2008-2009年中国部分地区脑膜炎奈瑟菌对体外抗生素敏感性检测

目的了解2008-2009年中国部分地区脑膜炎奈瑟菌(Nm)分离株的抗生素敏感性变化趋势。方法药敏纸片扩散(K-B)法和E-test试纸条检测方法对本研究室2008-2009年收集的68株分离自患者和健康带菌者菌株进行体外抗菌药物敏感性检测。结果所有菌株对3种治疗药物头孢噻肟、头孢曲松和氯霉素均敏感,1株C群患者菌株对美洛培南耐药,13株对青霉素不敏感菌株,6株对氨苄西林不敏感菌株。6种预防用药组中,除1株Y群带菌者菌株对利福平耐药外,其他菌株对阿奇霉素、米诺环素和利福平均敏感,70.59%菌株对萘啶酸,72.06%对环丙沙星,95.59%对复方新诺明耐药。W135群带菌者菌株对青霉素和氨苄西林敏感株比例较大,2株对磺胺类药物敏感。患者菌株和带菌者菌株药敏谱略有不同。结论磺胺类和喹诺酮类药物仍不被考虑作为流脑的预防性药物,加强对青霉素和氨苄西林治疗药物在各种血清群Nm的耐药性监测。长期对Nm药敏监测非常必要,对流行性脑脊髓膜炎预防和治疗药物的选择应因时因地而宜。     

2003-2012年中国部分地区脑膜炎奈瑟菌体外抗生素敏感性分析

目的 了解我国脑膜炎奈瑟菌对抗生素敏感性的变化趋势. 方法 对2003-2012年本研究室收集的脑膜炎奈瑟菌菌株,根据分离年份、血清群和来源(患者或健康携带者)选择487株,采用微量肉汤稀释法和E-test浓度梯度扩散法,对其进行体外12种抗生素敏感性检测和分析. 结果 所有菌株对头孢噻肟、头孢曲松、阿奇霉素、美洛培南、氯霉素和米诺环素均敏感;对青霉素和氨苄西林不敏感的菌株分别是4.9%(24/487)和3.5%(17/487),75.6%(368/487)的菌株对萘啶酸耐药,87.1%(424/487)对复方新诺明耐药,48.9%(238/487)对环丙沙星耐药.从2005年开始出现对环丙沙星耐药的菌株23.8%(24/101),从2006年开始出现对青霉素类药物不敏感菌株2.4%(2/82).患者和健康携带者来源的菌株对萘啶酸、复方新诺明和环丙沙星3种药物显现不同的耐药率. 结论 我国流脑菌株对磺胺类和喹诺酮类药物具有较高的耐药性,对青霉素类药物不敏感的菌株也逐渐增多.这种耐药性与菌株分离年份、血清群和菌株来源具有相关性.     

2006年浙江省流行性脑脊髓膜炎监测结果分析

目的 了解2006年浙江省流脑流行病学特征及流脑菌株的药物敏感性特点.方法 对2006年全省上报的流脑病例进行描述流行病学分析.设立3个监测点进行健康人群抗体水平和带菌率检测,并对分离到的流脑菌株进行抗生素的耐药性检测.结果 2006年浙江省流脑发病率为0.16/10万,病例以A群为主,同时存在C群和B群病例.健康人群中A群抗体保护率(70.65%)远远高于C群(6.52%),流脑菌株带菌率为1.71%,B群占62.50%.所有菌株均对青霉素、氯霉素等9种抗生素敏感,部分菌株对复方新诺明、左氧氟沙星、环丙沙星耐药,且不同血清群、不同来源菌株的耐药程度不同.结论 浙江省流脑病例以A群为主,C群比例有上升趋势.流脑菌株对一些抗生素具有耐药性,需全面监测病例和健康带菌者流脑菌株的耐药性特征.     

