血流感染肺炎克雷伯菌中CRISPR-Cas系统的分布及其与毒力基因和耐药的关系

的 了解血流感染肺炎克雷伯菌中CRISPR-Cas系统的分布特征并分析其与毒力基因和耐药的关系。方法 收集非重复血流感染肺炎克雷伯菌248株，使用Vitek2-Compact全自动微生物分析系统进行菌株鉴定及药物敏感性分析，PCR检测CRISPR-Cas系统3个相关基因(CRISPR1、CRISPR2和cas1)、筛查6种常见高毒力荚膜血清型(K1、K2、K5、 K20、K54和K57)、12种毒力基因及检测13种耐药基因，用χ2检验比较携带有CRISPR-Cas系统菌株与不携带CRISPR-Cas系统菌株毒力及耐药差异。结果 CRISPR-Cas系统的检出率为29.8%(74/248)；K1型是携带CRISPR-Cas系统肺炎克雷伯菌的主要荚膜血清型，占 28.4%(21/74)；除kpn基因外，携带CRISPR-Cas系统菌株的毒力基因检出率均大于不携带CRISPR-Cas系统菌株，其中7种差异有统计学意义；除对氨苄西林耐药率达100%外，携带有CRISPR-Cas系统菌株的其他抗菌药物耐药率均小于不携带有CRISPR-Cas系统菌株，其中13种差异有统计学意义；携带CRISPR-Cas系统菌株的耐药基因阳性率小于不携带CRISPR-Cas系统的菌株，且blaKPC、blaSHV、qnrS基因差异有统计学意义。结论 高毒力荚膜血清型肺炎克雷伯菌中主要为K1型携带CRISPR-Cas系统，携带CRISPR-Cas系统的肺炎克雷伯菌相对于不携带CRISPR-Cas系统菌株的毒力基因阳性率高，耐药率低，耐药基因的阳性率低。CRISPR-Cas系统可能能降低耐药基因在肺炎克雷伯菌中的水平传播，尤其是在K1型肺炎克雷伯菌。     

某三甲医院肺炎克雷伯菌毒力基因分布、耐药性及患者临床特征分析

目的 分析某三级甲等医院临床分离的肺炎克雷伯菌毒力基因分布、耐药性及患者临床特征,为临床诊治提供依据。方法 收集临床分离的107株肺炎克雷伯菌进行毒力基因检测和药敏试验,并收集患者的临床资料,采用iucA基因和peg-344基因阳性区分高毒力肺炎克雷伯菌(hvKP)和经典肺炎克雷伯菌(cKP),比较分析hvKP和cKP的毒力基因携带率、药敏结果以及患者临床特征。结果 107株肺炎克雷伯菌中共检出hvKP 57株,占比53.3%,hvKP组的毒力基因iucA、iroB、rmpA、rmpA2、peg-344基因携带率明显高于cKP组,与cKP相比,hvKP对头孢唑林、头孢呋辛、环丙沙星、复方磺胺甲恶唑耐药率较低;hvKP及cKP主要分离自痰标本,与hvKP相比,年龄大于75岁的患者更易引起cKP感染。结论 本院hvKP临床分离率较高,但老年人更易引起cKP感染。与cKP相比,hvKP对临床常用抗菌药物耐药率较低,临床医生应根据菌株特性和患者临床特征,制定合理的诊治方案。     

