中国儿童侵袭性肺炎链球菌耐红霉素株的流行病学特征

目的:检测中国儿童侵袭性肺炎链球菌耐红霉素株的耐药基因,并分析其流行病学特征。方法：对2006-2008年间从全国11个医疗中心收取的,共171株侵袭性肺炎链球菌株进行血清分型和药敏试验。对其中耐红霉素株进行耐药基因检测、多位点序列分析和脉冲场凝胶电泳分析。结果：共有164株(95.9%)对红霉素耐药,除了2株细菌以外都呈现出高水平耐药(MIC≥256μg/ml)。其中有104(63.4%)株只携带ermB基因,59(36.0%)株同时携带ermB和mefA基因,仅1株细菌单独携带mefA基因。同时携带2个耐药基因的血清型主要是19A和19F,它们都显示同样的PFGE形式（C型）。结论：中国儿童的侵袭性肺炎链球菌红霉素耐药率很高,其主要的耐药机制是由ermB基因介导的。同时携带ermB 和mefA两种耐药基因的血清型主要是19A和19F,它们与Taiwan19F-14 克隆具有遗传相关性。     

Serological and molecular capsular typing, antibiotic susceptibility and multilocus sequence typing of Streptococcus pneumoniae isolates from invasive and non-invasive infections

Background Streptococcus pneumoniae (S. pneumoniae) is a major causative agent of severe infections, including sepsis, pneumonia, meningitis, and otitis media, and has become a major public health concern. We report the pneumococcal serotype and sequence type (ST) distribution, and antimicrobial resistance of 39 S. pneumoniae strains from seven hospitals in China.

Methods Blood/cerebrospinal fluid (CSF) and sputum isolates from patients were analyzed to determine S. pneumoniae serotypes by polymerase chain reaction (PCR) and the Neufeld Quellung reaction, the multilocus sequence types (MLST) by PCR and sequencing, and susceptibility to antimicrobial agents by the VITEK Gram Positive Susceptibility Card.

Results A total of 39 isolates were collected including 21 blood/CSF and 18 sputum isolates. Conventional serotyping by the Quellung reaction required 749 reactions. In contrast, PCR based typing needed only 106 PCR reactions. The most frequent serotypes from the blood/CSF isolates were 14 (38.1%), 19A (14.3%), 23F (9.5%), and 18C (9.5%). In the sputum isolates the most frequent serotypes were 19F (33.3%), 23F (16.7%), 19A (11.1%), and 3 (11.1%). The incidence of penicillin resistance in the blood/CSF and sputum isolates was 66.7% and 55.6%, respectively. Statistical analysis showed that patients ≤5 years old had a higher resistance to penicillin when they compared with the patients ≥65 years old (P=0.011). Serotypes 14, 19A and 19F were significantly associated with penicillin resistance (P <0.001). ST320, ST271, and ST876 isolates showed high resistant rates to several antibiotics including penicillin (P=0.006). All of the isolates of serotype 19A were resistant to both penicillin and erythromycin, and they were all multi-drug resistant (MDR) isolates.

Conclusions The specificity and sensitivity of multiplex-PCR are good, and this method represents a substantial savings of time and money, and can be widely used in the laboratory and clinical practice. Data from this research showed an extremely high prevalence of penicillin resistance and an increasing prevalence of multi-drug resistant (MDR) rate in S. pneumoniae. A distinctive emergence of serotype 19A was observed which was also associated with the increasing prevalence of antimicrobial resistance. Therefore, nationwide surveillance of pneumococcal resistance and serotypes is strongly warranted.

     

