SARS-CoV-2 antibodies in dogs and cats in a highly infected area of Brazil during the pandemic.

SARS-CoV-2 was a worldwide threat during the COVID-19 pandemic, and the state of Mato Grosso had the second highest mortality rate in Brazil, with 427. 4 deaths/100,000 inhabitants. However, no large-scale study among dogs and cats in such highly infected areas of Brazil has so far been conducted. Accordingly, the present study reports on a serosurvey among dogs and cats in Cuiabá, capital of Mato Grosso from November 2020 to July 2021, where the human mortality rate was 605/100,000 at that time. Overall, 33/762 dogs (4.3%) and 4/182 cats (2.2%) were found to be seropositive for SARS-CoV-2 through ELISA, and 3/762 dogs (0.4%) and 3/182 cats (1.6%) were seropositive through the serum neutralization test. Cats presented higher seroprevalence with higher titers of neutralizing antibodies. Although N-protein based ELISA may be a good screening test, cross-reactivity with other canine coronaviruses may impair its diagnostic use among dogs.

Antibody prevalence of Leptospira spp. and Brucella abortus in domestic cats from Araguaína, Tocantins, North Region of Brazil / Prevalência de anticorpos para Leptospira spp. e Brucella Abortus em gatos domésticos de Araguaína, Tocantins, Região Norte do Brasil

Leptospira spp. and Brucella abortus are bacterial pathogens that can infect humans and animals. The present study aimed to detect anti-Leptospira and anti-B. abortus antibodies and verified the presence of factors associated with seropositivity in cats. One hundred and eighty serum samples were collected from domestic cats (Felis silvestris catus) from the urban area of the municipality of Araguaína-Tocantins by phlebocentesis of the cephalic and jugular veins. The samples were subjected to detection of anti-Leptospira and anti-B.abortus antibodies, respectively, by microscopic seroagglutination and buffered acidified antigen testing, followed by confirmation by the 2-mercaptoethanol test and slow seroagglutination in tubes. Data from the epidemiological questionnaire (the age, sex, origin, breed, and presence of clinical signs) were analyzed using Epi Info® software with seropositivity data found to search for associated factors using the chi-square test. In the present study, the prevalence of Leptospira spp. was 5.56% (10/180). However, no sample was reactive to B. abortus. None of the studied variables were associated with seropositivity for the pathogens evaluated. Therefore, there is contact between Leptospira spp. and the feline population of the municipality, indicating the possibility of the circulation of pathogenic serovars and that the presence of anti-Leptospira antibodies does not depend on the variables analyzed.

Leptospira spp. e Brucella abortus são patógenos bacterianos que podem infectar humanos e animais. O presente estudo teve como objetivo detectar anticorpos anti-Leptospira e anti-B.abortus e verificar a presença de fatores associados com a soropositividade em gatos. Foram coletadas 180 amostras de soro de gatos domésticos (Felis silvestris catus) da zona urbana do município de Araguaína-Tocantins por flebocentese das veias cefálica e jugular. As amostras foram submetidas à detecção de anticorpos anti-Leptospira e anti-B. abortus, respectivamente, por soroaglutinação microscópica e teste do antígeno acidificado tamponado, seguido de confirmação pelo teste de 2-mercaptoetanol e soroaglutinação lenta em tubos. Os dados do questionário epidemiológico (idade, sexo, procedência, raça e presença de sinais clínicos) foram analisados no software Epi Info® com os dados de soropositividade encontrados para pesquisa de fatores associados pelo teste do qui-quadrado. No presente estudo, a prevalência de Leptospira spp. foi de 5,56% (10/180). No entanto, nenhuma amostra foi reativa para B. abortus. Nenhuma das variáveis estudadas foi associada com a soropositividade para os patógenos avaliados. Portanto, há contato entre Leptospiraspp. e a população felina do município, indicando a possibilidade de circulação de sorovares patogênicos e que a presença de anticorpos anti-Leptospira independe das variáveis analisadas.

Serological evidence for Saint Louis encephalitis virus in free-ranging New World monkeys and horses within the upper Paraná River basin region, Southern Brazil.

