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Rotavirus (RV) is considered a major cause of acute viral gastroenteritis in young animals. RV is classified into nine species, five of which have been identified in pigs. Most studies worldwide have highlighted diarrhoea outbreaks caused by RVA, which is considered the most important RV species. In the present study, we described the detection and characterization of porcine RVB as a primary causative agent of diarrhoea outbreaks in pig herds in Brazil. The study showed a high frequency (64/90; 71.1%) of RVB diagnosis in newborn piglets associated with marked histopathological lesions in the small intestines. Phylogenetic analysis of the VP7 gene of wild-type RVB strains revealed a high diversity of G genotypes circulating in one geographic region of Brazil. Our findings suggest that RVB may be considered an important primary enteric pathogen in piglets and should be included in the routine differential diagnosis of enteric diseases in piglets.

Bovine gammaherpesvirus 6 (BoGHV6), formerly known as bovine lymphotropic virus, is a member of the Macavirus genus, subfamily Gammaherpesvirinae, family Herpesviridae, that was initially associated with proliferative diseases in cattle. While the Macavirus genus contains agents, including alcelaphine gammaherpesvirus 1 (AlGHV1), ovine gammaherpesvirus 2 (OvGHV2), and caprine gammaherpesvirus-2 (CpGHV2), known to cause malignant catarrhal fever (MCF), and are collectively referred to as MCF virus (MCFV) group of organisms, diseases and/or clinical syndromes have not been associated with BoGHV6 and porcine lymphotropic herpesvirus (PLHV). This report investigated the occurrence of BoGHV6 in tissues of aborted dairy fetuses known to be infected by Histophilus somni to identify possible disease patterns associated with infection by this Macavirus. A nested-PCR (nPCR) assay was used to amplify the BoGHV6 polymerase gene from multiple tissues of 13 fetuses and the cow of one of these which were derived from seven dairy herds located in three geographical regions of Brazil. Direct sequencing confirmed the results of the nPCR assays. Additionally, all fetal tissues were previously investigated for the presence of H. somni, Listeria monocytogenes, Neospora caninum, Brucella abortus, Leptospira spp., bovine alphaherpesvirus 1, and bovine viral diarrhea virus (BVDV) by PCR and/or RT-PCR assays. The nPCR assay amplified BoGHV6 DNA from fetuses of most dairy herds (85.7%; 6/7) investigated, resulting in the amplification of BoGHV6 from 76.9% (10/13) of all fetuses evaluated from two geographical and important cattle-producing regions of Brazil. Furthermore, only BoGHV6 was identified in the spleen (n = 3), myocardium, and kidney (n = 2) of five fetuses, and BoGHV6 was the only agent associated with myocarditis in one of these. Nevertheless, dual, triple, and quadruple infections (including BVDV, B. abortus, and N. caninum) were identified in fetuses that were concomitantly infected by H. somni. Phylogenetic analysis revealed that the strain herein identified has 100% nucleotide (nt) sequence identity with wild type strains of BoGHV6 circulating in ruminants from Brazil and 99.8% nt identity with the reference strain of BoGHV6 but was 72.2-73.3% and 67.4-68.2% different from members of the MCFV group and PLHV, respectively. These results demonstrated that 76.9% of the fetuses evaluated were infected by BoGHV6, most likely via vertical infection resulting in transplacental transmission. Considering that most fetuses were concomitantly infected by BoGHV6 and H. somni the real impact of this viral infection cannot be efficiently determined. However, since BoGHV6 was the only pathogen identified in the myocardium of one fetus with myocarditis by histopathology, the possible participation of this Macavirus in the etiopathogenesis of the myocardial disease observed in this fetus cannot be ignored or discarded. However, the mere amplification of BoGHV6 DNA from the myocardium is not enough to establish a definite association between cause and effect, since in situ evaluations and experimental studies would be needed to confirm this agent in the etiopathogenesis of fetal diseases and/or abortions in cattle. Consequently, additional studies are needed to determine the exact role, if any, of BoGHV6 in the development of fetal disease, and possibly fetal mortality.