侵袭性肺炎链球菌148株血清型、耐药性及分子分型研究

目的 研究临床分离的侵袭性肺炎链球菌血清型分布、耐药性及分子流行病学特点,为抗生素的应用和免疫预防提供参考依据.方法 收集2005年1月至2008年8月全国15个地区148株来自血液、脑脊液等侵袭性感染部位的肺炎链球菌.采用琼脂稀释法测定青霉素等抗生素对148株肺炎链球菌的最低抑菌浓度(MIC);采用简易棋盘式肺炎链球菌分型系统和荚膜肿胀实验进行血清分型;多位点序列分型(MIST)技术对53株19群菌株进行基因分型,了解其与国际流行株的关系.结果 血清分型共检出20个血清型/群,主要集中在19A、19F、3、23F、5、6、14和9血清型/群,共计105株,占70.9%,以19A(22.3%,33/148)、19F(16.9%,25/148)最常见,其次为3群(7.4%,11/148)和23F(6.8%,10/148).7价疫苗(PCV7)在2岁以下儿童中的覆盖率为33.3%(12/36).PCV7相关血清型肺炎链球菌对阿莫西林/克拉维酸、红霉素等耐药率均明显高于非疫苗相关血清型菌株(P<0.05).53株19群肺炎链球菌MIST分析共检出9种序列型(ST),其中以ST320(28/53,52.8%)和ST271(12/53,22.6%)为主.结论 我国侵袭性肺炎链球菌血清分型以19A、19F、3和23F血清型为主.侵袭性肺炎链球菌耐药情况严重.     

呼吸道感染婴幼儿肺炎链球菌的耐药性及青霉素结合蛋白基因突变分析

目的 分析呼吸道感染婴幼儿肺炎链球菌的耐药性及青霉素结合蛋白基因(PBPs)突变情况.方法 收集呼吸道感染婴幼儿痰或咽拭子标本中分离出的24株肺炎链球菌,进行菌株鉴定和药敏试验.对筛选出的耐青霉素肺炎链球菌行耐药性分析,并提取菌株DNA后分析PBPs基因突变情况.结果 24株肺炎链球菌中,青霉素不敏感菌株有13株,占54.2％;13株青霉素不敏感菌株对对氨苄西林、阿莫西林/克拉维酸和头孢呋辛不敏感率较高,分别为100％、76.9％和76.9％;对头孢噻肟、头孢曲松和头孢吡肟的不敏感率较低,分别为46.2％、38.5％和30.8％;对美罗培南和万古霉素的不敏感率最低,分别为15.4％和0.13株青霉素不敏感菌株未发现pbp1a基因突变菌株,5株存在pbp2b基因突变,占38.5％.结论 青霉素不敏感肺炎链球菌存在对多种抗生素耐药情况,而pbp2b基因突变可能是导致肺炎链球菌耐药的重要原因,应加强肺炎链球菌耐药性及PBP基因突变监测.     

肺炎链球菌对红霉素耐药机制的研究

目的了解武汉地区肺炎链球菌的红霉素耐药机制。方法收集152株肺炎链球菌，琼脂稀释法测定抗菌药物最低抑菌浓度，红霉素-克林霉素双纸片扩散法检测耐药表型，聚合酶链式反应检测红霉素耐药基因ermB和mefA。结果152株肺炎链球菌红霉素耐药率达84．21％（128／152），耐药表型主要为cML SB（98．44％），2抹菌（1．56％）为M表型耐药。128株红霉素耐药肺炎链球菌ermB基因总检出率98．44％（126／128），其中40株菌（31．25％）同时检出ermB和mefA基因，2株菌（1．56％）仅检出mefA基因。结论武汉地区红霉素耐药肺炎链球菌的发生率高，ermB基因是最主要的耐药机制，介导cMLSa表型耐药，双纸片扩散法对此耐药表型的检测有很好的预见性。     

Prevalence of antimicrobial resistance of Streptococcus pneumoniae in Chinese children: four hospitals surveillance

