Your browser doesn't support javascript.
loading
Mostrar: 20 | 50 | 100
Resultados 1 - 20 de 253.340
Filtrar
1.
Artigo em Alemão | MEDLINE | ID: mdl-36323272

RESUMO

Although vaccines against canine parvovirus (CPV) are used worldwide, CPV infection still occurs relatively commonly, mainly in young dogs. This review article focuses on different causes of vaccination failures. Various factors affecting the dog itself or its environment can be responsible. A subset of dogs fail to develop antibodies (non-responders) or produce only very low antibody titers (low-responders) following vaccination against CPV for genetic reasons. In addition, vaccination efficacy can be affected by other intrinsic factors (e. g., weight, age, reproductive, and nutritional status, diseases) and/or extrinsic factors (e. g., stress, physical strain, medications). In addition to these causes affecting the individual dog, vaccine failure can also be caused by reduced immunizing properties of the vaccine itself. A variety of different factors (e. g., manufacturing, storage, application) can be responsible for this effect.


Assuntos
Doenças do Cão , Infecções por Parvoviridae , Parvovirus Canino , Vacinas Virais , Animais , Cães , Anticorpos Antivirais , Doenças do Cão/prevenção & controle , Doenças do Cão/virologia , Infecções por Parvoviridae/prevenção & controle , Infecções por Parvoviridae/veterinária , Vacinação/veterinária , Falha de Tratamento
2.
Biochemistry ; 61(22): 2495-2505, 2022 Nov 15.
Artigo em Inglês | MEDLINE | ID: mdl-36326185

RESUMO

The main protease (Mpro) of SARS-CoV-2 is essential for viral replication and has been the focus of many drug discovery efforts since the start of the COVID-19 pandemic. Nirmatrelvir (NTV) is an inhibitor of SARS-CoV-2 Mpro that is used in the combination drug Paxlovid for the treatment of mild to moderate COVID-19. However, with increased use of NTV across the globe, there is a possibility that future SARS-CoV-2 lineages will evolve resistance to NTV. Early prediction and monitoring of resistance mutations could allow for measures to slow the spread of resistance and for the development of new compounds with activity against resistant strains. In this work, we have used in silico mutational scanning and inhibitor docking of Mpro to identify potential resistance mutations. Subsequent in vitro experiments revealed five mutations (N142L, E166M, Q189E, Q189I, and Q192T) that reduce the potency of NTV and of a previously identified non-covalent cyclic peptide inhibitor of Mpro. The E166M mutation reduced the half-maximal inhibitory concentration (IC50) of NTV 24-fold and 118-fold for the non-covalent peptide inhibitor. Our findings inform the ongoing genomic surveillance of emerging SARS-CoV-2 lineages.


Assuntos
Antivirais , COVID-19 , Proteases 3C de Coronavírus , Farmacorresistência Viral , Inibidores de Proteases , SARS-CoV-2 , Humanos , Antivirais/farmacologia , Antivirais/química , COVID-19/tratamento farmacológico , COVID-19/virologia , Simulação de Acoplamento Molecular , Mutação , Pandemias , Inibidores de Proteases/farmacologia , Inibidores de Proteases/química , SARS-CoV-2/efeitos dos fármacos , SARS-CoV-2/genética , Farmacorresistência Viral/genética , Proteases 3C de Coronavírus/antagonistas & inibidores
3.
PLoS One ; 17(11): e0277038, 2022.
Artigo em Inglês | MEDLINE | ID: mdl-36322603

RESUMO

BACKGROUND: Aedes aegypti and Aedes albopictus are primary vectors of emerging or re-emerging arboviruses that threaten public health worldwide. Many efforts have been made to develop interventions to control these Aedes species populations. Still, countries in the Latin America and the Caribbean (LAC) region struggle to create/design/develop sustainable and effective control strategies. This scoping review synthesises evidence concerning the effectiveness of Ae. aegypti and Ae. albopictus prevention and control interventions performed in LAC (2000-2021). The findings can be used to evaluate, compare and develop more effective control strategies. METHODOLOGY: The review is based on the methodology by Joanna Briggs Institute for conducting a scoping review. The MEDLINE (via PubMed and Web of Science), Cochrane Library, Scopus, EMBASE and ScienceDirect databases were used to search for articles. Grey literature was searched from governmental and non-governmental organisation websites. Four reviewers independently screened all titles and abstracts and full-text of the articles using the Rayyan web application, based on pre-defined eligibility criteria. RESULTS: A total of 122 publications were included in the review. Most studies focused on dengue virus infection and data on Ae. aegypti. Entomological data were mainly used to determine the intervention's effectiveness. An integrated control intervention was the most commonly employed strategy in both regions. Biological control measures, environmental management, and health education campaigns on community participation achieved more sustainable results than an intervention where only a chemical control measure was used. Challenges to implementing interventions were insufficient financial support, resources, workforce, intersectoral collaboration and legislation. CONCLUSIONS: Based on the synthesised data, an integrated vector (Aedes) management focused on community participation seems to be the most effective approach to mitigate Aedes-borne infectious diseases. Maintaining the approach's effect remains challenging as it requires multisectoral and multi-disciplinary team engagement and active community participation. Future research needs to address the barriers to program implementation and maintenance as data on this topic is lacking.


