a University of Trnava, School of Health, Trnava and Nitra; b Department of Pharmacy, State Institute of Drug Control, Bratislava; c National Reference Laboratory of Antibiotic Resistance, Bratislava; d Antibiotic Committee of Ministry of Health, Bratislava, Slovak Republic
Sir,
Previously, investigators from Slovenia have reported resistance to ciprofloxacin in community isolates of Escherichia coli increasing from 3.6% to 9.2% over 5 years, while use of quinolones increased from 0.59 to 1.5 defined daily doses (DDD)/1000 inhabitants/year.1 We have compared resistance rates to ofloxacin in community isolates of E. coli and Staphylococcus aureus from the surveillance system of the National Reference Laboratory of Antibiotic Resistance, together with data on the consumption of quinolones (ofloxacin, ciprofloxacin, pefloxacin and norfloxacin). Consumption of quinolones increased from 0.47 in 1995 to 1.13 in 1998 (DDD/1000 inhabitants/year) but subsequently decreased to 0.99 in 2000. However, resistance to ofloxacin has remained low: 1.6% in 1996 and 1.3% in 2000 in E. coli; 1.1% in 1996 and 0.7% in 2000 in S. aureus (4653 E. coli and 6406 S. aureus community strains were tested by the NCCLS method).2 Despite the increase of quinolone use there appears to have been no increased resistance in community isolates of E. coli and S. aureus. Two possibilities for this finding may be that in 1997 a restrictive antibiotic policy of the Ministry of Health Antibiotic Committee was implemented, where certain groups of antibiotics (including quinolones) were restricted for use in general practice, and in 19981999 a new categorization of the National Health Maintenance Organization (HMO-VZP) was begun, with co-payments by the patient (520% for quinolones) for formerly free antibiotics.
Other authors have noted a correlation between quinolone usage and emergence of resistance3,4 and it would be interesting to discover whether other countries could demonstrate a reduction in in vitro resistance by reducing quinolone consumption, as appears to have happened in Slovenia.
Notes
* Correspondence address. St Elizabeth Cancer Institute, OKF and Trnava University, Heydukova 10, Bratislava, Slovakia. Tel/Fax: +421-7-52924308; E-mail: svetlansky{at}mailbox.sk
References
1
.
iz
man, M., Orazem, A., Knizan, V. & Hergout, V. (2001). Correlation between increased consumption of fluoroquinolones in outpatients and resistance of Escherichia coli from urinary tract infections. Journal of Antimicrobial Chemotherapy 47, 502.
2 . National Committee for Clinical Laboratory Standards. (1997). Methods for Dilution Antimicrobial Susceptibility Testing for Bacteria that Grow AerobicallyFourth Edition: Approved Standard M7-A4. NCCLS, Wayne, PA.
3 . Melo Cristino, J. (1999). Corelation between consumption of antibiotics in humans and development of resistance in bacteria. International Journal of Antimicrobial Agents 12, 199202.[ISI][Medline]
4 . Eva, J., Lopez, P. M., Martinez, C., Cia, B. M. & Remiz-Lopez, I. (1998). Emergence of ciprofloxacin resistance in E. coli isolates after widespread use of quinolones. Diagnostic Microbiology and Infectious Disease 30, 1037.[ISI][Medline]