RESUMEN

Frequent outbreaks of avian influenza H9N2 virus in Pakistan revealed that this subtype has become endemic in the poultry industry and, besides economic losses, poses a threat to public health. The present study describes the molecular characterization and pathological alterations in naturally infected broiler chickens with the current H9N2 field strain and their phylogenomic dynamics. In this study, tissue samples (trachea, lung, kidney and intestine) from 100 commercial chicken flocks were collected from July 2018 to August 2019. Samples were subjected to molecular detection, phylogeny and subsequent pathological examination. The complete length of the HA gene was successfully amplified in five samples. Nucleotide sequencing revealed positive samples placed in a clade belonging to the B2 sub-lineage of the G1 genotype and categorized as LPAIV based on the amino acid sequence of the HA gene at the cleavage site (PAKSSR/G). Genetic analysis of the haemagglutinin (HA) gene revealed nt: 80.5%-99.5%; aa: 83.8%-98.9% homology to H9N2 strains reported previously from Pakistan, neighbouring countries, and (A/Quail/Hong Kong/G1/97). Gross lesions include a slight airsacculitis, mild hemorrhages, diffuse congestion and purulent exudate in tracheal mucosa, fibrinonecrotic cast in the trachea lumen and mild pulmonary congestion. Histopathological alterations include sloughing of epithelial cells and infiltration of inflammatory cells in the trachea, mononuclear cells (MNCs) infiltration, pulmonary congestion and exudate in the lumen of parabronchi, peritubular congestion in the kidneys with degeneration of tubular epithelial cells and degenerative changes in the intestinal villi epithelial cells and goblet cell hyperplasia. Immunohistochemistry analysis confirmed the presence of AIVH9N2 antigen in the trachea, lungs, kidney and intestine. Electron microscopy revealed ultrastructural changes in the trachea, including degenerated cilia, mitochondrial swelling and enlarged endoplasmic reticulum. Based on all essential analysis, the present study revealed the distribution of the H9N2 virus of G1 genotype in Punjab, Pakistan, with mild to moderate pathogenicity.

Surtos frequentes do vírus da gripe aviária H9N2 no Paquistão revelaram que esse subtipo se tornou endêmico na avicultura e, além das perdas econômicas, representa uma ameaça à saúde pública. O presente estudo descreve a caracterização molecular e as alterações patológicas em frangos de corte naturalmente infectados com a atual cepa H9N2 e sua dinâmica filogenômica. Neste estudo, amostras de tecidos (traqueia, pulmões, rim e intestino) de 100 lotes comerciais de frangos foram coletadas de julho de 2018 a agosto de 2019. As amostras foram submetidas à detecção molecular, filogenia e posterior exame patológico. O comprimento completo do gene HA foi amplificado com sucesso em cinco amostras. O sequenciamento de nucleotídeos revelou amostras positivas colocadas em um clado pertencente à sublinhagem B2 do genótipo G1 e categorizado como LPAIV com base na sequência de aminoácidos do gene da hemaglutinina (HA) no local de clivagem (PAKSSR/G). A análise genética do gene da HA revelou: nt = 80,5%-99,5%; aa = 83,8%-98,9% de homologia com cepas de H9N2 relatadas anteriormente no Paquistão e em países vizinhos (A/Quail/Hong Kong/G1/97). As lesões macroscópicas incluíram aerossaculite leve, hemorragias leves, congestão difusa e exsudato purulento na mucosa traqueal, cilindro fibrinonecrótico no lúmen da traqueia e congestão pulmonar leve. As alterações histopatológicas incluíram descamação de células epiteliais, infiltração de células inflamatórias na traqueia, infiltração de células mononucleares (MNCs), congestão pulmonar e exsudato no lúmen dos parabrônquios, congestão peritubular nos rins com degeneração das células epiteliais tubulares, alterações degenerativas nas células epiteliais das vilosidades intestinais e hiperplasia de células caliciformes. A análise imunoistoquímica confirmou a presença do antígeno AIVH9N2 na traqueia, nos pulmões, no rim e no intestino. A microscopia eletrônica revelou alterações ultraestruturais na traqueia, incluindo cílios degenerados, inchaço mitocondrial e retículo endoplasmático aumentado. Com base em todas as análises, o presente estudo revelou a distribuição do vírus H9N2 do genótipo G1 em Punjab, Paquistão, com patogenicidade de leve a moderada.

Asunto(s)

RESUMEN

Frequent outbreaks of avian influenza H9N2 virus in Pakistan revealed that this subtype has become endemic in the poultry industry and, besides economic losses, poses a threat to public health. The present study describes the molecular characterization and pathological alterations in naturally infected broiler chickens with the current H9N2 field strain and their phylogenomic dynamics. In this study, tissue samples (trachea, lung, kidney and intestine) from 100 commercial chicken flocks were collected from July 2018 to August 2019. Samples were subjected to molecular detection, phylogeny and subsequent pathological examination. The complete length of the HA gene was successfully amplified in five samples. Nucleotide sequencing revealed positive samples placed in a clade belonging to the B2 sub-lineage of the G1 genotype and categorized as LPAIV based on the amino acid sequence of the HA gene at the cleavage site (PAKSSR/G). Genetic analysis of the haemagglutinin (HA) gene revealed nt: 80.5%-99.5%; aa: 83.8%-98.9% homology to H9N2 strains reported previously from Pakistan, neighbouring countries, and (A/Quail/Hong Kong/G1/97). Gross lesions include a slight airsacculitis, mild hemorrhages, diffuse congestion and purulent exudate in tracheal mucosa, fibrinonecrotic cast in the trachea lumen and mild pulmonary congestion. Histopathological alterations include sloughing of epithelial cells and infiltration of inflammatory cells in the trachea, mononuclear cells (MNCs) infiltration, pulmonary congestion and exudate in the lumen of parabronchi, peritubular congestion in the kidneys with degeneration of tubular epithelial cells and degenerative changes in the intestinal villi epithelial cells and goblet cell hyperplasia. Immunohistochemistry analysis confirmed the presence of AIVH9N2 antigen in the trachea, lungs, kidney and intestine. Electron microscopy revealed ultrastructural changes in the trachea, including degenerated cilia, mitochondrial swelling and enlarged endoplasmic reticulum. Based on all essential analysis, the present study revealed the distribution of the H9N2 virus of G1 genotype in Punjab, Pakistan, with mild to moderate pathogenicity.

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RESUMEN

Background: Ethanol and fructose are two important industrial products that enjoy many uses. In this contribution, their production via selective fermentation of date extract using Saccharomyces cerevisiae was studied. Scaling up the process for possible commercialization was investigated in three fermentors with working volume ratio of 1:40:400. Results: Higher ethanol concentration was obtained in the larger fermentor due to conversion of fructose. Fructose yields in the 0.5-L, 7.5-L and 80-L fermentors were 99, 92 and 90%, respectively. Good fitting was obtained with the modified Monod kinetics; however, a better fit of cell mass was obtained with the modified Ghose­Tyagi model which accounts for ethanol inhibition. Conclusions: The modified Gompertz model was expanded to facilitate prediction of products' formation and fructose fractions in all three fermentors. Such expansion will be beneficial in industrial applications.

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