LOOP mediated isothermal AMPlification (LAMP) in diagnosis of neorocryptococcosis

Abstract

As a result of the importance of quick diagnosis of Neurocryptococcosis in patients, generally, molecular techniques are preferred rather than traditional methods for their rapidity. In this research, we made an effort to design and optimize Loop mediated isothermal AMPlification (LAMP) technique using specific primers for ura5 as the target gene for detection of Cryptococcus neoformans and Cryptococcus gattii beside comparison of this assay with the common molecular technique of polymerase chain reaction (PCR). We collected a quantity of 35 serum samples of HIVpositive patients and a number of 107 cerebrospinal fluid (CSF) samples of patients who had shown symptoms of meningitis. We designed target specific primers for PCR and LAMP techniques to trace C. neoformans and C. gattii. From the total 142 clinical specimens, five had positive results from LAMP technique, that is, two out of 107 CSF samples and three out of 35 serum samples were positive for Cryptococcosis, but all specimens had negative results by PCR technique. According to the results of this research, it is clear that LAMP technique detects the agent faster and its specificity and sensitivity are much higher. Results reveal that LAMP as compared to PCR can find the target even in those samples containing a fewer number of the agents. LAMP is even more beneficial than PCR and it can be applied just using a simple thermal block or water bath. Therefore, we recommend diagnosis of Neurocryptococcosis by using LAMP technique which is useful in clinical and ambulatory laboratories.

Key words: Cryptococcus, Loop mediated isothermal AMPlification (LAMP), neurocryptococcosis, polymerase chain reaction (PCR).