Objective To investigate the nasal carriage of antibiotic-resistant pneumococci in children of &lt;5 years old in the following four cities, Beijing, Shanghai, Guangzhou and Xi’an.Methods A total of 647 pneumococci strains were isolated and detected. Minimal inhibition concentrations (MICs) of antibiotics were determined by E-test. Disk diffusion test was used for the measurement of antimicrobial susceptibility.Results Prevalence of penicillin non-susceptible Streptococcus pneumoniae in the four cities was 41%, with Guangzhou (60.8%) ranking first, followed by Xi’an (45%), Shanghai (37%) and Beijing (25.9%). The majority of penicillin non-susceptibility isolates (23.9%-53.8%) had a low level of resistance (MIC 0.64-1.5 μg/ml). The most sensitive antimicrobials in terms of percentage of susceptible organisms were amoxicillin-clavulanic acid (99.4%), followed by ceftriaxone (92.1%); cefurxime and cefaclor were slightly more sensitive than penicillin with susceptibility of 74.8% and 77.9%. Erythromycin, tetracycline and TMP-SMZ were highly resistant (83.6%, 82.1% and 76.2% respectively). Among erythromycin resistant isolates, 100% were resistant to azithromycin, 98.6% to clarithromycin, 97.2% to roxithromycin and spiramycin, and 96.6% to clindamycin. 97.2% (141/145) were typical of the macrolides-lincosamides-streptogramons B (MLSB ) resistance phenotype, and 2.8% (4/145) were M phenotype. The group of PRSP was with significantly higher rates of non-susceptibility for ceftriaxone (18.4%), cefurxime (58.6%), cefaclor (53.4%), compared with the group of PEN-S (0.5%, 1.8% and 0.2%, respectively) and the rate of multi-drug resistance in the isolates of PRSP group (92.9%) was significantly higher than that of PEN-S group (59.2%).Conclusion The rates of penicillin and multi-drug resistance among isolates of pneumococci carried nasally in are high children and the high prevalence of multi-drug resistance in the Chinese population may be becoming one of the most serious problems in this century.     

苏州地区临床分离儿童肺炎链球菌耐药情况分析

 目的 检测苏州地区2006年临床分离的儿童肺炎链球菌对常用抗生素的耐药情况。方法 从新入院患儿鼻咽部采集标本,经实验室分离,并采用奥普托欣和（或）去氧胆酸钠鉴定为肺炎链球菌后,采用纸片扩散法（Kirby-Bauer法）和E-test法对分离到的89株肺炎链球菌进行抗生素的敏感性试验。结果 89株肺炎链球菌中,青霉素不敏感菌株47株,为52.8%,红霉素、四环素、克林霉素、复方新诺明和氯霉素的耐药率分别为88.8%,78.7%,86.5%,55.1%和10.1%,多重耐药率为89.9%。对万古霉素,氧氟沙星100%敏感。结论 苏州地区儿童肺炎链球菌的耐药情况严峻,本研究结果对肺炎链球菌感染的治疗和抗菌药物的选择具有参考价值。     

儿童感染侵袭性肺炎链球菌耐药基因和毒力基因携带分析

目的 了解河北省侵袭性肺炎链球菌耐药基因和毒力基因携带情况,为利用全基因测序手段研究耐药机制及致病机理打下基础。方法 对2017—2018年收集从儿童病例分离并保存河北省疾病预防控制中心的75株侵袭性肺炎链球菌,使用普通PCR方法检测侵袭性肺炎链球菌菌株研究报道较多的耐药基因和毒力基因,并分析携带情况。结果 青霉素耐药相关pbp2b基因携带率为0,红霉素耐药相关ermB、ermA和mefA/E基因携带率分别为96.00%、0和33.33%,四环素耐药相关tetM、tetL、tetK和tetO基因分别为94.67%、84.00%、0和0,左氧氟沙星耐药相关gyrA基因97.33%;主要毒力基因携带率自溶酶和神经氨酸酶表达相关基因lytA、lytB、nanA均为100.00%;与菌体侵入机体过程相关的pav、ply、hysA、iga基因分别为97.33%、98.67%、93.33%、96.00%;与细菌粘附相关的rrgA基因为29.33%;肺炎链球菌表面蛋白相关基因pspA与pspC携带率为0%。血清14、19F、6、23F型菌株mefA/E基因携带率较高,携带rrgA基因的株菌中19F型最多（9/22）;不携带tetL基因的菌株中6型占33.3%。结论 河北省侵袭性肺炎链球菌携带ermB、tetM和tetL基因及gyrA基因比例较大,应警惕此类菌株对大环内酯类、四环素类、氟喹诺酮类抗生素的耐药性。lytA、lytB基因携带率高应慎用β-内酰胺类抗生素。菌株毒力基因携带率具有地区差异,建议结合临床表现,深入研究并长期监测。     

