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1.
PLoS One ; 15(8): e0236754, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-32756590

RESUMO

The antimalarial agent mefloquine is currently being investigated for its potential to inhibit feline coronavirus and feline calicivirus infections. A simple, high pressure liquid chromatography assay was developed to detect mefloquine plasma concentrations in feline plasma. The assay's lower limit of quantification was 250 ng/mL. The mean ± standard deviation intra- and inter-day precision expressed as coefficients of variation were 6.83 ± 1.75 and 5.33 ± 1.37%, respectively, whereas intra- and inter-day accuracy expressed as a percentage of the bias were 11.40 ± 3.73 and 10.59 ± 3.88%, respectively. Accordingly, this validated assay should prove valuable for future in vivo clinical trials of mefloquine as an antiviral agent against feline coronavirus and feline calicivirus. However, the proportion of mefloquine binding to feline plasma proteins has not been reported. The proportion of drug bound to plasma protein binding is an important concept when developing drug dosing regimens. As cats with feline infectious peritonitis (FIP) demonstrate altered concentrations of plasma proteins, the proportion of mefloquine binding to plasma proteins in both clinically normal cats and FIP-affected cats was also investigated. An in vitro method using rapid equilibrium dialysis demonstrated that mefloquine was highly plasma protein bound in both populations (on average > 99%).


Assuntos
Calicivirus Felino/efeitos dos fármacos , Coronavirus Felino/efeitos dos fármacos , Peritonite Infecciosa Felina/tratamento farmacológico , Mefloquina/farmacologia , Animais , Proteínas Sanguíneas/genética , Infecções por Caliciviridae/tratamento farmacológico , Infecções por Caliciviridae/veterinária , Infecções por Caliciviridae/virologia , Calicivirus Felino/patogenicidade , Gatos , Coronavirus Felino/patogenicidade , Peritonite Infecciosa Felina/sangue , Peritonite Infecciosa Felina/virologia , Ligação Proteica/efeitos dos fármacos
2.
Viruses ; 12(7)2020 06 28.
Artigo em Inglês | MEDLINE | ID: mdl-32605306

RESUMO

Novel severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), influenza A virus (IAV), and norovirus (NV) are highly contagious pathogens that threaten human health. Here we focused on the antiviral potential of the medicinal herb, Saxifraga spinulosa (SS). Water-soluble extracts of SS were prepared, and their virus-inactivating activity was evaluated against the human virus pathogens SARS-CoV-2 and IAV; we also examined virucidal activity against feline calicivirus and murine norovirus, which are surrogates for human NV. Among our findings, we found that SS-derived gallocatechin gallate compounds were capable of inactivating all viruses tested. Interestingly, a pyrogallol-enriched fraction (Fr 1C) inactivated all viruses more rapidly and effectively than did any of the component compounds used alone. We found that 25 µg/mL of Fr 1C inactivated >99.6% of SARS-CoV-2 within 10 s (reduction of ≥2.33 log10 TCID50/mL). Fr 1C resulted in the disruption of viral genomes and proteins as determined by gel electrophoresis, electron microscopy, and reverse transcription-PCR. Taken together, our results reveal the potential of Fr 1C for development as a novel antiviral disinfectant.


Assuntos
Antivirais/farmacologia , Betacoronavirus/efeitos dos fármacos , Vírus da Influenza A/efeitos dos fármacos , Norovirus/efeitos dos fármacos , Extratos Vegetais/farmacologia , Plantas Medicinais , Saxifragaceae , Betacoronavirus/ultraestrutura , Calicivirus Felino/efeitos dos fármacos , Eletroforese em Gel de Poliacrilamida , Genoma Viral/efeitos dos fármacos , Testes de Hemaglutinação , Humanos , Microscopia Eletrônica de Transmissão , Reação em Cadeia da Polimerase Via Transcriptase Reversa , Proteínas Virais/efeitos dos fármacos
3.
PLoS One ; 15(4): e0230975, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-32287278

RESUMO

Feline infectious peritonitis (FIP) is a systemic, fatal, viral-induced, immune-mediated disease of cats caused by feline infectious peritonitis virus (FIPV). Mefloquine, a human anti-malarial agent, has been shown to inhibit FIPV in vitro. As a first step to evaluate its efficacy and safety profile as a potential FIP treatment for cats, mefloquine underwent incubation in feline, canine and common brush-tailed possum microsomes and phase I metabolism cofactors to determine its rate of phase I depletion. Tramadol was used as a phase I positive control as it undergoes this reaction in both dogs and cats. Using the substrate depletion method, the in vitro intrinsic clearance (mean ± S.D.) of mefloquine by pooled feline and common brush-tailed possum microsomes was 4.5 ± 0.35 and 18.25 ± 3.18 µL/min/mg protein, respectively. However, phase I intrinsic clearance was too slow to determine with canine microsomes. Liquid chromatography-mass spectrometry (LC-MS) identified carboxymefloquine in samples generated by feline microsomes as well as negative controls, suggesting some mefloquine instability. Mefloquine also underwent incubation with feline, canine and common brush-tailed possum microsomes and phase II glucuronidative metabolism cofactors. O-desmethyltramadol (ODMT or M1) was used as a positive control as it undergoes a phase II glucuronidation reaction in these species. The rates of phase II mefloquine depletion by microsomes by all three species were too slow to estimate. Therefore mefloquine likely undergoes phase I hepatic metabolism catalysed by feline and common brush-tailed possum microsomes but not phase II glucuronidative metabolism in all three species and mefloquine is not likely to have delayed elimination in cats with clinically normal, hepatic function.