某三甲医院肺炎克雷伯菌毒力基因分布、耐药性及患者临床特征分析

目的 分析某三级甲等医院临床分离的肺炎克雷伯菌毒力基因分布、耐药性及患者临床特征,为临床诊治提供依据。方法 收集临床分离的107株肺炎克雷伯菌进行毒力基因检测和药敏试验,并收集患者的临床资料,采用iucA基因和peg-344基因阳性区分高毒力肺炎克雷伯菌(hvKP)和经典肺炎克雷伯菌(cKP),比较分析hvKP和cKP的毒力基因携带率、药敏结果以及患者临床特征。结果 107株肺炎克雷伯菌中共检出hvKP 57株,占比53.3%,hvKP组的毒力基因iucA、iroB、rmpA、rmpA2、peg-344基因携带率明显高于cKP组,与cKP相比,hvKP对头孢唑林、头孢呋辛、环丙沙星、复方磺胺甲恶唑耐药率较低;hvKP及cKP主要分离自痰标本,与hvKP相比,年龄大于75岁的患者更易引起cKP感染。结论 本院hvKP临床分离率较高,但老年人更易引起cKP感染。与cKP相比,hvKP对临床常用抗菌药物耐药率较低,临床医生应根据菌株特性和患者临床特征,制定合理的诊治方案。     

引起非妊娠成年患者血流感染的无乳链球菌毒力基因及分子分型研究

目的 对上海交通大学医学院附属新华医院引起非妊娠成人患者血流感染的无乳链球菌进行毒力基因检测和 分子分型研究。方法 收集上海市某三甲医院2012—2020年分离的引起非妊娠成人患者血流感染的无乳链球菌(group B Streptococcus,GBS)临床菌株,通过病例系统收集相应患者的临床资料进行统计分析。采用MALDI-TOF MS对菌株进行鉴 定;采用Vitek-2 Compact联合纸片扩散法(K-B法)进行药物敏感试验;采用PCR方法和琼脂糖凝胶电泳方法进行与菌株黏附、 侵袭和免疫逃逸相关的毒力基因检测;采用多重PCR方法进行血清学分型;采用MLST方法进行分子分型研究,分型结果采用 Bionumeric 8.0软件分析菌株间亲缘关系。结果 2012—2020年共分离到13株符合入组条件的GBS菌株,相应患者人群以中老 年为主,占92.4%;男女比例为3.3:1,且大部分患者有心律失常、糖尿病或肝硬化等基础疾病。药敏结果提示菌株对氨苄西 林、万古霉素、利奈唑胺、青霉素、头孢曲松、替加环素等抗菌药物仍然保持高度敏感,对克林霉素耐药率最高达84.6%,其 次是四环素(61.5%)和红霉素(53.8%)。黏附作用相关基因中fbsB、pavA基因携带率100%,而菌毛编码基因gbsPC1的携带率最低 (46.15%);侵袭力相关基因中cylX、cylD、cylG、acpC、cylZ、cylA、cylB、cylE、cylF、cylI、cylJ、cfb、hylB和bca基因的携 带率100%,cylK和spb1的携带率较低分别为7.69%和38.45%,rib基因在13株菌种均未检出。免疫逃避相关基因中cpsF、cpsE、 cpsD、cpsB、neuA、neuD、neuC、neuB和pbp1A的基因携带率为100%,bac、cpsJ、cpsI、cpsG的携带率较低。菌株的血清学分 型以Ⅰb型为主,占38.5%(5/13);13株菌共分为10种ST型,同源性分析显示菌株亲缘关系较远。结论 无乳链球菌引起非妊娠 成人患者血流感染的危险因素可能为高龄、男性以及心律失常等基础疾病,菌株对克林霉素、四环素耐药率较高,且携带较多 毒力基因,血清分型以Ⅰb型为主,但ST分型较为分散,未出现暴发流行趋势。     

