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1.
Vet Microbiol ; 235: 101-109, 2019 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-31282367

RESUMO

Highly virulent porcine reproductive and respiratory syndrome virus (PRRSV) strains have increasingly overwhelmed Asia and Europe in recent years. This study aims to compare the clinical signs, gross and microscopic findings as well as the expression of CD163 within live pulmonary alveolar macrophages (PAMs) from bronchoalveolar lavage fluid (BALF) of pigs experimentally infected with two PRRSV strains of different virulence. Pigs were infected with either a subtype 1 PRRSV-1 3249 strain or a subtype 3 PRRSV-1 Lena strain and consecutively euthanized at 1, 3, 6, 8 and 13 days post-inoculation. Clinical signs were reported daily and BALF and lung tissue samples were collected at the different time-points and accordingly processed for their analysis. Pigs infected with Lena strain exhibited greater clinical signs as well as gross and microscopic lung scores compared to 3249-infected pigs. A decreased frequency of PAMs from BALF was observed early in pigs infected with Lena strain. Moreover, the frequency and median fluorescence intensity (MFI) of CD163 within PAMs were much lower in Lena-infected pigs than in 3249-infected pigs. This downregulation in CD163 was also observed in lung sections after the assessment of macrophages expressing CD163 by means of immunohistochemistry. This outcome may result from the effect of PRRSV replication, PRRSV-induced inflammation, the influx of immature macrophages to restore lung homeostasis and/or the evidence of CD163low cells after CD163+ cells decrease in BALF.


Assuntos
Antígenos CD/genética , Antígenos de Diferenciação Mielomonocítica/genética , Broncopneumonia/veterinária , Macrófagos Alveolares/imunologia , Síndrome Respiratória e Reprodutiva Suína/imunologia , Vírus da Síndrome Respiratória e Reprodutiva Suína/patogenicidade , Receptores de Superfície Celular/genética , Animais , Antígenos CD/imunologia , Antígenos de Diferenciação Mielomonocítica/imunologia , Líquido da Lavagem Broncoalveolar/citologia , Broncopneumonia/virologia , Regulação para Baixo , Feminino , Pulmão/citologia , Pulmão/virologia , Macrófagos Alveolares/virologia , Masculino , Vírus da Síndrome Respiratória e Reprodutiva Suína/imunologia , Receptores de Superfície Celular/imunologia , Suínos , Virulência
2.
Vet Microbiol ; 234: 34-43, 2019 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-31213270

RESUMO

Mannheimia haemolytica is an important cause of bovine respiratory disease (BRD). BRD is usually a multifactorial disease with host factors and viral infections influencing pathogenesis. Previous studies that have attempted to experimentally induce pneumonia using aerosolized M. haemolytica alone have produced inconsistent results, yet an aerosol model would be useful to study the details of early infection and to investigate the role of innate defences in pathogenesis. The objective of these studies was to develop and characterize an aerosolized M. haemolytica disease model. In an initial study, conventionally raised calves with higher levels of antibody against M. haemolytica leukotoxin developed acute respiratory distress and diffuse alveolar damage, but did not develop bronchopneumonia, following challenge with M. haemolytica serotype 1. Clean-catch colostrum-deprived calves challenged with 1 × 1010 colony forming units of M. haemolytica serotype 1 consistently developed bronchopneumonia, with elevations in rectal temperature, serum haptoglobin, plasma fibrinogen, and blood neutrophils. Mannheimia haemolytica serotype 1 was consistently isolated from the nasal cavities and lungs of challenged calves. Despite distribution of aerosol and isolation of M. haemolytica in all lung lobes, gross lesions were mainly observed in the cranioventral area of lung. Gross and histologic lesions included neutrophilic bronchopneumonia and fibrinous pleuritis, with oat cells (necrotic neutrophils with streaming nuclei), and areas of coagulative necrosis, which are similar to lesions in naturally occurring BRD. Thus, challenge with M. haemolytica serotype 1 and use of clean-catch colostrum-deprived calves with low or absent antibody titres allowed development of an effective aerosol challenge model that induced typical clinical disease and lesions.


