Persistent SARS-CoV-2 antigen presence in multiple organs of a naturally infected cat from Brazil

Abstract Background: Severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) is the etiological agent of the disease coronavirus 2019 (COVID-19) in humans. SARS-CoV-2 has been identified in cats with or without clinical signs. Case presentation: We describe the pathological and molecular findings in a six-month-old asymptomatic cat with SARS-CoV-2 infection from Brazil, belonging to a human family with COVID-19 cases. The pool of nasopharynx and oropharynx swabs at day zero tested positive by RT-qPCR for SARS-CoV-2. No amplification resulted from molecular testing performed on days 7 and 14. The cat was hit by a car and died 43 days after the molecular diagnosis. Immunohistochemistry at post-mortem examination demonstrated nucleocapsid protein in samples from the lungs, kidneys, nasal conchae, trachea, intestine, brain and spleen. Conclusion: The present study has highlighted the possibility that viral antigens can be detected by immunohistochemistry in multiple organs six weeks after infection, although the same tissues tested negative by RT-PCR.

Persistent SARS-CoV-2 antigen presence in multiple organs of a naturally infected cat from Brazil

Background: Severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) is the etiological agent of the disease coronavirus 2019 (COVID-19) in humans. SARS-CoV-2 has been identified in cats with or without clinical signs. Case presentation: We describe the pathological and molecular findings in a six-month-old asymptomatic cat with SARS-CoV-2 infection from Brazil, belonging to a human family with COVID-19 cases. The pool of nasopharynx and oropharynx swabs at day zero tested positive by RT-qPCR for SARS-CoV-2. No amplification resulted from molecular testing performed on days 7 and 14. The cat was hit by a car and died 43 days after the molecular diagnosis. Immunohistochemistry at post-mortem examination demonstrated nucleocapsid protein in samples from the lungs, kidneys, nasal conchae, trachea, intestine, brain and spleen. Conclusion: The present study has highlighted the possibility that viral antigens can be detected by immunohistochemistry in multiple organs six weeks after infection, although the same tissues tested negative by RT-PCR.(AU)

Evaluation of the antiviral activities of Bacharis dracunculifolia and quercetin on Equid herpesvirus 1 in a murine model.

Equid herpesvirus 1 (EHV-1) is a pathogen of high economic importance in equine breeding operations around the world. EHV-1 infection causes respiratory, neurologic and reproductive disease. The absence of an efficient therapy has caught the attention of the scientific community and the therapeutic activities of natural products with its antivirals effects might be effective for the disease's treatment. Herein it was evaluated the prophylactic and therapeutic potential of quercetin and ethanolic extracts of Bacharis dracunculifolia formulations compared to Penciclovir® in an in vivo EHV-1 infection model. Six to seven-week-old female C57BL/6 mice were randomly organized into fifteen groups with six animals each. Ex-1 represents the treatment post-challenge groups to assess morbidity, mortality and weight variation. Ex-2 represents the animals that received treatment for 5 days post-challenge for lesion evaluation. In Ex-3 animals were treated prior to viral challenge to assess morbidity, mortality and weight variation. All mice in the treatment groups were challenged by intranasal inoculation of 3.0 × 105 TCID50 EHV-1. The quercetin and B. dracunculifolia treatment decreased morbimortality in post-challenge treatment (Ex-1) and EHV-1 related lesions (Ex-2). Treatment prior to viral challenge (Ex-3) did not show any significant results. Based on the results of the present study, both tested formulations are promising antiviral agents for the treatment of EHV-1 infection.

Inhibition of herpes simplex virus 1 (HSV-1) and poliovirus (PV-1) by bacteriocins from lactococcus lactis subsp. lactis and enterococcus durans strains isolated from goat milk.

Bacteriocins have unusual inhibitory activity, including antiviral properties, and this can be exploited to give alternative applications. Semi-purified bacteriocins of six lactic acid bacteria (LAB) strains isolated from goat milk (two Lactococcus lactis: GLc03 and GLc05, and four Enterococcus durans: GEn09, GEn12, GEn14 and GEn17) were tested for cytotoxicity in Vero cells (50% Cytotoxicity Concentration: CC50), and for their antiviral activities against herpes simplex virus 1 (HVS-1) and poliovirus (PV-1). Semi-purified bacteriocins presented low cytotoxicity, with CC50 varying from 256.2 µg/mL (GLc05) to 1084.5 µg/mL (GEn14). CC10 was determined for all isolates (GLc03: 36.9 µg/mL; GLc05: 51.2 µg/mL; GEn09: 88.1 µg/mL; GEn12: 99.9 µg/mL; GEn14: 275 µg/mL; and GEn17: 62.2 µg/mL) and considered for antiviral activity assays. Antiviral activity before virus adsorption was recorded against PV-1 for GLc05 (4.9%), GEn09 (3.4%), GEn12 (24.7%) and GEn17 (23.5%), and against HSV-1 for GEn12 (27.9%), GEn14 (58.7%) and GEn17 (39.2%). Antiviral activity after virus adsorption was identified against PV-1 for GLc05 (32.7%), GEn09 (91.0%), GEn12 (93.7%) and GEn17 (57.2%), and against HSV-1 for GEn17 (71.6%). The results obtained indicate the potential of some bacteriocins, particularly those produced by E. durans strains investigated in the present study, in viral inhibition and their application as new antiviral agents.

