中国西部某二级医院呼吸道感染住院患儿鼻咽部肺炎链球菌中常见非PCV13血清型菌株的横断面调查

目的：了解四川省中江县呼吸道感染住院患儿鼻咽部肺炎链球菌的定植状况及分离株的血清型分布和耐药性。方法：2015年1至12月采集四川省中江县人民医院儿科病房住院1月龄至14岁呼吸道感染患儿的鼻咽拭子并分离肺炎链球菌。用荚膜肿胀试验检测血清型,评估13价肺炎链球菌结合疫苗（PCV13）覆盖率。基于血清型随机选取约50%的菌株采用E test法或纸片扩散法检测青霉素等16种抗生素的敏感性。结果：共采集到1 082例鼻咽拭子,分离到肺炎链球菌199株,携带率18.4%。常见血清型为19F（14.6%）、19A（10.6%）、34（10.1%）、6A（9.0%）、23F（7.5%）、6B（7.5%）和23A型（7.0%）。PCV13覆盖率为54.8%。分离株对静脉青霉素敏感,但对口服青霉素敏感率仅为9.1%,对阿莫西林 克拉维酸敏感率为97%,对头孢曲松、万古霉素、左氧氟沙星和利奈唑胺敏感率100%,对红霉素和阿奇霉素均耐药。结论：四川省中江县呼吸道感染患儿鼻咽部常有肺炎链球菌定植;分离株中非PCV13型别常见,以34和23A型为多,有必要加强监测;分离株对口服青霉素和红霉素等耐药率高,但对静脉青霉素、头孢曲松和万古霉素等普遍敏感。     

中国西部单中心二级医院呼吸道感染住院患儿鼻咽部肺炎链球菌携带及其血清型和耐药性的横断面调查

目的 了解不发达地区二级医院呼吸道感染住院患儿鼻咽部肺炎链球菌的携带情况及分离株的血清型分布和耐药性特征。方法 采集重庆市酉阳土家族苗族自治县人民医院（简称酉阳医院）2015年1~12月呼吸道感染住院患儿鼻咽拭子标本,培养并分离肺炎链球菌,采用荚膜肿胀实验对分离株进行血清分型。随机选取50%的肺炎链球菌分离株以E-test法和纸片扩散法对16种常见抗菌药物检测其敏感性。结果 研究期间共采集鼻咽拭子标本1 054份,分离出肺炎链球菌267株,分离率为25.3%。≤5岁儿童分离率较高,冬春季分离率较高。267株肺炎链球菌分离株中最常见的血清型为19F型（47株,17.6%）,其次为6A（35株,13.1%）、14（31株,11.6%）、19A（28株,10.5%）、23F（28株,10.5%）和6B型（25株,9.4%）。13价肺炎链球菌结合疫苗（PCV13）的覆盖率为73.8%（197/267）。136株肺炎链球菌行抗生素药敏试验,所有菌株对头孢曲松、万古霉素和左氧氟沙星敏感,对利奈唑胺、亚胺培南和泰利霉素的敏感率较高,分别为96.3%、87.5%和84.5%;静脉青霉素的敏感率为100%,口服青霉素的敏感率为16.9%。99.3%（135/136)的分离株对红霉素和阿奇霉素耐药。PCV13覆盖株对口服青霉素、头孢吡肟、头孢呋辛和亚胺培南的不敏感率明显高于非PCV13覆盖株（P<0.01）。19A型菌株对口服青霉素、头孢吡肟不敏感率为100%。结论 酉阳医院呼吸道感染住院患儿鼻咽部肺炎链球菌的分离率为25.3%,常见血清型为19F、6A、14、19A、23F和6B,PCV 13覆盖率较高,且PCV13覆盖株对口服青霉素、头孢吡肟、头孢呋辛和亚胺培南的不敏感率明显高于非PCV13覆盖株。     