Assuntos
Aedes , Controle de Doenças Transmissíveis , Mosquitos Vetores , Animais , Humanos , Aedes/virologia , Arbovírus , Dengue/epidemiologia , Dengue/prevenção & controle , Entomologia , América Latina/epidemiologia , Mosquitos Vetores/virologia , Região do Caribe/epidemiologia , Controle de Doenças Transmissíveis/métodos
4.
Front Immunol ; 13: 962079, 2022.
Artigo em Inglês | MEDLINE | ID: mdl-36389664

RESUMO

Despite the efficacy of antiviral drug repositioning, convalescent plasma (CP), and the currently available vaccines against severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), the worldwide coronavirus disease 2019 (COVID-19) pandemic is still challenging because of the ongoing emergence of certain new SARS-CoV-2 strains known as variants of concern (VOCs). Mutations occurring within the viral genome, characterized by these new emerging VOCs, confer on them the ability to efficiently resist and escape natural and vaccine-induced humoral and cellular immune responses. Consequently, these VOCs have enhanced infectivity, increasing their stable spread in a given population with an important fatality rate. While the humoral immune escape process is well documented, the evasion mechanisms of VOCs from cellular immunity are not well elaborated. In this review, we discussed how SARS-CoV-2 VOCs adapt inside host cells and escape anti-COVID-19 cellular immunity, focusing on the effect of specific SARS-CoV-2 mutations in hampering the activation of CD8+ T-cell immunity.


Assuntos
Linfócitos T CD8-Positivos , COVID-19 , Evasão da Resposta Imune , SARS-CoV-2 , Humanos , Linfócitos T CD8-Positivos/imunologia , COVID-19/imunologia , COVID-19/virologia , SARS-CoV-2/genética
5.
BMC Infect Dis ; 22(1): 820, 2022 Nov 07.
Artigo em Inglês | MEDLINE | ID: mdl-36344911

RESUMO

BACKGROUND: Influenza is responsible for more than 5 million severe cases and 290,000 to 650,000 deaths every year worldwide. Developing countries account for 99% of influenza deaths in children under 5 years of age. This paper aimed to determine the dynamics of influenza viruses in African transmission areas to identify regional seasonality for appropriate decision-making and the development of regional preparedness and response strategies. METHODS: We used data from the WHO FluMart website collected by National Influenza Centers for seven transmission periods (2013-2019). We calculated weekly proportions of positive influenza cases and determined transmission trends in African countries to determine the seasonality. RESULTS: From 2013 to 2019, influenza A(H1N1)pdm2009, A(H3N2), and A(H5N1) viruses, as well as influenza B Victoria and Yamagata lineages, circulated in African regions. Influenza A(H1N1)pdm2009 and A(H3N2) highly circulated in northern and southern Africa regions. Influenza activity followed annual and regional variations. In the tropical zone, from eastern to western via the middle regions, influenza activities were marked by the predominance of influenza A subtypes despite the circulation of B lineages. One season was identified for both the southern and northern regions of Africa. In the eastern zone, four influenza seasons were differentiated, and three were differentiated in the western zone. CONCLUSION: Circulation dynamics determined five intense influenza activity zones in Africa. In the tropics, influenza virus circulation waves move from the east to the west, while alternative seasons have been identified in northern and southern temperate zones. Health authorities from countries with the same transmission zone, even in the absence of local data based on an established surveillance system, should implement concerted preparedness and control activities, such as vaccination.


