Browsing by Author "Karthik, Kumaragurubaran"
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ArticleItem Open Access Emergence of Moraxella bovoculi Associated with Keratoconjunctivitis in an Organized Dairy Farm of India(Council of the National Academy of Sciences, 2017-05) Karthik, Kumaragurubaran; Mahaprabhu, Ramalingam; Roy, Parimal; Raman, Muthusamy; TANUVASAn investigation was carried out in an organized dairy farm of Tamil Nadu State, India where cattle were reported to have eye infection. Preliminary clinical intervention revealed that the animals had infectious bovine keratoconjunctivitis (IBK). Isolation and identification of pathogen from eye swab revealed the presence of Moraxella spp. On further molecular characterization by Polymerase chain reaction (PCR) suggested that the isolate as Moraxella bovoculi. PCR followed by sequencing was carried and the results showed that the isolate was M. bovoculi and the sequencewas submitted in theGenBank with the sequence id. KX121047. Animals were treated with antibiotics as per the results from antibiotic sensitivity test and treatment yielded good results as the animals responded to treatment. This report is the first of its kind fromIndia as therewas no previous report regarding M. bovoculi from the country. Further insights into the bacterial genome can aid in identification of the genes or regions involved in pathogenesis of IBK and also to carve out the prevention and control strategies of IBK.ArticleItem Open Access Haemorrhagic enteritis of turkeys – current knowledge(Taylor and Francis, 2017) Dhama, Kuldeep; Gowthaman, Vasudevan; Karthik, Kumaragurubaran; Tiwari, Ruchi; Sachan, Swati; Kumar, M. Asok; Palanivelu, M.; Malik, Yashpal Singh; Singh, Raj Kumar; Munir, Muhammad; TANUVASHaemorrhagic enteritis virus (HEV), an adenovirus associated with acute haemorrhagic gastrointestinal disease of 6–11-week old turkeys predominantly hampers both humoral and cellular immunity. Affected birds are more prone to secondary complications (e.g. colibacillosis and clostridiosis) and failure to mount an effective vaccine-induced immune response. HEV belongs to the new genus Siadenovirus. Feco-oral transmission is the main route of entry of the virus and it mainly colonizes bursa, intestine and spleen. Both naturally occurring virulent and avirulent strains of HEVs are serologically indistinguishable. Recent findings revealed that ORF1, E3 and fib genes are the key factors affecting virulence. The adoption of suitable diagnostic tools, proper vaccination and biosecurity measures have restrained the occurrence of disease epidemics. For diagnostic purposes, the best source of HEV is either intestinal contents or samples from spleen. For rapid detection highly sensitive and specific tests such as quantitative real-time PCR based on Taq man probe has been designed. Avirulent strains of HEV or MSDV can be effectively used as live vaccines. Novel vaccines include recombinant hexon proteinbased subunit vaccines or recombinant virus-vectored vaccines using fowl poxvirus (FPV) expressing the native hexon of HEV. Notably, subunit vaccines and recombinant virus vectored vaccines altogether offer high protection against challenge or field viruses. Herein, we converse a comprehensive analysis of the HEV genetics, disease pathobiology, advancements in diagnosis and vaccination along with appropriate prevention and control strategies.ArticleItem Open Access Virulence genes and enterobacterial repetitive intergenic consensus region (ERIC) profiling reveals highly diverse genetic population among avian strains of Pasteurella multocida(2021) Karthik, Kumaragurubaran; Prasanna Devi, Rajan; Ananda Chitra, Murugesan, et al.,; TANUVASPasteurella multocida is a multispecies pathogen with certain host specific capsular types but interspecies transmission cannot be overlooked. Knowing the diversity of P. multocida in a geographical location is essential to formulate a vaccination programme. Diversity among the P. multocida isolates from different avian species recovered in the state of Tamil Nadu, India was studied using enterobacterial repetitive intergenic consensus region (ERIC)-PCR and virulence gene profiling (VP). Capsular typing revealed that 44 (97.78%) strains belonged to capsular type A while only one (2.22%) strain belonged to capsular type B. ERIC-PCR analysis showed eight different clusters and four individual strains. The index of discrimination (D value) was found to be 0.8899. Virulence profiling showed that genes fimA, pfhA, hsf-2 and pmHAS were found in 100% of the strains while ompH, omp87, ompA, plpB, sodA, sodC, ptfA, hsf-1, exbB, fur, hgbA and hgbB were found in ≥90% of the strains. Dermonecrotoxin gene toxA was present only in 4.44% of the strains, while nanH in 68.89% and nanB in 88.89% of the strains. One strain each from turkey and Guinea fowl had toxA gene. Correlation analysis revealed a positive correlation between ptfA and hgbA gene, exbB and fur gene, ptfA and sodC gene, exbB and hsf-1 gene, ompA and ompH gene. Majority of duck strains clustered together both in ERIC and virulence gene profiles. Turkey strains were highly diverse with different VPs and ERIC-PCR patterns.