Genetic analysis of HA gene of pandemic H1N1 2009 influenza viruses circulating in India

Gunasekaran, Palani; Krishnasamy, Kaveri; Arunagiri, Kavita; Sambasivam, Mohana; Lakshmipathy, M; Arunpon,; Fathima, S G

doi:10.4103/0255-0857.99500

Cited by 3 publications

(1 citation statement)

References 18 publications

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“…during August and September months. Upsurge of cases are reported during the rainy season (monsoon) (Gunasekaran et al, 2012). JE cases started reporting during the months of April -May and reaching peak during late August to early September and subsequently decline from October (Ree and Hwang, 2000).…”

Section: Discussionmentioning

confidence: 99%

Determination of critical density in Culex tritaeniorhynchus Giles, 1901 (Diptera: Culicidae) as a deciding factor influencing the transmission of Japanese encephalitis virus in southern India

Samuel,

Thenmozhi,

Nagaraj

et al. 2016

Entomon

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Japanese encephalitis virus (JEV) causes a severe neurobiological health hazard, namely, Japanese encephalitis (JE) which has been rampant in Cuddalore district in the 1970s and 1980s, transmitted mainly by Culex tritaeniorhynchus. The authors have been working on various aspects of transmission dynamics of JE in Cuddalore district, south India, for past more than two decades and have analyzed varied data on ecology and biology of vector Cx. tritaeniorhynchus, to develop a model for depicting the critical density which is a primary requisite to develop control strategy against vector. Such a model of critical density for the vector will be helpful to forecast prospective outbreaks of the disease exacting heavy morbidity and mortality in many parts of India.

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Section: Discussionmentioning

confidence: 99%

Determination of critical density in Culex tritaeniorhynchus Giles, 1901 (Diptera: Culicidae) as a deciding factor influencing the transmission of Japanese encephalitis virus in southern India

Samuel,

Thenmozhi,

Nagaraj

et al. 2016

Entomon

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Molecular characterization of circulating pandemic strains of influenza A virus during 2012 to 2013 in Lucknow (India)

et al. 2014

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The pandemic H1N1 strain of Influenza A virus [A(H1N1)pdm09] is now well adapted in human populations. However, it is still causing sporadic outbreaks worldwide with different severity. The present study was planned to understand the genetic diversity (based on the HA1 gene) of influenza A(H1N1)pdm09 strains circulating during the post pandemic period. The HA1 gene was selected because the HA1 protein is immunogenic, functions as a receptor binding site and indirectly affects transmission and pathogenicity of virus. A total of 2,818 cases were enrolled. Nasal/throat swabs from all cases were tested by one-step real time PCR for detection of influenza virus types and subtypes according to the CDC protocol. Of these, 134 cases were A(H1N1)pdm09 positive, 34 of which were screened for HA1 gene (position 434-905) sequencing (Big-Dye terminator using 3130 ABI, Genetic analyzer). Molecular and phylogenetic analysis was performed using PhyML approach (v. 3.0). All A(H1N1)pdm09 positive and negative cases were clinically characterized. Phylogentically, all Lucknow strains (n = 33) except one fall with the clade seven reference strain. One strain showed 99.9% similarities with clade one reference strain A/California/07/2009. In mutational analysis, 33 strains had the S220T mutation, which is at an antigenic site and characteristic of clade seven along with few minor mutations; K180I/T/Q, V190I, S200P, S202T, A203T, A214T, S220T, V251I, and A273T. These results suggest that clade seven was the most widely circulating clade in Lucknow and A(H1N1)pdm09 cases showed mild clinical symptoms as compared to A(H3N2) or influenza B cases.

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Genetic Characterization of Influenza A (H1N1) Pandemic 2009 Virus Isolates from Mumbai

Gohil

Kothari

Shinde³

et al. 2017

Curr Microbiol

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Pandemic influenza A (H1N1) 2009 virus was first detected in India in May 2009 which subsequently became endemic in many parts of the country. Influenza A viruses have the ability to evade the immune response through its ability of antigenic variations. The study aims to characterize influenza A (H1N1) pdm 09 viruses circulating in Mumbai during the pandemic and post-pandemic period. Nasopharyngeal swabs positive for influenza A (H1N1) pdm 09 viruses were inoculated on Madin-Darby canine kidney cell line for virus isolation. Molecular and phylogenetic analysis of influenza A (H1N1) pdm 09 isolates was conducted to understand the evolution and genetic diversity of the strains. Nucleotide and amino acid sequences of the HA gene of Mumbai isolates when compared to A/California/07/2009-vaccine strain revealed 14 specific amino acid differences located at the antigenic sites. Amino acid variations in HA and NA gene resulted in changes in the N-linked glycosylation motif which may lead to immune evasion. Phylogenetic analysis of the isolates revealed their evolutionary position with vaccine strain A/California/07/2009 but had undergone changes gradually. The findings in the present study confirm genetic variability of influenza viruses and highlight the importance of continuous surveillance during influenza outbreaks.

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Genetic analysis of HA gene of pandemic H1N1 2009 influenza viruses circulating in India

Cited by 3 publications

References 18 publications

Determination of critical density in Culex tritaeniorhynchus Giles, 1901 (Diptera: Culicidae) as a deciding factor influencing the transmission of Japanese encephalitis virus in southern India

Determination of critical density in Culex tritaeniorhynchus Giles, 1901 (Diptera: Culicidae) as a deciding factor influencing the transmission of Japanese encephalitis virus in southern India

Molecular characterization of circulating pandemic strains of influenza A virus during 2012 to 2013 in Lucknow (India)

Genetic Characterization of Influenza A (H1N1) Pandemic 2009 Virus Isolates from Mumbai

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