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1.
BMC Vet Res ; 20(1): 83, 2024 Mar 07.
Artigo em Inglês | MEDLINE | ID: mdl-38454460

RESUMO

BACKGROUND: Anticoagulant rodenticide (AR) poisoning was diagnosed in 3 Patagonian maras (Dolichotis patagonum) raised in the mara farm in Thailand. To date, there have been no reports of maras with diagnosed AR poisoning. CASE PRESENTATION: The first clinical sign of the sickening maras was anorexia. Fifteen from 50 maras were dead over a 3-5 day period after the clinical signs had occurred. Positive results to AR were detected in all of the maras' liver specimens by screening test using thin layer chromatography and spectrophotometry methods. Supportive therapy was selected for the treatment of the 35 surviving maras. During the follow - up observation period of 12 months, all of the surviving maras were healthy and no reproductive loss. CONCLUSIONS: This is the first report on suspected AR poisoning in maras in Thailand based on history taking, clinical signs, gross pathology lesions and chemical analysis. AR poisoning in the present report is possibly from contaminated animal food. Therefore, quality control of food should be fastidious when feeding maras.


Assuntos
Doenças dos Roedores , Rodenticidas , Animais , Fazendas , Roedores , Anticoagulantes
2.
Acta Trop ; 249: 107070, 2024 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-37956819

RESUMO

Instances of reverse zoonosis involving severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) has been documented in both controlled experiments and spontaneous cases. Although dogs are susceptible to infection, clinical significance is limited to mild or asymptomatic. Here, we investigate the fatal cases of natural SARS-CoV-2 infection in dogs in Thailand. Pathological findings of SARS-CoV-2-infected dogs reveal severe diffuse alveolar damage, pulmonary hyalinization and fibrosis, and syncytial formation, together with minor lesions in brain and kidney. Employing reverse transcription-digital PCR, substantial viral loads of SARS-CoV-2 were detected in lung, kidney, brain, trachea, tonsil, tracheobronchial lymph node, liver, and intestine, respectively. Localization of SARS-CoV-2 within various tissues was examined through immunohistochemistry (IHC), where the co-localization of the viral spike protein and the angiotensin-converting enzyme 2 (ACE2) receptor was illustrated using double IHC. SARS-CoV-2 localization was markedly identified in the epithelial cells of the lung, trachea, intestine and kidneys, and moderately presented in the salivary gland and gall bladder, where the co-localization with the ACE2 was also evident. Neurons in the brainstem where exhibited lymphocytic perivascular cuffing were also found to be positive for SARS-CoV-2 in IHC testing, despite lacking ACE2 receptor expression. In addition, SARS-CoV-2 replication within the lungs of infected dogs was confirmed by transmission electron microscopy, visualizing free viral particles within the cytosol or the endoplasmic reticulum of syncytial cells within the lung. This study considerably expanded on the knowledge of the pathology associated with natural SARS-CoV-2 infection in dogs, a scenario that is relatively infrequent but occasionally leads to fatal outcome. Furthermore, these findings suggest the potential utility of dogs as a model for studying SARS-CoV-2 infection in humans, warranting further investigation.


Assuntos
COVID-19 , Humanos , Cães , Animais , COVID-19/veterinária , SARS-CoV-2 , Enzima de Conversão de Angiotensina 2 , Carga Viral , Peptidil Dipeptidase A/metabolismo
3.
Vet Res Commun ; 47(3): 1457-1469, 2023 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-37036600

RESUMO

Using the matrix-assisted laser desorption/ionization-time-of-flight mass spectrometry (MALDI-TOF MS) method for bacterial diagnosis, rapid urine sample preparation can reduce time relapsing of diagnosis and improve discriminatory power in coinfection cases. We aimed to evaluate rapid urine preparation procedures before MALDI-TOF MS application using dog clinical urine samples in comparison with standard microbiological diagnostic methods by agreement analysis. We determined the frequency and distribution of bacteria and bacterial resistance and their correlations to clinical history. Three experimental procedures comprising direct centrifugation, 10% sodium dodecyl sulfate digestion, and ultrasonic preparation were performed for method validation and sensitivity. Sterile urine containing Escherichia coli and/or Staphylococcus aureus were used as simulated samples. By ultrasonic preparation, the microorganisms could be detected 1.46-1.51 × 105 CFU, which was considered the most suitable technique. This preparation was significantly consistent with the routine method based on data from Hospital Information Systems for 50 urine samples from canine cystitis. By standard protocol, Enterobacteriaceae and Staphylococcus pseudintermedius were found in most of the 155 urine samples with cystitis. Extended-spectrum beta-lactamase-producing Enterobacteriaceae was found in 25-30% of the samples. Imipenem resistance was found in 70% of Acinetobacter baumannii cases; almost all were resistant to second-generation fluoroquinolones and tetracyclines. The most efficient antibiotic for treating bacterial urinary tract infection was amoxicillin plus clavulanic acid. A. baumannii and Pseudomonas aeruginosa were susceptible to pradofloxacin. Prolonged urine catheterization was linked to lower urinary tract infections by Enterobacter spp., which also correlated with chronic kidney disease.


