[Surveillance of antibiotic resistance and antibiotic consumption in Medimurje].

INTRODUCTION: Bacterial resistance is a global problem. More than 60 years of the large-scale use of antibiotics have resulted in a number of microorganisms which are resistant or multiresistant to different antimicrobial drugs. A correlation between the use of antibiotics and bacterial resistance has been proved for many different groups of antibiotics. AIM: The aim of this study was to determine the connection between bacterial resistance and antibiotic consumption in the region. MATERIAL AND METHODS: The surveillance of antibacterial resistance in Medimurje started in 1997 as part of the activities of the Croatian Commitee for Antibiotic Resistance Surveillance at the Academy of Medical Sciences of Croatia. The utilization of antibiotics was defined according to WHO and expressed in defined daily doses. The surveillance of their consumption and comparison of different drugs and different regions is done by TID (Thousands of Inhabitants Daily), which describes the population proportion taking a drug in a particular region per day. The analysis of antibiotic consumption was based on distribution data. RESULTS: The consumption of antibiotics according to the ATC/TID system in Medimurje in 2002 was 18.06 TID; TID was 0.86 and 17.2 for inpatients and outpatients, respectively. The consumption was recorded for the penicillin group of antibiotics in both hospital and outpatient utilization, followed by cephalosporins, tetracyclines and macrolides in outpatient utilization, and by cephalosporins, aminoglycosides and quinolones in hospital utilization. Analysis of the consumption of the penicillin group of antibiotics in outpatient utilization revealed it to be predominated by the wide spectrum penicillins and co-amoxiclav, whereas the latter prevailed in hospital utilization. The surveillance of bacterial resistance in Medimurje during the last 5 years (1998-2002) pointed to a high resistance to macrolides (23%-33%) in BHS. The outpatient utilization of macrolides was on the 4th place with 1.15 TID. Azithromycin accounted for 87% of macrolide consumption. In this region, pneumococci showed an extremely high rate of penicillin resistance (49%-68%), although this resistance was mostly intermediate. It was obviously due to the high selective antibiotic requirements, especially for the strains involving respiratory tract. High resistance to macrolides (15%-38%), cotrimoxasol (42%-50%) and tetracyclines (30%) pointed to the high proportion of multiresistant pneumococcal strains. A significantly lower resistance to penicillin (30%), which was strictly intermediate, was recorded in isolates from primary sterile materials. Resistance to other antibiotic groups was also lower. The rate or MRSA in the group of S. aureus as 2%-3% in the five-year period. E. coli was the most frequent isolate in both inpatient and outpatient settings. Analysis of resistance during the last 5 years yielded no specific findings. The resistance of wide spectrum penicillin was 51%-58%, with a very low portion of ESBL strains (<1%), no imipenem resistant strain; resistance to quinolones was 4%-8%, and to cotrimoxasole was 30%. There were no invasive E. coli strains resistant to 2nd and 3rd generations of cephalosporins, aminoglycosides, quinolones and carbapenemes, while the resistance to wide spectrum penicillin, 1st generation cephalosporins and cotrimoxasole was the same as in other groups of E. coli. DISCUSSION: Surveillance of antibiotic resistance in a local region is very important, because it shows the local pattern of resistance, helps choose useful empirical therapy and most efficacious antibiotic therapy, and can modify antibiotic therapy accordingly. CONCLUSION: There is no clear correlation between antibiotic consumption and bacterial resistance, especially in case of outpatient isolates.