住院肺炎患儿不同血清型肺炎链球菌对抗菌药物的耐药性分析

目的 了解当前从我国住院肺炎儿童分离的肺炎链球菌血清型分布和不同血清型菌株对抗菌药物的耐药状况,评估应用疫苗预防儿童肺炎链球菌感染和控制耐药菌传播的价值。方法 肺炎链球菌分离自4家儿童医院呼吸科年龄 ≤ 5岁的住院肺炎患儿,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 279株肺炎链球菌中以19F型为最常见（占60.6%）,其次为19A（9.7%）。23F（9.3%）和6B（5.4%）,7价结合疫苗（PCV7）覆盖率为81.0%,PCV7在青霉素不敏感菌株和敏感菌株中的覆盖率分别为84.2%（202/240）和61.5%（24/39）。超过90%的19F和19A型菌株对青霉素不敏感,19F型以中介株为主（71.6%）,19A型以耐药株为主（55.6%）。结论 住院儿童肺炎病例分离的肺炎链球菌以19F。19A。23F和6B型常见;PCV7覆盖大多数肺炎链球菌和青霉素不敏感菌株,应用该疫苗可有效地预防国内儿童肺炎链球菌感染和阻止耐药菌株传播;非PCV7覆盖的19A型具有较强耐药性。     

北京地区上呼吸道感染儿童青霉素不敏感肺炎链球菌的血清型分布研究

目的 了解青霉素不敏感肺炎链球菌（PNSP）的耐药性和血清型分布。方法 以2000～2004年门诊上呼吸道感染的0～5岁患儿鼻咽部分离的肺炎链球菌为研究菌株,采用E-test法检测青霉素最低抑菌浓度,简易棋盘式分型系统进行血清分型。结果 检出PNSP菌株129株,其中中介102株,耐药27株;2000～2004年各年耐药株占PNSP比率分别为19．0％、8．0％、17．6％、30．0％和26．1％;常见血清型共有124株（96．1％）,为19群、23群、不能分型、6群和14型;7价结合疫苗覆盖率从2000年到2004年分别为57．1％、76．0％、88．2％、75．0％和82．6％。结论 北京儿童中分离的PNSP的青霉素耐药性有所增强;7价结合疫苗覆盖率升高,有利于应用疫苗来预防PNSP的携带、感染及耐药性的进一步播散。     

住院肺炎患儿不同血清型肺炎链球茵对抗菌药物的耐药性分析

目的 了解当前从我国住院肺炎儿童分离的肺炎链球萧血清型分布和不同血清型菌株对抗菌药物的耐药状况,评估应用疫苗预防儿童肺炎链球菌感染和控制耐药菌传播的价值.方法 肺炎链球菌分离自4家儿童医院呼吸科年龄≤5岁的住院肺炎患儿,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 279株肺炎链球菌中以19F型为最常见(占60.6%),其次为19A(9.7%)、23F(9.3%)和6B(5.4%),7价结合疫苗(PCV7)覆盖率为81.0%,PCV7在青霉素不敏感菌株和敏感菌株中的覆盖率分别为84.2%(202/240)和61.5%(24/39).超过90%的19F和19A型菌株对青霉素不敏感,19F型以中介株为主(71.6%),19A型以耐药株为主(55.6%).结论 住院儿童肺炎病例分离的肺炎链球菌以19F、19A、23F和6B型常见;PCV7覆盖大多数肺炎链球菌和青霉素不敏感菌株,应用该疫苗可有效地预防国内儿童肺炎链球菌感染和阻止耐药菌株传播;非PCV7覆盖的19A型具有较强耐药性.     