INTRODUCTION: Saint Louis encephalitis virus (SLEV) primarily occurs in the Americas and produces disease predominantly in humans. This study investigated the serological presence of SLEV in nonhuman primates and horses from southern Brazil. METHODS: From June 2004 to December 2005, sera from 133 monkeys (Alouatta caraya, n=43; Sapajus nigritus, n=64; Sapajus cay, n=26) trap-captured at the Paraná River basin region and 23 blood samples from farm horses were obtained and used for the serological detection of a panel of 19 arboviruses. All samples were analyzed in a hemagglutination inhibition (HI) assay; positive monkey samples were confirmed in a mouse neutralization test (MNT). Additionally, all blood samples were inoculated into C6/36 cell culture for viral isolation. RESULTS: Positive seroreactivity was only observed for SLEV. A prevalence of SLEV antibodies in sera was detected in Alouatta caraya (11.6%; 5/43), Sapajus nigritus (12.5%; 8/64), and S. cay (30.8%; 8/26) monkeys with the HI assay. Of the monkeys, 2.3% (1/42) of A. caraya, 6.3% 94/64) of S. nigritus, and 15.4% (4/26) of S. cay were positive for SLEV in the MNT. Additionally, SLEV antibodies were detected by HI in 39.1% (9/23) of the horses evaluated in this study. Arboviruses were not isolated from any blood sample. CONCLUSIONS: These results confirmed the presence of SLEV in nonhuman primates and horses from southern Brazil. These findings most likely represent the first detection of this virus in nonhuman primates beyond the Amazon region. The detection of SLEV in animals within a geographical region distant from the Amazon basin suggests that there may be widespread and undiagnosed dissemination of this disease in Brazil.

Serological evidence for Saint Louis encephalitis virus in free-ranging New World monkeys and horses within the upper Paraná River basin region, Southern Brazil

Introduction Saint Louis encephalitis virus (SLEV) primarily occurs in the Americas and produces disease predominantly in humans. This study investigated the serological presence of SLEV in nonhuman primates and horses from southern Brazil. Methods From June 2004 to December 2005, sera from 133 monkeys (Alouatta caraya, n=43; Sapajus nigritus, n=64; Sapajus cay, n=26) trap-captured at the Paraná River basin region and 23 blood samples from farm horses were obtained and used for the serological detection of a panel of 19 arboviruses. All samples were analyzed in a hemagglutination inhibition (HI) assay; positive monkey samples were confirmed in a mouse neutralization test (MNT). Additionally, all blood samples were inoculated into C6/36 cell culture for viral isolation. Results Positive seroreactivity was only observed for SLEV. A prevalence of SLEV antibodies in sera was detected in Alouatta caraya (11.6%; 5/43), Sapajus nigritus (12.5%; 8/64), and S. cay (30.8%; 8/26) monkeys with the HI assay. Of the monkeys, 2.3% (1/42) of A. caraya, 6.3% 94/64) of S. nigritus, and 15.4% (4/26) of S. cay were positive for SLEV in the MNT. Additionally, SLEV antibodies were detected by HI in 39.1% (9/23) of the horses evaluated in this study. Arboviruses were not isolated from any blood sample. Conclusions These results confirmed the presence of SLEV in nonhuman primates and horses from southern Brazil. These findings most likely represent the first detection of this virus in nonhuman primates beyond the Amazon region. The detection of SLEV in animals within a geographical region distant from the Amazon basin suggests that there may be widespread and undiagnosed dissemination of this disease in Brazil. .

Validation of a PCR Assay for Chlamydophila abortus rRNA gene detection in a murine model

Chlamydophila abortus (C. abortus) is associated with reproductive problems in cattle, sheep, and goats. Diagnosis of C. abortus using embryonated chicken eggs or immortalized cell lines has a very low sensitivity. Polymerase chain reaction (PCR) assays have been used to detect C. abortus infection in clinical specimens and organ fragments, such as placenta, fetal organs, vaginal secretions, and semen. The aim of this study was to develop a PCR assay for the amplification of an 856-bp fragment of the rRNA gene of the Chlamydiaceae family. The PCR assay was evaluated using organs from 15 mice experimentally infected with the S26/3 reference strain of C. abortus. The results of the rRNA PCR were compared to the results from another PCR system (Omp2 PCR) that has been previously described for the Omp2 (outer major protein) gene from the Chlamydiaceae family. From the 15 C. abortus-inoculated mice, 13 (K=0.84, standard error =0.20) tested positive using the rRNA PCR assay and 9 (K=0.55, standard error=0.18) tested positive using the Omp2 PCR assay. The detection limit, measured using inclusion-forming units (IFU), for C. abortus with the rRNA PCR (1.05 IFU) was 100-fold lower than for the Omp2 PCR (105 IFU). The higher sensitivity of the rRNA PCR, as compared to the previously described PCR assay, and the specificity of the assay, demonstrated using different pathogenic microorganisms of the bovine reproductive system, suggest that the new PCR assay developed in this study can be used for the molecular diagnosis of C. abortus in abortion and other reproductive failures in bovines, caprines, and ovines.