Sheep-associated malignant catarrhal fever (SA-MCF) is a severe, frequently fatal, lymphoproliferative disease that affects a wide variety of ruminants and is caused by ovine gammaherpesvirus 2 (OvHV-2), a member of the MCF virus (MCFV) complex. The typical clinical manifestations of SA-MCF are well known and easily recognized by veterinarians, resulting in clinical diagnosis of MCF when characteristic clinical signs are present. This article describes the findings observed in cattle infected with OvHV-2 but without typical clinical manifestations of SA-MCF. Three calves with episodes of diarrhea before death and a yearling that died suddenly were investigated. Gross alterations were not suggestive of SA-MCF. Histopathology revealed a combination of proliferating vascular lesions (PVLs) and necrotizing vasculitis in three animals (two calves and the yearling); with PVLs being identified only at the carotid rete mirabile of two calves infected with OvHV-2. Additional significant histopathologic lesions included atrophic enteritis, portal lymphocytic hepatitis, interstitial pneumonia, suppurative bacterial bronchopneumonia, and pulmonary hemorrhage. An immunohistochemical assay designed to identify only antigens of MCFV revealed, positive, intralesional, intracytoplasmic immunoreactivity within epithelial cells of multiple tissues of all animals with PVLs. PCR assays amplified OvHV-2 DNA from multiple tissues of the animals that contained MCFV proteins, confirming the MCFV identified as OvHV-2. Additionally, bovine coronavirus (BCoV) nucleic acids were amplified from tissues of all animals, including the animal not infected by OvHV-2. Collectively, these findings confirmed the participation of OvHV-2 in the development of the disease patterns observed in these animals that were concomitantly infected by BCoV and provide additional confirmation that cattle can be subclinically infected with OvHV-2. Consequently, the real occurrence of OvHV-2-related disease may be more elevated than reported, since asymptomatic or subclinically infected animals are not likely to be investigated for OvHV-2. Furthermore, PVLs should be included as possible histologic indicators of OvHV-2-related diseases in ruminants. Supplementary Information The online version contains supplementary material available at 10.1007/s42770-021-00653-6.

Equid gammaherpesvirus 2 (EHV-2) and 5 (EHV-5) are members of the Herpesviridae family and have been reported in horse populations worldwide. This study aimed to evaluate the presence of herpesvirus DNA in the upper respiratory tract of horses. Twenty-six nasal swabs were collected from asymptomatic adult horses of two different horse farms (A, n = 18; B, n = 8), both located in Southern Brazil. The EHV-1, EHV-2, EHV-4, and EHV-5 DNA analyses were performed using nested PCR assays targeting the glycoprotein B gene. Four (15.3%) and 12 (46.1%) of the 26 nasal swab samples were positive for the EHV-2 and EHV-5, respectively. Four (15.3%) horses were detected with both viruses simultaneously. DNA of EHV-2 and EHV-5 in both single and mixed infections was identified in horses from both herds. All swab samples were negative for EHV-1 and EHV-4. This study reports the first detection of EHV-2 and EHV-5 in the upper respiratory tracts of horses in Brazil. The high detection rate of EHV-2 and EHV-5 in asymptomatic adult horses demonstrates that these gammaherpesviruses are circulating in Brazil.

This study describes the etiological diversity observed in a severe neonatal diarrhea outbreak with morbidity and mortality rates of 80 and 20%, respectively, with detection of mixed infections with viral, bacterial, and protozoan disease agents in a dairy calf rearing unit. Diarrheic fecal samples were collected from eight 5 to 18 days of age calves and were submitted to the investigation of the presence of rotavirus A (RVA), bovine coronavirus (BCoV), bovine kobuvirus (BKV), bovine viral diarrhea virus 1 and 2 (BVDV-1 and BVDV-2), enteropathogenic Escherichia coli (ETEC), Salmonella sp., and Cryptosporidium spp. Fragments of the small intestine of one calf with diarrhea that spontaneously died were submitted for histopathological analyses. The most frequent infectious agent detected in diarrheic fecal samples was BKV (8/8—100%), followed by RVA (5/8—62.5%), BVDV (5/8—62.5%), Cryptosporidium parvum (5/8—62.5%), ETEC (4/8—50%), and Cryptosporidium ryanae (1/8—12.5%). These etiological agents were found in mixed infections with two or more pathogens per diarrheic fecal sample. The association of viral and protozoan pathogens was the most frequently identified (37.5%) in these samples, followed by viral and bacterial (25%); viral, bacterial, and protozoan (25%); and only viral agents (12.5%). BCoV and Salmonella sp. were not identified in the diarrheic fecal samples analyzed. Additionally, histopathology of the small intestine diagnosed chronic lymphocytic enteritis. In conclusion, in calf rearing units, the adoption and strict monitoring of health management practices are critical to the success of this calf creation system. Supplementary Information The online version contains supplementary material available at 10.1007/s42770-021-00565-5.

