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This study aimed to investigate the prevalence of viral agents causing reproductive failure in pigs in Korea. In addition, two types of multiplex real-time PCR (mqPCR) were developed for the simultaneous detection of Aujeszky's disease virus (ADV) and porcine parvovirus (PPV) in mqPCR and encephalomyocarditis virus (EMCV) and Japanese encephalitis virus (JEV) in reverse transcription mqPCR (mRT-qPCR). A total of 150 aborted fetus samples collected from 2020 to 2022 were analyzed. Porcine reproductive and respiratory syndrome virus was the most prevalent (49/150 32.7%), followed by porcine circovirus type 2 (31/150, 20.7%), and PPV1 (7/150, 4.7%), whereas ADV, EMCV, and JEV were not detected. The newly developed mqPCR and mRT-qPCR could simultaneously detect and differentiate with high sensitivities and specificities. When applied to aborted fetuses, the newly developed mqPCR for PPV was 33.3% more sensitivities than the previously established diagnostic method. Amino acid analysis of the VP2 sequences of PPV isolates revealed considerable similarity to the highly pathogenic Kresse strain. This study successfully evaluated the prevalence of viral agents causing reproductive failure among swine in Korea, the developed mqPCR and mRT-qPCR methods could be utilized as effective and accurate diagnostic methods for the epidemiological surveillance of ADV, PPV, EMCV, and JEV.
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Reacción en Cadena de la Polimerasa Multiplex , Enfermedades de los Porcinos , Animales , Porcinos , República de Corea/epidemiología , Enfermedades de los Porcinos/virología , Enfermedades de los Porcinos/diagnóstico , Enfermedades de los Porcinos/epidemiología , Reacción en Cadena de la Polimerasa Multiplex/métodos , Reacción en Cadena en Tiempo Real de la Polimerasa/métodos , Prevalencia , Femenino , Reacción en Cadena de la Polimerasa de Transcriptasa Inversa/métodos , Embarazo , Parvovirus Porcino/genética , Parvovirus Porcino/aislamiento & purificación , Aborto Veterinario/virología , Aborto Veterinario/epidemiología , Virosis/diagnóstico , Virosis/epidemiología , Virosis/virologíaRESUMEN
OBJECTIVES: Clostridioides difficile is an etiological agent of enteric diseases in humans and animals. Animals are considered a potential reservoir due to the genetic and antimicrobial resistance similarities between human and animal C. difficile isolates. In this study, we evaluated the genetic characteristics and antimicrobial resistance profiles of C. difficile isolated from 942 fecal samples collected from horses in South Korea during 2019-2020. METHODS: The C. difficile isolates were tested for toxin genes including tcdA (A), tcdB (B), and cdtAB (CDT) and deletions of the tcdC gene by PCR. In addition, ribotyping, multilocus sequence typing, and antimicrobial susceptibility tests were performed. RESULTS: Twenty-three (2.4%) C. difficile isolates were associated with diarrhea in foals under 1 year old during the spring-summer period. Of these, 82.6% were toxigenic strains, determined to be A+B+CDT+ (52.1%) or A+B+CDTâ (30.4%). All isolates were susceptible to metronidazole and vancomycin, and resistant to cefotaxime and gentamicin, and 76.2% were multidrug resistant (MDR). RT078/ST11/Clade 5 was the most common genotype (47.8%), which was also found in animals and humans worldwide. All RT078/ST11/Clade 5 strains were toxigenic and had deletions of the tcdC gene. About half of these strains were resistant to moxifloxacin, and 63.6% were MDR. CONCLUSIONS: C. difficile isolates in this study consisted mostly of toxigenic and MDR strains, and their genetic properties were highly similar to human C. difficile isolates. These results suggest high possibilities of zoonotic transmission and can provide knowledge for establishing strategies for the treatment and prevention of C. difficile infection.
