52株侵袭性肺炎链球菌血清型分布及耐药性分析

目的了解本院临床分离的侵袭性肺炎链球菌的血清型分布及耐药情况,为临床用药提供参考。方法采用荚膜肿胀试验检测2009年1月-2013年5月临床分离的52株侵袭性肺炎链球菌的血清型,采用最小抑菌浓度(MIC)稀释法检测药物敏感性。结果 52株侵袭性肺炎链球菌共鉴定出15个血清型/群,常见的血清型有14(21.2%)、19A(15.4%)、6B(11.5%)、19F(9.6%)、23F(9.6%)、3(9.6%)、6A(5.8%),其中有1株用此方法无法确定血清型;所有的侵袭性肺炎链球菌对万古霉素和左氧氟沙星均敏感,红霉素、四环素、氯林可霉素的耐药率分别为96.2%、64.7%、89.5%。结论本院临床分离的侵袭性肺炎链球菌的血清型主要集中在14、19A、6B、19F、23F、3、6A,对红霉素、四环素、氯林可霉素等耐药情况较严重。     

侵袭性肺炎链球菌感染临床特征与耐药性分析

目的研究侵袭性肺炎链球菌感染的临床特征及耐药性,分析其流行趋势,为有效预防与控制侵袭性肺炎链球菌感染提供依据。方法回顾性调查医院2008年10月-2014年10月非重复分离的41株侵袭性肺炎链球菌感染患者临床资料及药敏试验数据,分析其流行特征及耐药性。结果侵袭性肺炎链球菌感染多发生于内科和儿科病区,以60岁成人和5岁儿童居多,感染季节多在冬春更替期或秋季,感染类型以血液感染为主;41例侵袭性肺炎链球菌感染患者科室分布以内科和儿科为主,分别占58.6%和39.0%;肺炎链球菌对红霉素、四环素和磺胺甲噁唑/甲氧苄啶的耐药率均60.0%,对青霉素G耐药率达31.7%,未发现耐喹诺酮类、利奈唑胺和万古霉素菌株。结论加强侵袭性肺炎链球菌感染患者的目标性监测,明确其耐药特征,有利于预防与控制侵袭性肺炎链球菌感染及流行。     

侵袭性肺炎链球菌感染患儿的临床特点及炎症因子水平的变化

目的分析侵袭性肺炎链球菌感染患儿的临床特点及对常用抗菌药物的耐药性,观察患者炎症因子水平的变化。方法选择医院2008年1月-2017年12月收治的侵袭性肺炎链球菌病患儿200例为研究组,并选择健康体检儿童200例作为对照组。收集侵袭性肺炎链球菌感染患儿临床资料,采用纸片扩散法联合E-test分析肺炎链球菌对常用抗菌药物的敏感性。观察患儿血清炎症因子水平变化情况。结果 200例侵袭性肺炎链球菌病患儿,年龄以5岁以内多见占89.5%,其中<2岁患儿为128例占64.00%;以社区获得性感染为主占87.50%,冬春季发病为主占74.50%,有基础疾病占25.00%,诊断为败血症占42.50%;患儿临床症状均表现为发热,肝脾肿大占32.00%,皮疹占11.50%;实验室检查白细胞升高占79.00%,治疗后,治愈患儿占72.00%,好转占23.00%,死亡占5.00%;侵袭性肺炎链球菌对红霉素、阿奇霉素、四环素、克林霉素、磺胺甲噁唑/甲氧苄啶耐药率较高,未出现万古霉素、利福平、利奈唑胺耐药菌株。血清高敏C-反应蛋白(hs-CRP)、肿瘤坏死因子(TNF-α)、白介素-4(IL-4)、白介素-6(IL-6)、降钙素原(PCT)水平均高于对照组(P<0.05)。结论侵袭性肺炎链球菌病患儿以5岁以下多见,有季节性,临床表现多种多样,败血症最常见,耐药问题严峻,血清hs-CRP、TNF-α、IL-4、IL-6、PCT水平升高。     