中国2岁以下健康婴幼儿鼻咽部携带常见病原菌的血清分型及耐药性分析

目的分析2岁以下健康婴幼儿鼻咽部携带肺炎链球菌的血清型特点,监测肺炎链球菌、流感嗜血杆菌、卡他莫拉菌对常规用药的体外敏感性。方法采用荚膜肿胀试验对肺炎链球菌进行血清分型,E-test法测定肺炎链球菌(451株)、流感嗜血杆菌(168株)、卡他莫拉菌(396株)的体外敏感性,头孢硝噻吩试验检测流感嗜血杆菌、卡他莫拉菌β内酰胺酶的产生情况。结果肺炎链球菌、流感嗜血杆菌和卡他莫拉菌的携带率分别为12.4%、4.6%、10.9%;肺炎链球菌血清分型中19F最多见,其余依次为14、19A和15、6B、23F、6A,且春季和秋冬季无明显差别;PCV7、PCV9、PCV10价疫苗覆盖率均为48.6%,PCV13覆盖率为61.0%,后者明显高于前者;此外,19A的耐药性高于多数血清型(包括19F),23F的耐药性强于其他血清型,6A的耐药性强于6B。不同城市间青霉素耐药肺炎链球菌、青霉素中介肺炎链球菌、青霉素敏感肺炎链球菌所占比例分别为11.6%～28.6%、19.6%～54.4%、32.0%～62.8%。流感嗜血杆菌和卡他莫拉菌对大部分抗菌药物敏感,22.7%和21.0%的卡他莫拉菌对红霉素和阿奇霉素耐药,济南的耐药率高达50.0%和44.8%。卡他莫拉菌β-内酰胺酶阳性率为85.0%～100.0%;未发现β-内酰胺酶阴性氨苄西林耐药的流感嗜血杆菌。结论 2岁以下健康婴幼儿鼻咽部携带肺炎链球菌中以19F最多见,19A耐药性强于其他血清型;肺炎链球菌、流感嗜血杆菌及卡他莫拉菌对常用抗生素的耐药性增加,应引起高度重视。     

2003-2004年广州地区儿童肺炎链球菌、流感嗜血杆菌抗生素敏感性调查

目的了解2003-2004年广州地区儿童呼吸道感染常见病原肺炎链球菌和流感嗜血杆菌对常用抗生素的敏感性,以便有效指导临床合理用药和预防.方法对2003-2004年在广州市儿童医院就诊的1565例上呼吸道感染儿童鼻咽分泌物进行培养,分离肺炎链球菌和流感嗜血杆菌;采用纸片扩散法及E-test方法对分离株进行常用抗生素敏感性检测.结果从1565例呼吸道感染儿童鼻咽部分离肺炎链菌球共172株,流感嗜血杆菌484株.172株肺炎链球菌对常用抗生素耐药株数（耐药率）分别为：青霉素55（32.0%）、阿莫西林/克拉维酸19（11.1%）、头孢曲松56（32.6%）、头孢呋辛31（18.1%）、头孢克洛68（39.5%）、红霉素142（82.6%）、四环素135（78.5%）、氯霉素42（24.4%）、复方磺胺甲基异噁唑150（87.2%）、克林霉素119（69.2%）、氧氟沙星5（3.1%）;肺炎链球菌的青霉素不敏感株对β-内酰胺类、红霉素、复方磺胺甲基异噁唑耐药率明显高于青霉素敏感株,且多重耐药率在90%以上.484株流感嗜血杆菌中,143株β-内酰胺酶阳性,产酶率为29.5%,484株流感嗜血杆菌的耐药株数（耐药率）分别为：氨苄西林194（40.1%）,阿莫西林/克拉维酸16（3.4%）、头孢曲松20（4.1%）、头孢呋辛9（1.9%）、头孢克洛27（5.6%）、复方磺胺甲基异噁唑272（56.2%）、四环素252（52.1%）、氯霉素84（17.4%）、阿奇霉素10（2.1%）、氧氟沙星3（0.6%）.结论广州地区儿童呼吸道肺炎链球菌和流感嗜血杆菌耐药形势严峻,与该地区前3年资料比较,肺炎链球菌对青霉素敏感性有所增加,但对头孢曲松耐药性增加,青霉素不敏感株的多重耐药率较高,以红霉素、四环素、复方磺胺甲基异噁唑多重耐药为主要特点.流感嗜血杆菌的产酶率上升,导致菌株对氨苄西林耐药性明显增高,对头孢二、三代抗生素、阿莫西林/克拉维酸、阿奇霉素有较高的敏感性.     

