RECENT UPDATES ON MOLECULAR DETECTION OF H9N2 AS LOW PATHOGENIC STRAIN OF AVIAN INFLUENZA VIRUS FROM POULTRY FARMS OF LAHORE, PAKISTAN

2021 ◽  
Vol 5 ◽  
pp. 15-20
Author(s):  
Muhammad Mubeen Sajjad ◽  
Majeeda Rasheed

H9N2 avian influenza outbreaks have caused great economic losses to the poultry industry in recent decades due to a decrease of egg production, high morbidity, and mortality. Due to different antigenic variants, Influenza virus has become problematical because it has the ability to cross the species barrier. As it is highly pathogenic so its diagnosis and vaccines are of high importance. Hemagglutination inhibition (HI) test is mostly used for subtyping and detection of antibody titer against the virus. Furthermore, its continuous mutations in the HA gene transforms AIV subtype H9N2 (a low pathogenic subtype) into high pathogenic virus subtypes like H5N2 and H7N7 that may have pandemic potential. Thus, it is necessary to identify various antigenic variants of Influenza virus, so it is direly needed to study the HA gene, its attachment to host receptors, the release of genetic material and pathogenicity. In the present study, virus samples from poultry were isolated. Both serological and molecular confirmation was done for 100 samples collected from the different area. They were properly labeled and prepared for the process of egg inoculation in embryonated eggs. The virus was grown in amnioallantoic membrane of embryonated eggs and harvested fluid is then proceeded for confirmatory testing. Hemagglutination and Hemagglutination inhibition testing was done. RNA was extracted by the kit method and cDNA was synthesized. Reverse transcriptase (RTPCR) was performed using specific primer sets and then the PCR product was run on agarose gel. The bands obtained were sent for sequencing.

Vaccine ◽  
2013 ◽  
Vol 31 (50) ◽  
pp. 5953-5959 ◽  
Author(s):  
Xiaomei Liu ◽  
Shuangshi Wei ◽  
Yan Liu ◽  
Peifen Fu ◽  
Mingchun Gao ◽  
...  

Viruses ◽  
2021 ◽  
Vol 13 (10) ◽  
pp. 2057
Author(s):  
Eun-Jee Na ◽  
Young-Sik Kim ◽  
Yoon-Ji Kim ◽  
Jun-Soo Park ◽  
Jae-Ku Oem

H7 low pathogenic avian influenza viruses (LPAIVs) can mutate into highly pathogenic avian influenza viruses (HPAIVs). In addition to avian species, H7 avian influenza viruses (AIVs) also infect humans. In this study, two AIVs, H7N9 (20X-20) and H7N7 (34X-2), isolated from the feces of wild birds in South Korea in 2021, were genetically analyzed. The HA cleavage site of the two H7 Korean viruses was confirmed to be ELPKGR/GLF, indicating they are LPAIVs. There were no amino acid substitutions at the receptor-binding site of the HA gene of two H7 Korean viruses compared to that of A/Anhui/1/2013 (H7N9), which prefer human receptors. In the phylogenetic tree analysis, the HA gene of the two H7 Korean viruses shared the highest nucleotide similarity with the Korean H7 subtype AIVs. In addition, the HA gene of the two H7 Korean viruses showed high nucleotide similarity to that of the A/Jiangsu/1/2018(H7N4) virus, which is a human influenza virus originating from avian influenza virus. Most internal genes (PB2, PB1, PA, NP, NA, M, and NS) of the two H7 Korean viruses belonged to the Eurasian lineage, except for the M gene of 34X-2. This result suggests that active reassortment occurred among AIVs. In pathogenicity studies of mice, the two H7 Korean viruses replicated in the lungs of mice. In addition, the body weight of mice infected with 34X-2 decreased 7 days post-infection (dpi) and inflammation was observed in the peribronchiolar and perivascular regions of the lungs of mice. These results suggest that mammals can be infected with the two H7 Korean AIVs. Our data showed that even low pathogenic H7 AIVs may infect mammals, including humans, as confirmed by the A/Jiangsu/1/2018(H7N4) virus. Therefore, continuous monitoring and pathogenicity assessment of AIVs, even of LPAIVs, are required.


