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。     

儿童呼吸道卡他莫拉菌分离株耐药性与BRO基因分型研究

目的调查儿童呼吸道卡他莫拉菌分离株产β内酰胺酶情况和耐药性,以及菌株BRO酶基因特征。方法2011年6月至2012年9月,从儿童呼吸道分离卡他莫拉菌401株;用微量肉汤稀释法测定常用抗生素最低抑菌浓度,用Nitroceifn纸片法检测β-内酰胺酶,用PCR扩增结合限制性内切酶分析方法对分离株进行BRO基因分型。结果401株卡他莫拉菌的β-内酰胺酶产酶率为96.5%（387/401）;产酶株对氨苄西林、头孢克洛、头孢呋辛的MIC50、MIC90和耐药率明显高于非产酶株,差异有统计学意义（P<0.05）;产酶株BRO基因阳性率为99.2%（384/387）,其中BRO-1型为93.0%,BRO-2型为7.0%;BRO-1+菌株对氨苄西林、头孢克洛、头孢呋辛和阿齐霉素的MIC50和MIC90明显高于BRO-2+菌株。结论儿童呼吸道卡他莫拉菌分离株β-内酰胺酶产酶率高,产酶株主要携带BRO-1基因,其对部分β-内酰胺类和大环内酯类抗生素的影响明显高于BRO-2型菌株。     

卡他莫拉菌研究进展

卡他莫拉菌是儿童上颌窦炎、中耳炎、肺炎等呼吸道感染的第3位常见致病菌,仅次于流感嗜血杆菌和肺炎链球菌,目前产酶耐药株比例已超过90%.卡他莫拉菌通过产生BRO 内酰胺酶对青霉素耐药.卡他莫拉菌产生的内酰胺酶分为BRO-1、BRO-2及BRO-3,由染色体基因编码,而且编码基因较易在细菌间转移.与其他已知β内酰胺酶不同,BRO基因是卡他莫拉菌新近获取的外源基因,21个新突变发生于BRO基因的启动子.     

2004年肺炎链球菌、流感嗜血杆菌和卡他莫拉菌耐药监测

目的监测2004年呼吸道常见致病菌肺炎链球菌、流感嗜血杆菌和卡他莫拉菌对抗生素的耐药性。方法抗生素药敏试验采用E_test法和K_B法。结果肺炎链球菌对青霉素不敏感率为32.9%,对头孢克洛、头孢呋辛和头孢曲松分别为25.0%、26.4%和5.7%,对红霉素、阿齐霉素和克林霉素不敏感率>90%;流感嗜血杆菌和卡他莫拉菌对氨苄青霉素耐药率分别为14.3%和56.6%,但前者β_内酰胺酶阳性率为14.3%,而后者为90.8%,两者对其他β_内酰胺酶类耐药率较低。结论呼吸道致病菌对抗生素的耐药性正在增加,连续监测抗生素的耐药性对经验治疗呼吸道感染非常必要。     

呼吸道感染儿童鼻咽分泌物卡他莫拉菌的耐药情况

目的 研究近年来儿童呼吸道感染常见致病菌卡他莫拉菌的耐药情况.方法 取2004-2006年首都医科大学附属北京友谊医院门诊及住院145例呼吸道感染患儿鼻咽分泌物分离的11株卡他莫拉菌(根据菌落形态、革兰染色及生化鉴定确定),分离株取自上呼吸道感染5例,支气管炎、肺炎各3例.采用琼脂稀释法进行抗生素最小抑菌质量浓度(MIC)测定(抗生素标准品包括氨苄西林、头孢拉定、头孢呋辛、头孢曲松、青霉素、红霉素、罗红霉素和阿奇霉素),并用Cefinase纸片进行β-内酰胺酶检测.采用WHONET 5和SPSS 11.5软件进行药敏分析.结果 11株卡他莫拉菌中10株为β-内酰胺酶阳性株.对氨苄西林、头孢呋辛及红霉素的耐药率分别为81.8%、63.6%和18.2%,对头孢曲松100%敏感;对青霉素及头孢拉定的能抑制90%被试菌株的MIC(MIC90)分别为32.0 mg/L和8.0 mg/L,对罗红霉素和阿奇霉素的MIC90分别为2.0 mg/L和0.25 mg/L.结论 卡他莫拉菌为条件致病菌,该菌产酶率高,对青霉素、氨苄西林、1代头孢菌素及2代头孢菌素均有较高耐药率,对头孢曲松敏感.应引起重视,并加强对该菌的耐药性监测.     

