title: Loop-mediated isothermal amplification assay for the rapid detection of Staphylococcus aureus.
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 10(2) CFU/mL when compared to 12.5 ng/μL and 10(3) 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.
authors.affiliation: Institute of Biological Science, Faculty of Science, University of Malaya, 50603 Kuala Lumpur, Malaysia.
authors.forename: King Ting
authors.initials: KT
authors.lastname: Lim
authors.forename: Cindy Shuan Ju
authors.initials: CS
authors.lastname: Teh
authors.forename: Kwai Lin
authors.initials: KL
authors.lastname: Thong
mesh_terms: D017931:DNA Primers / Q000235:genetics; D004269:DNA, Bacterial / Q000235:genetics; D005798:Genes, Bacterial; D006801:Humans; D057230:Limit of Detection; D055624:Methicillin-Resistant Staphylococcus aureus / Q000235:genetics; D021141:Nucleic Acid Amplification Techniques / Q000379:methods*; D016133:Polymerase Chain Reaction / Q000379:methods*; D011237:Predictive Value of Tests; D012680:Sensitivity and Specificity; D013203:Staphylococcal Infections / Q000175:diagnosis; D013211:Staphylococcus aureus / Q000235:genetics / Q000302:isolation & purification*; D013234:Stem Cells
chemical_list: D017931:DNA Primers; D004269:DNA, Bacterial