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1.
Emerg Infect Dis ; 24(4): 782-785, 2018 04.
Artículo en Inglés | MEDLINE | ID: mdl-29553328

RESUMEN

A putative new lyssavirus was found in 2 Japanese pipistrelles (Pipistrellus abramus) in Taiwan in 2016 and 2017. The concatenated coding regions of the virus showed 62.9%-75.1% nucleotide identities to the other 16 species of lyssavirus, suggesting that it may be representative of a new species of this virus.


Asunto(s)
Lyssavirus , Infecciones por Rhabdoviridae/epidemiología , Infecciones por Rhabdoviridae/virología , Genes Virales , Genoma Viral , Humanos , Lyssavirus/clasificación , Lyssavirus/genética , Lyssavirus/aislamiento & purificación , Filogenia , Taiwán/epidemiología
2.
Avian Pathol ; 39(5): 333-8, 2010 Oct.
Artículo en Inglés | MEDLINE | ID: mdl-20954009

RESUMEN

Riemerella anatipestifer is a Gram-negative bacterium that can cause disease in a wide range of wild and domesticated birds, especially waterfowl. The presence of an antibiotic-resistance gene in R. anatipestifer has not yet been reported, indicating the need for investigation. In the present study, 40.5% of R. anatipestifer isolates were found to exhibit resistance to chloramphenicol, while 45.9% showed intermediate resistance and 13.5% were susceptible to chloramphenicol, an antibiotic that has been prohibited for use in food animals in Taiwan since 2003. The resistance gene was identified as the cat gene and cloned by library sequencing. The prevalence of the cat gene in Taiwanese R. anatipestifer isolates was 78.4%. The position of the cat gene was then determined within the novel plasmid, designated pRA0511. pRA0511 was sequenced and shown to be 11,435 bp in size with 10 open reading frames (ORFs). Proteins putatively encoded by these 10 ORFs included four drug-resistance-associated proteins. Two proteins designed as chloramphenicol acetyltransferases (CATs) were encoded by two non-adjacent ORFs, and the other two were TetX2 and a multi-drug ABC transporter permease/ATPase. The putative CAT protein had 62.9 to 79.5% homology to a known type B CAT. The pRA0511 plasmid is the first identified drug-resistance plasmid in R. anatipestifer, more specifically associated with chloramphenicol resistance.


Asunto(s)
Cloranfenicol/farmacología , Patos , Infecciones por Flavobacteriaceae/veterinaria , Flavobacteriaceae/efectos de los fármacos , Gansos , Enfermedades de las Aves de Corral/microbiología , Animales , Antibacterianos/farmacología , Proteínas Bacterianas/genética , Proteínas Bacterianas/metabolismo , Secuencia de Bases , Clonación Molecular , Farmacorresistencia Bacteriana , Flavobacteriaceae/genética , Infecciones por Flavobacteriaceae/epidemiología , Infecciones por Flavobacteriaceae/microbiología , Regulación Bacteriana de la Expresión Génica/fisiología , Filogenia , Enfermedades de las Aves de Corral/epidemiología , Análisis de Secuencia de ADN , Taiwán/epidemiología
3.
Avian Dis ; 54(2): 885-93, 2010 Jun.
Artículo en Inglés | MEDLINE | ID: mdl-20608534

RESUMEN

During the surveillance of avian influenza, an H5N2 influenza A virus was isolated from a cloacal swab sample of an apparently healthy chicken in Taiwan in October 2008. It was found that the HA of the virus had a pair of dibasic amino acid residues at the cleavage site, which might be a marker of highly pathogenic avian influenza virus. However, the intravenous pathogenicity index of the isolate was 0.89, indicating that the virus was approaching high pathogenicity in chickens. Virus isolation was negative in 2916 birds from 146 farms in a 3-km radius around the farm where the virus was isolated. Genetic analysis of the eight segments of the isolate indicated that the isolated virus was a reassortant whose HA and NA gene segments belonged to the American lineage and internal genes to the Eurasian lineage.