Assuntos
Broncopneumonia/veterinária , Colostro , Modelos Animais de Doenças , Mannheimia haemolytica/patogenicidade , Pneumonia Bacteriana/veterinária , Aerossóis , Fatores Etários , Animais , Broncopneumonia/microbiologia , Bovinos , Doenças dos Bovinos/microbiologia , Feminino , Fibrinogênio/análise , Haptoglobinas/análise , Pulmão/microbiologia , Pulmão/patologia , Neutrófilos/microbiologia , Neutrófilos/patologia , Alvéolos Pulmonares/microbiologia , Alvéolos Pulmonares/patologia
3.
J Vet Diagn Invest ; 31(5): 674-680, 2019 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-31246162

RESUMO

Viral agents such as bovine respiratory syncytial virus (BRSV) and bovine parainfluenza virus 3 (BPIV-3) are considered primary infectious agents in bovine respiratory disease complex (BRDC). Information regarding the pathogenesis of BRDC is scarce, especially at an advanced chronicity stage, in addition to ongoing coinfection with other primary agents such as Mycoplasma bovis. Based on a retrospective review of histology slides from 104 autopsy cases, we classified cases according to type of pneumonia and chronicity. We performed immunohistochemistry (IHC) for BRSV, BPIV-3, and M. bovis as well as real-time PCR (rtPCR) for M. bovis on lung tissue of all 104 cases and correlated results with the morphologic type of pneumonia. Histomorphologically, 79 cases were classified as bronchopneumonia, 16 as bronchointerstitial pneumonia, and 9 as interstitial pneumonia. In 89 cases, at least 1 of the investigated agents was detected by IHC; 44 of these cases had a coinfection. BPIV-3 was the predominant agent present, as a single infection in 39 cases, and in coinfection with M. bovis in 39 cases. Comparing the detection methods for M. bovis, rtPCR was more specific and sensitive than IHC. The combination of both methods provided a good visual tool for assessing severity and distribution of M. bovis antigen within the tissue. Unlike BRSV, BPIV-3 and M. bovis persisted in chronic BRDC, suggesting ongoing impairment of defense mechanisms in the lung.


Assuntos
Complexo Respiratório Bovino , Infecções por Mycoplasma/veterinária , Mycoplasma bovis , Vírus da Parainfluenza 3 Bovina , Infecções por Vírus Respiratório Sincicial/veterinária , Vírus Sincicial Respiratório Bovino , Infecções por Respirovirus/veterinária , Doença Aguda , Animais , Broncopneumonia/veterinária , Bovinos , Doenças dos Bovinos/diagnóstico , Doenças dos Bovinos/microbiologia , Doenças dos Bovinos/virologia , Doença Crônica/veterinária , Coinfecção , Estudos Retrospectivos
4.
J Vet Med Sci ; 81(7): 1043-1046, 2019 Jul 19.
Artigo em Inglês | MEDLINE | ID: mdl-31189765

RESUMO

The aim of this study was to investigate the relationship between the endotoxin activity in plasma and that in bronchoalveolar lavage fluid (BALF) in bronchopneumonia. Thirty-three calves were included in this study (17 healthy calves and 16 calves with respiratory disease). In the calves with bronchopneumonia, the median endotoxin activity in plasma (0.437 EU/ml, P<0.001) and BALF (29.45 EU/ml, P<0.001) was significantly higher than in the control calves. Plasma endotoxin activity was significantly and positively correlated with that in BALF (r2=0.900, P<0.001). Based on the receiver operating characteristics curves, we propose a diagnostic cutoff point for plasma endotoxin activity (0.104 EU/ml, AUC=0.914, P<0.001, Se 81.3% and Sp 82.4%) for identification of bronchopneumonia in calves which could die within a week.


Assuntos
Líquido da Lavagem Broncoalveolar/química , Broncopneumonia/veterinária , Doenças dos Bovinos/diagnóstico , Endotoxinas/análise , Endotoxinas/sangue , Animais , Broncopneumonia/diagnóstico , Estudos de Casos e Controles , Bovinos , Doenças dos Bovinos/sangue , Feminino , Masculino , Infecções por Mycoplasma/veterinária , Mycoplasma bovis/isolamento & purificação , Sensibilidade e Especificidade
5.
Vet Microbiol ; 231: 232-237, 2019 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-30955815

RESUMO

Pasteurella multocida is a heterogeneous bacterium, which has the capacity to cause disease in a wide range of host species and is also recognized as an important zoonotic pathogen. Two sequential deaths in captive fur seals occurred at Sea World, Australia during December 2017. A fibrinosuppurative bronchopneumonia in a Subantarctic fur seal (Arctocephalus tropicalis) resulted in death within 24 h of nonspecific signs of illness, whereas a septic peritonitis in a New Zealand fur seal (Arctocephalus forsteri) resulted in death within 12 h of clinical presentation. The cases happened within three days in two different pool locations, although both had previously been housed in the same area. A total of six Pasteurella multocida isolates were obtained from several internal organs at necropsy in both cases and were subjected to whole genome sequencing and phylogenomic analysis. In-silico typing of the isolates revealed that all belonged to Multi-Locus Sequence Type 7 and carried lipopolysaccharide outer core biosynthesis loci Type 3. Phylogenomic analysis of the isolates confirmed that the isolates were near identical at the core genome level, suggesting acquisition from a common source. The results also revealed the presence of within host and across animal diversity of P. multocida isolates for the first time even in a clearly connected outbreak.