Assuntos
Vírus da Influenza A Subtipo H1N1 , Vírus da Influenza A Subtipo H3N2 , Virus da Influenza A Subtipo H5N1 , Vírus da Influenza B , Influenza Humana , Humanos , Vírus da Influenza A Subtipo H1N1/genética , Vírus da Influenza A Subtipo H1N1/isolamento & purificação , Vírus da Influenza A Subtipo H3N2/genética , Vírus da Influenza A Subtipo H3N2/isolamento & purificação , Virus da Influenza A Subtipo H5N1/genética , Virus da Influenza A Subtipo H5N1/isolamento & purificação , Vírus da Influenza B/genética , Vírus da Influenza B/isolamento & purificação , Influenza Humana/epidemiologia , Influenza Humana/transmissão , Influenza Humana/virologia , Estações do Ano , África/epidemiologia
6.
Viruses ; 14(11)2022 Oct 31.
Artigo em Inglês | MEDLINE | ID: mdl-36366518

RESUMO

The Omicron variant of SARS-CoV-2 spreads more easily than earlier variants, possibly as a result of a higher viral load in the upper respiratory tract and oral cavity. Hence, we investigated whether the Omicron variant generates a higher viral load than that of the Delta variant in saliva and nasopharynx. Both specimens were collected from 52 Omicron and 17 Delta cases at two time points one week apart and analyzed by qRT-PCR. Viral load was measured as 10 log RNA genome copies per 1000 human cells according to the WHO reference standard. We found that Omicron cases carried a higher viral load and had more sustained viral shedding compared to the Delta cases, especially in the nasopharynx.


Assuntos
COVID-19 , Saliva , Humanos , Nasofaringe/virologia , RNA Viral/genética , RNA Viral/análise , Saliva/virologia , SARS-CoV-2/genética , Carga Viral
7.
Viruses ; 14(11)2022 Nov 03.
Artigo em Inglês | MEDLINE | ID: mdl-36366540

RESUMO

Monitoring virus infections can be an important selection tool in honey bee breeding. A recent study pointed towards an association between the virus-free status of eggs and an increased virus resistance to deformed wing virus (DWV) at the colony level. In this study, eggs from both naturally surviving and traditionally managed colonies from across Europe were screened for the prevalence of different viruses. Screenings were performed using the phenotyping protocol of the 'suppressed in ovo virus infection' trait but with qPCR instead of end-point PCR and a primer set that covers all DWV genotypes. Of the 213 screened samples, 109 were infected with DWV, 54 were infected with black queen cell virus (BQCV), 3 were infected with the sacbrood virus, and 2 were infected with the acute bee paralyses virus. It was demonstrated that incidences of the vertical transmission of DWV were more frequent in naturally surviving than in traditionally managed colonies, although the virus loads in the eggs remained the same. When comparing virus infections with queen age, older queens showed significantly lower infection loads of DWV in both traditionally managed and naturally surviving colonies, as well as reduced DWV infection frequencies in traditionally managed colonies. We determined that the detection frequencies of DWV and BQCV in honey bee eggs were lower in samples obtained in the spring than in those collected in the summer, indicating that vertical transmission may be lower in spring. Together, these patterns in vertical transmission show that honey bee queens have the potential to reduce the degree of vertical transmission over time.


Assuntos
Vírus de RNA , Viroses , Vírus , Animais , Abelhas/virologia , Prevalência , Vírus de RNA/genética
8.
Viruses ; 14(11)2022 Nov 06.
Artigo em Inglês | MEDLINE | ID: mdl-36366559

RESUMO

New variants of SARS-CoV-2 continue to evolve. The novel SARS-CoV-2 variant of concern (VOC) B.1.1.529 (Omicron) was particularly menacing due to the presence of numerous consequential mutations. In this study, we reviewed about 12 million SARS-CoV-2 genomic and associated metadata using extensive bioinformatic approaches to understand how evolutionary and mutational changes affect Omicron variant properties. Subsampled global data based analysis of molecular clock in the phylogenetic tree showed 29.56 substitutions per year as the evolutionary rate of five VOCs. We observed extensive mutational changes in the spike structural protein of the Omicron variant. A total of 20% of 7230 amino acid and structural changes exclusive to Omicron's spike protein were detected in the receptor binding domain (RBD), suggesting differential selection pressures exerted during evolution. Analyzing key drug targets revealed mutation-derived differential binding affinities between Delta and Omicron variants. Nine single-RBD substitutions were detected within the binding site of approved therapeutic monoclonal antibodies. T-cell epitope prediction revealed eight immunologically important functional hotspots in three conserved non-structural proteins. A universal vaccine based on these regions may likely protect against all these SARS-CoV-2 variants. We observed key structural changes in the spike protein, which decreased binding affinities, indicating that these changes may help the virus escape host cellular immunity. These findings emphasize the need for continuous genomic surveillance of SARS-CoV-2 to better understand how novel mutations may impact viral spread and disease outcome.