Asunto(s)
Pollos , Subtipo H5N2 del Virus de la Influenza A/aislamiento & purificación , Gripe Aviar/virología , Animales , Hemaglutininas/genética , Subtipo H5N2 del Virus de la Influenza A/genética , Subtipo H5N2 del Virus de la Influenza A/patogenicidad , Gripe Aviar/epidemiología , Neuraminidasa/genética , Filogenia , Taiwán/epidemiología
4.
J Vet Med Sci ; 82(3): 325-332, 2020 Mar 24.
Artículo en Inglés | MEDLINE | ID: mdl-31996495

RESUMEN

Among domestic animals, melioidosis is one of the most common diseases reported in goat, sheep, and swine. To evaluate the specific antibodies in goats with melioidosis, we developed a serology test using recombinant outer membrane protein A (OmpA) and flagellin (FliC) of Burkholderia pseudomallei as antigens. DNA corresponding to each antigen was cloned into a pET32a vector and expressed in Escherichia coli. Essentially, the recombinant OmpA and FliC were expressed in a soluble form that could be isolated with 95% homogeneity. Both recombinants could be recognized by rabbit antibodies prepared against heat-inactivated B. pseudomallei (1:1,000) on a Western blot. Subsequently, we demonstrated that both recombinants could capture the antibodies present in goat with naturally occurring melioidosis (optimized titer 1:40) while not cross-reacting with the serum samples of goats naturally infected by Corynebacterium pseudotuberculosis or Staphylococcus aureus. Finally, an enzyme-linked immunosorbent assay (ELISA) using 20 goat serum samples without melioidosis and 10 goat serum samples with melioidosis demonstrated that the infected group has significantly higher antibody titer levels than the normal group (P<0.001) when using either OmpA or FliC as an antigen. However, the sensitivity (100%) of the assay using OmpA was superior to that (90%) from using FliC. Serological tests that are commonly used often rely on antigens from crude cell extracts, which pose risks for laboratory-acquired infections and inconsistency in their preparation; however, use of recombinant OmpA is safe; it can potentially be used as a reagent in testing for goat melioidosis.


Asunto(s)
Proteínas de la Membrana Bacteriana Externa/inmunología , Burkholderia pseudomallei/inmunología , Flagelina/inmunología , Enfermedades de las Cabras/diagnóstico , Melioidosis/veterinaria , Animales , Anticuerpos Antibacterianos/sangre , Ensayo de Inmunoadsorción Enzimática/veterinaria , Enfermedades de las Cabras/sangre , Cabras , Inmunoensayo , Melioidosis/diagnóstico , Melioidosis/inmunología , Proteínas Recombinantes/inmunología , Sensibilidad y Especificidad , Pruebas Serológicas/veterinaria
5.
J Vet Sci ; 20(1): 51-57, 2019 Jan 31.
Artículo en Inglés | MEDLINE | ID: mdl-30481981

RESUMEN

Monoclonal antibodies (MAbs) are widely applied in disease diagnoses. Herein, we report a MAb, WF-4, against Influenza A virus nucleoprotein (NP), its broad response with Influenza A virus, and its application in an immunohistochemistry (IHC) assay. WF-4 was screened by immunofluorescence assay (IFA). The results showed that its reactivity with baculovirus-expressed full-length recombinant NP (rNP) in Western blot (WB), indicating its IHC applicability. Fifteen Influenza A virus (reference subtypes H1 to H15) infected chicken embryonated chorioallantoic membranes (CAM), fixed by formalin, were all detectable in the WF-4-based IHC assay. Also, the reactivity of the IHC test with NP from experimentally inoculated H6N1 and from all recent outbreaks of H5 subtype avian Influenza A virus (AIV) field cases in Taiwan showed positive results. Our data indicate that CAM, a by-product of Influenza A virus preparation, is helpful for Influenza A virus-specific MAb characterization, and that the WF-4 MAb recognizes conserved and linear epitopes of Influenza A virus NP. Therefore, WF-4 is capable of detecting NP antigens via IHC and may be suitable for developing various tests for diagnosis of Influenza A virus and, especially, AIV infection.


Asunto(s)
Pollos , Inmunohistoquímica/veterinaria , Subtipo H5N2 del Virus de la Influenza A/inmunología , Virus de la Influenza A/inmunología , Proteínas de Unión al ARN/inmunología , Proteínas del Núcleo Viral/inmunología , Animales , Anticuerpos Monoclonales/inmunología , Anticuerpos Antivirales/inmunología , Membrana Corioalantoides/inmunología , Técnica del Anticuerpo Fluorescente/veterinaria , Proteínas de la Nucleocápside , Taiwán
6.
Vet Microbiol ; 127(3-4): 217-26, 2008 Mar 18.
Artículo en Inglés | MEDLINE | ID: mdl-17869456