Assuntos
Broncopneumonia/veterinária , Otárias/microbiologia , Infecções por Pasteurella/veterinária , Pasteurella multocida/genética , Peritonite/veterinária , Animais , Austrália , Aves/microbiologia , Broncopneumonia/microbiologia , Broncopneumonia/mortalidade , Variação Genética , Genoma Bacteriano , Nova Zelândia , Infecções por Pasteurella/transmissão , Pasteurella multocida/classificação , Peritonite/microbiologia , Peritonite/mortalidade , Filogenia , Sequenciamento Completo do Genoma
6.
J Comp Pathol ; 167: 41-45, 2019 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-30898296

RESUMO

Twenty-two newborn puppies that did not receive colostrum exhibited acute respiratory signs and died at a breeding facility. Pathological examinations were performed on four of the puppies. At necropsy examination, the lungs were firm and mottled dark red, consistent with acute bronchopneumonia. Histopathologically, there was marked infiltration of neutrophils and macrophages into the bronchi and alveoli, and gram-negative coccobacilli were attached diffusely to the cilia of bronchial mucosa. Immunohistochemistry for Bordetella bronchiseptica antigen revealed positive labelling of the bacterial agents. On electron microscopy, a large number of coccobacilli were observed attaching to the cilia of bronchial epithelial cells. Real-time polymerase chain reaction amplified a B. bronchiseptica gene from the affected lung tissue. Based on these findings, the four puppies were diagnosed with fatal B. bronchiseptica bronchopneumonia.


Assuntos
Infecções por Bordetella/veterinária , Broncopneumonia/veterinária , Doenças do Cão/patologia , Animais , Animais Recém-Nascidos , Bordetella bronchiseptica , Surtos de Doenças , Doenças do Cão/epidemiologia , Cães , Feminino , Masculino
7.
J Vet Intern Med ; 33(3): 1540-1546, 2019 May.
Artigo em Inglês | MEDLINE | ID: mdl-30901138

RESUMO

BACKGROUND: Severity of lung lesions quantified by thoracic ultrasonography (TUS) at time of bronchopneumonia (BP) diagnosis predicted death among steers not treated for this condition. Further research is needed to confirm that lung lesions detected by TUS can be associated with negative outcomes in cattle with BP that subsequently were treated. OBJECTIVE: To quantify the effects on relapse rate and average daily gain (ADG) of lung lesions detected by TUS at first BP diagnosis in feedlot cattle. ANIMALS: Prospective cohort of mixed beef-breed steers (n = 93; 243 ± 36 kg) and heifers (n = 51; 227 ± 42 kg) with BP at 4 feedlots. METHODS: Thoracic ultrasonography was performed by the same clinician and 16-second TUS videos were evaluated offline for maximal depth and area of lung consolidation, maximum number of comet tails, and maximal depth of pleural fluid. Individual ADG was calculated between 1 and 120 days after arrival. Effects of lesions on relapse rate and ADG were investigated using mixed regression models. RESULTS: Maximal depth of lung consolidation was associated with a higher risk of relapse (odds ratio [OR], 1.337/cm; 95% confidence interval [CI], 1.042-1.714) and lower ADG (- 34 g/cm; -64 to -4). Maximal area of lung consolidation also was associated with a higher relapse risk (OR, 1.052/cm2 ; 1.009-1.097) but not with ADG. Comet tails and pleural fluid were not associated with risk of relapse or ADG. CONCLUSIONS AND CLINICAL IMPORTANCE: Quantifying maximal depth and area of lung consolidation by TUS at first BP diagnosis can provide useful prognostic information in feedlot cattle.


Assuntos
Broncopneumonia/veterinária , Doenças dos Bovinos/diagnóstico por imagem , Bovinos/crescimento & desenvolvimento , Ultrassonografia/veterinária , Animais , Broncopneumonia/diagnóstico por imagem , Broncopneumonia/patologia , Doenças dos Bovinos/patologia , Estudos de Coortes , Feminino , Pulmão/patologia , Masculino , Estudos Prospectivos , Recidiva
8.
Acta Parasitol ; 64(2): 411-417, 2019 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-30756237