Assuntos
Antimaláricos/metabolismo , Mefloquina/metabolismo , Microssomos Hepáticos/metabolismo , Trichosurus/metabolismo , Animais , Antimaláricos/farmacocinética , Antivirais/metabolismo , Antivirais/farmacocinética , Infecções por Caliciviridae/tratamento farmacológico , Infecções por Caliciviridae/metabolismo , Infecções por Caliciviridae/veterinária , Calicivirus Felino , Gatos , Coronavirus Felino , Cães , Reposicionamento de Medicamentos/veterinária , Peritonite Infecciosa Felina/tratamento farmacológico , Peritonite Infecciosa Felina/metabolismo , Peritonite Infecciosa Felina/virologia , Técnicas In Vitro , Mefloquina/farmacocinética , Taxa de Depuração Metabólica , Especificidade da Espécie
4.
Int J Nanomedicine ; 15: 1387-1395, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-32184593

RESUMO

Introduction: A previous study demonstrated the virucidal effect of an electrically charged disinfectant (CAC-717), which contains meso-structure nanoparticles, on enveloped viruses (influenza viruses). However, the effect of CAC-717 on other microorganisms and the mechanisms by which CAC-717 inactivates the microorganisms remain unclear. In this study, CAC-717 was further evaluated in terms of its biocidal and virucidal activity as well as its effect on bacterial and viral nucleic acids. Methods: The inactivation effects of CAC-717 against various microorganisms [non-enveloped virus, feline calicivirus (FCV); bacteria, Salmonella enterica and Escherichia coli] were investigated by comparing the viral titer of the medium tissue culture infectious dose (TCID50) and the D value (estimated treatment time required to reduce the number of microorganisms by 90%). Furthermore, the effects of CAC-717 on viral and bacterial genomic RNA/DNA were examined using a polymerase chain reaction (PCR). Results: Treatment of an equal volume of CAC-717 with cell lysate infected with a non-enveloped virus, feline calicivirus (FCV), reduced the TCID50. Viral titer dropped below the detection limit after 2 min of treatment. The D value of FCV was 0.256 min (average of multiple endpoint D values) and endpoint D value was 0.341 min. The D value for E. coli and S. enterica was 0.290 min and 0.080 min (average of multiple endpoint D values), respectively and the endpoint D value was 0.545 min and 0.054 min, respectively. In addition, PCR showed the inhibition of nucleic acid amplification of the RNA and DNA genome of FCV and bacteria, respectively. Conclusion: Our findings suggest that CAC-717 inactivates viruses and bacteria by modifying the viral and bacterial nucleic acids.


Assuntos
Bactérias/efeitos dos fármacos , Calicivirus Felino/efeitos dos fármacos , Desinfetantes/farmacologia , Genoma Bacteriano/efeitos dos fármacos , Genoma Viral/efeitos dos fármacos , Nanopartículas/administração & dosagem , Inativação de Vírus/efeitos dos fármacos , Animais , Bactérias/genética , Calicivirus Felino/genética , Gatos , Desinfetantes/química , Desinfecção/métodos , Eletricidade , Nanopartículas/química , Carga Viral/efeitos dos fármacos
5.
J Appl Microbiol ; 128(6): 1534-1546, 2020 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-31991509

RESUMO

AIMS: The objective was to evaluate the possible synergistic effect of cranberry juice (CJ) and commercial citrus extract (BS) against FCV-F9 viral titre in vitro in combination with γ-irradiation and to determinate the D10 values and radiosensitivity increase. METHODS AND RESULTS: Virus samples were treated with a formulation containing a mixture of BS or CJ. Results showed a D10 of 0·05, 0·42% and 1·34 kGy for the virus treated with the BS, the CJ and the irradiation alone respectively. Concentrations needed to reduce 6 log TCID50  ml-1 of viral titre were BS-0·3%, CJ-2·52% and 8·04 kGy. Irradiation combined with BS-0·01% and CJ-0·1% against FCV-F9 virus showed D10 values of 0·74 and 0·72 kGy, respectively, resulting in a viral radiosensitization of 1·28 and 1·50 for respective treatments. CONCLUSION: The higher viral radiosensitization observed after combining γ-irradiation with BS-0·01% and CJ-0·1% indicates that CJ and BS could be used as antiviral agents alone or in combination with γ-irradiation to prevent NoV outbreaks. SIGNIFICANCE AND IMPACT OF THE STUDY: Cranberry juice and BS could be used in hurdle approaches in combined treatment with γ-irradiation to assure food safety without a detrimental effect on nutritional value and maintain low processing cost.