苯唑西林和万古霉素对金葡菌儿童株和成人株的体外抗菌活性差异

目的 分析苯唑西林和万古霉素对金葡菌儿童株和成人株的体外抗菌活性差异。方法用纸片扩散法检测苯唑西林和万古霉素对金葡菌的抑菌圈直径，用E-test法检测最低抑菌浓度（MIC），比较两种抗生素对金葡菌儿童株和成人株的抗菌活性。结果 纸片扩散法和E-test法检测金葡菌的药敏结果基本一致，E—test法结果显示儿童临床分离株对苯唑西林的敏感、中介和耐药率分别为88．2％、3．2％和8．6％，MIC50和MIC90分别为0．75和3．0μg／ml，成人临床分离株的敏感、中介和耐药率分别为28．2％、2．6％和69．2％。MIC50和MIC60均〉256ug／ml，成人株对苯唑西林的耐药率显著高于儿童株（r=107．1，P〈0．001）。所有菌株均对万古霉素敏感，其中儿童临床分离株的MIC50和MIC60分别为1．5和2．0μg／ml，成人临床分离株的MIC50和MIC60均为4．0μg／ml。结论 金葡菌成人株对万古霉索和苯唑西林的耐药性高于儿童株，临床应根据药敏试验结果合理选择抗生素，避免抗生素滥用。     

化脓性链球菌耐药与毒力基因研究

目的 调查一组70株化脓性链球菌耐药与毒力基因存在状况，以及菌株间的亲缘关系。方法 70株化脓性链球菌分离自日照市中心医院2012-2017年急性扁桃体炎、急性咽炎患者的咽拭子标本。5种抗菌药物敏感性试验为Kirby-Bauer法。采用聚合酶链反应(PCR)及序列分析的方法分析8种耐药基因和3种毒力基因。检测结果作样本聚类分析(UPGMA法)。结果 70株化脓性链球菌对青霉素、苯唑西林、万古霉素敏感性均达100.00%，对红霉素耐药率较高(94.29%)。青霉素耐药基因均为阴性，大环内酯类耐药基因检出ermB和mefA基因，其中ermB和/或mefA阳性66株(94.29%)。可移动遗传元件标志基因intTN916检出率高(94.29%)。3种毒力基因均有较高的检出率：spyA58株(82.86%)、sagA68株(97.14%)、slo64株(91.43%)。样本聚类分析可见，70株化脓性链球菌分为A~N共14个分类单元，根据是否携带ermB基因，可分为Ⅰ、Ⅱ二个群，Ⅰ群9个分类单元均携带ermB基因，Ⅱ群5个分类单元均不携带ermB基因。结论 70株化脓性链球菌携带的大环内酯类耐药基因ermB和mefA，以及可移动遗传元件标志基因intTN916是对红霉素产生耐药的重要原因。spyA、sagA、slo等3种毒力基因是化脓性链球菌常见的毒力基因,推测它们是化脓性链球菌感染导致感染灶局部炎症和坏死的原因。     

贵阳地区儿童幽门螺杆菌临床分离菌株毒力基因cagA和vacA的表达情况以及与抗生素耐药之间的关系

目的分析贵阳地区儿童幽门螺杆菌临床分离菌株的毒力基因cagA和vacA的表达情况 ,以及探讨其和幽门螺杆菌耐药之间的关系.方法从有上消化道症状的患儿的的胃窦粘膜中分离培养出幽门螺杆菌31株 ,采用聚合酶链式反应检测cagA和vacA的分布情况.用琼脂稀释法检测幽门螺杆菌对阿莫西林、克拉霉素、甲硝唑和左氧氟沙星的耐药性.结果本地区儿童幽门螺杆菌的cagA基因的阳性率为83 .87% .vacA基因亚型s1a、s1b、s1c、m1和m2的检出率分别为83 .87% (26/31)、0% (0/31)、19 .35% (6/31)、12 .90% (4/31)和74 .19% (23/31).优势基因为vacAs1am2型.毒力基因与不同的疾病之间无相关性.cagA基因和vacA基因与阿莫西林、克拉霉素、甲硝唑及左氧氟沙星耐药无相关性(P>0 .05).结论贵阳地区儿童的毒力基因cagA+和vacAs1m2型为主.毒力基因与抗生素的耐药性之间无相关性.     