Bovine viral diarrhea virus (BVDV) is a major pathogen in cattle herds. Considering the epidemiological importance of pestiviruses and the process of wild boar invasion in Brazil, this study aimed to investigate the presence of BVDV in free-living boars. Forty-nine free-living wild boars were collected by exotic wildlife controller agents in 2017 and 2018. The presence of BVDV antibodies was evaluated in 42 serum samples using the virus neutralization test, and the detection of BVDV RNA was performed from the 5′UTR genomic region by RT-PCR assay in 49 lung tissue samples followed by sequencing of amplicons. BVDV neutralizing antibodies in serum were not identified in any of the evaluated samples. However, 3/49 (6.12%) lung samples were positive for BVDV RNA and classified one as BVDV-1a and two as 1d subgenotype. This report identified BVDV RNA in free-living wild boars and these results should be considered in BVDV control programs, especially in extensive beef cattle rearing systems.

BACKGROUND Suid gammaherpesvirus 3, 4, and 5 (porcine lymphotropic herpesvirus - PLHV-1, -2, and -3) are viruses that infect domestic and feral pigs. OBJECTIVES This study examined the presence of PLHV DNA in biological samples from free-living wild boars circulating in a Brazilian geographical region with a high density of commercial domestic pigs. METHODS Lung samples of 50 free-living wild boars were collected by exotic wildlife controller agents between 2017 and 2019 in the state of Parana, southern Brazil. Lung and spleen fragments were obtained from six fetuses collected by hysterectomy post mortem from a pregnant sow. A polymerase chain reaction (PCR) assay using consensus primers (pan-herpesviruses) was performed to detect PLHV DNA. The samples showing positive results for PLHV DNA were submitted to single-round PCR assays with the specific primers for identifying PLHV-1 (213-S/215-As), PLHV-2 (208-S/212-As), and PLHV-3 (886s/886As). The specificity of the species-specific PCR products was assessed by nucleotide sequencing of the amplicons. RESULTS Forty-eight (96%) of the 50 lung samples analyzed were positive for PLHV by PCR using pan-herpesvirus primers. In 33 (68.75%) of the positive samples, at least two PLHV species were identified simultaneously. The DNA of PLHV-1, -2, and -3 was found in free-living wild boars of all ages, but not in the fetuses, even though they were from a sow that tested positive for all three viruses. CONCLUSION These viruses are endemic to the population of feral pigs in the Brazilian region evaluated, as well as in domesticated pigs.

The atypical porcine pestivirus (APPV) belongs to the species Pestivirus K of the genus Pestivirus and the family Flaviviridae, and it has been associated with congenital tremor (CT) type A-II in newborn piglets. Although APPV was discovered in 2015, evidence shows that APPV has circulated in pig herds for many years, at least since 1986. Due to the frequently reported outbreaks of CT on different continents, the importance of this virus for global pig production is notable. Since 2015, several studies have been conducted to clarify the association between APPV and CT. However, some findings regarding APPV infection and the measures taken to control and prevent the spread of this virus need to be contextualized to understand the infection better. This review attempts to highlight advances in the understanding of APPV associated with type A-II CT, such as etiology, epidemiology, diagnosis, and control and prevention measures, and also describes the pathophysiology of the infection and its consequences for pig production. Further research still needs to be conducted to elucidate the host’s immune response to APPV infection, the control and prevention of this infection, and the possible development of vaccines.

We investigated the porcine lymphotropic herpesvirus (PLHV) DNA presence in multiple organs of pigs. Biological samples (n = 136) included tissue fragments of the central nervous system, heart, kidney, liver, lungs, spleen, urinary bladder, and urine. Sixty-eight (50%) organs were PLHV DNA-positive. None of the urine samples were detected with the virus genome. Although the presence of the PLHV DNA in the urinary bladder and kidney has been detected, it was not possible to show whether urine can be considered an effective route of virus shedding. This study warns to the risk of PLHV zoonotic transmission by xenotransplantation of tissues of porcine origin. ELECTRONIC SUPPLEMENTARY MATERIAL: The online version of this article (10.1007/s42770-020-00335-9) contains supplementary material, which is available to authorized users.

