Multiply Antibiotic-Resistant Staphylococcus aureus: Introduction, Transmission, and Evolution of Nosocomial Infection

Abstract

A burn patient with a multiply antibiotic-resistant S. aureus infection was transferred to Harborview Medical Center [Seattle, Washington, USA] from a burn unit in another state. Despite standard wound precautions, transmission to 34 patients occurred during the subsequent 15 mo. Twenty-seven of the patients were infected. Disease included pneumonia, empyema, bacteremia, endocarditis, osteomyelitis, and burn and wound infections. Seventeen of the 34 patients died. Phage typing and plasmid analysis showed the spread of multiply resistant S. aureus from the burn unit to the surgical intensive care unit where a study evaluating the use of chloramphenicol in cases of bowel sepsis was in progress. During this period the organism became resistant to chloramphenicol by acquiring either of 2 chloramphenicol R-plasmids. Using plasmid profiles and antibiograms, 4 epidemic strains were identified that assisted in identifying patient and personnel reservoirs. The outbreaks was controlled only after rifampin was added to vancomycin treatment of infected patients, which correlated with eradication of ther carrier state.