In vitro activity of tigecycline against resistant micro-organisms isolated from burn patients

Infections in burn patients are usually caused by multidrug-resistant micro-organisms. Tigecycline, a derivative of glycylcyclines, is an effective antibiotic against the resistant strains. The aim of this study is to determine the in vitro activity of tigecycline against the multidrug-resistant bacteria isolated from burn patients. Fourty-seven bacteria isolated from 118 patients hospitalized in the burn unit during 2003–2006 were included in the study. Gram-negative bacteria that were resistant to at least six broad-spectrum antibiotics, methicillin-resistant staphylococci and ampicillin-resistant enterococci were studied. Minimal inhibitory concentration values of tigecycline against these bacteria were tested by E-test strips. Susceptibility breakpoints were determined according to the previous studies; ≤0.25 mg/L for enterococci, ≤0.5 mg/L for staphylococci and ≤2 mg/L for Acinetobacter baumannii. Thirty-six percent of the materials were obtained from tissue specimens, 30% from wound, 25% from blood and 9% from other samples (e.g., catheter, tracheal aspiration, urine). MIC90 values were 2, 0.25 and 1.5 mg/L and susceptibility rates were 99.4%, 93.6%, 85.5% for A. baumannii, enterococci and MRSA, respectively. To conclude, this study demonstrated that tigecycline exhibits in vitro activity against clinical isolates of MDR A. baumannii, MRSA, and Enterococcus spp. isolated from burn patients. Tigecycline is a promising therapeutic option for difficult to treat burn infections due to these pathogens.