脑膜炎奈瑟氏菌对常用抗菌药物敏感性监测

本文就1966～1993年21个省市分离的218株A、B和C群脑膜炎奈瑟氏菌(Nm)对7种常用抗菌药物的敏感性进行了监测。在108株A群Nm中20株(18.5％)对SMZ耐药，其中17.3％的病人菌株，21.2％的带菌者菌株耐药；31株(28.7％)对ASP耐药。在101株B群Nm中40株(39.6％对SMZ耐药，其中43.3％的病人菌株和34.1％的带菌者菌株耐药，17株(16.8％)对ASP，10株(9.9％)对cF耐药。在9株c群Nm巾5株对SMZ，2株对ASP耐药。未发现Nm对Chl耐药。实验结果提示我们今后在流脑治疗和化学预防上应加强Nm对抗菌药物敏感性的监测，这有助于提高这些药物对流脑防治的效果。     

2008－2017年鄂西北地区脑膜炎奈瑟菌药物敏感性及分子分型研究

目的 分析鄂西北地区2008 – 2017年分离到的72株脑膜炎奈瑟菌（Nm）的药物敏感性及分子分型特征。 方法 对Nm菌株进行生化鉴定和血清学分群,并采用荧光聚合酶链式反应进行基因分群,用K-B纸片和E-test检测试纸条进行药敏试验;选取部分菌株进行多位点序列分型（MLST）和脉冲场凝胶电泳（PFGE）。 结果 血清分群结果为B群14株、C群10株、W群3株、E群1株、不可分群44株。基因分群结果:B群33株、C群10株、W群3株、E群1株,其他及不可分群25株。70株Nm菌株对复方新诺明、萘啶酸、环丙沙星、米诺环素、氯霉素5种抗生素的敏感率分别为7.14%、21.43%、28.57%、98.57%和98.57%,对美罗培南、亚胺培南、阿奇霉素、头孢曲松、头孢噻肟、青霉素和利福平均敏感。17株菌株共有12种序列型别,其中12株菌株不能归入现有克隆群,其他5株属于CC4821（4株）和CC175（1株）。55株菌株分为48种不同的PFGE带型,带型相同的菌株其基因群亦相同。 结论 2008 – 2017年鄂西北地区分离的Nm菌株主要为B群;对复方新诺明、萘啶酸和环丙沙星具有较高的耐药性。MLST分型以CC4821为优势克隆。PFGE分型特征呈多态性,未出现优势带型。      

2005-2014年上海市O139群霍乱弧菌的分子特征和耐药性研究

目的 分析2005-2014年上海市O139群霍乱弧菌的分子特征和耐药性。方法 以聚合酶链反应(PCR)方法检测86株O139群霍乱弧菌的霍乱毒素基因(ctxA)、溶血素基因(hlyA)、毒素协调菌毛基因(tcpA)、调控蛋白基因(toxR)和编码霍乱毒素基因的CTX基因组基因(zot、ace)。采用脉冲场凝胶电泳(PFGE)和多位点序列分型(MLST)方法对O139群霍乱弧菌菌株进行分子分型。采用WHO推荐的改良K-B纸片法,对O139群霍乱弧菌菌株进行11种抗菌药物(头孢曲松、强力霉素、诺氟沙星、环丙沙星、复方新诺明、丁胺卡那霉素、四环素、氯霉素、萘啶酸、氨苄西林、庆大霉素)敏感试验。结果 患者来源O139群霍乱弧菌菌株93.2%(41/44)为产毒株,水产来源菌株58.3%(21/36)为产毒株,6株水体来源菌株均为非产毒株。PFGE分析将O139群霍乱弧菌分为35个型别。MLST分析将O139群霍乱弧菌分为9个ST型,其中流行菌型为ST 69型,非产毒株以ST 162型为主。86株O139群霍乱弧菌经药物敏感试验分析显示O139群霍乱弧菌产毒株的耐药情况比非产毒株严重。O139群霍乱弧菌产毒株对强力霉素、复方新诺明、四环素、萘啶酸、氨苄西林、庆大霉素的耐药率高。O139群霍乱弧菌非产毒株对萘啶酸耐药严重。结论 上海市患者和水产来源O139群霍乱弧菌构成以产毒株为主。PFGE分型提示水产为霍乱疫情的主要传染源。O139群霍乱弧菌产毒株高度克隆化,流行菌型为ST 69型,耐药情况严重。     

