Choice of antibiotic for empirical therapy of acute cystitis in a setting of high antimicrobial resistance

Abstract

Background: A high prevalence of antimicrobial resistance among urinary isolates in the Garhwal region of Uttaranchal.

Aims: To identify the most appropriate antibiotic for empirical treatment of community-acquired acute cystitis on the basis of local antimicrobial sensitivity profile.

Settings and design: A prospective clinico-microbiological study including all clinically diagnosed patients with community acquired acute cystitis attending a tertiary care teaching hospital over a period of three years.

Methods and material: Clean-catch midstream urine specimens, from 524 non-pregnant women with community-acquired acute cystitis, were subjected to semi-quantitative culture and antibiotic susceptibility by the Kirby- Bauer disc diffusion method. A survey was also conducted on 30 randomly selected local practitioners, to know the prevalent prescribing habits in this condition.

Statistical analysis: The difference between the susceptibility rates of E. coli isolates to Nitrofurantoin and the other commonly prescribed antibiotics was analysed by applying the z test for proportion.

Results: 354 (67.5%) specimens yielded significant growth of E. coli.> 35% of the urinary E.coli isolates were resistant to the fluoroquinolones, which were found to be the most commonly used empirical antibiotics in acute cystitis. Resistance was minimum against Nitrofurantoin (9.3%, 33) and Amikacin (11.0%,39).> 80% of the fluoroquinolone-resistant strains were found to be sensitive to Nitrofurantoin.

Conclusion: The best in vitro susceptibility profile in our study has been shown by Nitrofurantoin and a significantly high proportion of the urinary E. coli isolates have already developed resistance to the currently prescribed empirical antibiotics, viz. the fluoroquinolones. In view of these in vitro susceptibility patterns, a transition in empirical therapy appears imminent.