Assuntos
Antivirais , COVID-19 , Evasão da Resposta Imune , SARS-CoV-2 , Humanos , Antivirais/farmacologia , Antivirais/uso terapêutico , COVID-19/imunologia , COVID-19/virologia , Mutação , Filogenia , SARS-CoV-2/efeitos dos fármacos , SARS-CoV-2/genética , Glicoproteína da Espícula de Coronavírus/genética , Proteínas do Envelope Viral/genética
10.
Water Res ; 226: 119183, 2022 Nov 01.
Artigo em Inglês | MEDLINE | ID: mdl-36244146

RESUMO

In wastewater treatment plants (WWTPs), the stable operation of biological wastewater treatment is strongly dependent on the stability of associated microbiota. Bacteriophages (phages), viruses that specifically infect bacteria and archaea, are highly abundant and diverse in WWTPs. Although phages do not have known metabolic functions for themselves, they can shape functional microbiota via various phage-host interactions to impact biological wastewater treatment. However, the developments of phage-host interaction in WWTPs and their impact on biological wastewater treatment are overlooked. Here, we review the current knowledge regarding the phage-host interactions in biological wastewater treatment, mainly focusing on the characteristics of different phage populations, the phage-driven changes in functional microbiota, and the potential driving factors of phage-host interactions. We also discuss the efforts required further to understand and manipulate the phage-host interactions in biological wastewater treatment. Overall, this review advocates more attention to the phage dynamics in WWTPs.


Assuntos
Bacteriófagos , Microbiota , Águas Residuárias , Purificação da Água , Archaea , Bactérias , Bacteriófagos/fisiologia , Águas Residuárias/microbiologia , Águas Residuárias/virologia
11.
Medicine (Baltimore) ; 101(42): e31029, 2022 Oct 21.
Artigo em Inglês | MEDLINE | ID: mdl-36281140

RESUMO

RATIONALE: Acute encephalopathy is a severe neurological complication of coronavirus disease 2019 (COVID-19). Most cases of acute encephalopathy associated with COVID-19 occur within several weeks of COVID-19 onset. We describe a case series of 6 patients who developed delayed encephalopathy (DE) after COVID-19. PATIENT CONCERNS AND DIAGNOSES: We evaluated patients who recovered from COVID-19 and showed acute disturbance of consciousness or focal neurological deficits without recurrence of pneumonitis. Six patients, 2 females and 4 males, with ages ranging from 65 to 83 years were included. Durations of hospitalization due to COVID-19 were between 25 and 44 days. The severity of COVID-19 was moderate in 5 and severe in 1 patient. Patients were rehospitalized for acute disturbance of consciousness concomitant with postural tremor and, abnormal behavior, hemiplegia, aphasia, or apraxia between 34 and 67 days after the onset of COVID-19. Chest computed tomography showed no exacerbation of pneumonitis. Brain magnetic resonance imaging showed no specific findings except in 1 patient with an acute lacunar infarction. Electroencephalogram demonstrated diffuse slowing in all patients. Repeat electroencephalogram after recovery from encephalopathy demonstrated normal in all patients. One of the 6 patients had cerebrospinal fluid (CSF) pleocytosis. CSF protein levels were elevated in all patients, ranging from 51 to 115 mg/dL. CSF interleukin-6 levels ranged from 2.9 to 10.9 pg/mL. The immunoglobulin index was 0.39 to 0.44. Qlim(alb) < QAlb indicating dysfunction of the blood-brain barrier was observed in all patients. Severe acute respiratory syndrome coronavirus 2 reverse transcription polymerase chain reaction of CSF was negative in all patients. Neuronal autoantibodies were absent in serum and CSF. INTERVENTIONS AND OUTCOMES: Immunotherapy including steroid pulses was administered to 3 patients; however, symptoms of encephalopathy resolved within several days in all patients, regardless of treatment with immunotherapy, and their consciousness levels were recovered fully. Notably, postural tremor remained for 2 weeks to 7 months. LESSONS: In our patients, DE after COVID-19 was characterized by symptoms of acute encephalopathy accompanied with tremor in the absence of worsening pneumonitis after the fourth week of COVID-19 onset. Our findings indicate blood-brain barrier dysfunction may contribute to the pathogenesis of DE after COVID-19.


