Resistance among Escherichia coli to sulphonamides and other antimicrobials now little used in man.
OBJECTIVE
We investigated whether sulphonamide resistance in Escherichia coli remained prevalent in 2004, 9 years since the formal introduction of a UK prescribing restriction on co-trimoxazole. Resistance to other agents no longer in common use was also examined.


METHODS
Consecutive urinary E. coli isolates were obtained at the diagnostic microbiology laboratory of the Royal London Hospital from January to March 2004. The presence of the sulphonamide resistance genes, sul1, sul2 and sul3, and the class I integrase gene, int1, were determined by PCR.


RESULTS
Of the 391 E. coli isolates recovered in 2004, 45.5% were sulphonamide-resistant compared with 46.0% in 1999 and 39.7% in 1991. The sul2 gene remained the most prevalent sulphonamide resistance determinant, present in 81% of resistant isolates in 2004 compared with 79% and 67% in 1999 and 1991, respectively; 28% of resistant isolates carried both sul1 and sul2 genes; sul3 was not found. Resistance to streptomycin also remained common, whereas resistance to chloramphenicol and kanamycin had decreased since 1999.


CONCLUSIONS
Sulphonamide resistance in E. coli persists undiminished despite the prolonged withdrawal of this antibiotic in the UK; resistance to streptomycin also seems stable whilst that to chloramphenicol and kanamycin is declining.
Bean
David C
DC
Centre for Infectious Disease, Barts and The London School of Medicine and Dentistry, Queen Mary, University of London, 4 Newark Street, London E1 2AT, UK. d.c.bean@qmul.ac.uk
Livermore
David M
DM
Papa
Iro
I
Hall
Lucinda M C
LM
D000900:Anti-Bacterial Agents / Q000494:pharmacology*; D001426:Bacterial Proteins / Q000235:genetics; D002352:Carrier Proteins / Q000235:genetics; D002701:Chloramphenicol / Q000494:pharmacology; D004269:DNA, Bacterial / Q000032:analysis / Q000235:genetics; D004094:Dihydropteroate Synthase / Q000235:genetics; D024881:Drug Resistance, Bacterial / Q000235:genetics*; D004926:Escherichia coli / Q000187:drug effects* / Q000235:genetics / Q000302:isolation & purification; D004927:Escherichia coli Infections / Q000382:microbiology; D029968:Escherichia coli Proteins / Q000235:genetics; D006801:Humans; D019426:Integrases / Q000235:genetics; D007612:Kanamycin / Q000494:pharmacology; D008826:Microbial Sensitivity Tests; D016133:Polymerase Chain Reaction; D013307:Streptomycin / Q000494:pharmacology; D013449:Sulfonamides / Q000494:pharmacology*; D006113:United Kingdom; D014552:Urinary Tract Infections / Q000382:microbiology
D000900:Anti-Bacterial Agents; D001426:Bacterial Proteins; D002352:Carrier Proteins; D004269:DNA, Bacterial; D029968:Escherichia coli Proteins; C091882:Sul1 protein, E coli; C491369:Sul2 protein, bacteria; D013449:Sulfonamides; D007612:Kanamycin; D002701:Chloramphenicol; D004094:Dihydropteroate Synthase; C487459:Sul3 protein, E coli; D019426:Integrases; D013307:Streptomycin