RESUMEN

Newcastle disease (ND) and avian influenza (AI) are two of the most important zoonotic viral diseases of birds throughout the world. These two viruses often have a great impact upon the poultry industry. Both viruses are associated with transmission from wild to domestic birds, and often display similar signs that need to be differentiated. A rapid surveillance among wild and domestic birds is important for early disease detection and intervention, and is the basis for what measures should be taken. The surveillance, thus, should be able to differentiate the diseases and provide a detailed analysis of the virus strains. Here, we described a fast, simultaneous and inexpensive approach to the detection of Newcastle disease virus (NDV) and avian influenza virus (AIV) using oligonucleotide microarrays. The NDV pathotypes and the AIV haemagglutinin subtypes H5 and H7 were determined at the same time. Different probes on a microarray targeting the same gene were implemented in order to encompass the diversified virus strains or provide multiple confirmations of the genotype. This ensures good sensitivity and specificity among divergent viruses. Twenty-four virus isolates and twenty-four various combinations of the viruses were tested in this study. All viruses were successfully detected and typed. The hybridization results on microarrays were clearly identified with the naked eyes, with no further imaging equipment needed. The results demonstrate that the detection and typing of multiple viruses can be performed simultaneously and easily using oligonucleotide microarrays. The proposed method may provide potential for rapid surveillance and differential diagnosis of these two important zoonoses in both wild and domestic birds.


Asunto(s)
Virus de la Influenza A/aislamiento & purificación , Gripe Aviar/diagnóstico , Enfermedad de Newcastle/diagnóstico , Virus de la Enfermedad de Newcastle/aislamiento & purificación , Análisis de Secuencia por Matrices de Oligonucleótidos/veterinaria , Animales , Secuencia de Bases , Aves , Genoma Viral , Genotipo , Virus de la Influenza A/clasificación , Virus de la Influenza A/genética , Gripe Aviar/virología , Técnicas de Diagnóstico Molecular/métodos , Técnicas de Diagnóstico Molecular/veterinaria , Enfermedad de Newcastle/virología , Virus de la Enfermedad de Newcastle/clasificación , Virus de la Enfermedad de Newcastle/genética , Análisis de Secuencia por Matrices de Oligonucleótidos/métodos , Filogenia , Aves de Corral , Reacción en Cadena de la Polimerasa de Transcriptasa Inversa/veterinaria , Sensibilidad y Especificidad , Especificidad de la Especie
7.
J Virol Methods ; 243: 98-104, 2017 05.
Artículo en Inglés | MEDLINE | ID: mdl-28159666

RESUMEN

Caprine arthritis-encephalitis (CAE) in goats is a complex disease syndrome caused by a lentivirus. This persistent viral infection results in arthritis in adult goats and encephalitis in lambs. The prognosis for the encephalitic form is normally poor, and this form of the disease has caused substantial economic losses for goat farmers. Hence, a more efficient detection platform based on recombinase polymerase amplification (RPA) and a lateral flow dipstick (LFD) was developed in the present study for detecting the proviral DNA of caprine arthritis-encephalitis virus (CAEV). Under the optimal incubation conditions, specifically, 30min at 37°C for RPA followed by 5min at room temperature for LFD, the assay was found to be sensitive to a lower limit of 80pg of total DNA and 10 copies of plasmid DNA. Furthermore, there was no cross-reaction with other tested viruses, including goat pox virus and bovine leukemia virus. Given its simplicity and portability, this RPA-LFD protocol can serve as an alternative tool to ELISA for the primary screening of CAEV, one that is suitable for both laboratory and field application. When the RPA-LFD was applied in parallel with serological ELISA for the detection of CAEV in field samples, the RPA-LFD assay exhibited a higher sensitivity than the traditional method, and 82% of the 200 samples collected in Taiwan were found to be positive. To our knowledge, this is the first report providing evidence to support the use of an RPA-LFD assay as a specific and sensitive platform for detecting CAEV proviral DNA in goats in a faster manner, one that is also applicable for on-site utilization at farms and that should be useful in both eradication programs and epidemiological studies.