Assuntos
Encefalopatias , COVID-19 , Idoso , Idoso de 80 Anos ou mais , Feminino , Humanos , Masculino , Autoanticorpos , Encefalopatias/diagnóstico , Encefalopatias/virologia , COVID-19/complicações , Tremor
12.
Arch Biochem Biophys ; 731: 109449, 2022 Nov 30.
Artigo em Inglês | MEDLINE | ID: mdl-36288761

RESUMO

Persistent infection of human papillomavirus (HPV) and immune escape are the main causes of cervical cancer. E6/E7 encoded by HPV16 may be closely related to carcinogenesis. HPV infection may upregulate PD-L1 expression, resulting in immune escape and cervical cancerigenesis. Evidence indicates that miRNAs may mediate the regulation of E6/E7 on PD-L1. Therefore, we aimed to screen the miRNA, and further verify its expression and functions. Bioinformatics approaches were used to screen the miRNAs that mediate the regulation of E6/E7 on PD-L1. The expression of the miRNA and PD-L1 in HPV+ and HPV- cervical cancer cells were compared, and the effect of E6E7 on them was evaluated. Then, the effect of the miRNA on PD-L1 was assessed by the Gain- and Loss-of-function test. Finally, in vivo experiments were conducted to verify the effects of the miRNA on tumor growth and survival of tumor-bearing mice. Six miRNAs were screened, of which miR-142-5p was identified. MiR-142-5p was downregulated and PD-L1 was upregulated in HPV- cells after transfection of E6, E7, or E6/E7. The rescue test showed that the upregulation of miR-142-5p attenuated the effect of E6/E7 on PD-L1. The reverse relationship between PD-L1 and miR-142-5p was confirmed. In vivo experiments suggest that miR-142-5p upregulation inhibits the growth of the transplanted tumors by targeting PD-L1. MiR-142-5p acts as a tumor suppressor in cervical cancer. HPV16 E6E7 may promote the immune escape of cervical cancer cells by regulating the miR-142-5p/PD-L1 axis. Using miR-142-5p in tumor immunotherapy as a new strategy is proposed.


Assuntos
MicroRNAs , Proteínas Oncogênicas Virais , Infecções por Papillomavirus , Neoplasias do Colo do Útero , Animais , Feminino , Humanos , Camundongos , Antígeno B7-H1/genética , Antígeno B7-H1/metabolismo , Papillomavirus Humano 16/genética , Papillomavirus Humano 16/metabolismo , MicroRNAs/metabolismo , Proteínas Oncogênicas Virais/genética , Proteínas Oncogênicas Virais/metabolismo , Infecções por Papillomavirus/complicações , Infecções por Papillomavirus/genética , Neoplasias do Colo do Útero/genética , Neoplasias do Colo do Útero/patologia , Neoplasias do Colo do Útero/virologia
14.
JAMA ; 328(17): 1730-1739, 2022 11 01.
Artigo em Inglês | MEDLINE | ID: mdl-36272098

RESUMO

Importance: Herpes simplex virus type 1 (HSV-1) is the leading cause of first-episode genital herpes in many countries. Objective: To inform counseling messages regarding genital HSV-1 transmission, oral and genital viral shedding patterns among persons with first-episode genital HSV-1 infection were assessed. The trajectory of the development of HSV-specific antibody and T-cell responses was also characterized. Design, Setting, and Participants: Prospective cohort followed up for up to 2 years, with 82 participants followed up between 2013 and 2018. Participants were recruited from sexual health and primary care clinics in Seattle, Washington. Persons with laboratory-documented first-episode genital HSV-1 infection, without HIV infection or current pregnancy, were referred for enrollment. Exposures: First-episode genital HSV-1 infection. Main Outcomes and Measures: Genital and oral HSV-1 shedding and lesion rates at 2 months, 11 months, and up to 2 years after initial genital HSV-1 infection. Participants self-collected oral and genital swabs for HSV polymerase chain reaction testing for 30 days at 2 and 11 months and up to 2 years after diagnosis of genital HSV-1. Blood samples were collected at serial time points to assess immune responses to HSV-1. Primary HSV-1 infection was defined as absent HSV antibody at baseline or evolving antibody profile using the University of Washington HSV Western Blot. HSV-specific T-cell responses were detected using interferon γ enzyme-linked immunospot. Results: Among the 82 participants, the median (range) age was 26 (16-64) years, 54 (65.9%) were women, and 42 (51.2%) had primary HSV-1 infection. At 2 months, HSV-1 was detected from the genital tract in 53 participants (64.6%) and in the mouth in 24 participants (29.3%). Genital HSV-1 shedding was detected on 275 of 2264 days (12.1%) at 2 months and declined significantly to 122 of 1719 days (7.1%) at 11 months (model-predicted rate, 6.2% [95% CI, 4.3%-8.9%] at 2 months vs 3.2% [95% CI, 1.8%-5.7%] at 11 months; relative risk, 0.52 [95% CI, 0.29-0.93]). Genital lesions were rare, reported on 65 of 2497 days (2.6%) at 2 months and 72 of 1872 days (3.8%) at 11 months. Oral HSV-1 shedding was detected on 88 of 2247 days (3.9%) at 2 months. Persons with primary HSV-1 infection had a higher risk of genital shedding compared with those with nonprimary infection (model-predicted rate, 7.9% [95% CI, 5.4%-11.7%] vs 2.9% [95% CI, 1.7%-5.0%]; relative risk, 2.75 [95% CI, 1.40-5.44]). Polyfunctional HSV-specific CD4+ and CD8+ T-cell responses were maintained during the follow-up period. Conclusions and Relevance: Genital HSV-1 shedding was frequent after first-episode genital HSV-1, particularly among those with primary infection, and declined rapidly during the first year after infection.


