Drug resistance in relation to use of silver sulphadiazine cream in a burns unit.

Abstract

SUMMARY Topical chemoprophylaxis of extensive burns with silver sulphadiazine cream led to a large increase in the proportion of sulphadiazine-resistant Gram-negative bacilli in a bums unit. When all sulphonamide treatment in the ward was stopped, the incidence of sulphonamide-resistant strains fell back to levels similar to those recorded when silver sulphadiazine treatment was introduced. This was associated with a large reduction in the incidence of resistance of certain Gramnegative bacilli (especially Klebsiella sp) to several antibiotics.Transferable resistance to sulphadiazine, shown by conjugation experiments with Escherichia coli K12, was found in a majority of the strains of Klebsiella sp tested, and in some other species. A pattern of transferable resistance to tetracycline, cephaloridine, chloramphenicol, ampicillin, carbenicillin, and sulphadiazine (T Ce Cl A Ca S) was found in four of the 22 strains of Klebsiella tested, and closely related pattems were transferred by five other strains. These patterns of resistance were commonly found in Klebsiella sp isolated from bums in the period before the withdrawal of sulphonamides from the ward but were found in none of the Klebsiella strains isolated in the first six months after that period. Strains of Acinetobacter and Proteus, in which transferable resistance was not found, showed no appreciable fall or rise in sulphadiazine resistance; there was no fall in resistance of these organisms to tetracycline, cephaloridine, chloramphenicol, ampicillin or carbenicillin on withdrawal of sulphonamides from the ward, but there were substantial falls in resistance of Acinetobacter to kanamycin, gentamicin, trimethoprim, and tetracycline which were probably not caused by the withdrawal of sulphonamides.

Acetic acid used for the elimination ofPseudomonas aeruginosafrom burn and soft tissue wounds

“…The choice of antibacterial agents for topical use on burn wounds is limited. Although silver sulphadiazine is widely used in burn units in the UK, problems of bacterial resistance have occurred during prolonged use (19). In view of the results in this and previous studies, we conclude that the use of acetic acid (5 per cent) topically to burn and soft tissue wounds is an effective treatment for reducing the incidence of P. aeruginosa, avoiding the expense and adverse effects of other topical agents and antibiotics.…”

Effects of silver sulphadiazine on the production of exoproteins by Staphylococcus aureus

“…There is no cross-reaction between sulphonamide resistance and sensitivity to AgSD but sulphonamide-resistant S. aureus are killed more slowly than sulphonamidesensitive strains [21,22]. Use of AgSD can also increase the incidence of sulphonamide resistance on a burns unit [22], which suggests that the sulphadiazine is having some effect. Sulphadiazine potentiates the action of AgSD and it has been suggested that this may be due to a reduced degree of ionisation of the AgSD, thus slowing the release of Ag into the medium [18].…”

“…The sulphonamide moiety is at a concentration below that required for antimicrobial action [20]. There is no cross-reaction between sulphonamide resistance and sensitivity to AgSD but sulphonamide-resistant S. aureus are killed more slowly than sulphonamidesensitive strains [21,22]. Use of AgSD can also increase the incidence of sulphonamide resistance on a burns unit [22], which suggests that the sulphadiazine is having some effect.…”

Potential risks and benefits of nanotechnology: perceptions of risk in sunscreens

“…In vitro evidence of bacterial resistance to ionic silver Exposure to silver may contribute to the selection of bacteria that are intrinsically resistant to silver (Wenzel et al 1976;Bridges and Lowburry 1977;Haefeli et al 1984;Silver 2003;Davis et al 2005). Emerging silver-resistance from environmental bacterial isolates has been documented in Enterobacteriaceae (Hendry et al 1979;Kaur and Vadehra 1986;Trevors 1989, 1990) and in Acinetobacter baumanii (Deshpande and Chopade 1994) under experimental conditions.…”