先天性心脏病并下呼吸道感染患儿病原学及细菌耐药性分析

目的了解先天性心脏病(CHD)并下呼吸道感染的病原学组成及细菌耐药情况,以指导临床治疗。方法回顾性分析2006年8月-2011年3月本科收治的156例CHD并下呼吸道感染患儿的鼻咽分泌物病毒、细菌检测结果和药敏试验报告。采用直接免疫荧光法检测呼吸道合胞病毒、副流感病毒3等7种常见呼吸道病毒,K-B法进行细菌药敏试验。结果 156例CHD并下呼吸道感染患儿中,病毒感染29例(18.6%),以呼吸道合胞病毒(14.7%)为主;细菌感染97例(62.2%),以革兰阴性杆菌为主,前3位细菌依次为肺炎克雷伯菌(19.9%)、大肠埃希菌(17.9%)和肺炎链球菌(7.7%);检出真菌(白色假丝酵母菌)7例(4.5%);混合感染36例(23.1%)。肺炎克雷伯菌和大肠埃希菌产超广谱β内酰胺酶(ESBLs)阳性菌株合计检出率为23.7%;肺炎克雷伯菌和大肠埃希菌对氨苄西林的耐药率分别达100%和96.4%,对头孢类抗生素耐药率达50.0%以上,而对头孢哌酮/舒巴坦、哌拉西林/他唑巴坦有效,对亚胺培南高度敏感;肺炎链球菌对氨苄西林、红霉素耐药率达60.0%以上,对头孢类抗生素有效,对亚胺培南、万古霉素高度敏感。结论 CHD并下呼吸道感染患儿的主要病原为细菌,以革兰阴性杆菌为主,混合感染多见,并检出有真菌,主要细菌的耐药性及革兰阴性杆菌产ESBLs率均较高。应加强CHD下呼吸道感染病原学检测,以指导合理用药,减少耐药菌株的产生和真菌感染的发生。

Analysis of Pathogens and Drug Resistance in Children with Congenital Heart Disease Complicated with Lower Respiratory Tract Infection

Objective To analyze the pathogen spectrum and the characteristics of antibiotic resistance in children with congenital heart disease(CHD) complicated with lower respiratory tract infection so as to provide some references for clinical work. Methods A total of 156 CHD children complicated with lower respiratory tract infection,admitted from Aug.2006 to Mar.2011,were detected for pathogens of their nasopharyngeal secretions and(or) sputum.Antimicrobial susceptibility was tested by disc diffusion(K-B) method.Direct immunofluorescence assay was used to detect the respiratory syncytial virus,adenovirus,influenza virus A and B,parainfluenza virus type 1,2,3.The data were retrospectively analyzed. Results Of the 156 cases,29 cases(18.6%) were infected with virus,with respiratory syncytial viruses(RSV) being the dominant pathogen(14.7%),97 cases were infected with bacterial,Gram-negative bacillus being the principal pathogen and the top three pathogenic bacteria being klebsiella pneumoniae(K.pn,19.9%),Escherichia coli(E.coli,17.9%)and streptococcus pneumoniae(SP,7.7%).There were 7 cases(4.5%) being Fungi(candida Albicans) positive.Thirty-six cases had mixed infections(23.1%).Extended spectrum beta-lactamases(ESBLs)-producing K.pn and E.coli accounted for 23.7% of all bacterial infections.The resistance rates of K.pn and E.coli to ampicillin were 100% and 96.4% respectively,while to cephem antibiotics,more than 50%.However,K.pn and E.coli were relatively sensitive to cefoperazone/sulbactam and piperacillin/tazobactam,and were highly sensitive to imipenem.The resistance rates of SP to penbritin and erythromycin were more than 60.0%.However,SP was sensitive to cephem antibiotics,and were highly sensitive to imipenem and vancomycin. Conclusions Bacteria,especially Gram-negative bacillus,were the most common pathogens of CHD children complicated with lower respiratory tract infection.Mixed infections were a commonplace.Fungi were isolated in several cases.Both antibiotic resistance rates of the common bacteria and ESBLs-producing rates of Gram-negative bacillus were rather high.Etiological examination is essential in rational use of antibiotics and reducing fungal infection as well as the emergence of drug-resistant bacterial strains,and therefore should be promoted in CHD children complicated with lower respiratory tract infection.