RESUMO
Background: Systemic fungal infection remains a major cause of morbidity and death in patients undergoing treatment for cancer. Therefore sensitive, quick and inexpensive testes essential for diagnosing systemic fungal infecton. In our labs we commonly diagnose fungemia using convential blood culture. Convential blood culture is time-consuming and with poor sensitivity. Polymerase chain reaction [PCR] has the potential to provide a quick and inexpensive method for diagnosis of systemic fungal infection. We studied these two different methods in the diagnosis of systemic fungal infection. Aim : The aims of this study were to compare convential blood culture and PCR in the diagnosis of systemic fungal infection and to determine sensitivity, specificity of PCR
Methods: Blood samples were collected from patients in Oncology center clinically suspected of systemic fungal infection. Whole blood samples were collected. First part of the sample was inoculated into blood culture bottle and the other part of the sample was subjected to DNA extraction and PCR which was carried out using pan-fungal primers
Results: One hundred thirty three samples were collected. Seventy six positive samples were positive by conventional blood culture bottle and/or PCR. Nine samples were positive by conventional blood culture. They yielded Candida species, these samples were also positive by PCR. The other 67 samples were positive by PCR reaction only using panfungal primer. The most common isolated organisms by conventional blood culture bottle were Candida albicans six isolates [66.7%]. Three non albicans Candida isolates [C. tropicalis, C. krusi and C. dubliniensis] were isolated. Using blood culture as gold test, sensitivity of PCR was 100%, and specificity was 46%. The most common underlying malignancy was leukaemia [84.2%], followed by lymphoma [13.1%], and solid tumours [2.6%]
Conclusion: The application of PCR technology directly to the whole blood samples will allow early and accurate diagnosis of systemic fungal infection?