Assuntos
Antivirais/farmacologia , Calicivirus Felino/fisiologia , Irradiação de Alimentos/métodos , Raios gama , Tolerância a Radiação/efeitos dos fármacos , Calicivirus Felino/efeitos dos fármacos , Calicivirus Felino/efeitos da radiação , Citrus/química , Relação Dose-Resposta a Droga , Relação Dose-Resposta à Radiação , Inocuidade dos Alimentos , Vaccinium macrocarpon/química
6.
Environ Sci Technol ; 54(5): 2851-2858, 2020 03 03.
Artigo em Inglês | MEDLINE | ID: mdl-31976661

RESUMO

The removal and inactivation of infectious human norovirus (HuNoV) is a major focus in water purification, but the effectiveness of disinfection processes on norovirus is largely unknown owing to the lack of a readily available infectivity assay. In particular, norovirus behavior through unit processes may be over- or underestimated using current approaches for assessing HuNoV infectivity (e.g., surrogates, molecular methods). Here, we fill a critical knowledge gap by estimating inactivation data for HuNoV after exposure to UV254, a commonly used disinfection process in the water industry. Specifically, we used a PCR-based approach that accurately tracks positive-sense single-stranded RNA virus inactivation without relying on culturing methods. We first confirmed that the approach is valid with a culturable positive-sense single-stranded RNA human virus, coxsackievirus B5, by applying both qPCR- and culture-based methods to measure inactivation kinetics with UV254 treatment. We then applied the qPCR-based method to establish a UV254 inactivation curve for HuNoV (inactivation rate constant = 0.27 cm2 mJ-1). Based on a comparison with previously published data, HuNoV exhibited similar UV254 susceptibility compared with other enteric single-stranded RNA viruses (e.g., Echovirus 12, feline calicivirus) but degraded much faster than MS2 (inactivation rate constant = 0.14 cm2 mJ-1). In addition to establishing a HuNoV inactivation rate constant, we developed an approach using a single qPCR assay that can be applied to estimate HuNoV inactivation in UV254 disinfection systems.


Assuntos
Infecções por Caliciviridae , Calicivirus Felino , Norovirus , Animais , Gatos , Desinfecção , Humanos , Inativação de Vírus
7.
Food Microbiol ; 85: 103307, 2020 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-31500711

RESUMO

Cold atmospheric-gaseous plasma (CAP) is an emerging non-thermal technology for decontamination of foodborne bacterial and viral pathogens. We obtained a >5 log10 reduction in the titer (TCID50) of feline calicivirus (FCV) on stainless steel discs and Romaine lettuce leaves after 3 min wet exposure to air plasma generated by a two-dimensional array of integrated coaxial-microhollow dielectric barrier discharge (2D-AICM-DBD). However, when human norovirus (HuNoV GII.4) was treated for 5 min under the same conditions, ~2.6 log10 (>99.5%) reduction in genome copy number was observed as measured by ethidium monoazide-coupled RT-qPCR (EMA-RT-qPCR). To assess this discrepancy, we studied CAP's effect on FCV by the cell culture method and by the EMA-coupled RT-qPCR method. It was found that the molecular titration method (EMA-RT-qPCR) underestimates the level of virus reduction by CAP. Additionally, the fecal matter present in HuNoV samples partially suppressed virucidal activity of CAP. Assuming that the lower virus reduction measured by EMA-RT-qPCR method compared to cell culture method for FCV is the same as for HuNoV, we can conclude that FCV may be used as a surrogate for HuNoV to assess the virucidal effect of CAP. CAP is able to inactivate 3.5 Log10 units of HuNoV at low titers after 2 min of exposure.


Assuntos
Fezes/virologia , Norovirus/efeitos dos fármacos , Gases em Plasma/farmacologia , Inativação de Vírus/efeitos dos fármacos , Azidas , Calicivirus Felino/efeitos dos fármacos , Calicivirus Felino/genética , Desinfecção/métodos , Humanos , Alface/virologia , Norovirus/genética , Reação em Cadeia da Polimerase em Tempo Real , Aço Inoxidável
8.
Parasit Vectors ; 12(1): 436, 2019 Sep 09.
Artigo em Inglês | MEDLINE | ID: mdl-31500667