Assuntos
Cistite , Doenças do Cão , Infecções Urinárias , Cães , Animais , Antibacterianos/farmacologia , Antibacterianos/uso terapêutico , Farmacorresistência Bacteriana , Bactérias , Espectrometria de Massas por Ionização e Dessorção a Laser Assistida por Matriz/veterinária , Espectrometria de Massas por Ionização e Dessorção a Laser Assistida por Matriz/métodos , Infecções Urinárias/diagnóstico , Infecções Urinárias/tratamento farmacológico , Infecções Urinárias/veterinária , Cistite/veterinária , Lasers , Doenças do Cão/diagnóstico , Doenças do Cão/tratamento farmacológico
4.
Virol J ; 19(1): 162, 2022 10 12.
Artigo em Inglês | MEDLINE | ID: mdl-36224594

RESUMO

BACKGROUND: Influenza A virus causes respiratory disease in many animal species as well as in humans. Due to the high human-animal interface, the monitoring of canine influenza in dogs and the study of the transmission and pathogenicity of canine influenza in animals are important. METHODS: Eight-week-old beagle dogs (Canis lupus familaris) (n = 13) were used for the intraspecies transmission model. The dogs were inoculated intranasally with 1 ml of 106 EID50 per ml of canine H3N2 influenza virus (A/canine/Thailand/CU-DC5299/2012) (CIV-H3N2). In addition, 4-week-old guinea pigs (Cavia porcellus) (n = 20) were used for the interspecies transmission model. The guinea pigs were inoculated intranasally with 300 µl of 106 EID50 per ml of CIV-H3N2. RESULTS: For the Thai CIV-H3N2 challenged in the dog model, the incoculated and direct contact dogs developed respiratory signs at 2 dpi. The dogs shed the virus in the respiratory tract at 1 dpi and developed an H3-specific antibody against the virus at 10 dpi. Lung congestion and histopathological changes in the lung were observed. For the Thai CIV-H3N2 challenge in the guinea pig model, the incoculated, direct contact and aerosol-exposed guinea pigs developed fever at 1-2 dpi. The guinea pigs shed virus in the respiratory tract at 2 dpi and developed an H3-specific antibody against the virus at 7 dpi. Mild histopathological changes in the lung were observed. CONCLUSION: The result of this study demonstrated evidence of intraspecies and interspecies transmission of CIV-H3N2 in a mammalian model.


Assuntos
Doenças do Cão , Influenza Humana , Infecções por Orthomyxoviridae , Animais , Cães , Cobaias , Humanos , Vírus da Influenza A Subtipo H3N2 , Influenza Humana/patologia , Pulmão/patologia , Mamíferos , Virulência
5.
Vet Med Sci ; 8(6): 2283-2291, 2022 11.
Artigo em Inglês | MEDLINE | ID: mdl-36173734

RESUMO

Gastrointestinal pythiosis is a severe, progressive and often a fatal disease, which is caused by the aquatic pathogen Pythium insidiosum. Treatment is challenging due to the disease's resistance to antifungal drugs. Surgical resection is frequently attempted in cases of pythiosis; however, it can be technically challenging. This report presents two dogs with decreased appetite, abdominal pain, progressive haematochezia, tenesmus and significant weight loss. With the medical histories of both being young canines, living in areas with access to natural water resources and with the main chronic gastrointestinal symptoms having not responded to symptomatic treatment, pythiosis was taken into consideration. Abdominal ultrasound revealed severe, diffuse thickening and loss of normal layering of the colonic wall. These findings led to a differential diagnosis between intestinal neoplasia and fungal disease. Full-thickness biopsies were later performed, and immunohistochemistry staining was suggested for colonic pythiosis. Medical treatment for pythiosis was successful with a combination of oral terbinafine and prednisolone. However, therapy with itraconazole in case 1 did not improve the clinical signs, and in case 2, itraconazole was used after all clinical signs have improved for clinical control. Since then, there has been no recurrence of clinical signs until the time of preparing this report (19 months for case 1, 11 months for case 2 since the cessation of treatment). The treatment was successful based on clinical signs and ultrasonographic data, and the disease remission was not confirmed by advance imaging, monitoring of pythiosis enzyme-linked immunosorbent essay concentration or repeat sampling.


