Publications by authors named "Satoshi Sekiguchi"

103 Publications

Relationship between Allelic Heterozygosity in and Proviral Loads in Bovine Leukemia Virus-Infected Cattle.

Animals (Basel) 2021 Mar 1;11(3). Epub 2021 Mar 1.

Center for Animal Disease Control, University of Miyazaki, 1-1 Gakuen-Kibanadai-Nishi, Miyazaki 889-2192, Japan.

Enzootic bovine leukosis is a lethal neoplastic disease caused by bovine leukemia virus (BLV), belongs to family Retroviridae. The BLV proviral load (PVL) represents the quantity of BLV genome that has integrated into the host's genome in BLV-infected cells. Bovine leukocyte antigen () class II allelic polymorphisms are associated with PVLs in BLV-infected cattle. We sought to identify relationships between allelic heterozygosity and BLV PVLs among different cattle breeds. Blood samples from 598 BLV-infected cattle were quantified to determine their PVLs by real-time polymerase chain reaction. The results were confirmed by a BLV-enzyme-linked immunosorbent assay. Restriction fragment length polymorphism-polymerase chain reaction identified 22 alleles. Multivariate negative binomial regression modeling was used to test for associations between BLV PVLs and alleles. , , , , , , and alleles were significantly associated with low PVLs. was significantly associated with high PVLs. Some heterozygous allele combinations were associated with low PVLs , , , , and ; others were associated with high PVLs , , , , and . Interestingly, the heterozygous allele was always strongly and independently associated with low PVLs. This is the first reported evidence of an association between heterozygous allelic combinations and BLV PVLs.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.3390/ani11030647DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC7999362PMC
March 2021

Identification of and Related Enterobacteriaceae and Examination of Their Phenotypic Antimicrobial Resistance Patterns: A Pilot Study at A Wildlife-Livestock Interface in Lusaka, Zambia.

Antibiotics (Basel) 2021 Feb 26;10(3). Epub 2021 Feb 26.

Department of Veterinary Science, Faculty of Agriculture, University of Miyazaki, Miyazaki 889-2192, Japan.

A cross-sectional study was used to identify and assess prevalence and phenotypic antimicrobial resistance (AMR) profiles of and other enterobacteria isolated from healthy wildlife and livestock cohabiting at a 10,000 acres game ranch near Lusaka, Zambia. Purposive sampling was used to select wildlife and livestock based on similarities in behavior, grazing habits and close interactions with humans. Isolates ( = 66) from fecal samples collected between April and August 2018 ( = 84) were examined following modified protocols for bacteria isolation, biochemical identification, molecular detection, phylogenetic analysis, and antimicrobial susceptibility testing by disc diffusion method. Data were analyzed using R software, Genetyx ver.12 and Mega 6. Using Applied Profile Index 20E kit for biochemical identification, polymerase chain reaction assay and sequencing, sixty-six isolates were identified to species level, of which (72.7%, 48/66), (1.5%, 1/66), (22.7%, 14/66), (1.5%, 1/66) and (1.5%, 1/66), and their relationships were illustrated in a phylogenetic tree. Phenotypic antimicrobial resistance or intermediate sensitivity expression to at least one antimicrobial agent was detected in 89.6% of the , and 73.3% of the isolates. The isolates exhibited the highest resistance rates to ampicillin (27%), ceftazidime (14.3%), cefotaxime (9.5%), and kanamycin (9.5%). Multidrug resistance (MDR) was detected in 18.8% of isolates while only 13.3% isolates showed MDR. The MDR was detected among isolates from impala and ostrich (wild animals in which no antimicrobial treatment was used), and in isolates from cattle, pigs, and goats (domesticated animals). This study indicates the possible transmission of drug-resistant microorganisms between animals cohabiting at the wildlife-livestock interface. It emphasizes the need for further investigation of the role of wildlife in the development and transmission of AMR, which is an issue of global concern.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.3390/antibiotics10030238DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC7996741PMC
February 2021

Characterization of bovine interleukin-2 stably expressed in HEK-293 cells.

J Vet Med Sci 2021 Jan 11;83(1):134-141. Epub 2020 Nov 11.

Department of Veterinary Sciences, Faculty of Agriculture, University of Miyazaki, 1-1 Gakuen-Kibanadai-Nishi, Miyazaki 889-2192, Japan.