RESUMO

BACKGROUND: The common bed bug, Cimex lectularius, is an obligatory blood-feeding ectoparasite that requires a blood meal to molt and produce eggs. Their frequent biting to obtain blood meals and intimate association with humans increase the potential for disease transmission. However, despite more than 100 years of inquiry into bed bugs as potential disease vectors, they still have not been conclusively linked to any pathogen or disease. This ecological niche is extraordinarily rare, given that nearly every other blood-feeding arthropod is associated with some type of human or zoonotic disease. Bed bugs rely on the bacteria Wolbachia as an obligate endosymbiont to biosynthesize B vitamins, since they acquire a nutritionally deficient diet, but it is unknown if Wolbachia confers additional benefits to its bed bug host. In some insects, Wolbachia induces resistance to viruses such as Dengue, Chikungunya, West Nile, Drosophila C and Zika, and primes the insect immune system in other blood-feeding insects. Wolbachia might have evolved a similar role in its mutualistic association with the bed bug. In this study, we evaluated the influence of Wolbachia on virus replication within C. lectularius. METHODS: We used feline calicivirus as a model pathogen. We fed 40 bed bugs from an established line of Wolbachia-cured and a line of Wolbachia-positive C. lectularius a virus-laden blood meal, and quantified the amount of virus over five time intervals post-feeding. The antibiotic rifampicin was used to cure bed bugs of Wolbachia. RESULTS: There was a significant effect of time post-feeding, as the amount of virus declined by ~90% over 10 days in both groups, but no significant difference in virus titer was observed between the Wolbachia-positive and Wolbachia-cured groups. CONCLUSIONS: These findings suggest that other mechanisms are involved in virus suppression within bed bugs, independent of the influence of Wolbachia, and our conclusions underscore the need for future research.


Assuntos
Percevejos-de-Cama/microbiologia , Percevejos-de-Cama/virologia , Calicivirus Felino/crescimento & desenvolvimento , Calicivirus Felino/isolamento & purificação , Interações Microbianas , Carga Viral , Wolbachia/crescimento & desenvolvimento , Animais
9.
J Antibiot (Tokyo) ; 72(12): 981-985, 2019 12.
Artigo em Inglês | MEDLINE | ID: mdl-31534199

RESUMO

Feline herpesvirus type 1 (FHV-1) causes a potentially fatal disease in cats. Through the use of virus inhibition and cytotoxicity assays, sinefungin, a nucleoside antibiotic, was assessed for its potential to inhibit the growth of FHV-1. Sinefungin inhibited in vitro growth of FHV-1 most significantly over other animal viruses, such as feline infectious peritonitis virus, equine herpesvirus, pseudorabies virus and feline calicivirus. Our results revealed that sinefungin specifically suppressed the replication of FHV-1 after its adsorption to the host feline kidney cells in a dose-dependent manner without obvious cytotoxicity to the host cells. This antibiotic can potentially offer a highly effective treatment for animals infected with FHV-1, providing alternative medication to currently available antiviral therapies.


Assuntos
Adenosina/análogos & derivados , Antivirais/farmacologia , Varicellovirus/efeitos dos fármacos , Adenosina/farmacologia , Adenosina/toxicidade , Animais , Antivirais/toxicidade , Calicivirus Felino/efeitos dos fármacos , Doenças do Gato/tratamento farmacológico , Gatos , Linhagem Celular , Coronavirus Felino/efeitos dos fármacos , Relação Dose-Resposta a Droga , Infecções por Herpesviridae/tratamento farmacológico , Infecções por Herpesviridae/veterinária , Herpesvirus Equídeo 1/efeitos dos fármacos , Herpesvirus Suídeo 1/efeitos dos fármacos , Cavalos , Rim/citologia , Rim/virologia , Testes de Toxicidade
10.
Int Immunopharmacol ; 75: 105714, 2019 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-31352323

RESUMO

Feline calicivirus (FCV) causes upper respiratory tract infections in felines and threatens the health of wild and domestic felines. Clinically, specific drugs to treat FCV have not yet been developed. Here, IgG was extracted from inactivated FCV-immunized horse sera. Equine F(ab')2 fragments were obtained from pepsin-digested IgG and then purified by protein-G column chromatography. In our study, equine immunoglobulin F(ab')2 fragments showed efficient neutralizing activity in vitro against FCV and had therapeutic and prophylactic effects in FCV-infected cats. The anti-FCV-specific F(ab')2 fragment can significantly alleviate the clinical symptoms of FCV-infected cats and reduce the viral loads of the trachea, lung and spleen. These results indicate that the F(ab')2 fragment prepared from inactivated FCV-immunized horses may be used as a prophylactic and therapeutic agent for diseases caused by FCV.


Assuntos
Infecções por Caliciviridae/terapia , Doenças do Gato/terapia , Cavalos/imunologia , Imunização Passiva , Fragmentos Fab das Imunoglobulinas/uso terapêutico , Animais , Anticorpos Antivirais/imunologia , Infecções por Caliciviridae/veterinária , Infecções por Caliciviridae/virologia , Calicivirus Felino/imunologia , Doenças do Gato/virologia , Gatos , Feminino , Imunoglobulina G/imunologia , Pulmão/virologia , Baço/virologia , Traqueia/virologia , Vacinas Virais
11.
Mar Drugs ; 17(7)2019 Jul 09.
Artigo em Inglês | MEDLINE | ID: mdl-31324025

RESUMO

Posidonia oceanica waste biomass has been valorised to produce extracts by means of different methodologies and their bioactive properties have been evaluated. Water-based extracts were produced using ultrasound-assisted and hot water methods and classified according to their ethanol-affinity (E1: ethanol soluble; E2: non-soluble). Moreover, a conventional protocol with organic solvents was applied, yielding E3 extracts. Compositional and structural characterization confirmed that while E1 and E3 extracts were mainly composed of minerals and lipids, respectively, E2 extracts were a mixture of minerals, proteins and carbohydrates. All the extracts showed remarkably high antioxidant capacity, which was not only related to phenolic compounds but also to the presence of proteins and polysaccharides. All E2 and E3 extracts inhibited the growth of several foodborne fungi, while only E3 extracts decreased substantially the infectivity of feline calicivirus and murine norovirus. These results show the potential of P. oceanica waste biomass for the production of bioactive extracts.


