分子生物学方法在新生儿肺炎死亡病例大肠埃希菌的检测应用

Detection and application of Escherichia coli in dead cases of neonatal pneumonia with molecular biology methods

目的探讨新生儿重症肺炎死亡病例中大肠埃希菌(E.coli)感染的地位。方法收集北京儿童医院新生儿重症肺炎组200例和非感染性疾病(对照组)34例的尸检病理标本,应用PCR和Southern blot技术检测E.coli特异性uidA基因片断,并复习患儿临床资料。结果肺炎组中,PCR和Southern blot对E.coli检出率明显高于对照组(PCR:5.0% vs. 0,掊2=11.37,P<0.01;Southern blot:21.5% vs. 5.9%,掊2=4.56,P<0.05);晚发型肺炎E.coli检出率明显高于早发型(PCR:8.2%vs.1.9%,掊2=4.18,P<0.05;Southern blot:26.8% vs. 16.5%,掊2=4.48,P<0.05)。1980年前E.coli检出率高于1981年后(Southern blot法:28.0%vs.15.0%,掊2=5.00,P<0.05)。E.coli检测阳性组和阴性组比较,临床表现的差异无统计学意义(P﹥0.05)。结论 E.coli是新生儿重症肺炎死亡病例中的重要病原。分子生物学方法检测E.coli对早期诊断有重要价值。

Objective To study the status of Escherichia coli（E.coli） infection in dead cases of neonatal pneumonia in Beijing Children＇s Hospital.Methods Autopsy pathological specimens were collected from 200 cases of dead neonatal pneumonia and 34 cases of dead neonatal without infectious diseases.PCR and Southern blot were applied to detect E.coli specific uidA gene target sequence.The clinical data of these cases were reviewed as well.Results The positive rate of E.coli in the study group was significantly higher than that in the control group with PCR and Southern blot（PCR：5% vs.0,x2=11.37,P 〈0.01.Southern blot：21.5% vs.5.9%,x2=4.56,P 〈0.05）.The positive rate of E.coli in late-onset cases was significantly higher than that in early onset cases（PCR：8.2% vs.1.9%,x2=4.18,P 〈0.05.Southern blot：26.8% vs.16.5%,x2=4.48,P 〈0.05）.The positive rate of E.coli in cases before 1980 was significantly higher than that after 1981（Southern blot：28.0% vs.15%,x2=5.00,P 〈0.05）.There were no significant differences between the E.coli positive cases and negative cases in clinical manifestation.Conclusion E.coli is an important pathogen in dead cases of neonatal pneumonia in Beijing Children＇s Hospital.Molecular biological method has important value on early diagnosis of E.coli infection.