产超广谱β-内酰胺酶大肠埃希菌儿童尿路感染临床特点及预测因素分析

Clinical characteristics and predictive factors of urinary tract infection in children caused by extended spectrum β-Lactamases-producing Escherichia coli

目的：总结产超广谱β-内酰胺酶（Extended- Spectrum β- Lactamase，ESBLs）大肠埃希菌儿童尿路感染（Urinary tract infection，UTI）病例的临床特点及相关预测因素,旨在从临床特点中早期识别产ESBLs细菌感染病例，指导经验性治疗。方法收集195例尿培养阳性病例，对其中112例大肠埃希菌感染病例进行回顾性分析，对比产ESBLs组与非产ESBLs组的临床特点，采用χ^2检验及多元逐步logistic回归分析产ESBLs大肠埃希菌感染的预测因素。结果195例中，大肠埃希菌为112例（占57.44%），其中产ESBLs菌株79例（占70.54%）。发病年龄＜2岁、培养前使用抗生素、存在尿路异常者更易致产ESBLs菌株感染，产ESBLs大肠埃希菌感染组年龄更小，培养前使用抗生素及存在尿路异常的比例更高，临床上发热、血CRP值升高的表现更显著，非产ESBLs大肠埃希菌组经验性治疗有效率较高，平均住院日更短（P＜0.05或0.01）。多因素logistic回归分析提示培养前使用抗生素、尿路异常、发热、血CRP升高为产ESBLs菌株感染的预测因素（OR =4.657、2.961、5.721、1.442，P＜0.05）。结论对于年龄＜2岁、发热性尿路感染、存在尿路异常，培养前使用过抗生素，血CRP值较高水平的病例，更有可能提示产ESBLs大肠埃希菌感染，可以选择β-内酰胺酶抑制剂复合物类抗生素或碳青霉烯类抗生素作为经验性治疗药物，而没有这些特点的病例，倾向于非产ESBLs大肠埃希菌感染，头孢三代抗生素可作为选择药物。

Objective To investigate the clinical characteristics and predictive factors of urinary tract infections （UTIs） in children caused by Extended- Spectyumβ- Lactamase （ESBLs）- producing Escherichia coli （E.coli）, and to distinguish cases caused by ESBLs- producing E.coli earlier,and guide the empirical therapy. Methods 195 patients with positive urine culture in our children hospital from January 2011 to December 2012 were included. The clinical characteristics and predictive factors of UTIs caused by ESBLs- producing E.coli were analyzed by Chi- square test and multivariate logistic regression analysis. Results A total of 195 uropathogens were isolated, dominant with E.coli （n=112, 57.44%）, including 79 （70.54%） ESBLs- pro-ducing strains.The patients with younger age （〈2 years old）, urinary tract anomalies, or had the history of antibiotic use be-fore urine culture were more likely be infected with ESBLs- producing E.coli. Compared with non- ESBL UTIs, children with ES-BL UTIs had higher heating temperature, and higher level of C- reactive protein （CRP）, however, non- ESBL UTI were associat-ed with higher rate of gross hematuria （P〈0.05）. The curative effect of empiric therapy for non- ESBL UTIs was significantly better than ESBL UTIs （100% vs 67.80%, P=0.0015）,the length of hospital stay was shorter [10 （8,13）vs 12 （9,18）, P=0.0245]. Logistic regression analysis showed that the antibiotics usage before urine culture, urinary tract anomalies, fever and high level of CRP were the predictive factors of urinary tract infection caused by ESBLs- producing E.coli. Conclusion The patients with younger age （〈2 years old）, fever, urinary tract anomalies, high level of CRP are prone to ESBL UTIs, for whomβ- lactamase inhibitor composite antibacterial drugs or carbopenems are recommended as empiric therapy. For the patients without those factors, the third generation cephalosporin could be optional.