Assuntos
Alismatales/química , Anti-Infecciosos/farmacologia , Antioxidantes/farmacologia , Compostos Fitoquímicos/farmacologia , Extratos Vegetais/farmacocinética , Animais , Anti-Infecciosos/química , Anti-Infecciosos/isolamento & purificação , Antioxidantes/química , Antioxidantes/isolamento & purificação , Biomassa , Infecções por Caliciviridae/tratamento farmacológico , Infecções por Caliciviridae/virologia , Calicivirus Felino/efeitos dos fármacos , Gatos , Etanol/química , Doenças Transmitidas por Alimentos/microbiologia , Doenças Transmitidas por Alimentos/prevenção & controle , Humanos , Lipídeos/química , Lipídeos/isolamento & purificação , Lipídeos/farmacologia , Camundongos , Testes de Sensibilidade Microbiana , Fungos Mitospóricos/efeitos dos fármacos , Norovirus/efeitos dos fármacos , Fenóis/química , Fenóis/isolamento & purificação , Fenóis/farmacologia , Compostos Fitoquímicos/química , Compostos Fitoquímicos/isolamento & purificação , Extratos Vegetais/química , Extratos Vegetais/isolamento & purificação , Proteínas de Plantas/química , Proteínas de Plantas/isolamento & purificação , Proteínas de Plantas/farmacologia , Polissacarídeos/química , Polissacarídeos/isolamento & purificação , Polissacarídeos/farmacologia , Células RAW 264.7 , Solventes/química , Água/química
12.
Prev Vet Med ; 167: 32-38, 2019 Jun 01.
Artigo em Inglês | MEDLINE | ID: mdl-31027718

RESUMO

The aim of the study was to determine the seroprevalence of feline panleukopenia virus (FPV), feline herpesvirus type 1 (FHV-1) and feline calicivirus (FCV) in stray colony cats from Milan, Italy. Cats were divided in groups based on age, gender, reproductive status, health status and colony of origin. Blood samples were tested with an in-clinic ELISA test. The possible presence of a link between the antibody titre or the presence of seropositive results and the independent variables (age, gender, reproductive status, health status and colony location) was assessed by means of multinomial and univariate logistic regression models, respectively. Seroprevalence of 85.4% was reported for FCV. The diffusion of the other two pathogens in the cat population was much lower compared to FCV, with 45.7% and 37.1% seroprevalence observed for FPV and FHV-1, respectively. An increase of antibody titres from kitten to senior was generally observed for the three pathogens. Age was a statistically significant variable for FHV-1, with senior cats significantly associated with higher antibody titres and higher percentages of seropositive animals compared to younger age groups. Neutered cats had significantly higher antibody titres and showed significantly higher FHV-1 seroprevalences compared to sexually intact cats. Colonies from two of the nine administrative districts of Milan showed significantly higher FPV seroprevalences compared to the others. No other significant differences were observed. Our results, based on cats belonging to 70 different colonies located in urban areas far from each other, suggest that the three viruses circulate in the feline population of stray cats in Milan. The feline calicivirus represents the most common circulating pathogen, as observed also in other studies worldwide. Finally, our results suggest that stray cats may be not adequately protected against FPV, FHV-1 and FCV and vaccination could be a possible strategic solution, especially for FPV.


Assuntos
Anticorpos Antivirais/sangue , Infecções por Caliciviridae/veterinária , Panleucopenia Felina/sangue , Infecções por Herpesviridae/veterinária , Animais , Infecções por Caliciviridae/sangue , Infecções por Caliciviridae/epidemiologia , Infecções por Caliciviridae/imunologia , Calicivirus Felino/imunologia , Gatos , Panleucopenia Felina/epidemiologia , Panleucopenia Felina/imunologia , Vírus da Panleucopenia Felina/imunologia , Feminino , Herpesviridae/imunologia , Infecções por Herpesviridae/sangue , Infecções por Herpesviridae/epidemiologia , Infecções por Herpesviridae/imunologia , Itália , Masculino , Prevalência
13.
Artigo em Alemão | MEDLINE | ID: mdl-31013527

RESUMO

The main causative agents of feline upper respiratory tract disease (FURTD) are feline herpesvirus-1 (FHV-1) and feline calicivirus (FCV). These viral infections are common, especially in multiple cat households. Severely affected cats often need to be hospitalized. Intensive symptomatic therapy is important in the management of cats with FURTD. The use of antiviral drugs is limited in cats, as they are often ineffective or toxic when given systemically. Antiviral drugs are, therefore, mainly used locally for the treatment of FHV-1-associated eye changes. Famciclovir, however, is an effective drug for systemic therapy in cats with FHV-1-related clinical signs. For FCV, only few antiviral drugs are available. In a controlled study, the use of immunoglobulins in cats with FHV-1 and/or FCV infection reduced clinical signs of FURTD significantly faster.