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Toxinas Bacterianas , Clostridioides difficile , Infecciones por Clostridium , Farmacorresistencia Bacteriana , Animales , Antibacterianos/farmacología , Toxinas Bacterianas/genética , Clostridioides difficile/efectos de los fármacos , Clostridioides difficile/genética , Infecciones por Clostridium/epidemiología , Infecciones por Clostridium/microbiología , Infecciones por Clostridium/veterinaria , Farmacorresistencia Bacteriana/genética , Caballos , Pruebas de Sensibilidad Microbiana , Prevalencia , República de Corea/epidemiología , RibotipificaciónRESUMEN
BACKGROUND: Porcine reproductive and respiratory syndrome virus (PRRSV) has caused huge economic losses in the global swine industry. Frequent genetic variations in this virus cause difficulties in controlling and accurately diagnosing PRRSV. METHODS: In this study, we investigated the genetic characteristics of PRRSV-1 and PRRSV-2 circulating in Korea from January 2018 to September 2021 and evaluated three one-step real-time reverse transcription polymerase chain reaction (RT-PCR) assays. RESULTS: A total of 129 lung samples were collected, consisting of 47 samples for PRRSV-1, 62 samples for PRRSV-2, and 20 PRRSV-negative samples. Nucleotide sequence analysis of open reading frames (ORFs) 5, ORF6, and ORF7 genes from PRRSV samples showed that PRRSV-1 belonged to subgroup A (43/47, 91.49%) and subgroup C (4/47, 8.51%), whereas PRRSV-2 was classified as lineage 1 (25/62, 40.32%), Korean lineage (Kor) C (13/62, 20.97%), Kor B (10/62, 16.13%), lineage 5 (9/62, 14.52%), and Kor A (5/62, 8.06%). Amino acid sequence analysis showed that the neutralizing epitope and T cell epitope of PRRSV-1, and the decoy epitope region and hypervariable regions of PRRSV-2 had evolved under positive selection pressure. In particular, the key amino acid substitutions were found at positions 102 and 104 of glycoprotein 5 (GP5) in some PRRSV-2, and at positions 10 and 70 of membrane protein (M) in most PRRSV-2. In addition, one-step real-time RT-PCR assays, comprising two commercial tests and one test recommended by the World Organization for Animal Health (OIE), were evaluated. CONCLUSION: The results revealed that two of the real-time RT-PCR assays had high sensitivities and specificities, whereas the real-time RT-PCR assay of the OIE had low sensitivity due to mismatches between nucleotides of Korean PRRSVs and forward primers. In this study, we genetically characterized recent PRRSV occurrences and evaluated three one-step real-time RT-PCR assays used in Korea.
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Síndrome Respiratorio y de la Reproducción Porcina , Virus del Síndrome Respiratorio y Reproductivo Porcino , Enfermedades de los Porcinos , Animales , Epítopos , Variación Genética , Filogenia , Síndrome Respiratorio y de la Reproducción Porcina/diagnóstico , Virus del Síndrome Respiratorio y Reproductivo Porcino/genética , República de Corea , Reacción en Cadena de la Polimerasa de Transcriptasa Inversa/veterinaria , PorcinosRESUMEN
For serodiagnosis of foot-and-mouth disease virus (FMDV), monoclonal antibody (MAb)-based competitive ELISA (cELISA) is commonly used since it allows simple and reproducible detection of antibody response to FMDV. However, the use of mouse-origin MAb as a detection reagent is questionable, as antibody responses to FMDV in mice may differ in epitope structure and preference from those in natural hosts such as cattle and pigs. To take advantage of natural host-derived antibodies, a phage-displayed scFv library was constructed from FMDV-immune cattle and subjected to two separate pannings against inactivated FMDV type O and A. Subsequent ELISA screening revealed high-affinity scFv antibodies specific to a serotype (O or A) as well as those with pan-serotype specificity. When BvO17, an scFv antibody specific to FMDV type O, was tested as a detection reagent in cELISA, it successfully detected FMDV type O antibodies for both serum samples from vaccinated cattle and virus-challenged pigs with even higher sensitivity than a mouse MAb-based commercial FMDV type O antibody detection kit. These results demonstrate the feasibility of using natural host-derived antibodies such as bovine scFv instead of mouse MAb in cELISA for serological detection of antibody response to FMDV in the susceptible animals.
