RESUMO
Concrete structures are susceptible to cracking, which can compromise their integrity and durability. Repairing them with ordinary Portland cement (OPC) paste causes shrinkage cracks to appear in the repaired surface. Alkali-activated binders offer a promising solution for repairing such cracks. This study aims to develop an alkali-activated paste (AAP) and investigate its effectiveness in repairing concrete cracks. AAPs, featuring varying percentages (0.5%, 0.75%, 1%, 1.25%, 1.5%, and 1.75%) of polyethylene (PE) fibers, are found to exhibit characteristics such as strain hardening, multiple plane cracking in tension and flexure tests, and stress-strain softening in compression tests. AAP without PE fibers experienced catastrophic failure in tension and flexure, preventing the determination of its stress-strain relationship. Notably, AAPs with 1.25% PE fibers demonstrated the highest tensile and flexural strength, exceeding that of 0.5% PE fiber reinforced AAP by 100% in tension and 70% in flexure. While 1% PE fibers resulted in the highest compressive strength, surpassing AAP without fibers by 17%. To evaluate the repair performance of AAP, OPC cubes were cast with pre-formed cracks. These cracks were induced by placing steel plates during casting and were designed to be full and half-length with widths of 1.5 mm and 3 mm. AAP both with and without PE fibers led to a substantial improvement in compressive strength, reducing the initial strength loss of 30%-50% before repair to a diminished range of 2%-20% post-repair. The impact of PE fiber content on the compressive strength of repaired OPC cube is marginal, providing more flexibility in using AAP with any fiber percentage while still achieving effective concrete crack repair. Considering economic and environmental factors, along with observed mechanical enhancements, AAPs show promising potential for widespread use in concrete repair and related applications, contributing valuable insights to the field of sustainable construction materials.
Assuntos
Álcalis , Materiais de Construção , Teste de Materiais , Polietileno , Polietileno/química , Álcalis/química , Força Compressiva , Resistência à Tração , Estresse MecânicoRESUMO
Benign recurrent intrahepatic cholestasis is an autosomal recessive disorder presenting with intermittent episodes of cholestatic jaundice. The initial episode of benign recurrent intrahepatic cholestasis tends to occur within the first two decades of a patient's life. Episodes can occur unprompted but can often be precipitated by infections or pregnancy. We report an interesting case of a 13-year-old girl presented with recurrent intrahepatic cholestasis. The patient has a unique homozygous USP53 genetic mutation, the first patient to present with this mutation within the South Asian region. The patient was initially misdiagnosed as a case of autoimmune hepatitis, and when presenting to our set-up was diagnosed as a case of benign recurrent intrahepatic cholestasis. The patient has since been managed on medication and remains regular in follow-up, responding well to treatment.
RESUMO
IMPORTANCE: Although the role of bovine coronavirus (BCoV) in calf diarrhea and respiratory disorders is well documented, its contribution to neurological diseases is unclear. OBJECTIVE: This study conducted virological investigations of calves showing diarrhea and respiratory and neurological signs. METHODS: An outbreak of diarrhea, respiratory, and neurological disorders occurred among the 12 calves in July 2022 in Istanbul, Türkiye. Two of these calves exhibited neurological signs and died a few days after the appearance of symptoms. One of these calves was necropsied and analyzed using molecular and histopathological tests. RESULTS: BCoV RNA was detected in the brain, lung, spleen, liver, and intestine of the calf that had neurological signs by real-time reverse transcription polymerase chain reaction. Immunostaining was also observed in the intestine and brain. A 622 bp S1 gene product was noted on gel electrophoresis only in the brain. Phylogenetic analysis indicated that the BCoV detected in this study had a high proximity to the BCoV strain GIb with 99.19% nucleotide sequence homology to the strains detected in Poland, Israel, Türkiye, and France. No distinct genetic lineages were observed when the brain isolate was compared with the respiratory and enteric strains reported to GenBank. In addition, the highest identity (98,72%) was obtained with the HECV 4408 and L07748 strains of human coronaviruses. CONCLUSIONS AND RELEVANCE: The strain detected in a calf brain belongs to the GIb-European lineage and shares high sequence homology with BCoV strains detected in Europe and Israel. In addition, the similarity between the human coronaviruses (4408 and L07748) raises questions about the zoonotic potential of the strains detected in this study.
