背景：
氟喹诺酮类药物（FQs）在儿童中是罕见的处方，但小儿多药耐药（MDR） - 肠杆菌科（Ent）感染通常表现出FQ抗性（FQR）。我们试图定义儿童FQR和MDR-Ent的分子流行病学。

方法：
对芝加哥3家医院的MDR-Ent感染儿童进行病例对照分析。病例是患有第三代头孢菌素抗性（3GCR）和/或碳青霉烯抗性（CR）-Ent感染的儿童。 PCR和DNA分析评估了bla和质粒介导的FQR（PMFQR）基因。对照组为患有3GC和碳青霉烯类易感的儿童，其中Ent感染与年龄，来源和医院相匹配。我们评估了PMFQR Ent感染的临床流行病学预测因子。

结果：
来自儿童的169个3GCR和/或CR Ent分离株（中位年龄4.8岁）中，85个为FQR; 56（66％）含有PMFQR基因。主要生物是大肠杆菌和最常见的bla基因blaCTX-M-1组。在FQR分离株中，PMFQR基因突变分别包括分别为83％，15％，13％和11％的aac6'1b-cr，oqxA / B，qepA和qnrA / B / D / S. FQR大肠杆菌通常与phylogroup B2，ST43 / ST131相关。在多变量分析中，PMFQR Ent感染主要发生在非黑人 - 白人 - 西班牙裔种族（OR 6.5）的门诊患者（OR 33.1）中。芝加哥西南部的居民患PMFQR-Ent感染的可能性是参考地区的5倍，而芝加哥中部居住的风险降低了97％。未发现其他人口统计学，合并症，侵入性设备，抗生素使用或医疗保健差异。

结论：
感染与MDRO的强烈关联显示FQR与患者居住而非传统风险因素表明社区环境是这些病原体在儿童中传播的主要原因。

BACKGROUND:
Fluoroquinolones (FQs) are uncommonly prescribed in children, yet pediatric multidrug-resistant (MDR)-Enterobacteriaceae (Ent) infections often reveal FQ resistance (FQR). We sought to define the molecular epidemiology of FQR and MDR-Ent in children.

METHODS:
A case-control analysis of children with MDR-Ent infections at 3 Chicago hospitals was performed. Cases were children with third-generation-cephalosporin-resistant (3GCR) and/or carbapenem-resistant (CR)-Ent infections. PCR and DNA analysis assessed bla and plasmid-mediated FQR (PMFQR) genes. Controls were children with 3GC and carbapenem susceptible-Ent infections matched by age, source and hospital. We assessed clinical-epidemiologic predictors of PMFQR Ent infection.

RESULTS:
Of 169 3GCR and/or CR Ent isolates from children (median age 4.8 years), 85 were FQR; 56 (66%) contained PMFQR genes. The predominant organism was E. coli and most common bla gene blaCTX-M-1 group. In FQR isolates, PMFQR gene mutations included aac6'1b-cr, oqxA/B, qepA, and qnrA/B/D/S in 83%, 15%, 13% and 11% of isolates, respectively. FQR E. coli was often associated with phylogroup B2, ST43/ST131. On multivariable analysis, PMFQR Ent infections occurred mostly in outpatients (OR 33.1) of non-black-white-Hispanic race (OR 6.5). Residents of Southwest Chicago were >5 times more likely to have PMFQR-Ent infections than those in the reference region, while residence in Central Chicago was associated with a 97% decreased risk. Other demographic, comorbidity, invasive-device, antibiotic use, or healthcare differences were not found.

CONCLUSIONS:
The strong association of infection with MDROs showing FQR with patient residence rather than with traditional risk factors suggests that the community environment is a major contributor to spread of these pathogens in children.

https://www.ncbi.nlm.nih.gov/pubmed/30281548