In vitro Susceptibility to Everninomycin of Gram-Positive Nosocomial Pathogens Isolated from Intensive Care Units in Germany

Background: Gram-positive bacteria are increasingly found to be causative pathogens in nosocomial infections, and the occurrence of vancomycin resistance in enterococci as well as staphylococci has prompted the investigation of alternative antimicrobial agents active against these strains. Everninomycin, a new oligosaccharide antibiotic, has excellent in vitro activity against gram-positive bacteria, including those resistant to vancomycin. However, avilamycin, a related compound, has been used in Europe as a growth promoter in animal food for years and concern has been raised that cross-resistance in clinical isolates may arise. Methods: We studied a collection of 268 nosocomial gram-positive isolates from intensive care unit patients with nosocomial pneumonia, urinary tract infection and sepsis, using standard in vitro susceptibility testing. Results: It could be shown that all species tested were exquisitely sensitive to everninomycin (MIC90 of 0.38 µg/ml for Staphylococcus aureus, 0.5 µg/ml for enterococci and 0.75 µg/ml for coagulase-negative staphylococci). Furthermore, no difference could be observed between methicillin-resistant and methicillin-sensitive S. aureus or between Enterococcus faecium and Enterococcus faecalis. Conclusions: These results suggest that everninomycin is a promising antibiotic for the treatment of nosocomial infections in intensive care unit patients and that the use of a related substance as an additive in animal food has not yet promoted resistance in clinical isolates.