Assuntos
Encéfalo , Doenças dos Bovinos , Infecções por Coronavirus , Coronavirus Bovino , Filogenia , Animais , Bovinos , Coronavirus Bovino/genética , Coronavirus Bovino/isolamento & purificação , Infecções por Coronavirus/veterinária , Infecções por Coronavirus/virologia , Infecções por Coronavirus/patologia , Doenças dos Bovinos/virologia , Doenças dos Bovinos/patologia , Encéfalo/virologia , Encéfalo/patologia , Turquia/epidemiologia , Surtos de Doenças/veterinária , Pneumonia Viral/veterinária , Pneumonia Viral/virologia , Pneumonia Viral/patologia , Doenças do Sistema Nervoso/veterinária , Doenças do Sistema Nervoso/virologia , Doenças do Sistema Nervoso/patologiaRESUMO
BACKGROUND: Fowl adenovirus-4 is a causative agent of hydropericardium hepatitis syndrome (HHS) in chickens and has been frequently reported from many countries. Fowl adenoviruses cause severe disease and mortality in broiler and layer breeders in Azerbaijan. Therefore, in this study, pathological lesions and the dissemination of fowl adenovirus-4 into the visceral organs of infected birds were investigated as well as molecular characterisation of detected strains. For this, liver, heart and spleen from 20 necropsied chickens originated from a broiler breeder flock and a layer breeder flock were embeded on the FTA cards and the samples were analysed for adenovirus-DNA by PCR and sequencing. RESULTS: The findings of necropsy in both broiler and layer breeder chickens were similar, and the liver was severely effected showing hepatitis, and the heart with hydropericardium lesions. The kidneys were swollen with haemorrhages and small white foci on the surface of the spleens were noted. Intestinal congestion and ecchymotic hemorrhages were also observed in some birds. Fowl adenovirus-4-DNA was detected by PCR in all collected organs of 20 birds. The sequence analysis revealed that fowl adenovirus-4 present in Azerbaijan and close similarity of the hexon genes of the adenoviruses existing in the Middle East, North America, far east and Indian subcontinent were determined by phylogenetic analysis. However, sequence diversity was detected from the adenovirus strains circulating in Europe, North and South America. CONCLUSIONS: This study indicates the impact of fowl adenovirus-4 on the poultry health and production, and improved disease control and prevention strategies are necessary to reduce the HHS disease in chickens in Azerbaijan.
Assuntos
Infecções por Adenoviridae , Galinhas , Filogenia , Doenças das Aves Domésticas , Animais , Doenças das Aves Domésticas/virologia , Doenças das Aves Domésticas/epidemiologia , Doenças das Aves Domésticas/patologia , Infecções por Adenoviridae/veterinária , Infecções por Adenoviridae/virologia , Infecções por Adenoviridae/epidemiologia , Azerbaijão/epidemiologia , Aviadenovirus/genética , Aviadenovirus/isolamento & purificação , Aviadenovirus/classificação , Hepatite Viral Animal/virologia , Hepatite Viral Animal/patologia , Hepatite Viral Animal/epidemiologia , DNA Viral/genética , Fígado/patologia , Fígado/virologia , Baço/patologia , Baço/virologiaRESUMO
The complement system is an innate immune mechanism against microbial infections. It involves a cascade of effector molecules that is activated via classical, lectin and alternative pathways. Consequently, many pathogens bind to or incorporate in their structures host negative regulators of the complement pathways as an evasion mechanism. Factor H (FH) is a negative regulator of the complement alternative pathway that protects "self" cells of the host from non-specific complement attack. FH has been shown to bind viruses including human influenza A viruses (IAVs). In addition to its involvement in the regulation of complement activation, FH has also been shown to perform a range of functions on its own including its direct interaction with pathogens. Here, we show that human FH can bind directly to IAVs of both human and avian origin, and the interaction is mediated via the IAV surface glycoprotein haemagglutinin (HA). HA bound to common pathogen binding footprints on the FH structure, complement control protein modules, CCP 5-7 and CCP 15-20. The FH binding to H1 and H3 showed that the interaction overlapped with the receptor binding site of both HAs, but the footprint was more extensive for the H3 HA than the H1 HA. The HA - FH interaction impeded the initial entry of H1N1 and H3N2 IAV strains but its impact on viral multicycle replication in human lung cells was strain-specific. The H3N2 virus binding to cells was significantly inhibited by preincubation with FH, whereas there was no alteration in replicative rate and progeny virus release for human H1N1, or avian H9N2 and H5N3 IAV strains. We have mapped the interaction between FH and IAV, the in vivo significance of which for the virus or host is yet to be elucidated.