血流感染肺炎克雷伯菌pLVPK毒力质粒的分布及与耐药的关系

目的 了解血流感染肺炎克雷伯菌中pLVPK毒力质粒的分布情况，分析其与荚膜血清分型及耐药之间的关系。方法 收集医院2016年1月-2017年6月所有非重复血流感染的肺炎克雷伯菌96株，使用Vitek-Compact全自动微生物分析系统进行菌株鉴定及药物敏感性分析；PCR方法检测6种常见高毒力荚膜血清型、7种常见毒力基因、13种常见耐药基因及毒力质粒pLVPK相关基因，使用χ2检验进行统计学分析。结果 血流感染肺炎克雷伯菌株中携带pLVPK毒力质粒率39.6%。其中毒力质粒pLVPK阳性菌株K1荚膜血清分型率显著高毒力质粒pLVPK阴性菌株(P<0.05)，而在其他非高毒力荚膜血清分型上，毒力质粒pLVPK阳性菌株显著低于毒力质粒pLVPK阴性菌株(P<0.05)。pLVPK毒力质粒阳性菌株的毒力基因携带率均显著高于pLVPK毒力质粒阴性菌株(P<0.05)。而pLVPK毒力质粒阳性菌株在耐药性则显著低于pLVPK毒力质粒阴性菌株(P<0.05)，其中pLVPK毒力质粒阳性菌株对blaKPC、blaTEM、blaCTX-M、qnrB及acc(6')-Ib-cr基因的携带显著低于pLVPK毒力质粒阴性菌株(P<0.05)。结论 pLVPK毒力质粒主要集中在K1荚膜血清分型血流感染肺炎克雷伯菌株，pLVPK毒力质粒与毒力基因的携带成正相关，而pLVPK毒力质粒也直接影响了血流感染菌株的耐药性及耐药基因的携带。     

儿童与成人感染的病原菌谱及耐药性分析

目的：比较儿童与成人常见病原菌耐药状况,为临床合理选用抗菌药物提供依据。方法：监测2012年福建省泉州市儿童医院与福建医科大学附属泉州第一医院临床分离细菌耐药状况,以Whonet 5.5软件进行数据分析,比较儿童与成人临床常见病原菌的耐药性差异。结果：从儿童中分离得到致病菌2324株,其中G＋菌945株,占40.66%,G-菌1379株,占59.34%;数量居前6位的分离细菌依次为大肠杆菌、肺炎克雷伯菌、金黄色葡萄球菌、卡他莫拉菌、表皮葡萄球菌和肺炎链球菌。从成人中分离得到致病菌2288株,其中G＋菌743株,占32.47%,G-菌1545株,占67.53%;数量居前6位的分离细菌依次为大肠杆菌、肺炎克雷伯菌、金黄色葡萄球菌、鲍曼不动杆菌、铜绿假单胞菌和肠球菌属。在儿童与成人两组病人中,耐甲氧西林金黄色葡萄球菌（MRSA）的检出率分别为13.9%和19.4%。从儿童中分离的大肠杆菌和肺炎克雷伯菌对阿米卡星和喹诺酮类药物的耐药率要远低于成人,铜绿假单胞菌和鲍曼不动杆菌对抗菌药物的耐药率低于成人,特别是对氨基糖苷类和喹诺酮类药物。结论：儿童常见病原菌的分布和耐药特点与成人存在一定的差异,应持续地进行细菌耐药监测。     

