The role of enteric viruses in poult enteritis
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Transcript The role of enteric viruses in poult enteritis
Dr. Naresh Jindal
College of Veterinary Sciences
Lala Lajpat Rai University of Veterinary and Animal
Sciences, Hisar -125 004 (INDIA)
Introduction
Clinical
findings
Necropsy findings
Present situation
Economic losses
Future research
Enteritis is an infectious multifactorial disease
of young chicks with clinical signs of diarrhea,
depression, lethargy and gross lesions of pale
intestines and/or ceca with watery contents.
Runting stunting syndrome (RSS)
Maldigestion syndrome
Malabsorption syndrome
Infectious stunting syndrome
Helicopter syndrome
Turkeys
Poult enteritis complex
Poult enteritis syndrome
Poult enteritis mortality syndrome
Light turkey syndrome
Multifactorial
Bacteria:
◦ Salmonella
◦ Escherichia coli
◦ Enterococcus
◦ Clostridium
Protozoa:
o Coccidia and Cryptosporidia
Viruses
RNA
- Rotavirus (RV)
- Reovirus (ARV)
- Astrovirus (AstV)
- Picornavirus
- Picorna-like virus
DNA
-Adenovirus (CAdV)
- Parvovirus (CPV)
Reovirus
- Pathogenic and non-pathogenic
- Limited homology with turkey isolates
Rotavirus
- Group A: Mammals and birds
- Group D: Exclusive to birds
Astrovirus
- Avian nephritis virus (ANV)
- Chicken astrovirus (CAstV)
- Turkey astrovirus-1 (TAstV-1) & -2 (TAstV-2)
Picornavirus
- Cause transmissible viral proventriculitis
Adenovirus
- Ubiquitous in all avian species
Parvovirus
- Induces RSS in broilers
- Important determinant in the complex etiology
of enteric diseases of poultry
RNA viruses
are unstable
Mutation and recombination are common
Genotype – serotype – pathotype
Differences
in antigenicity and pathogenicity:
◦ Disease presentation
◦ Problems for diagnosis
◦ Epidemiology
◦ Potential vaccines
Watery
faeces
Pasty vent
Poor growth / retarded feather development
Lameness in some of the affected birds
Mortality
Pasty vent
Watery feaces
Pale and thin-walled intestines
Watery and frothy intestinal contents
Distended caeca with watery and foamy
contents
Watery contents
Gross lesions- Duodenum
▪ Undigested feed
▪ Erythema of villi
▪ Watery contents
▪ Undigested feed
▪ Increased mucus
USA
CAstVs
in 86% (19/22) of the samples (PantinJackwood et al., 2006)
43
commercial broiler chicken flocks
Astroviruses detected in 86% of the flocks
(Pantin-Jackwood et al., 2008)
Occurrence of various pathogens in PESaffected flocks (n=151)
Pathogen
Rotavirus
Small round virus
Reovirus
Adenovirus
Salmonella
E. coli
Enterococcus
Eimeria
Unknown
No. (%) of PES flocks
73 (48)
26 (17)
1 (0.6)
1 (0.6)
85 (56)
54 (36)
16 (11)
44 (29)
9 (6)
Jindal et al. (2009).
Detection of enteric viruses from poult enteritis
syndrome (PES)-affected cases
Method
EM
RT-PCR
Number (%) of cases positive for
Rotavirus
TAstV-2/SRV1
Reovirus
25 (58)
13 (30)
0
40 (93)
36 (84)
17 (40)
TAstV-2 = turkey astrovirus-2 (detected by RT-PCR); SRV = small round viruses
(detected by electron microscopy).
EM = electron microscopy; reovirus and coronavirus were not detected in any of the
PES cases by EM.
RT-PCR = reverse transcription-PCR; none of the PES cases were positive for
coronavirus by RT-PCR.
Jindal et al. (2010)
Detection of enteric viruses alone or in
combination from poult enteritis syndrome
(PES)-affected cases
Method
EM
RT-PCR
Number (%) of cases positive for
1 virus
2 viruses
3 viruses
16 (59)
11 (41)
0
8 (19)
20 (46)
15 (35)
TAstV-2, Rotavirus or reovirus alone or in combination
None of the PES cases were positive for coronavirus by RT-PCR.
