123株肺炎链球菌血清分型及耐药性研究

目的了解成都地区123株肺炎链球菌(Streptococcus Pneumoniae,S.p)对常用抗菌药物的耐药性及血清分型。方法用Kirby-Bauer纸片扩散法测定S.p对6种抗菌药物的敏感性,用荚膜肿胀试验进行血清分型。结果123株S.p中,耐阿奇霉素发生率为100%;对米诺环素、复方新诺明、氯霉素、利福平、氧氟沙星的耐药率分别为65.04%、78.05%、19.51%、0.81%、0;血清分型共涉及11个血清型/群,主要集中在19、6、14、15、23血清群,5株S.p未能分型,多重耐药菌株分布在6、19血清群。结论S.p耐药严重,且大多数菌株呈多重耐药趋势;血清分型居前6位的是19F、6、14、15B/C、23F、19A,尤其是多重耐药株以6、19血清群为主。     

疫苗引入前苏州地区儿童肺炎链球菌的分子流行病学特征研究

目的 了解苏州地区在7价肺炎链球菌结合疫苗(7 heptavalent pneumococcal conjugate vaccine,PCV7)引入前,不同临床治疗压力下肺炎链球菌分离株的耐药特征、血清分型及国际流行耐药克隆株(pneumococcal molecular epidemiology network,PMEN)的流行情况.方法 收集2006年3月～2007年3月期间苏州大学附属儿童医院住院治疗的呼吸道感染儿童(病例组)和非呼吸道感染儿童(对照组)中分离的肺炎链球菌134株,进行抗生素敏感性分析和血清型分型,并对其中86株大环内酯类药物菌株进行基因分型.结果 病例组抗生素的使用率高于对照组(x2=111.19,P＜0.001).病例组分离的菌株血清型以19F、19A和14为主,对照组菌株常见的血清型为6B、19F和23F,两组PCV7血清型覆盖率分别为58.3％和68.1％.对照组菌株对常用抗生素的敏感性均高于病例组(均有P ＜0.05).菌株基因分型共检测出10种PMEN克隆株,最常见的为Taiwan19F-14克隆株.PMEN克隆株对常用抗菌药物的不敏感率高于非PMEN克隆株.结论 在我国引入PCV7前,在抗生素等治疗压力下,苏州地区肺炎链球菌的耐药情况严重,以Taiwan19F-14克隆株流行为主,多种PMEN克隆株并存.     

肺炎链球菌的耐药性及其血清型分布调查

目的 了解中山市肺炎链球菌的耐药性及其血清型分布情况，比较正常人群肺炎链球携带株与临床分离株的耐药性与血清型分布关系，探讨肺炎链球菌的耐药性和血清型分布特点。方法 肺炎链球菌的培养、分离和鉴定按《全国临床检验操作规程》进行；药敏试验根据美国临床实验室标准委员会(NCCLS)有关抗生素敏感性试验法规进行试验并对结果进行判定；肺炎链球菌分型使用Quellung反应方法。结果 266株肺炎链球菌中耐青霉素肺炎链球菌占26．7％；耐青霉素肺炎链球菌对红霉素、四环素、氯霉素、克林霉素、利福平和复方新诺明的耐药率高达97．1％、100％、56．3％、84．5％、42．5％、78．9％；在所有菌株中排在前9位(占所有血清型的65．9％)的常见血清型是23F(13．2％)、6A(12．4％)、19F、(10．9％)、6B(7．1％)、14(6．4％)、1．5B(5．3％)、NT(5．3％)、19A(3．0％)、22F(2．3％)。而71株对青霉素不敏感的菌株中排在前9位的常见血清型分别为19F、23F、14型、不能分型、6B、22F、、9V、19B和33F。目前推荐使用的23价肺炎球菌多糖疫苗(1，2，3，4，5，6B，7F，8，9N，9V，10A，11A，12F，14，15B，17F，18C，19A，19F，20，22F，23F，33F、)能覆盖所有分离菌株血清型71．9％。结论 在携带者中，肺炎链球菌对青霉素耐药率已处于较高水平，耐青霉素肺炎链球菌同时对其它常用抗生素普遍耐药，且已发现对三代头孢菌素耐药菌株，对红霉素、四环素、氯霉素、克林霉素材复方新诺明耐药已非常严重；建议对小儿和体弱老人使用23价肺炎球菌多糖疫苗预防接种以减少抗生素的使用和降低耐药菌株出现的压力。     

