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BioMed Research International
Volume 2013 (2013), Article ID 895816, 5 pages
http://dx.doi.org/10.1155/2013/895816
Research Article

Loop-Mediated Isothermal Amplification Assay for the Rapid Detection of Staphylococcus aureus

1Institute of Biological Science, Faculty of Science, University of Malaya, 50603 Kuala Lumpur, Malaysia
2Laboratory of Biomedical Science and Molecular Microbiology, Institute of Graduate Studies, University of Malaya, 50603 Kuala Lumpur, Malaysia

Received 14 October 2012; Revised 2 January 2013; Accepted 5 January 2013

Academic Editor: Isabel Sá-Correia

Copyright © 2013 King Ting Lim et al. This is an open access article distributed under the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited.

Abstract

Staphylococcus aureus, including methicillin-resistant S. aureus (MRSA), is an important human pathogen that produces a variety of toxins and causes a wide range of infections, including soft-tissue infections, bacteremia, and staphylococcal food poisoning. A loop-mediated isothermal amplification (LAMP) assay targeting the arcC gene of S. aureus was developed and evaluated with 119 S. aureus and 25 non-S. aureus strains. The usefulness of the assay was compared with the PCR method that targets spa and arcC genes. The optimal temperature for the LAMP assay was 58.5°C with a detection limit of 2.5 ng/μL and 102 CFU/mL when compared to 12.5 ng/μL and 103 CFU/mL for PCR (spa and arcC). Both LAMP and PCR assays were 100% specific, 100% sensitive, 100% positive predictive value (PPV), and 100% negative predictive value (NPV). When tested on 30 spiked blood specimens (21 MRSA, eight non-S. aureus and one negative control), the performance of LAMP and PCR was comparable: 100% specific, 100% sensitive, 100% PPV, and 100% NPV. In conclusion, the LAMP assay was equally specific with a shorter detection time when compared to PCR in the identification of S. aureus. The LAMP assay is a promising alternative method for the rapid identification of S. aureus and could be used in resource-limited laboratories and fields.