فهرست نشریات علمی دسترسی آزاد ایران

Background: As a major pathogen, Streptococcus pneumoniae is responsible for fatal diseases and is deemed to be a major public health problem in the developing countries. Due to its high mortality rate, rapid detection of pneumococci is necessary in medical centers with limited equipment. Loop-mediated isothermal amplification (LAMP) assay is a rapid method to detect bacterial pathogens. Herein, the current study developed a LAMP assay based on the choline-binding protein M ( cbpM ) gene to detect pneumococci isolates. Methods: A set of 4 primers was designed using the sequence of cbpM , and a LAMP assay was conducted using a different ratio of inner primers to outer primers, dNTPs, and MgSO 4 concentrations. The sensitivity of assays was calculated according to 30 clinical isolates of S. pneumoniae . The specificity of primers was also evaluated using 7 non-pneumococcal species. The detection limits of the LAMP assay were also compared with those of the polymerase chain reaction (PCR) assay using a 10-fold serial dilution of the DNA. Results: Optimal temperature and time for the LAMP assay were 62°C and 1 hour, respectively. Its detection limit was only 5 copies of DNA, compared to 50 copies for PCR. When LAMP was tested on 7 non-pneumococcal species, no amplification was observed. Similar to PCR, all 30 S. pneumoniae isolates were detected using the LAMP assay, which showed 100% sensitivity. Conclusions: The LAMP assay is a favorable tool for the rapid detection of pneumococci, and can be employed in medical centers with limited equipment.