[Rapid detection of Mycoplasma pneumonia by Loop mediated isothermal amplification [LAMP]]

Background and Objective: Mycoplasma pneumoniae bacteria, is one of the most important factor in causing of respiratory infections. Serological and molecular detection methods have their own limitation. Due to this limitation, the application of these methods in all diagnostic laboratories is not possible. Therefore this study was done to determine the rapid detection of Mycoplasma pneumonia by loop mediated isothermal amplification [LAMP]

Methods: In this descriptive laboratory study, nasopharynx samples were collected from 92 patients with atypical pneumonia. DNA sample were extracted by boiling method. Six specific primer pairs were designed for LAMP technique by primer explorer ver 4 software. LAMP product identified by adding SYBR Green. Limit of detection and specificity tests have been done for optimizing LAMP test and optimized test carry out for each sample

Results: The LAMP test was optimized using the large Bst enzyme fragment at 66 degree temperature for 1 hour. The detection limit of the test obtained 1 CFU and the DNA replication does not observed in non of the examined pathogenic factors. Out of 92 clinical samples using LAMP technique, 73 cases were negative [80%] and 19 cases were positive [20%]

Conclusion: The loop-mediated isothermal amplification technique is simple, convenient and available method for detection of Mycoplasma pneumoniae

[Polymerase chain reaction versus conventional laboratory methods in the diagnosis of fungal keratitis]

To compare the value of conventional laboratory methods and polymerase chain reaction [PCR] in the diagnosis of fungal keratitis. This cross sectional study was conducted at Khalili Hospital, Shiraz, Iran. Samples were taken from thirty-eight patients with findings suspicious for fungal keratitis. Corneal scrapings were used for Gram, Giemsa and KOH stains, culture and PCR analysis. Of 38 enrolled eyes, 25 eyes [68.5%] were judged to have fungal infection based on positive cultures, staining, PCR or response to antifungal treatment. PCR detected fungi DNA in 17 of 25 samples [68% sensitivity]. Staining [Gram, Giemsa and KOH] and culture yielded a positive result in 40% and 24% of samples respectively. Twenty one [84%] of 25 patients showed fungal elements in at least one laboratory work up and 4 patients were diagnosed as fungal keratitis only based on response to antifungal drugs. Compared to conventional laboratory methods, PCR based methods offer higher sensitivity and a faster diagnosis in fungal keratitis