Assuntos
Doenças do Cão , Pitiose , Cães , Animais , Pitiose/diagnóstico , Pitiose/tratamento farmacológico , Pitiose/microbiologia , Antifúngicos/uso terapêutico , Itraconazol/uso terapêutico , Tailândia , Doenças do Cão/diagnóstico por imagem , Doenças do Cão/tratamento farmacológico
6.
Front Vet Sci ; 8: 759814, 2021.
Artigo em Inglês | MEDLINE | ID: mdl-34722714

RESUMO

Anatrichosoma spp. is a group of trichuroid nematodes that mainly infect non-human primates and domestic cats. The lifecycle of these nematodes remains unclear. In non-human primates, Anatrichosoma spp. were found in the nasal cavity. However, ulcerative dermatitis has been reported in infected cats. An adult, intact, female domestic short-haired cat was presented with ulcerative pododermatitis of all limbs. Punch biopsy was performed at the edge of the ulcerative wound for histopathological investigation and showed necrosis and infiltration of inflammatory cells around the nematode-like lesion. Eggs with Capillaria-like characteristics were present. Tissue sections were subjected to DNA extraction and PCR targeting 18S rRNA, using primers designed from Anatrichosoma 18S rRNA. The phylogenetic tree revealed that DNA obtained from the lesion of the domestic cat was grouped with Anatrichosoma spp. from the olive glass mouse (Abothirx olivacea), Capillaria plica and Eucoleus aerophilus, both from the red fox (Vulpes Vulpes). The study is the first report of feline anatrichosomiasis in Thailand, and we present both pathological findings and molecular evidence. The cat was successfully treated with emodepsine/praziquantel. The skin lesion recovered within 3 days after anthelmintic treatment. Because Anatrichosoma spp. have been reported in humans, the zoonotic potential of this parasite should be considered.

7.
Emerg Infect Dis ; 27(8): 2208-2211, 2021 08.
Artigo em Inglês | MEDLINE | ID: mdl-34287126

RESUMO

To investigate an outbreak of African horse sickness (AHS) on a horse farm in northeastern Thailand, we used whole-genome sequencing to detect and characterize the virus. The viruses belonged to serotype 1 and contained unique amino acids (95V,166S, 660I in virus capsid protein 2), suggesting a single virus introduction to Thailand.


Assuntos
Vírus da Doença Equina Africana , Doença Equina Africana , Doença Equina Africana/epidemiologia , Vírus da Doença Equina Africana/genética , Animais , Fazendas , Cavalos , Sorogrupo , Tailândia/epidemiologia
8.
Access Microbiol ; 2(4): acmi000109, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-33005872

RESUMO

INTRODUCTION: Pythium insidiosum causes pythiosis in humans and animals in tropical and subtropical climates. The clinical manifestations in humans are mostly systemic, vascular or ocular forms, in contrast to animals, which are cutaneous, subcutaneous and gastrointestinal forms. The highest incidence of human cases is reported in Thailand, however, no canine pythiosis has been documented yet. CASE PRESENTATION: A female, mixed-breed, stray dog showed severe extensive ulcerative haemorrhagic dermatitis at the perineum involving the anus and tail. On cytology, there were sparse branching septate fungal hyphae. The tissue samples were subjected to polymerase chain reaction and gene sequencing for fungal identification. CONCLUSION: The results of the internal transcribed spacer 1 and 2 (ITS1 and ITS2) gene had 99 % homology to Pythium insidiosum (accession no. FJ17396) and the COX2 gene (accession no. GQ451572). The phylogenetic tree of both genes was classified in clade ATH. This is the first fully documented diagnosis of canine cutaneous pythiosis in Thailand.