Assuntos
Infecções por Caliciviridae/veterinária , Calicivirus Felino , Doenças do Gato/terapia , Infecções por Herpesviridae/veterinária , Infecções Respiratórias/veterinária , Varicellovirus , Doença Aguda , Animais , Antivirais/uso terapêutico , Infecções por Caliciviridae/terapia , Infecções por Caliciviridae/virologia , Doenças do Gato/virologia , Gatos , Infecções por Herpesviridae/terapia , Infecções por Herpesviridae/virologia , Infecções Respiratórias/terapia , Infecções Respiratórias/virologia
14.
Res Vet Sci ; 124: 46-51, 2019 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-30844542

RESUMO

Feline calicivirus (FCV) is a contagious viral pathogen that usually causes a mild, self-limiting respiratory disease. More recently, highly virulent FCV strains have emerged and have been associated with severe systemic infection, referred to as virulent systemic disease (VSD). The objective of this study is to report VSD cases in Italian cats along with the molecular characterization of two detected FCV strains. Three client-owned cats showed clinical signs resembling to those described for VSD cases. The cats were subjected to molecular investigations for detection of FCV and other feline pathogens. Histopathology and immunohistochemistry were performed on internal organs of one cat; molecular characterization of two detected FCV strains was obtained through sequence and phylogenetic analyses. Putative VS-FCV strains were detected in all three cats, which were co-infected with feline panleukopenia virus. The cat submitted to histopathology and immunohistochemistry displayed severe histological changes and FCV antigens in internal organs. Two Italian FCV strains, for which amplification of ORF2 was successful, were strictly related and formed a unique phylogenetic cluster. These viruses did not show consistent changes in the amino acid sequences with respect to reference VS-FCVs. The results of our study confirm that VS-FCV strains are circulating in Italy and that VSD diagnosis is complicated since both genetic and clinical markers have not been identified so far.


Assuntos
Infecções por Caliciviridae/veterinária , Calicivirus Felino/fisiologia , Proteínas do Capsídeo/genética , Doenças do Gato/fisiopatologia , Sequência de Aminoácidos , Animais , Infecções por Caliciviridae/fisiopatologia , Infecções por Caliciviridae/virologia , Calicivirus Felino/classificação , Calicivirus Felino/genética , Proteínas do Capsídeo/química , Proteínas do Capsídeo/metabolismo , Doenças do Gato/virologia , Gatos , Feminino , Itália , Masculino , Filogenia , Alinhamento de Sequência
15.
J Hosp Infect ; 102(3): 304-310, 2019 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-30797885

RESUMO

BACKGROUND: Vomiting is one way in which the body rids itself of harmful gastric contents rapidly. Whilst this process is generally beneficial for the emetic individual, it can pose significant infection control issues if they are infected with a highly communicable pathogen such as norovirus. It is not known how far norovirus could spread through vomiting while remaining viable, particularly in far-reaching droplets and splashes that might be missed during cleaning. AIM: To identify the potential level of dissemination of viable norovirus after simulated vomiting. METHODS: This study used a system called 'Vomiting Larry' to simulate vomiting with infection medium containing the norovirus surrogate feline calicivirus (FCV) as a worst-case scenario for distribution and survival of viruses after simulated vomiting. Air and floor samples were taken after simulated vomiting, and analysed for viable virus via plaque assay. Analysis of covariance investigated differences in FCV concentration by sample volume and location. FINDINGS: Whilst viable virus was not isolated from any air samples taken after simulated vomiting, FCV concentrations of ≥10 plaque-forming units/mL were recovered from almost all samples taken from the floor (88/90). These included small droplets of fluid that travelled 3 m away from the vomiting system. There was evidence that FCV concentration depended on both sample volume and location. CONCLUSION: This study suggests that norovirus can survive being ejected even within small far-reaching droplets at concentrations capable of eliciting infection. Such droplets could easily go unnoticed and be overlooked during cleaning, adding to the challenge of controlling norovirus outbreaks.