Assuntos
Fator H do Complemento , Glicoproteínas de Hemaglutininação de Vírus da Influenza , Vírus da Influenza A , Influenza Humana , Ligação Proteica , Humanos , Fator H do Complemento/metabolismo , Fator H do Complemento/imunologia , Animais , Influenza Humana/imunologia , Influenza Humana/virologia , Influenza Humana/metabolismo , Vírus da Influenza A/imunologia , Vírus da Influenza A/fisiologia , Glicoproteínas de Hemaglutininação de Vírus da Influenza/metabolismo , Glicoproteínas de Hemaglutininação de Vírus da Influenza/imunologia , Sítios de Ligação , Influenza Aviária/virologia , Influenza Aviária/imunologia , Influenza Aviária/metabolismo , Aves/virologia , Interações Hospedeiro-Patógeno/imunologia , Vírus da Influenza A Subtipo H3N2/imunologia , Vírus da Influenza A Subtipo H9N2/imunologiaRESUMO
Avian influenza A virus (AIV) is a significant cause of mortality in poultry, causing substantial economic loss, particularly in developing countries, and has zoonotic potential. For example, highly pathogenic avian influenza (HPAI) viruses of the H5 subtype have been circulating in Egypt for around two decades. In the last decade, H5N1 viruses of clade 2.2.1 have been succeeded by the antigenically distinct H5N8 clade 2.3.4.4b viruses. Furthermore, H9N2 viruses co-circulate with the H5N8 viruses in Egyptian poultry. It is widely recognised that effective vaccination against IAV requires a close antigenic match between the vaccine and viruses circulating in the field. Therefore, approaches to develop cost-effective vaccines that can be rapidly adapted to local virus strains are required for developing countries such as Egypt. In this project, the haemagglutinin (HA) proteins of Egyptian H5 and H9 viruses were expressed by transient transfection of plants (Nicotiana benthamiana). The formation of virus-like particles (VLPs) was confirmed by transmission electron microscopy. Mice were immunised with four doses of either H5 or H9 VLPs with adjuvant. Antibody and cellular immune responses were measured against the corresponding recombinant protein using ELISA and enzyme-linked immunosorbent assay (ELISpot), respectively. Chickens were immunised with one dose of H5 VLPs, eliciting HA-specific antibodies measured by ELISA and a pseudotyped virus neutralisation test using a heterologous H5 HA. In conclusion, plant-based VLP vaccines have potential for producing an effective vaccine candidate within a short time at a relatively low cost.
RESUMO
Influenza A virus (IAV) is the primary causative agent of influenza, colloquially called the flu. Each year, it infects up to a billion people, resulting in hundreds of thousands of human deaths, and causes devastating avian outbreaks with worldwide losses worth billions of dollars. Always present is the possibility that a highly pathogenic novel subtype capable of direct human-to-human transmission will spill over into humans, causing a pandemic as devastating if not more so than the 1918 influenza pandemic. While antiviral drugs for influenza do exist, they target very few aspects of IAV replication and risk becoming obsolete due to antiviral resistance. Antivirals targeting other areas of IAV replication are needed to overcome this resistance and combat the yearly epidemics, which exact a serious toll worldwide. This review aims to summarise the key steps in the IAV replication cycle, along with highlighting areas of research that need more focus.