46例儿童侵袭性肺炎链球菌感染的临床特征和抗生素敏感性分析

目的探讨我院46例儿童侵袭性肺炎链球菌感染临床特征及抗生素敏感性,以指导临床合理应用抗生素。方法回顾性分析2014年6月-2017年6月我院收治的46例侵袭性肺炎链球菌感染患儿临床资料及其药敏实验结果,分析其发病临床特征及对抗生素敏感性情况。结果 (1)46例侵袭性肺炎链球菌病患儿男女比例为1.56:1,2岁以下患儿居多,占58.70%。感染类型:社区获得性占80.43%(37/46),发病以秋冬季为主,临床诊断脓毒血症28例、脑膜炎8例、胸膜炎6例、坏死性肺炎2例、化脓性中耳炎和骨髓炎各1例。有基础疾病者8例,其中白血病3例,先天性心脏病2例,缺铁性贫血1例,头颅外伤1例,肾病综合征1例。合并其他病原菌感染者5例,其中合并支原体感染4例,产酸克雷伯杆菌1例。治愈率76.09%(35/46),转归23.91%(11/46),无死亡病例。(2)46例患儿均有发热,以弛张热或者稽留热为主。脓毒血症肺炎患儿出现咳嗽、呼吸困难、咳痰、发绀及肺部啰音等症状。脑膜炎患儿表现为惊厥、头疼、呕吐、意识障碍、肌张力增高、颈强直、病理征阳性等。胸膜炎患儿表现为呼吸减弱、患侧胸廓饱满呈浊音、呼吸音消失或者降低等胸腔积液症状及体征。(3)46株侵袭性肺炎链球菌中,21株对青霉素耐药,耐药率为45.65%;4株对青霉素中介,中介率8.70%;20株对青霉素敏感,敏感率43.48%。对其他抗生素不敏感率依次为:红霉素97.83%、阿奇霉素95.65%、克林霉素89.13%、复方新诺明76.09%、四环素71.74%、头孢噻肟47.83%、头孢吡肟41.30%、阿莫西林30.43%。对利福平、左氧氟沙星、万古霉素无耐药。多重耐药菌株占93.48%(43/46),其中青霉素耐药菌株多重耐药占100.00%,红霉素、阿奇霉素、克林霉素、四环素多重耐药模式最为常见,占56.52%(26/46)。结论本地区儿童侵袭性肺炎链球菌感染以2岁以下居多,临床疾病主要以脓毒血症及脑膜炎最为常见,加强临床耐药性检测对于指导侵袭性肺炎链球菌病临床用药意义重大。     

儿童血培养分离肺炎链球菌的耐药性

目的分析某儿童医院临床送检血标本分离的侵袭性肺炎链球菌耐药特点,指导临床合理用药。方法回顾性分析该院2007年4月—2011年6月临床分离的63株侵袭性肺炎链球菌的药敏资料。结果 63株肺炎链球菌对青霉素的敏感率为22.22%,对红霉素和复方磺胺甲口恶唑的敏感率低,分别为8.93%和28.57%;对阿莫西林、头孢曲松和头孢噻肟的敏感率较高,分别为85.71%、80.96%、85.71%;未检出万古霉素或利奈唑胺不敏感菌株。结论侵袭性肺炎链球菌耐药率高,应做好对其的耐药性监测,以指导临床合理用药,积极有效地治疗侵袭性肺炎链球菌疾病。     