云南省玉溪市甲型副伤寒沙门菌对抗生素的敏感性分析

目的 了解云南省玉溪市甲型副伤寒沙门菌(Salmonella paratyphi A, SPA)对抗生素的敏感性及耐药趋势,为临床医生合理用药、有效治疗患者、清除传染源提供依据。 方法 采用纸片K-B法扩散技术检测玉溪市2005-2011年分离的252株SPA对17种抗生素的敏感性;并采用 Etest测试条进行喹诺酮类(萘啶酸、环丙沙星、左氧氟沙星、诺氟沙星)抗生素最低抑菌浓度(minimum inhibitory concentration,MIC)测定。 结果 分离株对氨苄西林、阿莫西林、头孢噻吩、亚胺培南、奈替米星、复方新诺明、氯霉素7种抗生素均敏感;头孢噻肟的敏感率为99.21%;四环素、氨曲南、左氧氟沙星的敏感率为98.41%;呋喃妥因、诺氟沙星、环丙沙星的敏感率分别为97.62%、95.63%和36.51%;洛美沙星、萘啶酸的敏感率仅为0.79%,所有分离株对利福平耐药;分离株对洛美沙星的中介率逐年下降,耐药率逐年上升;对环丙沙星的中介率不断上升,敏感性不断降低。250株分离株属于萘啶酸抗性(nalidixic acid-resistant,NAR)株,其余2株属于萘啶酸敏感(nalidixic acid-sensitive, NAS)株, NAR株降低了对氟喹诺酮类药物的敏感性,NAR分离株MIC值远远高于NAS株的MIC(χ2=244.063, P结论 第三代头孢菌素可作为玉溪境内治疗甲型副伤寒的首选药物;当地SPA对氟喹诺酮类抗生素耐药性呈上升趋势,合理应用该类药物,对遏制耐药性的进一步发展,具有十分重要的意义。     

大肠埃希菌临床感染分布特征及耐药性分析

目的了解川北地区大肠埃希菌的临床分布特征及耐药情况。方法收集临床分离的大肠埃希菌180株,用双纸片表型确证试验检测产超广谱β-内酰胺酶(ESBLs)菌株,琼脂稀释法进行药物敏感试验,敏感、中介、耐药及ESBLs阳性菌株的判定采用美国临床实验室标准化协会(CSLI)2006年公布的标准。结果在180株大肠埃希菌中,来自尿液、痰液、伤口分泌物和急诊病房标本的比率较高。180株大肠埃希菌对氨苄西林、环丙沙星、左氧氟沙星、庆大霉素、复方新诺明、头孢唑林、妥布霉素、氨苄西林/舒巴坦、头孢曲松的耐药率高达32.9%～92.3%。ESBLs阳性大肠埃希菌对氨苄西林/舒巴坦、头孢唑林、头孢曲松的耐药率显著高于ESBLs阴性菌株,ES-BLs阳性大肠埃希菌除增强了对β-内酰胺类抗菌药物耐药外,还表现出对喹诺酮类药物环丙沙星、左氧氟沙星以及氨基糖苷类抗菌药物庆大霉素更高的耐药率。结论川北地区大肠埃希菌主要分布在急诊病房以及尿液、痰液、伤口分泌物标本中,且对临床常用抗菌药物耐药突出,提示临床医生必须加强对该菌感染治疗的合理用药。     

太原市2006年分离志贺菌菌株的血清分型及耐药性分析

目的 调查太原市分离的志贺菌菌株的主要血清型和对常用抗菌药物的耐药性.方法 对从腹泻患者分离的志贺菌菌株进行血清分型、生化鉴定和药物敏感试验.结果 129份腹泻样本分离出阳性菌株40株,其中福氏志贺菌33株,占分离菌株的82.5%,宋内志贺菌7株,占分离总数的17.5%;福氏志贺菌中,4c 型21株,占63.6%.福氏志贺菌对萘啶酸100%耐药,对氨苄西林、四环素耐药性均为97%,对头孢噻肟、庆大霉素的药物敏感性均为97%.宋内志贺菌对萘啶酸、四环素、复方新诺明均100%耐药;对阿莫西林、头孢噻肟、环丙沙星的敏感性均为100%.结论 2006年太原市志贺菌优势菌型为福氏志贺菌4c型,志贺菌不同血清型对几种常用抗菌药物出现不同程度的耐药性.     