RESUMO

AIMS: Aelurostrongylus abstrusus (Railliet, 1898) and Angiostrongylus chabaudi (Biocca, 1957) are important cardiopulmonary metastrongyloids in felids. This case report describes, for the first time, a natural and patent mixed infection caused by A. abstrusus and A. chabaudi in a European wildcat (Felis silvestris silvestris) from Bosnia and Herzegovina. Most important, this is a rare report of fatal parasitism in wildlife, involving a severe verminous bronchopneumonia and gastrointestinal nematode and cestode infection with Toxocara cati, Taenia taeniaeformis, Aonchotheca putorii, and Ancylostoma spp. RESULTS: Emphasis is set to detailed description of granulomatous, interstitial verminous bronchopneumonia, morphological description of A. abstrusus and A. chabaudi, and molecular confirmation of diagnosis by triplex PCR. CONCLUSION: The data provided in this study contribute to the knowledge on the epizootiology and pathological effect of these neglected metastrongyloids in European wildcat.


Assuntos
Broncopneumonia/veterinária , Coinfecção/parasitologia , Felis/parasitologia , Infecções por Strongylida/veterinária , Animais , Península Balcânica , Bósnia e Herzegóvina , Broncopneumonia/diagnóstico , Broncopneumonia/parasitologia , Evolução Fatal , Fezes/parasitologia , Feminino , Pulmão/parasitologia , Pulmão/patologia , Masculino , Metastrongyloidea/anatomia & histologia , Infecções por Strongylida/diagnóstico
10.
J Vet Diagn Invest ; 31(1): 103-106, 2019 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-30475680

RESUMO

Eleven adult African pygmy hedgehogs ( Atelerix albiventris) were added to a group of 35 animals, and within 10 d, respiratory distress affected 8 of 35 resident animals in the group, but none of the introduced animals. Three animals died following onset of clinical signs. Tissues from one animal were collected and submitted for histopathology, which revealed acute necrotizing bronchopneumonia and tracheitis with intraepithelial intranuclear inclusion bodies. Electron microscopy identified 75-90 nm diameter encapsulated icosahedral virions. Degenerate nested PCR analysis identified adenovirus within the affected lung tissue. Deep sequencing showed 100% homology to skunk adenovirus 1 (SkAdV-1). Adenoviruses are usually species-adapted and -specific, but our case supports the single previous report of non-skunk infection with SkAdV-1, indicating that this virus can infect other species, and further shows that it can cause fatal disease.


Assuntos
Infecções por Adenoviridae/veterinária , Broncopneumonia/veterinária , Ouriços-Cacheiros , Mastadenovirus/isolamento & purificação , Infecções por Adenoviridae/diagnóstico , Infecções por Adenoviridae/patologia , Infecções por Adenoviridae/virologia , Animais , Broncopneumonia/diagnóstico , Broncopneumonia/patologia , Broncopneumonia/virologia , Microscopia Eletrônica de Transmissão/veterinária , Reação em Cadeia da Polimerase
11.
Schweiz Arch Tierheilkd ; 160(12): 737-741, 2018 Dec.
Artigo em Alemão | MEDLINE | ID: mdl-30516476

RESUMO

INTRODUCTION: The goal of this study was to analyse the frequency of ultrasonographic findings in 129 calves with bronchopneumonia and to determine how often multiple abnormalities occur in individual calves. The frequency of abnormal ultrasonographic findings ranged from 4 to 88%. Comet-tail artifacts were the most common finding (88%) followed in decreasing order by scattered echogenic foci (69%), air bronchograms (44%), superficial alveolograms (29%), pleural effusion (26%), hepatisation (23%), pleural lesions (18%), fluid bronchograms (14%), lung abscesses (6%) and fibrin deposits or fibrin strands (4%). Thoracic ultrasonography yielded a mean of 3.3 ± 1.55 abnormal findings (range, 1-6) per calf. Ultrasonography of the lungs in calves with bronchopneumonia is a useful adjunct to clinical examination and allows the determination of the type and severity of lesions.


Assuntos
Broncopneumonia/veterinária , Doenças dos Bovinos/diagnóstico por imagem , Pulmão/diagnóstico por imagem , Animais , Broncopneumonia/diagnóstico por imagem , Broncopneumonia/patologia , Bovinos , Doenças dos Bovinos/patologia , Pulmão/patologia , Ultrassonografia/veterinária
13.
Vet Microbiol ; 225: 139-148, 2018 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-30322526