检测阴性设计病例对照研究评价23价肺炎球菌多糖疫苗的儿童保护效果

目的 采用检测阴性设计病例对照研究评价23价肺炎球菌多糖疫苗（23-valent pneumococcal polysaccharide vaccine, PPV23）对儿童肺炎球菌[即肺炎链球菌（Streptococcus pneumonia, Spn）]相关呼吸道感染疾病的保护效果。方法 选取2017年1月1日—2020年12月31日因急性呼吸道感染（acute respiratory illness, ARI）在苏州大学附属儿童医院住院治疗的2岁≤年龄<10岁的患儿为研究对象，前瞻性收集呼吸道感染患儿中分离的肺炎链球菌菌株，通过荚膜肿胀实验确定Spn菌株血清型。采用检测阴性设计病例对照研究，病例组为感染PPV23血清型肺炎球菌的患儿，对照组分别为非疫苗血清型（non-vaccine serotype,NVT）患儿（感染非PPV23血清型肺炎球菌患儿）（NVT对照组）和肺炎球菌阴性（Spn–）患儿（临床样本中未检出感染Spn的患儿）（Spn–对照组）。在苏州市疾病预防控制中心的疫苗接种登记数据库中查询患儿PPV23接种的相关信息。采用Logistic回归模型估计PPV23接种...     

儿童大叶性肺炎570例临床分析

目的:分析儿童大叶性肺炎的临床特点、病原学变迁及治疗转归。方法:对2005年1月～2009年6月于吉林大学第一医院接受诊治的570例儿童大叶性肺炎患儿的临床症状、体征,病原学特点及治疗转归进行回顾性分析。结果:570例患儿中发热456例,咳嗽535例,胸痛39例,各型皮疹36例;肺炎支原体抗体阳性377例,金黄色葡萄球菌感染66例,白甲丝酵母菌感染36例,肺炎链球菌感染35例,肺炎克雷白杆菌及溶血性链球菌感染各32例,合并病毒感染119例;合并肺内并发症216例,肺外损伤以循环及消化系统为主;经系统治疗后,162例治愈,394例好转,14例死亡。结论:近年来,由肺炎链球菌感染引起的大叶性肺炎逐渐减少,而由支原体、病毒及其它细菌感染引起的大叶性肺炎逐渐增多。对于高热持续不退,刺激性干咳时间长,肺部体征不明显的大叶性肺炎患儿,应加强支原体抗体检测,必要时可早期应用大环内酯类药物;对于感染较重的大叶性肺炎的患儿,应及时行体液培养及药敏鉴定,明确病原、针对用药,抗生素应足量、足疗程联合应用。     

头孢类、青霉素或联合用药对新生儿感染性肺炎患儿临床治愈率、治愈时间及肠道微生态的影响

目的分析头孢类、青霉素或联合用药对新生儿感染性肺炎患儿临床治愈率、治愈时间及肠道微生态的影响。方法随机选取我院2015年6月至2017年6月195例无并发症新生儿感染性肺炎患儿作为研究对象,按照治疗时间的先后分成头孢组、青霉素组以及联合用药组各65例,比较三组患儿的临床治愈率、治愈时间。同时选取70例健康新生儿作为空白对照组,比较四组新生儿的肠道微生态。结果三组患儿的临床治愈率、治愈时间均提示差异无统计学意义(P0.05);三组患儿的消化链球菌、肠球菌以及肠杆菌数量显著高于对照组(P0.05);三组患儿的双歧杆菌数量显著低于对照组(P0.05);四组类杆菌数量提示差异无统计学意义(P0.05)。结论新生儿感染性肺炎患儿临床上多采用头孢类、青霉素联合用药,但是其会打破新生儿的肠道微生态,导致患儿机体处于失衡状态,故临床上对于新生儿应该谨慎使用联合用药。     

社区获得性肺炎流行特征及病原学分布

目的 探讨太原地区社区获得性肺炎流行特征及病原学分布,为制定防治策略和措施提供科学依据.方法 收集太原地区2005年12月～2006年12月社区获得性肺炎患者243例,采用现场调查和实验室检测方法检测病原体种类,包括肺炎链球菌等数10种病原菌、肺炎支原体IgM抗体、肺炎衣原体IgG抗体以及军团菌-DNA等.结果 太原地区社区获得性肺炎患者以老年人、军人和农民工为主;冬春季高发.病原体主要为肺炎链球菌、肺炎支原体和军团菌.肺炎链球菌对青霉索、大环内酯类抗生素高度耐药,对三代头孢、糖肽类抗生素高度敏感.结论 肺炎链球菌是社区获得性肺炎主要致病菌;非典型病原体尤其是肺炎支原体感染在太原地区社区获得性肺炎中占据重要地位;细菌合并非典型病原体的混合感染不容忽视.     