Surveillance of neutralizing antibodies against Bovine Herpesvirus 1 in cattle herds from different farming property systems / Distribuição de anticorpos neutralizantes contra o Herpesvirus bovino 1 em propriedades bovinas de diferentes sistemas de criação

The aim of this study was to investigate the presence of neutralizing antibodies against bovine herpesvirus 1 (BoHV-1) in 722 non-vaccinated animals from eight properties that use different farming systems (extensive, semi-confinement and confinement). Serum samples were subjected to neutralization tests in order to search for anti-BoHV-1 antibodies. Serological results were categorized as negative, low titer, intermediate titer or high titer. One property showed no positive samples; while other properties presented frequency of positive samples ranging from 17.95% to 86.96%. For animals raised under confinement, the number of positive samples and neutralizing antibody titers were lower compared to others, possibly due to good sanitary practices adopted by this type of system. Altogether, our results can contribute towards the understanding of the endemic infection in Brazil.

Este trabalho teve por objetivo avaliar a distribuição de anticorpos neutralizantes contra o herpesvirus bovino 1 (BoHV-1) em 722 animais não vacinados pertencentes a oito propriedades que utilizam diferentes sistemas de criação (extensivo, semi-confinamento e confinamento). As amostras sorológicas foram submetidas ao teste de soroneutralização para pesquisa de anticorpos anti-BoHV-1. Os resultados foram classificados em títulos negativo, baixo, médio e alto. Uma propriedade não apresentou amostras positivas, enquanto que nas demais propriedades a frequência de amostras positivas variou de 17,95% a 86,96%. Os animais do sistema de criação por confinamento apresentaram menor número de amostras positivas quando comparado aos animais do outros sistemas de criação, possivelmente devido às boas práticas sanitárias adotadas por esse sistema. Dessa forma, nossos resultados podem contribuir para o entendimento dessa infecção endêmica no Brasil.

First occurrence of Amblyomma ovale in the State of Rio Grande do Norte, Brazil.

This study aims to report the occurrence of parasitism by Amblyomma ovale (Koch, 1844) in dogs in the municipality of Apodi, Rio Grande do Norte, Brazil. Specimens were identified as being one female and two males of A. ovale, besides; the animal was infested by five females of Rhipicephalus (Boophilus) microplus and seven females and three males of R. sanguineus. The finding of A. ovale confirms results in the literature that these ticks, reported in several species of wild carnivores, can also infect dogs in Brazil. The distribution of this tick species in several Brazilian states has already been confirmed, but this is the first report in the State of Rio Grande do Norte. This finding highlights the risk of the carrying of emerging and re-emerging pathogens to peridomestic hosts are as, either because of the frequency of these ticks in wild environments or the presence of infected wild animals near peridomestic environments, exposing domestic dogs to parasitism by A. ovale ticks and, therefore, to agents potentially carried by this ectoparasite.

First occurrence of Amblyomma ovale in the State of Rio Grande do Norte, Brazil / Primeira ocorrência de Amblyomma ovale no Estado do Rio Grande do Norte, Brasil

This study aims to report the occurrence of parasitism by Amblyomma ovale (Koch, 1844) in dogs in the municipality of Apodi, Rio Grande do Norte, Brazil. Specimens were identified as being one female and two males of A. ovale, besides; the animal was infested by five females of Rhipicephalus (Boophilus) microplus and seven females and three males of R. sanguineus. The finding of A. ovale confirms results in the literature that these ticks, reported in several species of wild carnivores, can also infect dogs in Brazil. The distribution of this tick species in several Brazilian states has already been confirmed, but this is the first report in the State of Rio Grande do Norte. This finding highlights the risk of the carrying of emerging and re-emerging pathogens to peridomestic hosts are as, either because of the frequency of these ticks in wild environments or the presence of infected wild animals near peridomestic environments, exposing domestic dogs to parasitism by A. ovale ticks and, therefore, to agents potentially carried by this ectoparasite.

O presente estudo objetiva comunicar a ocorrência do parasitismo por Amblyomma ovale (Koch, 1844) em cão, no município de Apodi, Rio Grande do Norte, Brasil. Os exemplares foram identificados como sendo uma fêmea e dois machos de A. ovale, além destes, o animal estava parasitado por cinco fêmeas de Rhipicephalus (Boophilus) microplus, sete fêmeas e três machos de R. sanguineus. O encontro de A. ovale confirma os resultados da literatura de que esses carrapatos, relatados em várias espécies de carnívoros silvestres, também podem infestar cães no Brasil. Este carrapato tem sua distribuição confirmada em vários estados brasileiros, sendo este o primeiro relato no Estado do Rio Grande do Norte. Este achado alerta para o risco do carreamento de patógenos emergentes e re-emergentes para regiões peridomiciliares, seja devido a frequência destes carrapatos em ambientes silvestres ou da presença de animais silvestres parasitados próximos a ambientes peridomiciliares, expondo cães domésticos ao parasitismo por carrapatos A. ovale e, consequentemente, a agentes potencialmente veiculados por este ectoparasito.