RESUMO

The composition of the nasopharyngeal bacterial microbiota has been shown to play a role in cattle respiratory health. However, previous studies are narrow in scope regarding longitudinal observations, limiting our understanding of how respiratory bacteria evolve over time. The objective was therefore to characterize this microbiota and its evolution over time in beef calves. A total of 120 crossbred beef-breed steer calves were enrolled in a study in southern Alberta at the time of first vaccination (spring processing), comprising three groups (40 calves/group) that originated from different ranches and were placed in different feedlots. Deep nasopharyngeal swab samples were collected from the calves at the time of spring processing, arrival at the feedlot, and a targeted 40 days after feedlot arrival. The swabs were processed for DNA extraction and the V4 region of the 16S rRNA gene was sequenced to evaluate the microbiota. The composition of the microbiota differed among groups of calves, with each group showing different relative abundances of 963 observed sequence variants. Mycoplasma was the most abundant genus and M. dispar the most abundant species across all groups. There was a distinct shift in the composition of the microbiota over time for all calf groups; however, changes in sequence variants differed by group. Variations in both microbiota composition and temporal changes of sequence variants according to calf group indicates that the respiratory microbiota of beef cattle may lack a common pattern of evolution from ranch to feedlot, and that future studies should account for potential group effects.


Assuntos
Bactérias/genética , Doenças dos Bovinos/epidemiologia , Evolução Molecular , Microbiota/genética , Nasofaringe/microbiologia , Fatores Etários , Animais , Bactérias/isolamento & purificação , Complexo Respiratório Bovino/microbiologia , Broncopneumonia/epidemiologia , Broncopneumonia/microbiologia , Broncopneumonia/veterinária , Bovinos/microbiologia , Doenças dos Bovinos/microbiologia , DNA Bacteriano/genética , Estudos Longitudinais , Mycoplasma/isolamento & purificação , Pasteurelose Pneumônica/epidemiologia , Pasteurelose Pneumônica/microbiologia , RNA Ribossômico 16S/genética , Carne Vermelha , Fatores de Tempo
14.
Acta Vet Scand ; 60(1): 54, 2018 Sep 17.
Artigo em Inglês | MEDLINE | ID: mdl-30223865

RESUMO

BACKGROUND: One of the most common post-mortem inspection finding of sheep and lambs in Sweden, following routine slaughter is pneumonia and its prevalence is increasing. To our knowledge, the aetiology of pneumonia in lambs is not well-known for Swedish conditions. Chronic bronchopneumonia, also known as "atypical" or chronic non-progressive pneumonia, is a common disease worldwide, affecting lambs up to 12 months old. It is therefore of interest to elucidate if this disease complex is also a common cause of pneumonia among Swedish lambs. Chronic bronchopneumonia has a characteristic macroscopic and histopathologic appearance, and Mycoplasma ovipneumoniae is the microbial agent most frequently found. Although this bacterium is important for the pathogenesis, multiple agents are presumed to be involved. The aim of this study was to describe the macroscopic and histopathologic lung lesions in routinely slaughtered lambs with pneumonia, and to determine the bacterial agents involved. RESULTS: A total of 41 lungs with gross lesions consistent with pneumonia were examined. Of these, 35 lungs displayed the typical gross appearance of chronic bronchopneumonia, with several or all of the characteristic histological features. M. ovipneumoniae was detected in 83% of the 35 lungs and Mannheimia haemolytica was isolated in 71%. Pneumonia associated with M. ovipneumoniae could be correlated to specific gross lesions consistent with the gross description of chronic bronchopneumonia in lambs. CONCLUSION: In this study, chronic bronchopneumonia was the most common lung disease in routinely slaughtered Swedish lambs. This diagnosis was based on the characteristic macroscopic and histopathologic pulmonary findings and the frequent presence of the bacterium M. ovipneumoniae. The macroscopic appearance of chronic bronchopneumonia could therefore be used during routine investigation of the lamb carcasses at slaughter, to determine the most likely cause of pneumonia.


Assuntos
Broncopneumonia/veterinária , Pulmão/microbiologia , Pulmão/patologia , Mannheimia haemolytica/fisiologia , Mycoplasma ovipneumoniae/fisiologia , Doenças dos Ovinos/microbiologia , Doenças dos Ovinos/patologia , Animais , Broncopneumonia/diagnóstico , Broncopneumonia/microbiologia , Broncopneumonia/patologia , Ovinos , Doenças dos Ovinos/diagnóstico , Suécia
15.
J Vet Intern Med ; 32(5): 1787-1792, 2018 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-30133838