肺炎链球菌毒力蛋白DNA疫苗优势抗原组合筛选及鉴定

目的 探讨肺炎链球菌DNA疫苗候选抗原联合免疫的优势抗原组合方式.方法 分子克隆肺炎链球菌表面蛋白A(PspA)N端及肺炎链球菌溶血素(Ply)基因序列,构建重组质粒pcDNA3.1-PspA'和pcDNA3.1-PBD(PBD为Ply 点突变减毒体),免疫印迹(Western blot)检测重组质粒在哺乳动物BHK-21细胞中的表达(包括前期工作中构建的重组质粒pcDNA3.1-PsaA).将3种重组基因疫苗以不同方式组合肌肉注射免疫150只BALB/c小鼠(B组:pcDNA3.1-PsaA+pcDNA3.1-PspA',C组:pcDNA3.1-PsaA+pcDNA3.1-PBD,D组:pcDNA3.1-PspA'+pcDNA3.1-PBD,E组:pcDNA3.1-PsaA+pcDNA3.1-PspA'+pcDNA3.1-PBD),检测各组小鼠血清特异性抗体IgG水平,观察免疫小鼠鼻咽部肺炎链球菌D39携带改变和D39腹腔攻击小鼠21 d生存情况.结果 成功构建3种重组真核表达载体,ELISA检测结果显示B组小鼠血清特异性IgG抗体水平与E组相似(P>0.05),均明显高于A、C、D组[A组:对照空质粒组pcDNA3.1(+)]小鼠(P<0.01);免疫小鼠鼻咽部D39携带菌落计数提示B组小鼠相似于E组小鼠(P>0.05),并明显少于C、D组和阴性对照组(A组和PBS组,P<0.01),并且D39腹腔攻击小鼠21 d生存时间分析亦提示其中位生存时间明显长于C组及阴性对照组(A组和PBS组,P<0.01).结论 PspA'联合PsaA的抗原组合方式具有高效的协同保护效能,可作为肺炎链球菌DNA疫苗的优势候选抗原组合.     

A single tube modified allele-specific-PCR for rapid detection of erythromycin-resistant Mycoplasma pneumoniae in Beijing

Background  Mycoplasma pneumoniae (M. pneumoniae) is one of the common pathogens causing atypical pneumonia. In recent years, resistance to macrolides has become more common, especially in China. Previous studies have confirmed that the mutation at position 2063 in domain V of the 23S rRNA is the most prevalent, followed by the mutation at position 2064. Reported molecular detection methods for the identification of these mutations include direct sequencing, restriction fragment length polymorphism analysis, real-time polymerase chain reaction (PCR) with high-resolution melt analysis, and nested PCR-linked with capillary electrophoresis, etc. The most commonly used method for monitoring resistance-conferring mutations in M. pneumoniae is direct DNA sequencing of PCR or nested PCR products. However, these methods are time-consuming, labor-intensive or need expensive equipments. Therefore the development of rapid and sensitive methods is very important for monitoring the resistance globally.

Methods  In this study, we reported a fast and cost-effective method for detecting 2063 and/or 2064 macrolide resistant mutations from specimens using a modified allele-specific PCR analysis, and all results were compared with the sequencing data. We also analyzed the clinical courses of these samples to confirm the modified allele-specific PCR results.

Results  Among 97 M. pneumoniae specimens, 88 were found to possess mutations by this method, and all modified allele-specific PCR analysis results were consistent with the sequencing data. The data of the clinical courses of these 97 cases showed that they suffered from severe pneumonia. Erythromycin showed better efficacy on cases from which no macrolide resistance mutation was found on their specimens. However, in some cases from which mutations were detected, erythromycin monotherapy had poor efficacy, and on these patients severe symptoms improved only when azithromycin was added to the treatment.

Conclusions  The drug-resistant M. pneumoniae is very common in Beijing, China. Our modified allele-specific PCR analysis can identify erythromycin resistant mutations more rapidly from specimens than any other method currently available. Erythromycin is still effective for treating patients infected with the mutation negative M. pneumoniae, but this treatment fails to work on mutant organisms. This method can facilitate clinicians in selecting appropriate therapy within short timescales.