Assuntos
Vírus da Influenza A , Influenza Humana , Humanos , Influenza Humana/epidemiologia , Antivirais/farmacologia , Replicação ViralAssuntos
Infecções por Bartonella , Bartonella , Endoftalmite , Infecções Oculares Bacterianas , Infecções por HIV , Sífilis , Humanos , Sífilis/complicações , Sífilis/diagnóstico , Sífilis/tratamento farmacológico , Infecções por Bartonella/complicações , Infecções por Bartonella/diagnóstico , Infecções Oculares Bacterianas/diagnóstico , Infecções Oculares Bacterianas/tratamento farmacológicoRESUMO
The possible emergence of drug-resistant avian flu raises concerns over the limited effectiveness of currently approved antivirals (neuraminidase inhibitors - NAIs) in the hypothetical event of a zoonotic spillover. Our study demonstrated that the recombinant avian A(H6N1) viruses showed reduced inhibition (RI) by multiple NAI drugs following the introduction of point mutations found predominantly in the neuraminidase gene (NA) of NAI-resistant human influenza strains (E119V, R292K and H274Y; N2 numbering). Moreover, A(H6N1)-H274Y showed increased replication efficiency in vitro, and a fitness advantage over wild-type (WT) when co-inoculated into embryonated hen's eggs. The results presented in our study together with the zoonotic potential of the A(H6N1) virus as evidenced by the human infection from 2013, highlight the need for enhanced monitoring of NAI resistance-associated signatures in circulating LPAI (low pathogenic avian influenza) globally.
Assuntos
Influenza Aviária , Influenza Humana , Animais , Feminino , Humanos , Oseltamivir/farmacologia , Galinhas , Neuraminidase/genética , Antivirais/farmacologia , Inibidores Enzimáticos/farmacologia , Mutação , Resistência a Medicamentos , Farmacorresistência Viral/genéticaRESUMO
The avian influenza viruses (AIV) of the H5 subtype have the ability to mutate from low pathogenic (LPAI) to highly pathogenic (HPAI), which can cause high mortality in poultry. Little is known about the pathogenic switching apart from the mutations at the haemagglutinin cleavage site, which significantly contributes to the virus virulence switching phenomenon. Therefore, this study aimed to compare the molecular markers in the haemagglutinin (HA), neuraminidase (NA), and matrix (M) genes of a locally isolated LPAI AIV strain H5N2 from Malaysia with the reference HPAI strains using bioinformatics approaches, emphasising the pathogenic properties of the viral genes. First, the H5N2 strain A/Duck/Malaysia/8443/2004 was propagated in SPF eggs. The viral presence was verified by haemagglutination assay, RT-PCR, and sequencing. Results showed successful amplifications of HA (1695 bp), NA (1410 bp), and M (1019 bp) genes. The genes were sequenced and the deduced amino acid sequences were analysed computationally using MEGA 11 and NetNGlyc software. Analysis of the HA protein showed the absence of the polybasic cleavage motif, but presence of two amino acid residues that are known to affect pathogenicity. There were also two glycosylation sites (glycosites) compared to the reference HPAI viruses, which had three or more at the HA globular head domain. No NA stalk deletion was detected but the haemadsorbing and active centres of the studied NA protein were relatively similar to the reference HPAI H5N2 isolates of duck but not chicken origins. Six NA glycosites were also identified. Finally, we observed a consistent M1 and M2 amino acid sequences between our LPAI isolate with the other HPAI H5N1 or H5N2 reference proteins. These data demonstrate distinct characteristics of the Malaysian LPAI H5N2, compared to HPAI H5N2 or H5N1 from ducks or chickens, potentially aiding the epidemiological research on genetic dynamics of circulating AIV in poultry.
