Community-acquired bacteraemia and antibiotic resistance - Trends during a17-year period in a Danish county

Introduction: The aim was to ascertain the prevalence of antibiotic resista nce among blood isolates from patients with community-acquired bacteraemia and to relate it to antibiotic consumption. Methodology: Cases of community-acquired bacteraemia were identified in a r egional bacteraemia register in the County of Northern Jutland. The study i ncluded 3974 episodes in 3805 patients during a 17-year period. Total regio nal consumption of antibiotics was expressed in Defined Daily Doses (DDD). Results: The prevalence of antibiotic resistance was stable with few except ions. The most notable time trend was noted for Escherichia coli for which the prevalence of resistance to ampicillin increased from 17% (95% confiden ce limits (CL) 12-23%) to 28% (95% CL 23-33%); for other Enterobacteriaceae the increase was from 73% (95% CL 61-83%) to 86% (95% CL 77-92%). The prev alence of resistance to aminoglycosides, fluoroquinolones and third-generat ion cephalosporins remained low among all isolates of Enterobacteriaceae. R egional antibiotic consumption ranged from 10.2 to 13.6 DDD/1000 inhabitant s/day. Consumption of penicillins with Gram-negative spectrum reached a max imum of 4.6 DDD/1000 inhabitants/day in 1993 and decreased towards the end of the study period. The prevalence of ampicillin-resistant E. coli was pos itively correlated with consumption of penicillins with Gram-negative spect rum; the correlation was stronger when adjustment was made for co-selection by tetracyclines and sulphonamides. Conclusion: Therapeutic options for community-acquired bacteraemia have not yet become seriously limited by prevalence of acquired antibiotic resistan ce. Still we found some evidence that consumption of penicillins with Gram- negative spectrum, sulphonamides and tetracyclines promotes antibiotic resi stance among Enterobacteriaceae.