2006-2011年浙江省杭州市萧山区流感嗜血杆菌耐药性监测

目的 调查了解流感嗜血杆菌的临床分布及耐药情况,为临床用药提供依据。 方法 对2006年1月至2011年12月浙江萧山医院临床分离的流感嗜血杆菌,用ATB嗜血杆菌药敏板条测定抗菌药物的敏感性, 用头孢硝噻吩纸片法测定-内酰胺酶,所有数据用WHONET 5.6软件进行回顾性分析。 结果 共检出流感嗜血杆菌375株,对复方新诺明、氨苄西林耐药分别为248株(66.1%)和127株(33.8%),对氯霉素、头孢克洛和四环素耐药分别为38株(10.2%)、52株(13.8%)和55株(14.7%);其他几种常用药物阿莫西林/克拉维酸、头孢呋辛、头孢噻肟、利福平和氧氟沙星对流感嗜血杆菌保持较好的抗菌活性(耐药率5.0%);-内酰胺酶阳性菌株对多种药物的耐药率显著高于阴性菌株(P0.01)。 结论 复方新诺明耐药率高而不宜用于流感嗜血杆菌感染的治疗, 氨苄西林应慎重用于经验治疗;流感嗜血杆菌对氨苄西林耐药率呈下降趋势,对二代头孢菌素耐药率呈上升趋势,临床应根据药敏结果合理使用抗菌药物。     

空肠弯曲菌耐药谱特征分析

目的 分析十几年间我国空肠弯曲菌临床分离株对10种抗生素耐药谱特征,了解我国空肠弯曲菌耐药的变迁趋势。 方法 采用世界卫生组织(WHO)全球食源性病原菌感染网络(GFN)推荐的弯曲菌琼脂稀释法,测定1995年至今分离的116株空肠弯曲菌对6类10种抗生素的最小抑菌浓度(MIC)。 结果 经对实验结果整体分析,甲硝唑的总体耐药率最高为97.4%(113/116),四环素为82.8%(96/116),环丙沙星为80.2%(93/116),萘啶酸为79.3%(92/116),左氧氟沙星和氨苄西林耐药率相同,为40.5%(47/116),氯霉素为18.1%(21/116),庆大霉素为8.6%(10/116),链霉素为4.3%(5/116),最低为红霉素0(0/116)。随着时间的推进,萘啶酸、环丙沙星、左氧氟沙星和氨苄西林的MIC有明显增高趋势;四环素、红霉素、庆大霉素、氯霉素和甲硝唑的MIC值变化不明显;链霉素的MIC值变化有下降的趋势。6.1%的菌株出现了8种抗生素多重耐药的结果,且菌株均出现在2010年后。经统计学分析,萘啶酸、环丙沙星、链霉素、庆大霉素、氯霉素和氨苄西林6种抗生素在2001年前、2001-2005年、2006-2010年和2010年后4个时间段中耐药率差异有统计学意义。 结论 空肠弯曲菌对红霉素、庆大霉素以及链霉素3种抗生素依旧保持了较高的敏感性,对萘啶酸、环丙沙星、左氧氟沙星、四环素、甲硝唑以及氨苄西林6种抗生素产生了较大程度的耐药。     

Emergence of fluoroquinolone resistance among multiply resistant strains of Streptococcus pneumoniae in Hong Kong

The MICs of 17 antimicrobial agents for 181 Streptococcus pneumoniae strains were determined by the E-test. Overall, 69.1% were penicillin resistant (MIC > 0.06 microgram/ml). Resistance to ciprofloxacin (MIC > 2 microgram/ml), levofloxacin (MIC > 2 microgram/ml), or trovafloxacin (MIC > 1 microgram/ml) was found in 12.1, 5.5, or 2.2% of the strains, respectively. These high rates of resistance raise concerns for the future.     