Chlamydophila abortus (C. abortus) é frequentemente associada a distúrbios reprodutivos em bovinos, ovinos e caprinos. Para o diagnóstico, os métodos de cultivo em ovo embrionado de galinha e em células de linhagem contínua apresentam baixa sensibilidade. A reação em cadeia da polimerase (PCR) tem sido utilizada em placenta, órgãos fetais, secreção vaginal e sêmen para o diagnóstico da C. abortus. O objetivo deste trabalho foi desenvolver um sistema de PCR para a amplificação de um fragmento de 856-pb do gene rRNA da família Chlamydiaceae. A PCR foi avaliada em órgãos de 15 camundongos infectados experimentalmente com a estirpe de referência S26/3 da C. abortus. Os resultados foram comparados com os obtidos em outro sistema de PCR, previamente descrito para o gene Omp2 (outer major protein) da família Chlamydiaceae. Dos 15 camundongos inoculados com C. abortus, 13 (K=0,84, erro padrão=0,20) foram positivos na rRNA PCR e nove (K=0,55, erro padrão=0,18) na Omp2 PCR. O limite de detecção da C. abortus na rRNA PCR (1,05 UFI) foi 100 vezes inferior à Omp2 PCR (105 UFI). A maior sensibilidade em comparação ao sistema de PCR anteriormente descrito, bem como a especificidade demonstrada frente a diferentes microrganismos patogênicos do sistema reprodutivo, abrem a perspectiva da utilização da PCR desenvolvida nesse estudo para o diagnóstico molecular da C. abortus em casos de abortamentos e outros distúrbios reprodutivos em bovinos, ovinos e caprinos.

Investigation of the possible role of Chlamydophila abortus in reproductive failures in nrazilian herds of domestic ruminants

Chlamydophila abortus (C. abortus) infection is related to reproductive failure in domestic ruminants. Although it has not been well characterized worldwide, this pathogen has already been identified in some European countries and in the USA. In Brazil, preliminary studies have shown serological evidence of C. abortus infection in herds with low antibody prevalence. Until now, the identification of C. abortus in biological samples from females presenting reproductive failures has not been described in Brazilian herds of domestic ruminants. The aim of this study was to evaluate the presence of the C. abortus in a collection of abortions from cattle (n=85), sheep (n=12), and goats (n=8), in samples of vaginal mucus from cows (n=13), sheep (n=90), and goats (n­=20), and in semen from sheep (n=10) and goats (n=5). The specimens (n=243) were evaluated using a PCR assay developed to amplify the 16S-23S rRNA intergenic space of C. abortus. A PCR assay with an internal control, which amplifies a fragment from the ND5 gene of bovine mitochondrial DNA, was used in order to evaluate the efficiency of the DNA extraction and of the PCR reaction. All biological samples (n=243) included in this study were negative for C. abortus in the PCR assay. The internal control enabled the amplification of a product from the bovine mitochondrial ND5 gene in all cattle abortion samples (n=85). Given the serological evidence indicating the presence of C. abortus infection in Brazilian herds of domestic ruminants, and considering the wide sampling evaluated, the failure to identify C. abortus in this survey suggests that the frequency of clinical signs in infected animals may be low or even absent.

A infecção pela Chlamydophila abortus (C. abortus) em ruminantes domésticos está relacionada com distúrbios reprodutivos. Apesar de ainda pouco estudada em todo o mundo, a infecção já foi identificada em alguns países europeus e também nos EUA. No Brasil, estudos preliminares demonstraram evidências sorológicas da infecção em alguns rebanhos com baixa prevalência de anticorpos. Até o momento ainda não foi possível a identificação de C. abortus a partir de material biológico proveniente de fêmeas com problemas reprodutivos em rebanhos brasileiros. O objetivo deste trabalho foi avaliar a presença da C. abortus em uma coleção de abortos bovinos (n=85), ovinos (n=12) e caprinos (n=8), em amostras de muco vaginal bovino (n=13), ovino (n=90) e caprino (n=20), e em sêmen ovino (n=10) e caprino (n=5). As amostras biológicas (n=243) foram avaliadas por meio de técnica de PCR desenvolvida para a amplificação do espaço intergênico 16S-23S RNAr da C. abortus. Um controle interno da reação, que amplifica um fragmento do gene ND5 do DNA mitocondrial de bovino, foi utilizado para a avaliação da eficiência da extração e da amplificação do DNA nas amostras provenientes de abortamento bovino. Todas as amostras biológicas (n=243) incluídas nesse estudo resultaram negativas para a C. abortus na PCR. O controle interno da reação possibilitou a amplificação de um produto do gene ND5 mitocondrial bovino em todas as amostras de aborto bovino (n=85). Apesar de evidências,,sorológicas indicarem a presença da infecção por C. abortus em rebanhos de ruminantes no Brasil, e considerando o número de amostras biológicas avaliadas, a não identificação de C. abortus nesse estudo sugere que a frequência de sinais clínicos nos animais infectados pode ser baixa ou mesmo ausente.