9.
Dis Aquat Organ ; 134(2): 99-106, 2019 May 02.
Artigo em Inglês | MEDLINE | ID: mdl-31043577

RESUMO

Over the span of several years, 3 Indo-Pacific humpbacked dolphins died and were necropsied in Thailand. These 3 animals were all captive-bred at Oasis Sea World (Chanthaburi, Thailand), and displayed similar macroscopic progressive cutaneous lesions diagnosed as squamous cell carcinomas. In 2 of the 3 animals, necropsy revealed a severe fibrinosuppurative tracheitis and pneumonia secondary to metastasis of a cutaneous squamous cell carcinoma which extended from the head throughout the trunk and flippers. The tumors were characterized by coalescing botryoid masses with severe areas of cutaneous erosion, ulceration and necrohemorrhagic dermatitis. There was evidence of metastasis to the lungs and hilar lymph nodes. Necropsy of the third animal revealed similar progressive cutaneous squamous cell carcinomas but without evidence of metastasis. DNA molecular analysis of homogenized neoplastic tissue was conducted using polymerase chain reaction for both herpesvirus and papillomavirus in 2 of the 3 cases. In the first case, the tissues were positive for a herpesvirus alone, and this was phylogenetically classified as an alphaherpesvirus. This new herpesvirus has been tentatively named Sousa chinensis alphaherpesvirus. The second animal was negative for this novel herpesvirus and the third was not analyzed. In addition to the captive population, there is photographic evidence from 2 separate wild populations of Indo-Pacific humpbacked dolphins in the Gulf of Thailand, of a macroscopically identical proliferative and ulcerative process suspected to be squamous cell carcinomas.


Assuntos
Carcinoma de Células Escamosas , Golfinhos , Neoplasias Cutâneas , Animais , Carcinoma de Células Escamosas/veterinária , Neoplasias Cutâneas/veterinária , Tailândia
10.
Vet Microbiol ; 220: 12-17, 2018 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-29885795

RESUMO

The major objective of this work was to investigate the shedding of porcine circovirus type 3 (PCV3) in sow colostrum. PCV3 titers in the serum and colostrum samples of 38 sows were determined using qPCR. Interestingly, this is the first report regarding the identification of PCV3 from the colostrum samples. In the studied farm, the prevalence of PCV3 in the colostrum samples was 44.74% (17/38). When sows were grouped based on the PCV3 titers in the serum into the "High-viremic", "Low-viremic" and "Non-viremic" sows, it was shown that the High-viremic sows showed significantly higher PCV3 colostrum prevalence (100%; 9/9) with the PCV3 titers ranging from 4.01 to 7.33 genomic copies/mL. The results indicated that PCV3 in the colostrum might be partly influenced by the viremic stage of the infection. However, the results also showed that approximately 41% of sows shedding PCV3 with low titers in the colostrum (7/17) were non-viremic sows. In conclusion, this study identified the presence of PCV3 in sow colostrum. Clinical impacts and mechanisms of colostrum shedding of PCV3 should be further investigated.


Assuntos
Infecções por Circoviridae/veterinária , Circovirus/fisiologia , Colostro/virologia , Suínos/virologia , Eliminação de Partículas Virais , Animais , Anticorpos Antivirais/sangue , Infecções por Circoviridae/sangue , Infecções por Circoviridae/epidemiologia , Infecções por Circoviridae/virologia , Circovirus/genética , Feminino , Gravidez , Prevalência , Reação em Cadeia da Polimerase em Tempo Real , Doenças dos Suínos/epidemiologia , Doenças dos Suínos/virologia , Tailândia/epidemiologia , Viremia/epidemiologia
11.
Sci Rep ; 8(1): 7524, 2018 05 14.
Artigo em Inglês | MEDLINE | ID: mdl-29760429

RESUMO

Canine circoviruses (CanineCV's), belonging to the genus Circovirus of the Circoviridae family, were detected by next generation sequencing in samples from Thai dogs with respiratory symptoms. Genetic characterization and phylogenetic analysis of nearly complete CanineCV genomes suggested that natural recombination had occurred among different lineages of CanineCV's. Similarity plot and bootscaning analyses indicated that American and Chinese viruses had served as major and minor parental viruses, respectively. Positions of recombination breakpoints were estimated using maximum-likelihood frameworks with statistical significant testing. The putative recombination event was located in the Replicase gene, intersecting with open reading frame-3. Analysis of nucleotide changes confirmed the origin of the recombination event. This is the first description of naturally occurring recombinant CanineCV's that have resulted in the circulation of newly emerging CanineCV lineages.


