儿童呼吸道卡他莫拉菌感染的防治

目的探讨卡他莫拉菌感染的初步防治.方法对2001年11月～2003年3月间,在金昌市区3家医院门诊及住院的6岁以下儿童,有呼吸道感染症状者,采集咽部分泌物及痰进行培养,观察并总结其呼吸道卡他莫拉菌感染的情况及临床特点.结果从呼吸道感染病人标本中培养出420株菌.其中,卡他莫拉菌128例,占30.5%,位于第1位,此菌感染多见于体质差的3岁以下儿童,以下呼吸道感染为多见,旦临床表现重,普遍对β-内酰胺类药物耐药.结论积极防治儿童营养性疾病,合理应用抗生素,对3岁以内儿童呼吸系统感染,临床表现重的应及时采集咽部分泌物及痰进行培养,一旦培养出卡他莫拉菌,就应选特效的β-内酰胺酶稳定剂药物治疗.     

肺炎支原体肺炎患儿口咽部常见细菌及临床意义北大核心CSCD

目的:了解肺炎支原体肺炎(MPP)患儿口咽部常见细菌及临床意义。方法:回顾性分析。选取中国医科大学附属盛京医院小儿呼吸内科2016年12月至2017年6月住院治疗的134例MPP患儿为研究对象,选取同期同医院42例健康儿童为健康对照组。采用荧光定量聚合酶链反应Taqman探针法检测入组儿童口咽部常见细菌[肺炎链球菌(SP)、卡他莫拉杆菌(CTA)、流感嗜血杆菌(HI)]。首先比较MPP患儿及健康儿童口咽部细菌检出情况,再将134例MPP患儿根据年龄(<1岁、1~<3岁、3~<6岁及6~14岁)、有无细菌检出[肺炎支原体(MP)、MP+细菌]及检出菌种不同(MP+SP、MP+CTA及MP+HI)进行分组比较。采用秩和检验及 χ^(2)检验对相关临床资料进行分析。 结果:134例MPP患儿检出细菌79例(58.96%),42例健康儿童检出细菌17例(40.48%),差异有统计学意义( χ^(2)=4.404, P<0.05)。与MP组相比,MP+细菌组外周血中白细胞(WBC)水平[8.5(6.7,12.0)×10^(9)/L比7.8(5.8,9.3)×10^(9)/L, Z=-2.232]、C反应蛋白(CRP)水平[19.2(7.2,35.0) mg/L比8.4(3.4,24.6) mg/L, Z=-2.810]、乳酸脱氢酶(LDH)水平[286(244,365) U/L比250(210,302) U/L, Z=-2.474]及大叶性肺炎比例[40.51%(32/79例)比18.18%(10/55例), χ^(2)=7.510]、胸腔积液比例[13.92%(11/79例)比3.64%(2/55例), χ^(2)=3.917]、难治性肺炎支原体肺炎(RMPP)比例[34.18%(27/79例)比18.18%(10/55例), χ^(2)=4.151]均较高;总热程[10(7,12) d比8(6,10) d, Z=-2.706]及抗生素使用时间[16(13,19) d比12(9,16) d, Z=-3.747]均较长,差异均有统计学意义(均 P<0.05)。MP+SP组外周血中WBC高于MP+HI组[12.20(7.80,17.30)×10^(9)/L比6.75(5.37,9.44)×10^(9)/L],差异有统计学意义( Z=11.574, P<0.05);MP+SP组[56.67%(17/30例)]大叶性肺炎发生率高于MP+CTA组[0(0/3例)]和MP+HI组[18.75%(3/16例)],差异有统计学意义( χ^(2)=9.770, P<0.05)。 结论:MPP患儿口咽部更易发生细菌定植或感染,当WBC、CRP及LDH均明显升高,影像表现为大片实变影或有胸腔积液时,提示可能混合细菌感染,热程更长,难治性MPP比例增高,且常见的混合细菌为SP。     

Susceptibility of clinical Moraxella catarrhalis isolates in British Columbia to six empirically prescribed antibiotic agents

BACKGROUND:

Moraxella catarrhalis is a commensal organism of the respiratory tract that has emerged as an important pathogen for a variety of upper and lower respiratory tract infections including otitis media and acute exacerbations of chronic bronchitis. Susceptibility testing of M catarrhalis is not routinely performed in most diagnostic laboratories; rather, a comment predicting susceptibility based on the literature is attached to the report. The most recent Canadian report on M catarrhalis antimicrobial susceptibility was published in 2003; therefore, a new study at this time was of interest and importance.

OBJECTIVE:

To determine the susceptibility of M catarrhalis isolates from British Columbia to amoxicillin-clavulanate, doxycycline, clarithromycin, cefuroxime, levofloxacin and trimethoprimsulfamethoxazole.

METHODS:

A total of 117 clinical M catarrhalis isolates were isolated and tested from five Interior hospitals and two private laboratory centres in British Columbia between January and December 2012. Antibiotic susceptibility of M catarrhalis isolates was characterized using the Etest (E-strip; bioMérieux, USA) according to Clinical Laboratory Standards Institute guidelines.

RESULTS:

All isolates were sensitive to amoxicillin-clavulanate, doxycycline, clarithromycin, levofloxacin and trimethoprimsulfamethoxazole. One isolate was intermediately resistant to cefuroxime, representing a 99.15% sensitivity rate to the cephem agent. Cefuroxime minimum inhibitory concentrations (MICs) inhibiting 50% and 90% of organisms (MIC50 and MIC90) were highest among the antibiotics tested, and the MIC90 (3 μg/mL) of cefuroxime reached the Clinical Laboratory Standards Institute breakpoint of susceptibility.

