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@#Avian infectious bronchitis (IB), a Gammacoronavirus, is a highly contagious upper respiratory disease, affecting chickens of all ages with a significant economic threat to the poultry industry. In February 2020, a specimen of imported chicken meat product was received and requested for coronavirus testing. The result was positive for the avian coronavirus, the IB virus (IBV) by molecular detection in the pre-screening test. Thus, this study aimed to isolate and characterize the IBV from the specimen. Virus isolation via egg inoculation was attempted and IBV was successfully isolated. The S1 subunit of the spike (S) gene of the IBV was amplified, sequenced, and the Basic Local Alignment Search Tool (BLAST) analysis showed that the IBV has 99% and 98% nucleotide similarity with the Malaysian and China IBVs, respectively. The phylogenetic analysis indicated that the virus belongs to the GI-19 lineage (also known as the QX strain) and is grouped with other IBVs from Malaysia and China. The GI-19 lineage is one of the primary IB strains that circulate in Malaysia. The recovery of the virus may be due to the persistence characteristic of the virus on meat; and the cold chain practices in the imported food product prolong the survival of this coronavirus. Though IBV is not identified as a hazard in chicken meat or meat products, raw food should be cooked thoroughly before being consumed. With the increase in international trade in poultry and poultry products, disease screening at the entry point and import risk analysis is crucial to ensure food safety and prevent the introduction of new viruses into Malaysia.
RESUMEN
Aims@#The aim of the study is to develop the optimised parameters of electrochemical DNA biosensors for the specific detection of the Infectious Bronchitis Virus (IBV) in chickens. The goal is to further create a highly sensitive and specific biosensor that can be used for on-site monitoring of IBV on poultry farms. @*Methodology and results@#In this study, an electrochemical DNA biosensor was developed for detecting a specific sequence in the IBV genome. The process involved attaching a NH2-ssDNA probe to a gold electrode, followed by hybridization with the target DNA. Various parameters like buffer, pH, scan rate, incubation time, redox indicators and temperature were optimised using cyclic voltammetry. The probe DNA was designed to enhance hybridization efficiency, which was assessed by measuring current signals. The biosensor, under optimal conditions, demonstrated high sensitivity and specificity when tested with different sequences, including complementary, non-complementary and mismatched ones. Cross-reactivity studies against non-IBV viruses showed distinguishable current signals. These findings have implications for developing a portable on-site IBV monitoring device for use on farms. @*Conclusion, significance and impact of study @#The optimised parameters and specificity of the electrochemical DNA biosensor suggest its potential for the development of a portable device for on-site monitoring of IBV on poultry farms. This device could prove to be a valuable tool for the early detection of IBV, helping to prevent further spread of the disease. However, it's essential to conduct further research to ensure the practicality and accuracy of the biosensor in real-world farm settings.
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Resumen La enfermedad por el nuevo coronavirus 2019 (COVID-19) es causada por el virus denominado SARS-CoV-2, no obstante, en los pollos de corral los coronavirus causan Bronquitis Infecciosa Aviar. En la actualidad, se ha logrado analizar la secuencia genómica del virus SARS-CoV-2, el cual indica que éste emergió de un reservorio animal, incluso se ha considerado que un virus aislado de un murciélago, idéntico a SARS-CoV, sea el progenitor del nuevo coronavirus. En otros estudios, se ha evidenciado que la glicoproteína de la espícula viral tiene un alto grado de emparentamiento entre virus que infectan mamíferos y aves, que es la que permite el contacto con el huésped. Mientras que en el caso del IBV, al inhalarse, el virus se ligará a los receptores de glucoproteína que contienen ácido siálico en las células epiteliales ciliadas del tejido respiratorio, entonces la replicación viral dará como resultado la pérdida de la función ciliar, acopiamiento de moco, necrosis y descamación, provocando dificultad para respirar y asfixia. El IBV afecta tráquea, riñones y tracto reproductivo de muchas aves. En el caso de las gallinas, el IBV virémico causa lesiones en el magnum y en el útero. Esta revisión dilucida algunos puntos clave en las diferencias en el nuevo coronavirus y el virus de la bronquitis infecciosa. Es muy poco probable que SARS-CoV-2 infecte o cause enfermedades en las aves de corral.
