Comparison of automated and conventional microbiological examination of donated human cardiac tissue in heart valve banking.

Most tissue banks use the conventional method; however, the automated method has advantages over the conventional method. The aim of this study was to compare the conventional and automated methods of culture in human cardiac tissue using an artificial contamination model. Myocardial samples were contaminated with sequential concentration (10 ⁴ to 10 ^-1  CFU/mL) with Pseudomonas aeruginosa, Escherichia coli, Staphylococcus aureus and Candida albicans. Cultures were obtained from solution were the fragment was immersed and minced tissue, before and after the routine decellularization solution, with automated and conventional culture methods. Automated and conventional methods were compared and a p value ≤ 0.05 was considered significant. Staphylococcus aureus presented a significantly higher growth in the automated method, as well as faster than the conventional (p < 0.05). The positivity for growth in the automated method was higher in concentrated inoculum (> 10 ²  CFU/mL) (p < 0.05). The growth in the automated method was significantly faster than conventional when inoculum concentration was above 10 ³  CFU/mL. The automated culture method is faster than conventional method with a higher positivity in a contaminated model of myocardial and transport solution used in tissue banks.