Antipneumococcal activity of DK-507k, a new quinolone, compared with the activities of 10 other agents

Agar dilution MIC determination was used to compare the activity of DK-507k with those of ciprofloxacin, levofloxacin, gatifloxacin, moxifloxacin, sitafloxacin, amoxicillin, cefuroxime, erythromycin, azithromycin, and clarithromycin against 113 penicillin-susceptible, 81 penicillin-intermediate, and 67 penicillin-resistant pneumococci (all quinolone susceptible). DK-507k and sitafloxacin had the lowest MICs of all quinolones against quinolone-susceptible strains (MIC at which 50% of isolates were inhibited [MIC50] and MIC90 of both, 0.06 and 0.125 microg/ml, respectively), followed by moxifloxacin, gatifloxacin, levofloxacin, and ciprofloxacin. MICs of beta-lactams and macrolides rose with those of penicillin G. Against 26 quinolone-resistant pneumococci with known resistance mechanisms, DK-507k and sitafloxacin were also the most active quinolones (MICs, 0.125 to 1.0 microg/ml), followed by moxifloxacin, gatifloxacin, levofloxacin, and ciprofloxacin. Mutations in quinolone resistance-determining regions of quinolone-resistant strains were in the usual regions of the parC and gyrA genes. Time-kill testing showed that both DK-507k and sitafloxacin were bactericidal against all 12 quinolone-susceptible and -resistant strains tested at twice the MIC at 24 h. Serial broth passages in subinhibitory concentrations of 10 strains for a minimum of 14 days showed that development of resistant mutants (fourfold or greater increase in the original MIC) occurred most rapidly for ciprofloxacin, followed by moxifloxacin, DK-507k, gatifloxacin, sitafloxacin, and levofloxacin. All parent strains demonstrated a fourfold or greater increase in initial MIC in <50 days. MICs of DK-507k against resistant mutants were lowest, followed by those of sitafloxacin, moxifloxacin, gatifloxacin, ciprofloxacin, and levofloxacin. Four strains were subcultured in subinhibitory concentrations of each drug for 50 days: MICs of DK-507k against resistant mutants were lowest, followed by those of sitafloxacin, moxifloxacin, gatifloxacin, levofloxacin, and ciprofloxacin. Exposure to DK-507k and sitafloxacin resulted in mutations, mostly in gyrA.     

北京地区脑膜炎奈瑟菌耐药性监测

目的对北京地区脑膜炎奈瑟菌进行耐药性监测。方法采用临床及试验标准协会推荐的肉汤稀释法，测定12种抗菌药物的最低抑菌浓度。结果2004年11月至2006年3月收集的67株菌株对头孢曲松、阿奇霉素、头孢噻肟、美洛培南和利福平敏感，对甲氧苄啶/磺胺耐药。全部菌株对青霉素、氨苄西林和氯霉素均不耐药，但是分别有41、7和11株耐药性介于中介值；对环丙沙星有5株敏感，19株介于中介，43株耐药（占64．2％）；对左氧氟沙星有8株敏感，3株介于中介，56株耐药（占83．6％）；对四环素有19株敏感，3株介于中介，45株耐药（占67．2％）。结论青霉素、氨苄西林、头孢曲松、氯霉素、头孢噻肟和美洛培南仍是治疗流行性脑脊髓膜炎（流脑）的有效抗生素，而利福平和阿奇霉素可作为密切接触者的预防性用药。     

Mupirocin resistance in methicillin-resistant Staphylococcus aureus clinical isolates in a Spanish hospital. Co-application of multiplex PCR assay and conventional microbiology methods

A total of 33 Stenotrophomonas maltophilia clinical isolates were tested for their susceptibility to clinafloxacin in comparison with ciprofloxacin, levofloxacin, moxifloxacin, nalidixic acid, norfloxacin, sparfloxacin and trovafloxacin. The MIC(50) and MIC(90) were as follows: ciprofloxacin 4 and 64 microg/mL; clinafoxacin 0.5 and 4 microg/mL; levofloxacin 2 and 32 microg/mL; moxifloxacin 1 and 8 microg/mL; nalidixic acid 8 and 128 microg/mL; norfloxacin 64 and 256 microg/mL; sparfloxacin 1 and 16 microg/mL; and trovafloxacin 1 and 8 microg/mL. Clinafloxacin was the most active quinolone, with only a 15.1% of strains showing resistance. When the MICs were determined in the presence of 25 microg/ml of reserpine, the MIC(90) of trovafloxacin and moxifloxacin did not change, whereas decreased 2-fold for clinafloxacin, levofloxacin, sparfloxacin and nalidixic acid, and 4- and 8-fold for ciprofloxacin and norfloxacin respectively. No clinafloxacin-resistant strains were observed when the MIC was performed in the presence of reserpine. Therefore, clinafloxacin shows the better "in vitro"activity against these 33 strains of S.maltophilia.     

