Incidence of antimicrobial resistant Escherichia coli urinary tract infections in the Australian Capital Territory

Dr Oyebola Fasugba1, Dr Anindita Das2, Dr George Mnatzaganian3, Professor Brett Mitchell4, Professor Peter Collignon2, Professor Anne Gardner1

1Australian Catholic University, Canberra, Australia,

2ACT Pathology, Canberra, Australia,

3La Trobe University, Bendigo, Australia,

4Avondale College of Higher Education , Wahroonga, Australia

Introduction: The prevalence of antimicrobial resistance in urinary Escherichia coli (E. coli) is increasing in Australia but incidence and risk factors for resistance are not well described. We evaluated the incidence of antimicrobial resistant E. coli urinary tract infections (UTI) in a cohort of Australian Capital Territory (ACT) residents. The associations of age, gender and urine sample source with risk of resistant infections were also investigated.

Methods: We utilised laboratory-based retrospective data from all ACT residents who submitted urine samples to ACT Pathology between January 2009 and December 2013.

Results:  A total of 146,915 urine samples from 57,837 ACT residents were identified over 5 years. The mean age of residents was 48 years (SD 26 years) with 64.4% female. The incidence of single-drug resistant E. coli UTI was high for ampicillin, trimethoprim and cefazolin (6.8%, 3.5% and 1.9% respectively). No pandrug-resistant E. coli UTI was detected. Five-year incidences of multidrug- and extensively drug-resistant E. coli UTI were 1.9% and 0.2% respectively. In multivariate logistic regressions, female sex and age over 38 years were significantly associated with single- and multidrug-resistance. The risk of single-drug resistance was significantly higher in samples from after-hours general practices compared to hospitals, office-hours general practices, community and specialist health services, (adjusted-odds ratio (OR) and 95% confidence intervals (CI) 2.6 (2.2–3.1)).

Conclusions: In this study, incidence of multidrug- and extensively drug-resistant E. coli UTI are low in comparison to international rates. Our findings have significant implications for antimicrobial prescribing.


Dr Bola Fasugba works as a research officer in the Nursing Research Institute, St Vincent’s Health Australia Sydney and Australian Catholic University. Her background is in medicine and public health research. She recently completed a PhD at the Australian Catholic University and has a master’s degree in public health and tropical medicine from James Cook University. Her main research focus is infection control.