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。     

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。     

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.     

上呼吸道感染儿童鼻咽部携带肺炎链球菌状况及血清型和耐药性研究

目的 了解上呼吸道感染儿童鼻咽部携带肺炎链球菌状况,以及分离株的耐药性和血清型分布。方法 2013 年3 月至2014 年2 月采集在北京儿童医院门诊就诊的上呼吸道感染儿童鼻咽拭子进行细菌培养和鉴定,采用Etest 方法检测抗生素敏感性,荚膜肿胀试验检测血清型。结果 共采集到2 941 例1 月龄至16 岁患儿的鼻咽拭子,分离出肺炎链球菌699 株,携带率为23.8%。随机选取100 株菌检测了抗生素敏感性和血清型。分离株对静脉青霉素敏感率达98.0%,口服青霉素敏感率仅为33.0%,头孢克洛耐药率为54.0%,头孢曲松和亚胺培南中介率也分别达到18.0% 和38.0%。红霉素和阿奇霉素不敏感率均为97.0%。多重耐药率为86.0%。常见血清型为6A（12.0%）、19F（12.0%）、6B（10.0%）、23F（9.0%）和14 型（8.0%）,7、10 和13 价结合疫苗覆盖率分别为41.0%、42.0% 和59.0%。结论 门诊上呼吸道感染儿童中,鼻咽部肺炎链球菌携带率约为25%,抗生素耐药分离株常见,13 价结合疫苗覆盖率接近60.0%。     

住院患儿细菌培养标本分离肺炎链球菌特征分析

目的 分析住院患儿细菌培养标本中所检出肺炎链球菌的分布、血清型及耐药性特征。方法　收集2013年3月至2014年2月在首都医科大学附属北京儿童医院呼吸、感染及重症监护病房住院的195例患儿送检的细菌培养标本,对其进行肺炎链球菌常规检测、血清分型和药物敏感性试验。按照2013年临床实验室标准化委员会（CLSI）推荐的抗菌药物敏感性试验标准进行结果判断。应用WHONET 5.6软件对药敏结果进行耐药性分析。结果　195例患儿分离到肺炎链球菌,其中婴幼儿占66.1%。195例中共检出20种血清型,其中19F最多,占32.3%,其次19A,占20.5%。肺炎链球菌对红霉素和克林霉素最不敏感（敏感率＜5%）,对青霉素不敏感率为46.7%。与对青霉素敏感的肺炎链球菌进行抗菌药物耐药性比较后显示,青霉素不敏感肺炎链球菌对头孢噻肟、头孢吡肟、美罗培南和复方新诺明不敏感率均高于敏感菌株,差异存在统计学意义（P＜0.05）。结论　在儿科,肺炎链球菌的检出、流行型别的确定以及耐药性检测均不容忽视,应进行疫苗预防接种和合理选择抗菌药物进行抗感染治疗。     

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。     

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％     

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。     

5岁以下健康儿童鼻咽部肺炎链球菌的流行病学研究

目的了解武汉地区儿童肺炎链球菌携带率、耐药性、耐药基因及血清型流行状况。方法采集鼻咽拭子,以琼脂稀释法测定肺炎链球菌对12种抗菌药物的最低抑菌浓度,聚合酶链式反应检测红霉素耐药基因,荚膜肿胀试验进行血清学分型。结果武汉地区儿童肺炎链球菌携带率为22．31％（135／605）。存活的133株细菌中,青霉素不敏感肺炎链球菌（PNSSP）发生率为45．9％（61／133）;头孢菌素第一代（头孢氨苄）、二代（头孢克洛）、三代（头孢克肟、头孢泊肟、头孢曲松）敏感率依次为6．0％、45．1％、54．9％、56．4％、88．7％;除1株环丙沙星低耐株外,未发现氟喹诺酮类耐药株。大环内酯类敏感率仅为14．3％～15．8％。在114株红霉素耐药株中,检出ermB基因76株（66．7％）,2株（1．8％）低耐株含有mefA基因,46株（40．4％）同时具有ermB和mefA基因。血清分型涉及17个血清群,主要分布在19、23、6、15和14血清群,7株细菌未能分群。PNSSP分布在19、23、6和未分型血清群。结论武汉地区肺炎链球菌耐药严重,红霉素耐药主要为核糖体修饰（ermB介导）引起。流行血清群以19、23、6为主。     