Assuntos
Infecções por HIV , Herpes Genital , Herpes Simples , Herpesvirus Humano 1 , Gravidez , Feminino , Humanos , Adulto , Pessoa de Meia-Idade , Masculino , Herpes Genital/virologia , Eliminação de Partículas Virais , Herpesvirus Humano 2 , Estudos Prospectivos , Genitália/patologia
15.
BMC Vet Res ; 18(1): 364, 2022 Oct 03.
Artigo em Inglês | MEDLINE | ID: mdl-36192746

RESUMO

BACKGROUND: Selecting American mink (Neovison vison) for tolerance to Aleutian mink disease virus (AMDV) has gained popularity in recent years, but data on the outcomes of this activity are scant. The objectives of this study were to determine the long-term changes in viremia, seroconversion and survival in infected mink. Mink were inoculated intranasally with a local isolate of Aleutian mink disease virus (AMDV) over 4 years (n = 1742). The animals had been selected for tolerance to AMDV for more than 20 years (TG100) or were from herds free of AMDV (TG0). The progenies of TG100 and TG0, and their crosses with 25, 50 and 75% tolerance ancestry were also used. Blood samples were collected from each mink up to 14 times until 1211 days post-inoculation (dpi) and were tested for viremia by PCR and for anti-AMDV antibodies by counter-immunoelectrophoresis (CIEP). Viremia and CIEP status were not considered when selecting replacements. Low-performing animals were pelted and the presence of antibodies in their blood and antibody titer were measured by CIEP, and viremia and viral DNA in seven organs (n = 936) were tested by PCR. RESULTS: The peak incidences of viremia (66.7%) and seropositivity (93.5%) were at 35 dpi. The incidence of viremia decreased over time while the incidence of seroconversion increased. The least-squares means of the incidence of PCR positive of lymph node (0.743) and spleen (0.656) were significantly greater than those of bone marrow, liver, kidneys, lungs and small intestine (0.194 to 0.342). Differences in tolerant ancestry were significant for every trait measured. Incidences of viremia over time, terminal viremia, seropositivity over time, AMDV DNA in organs and antibody titer were highest in the susceptible groups (TG0 or TG25) and lowest in the tolerant groups (TG100 or TG75). CONCLUSION: Previous history of selection for tolerance resulted in mink with reduced viral replication and antibody titer. Viremia had a negative effect and antibody production had a positive effect on survival and productivity.


Assuntos
Vírus da Doença Aleutiana do Vison , Doença Aleutiana do Vison , Anticorpos Antivirais , Formação de Anticorpos , Vison , Viremia , Doença Aleutiana do Vison/sangue , Doença Aleutiana do Vison/imunologia , Doença Aleutiana do Vison/mortalidade , Doença Aleutiana do Vison/virologia , Vírus da Doença Aleutiana do Vison/genética , Vírus da Doença Aleutiana do Vison/imunologia , Vírus da Doença Aleutiana do Vison/isolamento & purificação , Animais , Anticorpos Antivirais/sangue , Anticorpos Antivirais/imunologia , DNA Viral/análise , Feminino , Masculino , Vison/sangue , Vison/imunologia , Vison/virologia , Taxa de Sobrevida , Viremia/sangue , Viremia/imunologia , Viremia/veterinária , Viremia/virologia , Replicação Viral
16.
PLoS One ; 17(10): e0273148, 2022.
Artigo em Inglês | MEDLINE | ID: mdl-36190936