儿童呼吸道感染时3种病原菌检出率及耐药性观察

目的 了解儿童呼吸道感染时嗜血杆菌属、卡他莫拉氏菌、肺炎链球菌检出率及耐药性。方法 对我院2002年6～12月504例因急性呼吸道感染住院患儿，用低压吸引器接一次性吸痰管吸取患儿咽喉部痰液进行培养，采用法国生物梅里埃公司药敏纸片K—B法进行药敏试验。结果 检出3种病原菌224株，检出率44．4％，嗜血杆菌、卡他莫拉氏菌、肺炎链球菌检出率分别为19．2％、13．5％、11．7％，占所有检出菌的前3位；嗜血杆菌属对环丙沙星、阿奇霉素、氨曲南、亚胺培南等敏感，对头孢类抗生素耐药率为头孢曲松7．2％、头孢呋辛5．2％、头孢噻肟6．2％、头孢克洛12．4％，磺胺类药物高度耐药(64．9％)；卡他莫拉氏菌对环丙沙星、阿奇霉素、亚胺培南等敏感，对头孢类抗生素耐药率为头孢曲松20．6％、头孢呋辛5．9％、头孢噻肟5．9％、头孢克洛8．8％，磺胺类药物耐药29．4％；肺炎链球菌对万古霉素100．0％敏感，对氧氟沙星敏感率为85．4％，对四环素、磺胺类、红霉素等高度耐药，耐药率分别为76．7％、89．9％、96．6％。结论 本地区儿童呼吸道感染以嗜血杆菌属、卡他莫拉氏菌、肺炎链球菌感染率较高，临床治疗应根据药敏指导合理使用抗生素。     

儿童携带卡他莫拉菌的耐药性及bro基因分型研究

目的对儿童携带214株卡他莫拉菌分离株产酶率和9种抗生素敏感性测定,研究产酶株β-内酰胺酶耐药基因特征。方法采用英国抗生素化疗学会(BSCA)琼脂稀释法进行抗生素最小抑菌浓度测定;用Nitrocefin纸片琼脂扩散法检测β- 内酰胺酶;PCR扩增结合限制性内切酶分析方法对分离株进行bro基因分型。结果214株卡他莫拉菌中β-内酰胺酶产酶率为94.4%。产酶株对β-内酰胺类抗生素:氨苄西林、头孢呋辛、头孢克洛的MlC90分别为32 mg/L、2 mg/L和8 nag/L,明显高于非产酶株的0.5 mg/L,10 mg/L和0.5 mg/L;产酶株对氨苄西林、头孢呋辛、头孢克洛耐药率分别为95%、46.5%和76 2%,明显高于非产酶株组(0%)(x2=100.889,8.159,28.961 P均<0 001);产酶株与非产酶株组对头孢噻肟、非β-内酰胺类抗生素红霉素、环丙沙星、氯霉素和四环素敏感性无显著差异,其总体敏感性分别为100%、95.8%、100%、100%、34.1%,所有分离株对复方磺胺甲(口恶)唑产生耐药(100%),MIC50和MIC90高达32 mg/L和128 mg/L。202例产酶株经bro基因分型,69.8%(141/ 202)为bro—Ⅰ型,30.2%(61/202)为bro-Ⅱ型。bro-Ⅰ型携带菌株对β-内酰胺类抗生素的MIC50和MIC90高于bro-Ⅱ型的耐药株。结论北京地区携带的卡他莫拉菌β-内酰胺酶产酶率较高,产酶株对氨苄西林耐药较为     

卡他莫拉菌研究进展

卡他莫拉菌的菌体结构较简单,存活力较强,近年发现它在呼吸系统感染中占越来越重要的地位。该菌的分离率不断增加,其携带和感染与年龄及季节有关,而且存在地区差异。由于该菌产β内酰胺酶率的增高,对β内酰胺类抗生素的耐药率也逐渐增加。目前尚无卡他莫拉菌的疫苗。因此国外对其免疫学的研究较多,但仍仅限于动物实验。该文就卡他莫拉菌的生物学特性、感染、耐药及其机制和免疫学进展进行综述。     