Asunto(s)
Virus de la Artritis-Encefalitis Caprina/aislamiento & purificación , Cromatografía/métodos , Enfermedades de las Cabras/diagnóstico , Enfermedades de las Cabras/virología , Infecciones por Lentivirus/veterinaria , Técnicas de Amplificación de Ácido Nucleico/métodos , Sistemas de Atención de Punto , Animales , Virus de la Artritis-Encefalitis Caprina/genética , ADN Viral/genética , ADN Viral/aislamiento & purificación , Cabras , Infecciones por Lentivirus/diagnóstico , Provirus/genética , Recombinasas/metabolismo , Sensibilidad y Especificidad , Taiwán , Temperatura
8.
PLoS One ; 12(10): e0184831, 2017.
Artículo en Inglés | MEDLINE | ID: mdl-28977009

RESUMEN

Since 2013, rabies cases have been reported among Formosan ferret badgers in Taiwan, and they have been shown to be the major reservoirs for Taiwanese enzootics. To control and eradicate rabies, the authorities plan to implement a vaccination programme. Before distributing live vaccines in the field, this study assessed the safety, efficacy, and immunogenicity of SAG2 vaccine on ferret badgers by direct oral instillation. After application of 109 TCID50/dose, no virus was excreted into the oral cavity 1-7 days post-application, and safety was also satisfactorily verified over a 266-day period. Moreover, despite the low level of rabies virus neutralising antibodies induced after vaccination of a 108 TCID50/dose, the efficacy assessment revealed a 100% survival rate (15/15) of vaccinees and an 87.5% fatality rate (7/8) in control animals after a challenge on the 198th day post-vaccination. The immunisation and protection rates obtained more than 6 months after a single vaccination dose demonstrated that SAG2 is an ideal vaccine candidate to protect Formosan ferret badgers against rabies in Taiwan.


Asunto(s)
Hurones/inmunología , Vacunas Antirrábicas/inmunología , Rabia/prevención & control , Vacunación , Administración Oral , Animales , Reservorios de Enfermedades , Vacunas Antirrábicas/administración & dosificación , Vacunas Antirrábicas/efectos adversos , Taiwán
9.
J Virol Methods ; 220: 39-42, 2015 Aug.
Artículo en Inglés | MEDLINE | ID: mdl-25896189

RESUMEN

The H5 avian influenza virus subtype has huge impact on the poultry industry. Rapid diagnosis and accurate identification of the highly pathogenic avian influenza virus and low-pathogenicity avian influenza virus is essential, especially during H5 outbreaks and surveillance. To this end, a novel and rapid strategy for H5 virus molecular pathotyping is presented. The specific hemagglutinin gene of the H5 virus and the basic amino acid number of the motif at the hemagglutinin precursor protein cleavage site were detected using oligonucleotide microarray. Highly pathogenic and low-pathogenicity avian influenza viruses in Taiwan were differentiated using 13 microarray probes with the naked eye. The detection limit reached 3.4 viral RNA copies, 1000 times more sensitive than reverse transcription polymerase chain reaction. Thus, the oligonucleotide microarray would provide an alternative H5 pathogenicity determination using the naked eye for laboratories lacking facilities.


Asunto(s)
Glicoproteínas Hemaglutininas del Virus de la Influenza/genética , Virus de la Influenza A/clasificación , Virus de la Influenza A/aislamiento & purificación , Gripe Aviar/virología , Análisis de Secuencia por Matrices de Oligonucleótidos/métodos , Animales , Virus de la Influenza A/genética , Virus de la Influenza A/patogenicidad , Aves de Corral , Sensibilidad y Especificidad , Taiwán
10.
J Wildl Dis ; 51(4): 923-8, 2015 Oct.
Artículo en Inglés | MEDLINE | ID: mdl-26267459

RESUMEN

Fifteen ferret badgers (Melogale moschata subaurantiaca), collected 2010-13 and stored frozen, were submitted for rabies diagnosis by direct fluorescent antibody test and reverse transcription PCR. We detected seven positive animal samples, including some from 2010, which indicated that the ferret badger population in Taiwan had been affected by rabies prior to 2010.


Asunto(s)
Rabia/veterinaria , Animales , Carnívoros , Filogenia , Rabia/epidemiología , Virus de la Rabia/genética , Virus de la Rabia/aislamiento & purificación , Estudios Retrospectivos , Taiwán/epidemiología
11.
Vet Microbiol ; 84(4): 317-26, 2002 Feb 04.
Artículo en Inglés | MEDLINE | ID: mdl-11750140

RESUMEN

The O/Taiwan/99 foot-and-mouth disease virus (FMDV), a South Asian topotype of serotype O, was introduced into Taiwan in 1999. The Chinese yellow cattle infected by the virus did not develop clinical lesions under experimental and field conditions. A blocking enzyme-linked immunosorbent assay (ELISA) kit with the 3AB antigen, a polypeptide of FMDV non-structural (NS) proteins, was used to evaluate the development and duration of anti-3AB antibodies, proving active viral replication, in the Chinese yellow cattle. The specificity of the assay was 99%, as was established with negative sera from regularly vaccinated and from naïve cattle. The sensitivity tested with sera from naturally infected animals was approximately 64% and it was lower than that obtained by serum neutralization (SN) test. Under experimental infection, the Chinese yellow cattle developed lower anti-3AB antibodies than that developed in other species. Duration of anti-3AB antibodies was traced in two herds of naturally infected animals, indicating that anti-3AB antibodies persisted for approximately 6 months after outbreaks. On the basis of this study, we propose that the Chinese yellow cattle may have natural resistance, which limits viral replication and reduces the development of anti-3AB antibodies.