一所大型教学医院临床分离肺炎链球菌耐药性分析

目的了解一所大型教学医院临床分离的肺炎链球菌临床分布及耐药情况,为临床合理使用抗菌药物,预防和控制感染提供依据。方法收集中南大学湘雅医院2010年11月-2012年11月临床标本分离的肺炎链球菌192株,均经全自动细菌鉴定仪鉴定。采用K B法检测其对常用14种抗菌药物的敏感性,琼脂稀释法检测青霉素的最低抑菌浓度(MIC)。结果肺炎链球菌主要分离自儿科（36.98%）,标本主要为痰液（64.07%）;患者年龄呈双峰分布,以＜5岁和＞50岁的感染者较多。肺炎链球菌对红霉素、氯霉素、四环素、克林霉素耐药率均＞80%。192株肺炎链球菌青霉素MIC范围为0.015～≥32.0 μg/mL,其中MIC50为2.0 μg/mL,MIC90为16.0 μg/mL。非侵袭性肺炎链球菌耐药性高于侵袭性肺炎链球菌。结论该院肺炎链球菌耐药情况较为严重,在临床上对肺炎链球菌的治疗应重视青霉素耐药菌株的出现。     

Non-linear relationships between children age and pneumococcal vaccine coverage: Important implications for vaccine prevention strategies

BackgroundStreptococcus pneumoniae (S. pneumoniae) is an important pathogen causing both invasive and non-invasive infections in children, with significant morbidity and mortality worldwide. This study aimed to determine the potential relationships between age and vaccine coverage and between multiple phenotype-genotype characteristics of S. pneumoniae isolated from children.MethodsAll S. pneumoniae isolates were tested for antimicrobial susceptibility, virulence genes, serotypes, and sequence types. The restricted cubic spline models were used to reveal potential relationships between children age and pneumococcal vaccine coverage.ResultsFor capsular-based vaccines, we observed a high coverage rate of 13-valent pneumococcal conjugate vaccine (PCV13, 85.8%) and a significantly non-linear relationship between children age and vaccine coverage (including PCV7, PCV10, and PCV13), with marked fluctuations in children aged < 2 years. For protein-based and pilus-based vaccine candidates, we demonstrated dynamic non-linear relationships between age and vaccine coverage, maintaining a stable and high coverage rate of ply and lytA for all age groups. Moreover, there were significantly high-dimensional corresponding relationships among multiple phenotype-genotype characteristics of S. pneumoniae isolates (such as ST271 associated with serotype 19F, PI-2, and extensively drug-resistance).ConclusionsOur findings suggest that the age for high PCV coverage being children aged ≥ 2 years and also provide important evidence for supporting ply and lytA as priority candidate targets for the development of new-generation protein vaccines.     

In-depth analysis of pneumococcal serotypes in Belgian children (2015–2018): Diversity,invasive disease potential,and antimicrobial susceptibility in carriage and disease

