Acquisition of multiple antibiotic resistance by Salmonella dublin from the gramnegative hospital flora, in a kidney allograft recipient.

The case of a kidney allograft recipient, who suffered from several episodes of Salmonella dublin sepsis following massive immunosuppressive therapy to overcome a transplant rejection crisis, is presented. The focus of sepsis was the chronic inflamed gallbladder. The Salmonella dublin strain isolated from the blood during the last episode was found to exhibit multiple resistance to antimicrobiol drugs. Because the resistance phenotype was characteristic for the gramnegative flora of the university hospital, it was suggested that transfer of a resistance plasmid, frequently found in gramnegative enterobacterial isolates, to the Salmonella strain had occurred in the patient. The comparative examination of a Klebsiella pneumoniae strain, representing the hospital flora, and Salmonella dublin revealed that both strains produced the aminoglycoside 3'-phosphotransferase type 1, the 2''-nucleotidyltransferase and the 3''-adenylyltransferase, enzymes responsible for resistance to aminoglycoside antibiotics. Furthermore, in both strains a TEM type beta-lactamase was found to render the organism resistant to penicillins and cephalosporins. Transfer experiments showed that the host ranges of the R-plasmids of both strains were identical. Furthermore, both plasmids were found to be the fi+ type. These data support the view of in vivo transfer of an R-plasmid from the enterobacterial hospital flora to a potential pathogen in a patient.