91株肺炎链球菌的血清型分布及耐药性分析

目的 了解重庆地区肺炎链球菌临床分离株的血清型分布及药物敏感性.方法 采用荚膜肿胀试验进行肺炎链球菌血清学分型,并计算疫苗(PVC7、PVC11、PVC13)覆盖率;肉汤稀释法测定抗菌药物的最低抑菌浓度(MIC).结果 91株肺炎链球菌的临床分离患者年龄呈典型双峰分布,以＜5岁婴幼儿与＞50岁中老年人群为主,占51.7％、27.5％;90株肺炎链球菌共鉴定出20个血清型,1株未能血清分型,常见的肺炎链球菌血清型为19F、19A、6B,PVC13覆盖率为74.4％;91株肺炎链球菌均表现出较高的耐药率,在67株β-内酰胺类抗菌药物不敏感株(BLAs)中,青霉素不敏感菌株(PNSP)占53.8％.结论 重庆地区肺炎链球菌临床分离株以19F、19A、6B血清型为主,PVC13的预防作用更显著;肺炎链球菌耐药性高尤其是大多数菌株呈多药耐药趋势,临床应注意合理选择用药.     

接种13价肺炎球菌结合疫苗对就诊儿童肺炎链球菌血清型和耐药性的影响

  目的  了解就诊儿童肺炎链球菌(Streptococcus pneumoniae, Spn)血清型分布和耐药特征,探索接种13价肺炎球菌结合疫苗(13-valent pneumococcal conjugate vaccine, PCV13)对Spn的影响。  方法  收集2017—2019年苏州大学附属儿童医院疫苗接种信息明确的就诊儿童的Spn菌株,根据疫苗接种情况进行分组,并采用荚膜肿胀法进行血清分型,E-test法检测菌株抗生素的耐药性,比较是否接种PCV13对Spn血清型和耐药性的差别。  结果  共收集692株Spn,其中20株分离自接种PCV13儿童。接种组中常见的血清型为19F、6B、19A、23F,对照组中常见的血清型为19F、6B、23F、19A、14,两组血清型分布差别无统计学意义(P=0.868),PCV13血清型覆盖率分别为70.0% 和72.4%(P=0.491)。所有菌株对红霉素、四环素、克林霉素高度耐药,且多重耐药率达98.5%。接种组和对照组的Spn菌株对青霉素的不敏感率分别为5.0%和9.1%(P=0.804)。  结论  苏州大学附属儿童医院监测就诊儿童Spn血清型以PCV13覆盖的血清型为主,菌株对β-内酰胺类抗生素的耐药性有所下降,但对红霉素等其他常用抗菌药物的耐药性依旧严峻,并存在大量的多重耐药情况。尚未观察到接种PCV13对菌株血清型分布及降低抗生素耐药性的明显效果。     

肺炎链球菌PCR分型技术的建立与应用

目的 建立肺炎链球菌血清型分型的PCR简便方法 ,初步了解肺炎链球菌血清型/群的分布状况.方法 设计合成12种肺炎链球菌血清型/群特异性引物,优化不同血清型/群引物FCR条件,并检测最佳反应浓度、灵敏性以及特异性;初步应用于肺炎链球菌菌株的血清型/群检测.结果引物浓度优化后,12种肺炎链球菌血清型/群特异引物呈现较好的特异性与敏感性;对119株肺炎链球菌菌株进行PCR分型检测,其中113株可分为9个血清型/群(3、5、6A/B、9A/V、14、18、19A、19F、23F),6株未分群.结论 初步建立了12种血清型/群肺炎链球菌PCR分型技术,可用于鉴别人群中主要流行的肺炎链球菌血清型/群.     