儿童肺炎患者碳青霉烯耐药肠杆菌的临床特征分析

目的：探讨儿童肺炎碳青霉烯耐药肠杆菌耐药机制和临床传播特征,分析医院感染防控措施及经验。方法：收集江苏省徐州市中心医院2017年8月至2019年10月收治的216例儿童肺炎患者中分离的46株非重复碳青霉烯耐药肠杆菌科细菌,并进行菌株鉴定、药敏试验、基因检测、同源性、传播特征及相关临床资料分析,根据脉冲场凝胶电泳（PFGE）分型将肺炎克雷伯菌携带blaNDM-1基因的儿童肺炎患者分为A型组和非A型组,并对相关数据进行统计学分析。结果：儿童肺炎患者碳青霉烯耐药肠杆菌主要包括肺炎克雷伯菌25株（54.35%）、大肠埃希菌7株（15.22%）、阴沟肠杆菌4株（8.70%）、产酸克雷伯菌4株（8.70%）、弗劳地枸橼酸杆菌3株（6.52%）及粘质沙雷菌3株（6.52%）。碳青霉烯耐药肠杆菌对阿米卡星敏感率为86.10%,对头孢唑林、头孢他啶、头孢曲松、厄他培南、美罗培南、亚胺培南和头孢哌酮/舒巴坦耐药率分别为100.00%、100.00%、100.00%、100.00%、97.70%、95.30%及95.30%。碳青霉烯耐药肠杆菌经改良Hodge试验和乙二胺四乙酸（EDTA）协同试验阳性率分别为58.70%及36.97%,聚合酶链式反应（PCR）检测携带blaKPC-2基因者27株（58.70%）,携带blaNDM-1基因者16株（34.78%）,携带blaIMP-4基因者1株（2.17%）。13株携带碳青霉烯耐药blaNDM-1基因的肺炎克雷伯菌PFGE分型为A型7株,B型2株,C、D、E、F型各1株。A型组和非A型组患儿重症监护室（ICU）住院史和住院时间≥30 d比较差异有统计意义（P<0.05）。结论：儿童肺炎患者碳青霉烯耐药肠杆菌呈多重耐药,耐药机制主要缘于碳青霉烯酶基因克隆传播,且与患儿ICU住院史和住院时间延长有关,临床应加强医院感染防控措施以预防耐药菌传播。     

Antimicrobial susceptibilities and analysis of genes related to penicillin or macrolide resistance in Streptococcus pneumoniae

One hundred and seventy-seven strains of Streptococcus pneumoniae derived from respiratory specimens between 1987 and 2001 were evaluated for their antimicrobial susceptibilities and distribution of genes related to penicillin and macrolide resistance. Resistance rates tended to be higher for the 1996-2001 isolates than for the 1987-1995 isolates for all beta-lactams tested. For benzylpenicillin the MIC(90) value of the isolates derived between 1996 and 2001 was 1.56 mg/L, while that of strains isolated between 1987 and 1990 was 0.05 mg/L. Furthermore, the number of strains susceptible to macrolides also decreased, but only two strains isolated in 1993 were resistant to levofloxacin of the 177 S. pneumoniae strains tested. When of genes relating to penicillin resistance were analysed using PCR with primers specific to susceptible alleles, although more than 50% of strains from 1987 to 1990 and 1991 to 1995 revealed no mutations in the pbp 1a, 2x and 2b genes, only 30.0% of strains derived between 1996 and 2001 showed no mutations in the pbp gene. Strains having mutations in all three pbp genes (1a, 2x and 2b) by the PCR method increased from only 2.2% in the 1987-1990 derived strains to 27.5% in the 1996-2001 strains. Furthermore, 64.1 and 60.0% of the isolates from 1987 to 1990 and 1991 to 1995, respectively, did not possess either the mefA or ermB by PCR analysis. Conversely, 75.0% of isolates from 1996 to 2001 possessed mefA and/or ermB. These genetic changes may explain the increase in the number of penicillin and macrolide resistant strains. We believe that it is important to evaluate changes in MIC as well as genetic mutations in order to select the most appropriate therapy for S. pneumoniae infections.     