RESUMO

BACKGROUND: Thoracic ultrasonography (TUS) can be used to assess the extent and severity of lung lesions associated with bronchopneumonia (BP) in feedlot cattle. HYPOTHESIS/OBJECTIVES: To assess inter-rater agreement and reliability of TUS findings in feedlot cattle, with or without naturally occurring BP. ANIMALS: Feedlot steers with (n = 210) or without (n = 107) clinical signs of BP that were assessed by TUS in a previous case-control study. METHODS: A random sample of 50 TUS videos (16-s duration) were scored by 6 raters with various levels of TUS expertise. Lung consolidation, comet tail artifacts, pleural irregularity and effusion were scored. Inter-rater agreement was assessed using raw percentage of agreement (Pa), Cohen's and Fleiss' Kappa (κ), and Gwet agreement coefficient (AC1). Intra-class correlation (ICC) was determined for variables with continuous measurements (mixed factorial design). RESULTS: Median (interquartile range [IQR]) Pa were 0.84 (0.80-0.89), 0.82 (0.80-0.87), 0.62 (0.53-0.67), and 0.82 (0.75-0.86) for presence of lung consolidation, comet tails, pleural irregularity, and pleural effusion, respectively. For the same lesions, Fleiss κ (95% confidence intervals [CI]) were 0.67 (0.49-0.86), 0.56 (0.33-0.80), 0.20 (-0.05 to 0.44), and 0.36 (0.10-0.61), respectively. AC1 were 0.68 (0.51-0.86), 0.73 (0.58-0.89), 0.21 (-0.01 to 0.44), and 0.71 (0.51-0.92), respectively. Moderate reliability was found among raters for all quantitative variables (ICC ranged from 0.52 to 0.70). CONCLUSIONS AND CLINICAL IMPORTANCE: Inter-rater agreement was good for presence of lung consolidation, comet tails and pleural effusion (based on Pa and AC1) but was slight to poor for pleural irregularity.


Assuntos
Broncopneumonia/veterinária , Doenças dos Bovinos/diagnóstico por imagem , Ultrassonografia/veterinária , Animais , Broncopneumonia/diagnóstico por imagem , Broncopneumonia/patologia , Estudos de Casos e Controles , Bovinos , Masculino , Variações Dependentes do Observador , Reprodutibilidade dos Testes , Ultrassonografia/normas
16.
BMC Vet Res ; 14(1): 244, 2018 Aug 22.
Artigo em Inglês | MEDLINE | ID: mdl-30134904

RESUMO

BACKGROUND: Pasteurella multocida type A (PmA) is considered a secondary agent of pneumonia in pigs. The role of PmA as a primary pathogen was investigated by challenging pigs with eight field strains isolated from pneumonia and serositis in six Brazilian states. Eight groups of eight pigs each were intranasally inoculated with different strains of PmA (1.5 mL/nostril of 10e7 CFU/mL). The control group (n = 12) received sterile PBS. The pigs were euthanized by electrocution and necropsied by 5 dpi. Macroscopic lesions were recorded, and swabs and fragments of thoracic and abdominal organs were analyzed by bacteriological and pathological assays. The PmA strains were analyzed for four virulence genes (toxA: toxin; pfhA: adhesion; tbpA and hgbB: iron acquisition) by PCR and sequencing and submitted to multilocus sequence typing (MLST). RESULTS: The eight PmA strains were classified as follows: five as highly pathogenic (HP) for causing necrotic bronchopneumonia and diffuse fibrinous pleuritis and pericarditis; one as low pathogenic for causing only focal bronchopneumonia; and two as nonpathogenic because they did not cause injury to any pig. PCR for the gene pfhA was positive for all five HP isolates. Sequencing demonstrated that the pfhA region of the HP strains comprised four genes: tpsB1, pfhA1, tpsB2 and pfhA2. The low and nonpathogenic strains did not contain the genes tpsB2 and pfhA2. A deletion of four bases was observed in the pfhA gene in the low pathogenic strain, and an insertion of 37 kb of phage DNA was observed in the nonpathogenic strains. MLST clustered the HP isolates in one group and the low and nonpathogenic isolates in another. Only the nonpathogenic isolates matched sequence type 10; the other isolates did not match any type available in the MLST database. CONCLUSIONS: The hypothesis that some PmA strains are primary pathogens and cause disease in pigs without any co-factor was confirmed. The pfhA region, comprising the genes tpsB1, tpsB2, pfhA1 and pfhA2, is related to the pathogenicity of PmA. The HP strains can cause necrotic bronchopneumonia, fibrinous pleuritis and pericarditis in pigs and can be identified by PCR amplification of the gene pfhA2.