温州地区青霉素不敏感肺炎链球菌临床分离株的血清分型及耐药性分析

目的评价青霉素的体外药敏试验的检测方法,探讨青霉素不敏感肺炎链球菌(penicillin-nonsusceptible Streptococcus pneumoniae,PNSP)临床分离株的主要血清型、耐药特性及流行特征。方法从温州市中西医结合医院WHONET5.6分析系统筛选出2013-2017年肺炎链球菌1 006株,用E-test法确认青霉素的体外抗菌活性,荚膜肿胀试验进行血清型分型,用VITEK-2 Compact全自动细菌分析仪药敏系统判定药物敏感性,分析不同血清型对常用抗菌药物的耐药率。结果筛选获得602株PNSP菌株,不敏感率59.84%;进一步经E-test法复核,仅86株PNSP,不敏感率8.55%,两种检测方法比较差异具有统计学意义(χ~2=588.100,P<0.001);年龄以<5岁儿童为主;主要血清型分别为19A、19F、23F、6B、4、14,以19A、19F为主,分别占32.56%和23.26%;不同血清型PNSP对喹诺酮类、万古霉素和利奈唑胺具有高度的敏感性,19F和19A对β-内酰胺类药物耐药率较高;6B和23F对β-内酰胺类药物耐药率较低。结论肺炎链球菌血清流行病学分布的研究对于制订疫苗使用策略有着至关重要的意义,应及时监控PNSP血清流行病分布和耐药性变化。     

12种抗菌药物对广东省不同血清群脑膜炎奈瑟菌敏感性分析

目的了解广东省不同血清群脑膜炎奈瑟菌（Nm）对12种抗菌药物的敏感性。方法采用纸片扩散（K—B）法和E．test法,对广东省67株Nm菌株进行体外12种抗菌药物敏感性检测。结果67株脑膜炎奈瑟菌对6种治疗药物（青霉素、氨苄西林、头孢噻肟、头孢曲松、关罗培南和氯霉素）和3种预防用药物（阿奇霉素、米诺环素和利福平）全部敏感,对另外3种预防用药物（环丙沙星、萘啶酸、甲氧苄啶／磺胺甲恶唑）则有不同程度的耐药,耐药率分别为50．75％（34／67）、55．22％（37／67）和92．54％（62／67）。不同来源的Nm菌株对环丙沙星、萘啶酸的耐药率差异均有统计学意义（均JP〈0．01）,对这2种药物的耐药率均以密切接触者菌株的耐药率最高,分别为70．6％（12／17）和88．2％（15／17）;而对甲氧苄影磺胺甲恶唑的耐药率差异无统计学意义（P〉0．05）。B群和C群菌株对3种抗菌药物的耐药率差异均有统计学意义（P〈0．05或P〈0．01）,而未定群和W135群菌株对3种抗菌药物的耐药率差异均无统计学意义（均P〉0．05）。C群出现两重和三重耐药的耐药率分别为80．6％（29／36）、63．9％（23／36）。结论广东省不同血清群Nm菌株对环丙沙星、萘啶酸、甲氧苄啶／磺胺甲恶唑3种抗菌药物表现出不同程度的耐药性,且发现多重耐药菌株,对Nm进行长期实时的药物敏感性监测非常必要。     

152株肺炎链球菌的耐药性及血清分型研究

目的 了解武汉地区肺炎链球菌对常用抗菌药物的耐药性及血清型分布.方法 琼脂稀释法测定152株肺炎链球菌对15种抗菌药物最低抑菌浓度,荚膜肿胀试验进行血清学分型.结果 152株肺炎链球菌中,耐青霉素肺炎链球菌（PRSP,MIC≥0.12 mg/L）的发生率为42.76%;第一、二、三代头孢菌素的耐药率依次降低,分别为94.08%、50.66%、41.45%和11.18%;红霉素、四环素、复方新诺明和氯霉素耐药率分别为84.21%、88.82%、89.47%和18.42%;新喹诺酮类左氧氟沙星和莫西沙星的耐药率均为1.32%;血清分型共涉及20个血清型、群,主要集中在19、23、6、15和14血清群,PRSP分布在6、19、23和未分型血清群.结论 武汉地区肺炎链球菌耐药性高,应注意合理选择用药;血清分型,尤其多重耐药株以6、19和23血清群为主,推荐疫苗免疫预防肺炎链球菌感染.     