Epidemiological analysis of Streptococcus pneumoniae in Gifu prefecture

Since antimicrobial resistance in Streptococcus pneumoniae become serious problem, we have conducted the epidemiological analysis of Streptococcus pneumoniae in Gifu prefecture. We have investigated the mutations of penicillin-binding protein (PBP) cording genes, the mutations of macrolide-resistant cording genes, and antimicrobial susceptibility using broth microdilution method, for 345 strains isolated from clinical specimens between May 2006 and July 2006 at 12 clinical facilities of 5 medical area. The ratio of penicillin-susceptible S. pneumoniae (gPSSP), penicillin-intermediate S. pneumoniae (gPISP), and penicillin-resistant S. pneumoniae (gPRSP), which were judged by molecular techniques, were 7.2%, 53.5%, and 39.4%, respectively. Only 1 gPSSP strain was isolated from children under three years old. There have been regional differences of the isolation rate of gPRSP between Gifu/Chuno area (55-60%) and Tono/Hida area (23-32%) in second- or third-medical facilities. The isolation rate of PBP mutation genes, pbp2x, pbp1a and pbp2b, were 92.8%, 52.5% and 53.3%, respectively. The isolation rate of macrolide-resistant cording genes, mefA only, ermB only, and both mefA and ermB, were 30%, 50% and 8%, respectively. The strains of S. pneumoniae with both mefA and ermB mutations, increased from 4% in 2002 to 8% in 2006. The antimicrobial susceptibility of S. pneumoniae to penicillin G (PCG) showed two peaks around 0.03 and 1 microg/mL, and 89% of S. pneumoniae with minimum inhibitory concentration (MIC) value 1 microg/mL was gPRSP. The MIC values of PCG against 69% strains of gPRSP distributed between 0.25 and 1 microg/mL. There have been the decreased tendency for the differences among medical facilities in penicillin resistant strains. Although cefditoren showed the most effective antimicrobial activity in oral cephems tested, there have been the strains with MIC value of over 1 microg/mL. The MIC90 of panipenem was 0.125 microg/mL, which was the best antimicrobial activity in carbapenems. The resistant rates of clarithromycin and azithromycin were 85% and 84%, respectively. The strains with the gene mutation of ermB have showed resistant to clindamycin. The MIC90 of tosufloxacin was 0.25 microg/mL, which was the best antimicrobial activity in quinolones. We have detected 4 levofloxacin highly resistant S. pneumoniae, of which MIC value was over 32 microg/mL. Also, we have encountered the episode of the spread of S. pneumoniae in one family, which was clarified by scientific approach.     

Antimicrobial susceptibilities and distribution of resistance genes for beta-lactams and macrolides in Streptococcus pneumoniae isolated between 2002 and 2004 in Tokyo

Antimicrobial susceptibilities of 205 Streptococcus pneumoniae strains isolated between 2002 and 2004 in Japan were examined and the distribution of genes for resistance to penicillins and macrolides were investigated by polymerase chain reaction. The molecular epidemiology of 92 randomly selected isolates was also examined by pulsed-field gel electrophoresis (PFGE). The numbers of S. pneumoniae isolates resistant to benzylpenicillin, clarithromycin and tetracycline were, respectively, 39 (19%), 111 (54%) and 155 (76%), and the numbers increased annually. All isolates were susceptible to amoxicillin, fluoroquinolones, vancomycin and linezolid. Analysis of mutations in the genes for penicillin-binding protein showed that 92% of isolates had mutations in pbp1a, pbp2b and/or pbp2x. Susceptibility to benzylpenicillin decreased with increasing number of mutated pbp genes. The macrolide resistance genes ermB and mefA were found in 99 (48%) and 76 (37%) isolates, respectively. The presence of ermB was associated with high-level resistance to macrolides, and the percentage of isolates with ermB increased annually. The presence of mefA also increased with increasing number of mutated pbp genes. Although the 92 isolates belonged to 74 PFGE types, three groups with an 80% similarity in their PFGE patterns were found at high frequency. Two of the three groups contained no isolates susceptible to penicillin and/or tetracycline, and their percentages increased annually. Our results suggest that the number of S. pneumoniae isolates with reduced susceptibility due to accumulation of resistance genes has been increasing.     