BackgroundChanges in serotype distribution have been described after the switch from the 13-valent pneumococcal conjugate vaccine (PCV13) to the 10-valent pneumococcal conjugate vaccine (PCV10) in Belgium.AimTo describe serotype’s invasive disease potential and the detailed evolution of serotype distribution and antimicrobial susceptibility of pneumococcal isolates (carriage and IPD) in children up to 30 months of age over a period during and after the vaccine switch (2015–2018).MethodsS. pneumoniae strains isolated from the nasopharynx of healthy children attending day-care centres (DCCs) and strains from normally sterile sites of children with IPD were serotyped (Quellung-reaction) and antimicrobial susceptibility testing was performed. Invasive disease potential was defined as the serotype-specific odds ratio (OR).ResultsThe highly invasive (OR > 1) serotypes 12F, 1, 3, 24A/B/F, 33F, 19A, and 9N were not frequently carried (<7.5% of carriage strains). Different serotypes dominated in carriage (23B, 23A, 11A, 15B) versus IPD (12F, 19A, 10A, 33F). PCV13 vaccine serotypes increased in carriage (5.4% (25/463) in period 1 vs 10.3% (69/668) in period 3) and in IPD (7.3% (8/110 in period 1 vs 23.9% (34/142) in period 3) due to an increase (p < 0.01) in serotype 19A. The penicillin non-susceptibility of 19A was lower (p = 0.02) in carriage (6.8%) than in IPD (23.5%). Erythromycin and tetracycline non-susceptibility were more frequent (p < 0.01) in IPD (26.0%; 23.0%) compared to carriage strains (18.2%; 14.5%) and penicillin non-susceptibility increased over the three year study period (carriage: 13.4%, 19.8%, 18.5%, p = 0.05; IPD: 11.8%, 15.0%, 20.4%, p = 0.02).ConclusionOnly some of the serotypes with high invasive disease potential (serotype 1, 3, 19A) in Belgium are included in PCV10 and/or PCV13. This reinforces the need for continuous monitoring, both in healthy children as in children with IPD, to better understand the dynamics of pneumococcal disease, to optimise the composition and implementation of PCVs.     

Nasopharyngeal carriage of Streptococcus pneumoniae in healthy children aged less than five years

PurposeIn Turkey, pneumococcal conjugate vaccine (PCV) was introduced to the national immunization program as PCV7 in 2008, and was replaced with PCV13 in 2011. The aim of the study was to demonstrate the pneumococcal carriage rate and the serotype distribution in healthy children under 5 years in Turkey who were vaccinated with PCV13.MethodsWe conducted a cross-sectional study including the collection of questionnaire data and nasopharyngeal (NP) specimens among children aged <5 years from five centers from March 2019 to March 2020. Pneumococcal isolates were identified using optochin sensitivity and bile solubility. Serotyping was performed using a latex agglutination kit and Quellung reaction.ResultsNP swab samples were collected from 580 healthy children. The observed overall carriage rate was 17.8%. None of the hypothesised predictors of S. pneumoniae carriage, except maternal education level was statistically significant (p = 0.017). High maternal education level appeared to decrease the risk (lower vs. higher maternal education OR: 1.992 [95% CI; 1.089–3.643], p = 0.025). The overall NP S. pneumoniae carriage prevalence for the PCV13-vaccinated children was 17.8% (103/580). The most common serotypes detected were serotype 15B (n = 10, 9.7%), serotype 23F (n = 9, 8.7%), serotype 23A (n = 9, 8.7%), serotype 11A (n = 7, 6.7%), serotype 19F (n = 5, 4.8%) and serotype 15F (n = 5, 4.8%). Of the isolates, 28 (27.2%) were in PCV13 vaccine strains (VSs), and 75 (72.8%) strains were non-VS. The serotype coverage rate was 27.2% for PCV13.ConclusionThe overall S. pneumoniae carriage rate was higher than in earlier studies from Turkey. Post-vaccine era studies from around the world have reported a decrease in VS serotypes and a ‘serotype replacement’ to non-VS serotypes, as we determined in our study.     

The changing phenotypes and genotypes of invasive pneumococcal isolates from children in Shenzhen during 2013–2017