重庆地区肺炎儿童下呼吸道卡他莫拉菌分离株耐药基因研究

目的探讨重庆地区儿童卡他莫拉菌(Moraxella catarrhalis,Mc)分离株对β-内酰胺类抗生素的耐药机制,指导临床合理用药,有利于防止诱导该菌耐药性变迁。方法取2006年6—12月住院的肺炎患儿下呼吸道中分离的β-内酰胺酶阳性Mc40株,采用PCR技术扩增其基因组DNA,经限制性内切酶酶切后,行琼脂糖凝胶电泳,分析Mc的耐药基因表达及分型,同时比较不同基因型的临床特点。结果40株β-内酰胺酶阳性卡他莫拉菌的BRO基因型为:36株(90.0%)BRO-1基因阳性,3株(7.5%)BRO-2基因阳性,1株(2.5%)未检测到BRO-1基因和BRO-2基因。BRO-1基因阳性菌对多数β-内酰胺类抗生素的抑菌圈直径小于BRO-2基因阳性菌株。结论重庆地区儿童Mc的产酶株以BRO-1基因为主,少数为BRO-2基因,极少菌株可能为其他型别。     

1?082例呼吸道感染住院患儿鼻咽部携带卡他莫拉菌状况及其耐药性分析

目的了解呼吸道感染儿童鼻咽部卡他莫拉菌的携带情况及分离株对常见抗菌药物的敏感性。方法采集1 082例呼吸道感染患儿鼻咽拭子并分离卡他莫拉菌,采用E-test法和纸片扩散法检测菌株对11种常见抗菌药物的敏感性,结合3种判读标准解读检测结果。用头孢硝噻吩纸片法检测分离株是否产β-内酰胺酶。结果 1 082例呼吸道感染患儿中,鼻咽部卡他莫拉菌携带率为7.12%(77/1 082)。所有菌株均产β-内酰胺酶。无论使用哪种判读标准,所有菌株对阿莫西林-克拉维酸均敏感;对环丙沙星和四环素的敏感率95.0%。根据EUCAST和CLSI标准,分离株对磺胺甲噁唑-甲氧苄啶的敏感率高达98.7%,对所检测的3种头孢菌素的敏感率均超过80%。但根据BSAC标准判读时,菌株对头孢呋辛的敏感率仅为2.6%,对氨苄西林耐药率为81.8%。依据CLSI判读时,分离株对红霉素的不敏感率为79.2%,根据EUCAST或BSAC判断时,其不敏感率高达90.9%,且超过三分之一的菌株(27/77,35.1%)MIC值256 mg/L。结论呼吸道感染患儿鼻咽部卡他莫拉菌分离株均产β-内酰胺酶,对阿莫西林-克拉维酸全部敏感,对第三代和第四代头孢菌素、磺胺甲噁唑-甲氧苄啶敏感率高,但多对氨苄青霉素、头孢呋辛和红霉素耐药。     

成都地区儿童金黄色葡萄球菌定植/感染分离株的流行病学研究

目的调查成都地区儿童金黄色葡萄球菌定植/感染分离株的流行病学特征。方法 2004年1月—2009年4月,以成都市健康儿童、门诊呼吸道感染患儿和金黄色葡萄球菌感染住院患儿为研究对象,采集鼻拭子或感染部位标本进行培养,并对分离的金黄色葡萄球菌进行药敏实验,应用PCR方法检测菌株的PVL毒力基因和mecA耐药基因,对菌株进行多位点序列分析(MLST)。结果培养分离金黄色葡萄球菌定植株174株、感染株51株。门诊呼吸道感染患儿金葡菌的多重耐药率分别为,定植株59.3%,感染株52.9%;PVL基因阳性率分别为,定植株55.6%(15/27),感染株80.4%(41/51);mecA耐药基因阳性率分别为,定植株11.1%(3/27),感染株62.7%(32/51)。对健康儿童定植株以及感染株进行MLST分析,共发现33个ST类型,定植株以ST121、ST59和ST398为主,感染株以ST121、ST88和ST398为主;这些菌株属于15个克隆类型,以CC121、CC59和CC398为主。结论成都地区儿童金黄色葡萄球菌定植和感染分离株具有较高的PVL毒力基因和mecA耐药基因携带率,具有明显不同于其他地区的独特的遗传背景。     

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.     

Branhamella catarrhalis in neonatal pulmonary infectious pathology

Bronchopulmonary infections has been described for the most part in adults. ORL and upper respiratory tract infections are encountered in children. In neonates, only conjunctivitis have been reported. In their report, the authors describes the first cases of bronchopulmonary infections due to Branhamella Catarrhalis in premature infants with respiratory distress syndrome. Three cases are described in which this bacteria has been isolated in bronchial secretions and in the culture of the nasotracheal tube. Clinical and biological features were not specific. Only orosomucoid serum level was increased. A favourable outcome was obtained by macrolides. Epidemiological survey permitted the isolation of Branhamella Catarrhalis in one of the nurse who had taken care of the neonates. Otherwise, these infections occurs in immunologically compromised hosts. Hyaline membrane disease appears most likely as an auspicious factor.     