Molecular Characterization of Fluoroquinolone Resistance in Nontypeable Haemophilus influenzae Clinical Isolates

Nontypeable Haemophilus influenzae (NTHi) is a common cause of respiratory infections in adults, who are frequently treated with fluoroquinolones. The aims of this study were to characterize the genotypes of fluoroquinolone-resistant NTHi isolates and their mechanisms of resistance. Among 7,267 H. influenzae isolates collected from adult patients from 2000 to 2013, 28 (0.39%) were ciprofloxacin resistant according to Clinical and Laboratory Standards Institute (CLSI) criteria. In addition, a nalidixic acid screening during 2010 to 2013 detected five (0.23%) isolates that were ciprofloxacin susceptible but nalidixic acid resistant. Sequencing of their quinolone resistance-determining regions and genotyping by pulse-field gel electrophoresis and multilocus sequence typing of the 25 ciprofloxacin-resistant isolates available and all 5 nalidixic acid-resistant isolates were performed. In the NTHi isolates studied, two mutations producing changes in two GyrA residues (Ser84, Asp88) and/or two ParC residues (Ser84, Glu88) were associated with increased fluoroquinolone MICs. Strains with one or two mutations (n = 15) had ciprofloxacin and levofloxacin MICs of 0.12 to 2 μg/ml, while those with three or more mutations (n = 15) had MICs of 4 to 16 μg/ml. Long persistence of fluoroquinolone-resistant strains was observed in three chronic obstructive pulmonary disease patients. High genetic diversity was observed among fluoroquinolone-resistant NTHi isolates. Although fluoroquinolones are commonly used to treat respiratory infections, the proportion of resistant NTHi isolates remains low. The nalidixic acid disk test is useful for detecting the first changes in GyrA or in GyrA plus ParC among fluoroquinolone-susceptible strains that are at a potential risk for the development of resistance under selective pressure by fluoroquinolone treatment.     

In vitro activities of new fluoroquinolones against Campylobacter jejuni and Campylobacter coli isolates obtained from humans in 1980 to 1982 and 1997 to 2001

The antibacterial activities of three newly developed fluoroquinolones (gatifloxacin, levofloxacin, and moxifloxacin) against a total of 307 gastrointestinal human isolates of Campylobacter jejuni and Campylobacter coli collected during 1980 to 1982 and 1997 to 2001 were examined and compared to those of ciprofloxacin and the unrelated antibacterial agents, clarithromycin, erythromycin, and tetracycline by using the agar plate dilution method. All of the fluoroquinolones exhibited a good activity against Campylobacter, and some of them were more active than ciprofloxacin, the macrolides, and tetracycline. Among the fluoroquinolones, gatifloxacin and moxifloxacin showed the highest anticampylobacter activity, with MICs at which 50% of the isolates tested are inhibited (MIC(50)s) and MIC(90)s of 0.125 and 4 microg/ml, respectively; the MIC(50) for both levofloxacin and ciprofloxacin was 0.25, and the MIC(90)s were 16 and 32 microg/ml, respectively. About 30% of the strains were found to be resistant to at least one fluoroquinolone. Resistance to gatifloxacin occurred in 9.8% of the isolates tested, and resistance to the other fluoroquinolones occurred in 19.9 to 27.4% of the isolates tested; the frequency of cross-resistance was 35.7 to 100%. An increase in fluoroquinolone resistance from 0% in 1980 to 1982 to 11.8 to 29% in 1997 and 1998, 8.2 to 31.8% in 1999 and 2000, and 12.1 to 30.3% in 2001 was found. A total of 61.4 to 73.2% of the C. jenuni strains resistant to erythromycin, clarithromycin, and/or tetracycline were susceptible to fluoroquinolones; gatifloxacin showed the highest percentage of inhibition. These results show that the newer fluoroquinolones with their potent activity could be used to treat infections with C. jejuni and C. coli. However, when these drugs are used, one must consider the increase in resistance and the high cross-resistance to these antimicrobial agents.