首都儿科研究所附属儿童医院门诊感染性腹泻患儿的细菌病原学分析

Analysis of bacterial etiology of the outpatients with infectious diarrhea in the Children′s Hospital Capital Institute of Pediatrics

目的分析首都儿科研究所附属儿童医院门诊感染性腹泻患儿的细菌病原学及其耐药性情况。方法随机选取2017年8月至2018年7月我院门诊诊断为急性感染性腹泻的患儿进行粪便细菌培养,沙门菌血清学分型,PCR方法对5种致泻性大肠埃希菌分型,Kirby-Bauer纸片扩散法检测药物敏感性,统计学分析采用χ^2检验或Fisher确切概率法。结果 356份粪便标本检出致病细菌6种共103株(4份标本同时检出2种细菌),阳性率27.8%(99/356)。沙门菌检出率最高,为10.7%(38/356),其次为金黄色葡萄球菌、致泻性大肠埃希菌与铜绿假单胞菌,检出率分别为8.4%(30/356)、5.6%(20/356)、3.7%(13/356),未检出志贺菌。38株沙门菌血清型以肠炎沙门菌与鼠伤寒沙门菌为主,占63.2%(24/38);20株致泻性大肠埃希菌为肠致病型大肠埃希菌与肠聚集型大肠埃希菌,各10株,未检出肠出血型大肠埃希菌、肠侵袭型大肠埃希菌与肠毒素型大肠埃希菌。沙门菌对氨苄西林、头孢曲松的耐药率分别为52.6%(20/38)、13.2%(5/38);致泻性大肠埃希菌对氨苄西林、头孢曲松的耐药率分别为11/20、1/20,3株致泻性大肠埃希菌产超广谱β内酰胺酶。结论我院门诊感染性腹泻患儿的细菌病原菌以沙门菌为主,金黄色葡萄球菌、致泻性大肠埃希菌、铜绿假单胞菌感染机率增加,志贺菌已不是主要致病菌。沙门菌与致泻性大肠埃希菌对氨苄西林耐药率较高,对头孢曲松普遍敏感,在无法获得病原诊断的情况下可考虑首选三代头孢类药物治疗儿童细菌性腹泻。

Objective To analyze the bacterial etiology and drug resistance of pathogens from the outpatients with acute infectious diarrhea in the Children′s Hospital Capital Institute of Pediatrics. Methods The children with acute infectious diarrhea in the outpatient department of our hospital were randomly enrolled in the period of August 2017 to July 2018. Enteric pathogenic bacteria were cultured and isolated from the fresh stool specimens. The serum of Salmonella spp were identified while five types of diarrheagenic Escherichia coli were detected by PCR method. Antibiotic susceptibility of Salmonella spp and diarrheagenic Escherichia coli were tested by Kirby-Bauer disk diffusion method.Chi-square or Fisher exact test was done for statistical analysis. Results Of the 356 stool specimens, 103 strains of 6 pathogenic bacterial species were detected. The positive rate was 27.8%(99/356), and 2 strains were detected in four stool samples. The isolation rate of Salmonella spp, which was the highest in this study, was 10.7%(38/356). The isolation rate of Staphylococcus aureus, diarrheagenic Escherichia coli and Pseudomonas aeruginosa were 8.4%(30/356), 5.6%(20/356) and 3.7%(13/356), respectively. No Shigella spp strain was isolated. Salmonella enteritidis and Salmonella typhimurium were the dominant serotype for 38 Salmonella spp stains with the isolation rate of 63.2%(24/38). Each 10 Enteropathogenic Escherichia coli and 10 Enteroaggregative Escherichia coli isolates were detected among the diarrheagenic Escherichia coli. Enterohemorrhagic Escherichia coli, Enteroinvasive Escherichia coli and Enterotoxigenic Escherichia colistrain was not found in this study. The resistant rates of Salmonella spp to ampicillin and ceftriaxone were 52.6%(20/38) and 13.2%(5/38), while the diarrheagenic Escherichia coli were 11/20 and 1/20, respectively. Three diarrheagenic Escherichia coli isolates produced extended spectrum beta-lactamase. Conclusions Salmonella spp was the major bacterial pathogen among the outpatients with infectious diarrhea in the hospital. The study indicated that the infection ratios of Staphylococcus aureus, diarrheagenic Escherichia coli and Pseudomonas aeruginosa increased. Shigella spp was no long the main pathogenic agent. The resistant rates of Salmonella spp and diarrheagenic Escherichia coli to ampicillin were high, but low resistant rates to ceftriaxone were found among these two kinds of bacteria. The third-generation cephalosporins should be the first choice for the treatment of childhood bacterial diarrhea.