     

肺炎链球菌抗原试验快速检测阳性血培养瓶肺炎链球菌

目的 探讨肺炎链球菌抗原用于辅助诊断阳性血培养瓶肺炎链球菌的临床意义.方法 采用双盲法检测人工模拟血培养链球菌阳性标本34例人工模拟血培养链球菌阴性标本180例,血培养仪报警后,移出培养瓶用注射器抽取部分血培养液,部分用于革兰染色,部分用于肺炎链球菌抗原试验和标准培养鉴定法试验.结果 34例链球菌阳性标本中,肺炎链球菌24例,肺炎链球菌抗原试验均为阳性,缓症链球菌2例和血链球菌1例,肺炎链球菌抗原试验亦为阳性,7例其它链球菌肺炎链球菌抗原试验阴性.结论 肺炎链球菌抗原试验可应用于阳性血培养瓶肺炎链球菌的快速鉴定.     

Clinical outcome of invasive infections in children caused by highly penicillin-resistant Streptococcus pneumoniae compared with infections caused by penicillin-susceptible strains

BACKGROUND: In this report based on data from the Institutional Surveillance System during 1994-1998, we document the continuing emergence of drug-resistant Streptococcus pneumoniae strains at the Hospital Infantil de Mexico Federico Gómez in Mexico City. METHODS: We evaluate the clinical course of 49 invasive pneumococcal infection outside the central nervous system (CNS) by a number of factors including the site, severity, and place where the infection was acquired, the underlying health of the patient, and the adequacy of antimicrobial therapy. RESULTS: An underlying illness was present in 21 of 49 (43%) patients, 37 (75%) patients had taken previous antimicrobial therapy, and 25% of the infections were nosocomially acquired. Overall, 25 of 49 (51%) of the pneumococcal strains tested were pencillin-resistant; strains with the highest resistance to penicillin were also resistant to cephalosporins. Twenty-two percent of all strains were considered to be multidrug-resistant. Eleven of 25 penicillin-resistant strains were identified as multidrug-resistant, i.e., to erythromycin, TMP/SMX, and chloramphenicol. Ten serotypes accounted for 88% of the isolates, the most frequent serotypes being 23F, 14, 19V, 6A, and 6B. The overall case-fatality rate was 37% (18 of 49), with most deaths occurring within 3-5 days after antibiotic therapy was initiated. There was no difference in the case fatality rate between children with penicillin-nonsusceptible and penicillin-susceptible pneumococcal infections; instead; case-fatality rate correlated with severity of illness on admission and presence of underlying disease. CONCLUSIONS: Characterizing groups at risk for invasive pneumococcal disease could aid in the development of preventive programs and increase the benefits from wide use of future conjugated vaccines.     

91例肺炎链球菌药敏分析

目的:研究某地区肺炎链球菌的耐药情况,以指导抗菌药物的合理应用。方法:用琼脂稀释法以及折点法测定12种抗菌药物,对91例肺炎链球菌的最低抑菌浓度(MIC)。结果:91例肺炎链球菌对12种抗生素的敏感率依次为:万古霉素(100.0%)、利福平(97.8%)、氧氟沙星(96.7%)、亚胺培南(93.4%)、左氧氟沙星(92.3%)、头孢噻肟(74.7%)、氯霉素(69.2%)、阿莫西林(68.1%)、青霉素(68.1%)、四环素(12.1%)、红霉素(9.9%)、复方新诺明(8.8%)。结论:肺炎链球菌对大多数抗菌素有不同程度的耐药性(万古霉素除外),同时亦存在交叉耐药现象。     

Nasal carriage of Streptococcus pneumoniae among children in Beijing

目的　了解北京地区儿童鼻部携带的肺炎链球菌对抗生素的敏感性以及血清型分布 ,分析鼻部携带青霉素非敏感肺炎链球菌的危险因素。方法　用纸片扩散法检测肺炎链球菌对红霉素 ,复方新诺明 ,氯霉素和四环素的敏感性 ;E -试验确定青霉素 ,头孢呋新 ,头孢噻肟 ,安灭菌和亚胺培南的最小抑菌浓度 ;Quellung反应确定肺炎链球菌的血清型。结果　未发现对青霉素和头孢呋新高度耐药的肺炎链球菌 ,但对青霉素和头孢呋新中度耐药的肺炎链球菌分别占 8 2 %和 2 1%。所有菌株均对头孢噻肟 ,安灭菌和亚胺培南敏感。对红霉素 ,复方新诺明和四环素耐药的肺炎链球菌特别多 ,分别占 72 % 70 %和 79%。所有肺炎链球菌中 ,有 5种血清型 (19,6 ,14 ,2 3,17)共占 5 4 7% ,不定型占 2 0 6 %。既往中耳炎病史是鼻部携带青霉素非敏感肺炎链球菌的危险因素。结论　连续监测肺炎链球菌对抗生素的敏感性具有重要意义。需要进行更大规模的研究以明确目前的 7价或 9价肺炎链球菌结合疫苗是否适合中国儿童     