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Anticuerpos Antivirales/análisis , Virus de la Fiebre Aftosa/inmunología , Fiebre Aftosa/diagnóstico , Animales , Bacteriófagos , Bovinos , Ensayo de Inmunoadsorción Enzimática , Pruebas SerológicasRESUMEN
Bovine abortion is a critical problem in the cattle industry. Identifying causes of abortion is key to establishing appropriate herd management and prevention strategies. We used pathology examinations, detection of etiologic agents, and serology to determine the cause of bovine abortions in Korea. We analyzed 360 abortion and stillbirth cases submitted to the Animal and Plant Quarantine Agency from December 2014 to January 2020. The putative cause of abortion was identified in 140 of 360 (38.9%) cases; 124 of the 140 (88.6%) cases were attributed to infections. The most common etiologic agents detected were bovine viral diarrhea virus (65 of 360; 18.1%), Coxiella burnetii (19 of 360; 5.3%), Leptospira spp. (13 of 360; 3.6%), Listeria monocytogenes (9 of 360; 2.5%), and Neospora caninum (8 of 360; 2.2%). Minor abortifacient pathogens included Brucella abortus (2 of 360; 0.6%), bovine alphaherpesvirus 1 (2 of 360; 0.6%), Akabane virus (2 of 360, 0.6%), and bovine ephemeral fever virus (1 of 360; 0.3%). Non-infectious conditions included congenital anomalies (7 of 360; 1.9%), goiter (7 of 360; 1.9%), and vitamin A deficiency (2 of 360; 0.6%). Our diagnostic rate in cases with placenta submitted (42 of 86; 48.8%) was significantly higher than in cases without placenta (98 of 274; 35.8%), which highlights the value of submitting placentas. Our results confirm the status of the large variety of causative agents associated with abortions in cattle in Korea.
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Aborto Veterinario , Enfermedades de los Bovinos , Mortinato , Animales , Bovinos , Aborto Veterinario/virología , Aborto Veterinario/microbiología , Aborto Veterinario/epidemiología , República de Corea/epidemiología , Femenino , Mortinato/veterinaria , Mortinato/epidemiología , Enfermedades de los Bovinos/epidemiología , Enfermedades de los Bovinos/virología , Enfermedades de los Bovinos/microbiología , EmbarazoRESUMEN
Two 3-month-old goats (Capra aegagrus hircus and C. hircus coreanae) died after ataxia. In both goats, white nodules 3 mm in diameter were scattered from the duodenum to the ileum and well-raised white nodules 2-3 mm-diameter in the mucosa of the small intestine. Histopathologically, numerous mucosal polyps with coccidial oocysts were observed in the small intestine and several schizonts, macrogametocytes, microgametocytes, and macrogametes were observed in mucosal polyps in the jejunum. Based on fecal flotation tests, the oocysts morphologically resembled those of Eimeria christenseni and E. sundarbanensis; however, their sizes were different. The 18S rRNA gene and COI were phylogenetically analyzed for the molecular identification and characterization of Eimeria sp. Based on 18S rRNA gene similarity, the isolates formed an independent cluster within the related goat Eimeria clade, and the closest species were E. christenseni C2_42, E. hirci C2_99, and E. arloingi C2_119. Furthermore, these were also distinguished from other related goat Eimeria spp. in the phylogenetic tree based on the COI gene. Considering all histopathological, morphological, and phylogenetic analyses, the current study was diagnosed as fatal coccidiosis due to heavy infection with an unrecorded Eimeria species. Thus, we report in this study with caution regarding coccidiosis caused by an unrecorded Eimeria.
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Coccidiosis , Eimeria , Animales , Eimeria/genética , Filogenia , Cabras , Coccidiosis/veterinaria , Oocistos , ARN Ribosómico 18S/genéticaRESUMEN
This study aimed to investigate the pathogenicity of extraintestinal pathogenic Escherichia coli (ExPEC) isolated from dog and cat lung samples in South Korea. A total of 101 E. coli isolates were analyzed for virulence factors, phylogroups, and O-serogroups, and their correlation with bacterial pneumonia-induced mortality was elucidated. P fimbriae structural subunit (papA), hemolysin D (hlyD), and cytotoxic necrotizing factor 1 (cnf1) were highly prevalent in both species, indicating correlation with bacterial pneumonia. Phylogroups B1 and B2 were the most prevalent phylogroups (36.6% and 32.7%, respectively) and associated with high bacterial pneumonia-induced mortality rates. Isolates from both species belonging to phylogroup B2 showed high frequency of papA, hlyD, and cnf1. O-serogrouping revealed 21 and 15 serogroups in dogs and cats, respectively. In dogs, O88 was the most prevalent serogroup (n = 8), and the frequency of virulence factors was high for O4 and O6. In cats, O4 was the most prevalent serogroup (n = 6), and the frequency of virulence factors was high for O4 and O6. O4 and O6 serogroups were mainly grouped under phylogroup B2 and associated with high bacterial pneumonia-induced mortality. This study characterized the pathogenicity of ExPEC and described the probability of ExPEC pneumonia-induced mortality.