Josamycin in bronchopulmonary and otorhinological diseases in pediatrics

Josamycin, one of the more recent macrolide antibiotics, was evaluated in 29 children aged from 2 months to 13 years with bronchopulmonary or otorhinological disease. With a daily dose in the range 30 to 60 mg/kg bodyweight, and an average treatment period of 7.7 days, 24 children were cured and 5 markedly improved. In only 4 children were minor side effects, such as gastrointestinal disturbances, observed, which in no case necessitated interruption of therapy. By virtue of its spectrum of activity josamycin seems to be an ideal antibiotic for the treatment of bacterial respiratory tract infections. In addition, josamycin displays a high degree of activity against mycoplasmas and chlamydiae. Only a very low percentage, reported as 6%, of staphylococcal are primarily resistant to the antibiotic, and the rapid development of resistance to other macrolides, has not been reported for josamycin. No cross resistance exists between josamycin and penicillins, cephalosporins, tetracycline or aminoglycosides. These characteristics represents josamycin for the treatment of respiratory tract infections. The pleasant taste of the preparation used in this study ensured its ready acceptance by the children treated.     

5岁以下儿童门诊呼吸道感染常见病原携带及抗生素耐药的流行病学特征调查

目的　了解 5岁以下儿童呼吸道感染肺炎链球菌 (SP)、流感嗜血杆菌 (HI)、卡他莫拉菌 (M .Cat)携带株的流行病学特征、耐药情况及其影响因素。方法　对 2 0 0 0年 1月至 2 0 0 3年 5月在北京儿童医院内科门诊就诊的≤ 5岁呼吸道感染儿童进行随机选择问卷调查 ;采鼻咽拭子标本 ;培养、分离、鉴定SP、HI,其中对 2 0 0 2年 1月至 2 0 0 3年 5月的标本同时进行了M .Cat的分离 ;用E test、K B法检测SP、HI对抗生素的敏感性 ,用琼脂扩散法检测M .Cat的药物敏感性 ;评价年龄、居住地、入托、抗生素使用、诊断对病原携带及其耐药株的影响。结果　本文≤ 5岁儿童呼吸道感染SP、HI、M .Cat的携带率分别为 2 8 6%、2 8 3%、1 5 8%。SP青霉素耐药率为 2 3 3% ,HI氨苄青霉素的耐药率为 1 0 2 % ,M .Cat对氨苄青霉素的耐药率高达 90 3%。影响病原携带、抗生素耐药的主要因素有年龄、入托、抗生素使用。结论　≤ 5岁儿童呼吸道感染携带病原菌株耐药率快速上升 ,抗生素使耐药菌株携带率增高 ,因而合理使用抗生素非常重要。     

Antimicrobial susceptibility of Staphylococcus aureus in children with atopic dermatitis

Background: Skin infection and/or nasal carriage of Staphylococcus aureus in children with atopic dermatitis (AD) is a risk factor for exacerbating disease or subsequent recurrent S. aureus infection. The purpose of the study is to evaluate the antibiotic susceptibilities of S. aureus strains from AD children and determine the most appropriate choice of antibiotics. Methods: Nasal swabs from 168 healthy children with AD and 20 AD children with concurrent skin and soft‐tissue infections (SSTI) were collected in 2005–2008. S. aureus strains were further analyzed for and compared with antibiotic susceptibilities. Results: There were 78 (46.4%) healthy children with AD colonized with S. aureus, and 24 (30.8%) were methicillin‐resistant S. aureus (MRSA). Among the 20 SSTI‐infecting strains, 12 (60%) were MRSA. Antimicrobial susceptibility testing showed that, after penicillin, colonizing and SSTI‐infecting strains had the highest rates of resistance to erythromycin (50% and 70%, respectively). All isolated strains were susceptible to vancomycin, rifampin, and mupirocin. Multi‐drug resistance was found in 70% of the colonizing and 50% of the SSTI‐infecting strains. D‐test assay revealed inducible clindamycin resistance in 75% of the colonizing strains. The most prevalent resistance gene was ermB which was present in 94.9% and 92.9% of colonizing and SSTI‐infecting strains, respectively. Conclusions: This study found that colonizing and SSTI‐infecting strains of S. aureus from AD children had a high prevalence of MRSA and multi‐drug resistance. Trimethoprim‐sulfamethoxazole, rifampin, fusidic acid and mupirocin appear to be more suitable for treatment and decolonization of S. aureus in AD children.     

