Objective:To demonstrate seroprevalence of avian invluenza(H9N2)subtybe in broiler chickens in Northwest of Iran.Materials:A total of 310 blood samples were collected from 25 broiler flocks in slaughterhouses of West ...Objective:To demonstrate seroprevalence of avian invluenza(H9N2)subtybe in broiler chickens in Northwest of Iran.Materials:A total of 310 blood samples were collected from 25 broiler flocks in slaughterhouses of West Azarbayjan,Iran.Serum samples were subjected to haemagglutination inhibition test.Results:The test showed 40.6%of positive serums.Mean antibody titer of avian influenza virus differed between geographical locations in this survey.Conclusions:High prevalence of avian influenza virus antibodies in serum of birds emphasize that avian influenza has an important role in respiratory complexes in broiler chickens in this region,and probably throughout Iran.Biosecurity measures,monitoring and surveillance programs,and to some degree vaccination are effective tools to prevent introduction of H9N2infection and its economic losses.展开更多
We examined 50 Escherichia coli (E. coli) strains isolated from broiler chickens between January 2013 to March 2014 in order to evaluate the epidemiological prevalence of avian pathogenic E. coli (APEC) in Jordan by m...We examined 50 Escherichia coli (E. coli) strains isolated from broiler chickens between January 2013 to March 2014 in order to evaluate the epidemiological prevalence of avian pathogenic E. coli (APEC) in Jordan by multiplex PCR and random amplification of polymorphic DNA (RAPD) tests. The multiplex polymerase chain reaction (PCR) which was used as tentative criteria of APEC targets 8 virulence associated genes;enteroaggregative toxin (astA), Type 1 fimbria adhesion (fimH), iron-repressible protein (irp2), P fimbriae (papC), aerobactin (iucD), temperature-sensitive hemagglutinin (tsh), vacuolating autotransporter toxin (vat), and colicin V plasmid operon (cva/cvi) genes. The number of detected genes could be used as a reliable index of their virulence. E. coli strains already typed as an APEC always harbor 5 to 8 genes, but non-APEC strains harbor less than 4 genes. Assuming the criteria of an APEC is possession of 5 or more virulence associated genes;we found that all 50 E. coli strains were classified as APEC strains. The RAPD analysis showed that the E. coli strains could be grouped into 35 of RAPD types by using these two different RAPD primer sets, RAPD analysis primer 4 5'AAGAGCCCGT5', and RAPD analysis primer 6 5'CCCGTCAGCA3'. The current study confirmed the endemic nature of APEC in broiler flocks in Jordan. It is essential that the biosecurity on poultry farms should be improved to prevent the introduction and dissemination of APEC and other agents. Furthermore, farmers need to be educated about the signs, lesions, and the importance of this agent.展开更多
Low pathogenic Avian Influenza (AI) virus has the ability to evolve to high pathogenic viruses resulting in significant economic losses in the poultry sector. This study aims at assessing the impact of H9N2 viral pass...Low pathogenic Avian Influenza (AI) virus has the ability to evolve to high pathogenic viruses resulting in significant economic losses in the poultry sector. This study aims at assessing the impact of H9N2 viral passaging in broilers and its relatedness to pathogenicity and amino acid (a.a) sequences of the hemagglutinin (HA) cleavage site and neuraminidase (NA) stalk. The original H9N2 AI virus (P0) was used to challenge ten-21 days old broilers. Individual recovery of H9N2 virus from homogenates of trachea, lungs and airsacs was attempted in 9 days old chicken embryos, as a conclusion of the first passage (P1). Tracheal isolates of H9N2 were passaged for a second (P2) and a third (P3) time in broilers, followed by a similar embryonic recovery procedure. The a.a. sequence of a part of HA1 cleavage site and Neuraminidase stalk were compared among the differently passaged viruses;an assessement of the relatedness of the determined a.a. sequences to the pathogenicity in broilers, based on frequency of mortality, morbidity signs, gross and microscopic lesions at 3 days post challenge with the P1, P2, and P3-H9N2, is concluded. An increase in certain morbidity signs and specific lesions was observed in P2- and P3-H9N2 challenged broilers compared to birds challenged with P1-H9N2. A conserved R-S-S-R amino acid sequence at the HA1 cleavage site was observed in the differently passaged H9N2, associated with a variability in the NA stalk-a.a sequences. The passaging of the low pathogenic H9N2 virus in broilers leads to a trend of increase in pathogenicity, manifested in higher frequency of morbidity signs, and of specific gross and microscopic lesions of the examined organs. This passaging was associated with a conserved a.a. sequence of the hemaglutinin cleavage site and a variability in the sequence of the neuraminidase stalk. A detailed study of the potential of the detected variability in the neuraminidase stalk of H9N2 in induction of a higher pathogenicity in broilers will be the subject of future investigations.展开更多