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Enfermedades de los Gatos , Enfermedades de los Perros , Infecciones por Escherichia coli , Escherichia coli Patógena Extraintestinal , Gatos , Perros , Animales , Escherichia coli , Virulencia , Enfermedades de los Gatos/microbiología , Infecciones por Escherichia coli/microbiología , Enfermedades de los Perros/microbiología , Factores de Virulencia , Pulmón , FilogeniaRESUMEN
Introduction: Cryptosporidium, Cystoisospora, and Giardia duodenalis are gastrointestinal protozoa parasites that cause diarrhea in various animals. However, information regarding the detection and phylogenetic characterization of gastrointestinal protozoa parasites in cats is limited throughout South Korea. Therefore, this study aimed to determine the detection and identify subspecies of gastrointestinal protozoa parasites in cats from South Korea. Methods: A total of 290 fecal samples were collected from stray, companion, and shelter cats in six provinces. Cryptosporidium, Cystoisospora, and G. duodenalis were identified by PCR. All positive samples were subtyped by PCR and sequencing of gp60, ITS-1, tpi, bg, and gdh. Results: The overall detection of gastrointestinal protozoan parasitic infection was 17.93%. G. duodenalis was the most prevalent, with 7.93%, followed by Cystoisospora spp. (7.24%) and Cryptosporidium spp. (4.48%). In addition, C. felis (n=10), C. parvum (n=2), C. ryanae (n=1), Cystoisospora felis (n=14), Cystoisospora suis (n=5), Cystoisospora ohioensis (n=1), Cystoisospora spp. were identified in subspecies analysis of positive samples. C. felis showed a significant association with diarrhea (7.81%) and living condition (6.04%), and Cystoisospora felis in diarreha (9.38%) according to detection. Through phylogenetic analysis of the tpi, bg, and gdh genes from 23 G. duodenalispositive samples, it was confirmed that the samples of present study belonged to assemblage A, B, C, and D. Discussion: South Korean cats have a high rate of gastrointestinal protozoan parasites infection with cat-specific Cryptosporidium and Cystoisospora, which are associated with living conditions and diarrhea symptoms. Moreover, zoonotic and other animal-specific subtype of protozoan parasites have been detected in cat feces.
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Criptosporidiosis , Cryptosporidium , Felis , Giardia lamblia , Giardiasis , Parasitosis Intestinales , Parásitos , Gatos , Animales , Giardia lamblia/genética , Cryptosporidium/genética , Criptosporidiosis/epidemiología , Criptosporidiosis/parasitología , Giardiasis/epidemiología , Giardiasis/veterinaria , Giardiasis/parasitología , Filogenia , Diarrea/veterinaria , Heces/parasitología , República de Corea/epidemiología , Prevalencia , GenotipoRESUMEN
For rapid and reliable detection of porcine epidemic diarrhea virus (PEDV) from pig clinical samples, a multiplex, real-time, reverse transcription loop-mediated isothermal amplification (mqRT-LAMP) was developed using two sets of primers and assimilating probes specific to the PEDV N gene and the Sus scrofa ß-actin gene, which was used as an endogenous internal positive control (EIPC) to avoid false-negative results. The assay specifically amplified both target genes of PEDV and EIPC in a single reaction without any interference but did not amplify other porcine viral nucleic acids. The limit of detection was 10 copies/µL, 100-fold lower than that of a reverse transcription-polymerase chain reaction (RT-PCR) and equivalent to that of quantitative/real-time RT-PCR (qRT-PCR). This assay has high repeatability and reproducibility with coefficients of variation < 4.0%. The positive signal of the mqRT-LAMP assay was generated within 25 min, demonstrating advantages in rapid detection of PEDV over RT-PCR or qRT-PCR assay, which require at least 2 h turnaround times. In clinical evaluation, the detection rate of PEDV by mqRT-LAMP assay (77.3%) was higher than that of RT-PCR assay (69.7%), and comparable to qRT-PCR (76.8%) with almost 100% concordance (kappa value 0.98). The developed mqRT-LAMP assay can serve as an advanced alternative method for PEDV diagnosis because it has high sensitivity and specificity, rapidity, and reliability even in resource-limited laboratories.