Assuntos
Infecções por Circoviridae/veterinária , Circovirus/classificação , Doenças do Cão/virologia , Sequenciamento de Nucleotídeos em Larga Escala/veterinária , Doenças Respiratórias/veterinária , Animais , Infecções por Circoviridae/virologia , Circovirus/genética , Circovirus/isolamento & purificação , Cães , Evolução Molecular , Tamanho do Genoma , Genoma Viral , Filogenia , Recombinação Genética , Doenças Respiratórias/virologia , Análise de Sequência de DNA/veterinária , Tailândia
12.
Trop Anim Health Prod ; 50(7): 1509-1518, 2018 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-29696456

RESUMO

The Chinese highly pathogenic porcine reproductive and respiratory syndrome virus (HP-PRRSV) has caused a severe threat to the pig population in Southeast Asian countries. The purpose of this study was to investigate the efficacy of a type 2 PRRSV modified live vaccine (PrimePac™ PRRS, lineage 7) against a Thai HP-PRRSV (10PL01, lineage 8). Three-week-old PRRSV-free pigs were randomly assigned into three groups. Vaccinated challenged group (group 1, n = 16) was immunized with PrimePac™ PRRS vaccine at 3 weeks old. The unvaccinated challenged group (group 2, n = 16) was injected with PBS at 3 weeks old, and unvaccinated unchallenged group (group 3, n = 10) was served as a negative control. At 9 weeks old, all groups, except the negative control group, were challenged with the Thai HP-PRRSV. All pigs were monitored daily during 10 days post-infection (dpi) and were necropsied at 10 and 17 dpi. The results revealed that vaccinated challenged pigs showed significantly lower (p < 0.05) mean rectal temperatures, clinical respiratory scores, lung lesion scores, and levels of virus load in serum and lung tissue compared with the unvaccinated challenged pigs. Moreover, vaccinated challenged pigs exhibited PRRSV-specific serum neutralizing antibodies at the end of the experiment. Our findings indicated that the studied type 2 PRRSV vaccine provided partial protection against the Thai HP-PRRSV infection based on the body temperature, levels of viremia, and the severity of lung lesions. These results demonstrated that partial protection of PrimePac™ PRRS vaccine might be useful for controlling HP-PRRSV infection in the endemic area.


Assuntos
Anticorpos Antivirais/sangue , Síndrome Respiratória e Reprodutiva Suína/prevenção & controle , Vacinas Virais/imunologia , Criação de Animais Domésticos/métodos , Animais , Anticorpos Neutralizantes/sangue , Genótipo , Leucócitos Mononucleares/citologia , Síndrome Respiratória e Reprodutiva Suína/imunologia , Vírus da Síndrome Respiratória e Reprodutiva Suína , RNA Viral/análise , Suínos , Tailândia , Vacinação/veterinária , Vacinas Atenuadas/imunologia , Viremia/imunologia
13.
Vet Microbiol ; 215: 71-76, 2018 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-29426409

RESUMO

Porcine circovirus type 3 (PCV3) is a newly emerging virus with unknown pathogenesis. The major objective of this study was to investigate the presence of PCV3 in pigs from a farm in Thailand suffering from porcine respiratory disease complex (PRDC). Initially, a Thai PCV3 strain (PCV3/Thailand/PB01/17) was identified from a pig originated from a farm with PRDC problem during grower period and whole genome analysis showed that the Thai PCV3 shared highest nucleotide identity of 99.60% with the South Korean strain PCV3/KU-1602. The presence of PCV3 infection in PRDC-affected pigs was then investigated in this farm. Serum samples from clinically healthy pigs and pigs showing PRDC-related clinical signs during 5-18 weeks were used in PCV3 detection by PCR. The results showed that the PRDC-affected pigs exhibited higher prevalence of PCV3 infection and higher PCV3 titers comparing with the clinically healthy pigs. These results confirmed the presence of PCV3 in a Thai farm with PRDC problem. The pathogenesis of PCV3 on PRDC should be clarified in further studies.