Interleukin 2 (IL-2) is a pleotropic cytokine and well-known as a T cell growth factor in immunology. It is now known to exert both immunostimulatory and immunosuppressive effects, optimizing immunological microenvironments for effector and regulatory T cell responses. The immunomodulatory role of IL-2 is critical for deciding whether or not T cell responses against specific antigens result in protection. We have established a mammalian cell line (HEK-293) stably expressing bovine IL-2 (boIL-2) (designated as HEK-293/boIL-2), using the piggyBac transposon system. The concentration of recombinant bovine IL-2 (rboIL-2) in the culture supernatant of HEK-293/boIL-2 reached 100 ng/ml on day 7 and showed similar proliferative activity to recombinant human IL-2 (rhuIL-2) for bovine peripheral mononuclear blood cells. Although rhuIL-2 has been often used to activate bovine T cells, our results indicate that characteristics of the T cell activation through rboIL-2 and huIL-2 appear slightly but significantly different. Interestingly, the rboIL-2/anti-boIL-2 monoclonal antibody (C5) (rboIL-2/C5) complex strongly induced proliferation of bovine NKp46cells, natural killer (NK) cells, in vitro. This indicates that the rboIL-2/C5 complex could function as an IL-2 agonist specifically to increase the NK cell population, which in turn could enhance the activity of NK cells leading to protective immunity.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.1292/jvms.20-0423DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC7870392PMC
January 2021

Quantitative Risk Assessment for the Introduction of Bovine Leukemia Virus-Infected Cattle Using a Cattle Movement Network Analysis.

Pathogens 2020 Oct 28;9(11). Epub 2020 Oct 28.

Center for Animal Disease Control, University of Miyazaki, Miyazaki 889-2192, Japan.

The cattle industry is suffering economic losses caused by bovine leukemia virus (BLV) and enzootic bovine leukosis (EBL), the clinical condition associated with BLV infection. This pathogen spreads easily without detection by farmers and veterinarians due to the lack of obvious clinical signs. Cattle movement strongly contributes to the inter-farm transmission of BLV. This study quantified the farm-level risk of BLV introduction using a cattle movement analysis. A generalized linear mixed model predicting the proportion of BLV-infected cattle was constructed based on weighted in-degree centrality. Our results suggest a positive association between weighted in-degree centrality and the estimated number of introduced BLV-infected cattle. Remarkably, the introduction of approximately six cattle allowed at least one BLV-infected animal to be added to the farm in the worst-case scenario. These data suggest a high risk of BLV infection on farms with a high number of cattle being introduced. Our findings indicate the need to strengthen BLV control strategies, especially along the chain of cattle movement.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.3390/pathogens9110903DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC7693104PMC
October 2020

A descriptive survey of porcine epidemic diarrhea in pig populations in northern Vietnam.

Trop Anim Health Prod 2020 Nov 4;52(6):3781-3788. Epub 2020 Oct 4.

Department of Veterinary Science, Faculty of Agriculture, University of Miyazaki, Miyazaki, Japan.

Porcine epidemic diarrhea (PED) virus (PEDV) is a globally emerging and re-emerging epizootic swine virus that causes massive economic losses in the swine industry, with high mortality in piglets. In Vietnam, PED first emerged in 2009 and has now developed to an endemic stage. This is the first cross-sectional survey performed to evaluate the proportion of PEDV-positive swine farms in Vietnam from January 2018 to February 2019. Fecal samples from 327 pig farms in northern Vietnam were collected and tested for PEDV infection by reverse transcription-loop-mediated isothermal amplification (RT-LAMP) method. The proportion of PEDV-positive farms was 30.9% and PEDV-positive farms were distributed throughout the study area. The highest proportion of PEDV-positive farms was 70% (7/10) among nucleus production type farms (P < 0.05). Higher proportions of PEDV-positive farms were found in the Northeast and Red River Delta areas, which are the major areas of pig production (P < 0.05). The proportion of PEDV-positive farms was higher among larger farms (P < 0.05). Our findings illustrate the high proportion of PEDV-positive farms in the Vietnamese pig population and will help to better understand the epidemiological dynamics of PED infection, to estimate impact, and establish and improve prevention and control measures.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.1007/s11250-020-02416-1DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC7532947PMC
November 2020

FMD-VS: A virtual sensor to index FMD virus scattering.

PLoS One 2020 11;15(9):e0237961. Epub 2020 Sep 11.

Faculty of Engineering, University of Miyazaki, Miyazaki, Japan.