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Infecciones por Coronavirus , Virus de la Diarrea Epidémica Porcina , Enfermedades de los Porcinos , Animales , Porcinos , Virus de la Diarrea Epidémica Porcina/genética , Transcripción Reversa , Reproducibilidad de los Resultados , Infecciones por Coronavirus/diagnóstico , Infecciones por Coronavirus/veterinaria , Sensibilidad y Especificidad , Enfermedades de los Porcinos/diagnóstico , Técnicas de Amplificación de Ácido Nucleico/métodosRESUMEN
Novel swine orthopneumovirus (SOV) infections have been identified in pigs in the USA and some European countries but not in Asian countries, including South Korea, to date. The current study reports the first SOV infections in four domestic pig farms located in four provinces across South Korea. The detection rate of SOV in oral fluid samples using qRT-PCR was 4.4% (14/389), indicating the presence of the virus in pigs at commercial farms in Korea. Two complete genome sequences and one glycoprotein (G) gene sequence were obtained from SOV-positive samples. The complete genome analysis of KSOV-2201 and KSOV-2202 strains showed 98.2 and 95.4% homologies with a previously reported SOV, and the phylogenetic tree exhibited a high correlation with a previously reported SOV strain from the US and a canine pneumovirus (CPnV) strain from China. Based on the genetic analysis of the viral G gene, the murine pneumonia virus (MPV)-like orthopneumoviruses (MLOVs) were divided into two genogroups (G1 and G2). Seventeen CPnVs and two feline pneumoviruses were grouped into G1, while the Korean SOV strains identified in this study were grouped into G2 along with one SOV and two CPnVs. These results will contribute to expanding our understanding of the geographical distribution and genetic characteristics of the novel SOV in the global pig population.
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Pneumovirus , Enfermedades de los Porcinos , Ratones , Porcinos , Animales , Gatos , Perros , Sus scrofa , Virus Sincitiales Respiratorios , Granjas , Filogenia , Enfermedades de los Porcinos/epidemiología , República de Corea/epidemiologíaRESUMEN
Feline panleukopenia virus (FPV), a member of the species Protoparvovirus carnivoran1, is one of the most fatal pathogens of domestic and wild carnivores. The virus endemically infects domestic carnivores worldwide and its cross-species transmission threatens endangered wild carnivores, including Siberian tigers. In this study, a fatal FPV infection in endangered Siberian tigers was investigated to trace the origin of the virus and elucidate the reason behind FPV's infection of the vaccinated tigers. Our genetic characterization and phylogenetic analysis revealed that the virus detected in the infected tigers, designated as the KTPV-2305 strain, was closely related to FPV strains circulating in Korean cats, suggesting that it might have been transmitted from stray cats wandering around the zoo. Compared with the prototype FPV reference strains, the KTPV-2305 strain carried three distinct amino acid (aa) mutations in the VP2 protein sequence (I101T, I232V, and L562V) in this study. These three mutations are commonly found in most global FPV strains, including Korean strains, indicating that these mutations are common evolutionary characteristics of currently circulating global FPVs. The reason why the vaccinated tigers were infected with FPV was most likely the insufficient protective immunity of the affected tigress or vaccine failure triggered by the interference of maternal-derived antibodies in the affected tiger cubs. These findings suggest that improved vaccination guidelines are urgently needed to save the lives of wild carnivores from this fatal virus.
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Porcine reproductive and respiratory syndrome virus (PRRSV) is one of the most important pathogens in the swine industry worldwide. In Korea, Fostera PRRS commercial modified live virus (MLV) vaccines have been used since 2014 to control the PRRSV infection. In this study, two PRRSV-2 strains (20D160-1 and 21R2-63-1) were successfully isolated, and their complete genomic sequences were determined. Genetic analysis showed that the two isolates have recombination events between the P129-like strain derived from the Fostera PRRS MLV vaccine and the strain of lineage 1. The 20D160-1 indicated that partial ORF2 to partial ORF4 of the minor parental KNU-1902-like strain, which belongs to Korean lineage C (Kor C) of lineage 1, was inserted into the major parental P129-like strain. The 21R2-63-1 revealed that partial ORF1b of the P129-like strain was inserted into the backbone of the NADC30-like strain. This study is the first to report natural recombinant strains between Fostera PRRS MLV-like strain and the field strain in Korea. These results may have significant implications for MLV evolution and the understanding of PRRSV genetic diversity, while highlighting the need for continuous surveillance of PRRSV.
