Salmonella septic arthritis: a case report and review.

We describe a case of septic arthritis in a child with no apparent predisposing conditions. Salmonella virchow was isolated from her knee and faeces, both isolates being identical except for the latter's resistance to ampicillin. Evidence is presented for the acquisition of ampicillin resistance in vivo, including the demonstration of the R plasmid and its ready transferability to Escherichia coli. The recent literature on the subject is reviewed and the role of group CI salmonellae in invasive disease is examined.