Publications (49)78.05 Total impact
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Article: Isolation and characterization of influenza A virus (subtype H5N1) that caused the first highly pathogenic avian influenza outbreak in chicken in Bhutan.
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ABSTRACT: We characterized Influenza A/H5N1 virus that caused the first outbreak of highly pathogenic avian influenza (HPAI) in chickens in Bhutan in 2010. The virus was highly virulent to chicken, killing them within two days of the experimental inoculation with an intravenous pathogenicity index (IVPI) of 2.88. For genetic and phylogenetic analyses, complete genome sequencing of 4 viral isolates was carried out. The isolates revealed multiple basic amino acids at their hemagglutinin (HA) cleavage site, similar to other "Qinghai-like" H5N1 isolates. The receptor-binding site of HA molecule contained avian-like amino acids ((222)Q and (224)G). The isolates also contained amino acid residue K at position 627 of the PB2 protein, and other markers in NS 1 and PB1 proteins, highlighting the risk to mammals. However, the isolates were sensitive to influenza drugs presently available in the market. The sequence analysis indicated that the Bhutan viruses shared 99.1-100% nucleotide homology in all the eight genes among themselves and 2010 chicken isolate from Bangladesh (A/chicken/Bangladesh/1151-11/2010) indicating common progenitor virus. The phylogenetic analysis indicated that the Bhutan isolates belonged to sub-clade 2.2.3 (EMA 3) and shared common progenitor virus with the 2010 Bangladesh virus. Based on the evidence of phylogeny and molecular markers, it could be concluded that the outbreaks in Bhutan and Bangladesh in 2010 were due to independent introductions of the virus probably through migratory birds.Veterinary Microbiology 08/2011; 155(1):100-5. · 3.33 Impact Factor -
Article: Comparison of a nucleoprotein gene based RT-PCR with real time RT-PCR for diagnosis of avian influenza in clinical specimens.
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ABSTRACT: A nucleoprotein (NP) gene based reverse transcription polymerase chain reaction (npRT-PCR) assay was developed in our laboratory which could detect 35.09% of the experimental samples negative for virus isolation in first passage but positive by third passage. Reducing the reaction volume to 12.5 μl did not alter the test sensitivity and the results did not vary when duplicate samples were run in a different thermal cycler. The positive and negative agreements of this test in clinical specimens were compared with a matrix gene based real time RT-PCR with virus isolation as standard. A total of 516 clinical specimens including tissues, swabs and feces submitted from various States of India as part of active surveillance for avian influenza were tested by npRT-PCR, RRT-PCR and virus isolation in 9-11 day old embryonated specific pathogen free chicken eggs. The positive and negative agreements of npRT-PCR with virus isolation were found to be 0.909±0.022 and 0.980±0.004 respectively and that of RRT-PCR with virus isolation were 0.902±0.023 and 0.977±0.005 respectively. Since the positive and negative agreements of both npRT-PCR and RRT-PCR tests were similar, we suggest that this test can be used by peripheral veterinary laboratories that do not have real time PCR facility for active surveillance of AIV.Research in Veterinary Science 06/2011; 93(1):504-7. · 1.65 Impact Factor -
Article: Phylogenetic evidence of multiple introduction of H5N1 virus in Malda district of West Bengal, India in 2008.
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ABSTRACT: Outbreaks of H5N1 avian influenza virus were reported in 15 districts of West Bengal State in India in early 2008 and subsequent re-occurrence in 5 districts in December, 2008 to May, 2009. We have sequenced complete genome of 12 viruses isolated from early 2008 outbreak and from recurrent outbreak and determined the phylogenetic relationship between the viruses isolated from the two outbreaks. One of the virus isolated in early 2008 from Malda district (A/chicken/West Bengal/81760/2008) clustered with Korean and Russian isolates of 2006 in European-Middle Eastern-African (EMA) 3 sub-lineage of sub-clade 2.2, whereas other viruses showed close genetic relationship with 2007-2009 isolates of Bangladesh. Nucleotide sequence analysis revealed that the PB1-F2 protein expression might be completely abolished due to mutated start codon ((95)ATG(97)→(95)ACG(97)) in this isolate but in all other isolates it was completely expressed. Hence, we conclude that there were two separate introductions of H5N1 viruses in Malda district and this H5N1 virus was not epidemiologically dominant as the viruses isolated subsequently from the same district and region did not share close relationship with this virus. The failure of this virus to spread to adjoining areas suggests that the culling and disposal operations initiated by Government of India were effective.Veterinary Microbiology 03/2011; 148(2-4):132-9. · 3.33 Impact Factor -
Article: Genetic characterization of vaccine and field strains of serotype A foot-and-mouth disease virus from India.