Assuntos
Infecções por Circoviridae/veterinária , Circovirus/fisiologia , Doenças Respiratórias/veterinária , Doenças dos Suínos/virologia , Animais , Infecções por Circoviridae/complicações , Infecções por Circoviridae/epidemiologia , Infecções por Circoviridae/virologia , Circovirus/genética , Coinfecção , Fazendas , Prevalência , Doenças Respiratórias/complicações , Doenças Respiratórias/epidemiologia , Doenças Respiratórias/virologia , Homologia de Sequência do Ácido Nucleico , Especificidade da Espécie , Suínos , Doenças dos Suínos/epidemiologia , Tailândia/epidemiologia
14.
Res Vet Sci ; 114: 6-11, 2017 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-28267619

RESUMO

Since the pandemic H1N1 emergence in 2009 (pdmH1N1), many reassortant pdmH1N1 viruses emerged and found circulating in the pig population worldwide. Currently, commercial human subunit vaccines are used commonly to prevent the influenza symptom based on the WHO recommendation. In case of current reassortant swine influenza viruses transmitting from pigs to humans, the efficacy of current human influenza vaccines is of interest. In this study, influenza A negative pigs were vaccinated with selected commercial human subunit vaccines and challenged with rH3N2. All sera were tested with both HI and SN assays using four representative viruses from the surveillance data in 2012 (enH1N1, pdmH1N1, rH1N2 and rH3N2). The results showed no significant differences in clinical signs and macroscopic and microscopic findings among groups. However, all pig sera from vaccinated groups had protective HI titers to the enH1N1, pdmH1N1 and rH1N2 at 21DPV onward and had protective SN titers only to pdmH1N1and rH1N2 at 21DPV onward. SN test results appeared more specific than those of HI tests. All tested sera had no cross-reactivity against the rH3N2. Both studied human subunit vaccines failed to protect and to stop viral shedding with no evidence of serological reaction against rH3N2. SIV surveillance is essential for monitoring a novel SIV emergence potentially for zoonosis.


Assuntos
Vírus da Influenza A Subtipo H1N1 , Vacinas contra Influenza/imunologia , Infecções por Orthomyxoviridae/veterinária , Doenças dos Suínos/prevenção & controle , Animais , Reações Cruzadas , Vírus da Influenza A Subtipo H3N2/imunologia , Infecções por Orthomyxoviridae/prevenção & controle , Infecções por Orthomyxoviridae/virologia , Vírus Reordenados , Suínos , Doenças dos Suínos/virologia , Eliminação de Partículas Virais
15.
Vet Immunol Immunopathol ; 183: 7-15, 2017 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-28063479

RESUMO

Porcine reproductive and respiratory syndrome virus (PRRSV) infection is one of the most important swine pathogens, and causes a major economic impact worldwide. Recently, a new variant type 2 PRRSV, highly pathogenic PRRSV (HP-PRRSV) has emerged and continued to circulate in Southeast Asia region. Currently, commercially available PRRSV vaccines, modified live PRRS vaccines (MLV) are not able to provide complete protection against HP-PRRSV and been reported to induce negative immunomodulatory effects. Interestingly, a novel DNA vaccine was developed and successfully used to improve PRRSV-specific immune responses following MLV vaccination. To investigate the efficacy of a heterologous DNA-MLV prime-boost immunization against the HP-PRRSV infection, an experimental vaccinated-challenged study was conducted. Two-week-old, PRRSV-seronegative, crossbred pigs (5-8 pigs/group) were allocated into 5 groups. At day -14 (D-14), the treatment group (DNA-MLV) was immunized with a DNA vaccine encoding PRRSV-truncated nucleocapsid protein (pORF7t), followed by a commercial modified live type 2 PRRS vaccine (MLV) at D0. The other groups included the group that received PBS at D-14 followed by MLV at D0 (MLV), pORF7t at D-14 (DNA), PBS at D0 (PBS) and the negative control group. At D42, all groups, except the negative control group, were challenged with HP-PRRSV (strain 10PL1). The results demonstrated that pigs that received MLV, regardless of the DNA priming, exhibited less clinical signs and faster viral clearance. Following HP-PRRSV challenge, the DNA-MLV group exhibited improved PRRSV-specific immunity, as observed by increased neutralizing antibody titers and PRRSV-specific IFN-γ production, and reduced IL-10 and PRRSV-specific Treg productions. However, neither the prime-boost immunization nor the MLV was able to induce complete clinical protection against HP-PRRSV infection. In conclusion, improved immunological responses, but not clinical protection, were achieved by DNA-MLV prime-boost immunization. This study highlights the potential use of heterologous prime-boost vaccination regimen, where DNA can be incorporated with other vaccine candidates, for improving anti-PRRSV immunity that may eventually lead induction of complete PRRSV protection.


