Microbial surveillance during human pancreatic islet isolation

Abstract

The aim of the study was to investigate microbiological contamination rate during human pancreatic islet isolation. Between 1996 and 2002, pancreas preservation media and post-purification islet preparations were screened for microbiological contamination. After arrival in the laboratory, pancreata were washed prior to enzyme perfusion with either Hank's balanced salt solution (Group I, n = 170, 1996 to 2001) or decontaminated with polyvidonum-iodine, cefazoline, and amphotericine B (Group II, n = 45, 2001 to 2002). Microbiological contamination of preservation media was observed in 56% and 84% for Groups I and II, respectively. Analysis of contaminants revealed 74% Gram-positive, 21% Gram-negative bacteria and 5% fungi. Duration of transport had an influence on the rate of contamination (P < 0.05). After islet isolation, Group I presented microbial contamination of 16 islet preparations (9.4%) [i.e. Gram-positive bacteria (n = 10), Gram-negative bacteria (n = 4), and fungi (n = 2)]. In Group II, only 2 islet preparations (4.4%) presented microbial contamination. Microbial contamination during pancreas procurement occurs frequently. Most microorganisms are eliminated during islet isolation, and de novo contaminations during islet isolation are rare. Pancreas decontamination reduces the risk of infection of the final islet preparation.