马鞍山市肺炎链球菌血清型分布及耐药性分析

目的了解马鞍山地区肺炎链球菌临床分离株的血清型分布及药物敏感性。方法应用奥普脱欣试验及胆汁溶解试验鉴定肺炎链球菌;采用荚膜肿胀试验进行肺炎链球菌血清学分型,计算PPV23价疫苗及PCV7疫苗覆盖率;K-B法测定8种药物的耐药试验。结果 80株肺炎链球菌共鉴定13种血清型,有5株不能定型或群,马鞍山地区相对的优势血清型以19F、19A、23F为主,PPV23价疫苗可覆盖本次测试株的86.42%,PCV7疫苗可覆盖测试株的55.56%血清型;75株测试菌对青霉素等药物耐药率较高,耐受四种以上药物的菌株达60株,占测试菌株的80.00%,所有测试菌对左氧氟沙星和万古霉素全部敏感。结论马鞍山地区肺炎链球菌临床分离株以19F、19A、23F血清型为主,PPV23价疫苗的预防作用更显著;绝大多数肺炎链球菌呈多药耐药趋势,应注意合理用药。     

Antimicrobial susceptibility and serotype distribution of Streptococcus pneumoniae isolated from patients with community-acquired pneumonia and molecular analysis of multidrug-resistant serotype 19F and 23F strains in Japan

A nationwide study was undertaken to determine the susceptibility to penicillin and serotypes of Streptococcus pneumoniae in Japan. S. pneumoniae was isolated from 114 adult patients with community-acquired pneumonia over 22 months at 20 hospitals and medical centres in different regions in Japan. All but five isolates were from sputum. Forty-eight isolates (42.1%) were susceptible, 40 (35.1%) showed intermediate resistance (MIC, 0.12-1.0 microg/ml) and 26 (22.8%) were resistant (MIC, >or=2.0 microg/ml) to penicillin G. All isolates were susceptible to ceftriaxone (breakpoint 1 microg/ml), imipenem (4 microg/ml) and vancomycin (4 microg/ml). Most were resistant to erythromycin, clarithromycin and azithromycin; only two were resistant to levofloxacin. Differences were found in the distribution of serotypes among isolates showing susceptibility to penicillin (predominant types 3, 6B, and 19F), intermediate resistance (6B, 14, 19F, and 23F) and full resistance (19F and 23F). PFGE typing showed that 14 of the 25 strains of serotype 19F had a single DNA profile, pattern A, a pattern closely similar to that of the Taiwan multidrug-resistant 19F clone. Twelve pattern A strains were not susceptible to penicillin but carried the macrolide resistance gene mef(A). The DNA profiles of the 15 strains of 23F were also heterogeneous but six were highly similar (pattern b) yet distinct from the Spanish multidrug-resistant 23F clone although possibly related to the Taiwan multidrug-resistant 23F clone. The pattern b strains were not susceptible to penicillin and also harboured either mef(A) or erm(B). Our results indicate that multidrug-resistant pneumococci are spreading rapidly in Japan. Efforts to prevent the spread of the pandemic multidrug-resistant serotypes should be intensified.     