2000-2002年三家儿童医院分离的肺炎链球菌血清型分布及其对β内酰胺类抗生素敏感性的变化

目的 了解当前我国儿童人群中肺炎链球菌血清型分布,及不同血清型菌株对B内酰胺类抗生素的敏感性变化,评估疫苗在预防肺炎链球菌感染及控制其耐药性流行中的价值。方法 以2000-2002年于北京、上海和广州三家儿童医院门诊分离的625株肺炎链球菌为研究对象,应用简易棋盘式肺炎链球菌分型系统检测血清型,分析肺炎链球菌7价结合疫苗（4、6B、9V、14、18C、19F和23F）覆盖率;采用E—test最小抑菌浓度（MIC）法检测分离菌株对5种B内酰胺类抗生素的敏感性。结果最常见的血清型／群为19群,共121株（19．4％）,其次是23群（15．4％）、6群（13．3％）、14型（6．6％）和15群（4．3％）。140株（22．4％）不能分型,还有117株（18．7％）属于其他28种少见的血清型／群。肺炎链球菌7价结合疫苗覆盖约360株,占57．6％;其中,血清型／群4、9和18分别有1、6和12株,共计占3．0％。常见血清型／群中,19群和23群与青霉素不敏感肺炎链球菌（PNSP）明显有关,其他血清型／群与PNSP无明显相关。结论 常见的血清型为19群、23群、6群、14型和15群,19群和23群与PNSP明显相关。肺炎链球菌7价结合疫苗可覆盖多数分离株。     

北京上海广州深圳4家儿童医院肺炎住院患儿肺炎链球菌分离株的血清型分布

目的了解目前从中国住院治疗肺炎患儿分离到的肺炎链球菌的血清型分布，及几种蛋白多糖结合疫苗的覆盖率，评估应用蛋白多糖结合疫苗预防肺炎链球菌感染的价值。方法选择2006年2月16日至2007年2月16日在首都医科大学附属北京儿童医院、复旦大学附属儿科医院、广州市儿童医院和深圳市儿童医院呼吸科住院治疗的肺炎患儿为研究对象，采用一次性吸痰管收集全部病例的呼吸道分泌物标本分离肺炎链球菌，部分患儿进行脑脊液、血液和胸腔积液中肺炎链球菌的分离。采用荚膜肿胀实验进行血清型分析。对4家儿童医院肺炎链球菌分离率和血清型进行分析，率的比较采用χ2检验或Fisher精确概率法。结果 研究期间共纳入2 865例肺炎患儿，2 865例呼吸道吸取物标本中分离到肺炎链球菌279株，其中有2株不同血清型菌株分离自同一病例，分离阳性率为9.7％（278/2 865）。3/8例胸腔积液中分离到肺炎链球菌，其中2例同时从呼吸道分泌物分离到肺炎链球菌，取其一进行血清分型，另1株从胸腔积液中分离的肺炎链球菌复苏失败，未进行血清分型。脑脊液和血液标本中未分离到肺炎链球菌。共有279株肺炎链球菌进行了血清型分析，以19F型最常见（60.6％，169/279），其次为19A（9.7％，27/279）、23F（9.3％，26/279）和6B（5.4％，15/279），上述4种血清型占全部菌株的84.9％（237/279）。肺炎链球菌7价结合疫苗（PCV7）覆盖率为81.0％，但在北京仅为46.0％，明显低于上海（80.0%）、广州(98.4%)和深圳（94.4%）。9价、10价和11价疫苗的覆盖率与PCV7相比并没有明显增加。13价疫苗的覆盖率（92.8％）较PCV7明显升高。结论4家儿童医院肺炎住院患儿分离的肺炎链球菌以19F、19A、23F和6B型常见。PCV7覆盖率为87％     