Assuntos
Síndrome Respiratória e Reprodutiva Suína/prevenção & controle , Vírus da Síndrome Respiratória e Reprodutiva Suína , Vacinas de DNA/administração & dosagem , Animais , Imunidade Celular , Imunidade Humoral , Imunização Secundária/veterinária , Imunogenicidade da Vacina , Síndrome Respiratória e Reprodutiva Suína/patologia , Vírus da Síndrome Respiratória e Reprodutiva Suína/imunologia , Suínos , Vacinas Atenuadas/administração & dosagem
16.
Trop Anim Health Prod ; 48(7): 1351-9, 2016 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-27315207

RESUMO

Recently, the Chinese highly pathogenic porcine reproductive and respiratory syndrome virus (PRRSV) (HP-PRRSV) belonging to lineage 8 causes severe symptom with high morbidity and high mortality rates to the Asian pig industry. A recent study showed that pigs immunized with Fostera® PRRS modified live virus (MLV) of lineage 8 could provide a degree of protection against a Vietnamese HP-PRRSV infection. It should be noted that PRRSV commonly found after weaning causes porcine respiratory disease complex (PRDC). Vaccination strategy should be evaluated in each farm scenario. Eighty-one PRRSV-free piglets obtained from a PRRS-free herd were divided into two experiments with the major difference of infection timing after vaccination, 42 days in experiment 1 (n = 42) and 28 days in experiment 2 (n = 39). Each experiment had similar protocol containing three groups including a negative control, unvaccinated challenged, and vaccinated challenged groups. Pigs in vaccination groups were immunized with Fostera® PRRS MLV vaccine at 3 weeks of age. Then, unvaccinated challenged and vaccinated challenged groups were intranasally inoculated with a Thai HP-PRRSV (10PL01). Vaccinated challenged pigs showed significantly lower levels of mean rectal temperatures, clinical severity, lung lesion scores, and viral titers in serum and lung tissue compared to the unvaccinated challenged pigs (p < 0.05). Vaccinated challenged pigs had higher survival rate than those of unvaccinated challenged pigs in both experiments. It should be noted that pigs challenged 42 days after vaccination showed a better performance than pigs challenged 28 days after vaccination. In conclusion, Fostera® PRRS MLV vaccine was able to improve the survival rate against the Thai HP-PRRSV infection in both 42- and 28-day vaccination-to-infection protocols.


Assuntos
Síndrome Respiratória e Reprodutiva Suína/prevenção & controle , Vírus da Síndrome Respiratória e Reprodutiva Suína/imunologia , Vacinação/veterinária , Vacinas Virais/imunologia , Animais , Animais Recém-Nascidos , Anticorpos Antivirais/sangue , Masculino , Síndrome Respiratória e Reprodutiva Suína/mortalidade , Vírus da Síndrome Respiratória e Reprodutiva Suína/patogenicidade , Análise de Sobrevida , Suínos , Tailândia , Clima Tropical , Vacinas Atenuadas/imunologia
17.
Vaccine ; 33(32): 3997-4003, 2015 Jul 31.
Artigo em Inglês | MEDLINE | ID: mdl-26079617

RESUMO

BACKGROUND: Viral-induced interleukin (IL)-10 and regulatory T lymphocytes (Tregs) are believed to play a major role in shaping the immunological and clinical outcomes following Porcine Reproductive and Respiratory Syndrome virus (PRRSV) infection. Recently, it has been shown that PRRSV nucleocapsid (N) protein can induce IL-10 production which is essential for induction of PRRSV-specific Tregs. We hypothesized that immunity to N protein should reduce PRRSV-induced negative immunomodulatory effects which will be essential for establishing proper anti-PRRSV immunity in infected pigs. OBJECTIVES: To investigate the immunomodulatory effects of DNA vaccine encoding a linearized, truncated form of PRRSV-N protein (pORF7t) which was designed to preferentially induce cell-mediated immunity against PRRSV N protein. METHOD: Immunomodulatory effects of the novel DNA vaccine were investigated in an experimental vaccinated-challenged model. In addition, long-term immunomodulatory effects of the DNA vaccine were investigated in vaccinated pigs kept at the PRRSV-positive environment until the end of the fattening period. Pigs were vaccinated either prior to or following natural PRRSV infection. RESULT: The results indicated that pORF7t could modulate the anti-PRRSV immune responses and promote the control of viral replication in the vaccinated-challenged pigs. Immunized pigs exhibited increased numbers of PRRSV-specific activated CD4(+)CD25(+) lymphocytes, reduced numbers of PRRSV-specific Tregs, and rapid viral clearance following infection. In a long-term study, regardless of the time of vaccination, DNA vaccine could modulate the host immune responses, resulted in enhanced PRRSV-specific IFN-γ producing cells, and reduced numbers of PRRSV-specific Tregs, without evidence of enhanced antibody responses. No vaccine adverse reaction was observed throughout the study. CONCLUSION: This study revealed the novel concept that PRRSV-specific immunity can be modulated by induction of cell-mediated immunity against the nucleocapsid protein. This concept could potentially benefit the development of PRRSV management and control strategies.