Assuntos
Infecções por Pasteurella/veterinária , Pasteurella multocida/genética , Pasteurella multocida/patogenicidade , Doenças dos Suínos/microbiologia , Animais , Brasil , Broncopneumonia/microbiologia , Broncopneumonia/veterinária , Genes Bacterianos , Tipagem de Sequências Multilocus/veterinária , Infecções por Pasteurella/genética , Pasteurella multocida/isolamento & purificação , Pericardite/microbiologia , Pericardite/veterinária , Pleurisia/microbiologia , Pleurisia/veterinária , Reação em Cadeia da Polimerase/veterinária , Suínos , Virulência/genética
17.
Vet Microbiol ; 221: 105-113, 2018 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-29981695

RESUMO

Specific nasopharyngeal bacterial communities can provide colonization resistance against respiratory pathogens in cattle. However, the role of bacterial communities of the lower airways in respiratory health remains largely unknown. Therefore, our objective was to compare nasopharyngeal and tracheal bacterial communities between healthy feedlot cattle and those with bronchopneumonia (BP). Deep nasal swabs and trans-tracheal aspiration samples were collected from steers with (n = 60) and without (n = 60) BP at 4 feedlots in Western Canada. After DNA extraction, 16S rRNA gene (V4) was amplified and sequenced. Alpha-diversity analysis revealed a lower bacterial diversity in the nasopharynx and trachea of steers with BP compared to healthy pen-mates. Bacterial communities present within the airways clustered into 4 distinct metacommunities that were associated with sampling locations and health status. Metacommunity 1, enriched with Mycoplasma bovis, Mannheimia haemolytica and Pasteurella multocida, was dominant in the nasopharynx and trachea of steers with BP. In contrast, metacommunity 3, enriched with Mycoplasma dispar, Lactococcus lactis and Lactobacillus casei, was mostly present in the trachea of healthy steers. Metacommunity 4, enriched with Corynebacterium, Jeotgalicoccus, Psychrobacter and Planomicrobium, was present in the nasopharynx only. Metacommunity 2, enriched with Histophilus somni, Moraxella and L. lactis, was present in both healthy and sick steers, but was primarily detected in one feedlot. We concluded that distinct bacterial metacommunities inhabited the nasopharynx and trachea of healthy feedlot cattle and those with BP. Because L. lactis and L. casei can inhibit M. haemolytica growth in vitro, their presence in healthy steers may have provided colonization resistance against bacterial respiratory pathogens.


Assuntos
Bactérias/classificação , Broncopneumonia/veterinária , Doenças dos Bovinos/microbiologia , Sistema Respiratório/microbiologia , Animais , Bactérias/isolamento & purificação , Broncopneumonia/microbiologia , Bovinos , Masculino
18.
Artigo em Inglês | MEDLINE | ID: mdl-30017079

RESUMO

Streptococcus suis is a major Gram-positive swine pathogen associated with a wide variety of diseases in pigs. The efforts made to develop vaccines against this pathogen have failed because of lack of common cross-reactive antigens against different serotypes. Nowadays the interest has moved to surface and secreted proteins, as they have the highest chances to raise an effective immune response because they are in direct contact with host cells and are really exposed and accessible to antibodies. In this work, we have performed a comparative immunosecretomic approach to identify a set of immunoreactive secreted proteins common to the most prevalent serotypes of S. suis. Among the 67 proteins identified, three (SSU0020, SSU0934, and SSU0215) were those predicted extracellular proteins most widely found within the studied serotypes. These immunoreactive proteins may be interesting targets for future vaccine development as they could provide possible cross-reactivity among different serotypes of this pathogen.


Assuntos
Antígenos de Bactérias/isolamento & purificação , Proteínas de Bactérias/isolamento & purificação , Infecções Estreptocócicas/veterinária , Streptococcus suis/imunologia , Doenças dos Suínos/prevenção & controle , Animais , Antígenos de Bactérias/biossíntese , Antígenos de Bactérias/imunologia , Artrite/imunologia , Artrite/microbiologia , Artrite/prevenção & controle , Artrite/veterinária , Proteínas de Bactérias/imunologia , Proteínas de Bactérias/metabolismo , Broncopneumonia/imunologia , Broncopneumonia/microbiologia , Broncopneumonia/prevenção & controle , Broncopneumonia/veterinária , Eletroforese em Gel Bidimensional , Meningite/imunologia , Meningite/microbiologia , Meningite/prevenção & controle , Meningite/veterinária , Sorogrupo , Espectrometria de Massas por Ionização e Dessorção a Laser Assistida por Matriz , Infecções Estreptocócicas/imunologia , Infecções Estreptocócicas/microbiologia , Infecções Estreptocócicas/prevenção & controle , Vacinas Estreptocócicas/biossíntese , Streptococcus suis/crescimento & desenvolvimento , Streptococcus suis/metabolismo , Streptococcus suis/patogenicidade , Suínos , Doenças dos Suínos/imunologia , Doenças dos Suínos/microbiologia
19.
Braz. J. Vet. Res. Anim. Sci. (Online) ; 55(1): 1-6, 2 abr. 2018. tab
Artigo em Inglês | LILACS, VETINDEX | ID: biblio-912760

