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| Articles
by
M. Asok Kumar |
Total Records (
2 ) for
M. Asok Kumar |
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P. Thomas
,
T.R. Arun
,
K. Karthik
,
P.V. Berin
,
M. Asok Kumar
,
Neetu Singh
,
J. Usharani
,
M. Palanivelu
,
S.K. Gupta
,
K. Dhama
and
K.N. Viswas
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Necrotic enteritis, caused by Clostridium perfringens, is an important
bacterial disease of poultry. A suspected case of necrotic enteritis was presented
for necropsy from an Indian Kadaknath Fowl flock showing diarrhea and progressive
debility. Gross examination revealed necrotic to ulcerative lesions in intestine.
The organism was isolated from the intestinal contents, tissue and liver under
anerobic conditions. The cultural characteristics and Gram staining were suggestive
of C. perfringens. The sequencing of 16s rRNA gene confirmed the isolate
as C. perfringens and which was well differentiated from other clostridia
associated with avian intestinal tract. This study demonstrates that 16s rRNA
gene sequencing can provide rapid and confirmatory identification of C. perfringens.
Further, Multiplex Polymerase Chain Reaction (mPCR) was performed for toxinotyping
and isolate was found to be positive for α toxin (cpa) and β2
toxin (cpb2), a feature of C. perfringens type A isolates. As
some recent studies have highlighted the involvement of NetB toxin in pathogenesis,
therefore, PCR was carried out to find the presence of this toxin, the isolate
was found to be negative for netB gene. This study emphasizes the molecular
characterization and toxinotyping as a rapid tool for detection of C. perfringens
from suspected necrotic enteritis cases. Very few reports regarding molecular
characterization are available from India, hence it adds to the available data
on this important poultry pathogen. Further investigations are required to understand
the exact role of NetB toxin in pathogenesis as various studies including the
current one reports NetB negative strains involved in necrotic enteritis. |
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Kuldeep Dhama
,
Shambhu Dayal Singh
,
Rajamani Barathidasan
,
P.A. Desingu
,
Sandip Chakraborty
,
Ruchi Tiwari
and
M. Asok Kumar
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Growth in poultry sector is being challenged due to increased
incidence and re-emergence of diseases caused due to evolution of several viral
pathogens and use of live vaccines. Piles of economic losses are encountered
due to these diseases. Avian Infectious Bronchitis (IB), caused by Corona
virus, is OIE-listed disease and characterized by respiratory, renal and
urogenital involvements, causing high mortality. Economic losses are encountered
due to loss of productive performance of both egg and meat-type chickens. Variant
viruses evolve due to spontaneous mutations and recombinations, causing disease
in vaccinated flocks of all ages. Serotyping and genotyping are the common methods
of classification of IBV strains. The virus has 4 clusters, grouped into 7 serotypes
and the most important strains are Massachusetts, Connecticut, Arkansas, Gray,
Holte and Florida along with numerous others, distributed round the globe. Several
conventional and molecular diagnostic methods have been described for the diagnosis
of IB in chickens. 'All-in/all-out' operations of rearing along with good biosafety
measures forms the basis of prevention, whereas vaccination forms the backbone
of IB control programme. Both live and inactivated (oil emulsified) conventional
vaccines are available. The new generation vaccines (recombinant and vector-based)
developed against locally prevailing IBV strains may be more helpful and avoid
the reversion of virulence in live vaccine viruses. The present review deals
with all these perspectives of this important emerging poultry pathogen. |
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