RESUMO

INTRODUCTION & BACKGROUND: Prolonged (duration >7 to 13 days) diarrhea (ProD) in under-five children is a universal health problem including Bangladesh. Data on epidemiology and associated or risk factors of ProD are limited, particularly in Bangladesh where a high burden of ProD is reported. This study intended to assess the case load of ProD and its associated or risk factors compared to acute diarrhea (AD, duration ≤7 days). METHODS: We analyzed the data collected between 1996-2014 from a hospital-based Diarrheal-Disease-Surveillance-System (DDSS) in the 'Dhaka Hospital' of International Centre for Diarrhoeal Diseases, Bangladesh (icddr,b). The DDSS enrolled a 2% systematic sample, regardless of age, sex, and diarrhea severity. The data included information on socio-demographic factors, environmental history, clinical characteristics, nutritional status, and diarrhea-pathogens. After cleaning of data, relevant information of 21,566 under-five children were available who reported with ≤13 days diarrhea (including AD and ProD), and their data were analyzed. Variables found significantly associated with ProD compared to AD in bi-variate analysis were used in logistic regression model after checking the multicollinearity between independent variables. RESULTS: The mean±SD age of the children was 14.9±11.7 months and 40.4% were female; 7.6% had ProD and 92.4% had AD. Age <12 months, mucoid- or bloody-stool, warmer months (April-September), drug used at home before seeking care from hospital, and history of diarrhea within last one month were found associated with ProD (p<0.05); however, rotavirus infection was less common in children with ProD (p<0.05). ProD children more often needed inpatient admission than AD children (14.4 vs. 6.3, p<0.001). Case fatality rate of ProD vs. AD was 0.3% (n = 5) vs. 0.1% (n- = 22) respectively (p = 0.051). CONCLUSION: A considerable proportion (7.6%) of under-five children reporting to icddr,b hospital suffered from ProD. Understanding the above-mentioned associated or risk factors is likely to help policy makers formulating appropriate strategies for alleviating the burden and effectively managing ProD in under-five children.


Assuntos
Diarreia , Infecções por Rotavirus , Bangladesh/epidemiologia , Pré-Escolar , Diarreia/epidemiologia , Diarreia/virologia , Feminino , Humanos , Lactente , Masculino , Fatores de Risco , Infecções por Rotavirus/complicações , Infecções por Rotavirus/epidemiologia
17.
PLoS One ; 17(10): e0274162, 2022.
Artigo em Inglês | MEDLINE | ID: mdl-36190999

RESUMO

Coxsackievirus B3 (CVB3) is a principal causative agent of viral myocarditis, meningitis and pancreatitis. There is no vaccine available for clinical use. It has been demonstrated that the primary molecular determinant of virulence phenotype is located in the 5' UTR of the viral genome. Translation initiation of CVB3 RNA is directed by the IRES element situated in the 5'UTR. In the present study, we analyse the effects of single point mutations introduced in different positions in the domain V of the IRES RNA of CVB3 wild type. We characterize in vitro virus replicative capacitiy and translation efficiency and we test in vivo virulence of different CVB3 mutants produced by the introduction of different mutations in the domain V of IRES by site-directed mutagenesis to abolish its structure. Our results demonstrate that all RNA mutants display different levels of decreased replication and translation initiation efficiency in vitro. The translation defect was correlated with significant reduced viral titer of mutant particles in comparison with the wild type. When inoculated in mice, mutant viruses were checked for inflammation and necrosis.In vitro and in vivo Findings strongly suggest that the most attenuated mutant strain could be considered a candidate for live-attenuated CVB3 vaccine.


Assuntos
Infecções por Coxsackievirus , Enterovirus Humano B , Regiões 5' não Traduzidas , Animais , Infecções por Coxsackievirus/virologia , Enterovirus Humano B/genética , Células HeLa , Humanos , Camundongos , Mutação , Conformação de Ácido Nucleico , RNA Viral/química , RNA Viral/genética , Replicação Viral/genética
18.
Int J Immunopathol Pharmacol ; 36: 3946320221133001, 2022.
Artigo em Inglês | MEDLINE | ID: mdl-36214233

RESUMO

INTRODUCTION: The B.1.1.529 (Omicron) variant of SARS-CoV-2 is the most antigenically unique SARS-CoV-2 variant of concern to date, which is currently widespread across the world. Omicron variant and its sublineages contain a plethora of mutations than other variants of concern, which increases their transmissibility and virulence. Concerns regarding potential immunological evasion have been reignited by emerging subvariants of the Omicron variant. Determining the effectiveness of Omicron-induced immunity and whether it is cross-protective against other variants is a crucial aspect of the research. METHOD: A systematic search of relevant articles until September 25, 2022, from databases such as PubMed, Scopus, Google Scholar, and ScienceDirect was done independently by two authors. A total of 11 articles discussing about immunological evasion of different Omicron subvariants were included in the study. RESULTS: Numerous studies have demonstrated that Omicron variant causes a restricted immune response after infection. Omicron infection boosts preexisting vaccine-induced immunity, but it may not be enough to establish widespread, cross-neutralizing humoral immunity in unvaccinated people. CONCLUSION: Due to co-circulation and the emergence of novel SARS-CoV-2 variants, findings highlight the importance of booster vaccinations for immune protection. More studies should focus on the efficacy of Omicron-induced immunity, its cross-protective properties against other variants, and development of a universal vaccine.