Highlights • BALF is a good biological sample for the molecular diagnosis of BRD in dairy calves. • Mixed infections of viruses and bacteria were frequent in dairy calves with respiratory disease. • BVDV 1d in BALF samples of dairy heifer calves in a BRD outbreak was characterized. • The calf rearing unit without prophylactic measures for respiratory infections represent a risk factor for BRD., The etiological agents involved in a bovine respiratory disease (BRD) outbreak were investigated in a dairy heifer calf rearing unit from southern Brazil. A battery of PCR assays was performed to detect the most common viruses and bacteria associated with BRD, such as bovine viral diarrhea virus (BVDV), bovine respiratory syncytial virus (BRSV), bovine alphaherpesvirus 1 (BoHV-1), bovine coronavirus (BCoV), bovine parainfluenza virus 3 (BPIV-3), Mannheimia haemolytica, Pasteurella multocida, Histophilus somni, and Mycoplasma bovis. Bronchoalveolar lavage fluid (BALF) samples were taken from 21 heifer calves (symptomatic n = 15; asymptomatic n = 6) that, during the occurrence of the BDR outbreak, were aged between 6 and 90 days. At least one microorganism was detected in 85.7% (18/21) of the BALF samples. Mixed infections were more frequent (72.2%) than single infections (27.7%). The interactions between viruses and bacteria were the most common in coinfections (55.5%). The frequencies of BRD agents were 38.1% for BRSV, 28.6% for BVDV, 33.3% for BCoV, 42.85% for P. multocida, 33.3% for M. bovis, and 19% for H. somni. BoHV-1, BPIV-3, and M. haemolytica were not identified in any of the 21 BALF samples. Considering that BALF and not nasal swabs were analyzed, these results demonstrate the etiological multiplicity that may be involved in BRD outbreaks in dairy calves.

Background: Bovine orthopneumovirus, formerly known as bovine respiratory syncytial virus (BRSV), is frequently associated with bovine respiratory disease (BRD). Aim: To perform the molecular characterization of the G and F proteins of Brazilian wild-type BRSV strains derived from bovine respiratory infections in both beef and dairy cattle. Materials and Methods: Ten BRSV strains derived from a dairy heifer rearing unit (n = 3) in 2011 and steers of three other feedlots (n = 7) in 2014 and 2015 were analyzed. For the BRSV G and F partial gene amplifications, RT-nested-PCR assays were performed with sequencing in both directions with forward and reverse primers used. Results: The G gene-based analysis revealed that two strains were highly similar to the BRSV sequences representative of subgroup III, including the Bayovac vaccine strain. However, the remaining seven Brazilian BRSV strains were diverse when compared with strains representative of the BRSV I to VIII subgroups. The central hydrophobic region of the Brazilian BRSV G gene showed the replacement of conserved cysteines and other residues of importance to antibody reactivity. The deduced F gene amino acid sequences from the Brazilian BRSV strains showed changes that were absent in the representative sequences of the known subgroups. Viral isolation on the nasopharyngeal swab suspensions failed to isolate BRSV. Conclusion: Results suggest that these strains represent a putative new subgroup of BRSV with mutations observed in the immunodominant region of the G protein. However, further studies on these Brazilian BRSV strains should be performed to establish their pathogenic potential.

In this study, we determined the distribution of senecavirus A (SVA) and viral RNA load in different organs and tissues of naturally infected piglets. A TaqMan-based qRT-PCR assay was performed using RNA extracted from brainstem, cerebellum, cerebrum, heart, kidney, liver, lungs, small intestine, spleen, urinary bladder, and tonsils of seven newborn piglets. SVA was detected in 57 out of 70 tissue samples (81.4%). Viral loads ranged from 4.07 to 10.38 log10 genomic copies per g of tissue. The results show that SVA has tropism for various organs in naturally infected newborn piglets, especially for tonsils, spleen, lungs, and liver. Lymphoid organs had the highest viral loads and may be important sites for SVA replication.