Asunto(s)
Anticuerpos Antivirales/sangre , Enfermedades de los Bovinos/inmunología , Virus de la Fiebre Aftosa/inmunología , Fiebre Aftosa/inmunología , Proteínas no Estructurales Virales/inmunología , Animales , Anticuerpos Antivirales/inmunología , Anticuerpos Antivirales/aislamiento & purificación , Antígenos Virales/inmunología , Bovinos , Enfermedades de los Bovinos/diagnóstico , Enfermedades de los Bovinos/virología , Ensayo de Inmunoadsorción Enzimática/métodos , Ensayo de Inmunoadsorción Enzimática/veterinaria , Fiebre Aftosa/diagnóstico , Fiebre Aftosa/virología , Enfermedades de las Cabras/inmunología , Enfermedades de las Cabras/virología , Cabras , Inmunidad Innata , Pruebas de Neutralización/veterinaria , Sensibilidad y Especificidad , Factores de Tiempo , Replicación Viral
12.
J Vet Med Sci ; 66(7): 855-9, 2004 Jul.
Artículo en Inglés | MEDLINE | ID: mdl-15297759

RESUMEN

It has been shown that certain slow neurological diseases such as bovine spongiform encephalopathy (also known as "mad cow" disease) could be transmitted through contaminated food intake by animals; therefore, the examination of meat components in commercial feeds is important for the control of the disease in public health. The combination of polymerase chain reaction-restriction fragment length polymorphisms (PCR-RFLPs) technique was applied to examine the meat components in dog and cat commercial feeds. The partial nucleotide sequence (359 bp) of animal mitochondrial cytochrome b (cytb, CYT) gene was amplified by PCR and then digested with restriction enzyme Alu I or Mbo I. In this work, eight brands of commercial dog and cat feeds available in Taiwan were examined. All brands of dog feeds that were tested contained meat from four different animals (cattle, pig, goat and chicken). In cat feeds, the chicken meat was found in five out of eight brands.


Asunto(s)
Alimentación Animal/análisis , Productos de la Carne/análisis , Animales , Gatos , Bovinos , Pollos , Citocromos b/genética , ADN/aislamiento & purificación , Enzimas de Restricción del ADN , Perros , Electroforesis en Gel de Agar , Cabras , Mitocondrias/enzimología , Reacción en Cadena de la Polimerasa/métodos , Polimorfismo de Longitud del Fragmento de Restricción , Análisis de Secuencia de ADN , Porcinos , Taiwán
13.
Vet Microbiol ; 173(3-4): 241-8, 2014 Oct 10.
Artículo en Inglés | MEDLINE | ID: mdl-25175802

RESUMEN

Bovine ephemeral fever is an arthropod-borne bovine viral disease caused by infection with bovine ephemeral fever virus which belongs to genus Ephemerovirus within the family Rhabdoviridae. In this study, serological data and virological information about the disease and the virus, spanning from 2001 to 2013, were employed to analyze the relationships of bovine ephemeral fever epizootics to population immunity and virus variation. National and regional surveillance data indicated that 2 of the 3 major epizootics and 87% regional outbreaks were associated with lower neutralizing antibody titers and immunity coverage, reflecting the importance of population immunity for the control of bovine ephemeral fever. Phylogenetic analysis and sequence comparison demonstrated that Taiwanese bovine ephemeral fever viruses were >96.0% and >97.6% similar to the East Asian isolates in nucleotide and amino acid sequences, respectively. These analyses supported that the Taiwanese viruses shared the same gene pool with the strains of the other East Asian countries, mainly Japan.