Antimicrobial resistance among pediatric respiratory tract infections: clinical challenges

Considerable development of antimicrobial resistance has occurred in the major pediatric bacterial pathogens, Streptococcus pneumoniae, Haemophilus influenzae, and Moraxella catarrhalis. However, most of the respiratory infections that children suffer are viral and self-limiting, and only a small percentage of them will develop secondary bacterial infections with the pathogens listed. The challenge for rational antibiotic use is to determine which patients can be treated conservatively and which require antimicrobial intervention to avoid prolonged discomfort or development of permanent sequelae. The basis for rational use of antibiotic in the era of resistance in these major pathogens is to avoid overuse of antimicrobial agents, tailor treatment to identified pathogens as much as possible, and base empiric treatment on the disease being treated and the susceptibility of the probable pathogens at breakpoints based on pharmacokinetic and pharmacodynamic parameters. With appropriate dosing regimens based on these parameters and despite development of resistance, amoxicillin is still one of the most active oral agents against S. pneumoniae and non-beta-lactamase producing strains of H. influenzae, whereas amoxicillin-clavulanate is active against beta-lactamase-producing strains of H. influenzae and M. catarrhalis. Parenteral ceftriaxone and oral and parenteral fluoroquinolones are active against all 3 species, but fluoroquinolones should be used with utmost caution when all other options have been considered because of concerns about toxicity and development of resistance. Introduction of a 7-valent conjugate pneumococcal vaccine in the United States in 2000 reduced the prevalence of invasive pneumococcal disease in children younger than 2 years old, but, as of 2001, had not had a major impact on decreasing antimicrobial resistance.     

Colonizing and invasive strains of Streptococcus pneumoniae in Uruguayan children: type distribution and patterns of antibiotic resistance.

For the first time in Uruguay the frequency of moderate to heavy colonization of the upper respiratory tract by Streptococcus pneumoniae was investigated in children with acute respiratory infections (n = 717) and in healthy controls (n = 564). Serotypes of S. pneumoniae were identified as colonizing and invasive strains and their susceptibility to antibiotics was determined. Semiquantitative cultures of nasopharyngeal aspirates yielded 42.1% of positives in ambulatory patients and 15.2% in controls. Throat swabs from hospitalized children and matched controls revealed, respectively, 18.4 and 11.5% colonization. Different sampling and culture procedures were evaluated. Seasonal variations in colonization were also detected. Geographic variations in serotype frequency and distribution were assessed. Serotype 14 was predominant among invasive and colonizing strains in patients. Ten serotypes, included in the 23-valent S. pneumoniae vaccine, were not detected. Intermediate resistance to penicillin was seldom observed, but 37.2% of the invasive strains were resistant to cotrimoxazole, indicating the need for a permanent surveillance of isolates to antibiotic susceptibility.     

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目的调查温州育英儿童医院小儿下呼吸道感染的病原菌及其耐药性。方法对2003-01—2004-12温州医学院附属育英儿童医院呼吸病区1763例下呼吸道感染患儿的痰液标本经分离培养,做菌株鉴定和药敏试验。结果共分离培养出病原菌715株,总阳性率为40·6%。其中革兰阴性菌448株,占62·7%;革兰阳性菌148株,占20·7%;真菌119株,占16·6%。革兰阴性菌以肺炎克雷伯菌、大肠埃希菌、铜绿假单胞菌和鲍曼不动杆菌为主。肺炎克雷伯菌和大肠埃希菌产超广谱β-内酰胺酶(ESBLs)的百分率分别为49·3%和46·5%,较敏感的抗生素为亚胺培南、丁胺卡那霉素、环丙沙星、哌拉西林/他唑巴坦和头孢哌酮/舒巴坦;除铜绿假单胞菌对复方新诺明的耐药率为100%外,铜绿假单胞菌和鲍曼不动杆菌对各种抗生素的耐药性均较低。革兰阳性菌中以肺炎链球菌和金黄色葡萄球菌为主。肺炎链球菌对青霉素的耐药率达到71·1%,对环丙沙星和万古霉素敏感,耐药率为0。金黄色葡萄球菌中耐甲氧西林金葡菌(MRSA)占18·0%(9/50),对环丙沙星、左旋氧氟沙星和万古霉素敏感。结论温州地区小儿下呼吸道感染的病原菌以革兰阴性菌为主,肺炎克雷伯菌、大肠埃希菌、铜绿假单胞菌、鲍曼不动杆菌、肺炎链球菌、金黄色葡萄球菌为主要病原菌。对抗生素的耐药性较强,临床上应注意对这些菌株的检测,积极防治。