四地儿童肺炎链球菌、流感嗜血杆菌抗生素敏感性监测(2000～2001年)

目的 了解当前我国儿科呼吸道感染常见病原肺炎链球菌和流感嗜血杆菌对常用抗生素的敏感性，以便有效指导临床合理用药和预防。方法 连续两年对北京、上海、广州三家儿童医院和西安西京医院儿科（仅2001年）就诊的上呼吸道感染儿童鼻咽分泌物进行培养、分离肺炎链球菌和流感嗜血杆菌；采用纸片扩散法及E－test方法对分离株进行常用抗生素敏感性检测。结果 四地2年从呼吸道感染儿童鼻咽部分离肺炎链球菌共654株，流感嗜血杆菌669株。肺炎链球菌对青霉素不敏感（PRSP）率范围在14％－60％，2001年各地区发生率依次为上海55．0％、广州50．0％、西安45．0％、北京42．3％；与2000年相比，2001年部分地区如北京、上海青霉素中度敏感株明显增多。PRSP对β－内酰胺类、红霉素、复方磺胺甲基异恶唑耐药率明显高于青霉素敏感株（PSSP），且多重耐药率高达90％以上。北京、上海、西安地区分离株对阿莫西林／克拉维酸、头孢曲松仍具有很好的敏感性（96．6％－98．9％），而对头孢呋辛敏感性有不同程度下降，广州地区敏感率仅为59％，上海71％，而北京地区为92．3％，明显高于广州地区。2001年四地区分离株对头孢克洛总耐药率：广州地区耐药率最高（56％），上海、西安次之（15％、13％），北京最低（4．8％）。四地分离株对红霉素耐药率高达75％－96％，其中以高度耐药（≥256mg/L）为主，占80％－99％；2001年与北京地区分离株红霉素耐药率87．9％，高于上海（80％）、广州（78％）。肺炎链球菌四环素耐药情况与红霉素相近（60％－96％）；复方磺胺甲基异恶唑耐药也很突出（68％－88％）；而对氯霉素仍保持较低水平耐药（20％－30％）。各地区流感嗜血杆菌对氨苄青霉素、氯霉素耐药保持较低水平（5％－16％），多数地区对其他β－丙酰胺类抗生素有较好的敏感性（96％－100％），但2001年北京和广州对头孢克洛耐药已达12．7％和20％。对四环素、复方磺胺甲基异恶唑耐药率范围分别为11．3％－26．5％、37．5％－77．1％，各地区间耐药率略有差异。结论 四地区儿童上呼吸道感染肺炎链球菌和流感嗜血杆菌耐药形势严峻，PRSP已达中等水平，有逐年上升的趋势，并以红霉素、四环素、复方磺胺甲基异恶唑等多重耐药为主要特点。     

Prevalence of nasopharyngeal carriage of pneumococcus in preschool children attending day care in London.

OBJECTIVE: To estimate the prevalence of nasopharyngeal (NP) carriage of pneumococcus (Streptococcus pneumoniae) and describe the antibiotic resistance patterns and serotypes in young children attending group day care in London. DESIGN AND SUBJECTS: Cross-sectional survey of attendees at a sample of registered child day care centres (CDCCs) in a London borough. SETTING: Urban setting with a socially and culturally diverse population. METHODS AND OUTCOMES: 19 CDCCs (13% of total) participated between March and November 2003. A single NP swab was required from each child, and parents completed a questionnaire about their child's health and attendance at day care. WHO methodology for pneumococcal carriage studies was followed. RESULTS: 30% of parents consented. 234 swabs were collected from children aged 6 months to 5 years. 53% were boys and 81% were white. 120 children (51%, 95% CI 45% to 58%) carried pneumococci in their nasopharynx. None of the isolates were resistant to penicillin (upper CL 3%). 21 isolates were resistant to erythromycin (17.5%, 95% CI 11% to 25.5%). 68 isolates (57%) were serotypes included in the 7-valent conjugate vaccine. Non-white children had a lower prevalence of carriage (27% vs 58%). CONCLUSION: The prevalence of pneumococcal NP carriage was high. The penicillin resistance rate is lower than in many other countries and may reflect a decrease in community antibiotic prescribing in the UK. Monitoring circulating serotypes is important in the context of recent changes to the vaccination policy. Further study is required to explore the association with ethnicity and risk factors for antibiotic resistance.     