铜绿假单胞菌III型分泌系统相关毒力基因在抗菌药物中表达差异的研究

目的 分析临床分离铜绿假单胞菌Ⅲ型分泌系统(type III secretion system, T3SS)毒力基因exoS、exoU在抗菌药物中表达的差异性，以期为患者选择合适的抗感染治疗方案及预后评估提供依据。方法 选取南昌大学第二附属医院2017年1月-2017年12月临床分离的铜绿假单胞菌72株，采用Vitek2 Compact全自动微生物鉴定仪进行细菌鉴定及药敏，采用PCR法检测分离菌株T3SS特异性片段popB和相关毒力基因exoS、exoU表达情况；收集患者临床信息，了解毒力基因表达与细菌耐药性的关系。结果 72株铜绿假单胞菌中4种基因型exoS+/exoU-、exoS-/exoU+、exoS+/exoU+和exoS-/exoU-，分别为56.94%、26.39%、4.17%和12.50%，其中痰液、血液标本中检出率最高的基因型为exoS+/exoU-，分别为57.50%(23/40)和70.00%(7/10)。分析药敏结果显示，亚胺培南、氨基糖苷类和氟喹诺酮类耐药的分离株中携带exoU基因的耐药率显著高于携带exoS基因的耐药率，具有统计学意义(P<0.05)；其中携带exoU基因的总菌株为22株，其对亚胺培南、庆大霉素、妥布霉素、阿米卡星、左氧氟沙星及环丙沙星的耐药率分别为45.45%、45.45%、50.00%、50.00%、40.91%和40.91%；携带exoS基因的总菌株为44株，其对以上药物的耐药率分别为4.55%、6.82%、4.55%、18.18%、11.36%和18.18%。结论 我院临床分离的铜绿假单胞菌毒力基因以exoS+/exoU-基因型为主；铜绿假单胞菌携带exoU基因时，显示出对亚胺培南、氨基糖苷类和氟喹诺酮类抗菌药物具有更高的耐药性。     

2014-2016年邯郸市中心医院细菌耐药性监测结果分析

目的 了解2014-2016年邯郸市中心医院临床所分离细菌对抗菌药物的耐药性。方法 收集2014年1月1日-2016年12月31日邯郸市中心医院临床所分离的细菌,只分析同一患者同一部位的第一株菌。采用Vitek2-Compact和珠海美华MA120进行鉴定,药敏试验方法采用MIC和KB法,并采用WHONET 5.6软件进行统计分析。结果 邯郸市中心医院2014-2016年分离的菌株分别为3237、4484和4778株,共12499株细菌,其中革兰阴性菌8780株,占70.2%,革兰阳性菌3719株占29.8%。耐甲氧西林金黄色葡萄球菌(MRSA)和耐甲氧西林凝固酶阴性葡萄球菌(MRCNS)的检出率分别为38.38%和65.07%。屎肠球菌对绝大多数所测抗菌药物的耐药率明显高于粪肠球菌,葡萄球菌属和肠球菌属中均未发现万古霉素、替考拉宁和利奈唑胺耐药的菌株。肺炎链球菌以非脑脊液来源为主,成人多于儿童,且儿童分离株对青霉素均敏感,成人分离株青霉素耐药率为1.2%。大肠埃希菌和肺炎克雷伯菌超广谱β-内酰胺酶(ESBL)的检出率分别为49.4%和28.3%,对碳青霉烯类药物耐药率分别为1.8%和4.4%。铜绿假单胞菌对亚胺培南和美罗培南的耐药率分别为20.3%和13.6%,鲍曼不动杆菌对亚胺培南和美罗培南的耐药率分别为63.8%和63.7%。结论 3年间细菌耐药性发生了变化,医生应该依据药敏监测结果合理选择抗菌药物。     

Alterations in penicillin binding protein gene of Streptococcus pneumoniae and their correlation with susceptibility patterns