Assuntos
Virus da Influenza A Subtipo H5N1 , Vírus da Influenza A Subtipo H5N2 , Vírus da Influenza A , Influenza Aviária , Animais , Patos/genética , Vírus da Influenza A Subtipo H5N2/genética , Influenza Aviária/genética , Galinhas/genética , Virus da Influenza A Subtipo H5N1/genética , Hemaglutininas/genética , Aves Domésticas/genética , Análise de SequênciaRESUMO
Introduction: Infectious Bursal Disease Virus (IBDV) causes immunosuppression in chickens. While B-cell destruction is the main cause of humoral immunosuppression, bursal T cells from IBDV-infected birds have been reported to inhibit the mitogenic response of splenocytes, indicating that some T cell subsets in the infected bursa have immunomodulatory activities. CD4+CD25+TGFß+ cells have been recently described in chickens that have immunoregulatory properties and play a role in the pathogenesis of Marek's Disease Virus. Methods: To evaluate if CD4+CD25+TGFß+ cells infiltrated the bursa of Fabricius (BF) following IBDV infection, and influenced the outcome of infection, birds were inoculated at either 2 days or 2 weeks of age with vaccine strain (228E), classic field strain (F52/70), or PBS (mock), and bursal cell populations were quantified by flow cytometry. Results: Both 228E and F52/70 led to atrophy of the BF, a significant reduction of Bu1+-B cells, and a significant increase in CD4+ and CD8α+ T cells in the BF, but only F52/70 caused suppression of immune responses to a test antigen in younger birds, and clinical signs in older birds. Virus was cleared from the BF more rapidly in younger birds than older birds. An infiltration of CD4+CD25+T cells into the BF, and elevated expression of bursal TGFß-1+ mRNA was observed at all time points following infection, irrespective of the strain or age of the birds, but CD4+TGFß+cells and CD4+CD25+TGFß+ cells only appeared in the BF at 28 dpi in younger birds. In older birds, CD4+TGFß+ cells and CD4+CD25+TGFß+ cells were present at earlier time points, from 7dpi following 228E infection, and from 14 and 28 dpi following F52/70 infection, respectively. Discussion: Our data suggest that an earlier infiltration of CD4+TGFß+ cells into the BF correlated with a delayed clearance of virus. However, the influx of CD4+TGFß+ cells and CD4+CD25+TGFß+ into the BF did not correlate with increased pathogenicity, or immunosuppression.
Assuntos
Vírus da Doença Infecciosa da Bursa , Animais , Bolsa de Fabricius , Galinhas , Terapia de Imunossupressão , Fator de Crescimento Transformador betaRESUMO
High pathogenicity avian influenza (HPAI) H5N1 is a subtype of the influenza A virus primarily found in birds. The subtype emerged in China in 1996 and has spread globally, causing significant morbidity and mortality in birds and humans. In Cambodia, a lethal case was reported in February 2023 involving an 11-year-old girl, marking the first human HPAI H5N1 infection in the country since 2014. This research examined the zoonotic potential of the human H5N1 isolate, A/Cambodia/NPH230032/2023 (KHM/23), by assessing its receptor binding, fusion pH, HA thermal stability, and antigenicity. Results showed that KHM/23 exhibits similar receptor binding and antigenicity as the early clade 2.3.2.1c HPAI H5N1 strain, and it does not bind to human-like receptors. Despite showing limited zoonotic risk, the increased thermal stability and reduced pH of fusion in KHM/23 indicate a potential threat to poultry, emphasizing the need for vigilant monitoring.