The Impact of the Heptavalent Pneumococcal Conjugate Vaccine on Risk Factors for Streptococcus pneumoniae Carriage in Children

BACKGROUND:: The aim of the study was to investigate whether the 7-valent pneumococcal conjugate vaccine (PCV7) alters common risk factors of nasopharyngeal carriage by Streptococcus pneumoniae in children. METHODS:: From July 2005 through December 2010, we performed a cross-sectional study investigating risk factors associated with pneumococcal carriage in children. Parents of participating children completed questionnaires including whether or not the children received PCV7 vaccination. RESULTS:: Among 9705 children, 20.2% of them received at least 1 dose of the PCV7 vaccine. Multivariate logistic regression models identified older age, having 1 sibling in a family, history of acute otitis media and household exposure to smoking as independent risk factors for pneumococcal carriage in the unvaccinated group, but not associated with pneumococcal carriage in the vaccinated group. The number of siblings ≥2 in a family, history of upper respiratory tract infection and child-care attendance were strong factors associated with pneumococcal carriage in children, regardless of vaccination. In vaccinated group, breast-feeding was associated with increased nonvaccine type pneumococcal carriage, mainly in children with upper respiratory tract infection. CONCLUSIONS:: PCV7 decreased the association between pneumococcal carriage and older age, 1 sibling in a family, history of acute otitis media and household exposure to smoking, but increased the association between pneumococcal carriage and breast-feeding.     

Nasopharyngeal carriage of <Emphasis Type="Italic">Streptococcus pneumoniae</Emphasis>

Objective To determine nasopharyngeal carriage rate and prevalent serogroups/ types (SGT) of S. pneumoniae in healthy children, assess their antimicrobial susceptibility and its implications over the heptavalent pneumococcal conjugate vaccine. Methods 200 healthy children aged between 3 months and 3 years attending Pediatric OPD at Sir Ganga Ram Hospital, New Delhi were studied. A nasopharyngeal swab was collected from each child which was processed to isolate Streptococcus pneumoniae. Serotyping was performed by the Quellung reaction. Antimicrobial susceptibility patterns were determined by disk diffusion and E test methods. Results S. pneumoniae carriage rate was 6.5%. Isolates belonged to serotypes 1, 6, 14 and 19, of which serotype 19 was the most common. None of the strains were totally resistant to penicillin though 2 (15.4%) were intermediately resistant. Overall, 84.6% of the isolates belonged to the strains covered by the heptavalent pneumococcal vaccine. Conclusion The heptavalent conjugate vaccine covers most isolated strains, but since the number of strains is very small, it is suggested that there is need for further studies in different regions to assess the usefulness of this vaccine.     

Nasopharyngeal colonization of Streptococcus pneumoniae in healthy children: percentage of carriers, serotypes distribution and antibiotic resistance

