Kluyvera co-infection in two solid organ transplant recipients:: an emerging pathogen or a colonizer bystander?

Kluyvera species are opportunistic, gram-negative bacilli in the family Enterobacteriaceae. Ordinarily occurring as a commensal, Kluyvera have been reported to cause serious infections in immunosuppressed and immunocompetent hosts, causing diarrhea, urinary infections, peritonitis, and cholecystitis. We report Kluyvera infections in 2 solid organ transplant recipients. An 18-year-old female with alfa-1 antitrypsin deficiency underwent living donor liver transplantation and presented 6 months later with a liver abscess. The abscess aspirate grew mixed organisms including Kluyvera cryocrescens. A 22-year-old female with renal failure secondary to focal segmental glomerulosclerosis underwent a deceased donor kidney transplant and presented 3 months later with pyelonephritis; the urine culture grew Kluyvera ascorbata. Both patients improved only when their antibiotic coverage was broadened to include Kluyvera. The isolation of Kluyvera as a pathogen in transplant patients emphasizes that this commensal organism may be virulent in this patient population.