DISCUSSION:

The antibiotic susceptibility of M catarrhalis isolates evaluated in the present study largely confirms the findings of previous surveillance studies performed in Canada. Cefuroxime MICs are in the high end of the sensitive range and the MIC50 and MIC90 observed in the present study are the highest ever reported in Canada.

CONCLUSION:

Although cefuroxime MICs in M catarrhalis are high, all agents tested showed antimicrobial activity, supporting their continued therapeutic and empirical use.     

湖南儿童抗生素使用前呼吸道感染的细菌病原学分析

[目的]了解湖南地区儿童抗生素使用前呼吸道感染的细菌分布特点,为本地区儿童呼吸道感染的临床诊疗提供病原学依据.[方法]以2012年3月到2014年12月在湖南长沙、湘潭、岳阳、常德、衡阳、邵阳以及郴州等12个哨点单位因急性呼吸道感染就诊且未使用抗生素的患儿为研究对象,采集鼻咽拭子标本进行细菌培养,结合临床资料进行统计分析.[结果]886例细菌检测样本中培养阳性188例(21.22％),其中以肺炎链球菌(8.24％)、卡他莫拉菌(3.05％)、流感嗜血杆菌(2.60％)多见.不同年龄组中,≤6个月组细菌检出率高于其他4组,差异有统计学意义;不同季节细菌检出率差异有统计学意义,以春季检出率最高,夏季最低.样本送检时间对细菌培养阳性率有一定影响,但无统计学差异.[结论]湖南地区儿童抗生素使用前呼吸道感染的最常见细菌为肺炎链球菌,其次为卡他莫拉菌、流感嗜血杆菌.各种细菌在不同年龄、季节阳性检出率有差异.样本送检时间对细菌检出率无显著影响.     

小儿下呼吸道感染中卡他莫拉菌的分离特点与耐药性分析

目的 了解小儿卡他莫拉菌感染的临床特点、耐药性及预后,指导合理用药.方法 对重庆市儿童医院10 442 例下呼吸道感染(lower respiratory infection, LRI)患儿进行痰培养;对分离出的卡他莫拉菌行药敏试验及β-内酰胺酶检测,并分析其临床特点与预后;同时检测其他呼吸道病原.结果 卡他莫拉菌感染多见于婴幼儿,常见合并其他病原感染;该菌冬季分离率最高;β-内酰胺酶阳性率为63.4%,其中对氨苄西林及复方新诺明的耐药率分别为46.2%和43.4%,对头孢类及含酶抑制剂的抗生素耐药率不超过5.0%;临床治疗较顺利.结论 小儿LRI中卡他莫拉菌的感染与年龄、季节有关,产β-内酰胺酶率较低,对氨苄西林的耐药率居第一,应对其耐药性及产酶率进行连续监测,提供合理用药依据.     

Airway microbiota and acute respiratory infection in children

Acute respiratory infections (ARIs), such as bronchiolitis and pneumonia, are the leading cause of hospitalization of infants in the US. While the incidence and severity of ARI can vary widely among children, the reasons for these differences are not fully explained by traditional risk factors (e.g., prematurity, viral pathogens). The recent advent of molecular diagnostic techniques has revealed the presence of highly functional communities of microbes inhabiting the human body (i.e., microbiota) that appear to influence development of local and systemic immune response. We propose a ‘risk and resilience’ model in which airway microbiota are associated with an increased (risk microbiota) or decreased (resilience microbiota) incidence and severity of ARI in children. We also propose that modulating airway microbiota (e.g., from risk to resilience microbiota) during early childhood will optimize airway immunity and, thereby, decrease ARI incidence and severity in children.     

Role of Moraxella (Branhamella) catarrhalis as a respiratory pathogen in children

During a 12-month surveillance period in 1981-1982, Moraxella catarrhalis was detected in cultures from nasopharyngeal aspirates from 76 (17%) of 449 children hospitalized with middle or lower respiratory tract infection. Seroconversion to M. catarrhalis was positive in 4(5%) of the 76 patients with M. catarrhalis present in nasopharyngeal aspirates and in 4(1%) of 373 patients with a negative finding. Although children with respiratory tract infections were often colonized by the organism, this was rarely the infective agent of the middle or lower airways. Four of 8 patients with seroconversion to M. catarrhalis exhibited a concomitant RSV infection. The carriage of this species was more closely associated with parainfluenza virus infections. Serological responses to M. catarrhalis were not associated with acute otitis media, and were also rare in children with pneumonia. It is concluded that bronchopulmonary infections caused by M. catarrhalis are rare in children, and that M. catarrhalis aetiology need not be considered in the selection of antibiotics in cases of community-acquired pneumonia or other infections of the middle or lower respiratory tract affecting primarily healthy children.     

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     

Detection rates of bacteria in chronic otitis media with effusion in children

This study was performed to investigate polymerase chain reaction-based detection of bacterial DNA in middle ear fluid and assess the correlation between the PCR-positive rate with several factors associated with middle ear effusion. The purpose was to gain a further understanding of bacterial infection as a major cause of otitis media with effusion. Of the 278 specimens of middle ear fluid, 39 (14%) tested positive by ordinary culture. The overall detection rate of bacterial DNA using the PCR method was 36.7% for middle ear effusion, and bacterial DNA detection rates of Hemophilus influenzae, Streptococcus pneumoniae, Moraxella catarrhalis in the middle ear effusion were 29.1%, 4.7% and 10.8%, respectively. The bacterial DNA detection rate was higher in ears with a history of acute otitis media than those without the history. High detection rates were observed in patients younger than 48 months who have had a higher tendency to present with acute otitis media. We concluded that PCR is a more sensitive method for the detection of bacteria in middle ear effusion than ordinary culture, and acute otitis media is a major contributor to the pathogenesis of otitis media with effusion.