AIM: The nasopharyngeal carriage of Streptococcus pneumoniae is an important risk factor for pneumococcal diseases. Data regarding prevalence and serotype distribution of this pathogen are lacking in our population. METHODS: Experimental design: longitudinal observational cohort study. Setting: healthy children aged 1-7 years attending day-care centers and schools of a district of a Southern Italy city. Measures: the nasopharyngeal colonization rate of Streptococcus pneumoniae as well as its antibiotic susceptibility was determined. RESULTS: Of 317 nasopharyngeal cultures obtained, 18.29% of the cultures were positive for Streptococcus pneumoniae; 60.34% of the isolates were serotypes 19A, 19F, 14, 6B, or 23F; 8.62% of the strains were intermediately resistant to penicillin. Erythromycin-resistance was observed in 65.51% of the micro-organisms isolated and particularly serotypes 19, 14, and 6 were more erythromycin-resistant than organisms of other serotypes. Co-trimoxazole resistance was detected in 17.24% of the strains. All the strains resulted uniformly susceptible to cefotaxime and ceftriaxone. CONCLUSION: The high rate of nasopharyngeal carriage of Streptococcus pneumoniae, along with the resistance to antibiotics widely used in the community, suggests the importance of an epidemiological surveillance as well as the application of new vaccine strategies.     

Nasopharyngeal carriage of Streptococcus pneumoniae in healthy Turkish children after the addition of PCV7 to the national vaccine schedule

The aim of this study was to determine serotype distribution and investigate antimicrobial resistance patterns of Streptococcus pneumoniae in healthy Turkish children in the era of community-wide pneumococcal conjugate vaccine (PCV7). The study was conducted on 1,101 healthy children less than 18 years of age. Specimens were collected with nasopharyngeal swabs between April 2011 and June 2011. Penicillin and ceftriaxone susceptibilities were determined by E-test according to the 2008 Clinical Laboratory Standards Institute, and serotypes of the isolates were determined by Quellung reaction. The nasopharyngeal pneumococcal carriage rate was 21.9 % (241/1,101). Using the meningitis criteria of minimum inhibitory concentration values, 73 % of the isolates were resistant to penicillin and 47.7 % of them were resistant to ceftriaxone. Half of all pneumococcal isolates were serotyped as 19F (15.2 %), 6A (15.2 %), 23F (10.3 %), and 6B (9.3 %) and surprisingly, no serotype 19A was isolated. Serotype coverage rates of PCV7 and non-PCV7 were 46.2 and 53.8 %, respectively. The most common penicillin- and ceftriaxone-resistant serotypes were 6A, 6B, 14, 19F, and 23F. Penicillin- and ceftriaxone-resistant isolates were more prevalent in serotypes covered by PCV7 than the non-PCV7 serotypes. Conclusion: After the community-wide PCV7 vaccination, more non-PCV7 serotypes were isolated from the carriers compared to the time before PCV7 was used especially the serotype 6A, and the antimicrobial resistance of pneumococci was significantly increased.     

Pneumococcal nasopharyngeal carriage and patterns of penicillin resistance in young children in Fiji

BACKGROUND: Little is known about nasopharyngeal carriage and the patterns of antibiotic resistance of pneumococci in Pacific nations. We set out to document pneumococcal nasopharyngeal carriage and associated risk factors, antimicrobial resistance and serotypes in healthy children in Fiji. METHODS: A cross-sectional survey of healthy children aged 3-13 months was conducted. Nasopharyngeal (NP) swabs were collected from each child and processed according to standard methods. Antimicrobial resistance was determined by disk diffusion and confirmed by E-testing. Serotyping was performed by the Quellung reaction. RESULTS: Of 440 consecutive NP swabs taken, 195 were S. pneumoniae-positive (carriage rate 44.3%). Higher rates were found in the indigenous Fijian population. Penicillin non-susceptibility was found in 11.4% of isolates, with one isolate demonstrating high-level resistance. Cotrimoxazole resistance was common (20.3%) and no isolates were chloramphenicol-resistant. Multi-drug resistance was uncommon. The commonest serotypes were 6A (13.2%), 23F (8.3%), 19F (7.4%) and 6B (6.2%). Thirty per cent were included in the 7-valent pneumococcal conjugate vaccine (PCV), 54.3% if cross-reacting strains were included. Being indigenous Fijian or having symptoms of acute respiratory infection were independent risk factors for carriage. CONCLUSIONS: Pneumococcal NP carriage is common in Fijian children. Penicillin resistance has been documented for the first time in Fiji and, as a result, first-line treatment for meningitis has been altered. Being indigenous Fijian is a risk factor for disease, although the reasons for this are unclear. A low proportion of carriage serotypes are covered by the existing 7-valent PCV.     