Assuntos
Virus da Influenza A Subtipo H5N1 , Vírus da Influenza A , Influenza Aviária , Influenza Humana , Animais , Feminino , Humanos , Criança , Influenza Aviária/epidemiologia , Hemaglutininas , Influenza Humana/epidemiologia , Camboja/epidemiologiaRESUMO
Since the first human case in 2013, H7N9 avian influenza viruses (AIVs) have caused more than 1500 human infections with a mortality rate of approximately 40%. Despite large-scale poultry vaccination regimes across China, the H7N9 AIVs continue to persist and evolve rapidly in poultry. Recently, several strains of H7N9 AIVs have been isolated and shown the ability to escape vaccine-induced immunity. To assess the zoonotic risk of the recent H7N9 AIV isolates, we rescued viruses with hemagglutinin (HA) and neuraminidase (NA) from these H7N9 AIVs and six internal segments from PR8 virus and characterized their receptor binding, pH of fusion, thermal stability, plaque morphology and in ovo virus replication. We also assessed the cross-reactivity of the viruses with human monoclonal antibodies (mAbs) against H7N9 HA and ferret antisera against H7N9 AIV candidate vaccines. The H7N9 AIVs from the early epidemic waves had dual sialic acid receptor binding characteristics, whereas the more recent H7N9 AIVs completely lost or retained only weak human sialic acid receptor binding. Compared with the H7N9 AIVs from the first epidemic wave, the 2020/21 viruses formed larger plaques in Madin-Darby canine kidney (MDCK) cells and replicated to higher titres in ovo, demonstrating increased acid stability but reduced thermal stability. Further analysis showed that these recent H7N9 AIVs had poor cross-reactivity with the human mAbs and ferret antisera, highlighting the need to update the vaccine candidates. To conclude, the newly emerged H7N9 AIVs showed characteristics of typical AIVs, posing reduced zoonotic risk but a heightened threat for poultry.
Assuntos
Subtipo H7N9 do Vírus da Influenza A , Influenza Aviária , Influenza Humana , Animais , Cães , Humanos , Furões , Hemaglutininas , Aves Domésticas , Medição de Risco , Soros Imunes , Glicoproteínas de Hemaglutininação de Vírus da InfluenzaRESUMO
Since 2013, H7N9 avian influenza viruses (AIVs) have caused more than 1,500 human infections and the culling of millions of poultry. Despite large-scale poultry vaccination, H7N9 AIVs continue to circulate among poultry in China and pose a threat to human health. Previously, we isolated and generated four monoclonal antibodies (mAbs) derived from humans naturally infected with H7N9 AIV. Here, we investigated the hemagglutinin (HA) epitopes of H7N9 AIV targeted by these mAbs (L3A-44, K9B-122, L4A-14, and L4B-18) using immune escape studies. Our results revealed four key antigenic epitopes at HA amino acid positions 125, 133, 149, and 217. The mutant H7N9 viruses representing escape mutations containing an alanine-to-threonine substitution at residue 125 (A125T), a glycine-to-glutamic acid substitution at residue 133 (G133E), an asparagine-to-aspartic acid substitution at residue 149 (N149D), or a leucine-to-glutamine substitution at residue 217 (L217Q) showed reduced or completely abolished cross-reactivity with the mAbs, as measured by a hemagglutination inhibition (HI) assay. We further assessed the potential risk of these mutants to humans should they emerge following mAb treatment by measuring the impact of these HA mutations on virus fitness and evasion of host adaptive immunity. Here, we showed that the L4A-14 mAb had broad neutralizing capabilities, and its escape mutant N149D had reduced viral stability and human receptor binding and could be neutralized by both postinfection and antigen-induced sera. Therefore, the L4A-14 mAb could be a therapeutic candidate for H7N9 AIV infection in humans and warrants further investigation for therapeutic applications. IMPORTANCE Avian influenza virus (AIV) H7N9 continues to circulate and evolve in birds, posing a credible threat to humans. Antiviral drugs have proven useful for the treatment of severe influenza infections in humans; however, concerns have been raised as antiviral-resistant mutants have emerged. Monoclonal antibodies (mAbs) have been studied for both prophylactic and therapeutic applications in infectious disease control and have demonstrated great potential. For example, mAb treatment has significantly reduced the risk of people developing severe disease with severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infection. In addition to the protection efficiency, we should also consider the potential risk of the escape mutants generated by mAb treatment to public health by assessing their viral fitness and potential to compromise host adaptive immunity. Considering these parameters, we assessed four human mAbs derived from humans naturally infected with H7N9 AIV and showed that the mAb L4A-14 displayed potential as a therapeutic candidate.