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ABSTRACT: Extreme antigenic and genetic heterogeneity of serotype A foot-and-mouth disease virus (FMDV) population has resulted in change of vaccine strains in India twice in the last decade. In such a situation, complete characterization of the vaccine strains is imperative. With regard to the frequent outbreaks of this disease, FMDV field strains are also of interest. Therefore three vaccine strains and two field strains of type A FMDV from India were completely sequenced and the obtained sequences were subjected to sequence and phylogenetic analyses. Based on the complete coding region, all the Indian strains clustered in the Asia topotype and exhibited a more than 11% nt divergence from the other Asian strains. The 5'-UTR of some Indian strains revealed block deletions of 43 and 86 nt corresponding to the pseudoknot region. Amino acids S44 in VP2 and F164 in VP1 were found to be the exclusive signatures for the Asia topotype. The vaccine strains differed at 65 aa positions in the capsid region, 13 of them antigenically critical. Variability at such positions is likely to affect the antigenic profile of these strains. Complete genome sequences of the vaccine strains presented here could serve as the reference for any comparative genomics in future.Acta virologica 01/2011; 55(4):349-52. · 0.68 Impact Factor -
Article: Emergence of amantadine-resistant avian influenza H5N1 virus in India.
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ABSTRACT: This study reports the genetic characterization of highly pathogenic avian influenza (HPAI) virus (subtype H5N1) isolated from poultry in West Bengal, India. We analyzed all the eight genome segments of two viruses isolated from chickens in January 2010 to understand their genetic relationship with other Indian H5N1 isolates and possible connection between different outbreaks. The hemagglutinin (HA) gene of the viruses showed multiple basic amino acids at the cleavage site, a marker for high virulence in chickens. Of greatest concern was that the viruses displayed amino acid substitution from serine-to-asparagine at position 31 of M2 ion channel protein suggesting emergence of amantadine-resistant mutants not previously reported in HPAI H5N1 outbreaks in India. Amino acid lysine at position 627 of the PB2 protein highlights the risk the viruses possess to mammals. In the phylogenetic trees, the viruses clustered within the lineage of avian isolates from India (2008-2009) and avian and human isolates from Bangladesh (2007-2009) in all the genes. Both these viruses were most closely related to the viruses from 2008 in West Bengal within the subclade 2.2.3 of H5N1 viruses.Virus Genes 10/2010; 42(1):10-5. · 1.85 Impact Factor -
Article: Isolation and molecular characterization of a H5N1 virus isolated from a Jungle crow (Corvus macrohynchos) in India.
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ABSTRACT: In 2008, India experienced widespread outbreaks of H5N1 virus in West Bengal, Tripura, and Assam. The virus was detected in Kamrup district of Assam in November 2008 and subsequently spread to eight more districts. Two Jungle or Large billed crows (Corvus macrohynchos) were found dead in a hospital campus at about 8 km from the foci of initial detection of the virus in the same district. One of the crows was positive for H5N1 avian influenza virus by virus isolation, real time RT-PCR, and RT-PCR tests. Full length sequencing of all the eight segments of the virus was carried out. The phylogenetic analysis indicated that all the eight genes grouped with clade 2.2 viruses and were closely related to the human isolate of Bangladesh and avian isolates from India, Bangladesh, Kuwait, Germany, and Saudi Arabia. The molecular analysis indicated avian receptor (alpha 2,3 sialic acid) specificity, susceptibility to oseltamivir and amantadine group of antivirals and lower pathogenicity to mice.Virus Genes 08/2010; 41(1):30-6. · 1.85 Impact Factor -
Article: Influence of dose of inocula on outcome of clinical disease in highly pathogenic avian influenza (H5N1) infections--an experimental study.
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ABSTRACT: Twelve-week-old Vanaraja (an Indian native dual purpose breed) chickens were inoculated intranasally with different doses (100, 1000, and 10,000 mean embryo infective dose [EID50]) of H5N1 virus, and the clinical disease and pathologic changes were compared. Although the overall severity of clinical signs was more severe in the 100 EID50 group, the progression of the clinical disease was slower with delayed onset of mortality when compared with the other two groups. The mean death time of the 100 EID50 group (4.57 days) differed significantly from that of the 10,000 EID50 group (3.60 days) and from that of the 1000 EID50 group (3.33 days). Similarly, overall severity of gross lesions was expressed more in the 100 EID50 group. The histopathologic lesions were of a more hemorrhagic and necrotic nature in the 100 EID50 group, histopathologic lesions were of an inflammatory/proliferative nature in the 1000 EID50 group, and a tendency for intravascular coagulopathy was observed in the 10,000 EID50 group. These differences may be assigned to the influence of dose in the outcome of disease.Avian Diseases 03/2010; 54(1 Suppl):576-80. · 1.46 Impact Factor -
Article: Influence of Dose of Inocula on Outcome of Clinical Disease in High-Pathogenicity Avian Influenza (H5N1) Infections—An Experimental Study
AVIAN DISEASES. 10/2009; 53. -
Article: Avian influenza virus (H5N1) in chickens in India.