BackgroundThe phenotypes and genotypes of Streptococcus pneumoniae isolated from invasive pneumococcal diseases (IPDs) were changing all the time. To monitor these changes of phenotypes and genotypes of S. pneumoniae isolates from children, we examined antibiotic susceptibility, serotype distribution and sequence types (STs) of S. pneumoniae, which were isolated before the 13-valent pneumococcal conjugate vaccine (PCV13) introduced into China.MethodsStrains were isolated from children less than 14 years old between January 2013 and May 2017 from Shenzhen Children’s Hospital. Serotypes, antibiotic resistance, and genotypes of these isolates were determined using capsular swelling, E-test, and multi-locus sequence typing, respectively.ResultsA total of 94 S. pneumoniae strains were isolated, which belonged to 15 serotypes. The five most prevalent serotypes were 19F (25.5%), 19A (19%), 14 (17%), 23F (7.5%), and 6B (9.6%). We found 42 STs for these isolates. The most abundant STs were ST271 (24.4%), ST876 (17%), and ST320 (10.6%), mainly related to 19F, 14, and 19A, respectively. The potential coverage of PCV13 was 87.2%. Among non-meningitis isolates, the resistance rates to penicillin and ceftriaxone were 0% and 2%. However, the meningitis isolates showed high resistance to penicillin (80%) and ceftriaxone (20%). Most of these isolates (95.7%) were resistant to erythromycin, and 66 (70.2%) strains carried the ermB gene and 24 (25.5%) strains carried both the ermB and mefA/E genes. Serotype 19A showed the highest mean minimum inhibitory concentration (MIC) for penicillin (MIC = 1.486) than the other serotypes, but no significant difference in penicillin MIC among the three main STs (ST271, ST320, and ST876).ConclusionsThe phenotypes and genotypes of invasive pneumococcal isolates from Shenzhen Children’s Hospital have changed with the passage of time. Compared with PCV7, PCV13 can more effectively protect Chinese children from IPDs. To some extent, these changes are possibly related to the usage of antibiotics and vaccines.     

Phenotype,genotype, and serotype distribution of macrolide resistant invasive and non-invasive Streptococcus pneumoniae strains,in Sousse,Tunisia

ObjectiveWe determined the macrolide resistance phenotypes and genotypes in Streptococcus pneumoniae isolates in Sousse and assessed the serotype distribution.MethodsWe included S. pneumoniae strains isolated at our laboratory (2010–2013). The antimicrobial susceptibility was tested according to CA-SFM specifications. Serotyping was performed by agglutination of latex particles, to identify a subset of serotypes included in pneumococcal conjugate vaccines. The presence of macrolide resistance genes (ermB, mefA, mel) was detected by PCR.ResultsA total of 52.8% of 140 S. pneumoniae isolates were macrolide-resistant: MLSB (89.2%) and M (10.8%). The MLSB phenotypes were genotypically confirmed by ermB gene presence. 62% had decreased susceptibility to penicillin. The serotypes were: 14, 1, 23F, and 19A. Serotype coverage by PCV7, PCV10 and PCV13 was 44.2%, 73.6%, and 75.6% respectively.Conclusion50% of S. pneumoniae isolates were macrolide resistant. The MLSB phenotype encoded by the ermB gene was the most frequent. Serotype coverage seems inadequate.     

Serotype distribution of Streptococcus pneumoniae isolated from children hospitalized in Beijing children’s hospital (2013–2019)

BackgroundStreptococcus pneumoniae can cause many infectious diseases among children, and relevant vaccines have not been scheduled into the National Immunization Program in China. The serotype distribution of Streptococcus pneumoniae is essential information used to evaluate the value of pneumococcal vaccines and formulate immunization strategies.MethodsStreptococcus pneumoniae isolates, identified as the disease pathogens, were collected from children hospitalized in Beijing Children’s Hospital from 2013 to 2019. The serotype was detected by the Quellung reaction.ResultsA total of 903 isolates of Streptococcus pneumoniae were collected, among which 809 were from non-invasive infections and 94 were from invasive infections. The non-invasive isolates were mainly isolated from respiratory secretions (49.4%) and bronchoalveolar lavage fluid (38.9%), while invasive isolates were from venous blood (5.4%), cerebrospinal fluid (2.8%) and pleural effusion (2.8%). The leading serotypes were 19F (36.0%), 19A (13.6%), 23F (9.4%), 14 (8.9%), 6A (6.9%), and 6B (5.3%). The overall coverage rates of 10-, 13-, 15-, 20-valent pneumococcal conjugate vaccines (PCV10, PCV13, PCV15, PCV20) and 23-valent pneumococcal polysaccharide vaccine (PPV23) as well as Pneumosil (a 10-valent pneumococcal conjugate vaccine) were 61.6%, 83.2%, 83.4%, 88.0%, 82.4% and 81.6%, respectively. The coverage rates of PCV13, PCV15 and PPV23 in isolates from invasive infections were significantly higher than those from non-invasive infections. The coverage rates of Pneumosil, either on the whole or among different age groups or different infections, were significantly higher than those of PCV10.ConclusionsSerotypes 19F, 19A, 23F, 14, 6A and 6B were the most common types among the isolates. As for pneumococcal vaccines available now, the coverage rate of PCV13 was high, especially in isolates from invasive infections. The promotion of PCV13 or further high valent vaccines might be of greater benefit in preventing pneumococcal infections than other pneumococcal vaccines in children.     