We investigated Seneca Valley virus (SVV) contamination in pig feed and feed ingredients. Twenty-seven samples were collected from two Brazilian feed mills and subjected to conventional RT-nested-PCR and qRT-PCR assays. Seven samples were SVV-positive with viral loads of 3.94-4.33 log10 genomic copies/g of feed. The study reveals SVV feed and feed ingredient contamination under natural conditions in Brazil.

Senecavirus A (SVA) é a única espécie do gênero Senecavirus, família Picornaviridae. SVA é um vírus RNA fita simples, de polaridade positiva, não envelopado e genoma com aproximadamente 7,2 kb. Desde 2007, SVA tem sido associado à doença vesicular em suínos nos Estados Unidos da América, Brasil, Colômbia, China e Tailândia. A partir de 2015, uma nova síndrome multissistêmica associada à infecção por SVA tem sido relatada em leitões recém-nascidos nesses países. SVA foi identificado por técnicas moleculares (RT-PCR, qRT-PCR e nested-RT-PCR), imuno-histoquímica e/ou hibridização in situ em diferentes órgãos de leitões recém-nascidos. Embora a RT-PCR quantitativa (qRT-PCR) tenha sido utilizada para detectar RNA de SVA a partir de amostras biológicas de suínos, não há relatos da determinação da carga viral nos diferentes tecidos de leitões recém-nascidos com sinais clínicos consistentes com a infecção pelo vírus. O objetivo deste estudo foi avaliar a distribuição tecidual e a carga viral de SVA em diferentes amostras biológicas de leitões sintomáticos, naturalmente infectados, provenientes de rebanhos suínos com histórico de doença vesicular. No primeiro estudo foi validado um teste de qRT-PCR utilizando TaqMan como ferramenta para a detecção e quantificação de RNA de SVA em amostras biológicas de suínos. Um conjunto de primers e probe específicos para amplificar um produto de 118 pb da região VP1 do genoma do vírus foi desenhado para ser utilizado na técnica de qRT-PCR. A avaliação da eficiência da qRT-PCR TaqMan foi realizada em 45 amostras de tecidos de 15 leitões sintomáticos (n = 38) e quatro (n = 7) assintomáticos previamente caracterizados como positivos ou negativos para SVA por RT-PCR convencional. Entre amostras biológicas provenientes de leitões sintomáticos, 18 (47,4%) e 30 (78,9%) foram positivas por RT-PCR convencional e qRT-PCR, respectivamente. Todas as amostras obtidas de leitões assintomáticos foram negativas para o vírus em ambas as técnicas utilizado. Os resultados demonstram que a técnica de qRT-PCR utilizando TaqMan padronizada neste estudo é rápida e apresenta alta sensibilidade, especificidade e repetibilidade, sendo capaz de gerar resultados confiáveis na detecção e quantificação de RNA de SVA em amostras biológicas de suínos. O segundo estudo avaliou a distribuição e a carga viral de SVA em diferentes amostras de órgãos/tecidos provenientes de leitões recém-nascidos sintomáticos. Por meio da técnica qRT-PCR previamente padronizada no primeiro estudo, foram analisados fragmentos de tronco encefálico, cerebelo, cérebro, coração, rim, fígado, pulmões, intestino delgado, baço, bexiga e tonsila provenientes de sete leitões recém-nascidos. O RNA de SVA foi detectado em 81,4% (57/70) das amostras avaliadas. A carga viral variou de 4,07 a 10,38 log10 cópias genômicas/g de tecido. Os resultados demonstram que o SVA tem tropismo por diferentes órgãos em leitões recém-nascidos naturalmente infectados, principalmente tonsilas, baço, pulmão e fígado. Órgãos linfoides apresentam