Assuntos
Tolerância Imunológica , Proteínas do Nucleocapsídeo/imunologia , Síndrome Respiratória e Reprodutiva Suína/imunologia , Vírus da Síndrome Respiratória e Reprodutiva Suína/imunologia , Vacinas de DNA/imunologia , Animais , Masculino , Proteínas do Nucleocapsídeo/genética , Síndrome Respiratória e Reprodutiva Suína/patologia , Síndrome Respiratória e Reprodutiva Suína/prevenção & controle , Suínos , Resultado do Tratamento , Vacinas de DNA/administração & dosagem , Vacinas de DNA/genética
18.
J Vet Med Sci ; 77(9): 1095-100, 2015 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-25960119

RESUMO

The objective of the present study was to determine the number of ovulations in culled Landrace × Yorkshire (LY) crossbred gilts in the tropics associated with age, body weight and growth rate. The genital organs from 316 gilts were examined for gross abnormalities, and those with normal cyclic ovaries (n=155, 307 ± 4.1 days of age, 148 ± 1.6 kg body weight) were included in the analyses. Number of ovulations was defined by a count of the corpora lutea (CL) from both ovaries. On average, the number of ovulations in LY gilts was 15.9 ± 0.3 (range 4 to 27). The number of ovulations correlated with the body weight (r=0.31, P<0.001) and growth rate (r=0.20, P=0.015) of the gilts, but not with their age (P>0.05). Gilts with a body weight of 141 to 150 kg (17.0 CL, n=31) ovulated more than those with a body weight ≤130 kg (14.1 CL, P=0.014, n=23). In conclusion, both the body weight and growth rate of the gilts were significantly correlated with the number of ovulations. The maximum number of ovulations was found in gilts at a body weight of above 141 kg.


Assuntos
Ovulação/fisiologia , Suínos/fisiologia , Fatores Etários , Animais , Peso Corporal/fisiologia , Corpo Lúteo/fisiologia , Feminino , Ovário/fisiologia , Suínos/crescimento & desenvolvimento
20.
Neuropathology ; 34(3): 277-83, 2014 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-24397792

RESUMO

Rabies is a fatal zoonotic disease for which no effective treatment measures are currently available. Rabies virus (RABV) has anti-apoptotic and anti-inflammatory properties that suppress nerve cell damage and inflammation in the CNS. These features imply that the elimination of RABV from the CNS by appropriate treatment could lead to complete recovery from rabies. Ten rabbits showing neuromuscular symptoms of rabies after subcutaneous (SC) immunization using commercially available vaccine containing inactivated whole RABV particles and subsequent fixed RABV (CVS strain) inoculation into hind limb muscles were allocated into three groups. Three rabbits received no further treatment (the SC group), three rabbits received three additional SC immunizations using the same vaccine, and four rabbits received three intrathecal (IT) immunizations, in which the vaccine was inoculated directly into the cerebrospinal fluid (the SC/IT group). An additional three naïve rabbits were inoculated intramuscularly with RABV and not vaccinated. The rabbits exhibited neuromuscular symptoms of rabies within 4-8 days post-inoculation (dpi) of RABV. All of the rabbits died within 8-12 dpi with the exception of one rabbit in the SC group and all four rabbits in SC/IT group, which recovered and started to respond to external stimuli at 11-18 dpi and survived until the end of the experimental period. RABV was eliminated from the CNS of the surviving rabbits. We report here a possible, although still incomplete, therapy for rabies using IT immunization. Our protocol may rescue the life of rabid patients and prompt the future development of novel therapies against rabies.


Assuntos
Imunização/tendências , Vacina Antirrábica/administração & dosagem , Vírus da Raiva/efeitos dos fármacos , Raiva/tratamento farmacológico , Animais , Imunização/mortalidade , Injeções Espinhais , Coelhos , Raiva/mortalidade , Raiva/patologia , Taxa de Sobrevida/tendências
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