Asunto(s)
Brotes de Enfermedades/veterinaria , Virus de la Fiebre Efímera Bovina/genética , Virus de la Fiebre Efímera Bovina/inmunología , Fiebre Efímera/epidemiología , Fiebre Efímera/inmunología , Variación Genética , Inmunidad Colectiva/inmunología , Secuencia de Aminoácidos , Animales , Secuencia de Bases , Bovinos , Análisis por Conglomerados , Cartilla de ADN/genética , Fiebre Efímera/virología , Monitoreo Epidemiológico/veterinaria , Datos de Secuencia Molecular , Filogenia , Prevalencia , Reacción en Cadena de la Polimerasa de Transcriptasa Inversa/veterinaria , Análisis de Secuencia de ADN/veterinaria , Homología de Secuencia , Taiwán/epidemiología
14.
Res Vet Sci ; 94(3): 789-95, 2013 Jun.
Artículo en Inglés | MEDLINE | ID: mdl-23260863

RESUMEN

Porcine circovirus type 2 (PCV2) is the major causative agent of postweaning multisystemic wasting syndrome (PMWS) in Taiwanese pig farms. We analyzed the complete genomes of 571 Taiwanese PCV2 isolates in Taiwan from 2001 to 2011 and divided the isolates into 2 distinct genotypes (PCV2a and PCV2b) with 6 clusters (1A, 1B, 1C, 2B, 2D, and 2E). Of the 571 Taiwanese PCV2 isolates, 22.9% (131/571) belonged to PCV2a and 77.1% (440/571) to PCV2b. In this study, PCV2a isolates were the most common in 2001, and then PCV2b isolates became predominate thereafter and widely distributed in pig farms since 2003. Sequence comparisons among the 571 isolates indicated that 89.6-100% had nucleotide identity for complete genome and 87.3-100% for open reading frames 2 (ORF2). The results suggest that a higher genetic variation and shift occurred among PCV2 isolates collected from 2001 to 2011 in Taiwan.


Asunto(s)
Infecciones por Circoviridae/veterinaria , Circovirus/genética , Enfermedades de los Porcinos/virología , Secuencia de Aminoácidos , Animales , Secuencia de Bases , Infecciones por Circoviridae/epidemiología , Infecciones por Circoviridae/virología , Circovirus/aislamiento & purificación , ADN Viral/genética , ADN Viral/aislamiento & purificación , Variación Genética/genética , Genoma Viral/genética , Genotipo , Datos de Secuencia Molecular , Sistemas de Lectura Abierta/genética , Filogenia , Reacción en Cadena de la Polimerasa/veterinaria , Prevalencia , Selección Genética/genética , Porcinos/virología , Enfermedades de los Porcinos/epidemiología , Taiwán/epidemiología
15.
Vet Microbiol ; 154(3-4): 325-31, 2012 Jan 27.
Artículo en Inglés | MEDLINE | ID: mdl-21820820

RESUMEN

The cat gene, coding for chloramphenicol acetyltransferase has been reported for conferring the chloramphenicol resistance for Riemerella anatipestifer. Chloramphenicol acetyltransferases, however, are unable to inactivate florfenicol. In this study, 66 R. anatipestifer isolates were investigated for their susceptibility to chloramphenicol and florfenicol and the presence of floR gene. Results showed nine florfenicol intermediate or resistant R. anatipestifer isolates were all floR positive. The expression of floR gene in E. coli and inhibition studies with PAßN indicated that the floR gene was as an efflux pump conferring resistance to both chloramphenicol and florfenicol. Southern hybridization revealed the floR was located in the plasmid DNA of five isolates and in the chromosomal DNA of four isolates. Furthermore, two novel floR-carrying plasmids designated pRA0726 and pRA0846 were sequenced completely. pRA0726 was 11,704 bp in size with 10 putative open reading frames which included the floR, catB and bla(OXA-209) resistance genes. The most differences between sequences of pRA0846 and pRA0726 were the absence of a bla(OXA-209) gene and the deletion of 321 nucleotides of orf1 in pRA0846. Plasmid curing tests demonstrated that pRA0726 carried functional coding proteins for resistance to phenicol and ß-lactam antimicrobials. To the best of our knowledge, this is the first report of presence of the floR and bla(OXA-209) resistance genes in R. anatipestifer.