altas cargas virais e podem ser importantes sítios de replicação de SVA. A ampla distribuição de RNA de SVA em órgãos/tecidos dos sistemas cardiovascular, respiratório, digestório, urinário, neurológico e linfático demonstra a capacidade do vírus em causar infecção multissistêmica em leitões recém-nascidos e a sua participação nas manifestações clínicas observadas. Senecavirus A (SVA) is the only member of the Senecavirus genus, Picornaviridae family. SVA is a single-stranded, positive-sense, non-enveloped RNA virus with a genome size of approximately 7.2 kb. Since 2007 reports have revealed SVA-associated vesicular disease in pigs in the USA, Brazil, China, Colômbia, and Thailand. From 2015, a novel multisystemic syndrome associated with SVA infection has been reported in newborn piglets from these countries. SVA was detected by techniques such as molecular (RT-PCR, qRT-PCR and nested-RT-PCR), immunohistochemical, and/or in situ hybridization assays in different organs/tissues of newborn piglets. Although quantitative RT-PCR (qRT-PCR) assays have been used to detect the SVA genome from organ samples of piglets, there are no reports of the SVA RNA loads in tissues of newborn piglets with clinical signs consistent with SVA infection. The aim of this study was evaluate the SVA distribution and RNA loads in different biological samples of naturally infected symptomatic piglets originating from vesicular disease-affected pig herds. In the first study a TaqMan-based qRT-PCR assay was validated for SVA RNA detection and quantification in biological porcine specimens. A set of specific primers and probe was designed to amplify a 118 bp length fragment within the VP1 gene of the SVA genome. The efficiency of TaqMan-based qRT-PCR was evaluated in 45 tissue samples of 15 symptomatic (n = 38) and 4 (n = 7) asymptomatic piglets, previously caracterized as positive or negative for SVA by conventional RT-PCR. Among the biological samples of symptomatic piglets, 18 (47.4%) and 30 (78.9%) were positive for SVA in conventional RT-PCR and qRT-PCR assays, respectively. All samples obtained from asymptomatic piglets were negative for the virus in both assays. The results demonstrated that the TaqMan-based qRT-PCR assay in this study is a rapid technique with high sensitivity, specificity and reproducibility, able to generate reliable results to simultaneously detect and quantify SVA RNA in porcine biological samples. The second study determined the SVA RNA distribution and loads in different organs/tissues from symptomatic newborn piglets. Using the qRT-PCR assay previously developed in the first study, fragments of brainstem, cerebellum, cerebrum, heart, kidney, liver, lungs, small intestine, spleen, urinary bladder, and tonsils of seven newborn piglets were analyzed. SVA was detected in 81.4% (57/70) of the tissue samples. Viral loads ranged from 4.07 to 10.38 log10 genomic copies/g of tissue. The results show that SVA has tropism for different organs in naturally infected newborn piglets, mainly tonsils, spleen, lungs, and liver. Lymphoid organs contained the highest viral loads and may be important sites for SVA replication. The wide SVA RNA distribution in organs/tissues of the cardiovascular, repiratory, digestive, urinary, neurological, and lymphatic systems demonstrate the virus ability to cause multisystemic infection in newborn piglets and the participation of SVA in the observed clinical manifestations.