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Síndrome Respiratorio y de la Reproducción Porcina , Virus del Síndrome Respiratorio y Reproductivo Porcino , Vacunas Virales , Virus no Clasificados , Animales , Virus ADN , Filogenia , Virus del Síndrome Respiratorio y Reproductivo Porcino/genética , Recombinación Genética , Porcinos , Vacunas Atenuadas , Vacunas Virales/genéticaRESUMEN
This study was conducted to examine the in vitro activity of antimicrobials against Campylobacter spp. isolates from chicken and human sources and the genetic interrelation among them. During 2004-2008, a total of 173 Campylobacter spp. isolated from chicken meats (60 domestic and 62 imported chicken meats) and humans (n = 51) were tested for susceptibility to nine antimicrobials. Of 173 isolates, 140 (80.9%) showed multidrug resistance (MDR) against three to eight antimicrobials. The most frequent pattern type was MDR to four antimicrobials: ciprofloxacin, nalidixic acid, ampicillin, and tetracycline. Over 52.6% (91/173) of the isolates tested were resistant to these four antibiotics simultaneously. Especially, two and five isolates originated from Korea and Brazil showed resistance against all antibiotics tested, except for florfenicol. Further, 95% (57/60) of the isolates originated from domestic chicken showed resistance to ciprofloxacin, the antimicrobial agent of choice for treatment of human campylobacteriosis. Genotypic characterization of all Campylobacter isolates performed by pulsed-field gel electrophoresis yielded 74 types among the 173 isolates. Isolates sharing the same or similar genetic clusters were detected in different countries at different times. The pulsed-field gel electrophoresis patterns of chicken-related isolates were closely related to those of isolates from humans with gastroenteritidis. The results of this study suggest that MDR Campylobacter spp. are widespread and that Campylobacter with similar genotypes are circulating both in humans and in chicken meat in Korea.
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Antibacterianos/farmacología , Infecciones por Campylobacter/microbiología , Campylobacter/efectos de los fármacos , Campylobacter/genética , Carne/microbiología , Animales , Brasil , Campylobacter/clasificación , Campylobacter/aislamiento & purificación , Pollos , ADN Bacteriano/química , Farmacorresistencia Bacteriana Múltiple , Electroforesis en Gel de Campo Pulsado , Europa (Continente) , Contaminación de Alimentos/análisis , Genotipo , Humanos , Pruebas de Sensibilidad Microbiana , República de Corea , Tailandia , Estados UnidosRESUMEN
Foot-and-mouth (FMD) is endemic in Cambodia with numerous outbreaks in cattle, pigs and other susceptible animal species reported every year. Historically, these outbreaks were caused by the FMD virus (FMDV) of serotype O PanAsia and Mya-98 lineages and serotype A Sea-97 lineage. However, the trans-pool movement of FMDV between inter-pool regions or countries throughout FMD endemic regions has raised concerns regarding infection with the new genotype or serotype of FMDV in Cambodia. In this study, 19 sequences of VP1 coding region obtained from 33 clinical samples collected from FMDV-affected cattle farms in Cambodia during January to March 2019 were genetically characterized to identify the genotypes/lineages of FMDV. Phylogenetic analysis of VP1 coding sequences revealed that recent field viruses belonged to O/ME-SA/Ind-2001e (15.8%), O/ME-SA/PanAsia (52.7%), and A/ASIA/Sea-97 (31.5%). Besides, the field viruses of O/ME-SA/Ind-2001e in Cambodia showed 93.5-96.8% identity with the VP1 coding sequences of the same sublineage viruses from pool 1 and 2 surrounding Cambodia. This is the first report of O/ME-SA/Ind-2001e infection in Cambodia, suggesting that the trans-pool movement of the new genotype should be closely monitored for efficient control of FMD.
