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J Clin Microbiol. 2015 Feb 18. pii: JCM.02941-14. [Epub ahead of print]
Efficient isolation of swine influenza viruses by age-targeted specimen collection.
Ozawa M1, Matsuu A2, Yonezawa K3, Igarashi M4, Okuya K5, Kawabata T6, Ito K4, Tsukiyama-Kohara K7, Taneno A8, Deguchi E9.
Author information
Abstract
The control of swine influenza virus (SIV) infection is paramount in view of increasing the productivity of pig farming and minimizing the threat of pandemic outbreaks. Thus, SIV surveillance should be conducted by region and on a regular basis. Here, we established a microneutralization assay specific for SIV seroprevalence surveillance by using reporter gene-expressing recombinant influenza viruses. A growth-based SIV seroprevalence revealed that most sows and piglets were positive for neutralizing antibodies against influenza viruses. By contrast, the 90-day-old growing pigs exhibited limited neutralizing activity in their sera, suggesting that this particular age of population is most susceptible to SIV infection, and thus an ideal age group for SIV isolation. From nasal swab specimens of healthy pigs in this age population, we were able to isolate SIVs at a higher incidence (5.3%) compared with those of previous reports. Nucleotide sequencing and phylogenetic analysis of the HA genes revealed that the isolated SIVs have circulated and evolved in pigs, but not have been recently introduced from humans, implying that a large number of SIV lineages may remain 'undiscovered' in global porcine populations. We offer that the 90-day-old growing pigs-targeted nasal swab collection presented in this study facilitates the global SIV surveillance and contribute to the detection and control of SIV infection.
IMPORTANCE:
Because swine influenza viruses (SIVs) not only cause severe epidemics with the abortions and deaths of pigs, but also have the potential to act as a "mixing vessel" for creating novel pandemic viruses, detection and control of SIVs should contribute to both increasing the productivity of pig farming and to minimizing the threat of influenza pandemic outbreaks. Here, we clarified the age-based SIV seroprevalence in pig populations by means of the efficient and biologically-contained SIV-specific antibody detection assays. We then found the 90-day-old growing pigs are most susceptible to SIV infection, and thus an ideal age group for SIV isolation. We did indeed isolate SIVs from this particular age group with higher incidence than those of previous reports. We propose that the 90-day-old growing pigs-targeted nasal swab collection presented in this study could facilitate the global SIV surveillance, and contribute to the detection and control of SIV infection.
Copyright ? 2015, American Society for Microbiology. All Rights Reserved.
PMID: 25694523 [PubMed - as supplied by publisher]
Efficient isolation of swine influenza viruses by age-targeted specimen collection.
Ozawa M1, Matsuu A2, Yonezawa K3, Igarashi M4, Okuya K5, Kawabata T6, Ito K4, Tsukiyama-Kohara K7, Taneno A8, Deguchi E9.
Author information
Abstract
The control of swine influenza virus (SIV) infection is paramount in view of increasing the productivity of pig farming and minimizing the threat of pandemic outbreaks. Thus, SIV surveillance should be conducted by region and on a regular basis. Here, we established a microneutralization assay specific for SIV seroprevalence surveillance by using reporter gene-expressing recombinant influenza viruses. A growth-based SIV seroprevalence revealed that most sows and piglets were positive for neutralizing antibodies against influenza viruses. By contrast, the 90-day-old growing pigs exhibited limited neutralizing activity in their sera, suggesting that this particular age of population is most susceptible to SIV infection, and thus an ideal age group for SIV isolation. From nasal swab specimens of healthy pigs in this age population, we were able to isolate SIVs at a higher incidence (5.3%) compared with those of previous reports. Nucleotide sequencing and phylogenetic analysis of the HA genes revealed that the isolated SIVs have circulated and evolved in pigs, but not have been recently introduced from humans, implying that a large number of SIV lineages may remain 'undiscovered' in global porcine populations. We offer that the 90-day-old growing pigs-targeted nasal swab collection presented in this study facilitates the global SIV surveillance and contribute to the detection and control of SIV infection.
IMPORTANCE:
Because swine influenza viruses (SIVs) not only cause severe epidemics with the abortions and deaths of pigs, but also have the potential to act as a "mixing vessel" for creating novel pandemic viruses, detection and control of SIVs should contribute to both increasing the productivity of pig farming and to minimizing the threat of influenza pandemic outbreaks. Here, we clarified the age-based SIV seroprevalence in pig populations by means of the efficient and biologically-contained SIV-specific antibody detection assays. We then found the 90-day-old growing pigs are most susceptible to SIV infection, and thus an ideal age group for SIV isolation. We did indeed isolate SIVs from this particular age group with higher incidence than those of previous reports. We propose that the 90-day-old growing pigs-targeted nasal swab collection presented in this study could facilitate the global SIV surveillance, and contribute to the detection and control of SIV infection.
Copyright ? 2015, American Society for Microbiology. All Rights Reserved.
PMID: 25694523 [PubMed - as supplied by publisher]