Resistance to second- and third-generation cephalosporins among Escherichia coli and Klebsiella species is rare in Finland.

OBJECTIVE

To investigate the antimicrobial resistance of Escherichia coli and Klebsiella spp. from pus, urine and respiratory specimens, with particular emphasis on the detection of third-generation cephalosporin resistance.

METHODS

E. coli (698) and Klebsiella sp. (476) strains from pus, respiratory and urinary specimens from hospital patients were collected from 19 laboratories. Data about consumption of third-generation cephalosporins and cefuroxime were collected from 24 hospitals. Antimicrobial susceptibility was tested with disk diffusion in primary laboratories and by an agar dilution method. Extended-spectrum beta-lactamase (ESBL) production was studied with a double disk synergy test and an ESBL Etest. The beta-lactamase classes were characterized with polymerase chain reaction probes of the TEM and SHV beta-lactamase families and isoelectric focusing.

RESULTS

Only 0.6% of E. coli and 2.3% of Klebsiella spp. strains were resistant or intermediately resistant to cefotaxime, ceftriaxone and/or ceftazidime. The ESBL producers detected comprised one E. coli harboring TEM-like genes and five Klebsiella pneumoniae strains, two of which harbored SHV-like genes, two TEM-like genes and one both. Although consumption of cefuroxime has increased in the years 1990-1994, from 3.48 to 5.84 defined daily doses/100 bed-days, and the consumption of third-generation cephalosporins from 1.25 to 1.94 defined daily doses/100 bed-days, cefuroxime resistance of E. coli was only 3%.

CONCLUSION

Although the use of broad-spectrum cephalosporins has increased, resistance to second- and third-generation cephalosporins is still rare in Finland.