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Campylobacteriosis in humans is primarily caused by handling or consuming contaminated poultry or their products. The aims of this study were to estimate the prevalence of Campylobacter spp. in domestic and imported poultry meat in Korea and to further characterize the obtained isolates. From 2004 to 2008, a total of 475 domestic and 867 imported raw poultry meat samples were examined for the presence of Campylobacter spp. Among 475 domestic poultry meat samples, Campylobacter jejuni and Campylobacter coli were isolated from 219 (46.1%) and 156 (32.8%), respectively. Relative prevalence of C. jejuni and C. coli was higher in meat from Brazil (39/78, 50.0% and 7/78, 8.9%) and France (32/96, 33.3% and 8/96, 8.3%), whereas lower in meat from Denmark (72/516, 14.0% and 12/516, 2.3%) and Thailand (5/39, 12.8% and 3/39, 7.6%). The resistance to ampicillin and tetracycline was highly prevalent in Campylobacter spp. from most countries investigated, whereas lower in meat from Denmark. On the other hand, the prevalence of erythromycin and gentamicin resistance was less than 10% in most countries. The resistance rate to nalidixic acid, ciprofloxacin, and enrofloxacin ranged from 11.9% to 87.5%. The use of fla-polymerase chain reactionrestriction fragment length polymorphism for epidemiological analysis found that some pattern types were considerably more frequent and distinct in meat from each country. In conclusion, we report the presence of high contamination in domestic and imported poultry meat in Korea and the antimicrobial and genetic diversity of Campylobacter spp. between each country.
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Campylobacter/aislamiento & purificación , Microbiología de Alimentos , Carne/microbiología , Aves de Corral/microbiología , Animales , Brasil , Campylobacter/efectos de los fármacos , Campylobacter/genética , Campylobacter coli/genética , Campylobacter coli/aislamiento & purificación , Campylobacter jejuni/genética , Campylobacter jejuni/aislamiento & purificación , Dinamarca , Farmacorresistencia Bacteriana/genética , Francia , Corea (Geográfico) , Reacción en Cadena de la Polimerasa , Polimorfismo de Longitud del Fragmento de Restricción , TailandiaRESUMEN
Rapid and specific detection of foot-and-mouth disease virus (FMDV) is a key factor for promoting prompt control of FMD outbreaks. In this study, a real-time reverse transcription loop-mediated isothermal amplification (RRT-LAMP) assay with high sensitivity, rapidity and reliability was developed using a targeted gene-specific assimilating probe for real-time detection of seven FMDV serotypes. Positive assay signals were generated within 15 min for the lowest concentration of a standard RNA sample at 62°C; this was substantially faster than that achieved by the OIE (World Organisation for Animal Health)-recommended real-time quantitative reverse transcription polymerase chain reaction (qRT-PCR) assay. The new assay specifically amplified the 3D gene of all seven FMDV serotypes and did not amplify other viral nucleic acids. The detection limit of the assay was 102 copies/µl which is comparable to that achieved by qRT-PCR. Furthermore, using clinical samples, the results of the RRT-LAMP assay were largely in agreement with those from the qRT-PCR assay with a kappa value (95% confidence interval [CI]) of 0.94 (0.86-1.02). The established RRT-LAMP assay that features assimilating probes is an advanced molecular diagnostic tool that is easily applicable to a wide range of circumstances and has high potential for use as an on-site diagnostic assay for rapid, specific, and reliable detection of FMDVs in clinical samples.
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Virus de la Fiebre Aftosa/aislamiento & purificación , Fiebre Aftosa/diagnóstico , Técnicas de Diagnóstico Molecular/veterinaria , Técnicas de Amplificación de Ácido Nucleico/veterinaria , Reacción en Cadena en Tiempo Real de la Polimerasa/veterinaria , Reacción en Cadena de la Polimerasa de Transcriptasa Inversa/veterinaria , Animales , Reproducibilidad de los Resultados , Sensibilidad y EspecificidadRESUMEN
Foot-and-mouth disease (FMD) is a highly contagious and economically devastating disease affecting cloven-hoofed livestock worldwide. FMD virus (FMDV) type A is one of the most common causes of FMD outbreaks among the seven FMDV serotypes, and its serological diagnosis is therefore important to confirm FMDV type A infection and to determine FMD vaccine efficacy. Here, we generated monoclonal antibodies (mAbs) specific to FMDV type A via hybridoma systems using an inactivated FMDV type A (A22/Iraq/1964) and found 4 monoclones (#29, #106, #108, and #109) with high binding reactivity to FMDV type A among 594 primary clones. In particular, the #106 mAb had a higher binding reactivity to the inactivated FMDV type A than the other mAbs and a commercial mAb. Moreover, the #106 mAb showed no cross-reactivity to inactivated FMDV type South African territories 1, 2, and 3, and low reactivity to inactivated FMDV type O (O1 Manisa). Importantly, the solid-phase competitive ELISA (SPCE) using horseradish peroxidase (HRP)-conjugated #106 mAb detected FMDV type A-specific Abs in sera from FMD type A-vaccinated cattle more effectively than a commercial SPCE. These results suggest that the newly developed FMDV type A-specific mAb might be useful for diagnostic approaches for detecting Abs against FMDV type A.