Nasopharyngeal carriage of Streptococcus pneumoniae in healthy children: implications for the use of heptavalent pneumococcal conjugate vaccine

We assessed the prevalence of Streptococcus pneumoniae serotypes in the nasopharynx of healthy children, antimicrobial susceptibility patterns, risk factors for carriage, and the coverage of heptavalent pneumococcal conjugate vaccine. In 2,799 healthy infants and children, the S. pneumoniae carrier rate was 8.6% (serotypes 3, 19F, 23F, 19A, 6B, and 14 were most common). Most pneumococci (69.4%) were resistant to one or more antimicrobial classes. The rate of penicillin resistance was low (9.1%); macrolide resistance was high (52.1%). Overall, 63.2% of the isolates belonged to strains covered by the heptavalent pneumococcal vaccine. This percentage was higher in children <2 years old (73.1%) and in those ages 2-5 years (68.9%). Sinusitis in the previous 3 months was the only risk factor for carrier status; acute otitis media was the only risk factor for the carriage of penicillin-resistant S. pneumoniae. Most isolated strains are covered by the heptavalent conjugate vaccine, especially in the first years of life, suggesting that its use could reduce the incidence of pneumococcal disease.     

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.     

Dynamics of Streptococcus pneumoniae nasopharyngeal carriage with high heptavalent pneumococcal conjugate vaccine coverage in Central Greece

In order to study whether the use of the heptavalent pneumococcal conjugate vaccine (PCV7) led to a shift in the Streptococcus pneumoniae serotypes distribution and whether it modified the resistance to antibiotics, 2649 nasopharyngeal samples were obtained between 2005 and 2009, from children attending day-care centers in Central Greece. The percentage of attendees vaccinated with ≥1 dose of PCV7 increased from 12.9% (2005) to 95.5% (2009). Non-PCV7 serotypes replaced those belonging to PCV7. In 2009, 19F was virtually the only PCV7 serotype that continued to circulate. A significant increase in the frequency of penicillin-intermediate (oral penicillin V breakpoints) isolates coincided with a marked reduction in isolates with high resistance to penicillin. Several non-PCV7 serotypes colonized the children, but their frequency varied substantially from year to year. Each one of 14 specific non-PCV7 serotypes, i.e. 6A, 11A, 15B, 23A, 10A, 16F, 38, 22F, 15C, 19A, 35F, 24F, 6C, and 7F, accounted for ≥2% of pneumococcal isolates in at least 2 annual surveillances. An increase in non-PCV7 serotypes with antibiotic resistance, beyond 6A and 19A, occurred. Intermediate resistance to penicillin was observed in serotype 23B, 15B, 15C, 15A, 35F, 6C, and 24F pneumococci. Their exact role in invasive and non-invasive disease remains to be seen in the years ahead.     

Current trend of pneumococcal serotypes distribution and antibiotic susceptibility pattern in Malaysian hospitals

From January 2008 to December 2009, 433 Streptococcus pneumoniae strains were examined to determine the serotype distribution and susceptibility to selected antibiotics. About 50% of them were invasive isolates. The strains were isolated from patients of all age groups and 33.55% were isolated from children below 5 years. The majority was isolated from blood (48.53%) and other sterile specimens (6.30%). Community acquired pneumonia (41.70%) is the most common diagnosis followed by sepsis (9.54%). Serotyping was done using Pneumotest Plus-Kit and antibiotic susceptibility pattern was determined by modified Kirby-Bauer disk diffusion method and measurement of minimum inhibitory concentration (MIC) using E-test strip. Ten most common serotypes were 19F (15.02%), 6B (10.62%), 19A (6.93%), 14 (6.70%), 1 (5.08%), 6A (5.08%), 23F (4.85%), 18C (3.93%), 3 (2.08%) and 5 (1.85%). Penicillin MIC ranged between ≤0.012-4 μg/ml with MIC₉₀ of 1 μg/ml. Penicillin resistant rate is 31.78%. The majority of penicillin less-susceptible strains belonged to serotype 19F followed by 19A and 6B. Based on the serotypes distribution 22 (44.00%), 28 (56.00%) and 39 (78.00%) of the invasive isolates from children ≤2 years were belonged to serotypes included in the PCV7, PCV10 and PCV13, respectively.