Asunto(s)
Antibacterianos/farmacología , Resistencia al Cloranfenicol/genética , Patos/microbiología , Gansos/microbiología , Riemerella/fisiología , Tianfenicol/análogos & derivados , Animales , Gatos , Cloranfenicol O-Acetiltransferasa/genética , Genes Bacterianos/efectos de los fármacos , Riemerella/genética , Tianfenicol/farmacología
16.
J Vet Med Sci ; 73(6): 767-72, 2011 Jun.
Artículo en Inglés | MEDLINE | ID: mdl-21301183

RESUMEN

H5N2 viruses were isolated from cloacal swab samples of apparently healthy chickens in Taiwan in 2003 and 2008 during surveillance of avian influenza. Each of the viruses was eradicated by stamping out. The official diagnosis report indicated that the Intravenous Pathogenicity Indexes (IVPIs) of the isolates were 0.00 and 0.89, respectively, indicating that these were low pathogenic strains, although the hemagglutinin of the strain isolated in 2008 (Taiwan08) had multibasic amino acid residues at the cleavage site (PQRKKR/G). In the present study, these H5N2 viruses were assessed for their intravenous and intranasal pathogenicity for chickens. It was examined whether Taiwan08 acquires pathogenicity through consecutive passages in chickens. Intravenous pathogenicity of Taiwan08 depended upon the age of the chickens used for the IVPI test; all of the eight-week-old chickens intravenously inoculated with Taiwan08 showed clinical signs but survived for ten days post inoculation (IVPI=0.68), whereas all the six-week-old chickens died (IVPI=1.86). Taiwan08-P8, which were passaged in chickens for eight times, killed all the eight-week-old chickens (IVPI=2.36). The four-week-old chickens died after intranasal inoculation of Taiwan08-P8, indicating that Taiwan08 must have become highly pathogenic during circulation in chicken flocks. These results emphasize the importance of a stamping out policy for avian influenza even if the IVPI of the causal virus is low.


Asunto(s)
Pollos , Subtipo H5N1 del Virus de la Influenza A/patogenicidad , Gripe Aviar/virología , Factores de Edad , Secuencia de Aminoácidos , Animales , Anticuerpos Antivirales/sangre , Genoma Viral , Subtipo H5N1 del Virus de la Influenza A/genética , Gripe Aviar/genética , Mutación , ARN Viral/química , ARN Viral/genética , Reacción en Cadena de la Polimerasa de Transcriptasa Inversa/veterinaria , Taiwán , Virulencia
17.
Vet J ; 183(2): 184-90, 2010 Feb.
Artículo en Inglés | MEDLINE | ID: mdl-19010700

RESUMEN

Canine distemper (CD) is a highly contagious disease with a worldwide distribution. Genetic diversity in genes encoding the haemagglutinin (H) and fusion (F) virus envelope proteins have been implicated in the increasing incidence of CD. Unlike the H gene, little is known about the genetic variability of the F gene in this virus. In the present study sequence analysis of the complete coding region of the F protein from CD virus isolates from Taiwan were carried out. Phylogenetic analysis demonstrated that the majority of isolates were similar to those found in neighbouring China and Japan, but were genetically distinct from vaccine strains. Remarkable variations were found scattered throughout the pre-peptide region (residues 1-135). The sequence identity of this region between locally sourced strains and between these strains and vaccine strains was 89% and 64 to 67%, respectively. Analysis suggested a novel strain of distant genetic lineage was present in dogs in the geographically isolated city of Hualien.


Asunto(s)
Virus del Moquillo Canino/genética , Moquillo/virología , Variación Genética , Proteínas Virales de Fusión/genética , Secuencia de Aminoácidos , Animales , Secuencia de Bases , ADN Viral/química , ADN Viral/genética , Virus del Moquillo Canino/clasificación , Perros , Datos de Secuencia Molecular , Filogenia , Alineación de Secuencia
18.
Virology ; 383(2): 338-47, 2009 Jan 20.
Artículo en Inglés | MEDLINE | ID: mdl-19012942

RESUMEN

Porcine circovirus 2 (PCV2), open reading frame 3 (ORF3) codes a 105 amino acid protein that causes apoptosis of PCV2 infected cells. In infected cells, the ORF3 causes the accumulation of p53 by interacting with pPirh2 and possibly by disrupting the association of p53 and pPirh2 (J.Virol.81(2007)9560). Mutant PCV2 lacking the expression of ORF3 are infectious and replicate in cells in vitro, but do not cause apoptosis of the infected cells. The ORF3 of PCV2 has been shown to be involved in pathogenesis of the virus in mice model (J. Virol. 80(2006)5065). Here we report the experimental inoculation of ORF3 deficient PCV2 in its natural host, the piglets. The pathogenicity of the ORF3 deficient virus is attenuated in the piglets. The mutant virus did not cause any observable disease or perturbation of the lymphocyte count in the inoculated piglets and elicited an efficient immune response. When compared with the wildtype virus infection, the mutant virus infection was characterized by mild viremia and absence of pathological lesions. The findings highlight the role of ORF3 in the pathogenesis of PCV2 infection in its host.