Assuntos
Infecções por Caliciviridae/transmissão , Calicivirus Felino/isolamento & purificação , Transmissão de Doença Infecciosa , Microbiologia Ambiental , Viabilidade Microbiana , Vômito , Calicivirus Felino/fisiologia , Modelos Teóricos , Vesivirus , Ensaio de Placa Viral
16.
Nature ; 565(7739): 377-381, 2019 01.
Artigo em Inglês | MEDLINE | ID: mdl-30626974

RESUMO

To initiate infection, many viruses enter their host cells by triggering endocytosis following receptor engagement. However, the mechanisms by which non-enveloped viruses escape the endosome are poorly understood. Here we present near-atomic-resolution cryo-electron microscopy structures for feline calicivirus both undecorated and labelled with a soluble fragment of its cellular receptor, feline junctional adhesion molecule A. We show that VP2, a minor capsid protein encoded by all caliciviruses1,2, forms a large portal-like assembly at a unique three-fold axis of symmetry, following receptor engagement. This assembly-which was not detected in undecorated virions-is formed of twelve copies of VP2, arranged with their hydrophobic N termini pointing away from the virion surface. Local rearrangement at the portal site leads to the opening of a pore in the capsid shell. We hypothesize that the portal-like assembly functions as a channel for the delivery of the calicivirus genome, through the endosomal membrane, into the cytoplasm of a host cell, thereby initiating infection. VP2 was previously known to be critical for the production of infectious virus3; our findings provide insights into its structure and function that advance our understanding of the Caliciviridae.


Assuntos
Calicivirus Felino/metabolismo , Calicivirus Felino/ultraestrutura , Proteínas do Capsídeo/metabolismo , Proteínas do Capsídeo/ultraestrutura , Microscopia Crioeletrônica , Molécula A de Adesão Juncional/ultraestrutura , Receptores Virais/ultraestrutura , Montagem de Vírus , Animais , Calicivirus Felino/química , Calicivirus Felino/crescimento & desenvolvimento , Proteínas do Capsídeo/química , Gatos , Linhagem Celular , Endossomos/metabolismo , Endossomos/virologia , Genoma Viral , Interações Hidrofóbicas e Hidrofílicas , Molécula A de Adesão Juncional/química , Molécula A de Adesão Juncional/metabolismo , Modelos Moleculares , Receptores Virais/química , Receptores Virais/metabolismo , Eletricidade Estática , Vírion/química , Vírion/genética , Vírion/metabolismo , Vírion/ultraestrutura
17.
Virology ; 527: 146-158, 2019 01 15.
Artigo em Inglês | MEDLINE | ID: mdl-30529563

RESUMO

Calicivirus infection causes intrinsic apoptosis, leading to viral propagation in the host. During murine norovirus infection, a reduction in the anti-apoptotic protein survivin has been documented. Here we report that in feline calicivirus infection, a downregulation of the anti-apoptotic proteins survivin and XIAP occur, which correlates with the translocation of the pro-apoptotic protein Smac/DIABLO from the mitochondria to the cytoplasm and the activation of caspase-3. Inhibition of survivin degradation by lactacystin treatment caused a delay in apoptosis progression, reducing virus release, without affecting virus production. However, the overexpression of survivin caused a negative effect in viral progeny production. Overexpression of the leader of the capsid protein (LC), but not of the protease-polymerase NS6/7, results in the downregulation of survivin and XIAP, caspase activation and mitochondrial damage. These results indicate that LC is responsible for the induction of apoptosis in transfected cells and most probably in FCV infection.


Assuntos
Apoptose , Infecções por Caliciviridae/metabolismo , Calicivirus Felino/fisiologia , Proteínas do Capsídeo/metabolismo , Regulação para Baixo , Survivina/genética , Proteínas Inibidoras de Apoptose Ligadas ao Cromossomo X/genética , Animais , Infecções por Caliciviridae/virologia , Proteínas do Capsídeo/química , Gatos , Linhagem Celular , Expressão Gênica , Interações Hospedeiro-Patógeno , Proteínas Mitocondriais/metabolismo , Transporte Proteico , Survivina/metabolismo , Proteínas Virais/biossíntese , Replicação Viral
18.
Virus Res ; 261: 1-8, 2019 02.
Artigo em Inglês | MEDLINE | ID: mdl-30543874

RESUMO

Cellular proteins have been identified to participate in calicivirus replication in association with viral proteins and/or viral RNAs. By mass spectrometry from pull-down assays, we identified several cellular proteins bound to the feline calicivirus (FCV) genomic RNA; among them the lipid raft-associated scaffold protein Annexin (Anx) A2. AnxA2 colocalizes with FCV NS6/7 protein and with the dsRNA in infected cells; moreover, it was found associated with the viral RNA in the membrane fraction corresponding to the replication complexes (RCs), suggesting its role during FCV replication. AnxA2-knockdown from CrFK cells prior to infection with FCV caused a delay in the cytopathic effect, a strong reduction of viral non-structural proteins and dsRNA production, and a decrease of FCV yield in both cell-associated and supernatant fractions. Taken together, these results indicate that AnxA2 associates to the genomic RNA of FCV and is required for an efficient FCV replication.


