Evaluation of two multiplex RT-PCR assays for detection and subtype differentiation of Brazilian swine influenza viruses.
Braz J Microbiol
; 51(3): 1447-1451, 2020 Sep.
Article
in En
| MEDLINE
| ID: mdl-32125678
ABSTRACT
Influenza A virus (IAV) subtypes H1N1, H1N2, and H3N2 are endemic in swine herds in most pork producing countries; however, the viruses circulating in different geographic regions are antigenically and genetically distinct. In this sense, the availability of a rapid diagnostic assay to detect locally adapted IAVs and discriminate the virus subtype in clinical samples from swine is extremely important for monitoring and control of the disease. This study describes the development and validation of a multiplex RT-PCR assay for detection and subtyping of IAV from pigs. The analytical and diagnostic specificity of the assays was 100% (94.3-100.0, CI 95%), and the limit of detection was 10-3 TCID50/mL. A total of 100 samples (IAV isolates and clinical specimens) were tested, and the virus subtype was determined for 80 samples (80%; 71.1-86.7, CI 95%). From these, 50% were H1N1, 22.5% were H1N2, and 7.5% were H3N2. Partial subtyping was determined for 8.75% samples (H1pdmNx and HxN2). Additionally, mixed infections with two virus subtypes (H1N2 + H3N2 and H1N1pdm + H1pdmN2; 2.5%) and reassortant viruses (H1pdmN2, 6.25%; and H1N1hu, 2.5%) were detected by the assay. A rapid detection of the most prevalent IAV subtypes and lineages in swine is provided by the assays developed here, improving the IAV diagnosis in Brazilian laboratories, and contributing to the IAV monitoring.
Key words
Full text:
1
Collection:
01-internacional
Database:
MEDLINE
Main subject:
Swine Diseases
/
Orthomyxoviridae Infections
/
Reverse Transcriptase Polymerase Chain Reaction
/
Influenza A Virus, H1N1 Subtype
/
Influenza A Virus, H3N2 Subtype
/
Influenza A Virus, H1N2 Subtype
/
Multiplex Polymerase Chain Reaction
Type of study:
Diagnostic_studies
/
Evaluation_studies
Limits:
Animals
Country/Region as subject:
America do sul
/
Brasil
Language:
En
Journal:
Braz J Microbiol
Year:
2020
Document type:
Article