四家儿童医院住院肺炎病例肺炎链球菌分离株的耐药性监测

目的：了解从我国住院肺炎儿童分离的肺炎链球菌对抗菌药物的敏感性状况,为临床用药提供依据。方法：肺炎链球菌分离自2006年2月~2007年2月在北京、上海、广州和深圳4家儿童医院住院的肺炎患儿,采用E试验法检测菌株对8种抗生素的敏感性。结果：279株肺炎链球菌对青霉素的不敏感率为86.0％,耐药率达23.3％。在检测的β内酰胺类抗菌药物中,肺炎链球菌对阿莫西林还保持着很高的敏感率（92.1％）,对头孢呋辛和头孢曲松的敏感率分别为19.0％和75.3％。几乎全部菌株（99.6％）对红霉素耐药。万古霉素和氧氟沙星的敏感率分别为99.6％和97.8％。17.6％的分离株对亚胺培南不敏感,以中介株为主。不同地区分离的肺炎链球菌对红霉素、万古霉素和氧氟沙星的敏感状况没有明显不同,但对其他几种抗菌药物的敏感性状况存在差异。结论：从肺炎住院儿童分离的肺炎链球菌对阿莫西林、万古霉素和氧氟沙星敏感率高,对头孢曲松和亚胺培南比较敏感,对青霉素、头孢呋辛和红霉素普遍不敏感或耐药。     

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.     

Impact of conjugate vaccine on transmission of antimicrobial-resistant Streptococcus pneumoniae among Alaskan children

BACKGROUND: The impact of heptavalent pneumococcal conjugate vaccine (PCV7) on transmission of antimicrobial-resistant Streptococcus pneumoniae is an important concern for countries considering PCV7 introduction. METHODS: Every winter from 2000 to 2004, as PCV7 was routinely introduced, we obtained nasopharyngeal swabs for pneumococcal culture, serotyping, and susceptibility testing from 150 children aged 3-59 months at each of 3 Anchorage, Alaska clinics. We assessed risk factors for pneumococcal carriage, including vaccination status and antimicrobial use. RESULTS: Between 2000 and 2004, 2250 nasopharyngeal swabs from 2061 infants and children were collected. The proportion of children receiving > or = 1 PCV7 vaccination increased from 0 to 89%, whereas overall pneumococcal carriage remained stable (38% versus 41%, respectively). Among S. pneumoniae carriers, we observed declines in carriage of PCV7 serotypes (from 54% to 10%, P < 0.01) and trimethoprim-sulfamethoxazole nonsusceptible strains (44% to 16%, P < 0.01), but not in PCN-nonsusceptible strains (36% versus 37%). Among PCN-nonsusceptible types, the proportion of serotype 19A strains increased from 10% to 32% (P = 0.0002). Recent beta-lactam use was stable throughout the period (29% overall), whereas trimethoprim-sulfamethoxazole use declined from 6% to 2% (P = 0.02). CONCLUSIONS: PCV7 vaccination in the first 5 years did not affect overall pneumococcal carriage, but was associated with a shift in serotype distribution from PCV7 types to non-PCV7 types. With persistent pressure of some antimicrobials, reductions in carriage of antimicrobial nonsusceptible PCV7 types may be offset by increases in carriage of nonsusceptible non-PCV7 types.     

Impact of heptavalent pneumococcal conjugate vaccine on nasopharyngeal carriage of penicillin-resistant Streptococcus pneumoniae among day-care center attendees in central Greece