Penicillin binding protein (pbp) gene alterations of 328 clinical isolates of Streptococcus pneumoniae were examined for a correlation with their antibiotic-resistance. The frequency of penicillin G (PEN-G) resistance was determined to clarify susceptibility to several antibiotics, namely PEN-G, ampicillin, sulbactam/ampicillin, cefozopram, panipenem (PAPM), clarithromycin (CLR), azithromycin (AZM) and levofloxacin (LVX). Oligonucleotide primers for three pbp genes (pbp1a, pbp2x and pbp2b) were used to detect mutations in pbp. Of the strains, 25.9% were classified as Pen-Gs, 68.0% as Pen-Gir and 6.1% as Pen-Gr. The polymerase chain reaction product for wild-type pbp1a was found in 185 isolates, that for wild-type pbp2x was found in 66 isolates and that for wild-type pbp2b was found in 213 isolates. None of these three genes was detectable in 100 isolates while all of them were detected in 64 isolates (1aw/2xw/2bw). Of those 64 isolates with 1aw/2xw/2bw, the minimum inhibitory concentration (MIC) of PEN-G was < or =0.06 mg/l for 54 isolates and 0.12 mg/l for 10 isolates. Of the 272 strains for which the MIC of PAPM was < or =0.03 mg/l, there were 85 Pen-Gs, 184 Pen-Gir and three Pen-Gr isolates. Three strains for which the MIC of LVX was > or =4.0 mg/l included one Pen-Gs and two Pen-Gir isolates. The MICs of CLR correlated significantly with those of AZM. The MIC of CLR was > or =1 mg/l for 216 isolates, and the MIC of AZM was > or =1 mg/l for 244 of them. These data suggested that PAPM may be effective against S. pneumoniae infection, although acquisition of resistance should be considered. LVX also seemed to be effective against S. pneumoniae.     

Epidemiological analysis of Streptococcus pneumoniae in Gifu prefecture and the northern district of Aichi prefecture--2009

High pathogenicity and drug resistance of Streptococcus pneumoniae are serious problem in clinical practice. Since 1999, we have conducted epidemiologic analyses of S. pneumoniae in Chubu district. We report the results of the analysis conducted in 2009. Three hundred and eight (308) S. pneumoniae isolates with a gene coding for autolysin lyt-A, which had been isolated from patients at 21 medical institutions in Gifu prefecture and the northern part of Aichi prefecture in 2009, were enrolled in this study. The strains were classified according to their drug resistance based on the presence of the pbp mutation, and examined for the presence of the two macrolide-resistance genes, ermB and mefA. Moreover, they were serotyped using type-specific antisera. The mean age of the patients from whom these S. pneumoniae strains were isolated, was 23.4 +/- 30.1 years old, and children aged 15 years old or less accounted for 66% of all the patients. Genotype penicillin-susceptible S. pneumoniae (gPSSP), genotype penicillin-intermediate S. pneumoniae (gPISP) and genotype penicillin-resistant S. pneumoniae (gPRSP) were 22 (7.1%), 131 (42.5%) and 155 (50.3%), respectively. The strains with mefA positive and ermB negative, mefA negative and ermB positive, and mefA positive and ermB positive were 80 (26.0%), 153 (49.7%), and 47 (15.3%), respectively. The MIC90 values of tebipenem (TBPM) and faropenem were 0.06 microg/mL and 0.5 microg/mL, respectively. TBPM showed the high bactericidal activity against gPRSP. In carbapenems, panipenem and biapenem exhibited higher bactericidal activities. Quinolone-resistant S. pneumoniae (QRSP) were isolated from 10 (3.2%). QRSP dominated 5 (7.9%) and 3 (1.5%) among the elderly (over 65 years old) and children, respectively. (As for the serotype, serotypes 6, 19 and 23 were 60 (19.5%), 62 (20.1%), and 44 (14.3%), respectively. Further epidemiologic studies on S. pneumoniae might be required also in the future, including the relationship between the serotype and drug resistance.