Serotype Changes and Drug Resistance in Invasive Pneumococcal Diseases in Adults after Vaccinations in Children,Japan, 2010–2013

After 7-valent pneumococcal conjugate vaccine (PCV) for children was introduced in Japan in November 2010, we examined changes in Streptococcus pneumoniae serotypes and in genetic antimicrobial drug resistance of isolates from adults with invasive pneumococcal diseases. During April 2010–March 2013, a total of 715 isolates were collected from adults with invasive pneumococcal diseases. Seven-valent PCV serotypes in adults decreased from 43.3% to 23.8%, most noticeably for serotype 6B. Concomitantly, 23-valent pneumococcal polysaccharide vaccine (PPSV23) serotypes decreased from 82.2% to 72.2%; non-PPSV23 serotypes increased from 13.8% to 25.1%. Parallel with serotype changes, genotypic penicillin-resistant S. pneumoniae decreased from 32.4% to 21.1%, and 6 non-PPSV23 serotypes emerged (6D, 15A, 15C, 16F, 23A, and 35B). Respective vaccine coverage rates for 13-valent PCV and PPSV23 differed by disease: 73.9% and 84.3% for patients with pneumonia, 56.4% and 69.2% for patients with bacteremia and sepsis, and 45.7% and 69.3% for patients with meningitis.     

The impact of PCV7/13 on the distribution of carried pneumococcal serotypes and on pilus prevalence; 14 years of repeated cross-sectional surveillance

BackgroundS. pneumoniae carriage by children is a major source of pneumococcal transmission, and the initial step prior to infection. Pilus type 1, reported in ~30% of pneumococcal strains in the pre-vaccine era, contributes to pneumococcal colonization and virulence. In this study, we report the impact of the pneumococcal conjugate vaccine (PCV), PCV7/PCV13 sequential implementation on serotype distribution, and on the prevalence of piliated strains among carried pneumococci during the pre- and post-vaccine eras.MethodsDuring 2002-2016, 12 repeated cross-sectional surveillances of nasopharyngeal S. pneumoniae carriage were conducted among 8,473 children <5.5 years old visiting primary care physicians in Central Israel. Seven biannual surveillances in the pre-PCV period, 2 surveillances after PCV7 was licensed but before implementation in the National Immunization Plan, and 3 additional surveillances in the post-PCV period. S. pneumoniae serotype distribution and prevalence of piliated strains were assessed.ResultsCarriage of S. pneumoniae was relatively stable (45.4%). The prevalence of serotypes included in PCV13 was 65.7%, in the pre-vaccine period and the pilus was present in 26.4% of isolates. The distribution of serotypes and the pilus prevalence in the pre-PCV period was relatively stable except for a decrease in prevalence of piliated 19F, observed following the first study year. Following PCV7/PCV13 implementation, vaccine type 13 (VT13) strains were nearly eliminated to 3.3% by 2016. Piliated strains, which were primarily of VT13 serotypes, initially followed a similar trend and were nearly eliminated by 2014 (1.7%). Yet, two years later, pilus prevalence re-emerged among non-VT strains to 12.8% of all pneumococci.ConclusionsFollowing PCV implementation, a dramatic and rapid decrease in VT strains prevalence was observed with a concomitant increase in non-VT strains. Piliated strains were nearly eliminated, yet re-emerged 7 years following PCV7/PCV13 implementation in various non-VT strains. This suggests that the pilus confers an advantage in colonization.     