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In this article, we report the complete genome sequence of foot-and-mouth disease virus (FMDV) strain O/VN1/2014 isolated in Vietnam (Lao Cai) in 2014. The virus belongs to serotype O, topotype South East Asia (SEA), and genotype Mya-98 (O/SEA/Mya-98). It is the latest complete genome information for the genotype O/SEA/Mya-98 in Vietnam since 2009.
RESUMEN
Bovine tuberculosis is a chronic contagious disease responsible for major agricultural economic losses. Abattoir monitoring and trace-back systems are an appropriate method to control bovine tuberculosis, particularly in beef cattle. In the present study, a trace-back system was applied to bovine tuberculosis cases in Korean native Hanwoo beef cattle. Bovine tuberculosis was detected in three index beef cattle during abattoir monitoring in Jeonbuk Province, Korea, and the original herds were traced back from each index cow. All cattle in each original herd were subjected to tuberculin skin test. The positive rates in the tuberculin skin test were 64.6% (62 of 96), 4.8% (2 of 42), and 8.1% (3 of 37) at farms A, B, and C, respectively. On post-mortem examination of 56 tuberculin-positive cattle, 62% had granulomatous lesions, and Mycobacterium bovis was cultured from 40 (71.4%) of the cattle. Molecular typing by spoligotyping and the mycobacterial interspersed repetitive unit-variable-number tandem repeat assay revealed the genotype of the M. bovis strains from the index cattle were same as the M. bovis genotype in each original herd. The results suggest that tracing back from index cattle to the original herd is an effective method to control bovine tuberculosis in beef cattle.
Asunto(s)
Crianza de Animales Domésticos/métodos , Brotes de Enfermedades/veterinaria , Tipificación Molecular/veterinaria , Mycobacterium bovis/aislamiento & purificación , Tuberculosis Bovina/epidemiología , Animales , Bovinos , Femenino , Secuencias Repetitivas Esparcidas/genética , Repeticiones de Minisatélite/genética , Tipificación Molecular/métodos , República de Corea/epidemiología , Prueba de Tuberculina/veterinaria , Tuberculosis Bovina/microbiologíaRESUMEN
Rapid and accurate diagnosis of foot-and-mouth disease viruses (FMDV) is essential for the prompt control of FMD outbreaks. Reverse transcription polymerase chain reaction (RT-PCR) and real-time quantitative RT-PCR (qRT-PCR) are used for routine FMDV diagnosis as World Organisation for Animal Health-recommended diagnostic assays. However, these PCR-based assays require sophisticated equipment, specialized labour, and complicated procedures for the detection of amplified products, making them unsuitable for under-equipped laboratories in developing countries. In this study, to overcome these shortcomings, a simple, rapid, and cost-effective reverse transcription loop-mediated isothermal amplification (RT-LAMP) assay was developed for the sensitive and specific detection of serotype A FMDV circulating in the pool 1 region. The amplification could be completed in 40 min at 62°C, and the results could be visually detected by the naked eye without any additional detection systems. The assay specifically amplified the VP1 gene of the Sea-97 genotype of serotype A FMDV, but it did not amplify other viral nucleic acids. The limit of detection of the assay was 102 TCID50 /ml, which is 10 times more sensitive than RT-PCR and is comparable to the sensitivity of qRT-PCR. Evaluation of the assay using different FMDV strain serotypes showed 100% agreement with the results of RT-PCR. Surprisingly, the previously reported RT-LAMP assay did not detect all eight tested strains of serotype A FMDVs, due to multiple mismatches between primer and template sequences, demonstrating that it is not suitable for detecting serotype A FMDVs circulating in pool 1-region countries. Conversely, the newly developed RT-LAMP assay using improved primers can rapidly and accurately diagnose the genotype of Sea-97 strains of serotype A FMDVs from the pool 1 region. The established RT-LAMP assay in this study is a simple, rapid, specific, sensitive, and cost-effective tool for the detection of serotype A FMDV in the resource-limited pool 1-region countries.