孢克洛不敏感率由2%增加到14.3%,P＜0.01.结论肺炎链球菌对青霉素不敏感率和流感嗜血杆菌对氨苄西林耐药率和产β内酰胺酶率呈明显上升趋势.     

Detection of macrolide resistance in Streptococcus pneumoniae

We determined the susceptibilities of recent clinical isolates of Streptococcus pneumoniae to 19 antibiotics. The frequency of erythromycin nonsusceptibility was high, i.e. 8/13 (61.5%), 10/14 (71.4%) and 11/11 isolates (100%) from 13 penicillin-susceptible, 14 penicillin-intermediate and 11 penicillin-resistant S. pneumoniae, respectively. Macrolide resistance was detected by polymerase chain reaction (PCR) and disk diffusion methods. Of these erythromycin-nonsusceptible pneumococcal isolates, 13/29 (44.8%) isolates contained genomic copies of MEFA and showed non-'D'-shaped zones of inhibition observed around rokitamycin and/or clindamycin disks. Sixteen out of 29 isolates (55.2%) contained copies of ERMB and showed typical 'D'-shaped zones of inhibition, except one isolate. Although the macrolide resistance determinants, MEFA and ERMB, could be identified by PCR and disk diffusion methods, PCR methods were more reliable in elucidating these determinants. The susceptibility pattern to 14-, 15- and 16-membered macrolides and clindamycin differed between the MEFA+ and ERMB+ isolates. All isolates were susceptible to levofloxacin, sparfloxacin and vancomycin. The MICs of sitafloxacin were lowest among the fluoroquinolones examined for 38 isolates.     

儿童患者耐大环内酯类抗生素肺炎链球菌分子流行病学研究

目的分析儿童患者临床分离耐大环内酯类抗生素肺炎链球菌(MRSP)的分子流行病学特征及与国际流行克隆株的相关性。方法采用脉冲场凝胶电泳(PFGE)对107株MRSP行同源性分析。结果107株MRSP共有60个PFGE型,有6种PFGE型≥3株,这6种型共包含53株细菌,占总株数49.5%(53/107)。2003—2004年ermB和mefE阳性菌株中存在与国际流行株密切相关的流行克隆P5型(39.2%,20/51)。结论耐药菌株的克隆传播是2004年我院分离的MRSP流行的重要因素,2003—2004年临床分离株中ermB和mefE同时阳性的菌株经PFGE分型可能与国际流行株有关。     

南京地区肺炎链球菌耐药情况分析

目的了解南京地区肺炎链球菌对常用抗菌药物的耐药性。方法琼脂稀释法测定14种抗菌药物对130株肺炎链球菌MIC。结果130株肺炎链球菌中，耐青霉素肺炎链球菌（PRSP，MIC≥2mg／L）占51．5％；对阿莫西林、头孢呋辛、头孢噻肟和头孢曲松的耐药率依次为6．2％、69．2％、17．7％和3．1％；对红霉素、阿奇霉素、克林霉素和四环素耐药率分别为92．3％、90．8％、89．2％和93．8％；对万古霉素、左氧氟沙星、莫西沙星、替加环素和利奈唑胺均敏感。结论南京地区肺炎链球菌对青霉素、红霉素、阿奇霉素、克林霉素、四环素和头孢呋辛等抗生素耐药性高，应注意合理选择用药。     

某三甲医院儿童肺炎链球菌感染分布及耐药性研究

目的 探讨某三甲医院儿童肺炎链球菌感染分布及耐药性。方法 收集全院2018年8月至2019年7月患儿送检标本,包括痰液、血液、脑脊液、胸水、肺泡灌洗液、脓液、咽拭子等（同一患儿同类标本不重复纳入）,进行病原菌菌株鉴定和药敏试验。结果 1 903例肺炎链球菌中3岁以内患儿1 401株（73.62%）,3～5岁患儿423株（22.20%）,5岁以上患儿71株（3.73%）。5岁以内患儿肺炎链球菌检出率最高,共计1 832株（96.27%）。医院不同病区中,儿科肺炎链球菌感染最多（59.85%）,呼吸科其次（19.02%）。肺炎链球菌标本来源,痰液最多（79.09%）,血液其次（7.62%）。肺炎链球菌冬季检出率最高,秋冬季节明显高于春夏季节（P＜0.05）。肺炎链球菌对红霉素、四环素以及复方新诺明耐药率较高,分别达到96.38%,84.06%,64.74%。未发现对万古霉素、利奈唑胺耐药菌株,对头孢曲松、头孢噻肟、厄他陪南、左氧氟沙星、氧氟沙星、莫西沙星、氯霉素敏感性,敏感性均超过80%。结论 5岁以下患儿易发生肺炎链球菌感染,临床医生应根据药敏结果谨慎、合理选择抗生素,目前仍可将三代头孢作为治疗首选。