Effects of bacterial infection on insulin secretory capacity of human adult pancreatic islets

Abstract

This study aims to determine the origin of bacterial contamination of pancreatic tissue cultures, as well as its influence on insulin secretory activity (expressed as stimulation index [SI]) of the pancreatic islets. Pancreatic tissue was obtained after pancreatectomy in patients who had chronic pancreatitis or benign tumours. Islets were isolated under aseptic conditions by a manual method. Microbiological analyses were performed by standard procedures and the SI was determined on the first and seventh day of cultivation. In cultures contamminated by Pseudomonas, SI was 1.58±1.16 on day 1 and 0.22±0.14 on day 7 (P<<0.01). Cultures contaminated by Enterobacter showed an SI of 0.21±0.1 on day 1, which increased to 1.19±0.66 on day 7 (P<0.01). In cases of Staphylococcus contamination, SI was 0.07±0.05 on day 1 and 0.33±0.21 on day 7 (P<<0.01). The study shows that cell culture contamination originates from an original pancreatic tissue infection. The presence of bacteria may reduce or increase insulin secretion in cell culture, depending on the type of microorganism, and this can provoke reduced or elevated levels of insulin secretion in recipients, thus increasing the chances for the onset of diabetes.