The Veterinary record 02/2009; 164(4):128. · 1.25 Impact Factor -
Article: Isolation and pathotyping of H9N2 avian influenza viruses in Indian poultry.
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ABSTRACT: A total of 1246 faecal and tissue samples collected/received from 119 farms located in various states of India were processed for isolation of avian influenza viruses (AIV) during 2003-2004 as part of a program to monitor AIV infection in Indian poultry population. Avian influenza virus was isolated for the first time in India from poultry farms with history of drop in egg production, respiratory illness and increased mortality in Haryana state. A total of 29 H9N2 AIV isolates were obtained from the states of Punjab, Haryana, Uttar Pradesh, Gujarat, and Orissa and Union Territory Delhi. Subtyping was done by HI, RT-PCR and neuraminidase inhibition assay. Pathotyping of six representative isolates by intravenous pathogenicity index (0.0/3.0) in 6-8 weeks old chicken, trypsin dependency in cell culture and HA cleavage site analysis (335RSSR*GLF341) confirmed that these isolates are low pathogenic. Nucleotide sequence analysis of the HA gene showed that the Indian isolates are very closely related (95.0-99.6%) and shared a homology of 92-96% with H9N2 isolates from Germany and Asian regions other than that of mainland China. Deduced amino acid sequences showed the presence of L226 (234 in H9 numbering) which indicates a preference to binding of alpha (2-6) sialic acid receptors. Two of the six isolates had 7 glycosylation sites in the HA1 cleaved protein and the remaining four had 5 sites. Phylogenetic analysis showed that they share a common ancestor Qa/HK/G1/97 isolate which had contributed internal genes of H5N1 virus circulating in Vietnam. Further characterization of Indian H9N2 isolates is required to understand their nature and evolution.Veterinary Microbiology 07/2008; 133(1-2):154-63. · 3.33 Impact Factor -
Article: H5N1 virus outbreaks in poultry in India.
The Veterinary record 03/2008; 162(8):255. · 1.25 Impact Factor -
Article: Genetic analysis of H9N2 avian influenza viruses isolated from India.
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ABSTRACT: H9N2 avian influenza viruses are endemic in domestic poultry in Asia and are grouped into three major sublineages represented by their prototype strains A/Duck/Hong Kong/Y280/97 (Y280-like), A/Quail/Hong Kong/G1/97 (G1-like) and A/Chicken/Korea/38349-p96323/96 (Korean-like). To understand the genetic relationship of Indian viruses, we determined the partial nucleotide sequence of five H9N2 avian influenza viruses isolated from chicken in India during 2003-2004 and compared them with H9N2 sequences available in GenBank. Deduced amino acid sequence analysis revealed that four isolates shared an R-S-S-R/G motif at the cleavage site of HA, representing low pathogenicity in chickens, while one virus harbors an R-S-N-R/G motif at the same position. All the viruses maintained the human-like motif 226Lysine (H3 numbering) at the HA receptor binding site. Phylogenetic analysis showed that 50% of the genes (HA, NA, NP and M) were similar to G1-like viruses, whereas the remaining genes of the Indian isolates formed a separate, not yet defined, sublineage in the Eurasian lineage. Our finding provides evidence of a novel reassortant H9N2 genotype of G1-like viruses circulating in India.Archives of Virology 02/2008; 153(8):1433-9. · 2.11 Impact Factor -
Article: Genetic and antigenic characterization of bovine viral diarrhea virus type 2 isolated from Indian goats (Capra hircus).
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ABSTRACT: Recent studies have shown that bovine viral diarrhea virus (BVDV) type 1 is widely prevalent in Indian cattle. In a surveillance of randomly collected 562 blood samples from seven states during 2004-2006, BVDV type 2 was detected in two native Indian goats by nested reverse transcription polymerase chain reaction (nRT-PCR). The virus isolated from them was classified antigenically as BVDV 2 on the basis of virus neutralization test and reactivity with monoclonal antibodies. Phylogenetic analysis of three different genomic regions, 5' un-translated region (5' UTR), E(rns) structural coding region and NS5B nonstructural coding region typed Indian goat isolate as BVDV 2a having close similarity with strains from North America and Europe suggesting its probable introduction through trade. It was placed in a separate clade within the 2a branch having unique mutations in E(rns) and NS5B region. This is the first report of BVDV 2 in India and only second time recorded in goat species. The isolation of BVDV 2 from goat warrants intensive surveillance in cattle and sheep.Veterinary Microbiology 11/2007; 124(3-4):340-7. · 3.33 Impact Factor -
Article: Outbreak of avian influenza virus H5N1 in India.
