title: Five-Year Antimicrobial Resistance Patterns of Urinary Escherichia coli at an Australian Tertiary Hospital: Time Series Analyses of Prevalence Data.
abstract: This study describes the antimicrobial resistance temporal trends and seasonal variation of Escherichia coli (E. coli) urinary tract infections (UTIs) over five years, from 2009 to 2013, and compares prevalence of resistance in hospital- and community-acquired E. coli UTI. A cross sectional study of E. coli UTIs from patients attending a tertiary referral hospital in Canberra, Australia was undertaken. Time series analysis was performed to illustrate resistance trends. Only the first positive E. coli UTI per patient per year was included in the analysis. A total of 15,022 positive cultures from 8724 patients were identified. Results are based on 5333 first E. coli UTIs, from 4732 patients, of which 84.2% were community-acquired. Five-year hospital and community resistance rates were highest for ampicillin (41.9%) and trimethoprim (20.7%). Resistance was lowest for meropenem (0.0%), nitrofurantoin (2.7%), piperacillin-tazobactam (2.9%) and ciprofloxacin (6.5%). Resistance to amoxycillin-clavulanate, cefazolin, gentamicin and piperacillin-tazobactam were significantly higher in hospital- compared to community-acquired UTIs (9.3% versus 6.2%; 15.4% versus 9.7%; 5.2% versus 3.7% and 5.2% versus 2.5%, respectively). Trend analysis showed significant increases in resistance over five years for amoxycillin-clavulanate, trimethoprim, ciprofloxacin, nitrofurantoin, trimethoprim-sulphamethoxazole, cefazolin, ceftriaxone and gentamicin (P<0.05, for all) with seasonal pattern observed for trimethoprim resistance (augmented Dickey-Fuller statistic = 4.136; P = 0.006). An association between ciprofloxacin resistance, cefazolin resistance and ceftriaxone resistance with older age was noted. Given the relatively high resistance rates for ampicillin and trimethoprim, these antimicrobials should be reconsidered for empirical treatment of UTIs in this patient population. Our findings have important implications for UTI treatment based on setting of acquisition.
authors.affiliation: Faculty of Health Sciences, Australian Catholic University, Australian Capital Territory, Australia.
authors.forename: Oyebola
authors.initials: O
authors.lastname: Fasugba
authors.affiliation: Faculty of Health Sciences, Australian Catholic University, Australian Capital Territory, Australia.|Faculty of Arts, Nursing and Theology, Avondale College of Higher Education, Wahroonga, New South Wales, Australia.
authors.forename: Brett G
authors.initials: BG
authors.lastname: Mitchell
authors.affiliation: College of Science, Health and Engineering, La Trobe Rural Health School, La Trobe University, Victoria, Australia.
authors.forename: George
authors.initials: G
authors.lastname: Mnatzaganian
authors.affiliation: Australian Capital Territory Pathology, Canberra Hospital and Health Services, Garran, Australian Capital Territory, Australia.
authors.forename: Anindita
authors.initials: A
authors.lastname: Das
authors.affiliation: Australian Capital Territory Pathology, Canberra Hospital and Health Services, Garran, Australian Capital Territory, Australia.|Medical School, Australian National University, Acton, Australian Capital Territory, Australia.
authors.forename: Peter
authors.initials: P
authors.lastname: Collignon
authors.affiliation: Faculty of Health Sciences, Australian Catholic University, Australian Capital Territory, Australia.
authors.forename: Anne
authors.initials: A
authors.lastname: Gardner
mesh_terms: D000368:Aged; D000667:Ampicillin / Q000494:pharmacology / Q000627:therapeutic use; D000900:Anti-Bacterial Agents / Q000494:pharmacology* / Q000627:therapeutic use; D001315:Australia / Q000453:epidemiology; D003430:Cross-Sectional Studies; D024881:Drug Resistance, Bacterial / Q000187:drug effects*; D004926:Escherichia coli / Q000187:drug effects* / Q000302:isolation & purification; D004927:Escherichia coli Infections / Q000188:drug therapy / Q000453:epidemiology*; D005260:Female; D006801:Humans; D008297:Male; D008826:Microbial Sensitivity Tests; D008875:Middle Aged; D015995:Prevalence; D012621:Seasons; D062606:Tertiary Care Centers; D014295:Trimethoprim / Q000494:pharmacology / Q000627:therapeutic use; D014552:Urinary Tract Infections / Q000188:drug therapy / Q000453:epidemiology*; D001618:beta-Lactamases / Q000378:metabolism
chemical_list: D000900:Anti-Bacterial Agents; D000667:Ampicillin; D014295:Trimethoprim; D001618:beta-Lactamases