Assuntos
Vacinas contra COVID-19 , COVID-19 , SARS-CoV-2 , COVID-19/prevenção & controle , COVID-19/virologia , Humanos , Imunidade Humoral , SARS-CoV-2/genética
19.
Trop Biomed ; 39(3): 428-433, 2022 Sep 01.
Artigo em Inglês | MEDLINE | ID: mdl-36214440

RESUMO

Lack of knowledge about the type and prevalence of gastrointestinal symptoms as a clinical manifestation is one of the reasons for delayed diagnosis and treatment of COVID-19 patients. This review study aimed to systematically review the type and prevalence of gastrointestinal symptoms in COVID-19 patients. To study the gastrointestinal manifestations of COVID-19, we used the 06- PRISMA registered in the CAMARADES-NC3Rs Preclinical Systematic Review and Meta-Analysis Facility (SyRF) database. PubMed, Embase, Web of Science, Google Scholar, and Scopus databases were searched for publications on the gastrointestinal manifestations of COVID-19 with no publication time frame. Articles were found using the following terms and search strategy: ["COVID-19, Coronavirus, 2019-nCoV, Clinical SymptomsGastrointestinal or gastric or intestinal manifestations"]. Out of 27652 papers, 35 papers on a total of 6730 COVID-19 patients up to 2022 met the inclusion criteria. Remarkably, most articles (28 papers, 77.8%) were from China (77.8%). The most common gastrointestinal manifestations were nausea or vomiting (13.1%), diarrhea (11.05%), anorexia (8.7%), and abdominal pain (2.4%), respectively. The findings of the present review revealed that contrary to what was initially assumed in the COVID-19 outbreak, this infection does not manifest only as respiratory symptoms but also as gastrointestinal symptoms. Therefore, clinicians and gastroenterologists must be alert to these unusual cases and fecal-oral transmission during the COVID-19 pandemic and implement preventive strategies.


Assuntos
COVID-19 , Gastroenteropatias , COVID-19/complicações , Gastroenteropatias/epidemiologia , Gastroenteropatias/virologia , Humanos , Pandemias , SARS-CoV-2
20.
Plant Dis ; 106(11): 2773-2783, 2022 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-36191166

RESUMO

Between 2010 and 2018, sunflower plants exhibiting virus-like symptoms, including stunting, mottling, and chlorotic ringspots on leaves, were observed from commercial fields and research plots from four sites within three distinct counties of western Nebraska (Box Butte, Kimball, and Scotts Bluff). Near identical symptoms from field samples were reproduced on seedlings mechanically in the greenhouse on multiple occasions, confirming the presence of a sap-transmissible virus from each site. Symptomatic greenhouse-inoculated plants from the 2010 and 2011 Box Butte samples tested negative for sunflower mosaic virus (SuMV), sunflower chlorotic mottle virus (SuCMoV), and all potyviruses in general by ELISA and RT-PCR. Similar viral-like symptoms were later observed on plants in a commercial sunflower field in Kimball County in 2014, and again from volunteers in research plots in Scotts Bluff County in 2018. Samples from both of these years were again successfully reproduced on seedlings in the greenhouse as before following mechanical transmissions. Symptom expression for all years began 12 to 14 days after inoculation as mild yellow spots followed by the formation of chlorotic ringspots from the mottled pattern. The culture from 2014 tested negatively for three groups of nepoviruses via RT-PCR, ruling this group out. However, transmission electron microscopy assays of greenhouse-infected plants from both 2014 and 2018 revealed the presence of distinct, polyhedral virus particles. With the use of high throughput sequencing and RT-PCR, it was confirmed that the infections from both years were caused by a new virus in the tombusvirus genus and was proposed to be called Sunflower ring spot mottle virus (SuRSMV). Although the major objective of this project was to identify the causal agent of the disease, it became evident that the diagnostic journey itself, with all the barriers encountered on the 10-year trek, was actually more important and impactful than identification.


Assuntos
Helianthus , Tombusvirus , Helianthus/virologia , Nebraska , Doenças das Plantas/virologia , Plântula/virologia , Tombusvirus/classificação , Tombusvirus/genética , Tombusvirus/isolamento & purificação , RNA Viral/genética , Especificidade da Espécie
SELEÇÃO DE REFERÊNCIAS
DETALHE DA PESQUISA
...