Contemporary methods for detection of microbial infections in transplanted tissues.

Infective processes developing after transplantation are diagnosed mainly in the specimens harvested from blood and exudates. Not much attention has been focused on identification of microorganisms present in the graft or penetrating the graft from the recipient. Although a progress has been made with respect to detection of viruses there is still little knowledge on the pathological role of bacteria, transplanted together with the graft or acquired from the recipient, in evoking or enhancing the rejection reaction (heterologous immune response). Recently developing molecular techniques allow us to detect bacterial genetic materials in clinical specimens. This article reviews commonly used methods for detection, identification and typing bacterial pathogens. It focuses on specific and universal methods based on gene sequencing, PCR and techniques based on polymorphic DNA. We also present the examples of genes and microorganisms analysed in laboratories. Together with conventional microbiological methods the molecular tests can serve as a key for better understanding the bacterial presence in tissues, not necessarily causing inflammation, quite often being commensal, but also evoking host reaction under certain so far not defined circumstances.