RESUMO

The bronchopneumonia of calves represents a risk to national supply chain because it is an ecopathy and weakens the more intensive production systems. It is characterized by inflammatory changes in the bronchi, bronchioles, lung parenchyma, and pleura. It is a disease of multifactorial traits called Bovine Respiratory Disease (BRD). The association of infectious agents with host defense and management to which the animal is subjected leads to the emergence of major clinical manifestations of the disease. The clinical evolution of BRD can also have serious secondary changes such as pulmonary edema, sepsis, and pulmonary hypertension, or even be consequent to the involvement of other structures, such as in cases of myocarditis leading to congestive heart failure. Although this report refers to a non-experimental framework, the circumstances that caused the calf to be subjected to a protocol-specific respiratory assessment involving non-routine reviews has made it possible to associate circulatory and respiratory conditions, rarely considered in ruminant clinic. The focus of this report was pulmonary edema. Modern clinical vision requires of the veterinarian work with cost-benefit relation, so that the more accurate and the earlier the clinical diagnosis the less expensive the treatment.(AU)


A broncopneumonia dos bezerros representa um risco à cadeia produtiva nacional por ser uma ecopatia e fragilizar os sistemas mais intensivos de produção. É caracterizada por alterações inflamatórias de brônquios, bronquíolos, parênquima pulmonar e pleura. Por ser uma doença de características multifatoriais é denominada Complexo Doença Respiratória de Bovinos (CDRB). A interação dos agentes infecciosos, a defesa do hospedeiro e o manejo ao qual o animal é submetido determinam as principais manifestações clínicas da doença. A evolução clínica do CDRB também pode apresentar alterações secundárias graves como o edema pulmonar, septicemia e a hipertensão pulmonar, ou mesmo ser consequente ao acometimento de outras estruturas, como nos casos de miocardite que levam à insuficiência cardíaca congestiva. Apesar deste relato referir-se a um quadro não experimental, as circunstâncias de submissão a um protocolo de avaliação respiratória específico, envolvendo avaliações não rotineiras, permitiu a o estabelecimento da associação entre as interações circulatórias e o quadro respiratório, pouco consideradas na clínica de ruminantes. A referência do presente relato foi o edema pulmonar. A visão clínica moderna obriga o médico veterinário a trabalhar a relação custo-benefício e, quanto mais acurado e precoce é o diagnóstico clínico, menos dispendioso é o tratamento.(AU)


Assuntos
Animais , Masculino , Lactente , Bovinos , Complexo Respiratório Bovino/diagnóstico , Complexo Respiratório Bovino/terapia , Edema Pulmonar/veterinária , Broncopneumonia/veterinária , Miocardite/veterinária , Sepse/veterinária
20.
J Infect Dis ; 218(2): 218-227, 2018 06 20.
Artigo em Inglês | MEDLINE | ID: mdl-29566184

RESUMO

Background: The emerging zoonotic paramyxovirus Nipah virus (NiV) causes severe respiratory and neurological disease in humans, with high fatality rates. Nipah virus can be transmitted via person-to-person contact, posing a high risk for epidemic outbreaks. However, a broadly applicable approach for human NiV outbreaks in field settings is lacking. Methods: We engineered new antiviral lipopeptides and analyzed in vitro fusion inhibition to identify an optimal candidate for prophylaxis of NiV infection in the lower respiratory tract, and we assessed antiviral efficiency in 2 different animal models. Results: We show that lethal NiV infection can be prevented with lipopeptides delivered via the respiratory route in both hamsters and nonhuman primates. By targeting retention of peptides for NiV prophylaxis in the respiratory tract, we avoid its systemic delivery in individuals who need only prevention, and thus we increase the safety of treatment and enhance utility of the intervention. Conclusions: The experiments provide a proof of concept for the use of antifusion lipopeptides for prophylaxis of lethal NiV. These results advance the goal of rational development of potent lipopeptide inhibitors with desirable pharmacokinetic and biodistribution properties and a safe effective delivery method to target NiV and other pathogenic viruses.


Assuntos
Quimioprevenção/métodos , Infecções por Henipavirus/prevenção & controle , Lipopeptídeos/administração & dosagem , Vírus Nipah/fisiologia , Doenças dos Primatas/prevenção & controle , Proteínas do Envelope Viral/antagonistas & inibidores , Inibidores de Proteínas Virais de Fusão/administração & dosagem , Animais , Broncopneumonia/prevenção & controle , Broncopneumonia/veterinária , Modelos Animais de Doenças , Feminino , Humanos , Masculino , Mesocricetus
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