Rapid and specific detection of H3 swine influenza virus using reverse transcription loop-mediated isothermal amplification method.
OBJECTIVE
The main objective of our study is to develop a reverse transcriptase loop-mediated isothermal amplification (RT-LAMP)-based system for rapid and specific detection of H3 swine influenza virus (SIV).


RESULTS
The system, H3 RT-LAMP, contained a set of six novel primers that targeted eight distinct regions of the viral haemagglutinin (HA) gene that are highly conserved among H3 influenza A viruses but not between H3 and other subtypes. H3 RT-LAMP accurately and specifically detected H3 SIV of different isolates from culture and from swine lung samples. The system is at least 10-fold more sensitive than the conventional RT-PCR assay and even comparable to the real-time RT-PCR method, with the detection limit of about one plaque-forming unit per reaction. Of 27 swine lung samples tested, 11 samples were positive in reactions with the RT-LAMP and real-time RT-PCR methods, while only 7 were positive with the conventional RT-PCR assay. Importantly, the assay can be completed within 45 min and is faster than the conventional RT-PCR and real-time RT-PCR approaches.


CONCLUSIONS
Our results provide the first direct evidence that RT-LAMP is highly specific and sensitive for detecting H3 SIV.


CONCLUSIONS
These results suggest that LAMP offers a promising alternative tool for rapid, inexpensive and specific diagnosis of influenza virus infection of swine and other animals in frontline settings.
Gu
H
H
Institute of Virology, State Key Laboratory of Pharmaceutical Biotechnology, School of Life Sciences, Nanjing University, Nanjing, Jiangsu, China.
Qi
X
X
Li
X
X
Jiang
H
H
Wang
Y
Y
Liu
F
F
Lu
S
S
Yang
Y
Y
Liu
F
F
D000818:Animals; D017931:DNA Primers; D009980:Influenza A virus / Q000235:genetics* / Q000302:isolation & purification*; D008168:Lung / Q000821:virology; D021141:Nucleic Acid Amplification Techniques; D009976:Orthomyxoviridae Infections / Q000175:diagnosis / Q000662:veterinary*; D020133:Reverse Transcriptase Polymerase Chain Reaction; D012680:Sensitivity and Specificity; D013552:Swine; D013553:Swine Diseases / Q000175:diagnosis
D017931:DNA Primers