Asunto(s)
Infecciones por Circoviridae/veterinaria , Circovirus/patogenicidad , Enfermedades de los Porcinos/virología , Proteínas Virales/fisiología , Factores de Virulencia/fisiología , Animales , Anticuerpos Antivirales/sangre , Linfocitos T CD4-Positivos/inmunología , Linfocitos T CD8-positivos/inmunología , Línea Celular , Infecciones por Circoviridae/inmunología , Circovirus/genética , Circovirus/inmunología , Eliminación de Gen , Recuento de Linfocitos , Índice de Severidad de la Enfermedad , Porcinos , Enfermedades de los Porcinos/inmunología , Proteínas Virales/genética , Viremia , Factores de Virulencia/genética
19.
Virus Genes ; 35(3): 705-12, 2007 Dec.
Artículo en Inglés | MEDLINE | ID: mdl-17682935

RESUMEN

An outbreak of contagious ecthyma in goats in central Taiwan was investigated. The disease was diagnosed by physical and histopathologic examinations, and the etiology of the disease was identified as orf virus by electron microscopy and polymerase chain reaction (PCR) and sequence of major envelope protein (B2L) gene. The entire protein-coding region of B2L gene were cloned and sequenced. Phylogenetic analysis of B2L amino acid sequences showed that the orf virus identified in this outbreak was closer to the Indian ORFV-Mukteswar 59/05 isolate. This is the first report on the molecular characterization of orf virus in Taiwan.


Asunto(s)
Brotes de Enfermedades , Ectima Contagioso/epidemiología , Ectima Contagioso/virología , Virus del Orf/aislamiento & purificación , Animales , ADN Viral/química , ADN Viral/genética , ADN Viral/aislamiento & purificación , Ectima Contagioso/patología , Ectima Contagioso/fisiopatología , Cabras , Microscopía Electrónica de Transmisión , Datos de Secuencia Molecular , Virus del Orf/genética , Virus del Orf/ultraestructura , Filogenia , Reacción en Cadena de la Polimerasa , Análisis de Secuencia de ADN , Homología de Secuencia de Aminoácido , Taiwán/epidemiología , Proteínas del Envoltorio Viral/genética , Virión/ultraestructura
20.
J Med Virol ; 73(3): 419-31, 2004 Jul.
Artículo en Inglés | MEDLINE | ID: mdl-15170638

RESUMEN

Activation and expansion of dengue virus-specific T cells and abnormal liver functions in dengue patients have been documented. However, it remains to be determined whether T cells are involved in the pathogenic mechanism of dengue virus infection. In this study, immunocompetent C57BL/6 mice were employed to study dengue virus-induced T cell activation. Mice were inoculated with 10(8) PFU dengue virus serotype 2 strain 16681 by the intravenous route. Dengue viral core RNA was detected by RT-PCR in mouse serum, liver, spleen, and brain at different time points after infection. Splenic T cells were activated as evidenced by their expression of CD69 and O-glycosylated CD43 at as early as day 3 after infection. Splenic T cell expression of O-glycosylated CD43 and IFN-gamma production coordinately peaked at day 5. Coincided with the peak of splenic T cell activation was hepatic lymphocyte infiltration and elevation of liver enzymes. Flow cytometric analysis revealed the infiltrating CD8(+) T cell to CD4(+) T cell ratio was 5/3. After a second inoculation of dengue virus, hepatic T cell infiltration and liver enzyme levels increased sharply. The infiltrating hepatic CD8(+) T cell to CD4(+) T cell ratio increased to 5.8/1. A strong correlation was found between T cell activation and hepatic cellular infiltration in immunocompetent mice infected with dengue virus. The kinetics of liver enzyme elevation also correlated with that of T cell activation. These data suggest a relationship between T cell infiltration and elevation of liver enzymes.


Asunto(s)
Virus del Dengue/patogenicidad , Dengue/inmunología , Dengue/patología , Hígado/patología , Activación de Linfocitos , Linfocitos T/inmunología , Alanina Transaminasa/sangre , Animales , Antígenos CD/análisis , Antígenos de Diferenciación de Linfocitos T/análisis , Aspartato Aminotransferasas/sangre , Encéfalo/virología , Relación CD4-CD8 , Inmunocompetencia , Interferón gamma/análisis , Lectinas Tipo C , Leucosialina , Hígado/enzimología , Hígado/inmunología , Hígado/virología , Pruebas de Función Hepática , Ratones , Ratones Endogámicos C57BL , ARN Viral/sangre , Sialoglicoproteínas/análisis , Bazo/virología
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