Jindal et al. (2010)
-
-
Tested 34 commercial flock (2010 and 2012)
85.3% flocks positive for enteric viruses
Detected combinations of two or more
enteric viruses simultaneously in 51.7% of
enteric virus-positive chicken farms
ANV, CAstV, RV, ARV major enteric viruses
detected
(Koo et al., 2013)
280
intestinal contents samples from chicken
111 samples (39.6%) positive for one virus while
115 (41.1%) samples for two or more enteric
viruses
Combination of two viruses detected in 74
samples
ANV, CAstV, RV, FAdV, and ARV were the
major viruses detected
(Mettifogo et al., 2014)
India
- Intestinal contents from 65 enteritis-affected chicken
flocks (2014-2015) were examined.
- Samples collected from birds of 1-3 weeks of age.
Pathogen(s)
CAstV alone
ANV alone
CAstV + ANV
Total
Number (%) of samples positive for
indicated viruses
31 (47.69)
04 (6.15)
26 (40.98)
61 (93.84)
All samples were negative for ARV and RV
CAstV/22330/2014/HR(India)/Chicken_(KT386334)
CAstV/23724/2014/HR(India)/Chicken_(KT386336)
CAstV/1089/14/HR(India)/Chicken_(KT386338)
CAstV/22397/2014/HR(India)/Chicken_(KT386332)
CAstV/23893/2014/HR(India)/Chicken_(KT386327)
CAstV/28828/2014/HR(India)/Chicken_(KT386328)
CAstV/22374/2014/HR(India)/Chicken_(KT386333)
CAstV/22159/2014/HR(India)/Chicken_(KT386335)
CAstV/1105/2014/HR(India)/Chicken_(KT386331)
CAstV/4175/2006/USA/Chicken_(JF832365)
CAstV/GA2011/2007/USA/Chicken_(JF414802)
CAstV/GA-SEP-A364-05/USA/Chicken(DQ324839)
CAstV/1194/2012/HR(India)/Chicken_(KT386329)
CAstV/1125/2014/HR(India)/Chicken_(KT386330)
CAstV/Indovax/APF/1319/2013/India/Chicken(KC865608)
CAstV/Indovax/EI/1078/2013/India/Chicken(KC855215)
CAstV/PDRC/588/North_zone/2011/India/Chicken(JX945881)
CAstV/PDRC/447/South_zone/2012/India/Chicken(KC633178)
CAstV/Indovax/SH/1079/2013/India/Chicken(KC855214)
CAstV/PDRC/1803/South_zone/2012/India/Chicken(KC633179)
CAstV/PDRC/580/West_zone/2011/India/Chicken(JX945880)
CAstV/PDRC/579/West_zone/2011/India/Chicken(JX945879)
CAstV/USP358-4/2009/Brazil_(GU014472)
CAstV/USP337-2/Brazil/2009/Brazil/Chicken(GU585496)
CAstV/USP238-1/2010/Brazil/Chicken(JF309118)
CAstV/USP388-3/2010/Brazil/Chicken(JF309117)
CAstV/GA-SEP-A368-05/USA/Chicken(DQ324842)
CAstV/PDRC/1804/South_Zone/2012/India/Chicken(KC633180)
CAstV/PDRC/589/North_zone/2011/India/Chicken(JX945882)
CAstV/23324/2014/HR(India)/Chicken_(KT386337)
CAstV/PDRC/200/East_zone/2011/India/Chicken_(JX945868)
CAstV/325004/2008/Italy/Chicken(JN048401)
CAstV/327845-1/2008/Italy/Chicken(JN048402)
CAstV/324595/2008/Italy/Chicken(JN048391)
CAstV/324996-4/2008/Italy/Chicken(JN048400)
CAstV/ADL122057/2012/S.Korea/Chicken(KC593414)
CAstV/ADL102655-1/2010/S.Korea/Chicken(JN635502)
CAstV/ADL110638/2011/S.Korea_(KC593405)
CAstV/CAstV/CRO-443/2011/Croatia/Duck(JQ946070)
CAstV/MO-SEP-A799-05/2005/USA/Chicken(DQ324850)
CAstV/GA-SEP-A792-05/USA/Chicken(DQ324849)
CAstV/_GA-SEP-A450-05/2005/USA/Chicken(DQ324844)
CAstV/DE-SEP-A654-05/USA/Chicken(DQ324848)
CAstV/ADL121238/2012/S.Korea/Chicken(KC593413)
CAstV/11672/2004/UK/Chicken_(EU668998)
CAstV/324169/2008/Italy/Chicken_(JN048393)
Gp I
Gp II
Gp III
0.05
Phylogenetic analysis based on polymerase
gene of chicken astrovirus
Amino acid changes in polymerase gene