Assuntos
Anexina A2/metabolismo , Calicivirus Felino/fisiologia , Interações Hospedeiro-Patógeno , RNA Viral/metabolismo , Replicação Viral , Animais , Calicivirus Felino/crescimento & desenvolvimento , Gatos , Linhagem Celular , Efeito Citopatogênico Viral , Espectrometria de Massas , Ligação Proteica , RNA de Cadeia Dupla/metabolismo , Carga Viral , Proteínas não Estruturais Virais/metabolismo
19.
Sci Rep ; 8(1): 17947, 2018 12 18.
Artigo em Inglês | MEDLINE | ID: mdl-30560882

RESUMO

A dielectric barrier discharge (DBD) plasma torch has been used to evaluate the mechanism underlying inactivation of feline calicivirus (FCV) by plasma treatment. Plasma treatment of cell lysate infected with FCV F9 strain reduced the viral titer of the median tissue culture infectious dose (TCID50). The D value (treatment time required to lower the viral titer to 1/10) was 0.450 min, while the viral titer dropped below the detection limit within 2 min. FCV was not significantly inactivated by heat or UV applied at levels corresponding to those generated from the DBD plasma torch after 2 min (38.4 °C and 46.79 mJ/cm2 UV, respectively). However, TCID50 was reduced by 2.47 log after exposure to 4.62 mM ONOO-, corresponding to the concentration generated after 2 min of plasma treatment. Radical scavengers, including superoxide dismutase, dimethyl sulfoxide, and catalase, did not significantly affect viral titers; however, sodium azide, uric acid, and ascorbic acid, which are scavengers of 1O2 radicals, ONOO-, and peroxynitrous acid (ONOOH; produced from ONOO- under acidic conditions), respectively, significantly increased TCID50 and intact viral RNA. These findings suggest that ONOO- and 1O2 play an important role in FCV inactivation by attacking viral RNA during DBD plasma torch treatment.


Assuntos
Calicivirus Felino/efeitos dos fármacos , Calicivirus Felino/genética , Ácido Peroxinitroso/farmacologia , RNA Viral/efeitos dos fármacos , Oxigênio Singlete/farmacologia , Animais , Antivirais/farmacologia , Infecções por Caliciviridae/veterinária , Doenças do Gato/tratamento farmacológico , Doenças do Gato/virologia , Gatos , Linhagem Celular , Desinfetantes/farmacologia , Depuradores de Radicais Livres/farmacologia , Concentração Inibidora 50 , Carga Viral
20.
Res Vet Sci ; 121: 53-58, 2018 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-30359811

RESUMO

We investigated the clinical effectiveness of subcutaneous (SC) administration of recombinant feline interferon-omega (rFeIFN-ω) at a dose of 1 M unit (MU)/kg body weight (bw) for the treatment of feline chronic gingivitis-stomatitis (FCGS) in cats infected with feline calicivirus (FCV). Among the 17 cats used in this study, there were 13 FCV-positive cats (FCVI group), which were subcutaneously injected with rFeIFN-ω. The remaining four FCV-positive cats (FCVC group) were treated with SC corticosteroid. SC injection of rFeIFN-ω was given once daily on days 1, 2, 3, 7, 8, 9, 14, and 21. Corticosteroid was subcutaneously injected at a dose of 1.0 mg/kg bw, at the same intervals as rFeIFN-ω. Clinical symptoms (salivation, pain at opening the mouth, halitosis, mandibular lymphadenopathy, and all four symptoms combined [defined as "total clinical symptoms"]) and stomatitis (the degree and extent of inflammation, bleeding from the lesion, and all three items combined [defined as "total stomatitis"]) were scored on days 0, 7, 14, 21, and 28. FCV RNAs was quantified by real-time polymerase chain reaction and the percent increase in viral copy numbers was calculated using the values on days 0 and 28. In the FCVI group, significant differences were observed in the score for clinical symptom (salivation) score and in the total clinical symptom score within the group (P = 0.018 and 0.008, respectively). Significant differences within the group were also observed in the scores for the degree and extent of inflammation in stomatitis and in the total stomatitis score (P = 0.003, 0.007, and 0.003, respectively). The total score, defined as the clinical score plus the stomatitis score, was on days 7, 14, 21 and 28 than on day 0 (p = 0.006, .0003, 0.002 and 0.002, respectively). In the FCVI group, significant difference was observed between on days 0 and on 21 (p = 0.023). The percentage change in the number of polymerase chain reaction cycles required to amplify the viral RNA was positive (indicating viral reduction) in the FCVI group, but was negative in the FCVC group. These results demonstrate that SC administration of rFeIFN-ω under the current protocol improves stomatitis by inhibiting FCV proliferation in FCV-positive cats with FCGS.


Assuntos
Doenças do Gato/prevenção & controle , Gengivite/veterinária , Interferon Tipo I/uso terapêutico , Estomatite/veterinária , Animais , Infecções por Caliciviridae/veterinária , Infecções por Caliciviridae/virologia , Calicivirus Felino/fisiologia , Doenças do Gato/imunologia , Gatos , Feminino , Gengivite/imunologia , Gengivite/prevenção & controle , Inflamação/imunologia , Inflamação/prevenção & controle , Inflamação/veterinária , Injeções Subcutâneas/veterinária , Masculino , Distribuição Aleatória , Estomatite/imunologia , Estomatite/prevenção & controle
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