Risk factors for community acquired urinary tract infections caused by extended spectrum β-lactamase (ESBL)
Extended-spectrum βlactamases (ESBLs)are β-lactamases that hydrolyze extended-spectrum cephalosporins with an oxyimino side chain. These cephalosporins include cefotaxime, ceftriaxone, and ceftazidime, as well as the oxyimino-monobactam aztreonam.Thus ESBLs confer resistance to these antibiotics and related oxyimino-βlactams. In recent years an increasing number of children with community acquired (CA)-UTI due to ESBL-producing organisms, especially E.coli,has been observed at our institution. The primary aim of this study was to determine the frequency of CA-UTIs caused by ESBL-producing bacterial pathogens in children seen at Children’s Hospital of Michigan during 2012-2016 and investigate the characteristics of childrento determine the risk factors associated with these infections. This study is a case control study Patients in the control group were matched by age, gender, and year of the CA-UTI due ESBL-producing E. coli group. Exclusion criteria included positive urine cultures >72 hours after hospitalization, patients with long term care facility stay within the preceding 3 months, postoperativeinfections within 10 days of surgery, and asymptomatic bacteriuria. Each urine culture was included once in the study.If more than one positiveESBL-producing E. coliurine culturewas present, the last clinical record with the least missing data was included. Positive urine culture was defined according to the method of collection of the urine sample. Bag specimens werenot included in the analysis. In midstreamspecimens of urine, UTI was defined as a positive urine culture ≥105CFU/mL or a positive urine culture (104-105CFU/mL) with pyuria of ≥10leukocytes per high power field. In specimens obtained through by bladder catheterization, growth of 104 -105CFU/mL was defined as UTI.Medical records ofpatients with UTI caused by ESBL-producing and non-ESBL producing E coliwere reviewed to obtain information on demographic characteristics, history of hospital visits, clinical findings, urine culturepathogen its antimicrobial susceptibilities, laboratory and imaging studies, comorbidities, treatment modalities,hospital course, complications,and outcome. Information was collected and analyzed for the following potential risk factorsfor ESBL infection: history of previous UTI, anatomic abnormalities of the urinary tract,antibiotic usage in the past 3months,previous hospitalizations,intensive care unit stay,surgeries,underlying neurologic abnormalitiessuch as spina bifidaor neurogenic bladder,previous infections,history of infection with ESBL-producing bacteria or other resistant bacteria,and intermittent urinary bladder catheterization. The results show a incrieasing risk of UTI with previouss use of antibiótics.