Highly pathogenic avian influenza （HPAI） contamination via wild birds and rodents poses a threat to food security and safety. As chicken meat comprises an increasing proportion of diet in China, it is useful to dete...Highly pathogenic avian influenza （HPAI） contamination via wild birds and rodents poses a threat to food security and safety. As chicken meat comprises an increasing proportion of diet in China, it is useful to determine whether broiler farmers are adopting wild bird and rodent controls to minimize the risk of HPAI impacts on food supply. Our study surveyed a cross sectional sample of 331 Chinese broiler farmers in six provinces. We find that only 47% of farmers （mainly farmers with large herds） adopted control measures against wild birds and rodents, while 14% adopted no measures. Farm size was the biggest driver of adoption followed by proportion of farm revenue derived from broiler production. However, southern farmers were at a far greater probability of non-adoption. We suggest that assistance in the form of education/training programs and subsidized traps or baiting controls across smaller producers could help raise of the adoption level toward more effective HPAI control.展开更多
The aim of present investigation is to study the effect of single- and co-infection with REV and ALV-J on T lymphocytes bioactivities and histopathology in broiler chickens. The bioactivities of blood and spleen T lym...The aim of present investigation is to study the effect of single- and co-infection with REV and ALV-J on T lymphocytes bioactivities and histopathology in broiler chickens. The bioactivities of blood and spleen T lymphocytes including lymphoproliferation responses, cytotoxicitic responses, and histopathology of spleen were detected in broiler chickens singly- or co-infected with REV and ALV-J at different days post inoculation and the virus expressions in spleen of infected broiler chickens were detected with immunofluorescence assay （IFA）. The results indicated that blood and spleen T lymphocytes proliferation responses and cytotoxicity in broilers infected with REV or/and ALV-J were inhibited in the whole observed period compared with controls. In the co-infected chickens they were highly inhibited than in the single-infected. The histopathology of spleen in infected chickens at 17 and 37 d post inoculation （dpi） indicated that cell interium increased, the numbers of lymphocytes decreased, and the regrowth were destroyed or decreased, especially more significantly at 17 than at 37 dpi. The different numbers of virus were detected in spleen lymphocytes in REV- infected and/or ALV-J-infected chickens. In the spleen of co-infected chicken, both REV and ALV-J were detected and the total numbers of viruses were more than in chickens singly-infected with REV or ALV-J. Thus, the co-effect of REV and ALV-J caused more immunosuppression on T lymphocytes bioactivities in broiler chickens than single-effect of ALV-J or REV, which contributed to the sever histopathology and the product of tumor cells. This study will be helpful for understanding the effect of co-infection with many viruses and control them in poultry.展开更多
基金Supported by Faculty of Veterinary Medicine,University of Urmia,Iran(Grant No.1254-31/3/91)
文摘Objective:To demonstrate seroprevalence of avian invluenza(H9N2)subtybe in broiler chickens in Northwest of Iran.Materials:A total of 310 blood samples were collected from 25 broiler flocks in slaughterhouses of West Azarbayjan,Iran.Serum samples were subjected to haemagglutination inhibition test.Results:The test showed 40.6%of positive serums.Mean antibody titer of avian influenza virus differed between geographical locations in this survey.Conclusions:High prevalence of avian influenza virus antibodies in serum of birds emphasize that avian influenza has an important role in respiratory complexes in broiler chickens in this region,and probably throughout Iran.Biosecurity measures,monitoring and surveillance programs,and to some degree vaccination are effective tools to prevent introduction of H9N2infection and its economic losses.
文摘We examined 50 Escherichia coli (E. coli) strains isolated from broiler chickens between January 2013 to March 2014 in order to evaluate the epidemiological prevalence of avian pathogenic E. coli (APEC) in Jordan by multiplex PCR and random amplification of polymorphic DNA (RAPD) tests. The multiplex polymerase chain reaction (PCR) which was used as tentative criteria of APEC targets 8 virulence associated genes;enteroaggregative toxin (astA), Type 1 fimbria adhesion (fimH), iron-repressible protein (irp2), P fimbriae (papC), aerobactin (iucD), temperature-sensitive hemagglutinin (tsh), vacuolating autotransporter toxin (vat), and colicin V plasmid operon (cva/cvi) genes. The number of detected genes could be used as a reliable index of their virulence. E. coli strains already typed as an APEC always harbor 5 to 8 genes, but non-APEC strains harbor less than 4 genes. Assuming the criteria of an APEC is possession of 5 or more virulence associated genes;we found that all 50 E. coli strains were classified as APEC strains. The RAPD analysis showed that the E. coli strains could be grouped into 35 of RAPD types by using these two different RAPD primer sets, RAPD analysis primer 4 5'AAGAGCCCGT5', and RAPD analysis primer 6 5'CCCGTCAGCA3'. The current study confirmed the endemic nature of APEC in broiler flocks in Jordan. It is essential that the biosecurity on poultry farms should be improved to prevent the introduction and dissemination of APEC and other agents. Furthermore, farmers need to be educated about the signs, lesions, and the importance of this agent.
