In vitro Susceptibility of Pseudomonas aeruginosa Isolated from a Burn Center to Silver Sulfadiazine and Silver Nitrate in Shiraz, South of Iran

Background: pseudomonas aeruginosa, as an etiologicalagent, has a prominent infection role in serious burned patients.burned patients usually treated with antiseptic ointmentssuch as silver sulfadiazine (ssd). this study evaluatedthe effectiveness of 1% ssd and different concentrationsof si iver nitrate solution (sns) on resistant isolates ofp. aeruginosa.methods: three groups of p. aeruginosa isolates' were collectedconsisting of 63 strains from burned patients (group i),15 strains from burn-hospital environment (group ii) and 70strains from non-burn patients as control group. the minimuminhibitory concentrations (mics) of ssd and sns were determinedby agar dilution method and their susceptibility tossd was evaluated by agar well diffusion method.results: in group i, 60 (95%) strains were resistant to ssd,whereas only 5 of them were resistant to sns. in group ii,eight out of 15 strains were resistant to ssd with mics similarto group i while they did not show any resistance to sns(p(less than)o.oo i). in control group, all strains were sensitive to ssdand sns (p(less than)o.ooi)conclusion: most of burned patient isolates were resistant tossd while most of them were sensitive to sns. in contrast, allthe control isolates were sensitive to ssd and sns. frequentadministrations of ssd ointment in burned patients surelyhave caused resistant strains to emerge. cessation of sns applicationin clinic or less administration of ssd in non-burnpatients did not induce resistance strains.