Antimicrobial resistance of Streptococcus pneumoniae isolated from healthy children in day-care centers: results of a multicenter study in Russia

BACKGROUND: It has been previously shown that study of susceptibility of nasopharyngeal isolates in healthy carriers can predict resistance in clinical isolates. The purpose of this multicenter study was to determine the carriage rate of Streptococcus pneumoniae in healthy children attending day-care centers in Moscow, Smolensk and Yartsevo, Russia, and in vitro activity of penicillin G, amoxicillin/clavulanate, cefaclor, erythromycin, roxithromycin, clarithromycin and trimethoprim-sulfamethoxazole (TMP-SMX) against representative isolates. METHODS: Included in this study were 305 pneumococcal isolates from 733 children attending 9 day-care centers in Moscow, Smolensk and Yartsevo. All children enrolled in this study were <7 years of age. MICs of selected antimicrobials were determined by Etest. Serotyping of selected pneumococcal isolates was done with pool and type antisera. RESULTS: The carriage rate of S. pneumoniae in the 3 centers varied from 44.9% to 66.0% (mean, 55.9%). Susceptibility testing was performed with 305 (74.4%) of 410 isolates. Only 23 (7.5%) of 305 pneumococcal isolates were penicillin-intermediate (range, 2.8 to 12.8%) with no penicillin-resistant strains. All tested pneumococci were susceptible to amoxicillin/clavulanate. Macrolides possessed comparable activity against S. pneumoniae, at 4.6% resistant strains for both erythromycin (range, 1.1 to 17.1%) and clarithromycin (range, 1.7 to 17.1%). The highest level of resistance was observed with TMP-SMX, 53.4% (range, 43.8 to 70.9%). Of 23 strains 20 (87.0%) with intermediate resistance to penicillin were serotyped. The most prevalent serotype was 14 (5 isolates), followed by serogroups 19 (4) and 23 (4). CONCLUSIONS: Resistance to penicillin, other beta-lactams and macrolides does not seem to be a problem for Russia now. The high level of resistance to TMP-SMX considerably restricts its usage for the treatment of pneumococcal infections.     

Nasopharyngeal carriage of penicillin-resistant Streptococcus pneumoniae in healthy children

Streptococcus pneumoniae carriage is a risk factor for the development of respiratory system infections and the spread of penicillin-resistant strains. The aim of this study was to investigate nasopharyngeal carriage of S. pneumoniae in healthy children and resistance to penicillin and other antimicrobials and to assess related risk factors. Nasopharyngeal specimens collected from healthy children less than six years of age, visiting a Mother and Child Health Center for health control, were investigated microbiologically between February-March 2004. Carriage rate was 37.2% (n=112/301); 33.9% intermediate and 5.4% high penicillin resistance were detected. According to multivariate analysis, carriage rate was inversely related to number of rooms (OR:0.574) and child age (OR:0.978), while penicillin resistance was correlated well with antibiotic use in the last two months (OR:2.193). Decreased sensitivity plus resistance to other antimicrobials were: trimethoprim-sulfamethoxazole (TMP-SMX) 45.6%; erythromycin 16.1%, tetracycline 16.1%; clindamycin 9.8%, and ofloxacin 3.6% in pneumococcal isolates, which increased significantly (p<0.05) to 72.7%, 31.8%, 27.3%, 20.5%, and 6.8%, respectively, in penicillin non-sensitive S. pneumoniae (PNSSP) except for ofloxacin. Overall multidrug resistance was 17.9%, while PNSSP exhibited a resistance rate of 38.6%. In conclusion, S. pneumoniae carriage rates determined in healthy children were high and PNSSP strains also showed increased resistance to other antimicrobials.