2020 ◽  
Vol 13 (11) ◽  
pp. 2493-2501
Author(s):  
Jossie Intan Cahyani ◽  
Sitarina Widyarini ◽  
Michael Haryadi Wibowo

Background and Aim: Newcastle disease (ND) and avian influenza (AI) are two devastating diseases of poultry, which cause great economic losses to the poultry industry and disrupt food security in our country. The use of ND-AI inactive bivalent vaccine is very effective and economical to prevent and control ND and AI disease. Bivalent ND LaSota-AI H9N2 vaccine is not yet available in Indonesia. The inactivated vaccines used in poultry industry often require oil adjuvant to elicit a sufficient immune response. This study aimed to develop the bivalent inactive vaccines containing ND LaSota and AI H9N2 Sidrap isolate which are local isolates as poultry vaccine candidates, and formulated with two different commercial adjuvants, then compared. Materials and Methods: Two vaccines bivalent were prepared by emulsifying inactivated Newcastle disease virus (LaSota strain) and AI H9N2 Sidrap isolate viruses with Marcol white mineral oil and Montanide ISA70 adjuvants. Both of bivalent vaccines were tested for safety (physical and histopathological at the injection site) and efficacy in specific-pathogen-free chickens. Parameters used for the evaluation of the efficacy were immunogenicity by hemagglutination inhibition and protection percentage. Results: Both bivalent vaccines are safe to use. Post-vaccination (PV) immune response was observed using a hemagglutination inhibition test at 2, 3, 4, 5, 6, 7, and 8 weeks of PV. The bivalent vaccine B gives a better immune response to ND at 2, 3, and 4 weeks of PV (p<0.05) compared to the bivalent vaccine A, but in 5, 6, 7, and 8 weeks, the PV does not show differences in the immune response. The immune response to AI H9N2 showed differences at weeks 2 and 3 PV (p<0.05) with the bivalent vaccine B indicated higher immunity. A single immunization with both bivalent vaccines induces 100% protection in chickens that have been vaccinated against the deadly challenge with the virulent ND virus. Conclusion: Both of bivalent vaccines are safe to use and provide good efficacy against virulent ND viruses, but bivalent vaccine B (with Montanide ISA70 adjuvant) shows better immune response than bivalent vaccine A (Marcol white mineral oil adjuvant).


2020 ◽  
Vol 7 (2) ◽  
pp. 73 ◽  
Author(s):  
Mohammad M. Hassan ◽  
Mohamed E. El Zowalaty ◽  
Ariful Islam ◽  
Shahneaz A. Khan ◽  
Md. K. Rahman ◽  
...  

Highly pathogenic avian influenza H5 viruses have pandemic potential, cause significant economic losses and are of veterinary and public health concerns. This study aimed to investigate the distribution and diversity of hemagglutinin (HA) subtypes of avian influenza virus (AIV) in poultry and wild birds in Bangladesh. We conducted an avian influenza sero-surveillance in wild and domestic birds in wetlands of Chattogram and Sylhet in the winter seasons 2012–2014. We tested serum samples using a competitive enzyme-linked immunosorbent assay (c-ELISA), and randomly selected positive serum samples (170 of 942) were tested using hemagglutination inhibition (HI) to detect antibodies against the 16 different HA sero-subtypes. All AIV sero–subtypes except H7, H11, H14 and H15 were identified in the present study, with H5 and H9 dominating over other subtypes, regardless of the bird species. The diversity of HA sero-subtypes within groups ranged from 3 (in household chickens) to 10 (in migratory birds). The prevalence of the H5 sero-subtype was 76.3% (29/38) in nomadic ducks, 71.4% (5/7) in household chicken, 66.7% (24/36) in resident wild birds, 65.9% (27/41) in migratory birds and 61.7% (29/47) in household ducks. Moreover, the H9 sero-subtype was common in migratory birds (56%; 23/41), followed by 38.3% (18/47) in household ducks, 36.8% (14/38) in nomadic ducks, 30.6% (11/66) in resident wild birds and 28.5% (2/7) in household chickens. H1, H4 and H6 sero-subtypes were the most common sero-subtypes (80%; 8/10, 70%; 7/10 and 70%; 7/10, respectively) in migratory birds in 2012, H9 in resident wild birds (83.3%; 5/6) and H2 in nomadic ducks (73.9%; 17/23) in 2013, and the H5 sero-subtype in all types of birds (50% to 100%) in 2014. The present study demonstrates that a high diversity of HA subtypes circulated in diverse bird species in Bangladesh, and this broad range of AIV hosts may increase the probability of AIVs’ reassortment and may enhance the emergence of novel AIV strains. A continued surveillance for AIV at targeted domestic–wild bird interfaces is recommended to understand the ecology and evolution of AIVs.