Senecavirus A (SVA) has been associated with vesicular disease in weaned and adult pigs and with high mortality of newborn piglets. This study aimed to establish a nested-PCR assay for the routine diagnosis of SVA infection. Tissue samples (n = 177) were collected from 37 piglets of 18 pig farms located in four different Brazilian states. For the nested-PCR, a primer set was defined to amplify an internal VP1 fragment of 316 bp of SVA genome. Of the 37 piglets, 15 (40.5%) and 23 (62.2%) were positive for the SVA in the RT-PCR and nested-PCR assays, respectively. The SVA RNA was detected in 61/177 (34.5%) samples with the RT-PCR, while the nested-PCR assay showed 84/177 (47.5%) samples with the virus (p

This study describes a sensitive (1.3 × 101 genomic copies/μL) and specific TaqMan-based qRT-PCR assay able to detect and quantify SVA RNA in porcine biological samples. The technique represents an efficient tool for the virus diagnosis and assessment of SVA load in tissues of infected animals and for epidemiological studies.

In order to understand better the pathological aspects and spread of Pasteurella multocida type A as the primary cause of pneumonia in pigs, was made an experiment with intranasal inoculation of different concentrations of inocula [Group (G1): 108 Colony Forming Units (CFU)/ml; G2: 107 CFU/ml; G3: 106 CFU/ml and G4: 105 CFU/ml], using two pigs per group. The pigs were obtained from a high health status herd. Pigs were monitored clinically for 4 days and subsequently necropsied. All pigs had clinical signs and lesions associated with respiratory disease. Dyspnoea and hyperthermia were the main clinical signs observed. Suppurative cranioventral bronchopneumonia, in some cases associated with necrosuppurative pleuropneumonia, fibrinous pericarditis and pleuritic, were the most frequent types of lesion found. The disease evolved with septicaemia, characterized by septic infarctions in the liver and spleen, with the detection of P. multocida type A. In this study, P. multocida type A strain #11246 was the primary agent of fibrinous pleuritis and suppurative cranioventral bronchopneumonia, pericarditis and septicaemia in the pigs. All concentrations of inoculum used (105-108 CFU/ml) were able to produce clinical and pathological changes of pneumonia, pleuritis, pericarditis and septicemia in challenged animals. Resumo: Para entender melhor os aspectos patológicos e disseminação de Pasteurella multocida tipo A como causa primária de pneumonia em suínos foi realizado um experimento com inoculação intranasal de diferentes concentrações de inóculos [Grupo (G1): 108 Unidades Formadoras de Colônias (UFC)/ml; G2: 107 UFC/ml; G3: 106 UFC/ml e G4: 105 UFC/ml], usando dois suínos por grupo. Esses suínos foram obtidos de um rebanho de alto status sanitário. Os animais foram monitorados clinicamente por quarto dias e subsequentemente necropsiados. Todos os suínos apresentaram sinais clínicos e lesões associadas com doença respiratória. Dispneia e hipertermia foram os principais sinais clínicos observados. Broncopneumonia cranioventral supurativa, em alguns casos associados com pleuropneumonia necrossupurativa, pleurites e pericardite fibrinosa foram mais frequentes. A doença evoluiu com septicemia, caracterizada por infartos sépticos no fígado e baço, com detecção de P. multocida. Neste estudo, P. multocida tipo A isolado 11246 foi agente primário de pleurite fibrinosa e broncopneumonia cranioventral supurativa, pericardite fibrinosa e septicemia em suínos. Todas as concentrações de inóculo utilizado (105-108 UFC/ml) foram capazes de produzir sinais clínicos e patológicos de alterações de pneumonia, pleurites, pericardites e septicemia nos animais.

Circovírus suíno 3 (PCV-3) é um vírus emergente na produção de suínos e Mycoplasma hyopneumoniae (Mhyo) é considerado um dos patógenos respiratórios mais importantes na suinocultura mundial. Em todo o mundo há poucos trabalhos que avaliam a prevalência destes microrganismos em suínos asselvajados. Considerando as diferentes classes e características dos microrganimos avaliados, serão apresentados dois estudos: o primeiro aborda a investigação sobre a infecção por PCV-3 em suínos asselvajados de vida livre e o segundo sobre a infecção por Mhyo na mesma amostragem. Os animais foram manejados por controladores autorizados, entre 2017 e 2019 no estado do Paraná, Brasil, e georreferenciamento, sexo e peso foram registrados para cada animal. No primeiro estudo, amplicons com tamanho de 330 pb foram obtidos por PCR convencional em 7/70 (10,0%) amostras de soro avaliadas e confirmados específicos para PCV-3 por análise da sequência de nucleotídeos (nt). Em seguida, amostras de pulmão provenientes dos sete animais previamente positivos no soro foram também avaliadas por PCR. Destas, três amostras apresentaram boa quantificação de DNA e foram submetidas ao sequenciamento genômico completo para análise filogenética das cepas de PCV-3 identificadas. As três sequências completas obtidas foram agrupadas no clado “a” de PCV-3 e as sequências apresentaram 100% de identidade de nt entre si. As cepas de PCV-3 deste estudo possuem 99,5% a 99,8% e 98,8% a 100% de identidade de nt e similaridade de aminoácido (aa), respectivamente, com as sequências de genoma completo de cepas de todo o mundo. No segundo estudo, a presença de anticorpos anti-Mhyo foi avaliada por meio de kit comercial de ELISA indireto em 88 amostras de soro. Adicionalmente, a presença de lesões macroscópicas semelhantes à pneumonia enzoótica foi identificada em 27 amostras de pulmões, e a marcação pela técnica de imuno-histoquímica (IHQ) foi observada em 15/27 (55,5%) amostras. O teste do qui-quadrado e a intensidade da associação com o odds ratio e intervalo de confiança de 95% foram utilizados para avaliar as diferenças nas variáveis qualitativas entre os grupos (sexo e município). Os javalis jovens apresentaram maior seroprevalência para Mhyo do que os mais velhos (p=0,005). O município de Teixeira Soares diferiu na taxa de soroprevalência de Mhyo comparado aos municípios de Castro (p