Assuntos
Subtipo H7N9 do Vírus da Influenza A , Influenza Humana , Animais , Humanos , Anticorpos Monoclonais/imunologia , Anticorpos Monoclonais/uso terapêutico , Anticorpos Antivirais/imunologia , Anticorpos Antivirais/uso terapêutico , Epitopos , Glicoproteínas de Hemaglutininação de Vírus da Influenza/genética , Subtipo H7N9 do Vírus da Influenza A/imunologia , Influenza Humana/imunologia , Influenza Humana/terapia , Evasão da Resposta Imune/genética , MutaçãoRESUMO
(1) Background: The aim of this study was to produce in-house ELISAs which can be used to determine SARS-CoV-2-specific antibody levels directed against the spike protein (S), the S1 subunit of S and the receptor binding domain (RBD) of S in SARS-CoV-2 vaccinated and infected humans. (2) Methods: Three in-house ELISAs were developed by using recombinant proteins of SARS-CoV-2, namely the S, S1 and RBD proteins. Specificity and sensitivity evaluations of these tests were performed using sera from SARS-CoV-2-infected (n = 70) and SARS-CoV-2-vaccinated (n = 222; CoronaVac vaccine) humans in Istanbul, Turkey. The analyses for the presence of SARS-CoV-2-specific antibodies were performed using the in-house ELISAs, a commercial ELISA (Abbott) and a commercial surrogate virus neutralization test (sVNT). We also analyzed archival human sera (n = 50) collected before the emergence of COVID-19 cases in Turkey. (3) Results: The sensitivity of the in-house S, S1 and RBD ELISAs was found to be 88.44, 90.17 and 95.38%, while the specificity was 72.27, 89.08 and 89.92%, respectively, when compared to the commercial SARS-CoV-2 antibody test kit. The area under curve (AUC) values were 0.777 for the in-house S ELISA, 0.926 for the S1 ELISA, and 0.959 for the RBD ELISA. The kappa values were 0.62, 0.79 and 0.86 for the S, S1 and RBD ELISAs, respectively. (4) Conclusions: The in-house S1 and RBD ELISAs developed in this study have acceptable performance characteristics in terms of sensitivity, specificity, AUC and kappa values. In particular, the RBD ELISA seems viable to determine SARS-CoV-2-specific antibody levels, both in infected and vaccinated people, and help mitigate SARS-CoV-2 outbreaks and spread.
RESUMO
H9N2 avian influenza viruses (AIVs) have donated internal gene segments during the emergence of zoonotic AIVs, including H7N9. We used reverse genetics to generate A/Anhui/1/13 (H7N9) and three reassortant viruses (2:6 H7N9) which contained the hemagglutinin and neuraminidase from Anhui/13 (H7N9) and the six internal gene segments from H9N2 AIVs belonging to (i) G1 subgroup 2, (ii) G1 subgroup 3, or (iii) BJ94 lineages, enzootic in different regions throughout Asia. Infection of chickens with the 2:6 H7N9 containing G1-like H9N2 internal genes conferred attenuation in vivo, with reduced shedding and transmission to contact chickens. However, possession of BJ94-like H9N2 internal genes resulted in more rapid transmission and significantly elevated cloacal shedding compared to the parental Anhui/13 H7N9. In vitro analysis showed that the 2:6 H7N9 with BJ94-like internal genes had significantly increased replication compared to the Anhui/13 H7N9 in chicken cells. In vivo coinfection experiments followed, where chickens were coinfected with pairs of Anhui/13 H7N9 and a 2:6 H7N9 reassortant. During ensuing transmission events, the Anhui/13 H7N9 virus outcompeted 2:6 H7N9 AIVs with internal gene segments of BJ94-like or G1-like H9N2 viruses. Coinfection did lead to the emergence of novel reassortant genotypes that were transmitted to contact chickens. Some of the reassortant viruses had a greater replication in chicken and human cells compared to the progenitors. We demonstrated that the internal gene cassette determines the transmission fitness of H7N9 viruses in chickens, and the reassortment events can generate novel H7N9 genotypes with increased virulence in chickens and enhanced zoonotic potential. IMPORTANCE H9N2 avian influenza viruses (AIVs) are enzootic in poultry in different geographical regions. The internal genes of these viruses can be exchanged with other zoonotic AIVs, most notably the A/Anhui/1/2013-lineage H7N9, which can give rise to new virus genotypes with increased veterinary, economic and public health threats to both poultry and humans. We investigated the propensity of the internal genes of H9N2 viruses (G1 or BJ94) in the generation of novel reassortant H7N9 AIVs. We observed that the internal genes of H7N9 which were derivative of BJ94-like H9N2 virus have a fitness advantage compared to those from the G1-like H9N2 viruses for efficient transmission among chickens. We also observed the generation of novel reassortant viruses during chicken transmission which infected and replicated efficiently in human cells. Therefore, such emergent reassortant genotypes may pose an elevated zoonotic threat.