Viruses ◽  
2019 ◽  
Vol 11 (1) ◽  
pp. 40 ◽  
Author(s):  
Mengchan Hao ◽  
Shaojie Han ◽  
Dan Meng ◽  
Rong Li ◽  
Jing Lin ◽  
...  

The polymerase acidic (PA) protein is the third subunit of the influenza A virus polymerase. In recent years, studies have shown that PA plays an important role in overcoming the host species barrier and host adaptation of the avian influenza virus (AIV). The objective of this study was to elucidate the role of the PA subunit on the replication and airborne transmission of the H9N2 subtype AIV. By reverse genetics, a reassortant rSD01-PA was derived from the H9N2 subtype AIV A/Chicken/Shandong/01/2008 (SD01) by introducing the PA gene from the pandemic influenza A H1N1 virus A/swine/Shandong/07/2011 (SD07). Specific pathogen-free (SPF) chickens and guinea pigs were selected as the animal models for replication and aerosol transmission studies. Results show that rSD01-PA lost the ability of airborne transmission among SPF chickens because of the single substitution of the PA gene. However, rSD01-PA could infect guinea pigs through direct contact, while the parental strain SD01 could not, even though the infection of rSD01-PA could not be achieved through aerosol. In summary, our results indicate that the protein encoded by the PA gene plays a key role in replication and airborne transmission of the H9N2 subtype AIV.


2013 ◽  
Vol 8 (6) ◽  
pp. 520-526 ◽  
Author(s):  
Dawid Nidzworski ◽  
Krzysztof Smietanka ◽  
Zenon Minta ◽  
Bogusław Szewczyk

AbstractNewcastle disease Virus (NDV), a member of the Paramyxoviridae family, and Influenza virus, from the Orthomyxoviridae family, are two main avian pathogens that cause serious economic problems in poultry farming. NDV strains are classified into three major pathotypes: velogenic, mesogenic, and lentogenic. Avian influenza viruses (AIV) are also divided into: low pathogenic (LPAI) and highly pathogenic (HPAI) strains. Both viruses are enveloped, single stranded, negative-sense RNA viruses which give similar symptoms ranging from sub-clinical infections to severe disease, including loss in egg production, acute respiratory syndrome, and high mortality, depending on their level of pathogenicity. This similarity hinders diagnosis when based solely on clinical and post mortem examination. Most of the currently available molecular detection methods are also pathogenspecific, so that more than one RT-PCR is then required to confirm or exclude the presence of both pathogens. To overcome this disadvantage, we have applied a One Step Duplex RT-PCR method to distinguish between those two pathogens. The main objective of the project was to develop a universal, fast, and inexpensive method which could be used in any veterinary laboratory.


2019 ◽  
Vol 37 (1) ◽  
pp. 1
Author(s):  
Rina Isnawati ◽  
Hastari Wuryastuti ◽  
R Wasito

Decreasing egg production is an initial symptom of various diseases that infect commercial layer chickens. Diagnosis of diseases causing the decrease in egg production without high mortality rate is often thought to be caused by other poultry diseases because of the many similarities in manifestation between one disease and another. Avian influenza is a zoonotic infectious disease in poultry that can lead to high economic losses. This study aims to determine the contribution of avian influenza virus (AIV) infection to commercial laying hens showing symptoms of decreased production. The samples were oropharyngeal swabs of commercial laying hens which had symptoms of decreased production at productive age. Laboratory tests were carried out by histopathological examination, detection and identification of AIV with real time reverse transcriptase polymerase chain reaction (qRT-PCR) and isolation with the viral culture technique on fertile chicken eggs. The results showed that there was type A AIV infection based on the qRT-PCR (matrix) test, but the subtypes were not identified (H5, H7, H9). The results of the isolation of the virus in the fertile chicken eggs showed embryonic death in which all embryonic organs show hemorrhages. Allantoic fluid does not agglutinate chicken red blood cells. Histopathological features of the pathognomonic lesions in lungs infected with AIV were severe congestion and hemorrhages. Based on the results of the study, it was concluded that there was a contribution of type A AIV infection. Early diagnosis of AIV could determine more appropriate actions, including control, prevention and eradication.


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