One cross-sectional investigation revealed that non-vaccine serotypes of Streptococcus pneumoniae could be identified more frequently in elderly Chinese people

ObjectiveTo analyze the serotype distribution and drug resistance of Streptococcus pneumoniae isolated from hospitalized patients of all ages in Zhongjiang county, Sichuan province, where the young children have just begun to vaccinate the PCV13 in private sector.MethodsSerotypes were determined for 387 isolates of S. pneumoniae by Quellung reaction. Antibiotic susceptibility was tested with the E-test or disc diffusion method.ResultsThe most common serotypes were type 19F and confirmed for 88 isolates (22.7%), followed by 19A (15.0%), 6B (7.8%), 16F (7.8%), 23F (7.0%) and 15A (4.4%). The coverage rates of PCV13 and PPSV23 were 63.3% and 65.1%. With the increase of age, the proportion of PCV13 types decreased significantly, from 71.3% (<2 years old) to 41.9% (≥60 years old). The intermediate rate and resistance rate of the isolates to oral penicillin were 48.6% and 45.2%, respectively. The resistance rate of erythromycin was high (94.4%). The PCV13 isolates was more resistant to penicillin than the non-PCV13 ones.ConclusionThe PCV13 coverage rate in pediatric isolates was higher than those in adult isolates. The adults, especially the elderly, may be the reservoir of non-PCV13 types. It is necessary to investigate the serotype distribution of S. pneumoniae based on all age population to assess potential epidemics of non-vaccine serotype associated with PCVs administration.     

Distribution, dynamics and antibiotic resistance patterns of Streptococcus pneumoniae serotypes causing acute otitis media in children in southern Israel during the 10 year-period before the introduction of the 7-valent pneumococcal conjugate vaccine

Objectives

To determine the dynamics of serotype prevalence, potential coverage by pneumococcal conjugate vaccines (PCV) and antibiotic resistance patterns of Streptococcus pneumoniae causing acute otitis media (AOM) in children in southern Israel before PCV7 introduction in the routine immunization program in Israel.

Methods

All S. pneumoniae isolates from middle ear fluid from children with AOM during 1999-2008 were included. Prospectively collected demographic data on S. pneumoniae serotypes and antibiotic resistance patterns were analyzed.

Results

A total of 14,911 tympanocenteses yielded 5281(35%) S. pneumoniae. Proportion of S. pneumoniae-AOM did not vary significantly (overall 35%; 33% in 2007; 38% in 2002 and 2003). The most frequent serotypes were 19F, 14, 23F and 19A; in both Jewish and Bedouin children; serotypes 6A and 19A contributed 6% and 10%, respectively, of all S. pneumoniae isolates. Serotypes included in PCV7, PCV10 and PCV13 represented 60%, 64%, 85% in Jewish children vs. 49%, 55% and 74%, respectively, in Bedouin children (P < 0.001). Nonsusceptibility to TMP/SMX decreased significantly, in parallel with a significant increase in the nonsusceptibility to erythromycin, clindamycin and in multidrug resistant (MDR) isolates. No changes were recorded in the proportion of S. pneumoniae isolates with penicillin MIC ≥ 1.0 μg/ml. The proportion of penicillin- and erythromycin-nonsusceptible and of MDR serotype 6A and 19A isolates increased significantly in Bedouin children.

Conclusions

1) No significant changes were recorded in the yearly proportions of serotypes 23F, 19F, 19A, 14 and 6A in both ethnic populations; 2) Potential coverage of the 3 PCVs was higher in Jewish children than in Bedouin children; 3) The relatively high coverage of macrolides- and multidrug-resistant S. pneumoniae by PCV13 and lack of increase in penicillin, erythromycin and multidrug nonsusceptibility among non-PCV13 isolates is encouraging.