肺炎链球菌对青霉素耐药率的调查

目的 调查了解北京地区肺炎链球菌对青霉素及其他１２种抗生素的耐药情况,方法 对北京儿童医院及北京医科大学第一医院儿科６个月至３岁的门诊及入院首日患儿进行咽拭子标本采集,并迅速接种于平皿中过夜孵育,分离鉴定肺炎链球菌并选用苯唑西林,氯霉素,四环素,头孢曲松及红霉素纸片作药敏试验,用琼脂扩散法作最小抑菌浓度（ＭＩＣ）试验。结果 ９８９个咽拭子标本中共分离出５１株肺炎链球菌,经用 唑西林纸片初步筛选,青     

苏州地区儿童肺炎链球菌脑膜炎39例临床特征和血清型分析*

目的：分析苏州地区儿童肺炎链球菌脑膜炎及死亡病例的血清型和临床特征,寻找降低儿童肺炎链球菌脑膜炎发病率和死亡率的对策。方法：对苏州大学附属儿童医院2011年1月—2016年12月收治97例化脓性脑膜炎患儿中39例肺炎链球菌脑膜炎菌株进行血清学分型,对其临床特征和实验室结果进行统计分析。结果：97例化脓性脑膜炎患儿脑脊液培养出致病菌依次为：肺炎链球菌39例(40.2%),无乳链球菌19例(19.6%)和大肠埃希菌18例(18.6%)等;总病死率为19.6%(19/97),按照病死率高低依次为：肺炎克雷伯菌60.0%(3/5),肺炎链球菌35.9%(14/39)和大肠埃希菌11.1%(2/18);肺炎链球菌脑膜炎死亡组体温＞40°、早期纳差、早期嗜睡、休克、弥散性血管内凝血、急性肾损伤、呼吸衰竭、抽搐和昏迷的发生显著高于存活组(P＜0.05);肺炎链球菌组分别有17.9%和15.4%出现并发症硬膜下积液和脑积水;肺炎链球菌组首次抗生素使用与药敏结果符合率为20.0%(6/30);39例肺炎链球菌脑膜炎患儿肺炎链球菌疫苗率为0.0%,7价肺炎链球菌疫苗和13价肺炎链球菌疫苗覆盖肺炎链球菌组血清型分别为82.1%和92.3%,对死亡组血清型覆盖率分别是85.7%和92.9%。结论：肺炎链球菌是苏州地区6个月以上儿童化脓性脑膜炎的首要病原体;早期识别高热、纳差和嗜睡等危重症状态及合理选择抗生素对改善肺炎链球菌脑膜炎预后具有重要意义。门诊抗生素选择对肺炎链球菌敏感率低及我国肺炎链球菌疫苗接种率低,是肺炎链球菌脑膜炎高病死率的重要原因。期望通过接种13价肺炎链球菌结合疫苗降低肺炎链球菌脑膜炎的发生率和病死率。     

PspA免疫小鼠抗肺炎链球菌侵袭性感染研究

目的:获取原核表达的肺炎链球菌PspA重组蛋白并研究其作为疫苗的价值. 方法:分离培养肺炎链球菌TIGR4,获取其染色体DNA,采用基因体外重组法将编码PspA抗原表位在内的部分序列克隆到原核表达载体PET-32(a)内,酶切及测序鉴定重组质粒转化到大肠杆菌BL21(DE3)中,经IPTG诱导,将获得的重组蛋白用Western Blot鉴定,镍柱纯化并透析除盐. 用重组蛋白免疫动物,观察PspA抗体对肺炎链球菌感染小鼠的保护作用. 结果:DNA序列与GenBank中的数据相符,所表达纯化的蛋白经Western Blot证实为PspA,其抗体在肺炎链球菌感染中对小鼠有保护作用. 结论:重组PspA刺激产生的抗体能够有效抵抗肺炎链球菌TIGR4侵袭性感染,该重组蛋白可作为肺炎链球菌多肽联合疫苗的组成部分之一.     