Assuntos
Coinfecção , Subtipo H7N9 do Vírus da Influenza A , Vírus da Influenza A Subtipo H9N2 , Influenza Aviária , Influenza Humana , Animais , Humanos , Subtipo H7N9 do Vírus da Influenza A/genética , Vírus da Influenza A Subtipo H9N2/genética , Galinhas , Vírus Reordenados/genética , Aves Domésticas , FilogeniaRESUMO
Newcastle Disease Virus (NDV) genotype VII is a highly pathogenic Orthoavulavirus that has caused multiple outbreaks among poultry in Egypt since 2011. This study aimed to observe the prevalence and genetic diversity of NDV prevailing in domestic and wild birds in Egyptian governorates. A total of 37 oropharyngeal swabs from wild birds and 101 swabs from domestic bird flocks including chickens, ducks, turkeys, and pelicans, were collected from different geographic regions within 13 governorates during 2019-2020. Virus isolation and propagation via embryonated eggs revealed 91 swab samples produced allantoic fluid containing haemagglutination activity, suggestive of virus presence. The use of RT-PCR targeted to the F gene successfully detected NDV in 85 samples. The geographical prevalence of NDV was isolated in 12 governorates in domestic birds, migratory, and non-migratory wild birds. Following whole genome sequencing, we assembled six NDV genome sequences (70-99% of genome coverage), including five full F gene sequences. All NDV strains carried high virulence, with phylogenetic analysis revealing that the strains belonged to class II within genotype VII.1.1. The genetically similar yet geographically distinct virulent NDV isolates in poultry and a wild bird may allude to an external role contributing to the dissemination of NDV in poultry populations across Egypt. One such contribution may be the migratory behaviour of wild birds; however further investigation must be implemented to support the findings of this study. Additionally, continued genomic surveillance in both wild birds and poultry would be necessary for monitoring NDV dissemination and genetic diversification across Egypt, with the aim of controlling the disease and protecting poultry production.
Assuntos
Doença de Newcastle , Doenças das Aves Domésticas , Animais , Doença de Newcastle/epidemiologia , Aves Domésticas , Egito/epidemiologia , Filogenia , Prevalência , Galinhas , Vírus da Doença de Newcastle , Animais Selvagens , Genótipo , Doenças das Aves Domésticas/epidemiologia , Animais DomésticosRESUMO
This paper reports a presumptive severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infection in a cat. A cat with respiratory disease living with three individuals with coronavirus disease 2019 showed bilateral ground-glass opacities in the lung on X-ray and computed tomography. The clinical swabs were negative for SARS-CoV-2 RNA, but the serum was positive for SARS-CoV-2 antibodies. Interstitial pneumonia and prominent type 2 pneumocyte hyperplasia were noted on histopathology. Respiratory tissues were negative for SARS-CoV-2 RNA or antigen, but the cat was positive for feline parvovirus DNA. In conclusion, the respiratory disease and associated pathology in this cat could have been due to exposure to SARS-CoV-2.