The Veterinary record 09/2007; 161(8):279. · 1.25 Impact Factor -
Article: Analysis of the PB2 gene reveals that Indian H5N1 influenza virus belongs to a mixed-migratory bird sub-lineage possessing the amino acid lysine at position 627 of the PB2 protein.
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ABSTRACT: Outbreaks of highly pathogenic avian influenza (HPAI) H5N1 virus were reported for the first time in India during February 2006. Herein, we have sequenced and analyzed the PB2 genes of five influenza virus isolates obtained from three affected states (Gujarat, Madhya Pradesh and Maharashtra) in India during the outbreaks. In the phylogenetic analysis, the Indian isolates were grouped in the mixed-migratory bird sub-lineage of the Eurasian lineage. From the phylogenetic tree, it is evident that viruses were probably introduced to India from China via Europe because they share a direct ancestral relationship with the Indian isolates. The virus might have spread through migratory waterfowls that survived the HPAI H5N1 infection. These viruses were able to replicate in cultured cells of avian and mammalian hosts and posses lysine at position 627 of the PB2 protein, indicating that they might be able to cross the host barrier to infect mammals.Archives of Virology 02/2007; 152(9):1637-44. · 2.11 Impact Factor -
Article: Sequence analysis of the non-structural 3A and 3C protein-coding regions of foot-and-mouth disease virus serotype Asia1 field isolates from an endemic country.
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ABSTRACT: A total of 18 foot-and-mouth disease virus (FMDV) serotype Asia1 field isolates belonging to two different lineages (including the divergent group) as delineated earlier in VP1-based phylogeny were sequenced in the non-structural 3A and 3C protein-coding regions. The phylogenetic trees representing the regions coding for the non-structural proteins were very similar to that of the structural VP1 protein-coding region. Phylogenetic comparison at 3C region revealed clustering of Asia1 viruses with the isolates of serotypes O, A and C in the previously identified clade. Comparison of amino acid sequences identified lineage-specific signature residues in both the non-structural proteins. Overall analysis of the amino acid substitutions revealed that the 3A coding region was more prone to amino acid alterations than 3C region.Veterinary Microbiology 09/2006; 116(1-3):187-93. · 3.33 Impact Factor -
Article: Phylogenetic analysis revealed genetic similarity of the H5N1 avian influenza viruses isolated from HPAI outbreaks in chickens in Maharashtra, India with those isolated from swan in Italy and Iran in 2006
CURRENT SCIENCE,. 07/2006; VOL. 91:77. -
Article: A novel genetic lineage differentiating RT-PCR as a useful tool in molecular epidemiology of foot-and-mouth disease in India.
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ABSTRACT: Comparison of nucleotide sequences at the VP1 coding region of foot-and-mouth disease serotype Asia1 viruses from India has revealed two genetic lineages with emergence of a genetically divergent group in recent years. In this study a simple, fast, relatively costeffective multi-primer RT-PCR assay to differentiate genetic lineages of type Asia1 viruses was developed. Efforts were made in the design of novel lineage-specific primers and in optimization of the multi-primer assay protocol in conjunction with the use of the serotype specific primer for confirmation of serotype Asia1 virus. This assay promises to be an effective tool in molecular epidemiological investigation of FMD in the country.Archives of Virology 05/2006; 151(4):803-9. · 2.11 Impact Factor -
Article: FMD in the Andaman and Nicobar Islands.
The Veterinary record 04/2006; 158(10):347-8. · 1.25 Impact Factor -
Article: Genetic comparison of large fragment of the 5'untranslated region among foot-and-mouth disease viruses with special reference to serotype Asia1.
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ABSTRACT: Foot-and-mouth disease (FMD), the most economically important disease of cloven-hoofed animals, is endemic in India. Sequence analysis revealed that phylogenetic grouping of type Asia1 field isolates on the basis of the large fragment of the 5'untranslated region (5'LF-UTR) was quite similar to that based on the sequences of the capsid-coding (VP1) region of the same viruses. The existence of two distinct lineages of type Asia1 suggested by the study on the VP1 region was further supported by the detection of a difference in length and predicted secondary structure of the 5'LF-UTR between the two lineages. Sequence variability between the isolates of the two lineages was also observed within the different domains of the internal ribosome entry site (IRES) around conserved motifs like the GNRA,- RAAA,- and the polypyrimidine tract. Certain group and lineage-specific signature nucleotides pertaining to FMDV type Asia1 in the 5'LF-UTR have been identified. The present study shows that the 5'LF-UTR of FMDV serotype Asia1 field isolates are variable in relation to the length and probable secondary structure of the IRES.Archives of Virology 12/2005; 150(11):2217-39. · 2.11 Impact Factor
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1997–2010
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Indian Veterinary Research Institute
- High Security Animal Disease Laboratory
Bareilly, Uttar Pradesh, India
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