Antibiotic resistance patterns among blood culture isolates in a Danish county 1981-1995

All episodes of bacteraemia during a 15-year period (1981-1995) in the Coun ty of Northern Jutland, Denmark, were analysed with regard to antibiotic re sistance. A total of 8840 isolates from 7938 episodes of bacteraemia was id entified. Over time, no changes in bacterial aetiology were noted. Three is olates of Staphylococcus aureus were methicillin resistant (0.2%) and six w ere gentamicin resistant (0.4%). Among coagulase-negative staphylococci a 1 4% increase in resistance to penicillin was observed (95% confidence interv als, CI: 2-26%). Likewise, the frequency of resistance to methicillin, gent amicin and erythromycin increased, the corresponding figures being 38% (CI: 26-50%), 26% (CI: 14-38%) and 32% (CI: 16-50%), respectively, whereas a 14 % decrease in resistance to streptomycin was recorded (CI: 4-24%). A 20% (C I: 2-37%) increase of coagulase-negative staphylococci resistant to three o r more antibiotics was observed. The frequency of ampicillin resistance inc reased by 9% among Escherichia coli (CI: 4-13%) and by 10% (CI: 6-14%) in a ll Enterobacteriaceae. Among Enterobacteriaceae the level of resistance to third-generation cephalosporins, carbapenems, aminoglycosides and fluoroqui nolones remained low (<1%). The frequency of resistance to three or more an tibiotics remained fairly stable among Enterobacteriaceae, although a sligh t increase was noted among E. coli (5%; CI: 0-10%) The recommended regimen for empirical antibiotic treatment in this region (a combination of penicil lin G or ampicillin and an aminoglycoside) provided an overall coverage of 94% (CI: 94-95%), although a slight decrease was noted at the end of the pe riod. In conclusion, acquired antibiotic resistance was maintained at a low level compared with most other European countries and regions during the 1 5-year period studied.