BACKGROUND: In Greece, the heptavalent pneumococcal conjugate vaccine (PCV7) became available in October 2004 and it was incorporated into the national immunization schedule in January 2006. METHODS: In February 2005, a yearly surveillance of the nasopharyngeal colonization with Streptococcus pneumoniae in children attending day-care centers in Central Greece began. RESULTS: Between February 2005 and May 2007, nasopharyngeal cultures were obtained from 1829 children aged 13-76 months (median age, 47 months). The proportion of attendees vaccinated with > or =1 doses of PCV7 increased from 13% (2005) to 33% (2006) and to 70% (2007); 98% had been immunized on toddler catch-up schedules. Among vaccinated carriers, the proportion of PCV7 serotypes decreased from 33% (2005) to 29% (2006) and to 8.6% (2007) (chi for trend, P < 0.001), the proportion of PCV7-related serotypes increased from 13% (2005) to 26% (2006) and to 28% (2007) (P = 0.16), whereas the proportion of non-PCV7 serotypes was 48% in 2005, 31% in 2006, and 55% in 2007 (P = 0.17). The proportion of PCV7 serotypes declined also among unvaccinated carriers. The carriage of serotype 19A did not increase. Among vaccinated carriers, the rate of highly penicillin-resistant isolates decreased from year 1 to year 3, respectively, 11%, 7.7%, and 0.6% (P = 0.001), whereas the proportion of penicillin-intermediate pneumococci was 13% in 2005, 23% in 2006, and 26% in 2007 (P = 0.22). CONCLUSIONS: In Central Greece, widespread PCV vaccination was followed by a significant reduction of carriage of highly penicillin-resistant pneumococci. The frequency of penicillin-intermediate isolates did not change significantly among vaccinated carriers.     

Streptococcus pneumoniae antibiotic resistance in Northern Territory children in day care

BACKGROUND: There is evidence that the rapid rise in Streptococcus pneumoniae (SP) antimicrobial resistance seen in other countries may have commenced in Australia. Streptococcus pneumoniae carriage and resistance levels are described for urban Northern Territory children in day care. METHODS: A prospective cohort study was conducted of 250 children in nine Darwin day care centres between 24 March and 15 September 1997. Each fortnight nasopharyngeal swabs were collected from children, and parents were interviewed about medications administered. RESULTS: Streptococcus pneumoniae was detected in 52% (1028/1974) of all nasopharyngeal swabs. Streptococcus pneumoniae was isolated from 92% (231/250) of children at some time. Penicillin resistance was found in 30% (312/1028) of isolates using a screening test. Of these, 256 (82%) had resistance confirmed by E-test. Two hundred and one (20% of all isolates) had intermediate penicillin resistance and 55 (5% of all isolates) had high level resistance. Ceftriaxone resistance was found in 19% of children's first isolates. Resistance to other antibiotics was also common: co-trimoxazole 45%, erythromycin 17%, tetracycline 17% and chloramphenicol 13%. A total of 17% (172/1028) of the isolates were multiresistant. The average fortnightly proportion of children given antibiotics was 16% (405/2476). CONCLUSION: Levels of intermediate and high level penicillin resistance in this day care population are consistent with previous data from the Northern Territory, and considerably higher than the rest of Australia. The national trend of increasing pencillin resistance is likely to continue.     

Seven valent pneumococcal conjugate vaccine immunization in two Boston communities: changes in serotypes and antimicrobial susceptibility among Streptococcus pneumoniae isolates

BACKGROUND: Seven valent pneumococcal conjugate vaccine (PCV7) was licensed and introduced in 2000 for universal administration of children younger than 2 years of age and for selective immunization of children 2-5 years of age. SPECIFIC AIMS: To identify changes in colonization and antimicrobial susceptibility among Streptococcus pneumoniae organisms after introduction of PCV7. METHODS: Infants and children ages 2-24 months were enrolled in surveillance study of nasopharyngeal carriage of S. pneumoniae. Nasopharyngeal cultures for S. pneumoniae were performed at all well child visits and illness visits of children with acute otitis media. S. pneumoniae organisms were serotyped, and antimicrobial susceptibilities to penicillin, amoxicillin, trimethoprim-sulfamethoxazole and azithromycin were performed. RESULTS: During the 3-year period (October 2000 through September 2003), nasopharyngeal colonization with vaccine serotypes declined from 22% to 2%, and nonvaccine serotypes increased from 7% to 16%. Rates of antibiotic resistance of S. pneumoniae isolates to penicillin, amoxicillin, azithromycin and trimethoprim-sulfamethoxazole were 29.3, 2.2, 26.5 and 28.1%, respectively. CONCLUSIONS: PCV7 immunization produces a marked decline in vaccine serotypes carried in the nasopharynx of young children, with a coincident rise in the prevalence of nonvaccine serotypes. Important shifts in antimicrobial susceptibility have not been observed to date.     

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.