of chicken astrovirus
Amino acid
from
Amino acid to
Position No. of strains
showing the
change
Isoleucine
Lysine
Valine
Aspartic acid
256
257
9/12
8/12
Valine
Leucine
Glycine
Glutamic acid
262
310
2/12
3/12
Serine
Phenylalanine
330
3/12
Glycine
Cysteine
331
2/12
Sichuan80/2011_(HQ603055)
Sichuan87/2011_(HQ603056)
2009/Sichuan_(HM029238)
255554-3/2009_(JN048380)
ADL120915/2012_(KC593401)
ADL110638/2011_(KC593390)
ADL120886/2012_(KC593400)
ANV/1043/2014/HR(India)/Chicken_(KT376414)
GA-CK-SEP/364-2005_(HQ188698)
GA-CK-SEP/451-2005_(HQ188696)
ADL111234/2011_(KC593391)
DE-CK-SEP/811-2005_(HQ188693)
GA-CK-SEP/458-2005_(HQ188699)
ANV/1105/2012/HR(India)/Chicken_(KT376416)
ANV/1301/2015/HR(India)/Chicken_(KT376415)
ANV/22392/2014/HR(India)/Chicken_(KT376412)
ANV/1102/2012/HR(India)/Chicken_(KT376419)
ANV/22999/2014/HR(India)/Chicken_(KT376411)
ANV/22766/2014/HR(India)/Chicken_(KT376413)
ANV/1059/2011/HR(India)/Chicken_(KT376417)
ANV/1065/2014/HR(India)/Chicken_(KT376418)
GA/SEPA368/05/2010_(HM017850)
CRO-799/2011_(JQ692619)
VIC3b/2010_(KM985697)
NSW4/2010_(HM017855)
VIC-4a/2010_(KM985694)
NSW3/2010_(HM017854)
VIC-6a/2010_(KM985702)
VIC-5c/2010_(KM985701)
VIC-5b/2010_(KM985700)
G4260/1999_(AB033998)
NSW_1a_(KM985690)
TK/G145/08/2008_(HQ317722)
NC-TK-SEP/537-2005_(HQ188695)
NC-TK-SEP/670-2005_(HQ188697)
0.02
Phylogenetic analysis based on
polymerase gene sequences of ANV
Amino acid changes in polymerase gene
of avian nephritis virus
Amino acid
from
Amino acid to Position No. of ANV
strains
showing the
change
Arginine
Threonine
Arginine
Phenylalanine
Tryptophan
Alanine
Lysine
Valine
1271
1289
1302
1347
8/9
8/9
2/9
8/9
Viral load
- Conducted a study in five breeder flocks
- Flocks sampled for nine weeks
- Maximum viral load upto 3 weeks of age
1
2
3
4
5
6
Age in weeks
Jindal et al. (2011)
Economic losses
Estimated losses from growth depression due
to poult enteritis between US$300 and US$400
million annually considering 10% -15%
growth depression throughout the turkey
industry in the US
(Barnes et al., 2000)
Experimental
studies revealed growth
depression upto 31% in turkey poults
(Jindal et al., 2009, 2010)
Economic losses contd…
20000
birds broiler chicken farm
Necrotic enteritis resulted in a 12% reduction in
body weight and a 10.9% increase in feed
conversion ratio compared to healthy birds
Final body weights ranged from 4.63 to 7.94 lb
Loss to producer ranged from US$878.19 to
US$1480.52 per flock due to weight loss
Increased feed cost ranged from US$370.49 to
US$739.38 per flock
( Skinner et al., 2010)
Second
largest egg (65 billion eggs) and third largest
broiler chicken meat (3.8 million tonnes) producer in
the world as in 2015.
Market is estimated to be worth about Rs 90,000 crore
(equal to 900 billion USD).
By 2016 total chicken meat consumption forecast at
4.19 million tons, up by approximately 8% over 2015.
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Experimental reproduction of the disease
Surveillance studies
NGS study
Potential pathogens and viral interactions
Economic losses
Prevention and control measures
1.Prof. Sagar M. Goyal
2.Dr. Andre F. Ziegler
3.Dr. Devi P. Patnayak
4.Dr. Sunil K. Mor
5. Dr. Babita Kaithal
6. Dr. Pawan Bagri