文摘Low pathogenic Avian Influenza (AI) virus has the ability to evolve to high pathogenic viruses resulting in significant economic losses in the poultry sector. This study aims at assessing the impact of H9N2 viral passaging in broilers and its relatedness to pathogenicity and amino acid (a.a) sequences of the hemagglutinin (HA) cleavage site and neuraminidase (NA) stalk. The original H9N2 AI virus (P0) was used to challenge ten-21 days old broilers. Individual recovery of H9N2 virus from homogenates of trachea, lungs and airsacs was attempted in 9 days old chicken embryos, as a conclusion of the first passage (P1). Tracheal isolates of H9N2 were passaged for a second (P2) and a third (P3) time in broilers, followed by a similar embryonic recovery procedure. The a.a. sequence of a part of HA1 cleavage site and Neuraminidase stalk were compared among the differently passaged viruses;an assessement of the relatedness of the determined a.a. sequences to the pathogenicity in broilers, based on frequency of mortality, morbidity signs, gross and microscopic lesions at 3 days post challenge with the P1, P2, and P3-H9N2, is concluded. An increase in certain morbidity signs and specific lesions was observed in P2- and P3-H9N2 challenged broilers compared to birds challenged with P1-H9N2. A conserved R-S-S-R amino acid sequence at the HA1 cleavage site was observed in the differently passaged H9N2, associated with a variability in the NA stalk-a.a sequences. The passaging of the low pathogenic H9N2 virus in broilers leads to a trend of increase in pathogenicity, manifested in higher frequency of morbidity signs, and of specific gross and microscopic lesions of the examined organs. This passaging was associated with a conserved a.a. sequence of the hemaglutinin cleavage site and a variability in the sequence of the neuraminidase stalk. A detailed study of the potential of the detected variability in the neuraminidase stalk of H9N2 in induction of a higher pathogenicity in broilers will be the subject of future investigations.
基金supported by the Agricultural Science and Technology Innovation Program,Chinese Academy of Agricultural Sciences (ASTIP-IAED-2016)the Modern Agro-industry Technology Research System,China (CARS42-G24)
文摘Highly pathogenic avian influenza （HPAI） contamination via wild birds and rodents poses a threat to food security and safety. As chicken meat comprises an increasing proportion of diet in China, it is useful to determine whether broiler farmers are adopting wild bird and rodent controls to minimize the risk of HPAI impacts on food supply. Our study surveyed a cross sectional sample of 331 Chinese broiler farmers in six provinces. We find that only 47% of farmers （mainly farmers with large herds） adopted control measures against wild birds and rodents, while 14% adopted no measures. Farm size was the biggest driver of adoption followed by proportion of farm revenue derived from broiler production. However, southern farmers were at a far greater probability of non-adoption. We suggest that assistance in the form of education/training programs and subsidized traps or baiting controls across smaller producers could help raise of the adoption level toward more effective HPAI control.
基金supported by the Special Fund for Agroscientific Research in the Public Interest, China(200803019)the Youth Innovation Foudation of Shandong Agricultural University, China (23477)
文摘The aim of present investigation is to study the effect of single- and co-infection with REV and ALV-J on T lymphocytes bioactivities and histopathology in broiler chickens. The bioactivities of blood and spleen T lymphocytes including lymphoproliferation responses, cytotoxicitic responses, and histopathology of spleen were detected in broiler chickens singly- or co-infected with REV and ALV-J at different days post inoculation and the virus expressions in spleen of infected broiler chickens were detected with immunofluorescence assay （IFA）. The results indicated that blood and spleen T lymphocytes proliferation responses and cytotoxicity in broilers infected with REV or/and ALV-J were inhibited in the whole observed period compared with controls. In the co-infected chickens they were highly inhibited than in the single-infected. The histopathology of spleen in infected chickens at 17 and 37 d post inoculation （dpi） indicated that cell interium increased, the numbers of lymphocytes decreased, and the regrowth were destroyed or decreased, especially more significantly at 17 than at 37 dpi. The different numbers of virus were detected in spleen lymphocytes in REV- infected and/or ALV-J-infected chickens. In the spleen of co-infected chicken, both REV and ALV-J were detected and the total numbers of viruses were more than in chickens singly-infected with REV or ALV-J. Thus, the co-effect of REV and ALV-J caused more immunosuppression on T lymphocytes bioactivities in broiler chickens than single-effect of ALV-J or REV, which contributed to the sever histopathology and the product of tumor cells. This study will be helpful for understanding the effect of co-infection with many viruses and control them in poultry.