Abstract The new coronavirus 2019 disease (COVID-19) is caused by the virus called SARS-CoV-2, however, in free-range chicken's coronaviruses cause Avian Infectious Bronchitis. Currently, it has been possible to analyze the genomic sequence of the SARS-CoV-2 virus, which indicates that it emerged from an animal reservoir, it has even been considered that a virus isolated from a bat, identical to SARS-CoV, is the parent of the new coronavirus. In other studies, it has been shown that the glycoprotein of the viral spicule has a high degree of relationship between viruses that infect mammals and birds, which is the one that allows contact with the host. Whereas in the case of IBV, when inhaled, the virus will bind to sialic acid-containing glycoprotein receptors in hair epithelial cells of respiratory tissue, then viral replication will result in loss of ciliary function, mucus clearance, necrosis, and peeling, causing shortness of breath and suffocation. IBV affects the trachea, kidneys, and reproductive tract of many birds. In chickens, viremic IBV causes lesions in the magnum and the uterus. This review elucidates some key points in the differences between the novel coronavirus and the infectious bronchitis virus. SARS-CoV-2 is highly unlikely to infect or cause disease in poultry.
Resumo A nova doença coronavírus 2019 (COVID-19) é causada pelo vírus denominado SARS-CoV-2, no entanto, em galinhas caipiras, os coronavírus causam bronquite infecciosa aviária. Atualmente, foi possível analisar a sequência genômica do vírus SARS-CoV-2, o que indica que ele emergiu de um reservatório animal, inclusive se considerou que um vírus isolado de um morcego, idêntico ao SARS-CoV, é o progenitor do novo coronavírus. Em outros estudos, foi demonstrado que a glicoproteína da espícula viral possui alto grau de parentesco entre os vírus que infectam mamíferos e aves, o que permite o contato com o hospedeiro. Enquanto no caso do IBV, quando inalado, o vírus se liga aos receptores de glicoproteína contendo ácido siálico nas células epiteliais ciliadas do tecido respiratório, a replicação viral resultará em perda da função ciliar, acúmulo de muco , necrose e descamação, causando falta de ar e sufocação. O IBV afeta a traqueia, os rins e o trato reprodutivo de muitas aves. No caso das galinhas, o IBV virêmico causa lesões no magno e no útero. Esta revisão elucida alguns pontos-chave nas diferenças entre o novo coronavírus e o vírus da bronquite infecciosa. É altamente improvável que o SARS-CoV-2 infecte ou cause doenças em aves.
RESUMEN
Twelve Brazilian isolates and one reference vaccine strain of avian infectious bronchitis virus (IBV) were propagated in embryonating chicken eggs. The entire S1 glycoprotein gene of these viruses was analysed by reverse-transcriptase-polymerase chain reaction and restriction fragment length polymorphism (RT-PCR-RFLP), using the restriction enzymes HaeIII, XcmI and BstyI. The RFLP patterns led to the classification of these isolates into five distinct genotypes: A, B, C, D and Massachusetts. Five of twelve isolates were grouped in Massachusetts genotype and the remaining seven viruses were classified into four distinct genotypes: A (2), B (2), C (2) or D (1). Such genotyping classification agreed with previous immunological analysis for most of these viruses, highlighting the occurrence of a relevant variability among the IBV strains that are circulating in Brazilian commercial poultry flocks.
Doze isolados de campo do Brasil e uma estirpe de referência vacinal do vírus da bronquite infecciosa das aves (VBI) foram propagadas em ovos embrionados SPF. O gene S1 dessas amostras foi analisado por RT-PCR seguido de RFLP, empregando-se as enzimas de restrição HaeIII, XcmI e BstyI. Observou-se a existência de cinco genotipos diferentes: M (Massachusetts), A , B, C e D. Cinco dos doze isolados de campo do VBI foram classificados no genótipo Massachusetts e os sete vírus restantes foram classificados em quatro genotipos diferentes; A (2), B (2), C (2) ou D (1). Os resultados desta genotipagem concordam com os dados obtidos na análise imunológica previamente realizada para a maior parte destes vírus, destacando a ocorrência de uma variabilidade marcante entre os isolados do VBI que estão circulando nas granjas avícolas comerciais do Brasil.