Patterns of Urinary Escherichia Coli Resistance in Victoria: A Cause for Concern?

1. No. 103 Patterns of Urinary Escherichia Coli Resistance in Victoria: A Cause for Concern? Antonio de Sousa1, Numan Kutaiba1, Gideon Blecher1, David Low1, Kara Richardson2, Lydia Johns-Putra1 Departments of Urology1 and Microbiology2, Ballarat Health Services, Victoria, Australia Introduction E.Coli is the most common organism isolated in uncomplicated acute bacterial cystitis The emergence of multi-resistant E.Coli strains poses a challenge for clinicians Regional and national variation exists in patterns of resistance Results A total of 8,259 episodes of urinary E.Coli were isolated in 3 months 7873 samples were from metropolitan Melbourne (all community samples) 386 were from Ballarat, comprising 237 community-acquired isolates and 149 samples from hospital inpatients There was a 90% female preponderance across all sample populations Table 1. Comparison of community acquired UTI in Ballarat and Melbourne. Note the high rate of resistance to amoxycillin in Melbourne; it is not recommended by therapeutic guidelines for UTI. Resistance to trimethoprim was higher in the Melbourne population. Rates of resistance for hospital and community acquired E coli in Ballarat were comparable, except for amoxycillin which demonstrated 33.6% resistance in hospital vs 3.8% in the community (p=0.0001) Table 2. Our local rates of resistance compare favourably to international series, particularly with regard to gentamicin and quinolone resistance Aim To determine the local rate of antimicrobial resistant E.coli in the community To ensure that our empiric antibiotic therapy for UTI is appropriate; we use trimethoprim as first line for uncomplicated UTI To compare local patterns of resistance with other cohorts both within Australia and overseas Methods A retrospective analysis of urinary E.Coli isolates was performed Data was collated over a 3 month period, from January through March 2011 Urine samples were obtained from the local Ballarat and metropolitan Melbourne laboratories Sensitivity and resistance profiles to commonly prescribed antibiotics (including those recommended by therapeutic guidelines) were established for each sample group Where possible, comparison was made between hospital and community-acquired infections Statistical analysis was performed using online software Conclusions Whilst all first line antibiotics recommended by the TG would be effective in treating the majority of E.Coli UTI in our area, 1 in 6 isolates will be resistant to trimethoprim, compared to 1 in 5 in Melbourne These rates are quite high and should prompt us to consider a change in our prescribing practices The continuing evolution of antimicrobial resistance makes it important to know and reassess local patterns regularly References Barnett BJ, Stephens DS. Am J Med Sci. 1997 Oct;314(4):245-9. Pitout JD, Laupland KB. Lancet Infect Dis. 2008 Mar;8(3):159-66. Therapeutic Guidelines Limited. etg34, July 2011. Cullen IM, et al. 2011 BJU Int. [Epub ahead of print] Zhanel GG, et al. Int J Antimicrob Agents. 2006 Jun;27(6):468-75. Lee SJ, et al. J Infect Chemother. 2011 Jun;17(3):440-6. Acknowledgements Thanks to David Cook, Richard McMullin, Lachlan Dodds and Robert Forsyth for their guidance Poster presentation sponsor