title: Microbiological tolerance in orthopaedic infections: delayed response of septic arthritis and osteomyelitis of the hip due to infection with tolerant Staphylococcus aureus.
abstract: A 14-year-old boy presented to another hospital with a clinical picture of septic arthritis. After aspiration of purulent material from the joint, empiric antibiotic treatment was initiated and an arthrotomy was performed. Antibiotic treatment was then modified to nafcillin according to microbiological sensitivity results of the isolated Staphylococcus aureus as determined by minimal inhibitory concentration testing. One week later purulent drainage recurred and open drainage had to be repeated; an abscess anterior to the joint was noted. Once again the infection failed to resolve, and the patient was transferred to our institution where a third arthrotomy had to be performed. The organism isolated at the first aspiration was reexamined and found to have a minimal bactericidal concentration to minimal inhibitory concentration ratio of 32, implying a tolerant organism. The antibiotic treatment was modified to an antibiotic not subject to the tolerance phenomenon, and the infection resolved without additional surgical intervention.
authors.affiliation: Department of Orthopaedic Surgery, Medical College of Wisconsin, Milwaukee, WI 53226, USA.
authors.forename: J G
authors.initials: JG
authors.lastname: Thometz
authors.forename: R
authors.initials: R
authors.lastname: Lamdan
authors.forename: K S
authors.initials: KS
authors.lastname: Kehl
authors.forename: M J
authors.initials: MJ
authors.lastname: Chusid
mesh_terms: D000293:Adolescent; D001170:Arthritis, Infectious / Q000188:drug therapy*; D004361:Drug Tolerance; D006801:Humans; D008297:Male; D008826:Microbial Sensitivity Tests; D009254:Nafcillin / Q000494:pharmacology / Q000627:therapeutic use*; D010019:Osteomyelitis / Q000188:drug therapy*; D010406:Penicillins / Q000494:pharmacology / Q000627:therapeutic use*; D013203:Staphylococcal Infections / Q000188:drug therapy*; D013211:Staphylococcus aureus / Q000187:drug effects
chemical_list: D010406:Penicillins; D009254:Nafcillin