肺炎链球菌临床分离株耐药性及红霉素耐药相关基因的研究

目的了解本院临床肺炎链球菌感染状况、耐药性以及耐药基因流行情况。方法2004年1月~2005年12月从患者不同标本分离鉴定肺炎链球菌,采用NCCLS标准K-B法对临床常用抗生素进行耐药分析、PCR检测红霉素耐药基因ermB和mefA。结果分离129株肺炎链球菌,其中青霉素敏感率为42.4%,红霉素耐药率为80.6%。104株红霉素耐药肺炎链球菌中,ermB基因检出率为97.1%,mefA基因检出率为41.3%,41株同时含有ermB和mefA基因。结论本院临床分离肺炎链球菌耐药性高,红霉素耐药基因主要为ermB。     

上海市791名健康儿童222株肺炎链球菌携带株研究

目的 了解健康儿童肺炎链球菌携带株的流行病学特征。方法 测定来自上海5所幼儿园（代号分别为JR、PL、SY、WS、ZF）791名健康儿童鼻咽部分离的222株肺炎链球菌健康儿童携带株的耐药谱和血清型,并以PFGE、BOX、PGR和pbp基因指纹等分子生物学方法分析菌株间亲缘关系。结果 222株携带株中有青霉素低度耐药株32株,未发现青霉素高度耐药株,全部菌株包括22种血清型,常见为23F（25.7%),6A（13.1%)、19F（10.8%)、6B（8.1%)等;青霉素低度耐药株包括8种血清型,主要为23F（50%）、19A和19F（各占15.6%)。32株青霉素低度耐药菌株可分为8种BOXPCR谱型和7种PFGE谱型。PFGE谱型A菌株的耐药谱,血清型以及BOXPCR和pbp基因指纹高度一致。自幼儿园SY的儿童分离的肺炎链球菌青霉素耐药率31.8%,远高于平均水平,该园21株青霉素耐药菌株中20株属于PFGE谱型A或B。结论 上海5所幼儿园健康儿童肺炎链球菌携带株青霉素耐药率总体尚较低。但个别幼儿园具有较高耐药率,可能与青霉素耐药克隆的流行有关。     

High prevalence of antibiotic resistance in nasopharyngeal bacterial isolates from healthy children in rural Uganda: A cross-sectional study

Background: In Uganda, the main causes of death in children under 5 years of age are malaria and pneumonia—often due to delayed diagnosis and treatment. In preparation for a community case management intervention for pneumonia and malaria, the bacterial composition of the nasopharyngeal flora and its in vitro resistance were determined in children aged five or under to establish baseline resistance to commonly used antibiotics.Methods: In a population-based survey in April 2008, nasopharyngeal specimens were collected from 152 randomly selected healthy children under 5 years of age in the Iganga/Mayuge Health and Demographic Surveillance Site (HDSS). Medical history and prior treatment were recorded. Demographic characteristics and risk factors for carriage of resistant strains were obtained from the HDSS census. Bacteria were isolated and analysed for antibiotic susceptibility using disk diffusion and E test.Results: Streptococcus pneumoniae (S. pneumoniae) carriage was 58.6%, and, while most (80.9%) isolates had intermediate resistance to penicillin, none was highly resistant. Whereas no isolate was resistant to erythromycin, 98.9% were resistant to trimethoprim-sulphamethoxazole (co-trimoxazole).Conclusions: In vitro resistance in S. pneumoniae to co-trimoxazole treatment was high, and the majority of isolates had intermediate resistance to penicillin. To inform treatment policies on the clinical efficacy of current treatment protocols for pneumonia in health facilities and at the community level, routine surveillance of resistance in pneumonia pathogens is needed as well as research on treatment efficacy in cases with resistant strains. Improved clinical algorithms and diagnostics for pneumonia should be developed.