Foot-and-mouth disease (FMD) models-analytical models for tracking and analyzing FMD outbreaks-are known as dominant tools for examining the spread of the disease under various conditions and assessing the effectiveness of countermeasures. There has been some remarkable progress in modeling research since the UK epidemic in 2001. Several modeling methods have been introduced, developed, and are still growing. However, in 2010 when a FMD outbreak occurred in the Miyazaki prefecture, a crucial problem reported: Once a regional FMD outbreak occurs, municipal officials in the region must make various day-to-day decisions throughout this period of vulnerability. The deliverables of FMD modeling research in its current state appear insufficient to support the daily judgments required in such cases. FMD model can be an efficient support tool for prevention decisions. It requires being conversant with modeling and its preconditions. Therefore, most municipal officials with no knowledge or experience found full use of the model difficult. Given this limitation, the authors consider methods and systems to support users of FMD models who must make real-time epidemic-related judgments in the infected areas. We propose a virtual sensor, designated "FMD-VS," to index FMD virus scattering in conditions where there is once a notion of FMD; and (2) shows how we apply the developed FMD-VS technique during an outbreak. In (1), we show our approach to constructing FMD-VS based on the existing FMD model and offer an analysis and evaluation method to assess its performance. We again present the results produced when the technique applied to 2010 infection data from the Miyazaki Prefecture. For (2), we outline the concept of a method that supports the prevention judgment of municipal officials and show how to use FMD-VS.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://journals.plos.org/plosone/article?id=10.1371/journal.pone.0237961PLOS
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC7485836PMC
October 2020

Evaluating the Risk Factors for Infection in an Endemic Area of Vietnam.

Front Vet Sci 2020 29;7:433. Epub 2020 Jul 29.

Center for Animal Disease Control, University of Miyazaki, Miyazaki, Japan.

(PEDV) causes enteritis, vomiting, watery diarrhea, and high mortality in suckling pigs, threatening the swine industry. Porcine epidemic diarrhea (PED) re-emerged globally in 2013 in many important swine-producing countries in Asia and the Americas. Several studies have identified the risk factors for the spread of PEDV in acute outbreaks. However, limited information is available on the risk factors for the transmission of PEDV in endemic regions. We hypothesized that poor biosecurity, location, and some social or cultural practices are the main risk factors for PEDV transmission in the Vietnamese pig population. The aim of this study was to evaluate the potential risk factors for the transmission of PEDV in an endemic area in Vietnam. In this case-control study, questionnaires containing 51 questions were completed for 92 PEDV-positive and 95 PEDV-negative farms. A logistic regression analysis was performed to assess the risk factors associated with PEDV infection. Province and the total number of pigs were included as random effects to determine their influence on the risk of PEDV infection. Twenty-nine variables of interest that have been associated with PEDV status were analyzed in a univariate analysis ( <0.20), with backward stepwise selection. Only three of these 29 variables in four models remained significant PEDV risk factors in the final model: farrow-to-wean production type, distance from the farm to the slaughterhouse (<1,000 m), and the presence of chickens on site ( <0.05). This is the first study to identify the main risk factors for PEDV infection in an endemic area. Our findings suggest that hygiene measures should be strictly implemented on farms for the effective control and prevention of PEDV infection.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.3389/fvets.2020.00433DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC7403480PMC
July 2020

Production of a correctly assembled fibrinogen using transgenic silkworms.

Transgenic Res 2020 06 4;29(3):339-353. Epub 2020 May 4.

Transgenic Silkworm Department, Immuno-Biological Laboratories Co., Ltd., 1-26-2 Asahi-cho, Maebashi, Gunma, 371-0014, Japan.

Fibrinogen from human blood is used as a main component of coagulants, including surgical tissue sealants. The development of a recombinant human fibrinogen (rFib) is anticipated to eliminate the risks of blood-borne infections. Here, we report the efficient production of rFib in a transgenic silkworm system. A silkworm line carrying cDNAs of the fibrinogen Aα and γ chains (Aα/γ-silkworm) produced Aα and γ chains in its cocoons, however, the Bβ chains were not detected from cocoons of another silkworm line carrying the cDNA of fibrinogen Bβ chains (Bβ-silkworm). A silkworm line for all three fibrinogen chains was generated by crossing Aα/γ-silkworms with Bβ-silkworms, which secreted AαBβγ fibrinogen (rFib) into cocoons at high contents. The N-terminal amino acid sequences of the three rFib chains were identical to those of the corresponding chains of native fibrinogen (nFib). The N-glycan profile of the rFib comprised oligomannose-type (53%), complex-type (34%), and paucimannose-type (13%); neither high-mannose-type (six or more mannose residues) nor core-fucosylated glycans were observed. The coagulation activity of the rFib was evaluated for the amount of thrombin-released fibrinopeptide A (FpA) and the kinetics for turbidity increase (non-covalent network formation) in the solution. FpA release rates were equivalent between rFib and nFib; by contrast, the kinetics of the turbidity increase for rFib were accelerated nearly two-fold, for both the rate and maximum value, compared to those of nFib. These results demonstrate that the rFib produced in the transgenic silkworm system is comparable to nFib in both physical and coagulative properties. This rFib is a promising candidate component for safe hemostatic pharmaceuticals.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.1007/s11248-020-00202-1DOI Listing
June 2020

Assessment of abortion risk of sows on Japanese commercial farms infected with porcine epidemic diarrhea virus.

Anim Sci J 2020 Jan-Dec;91(1):e13377

Center for Animal Disease Control, University of Miyazaki, Miyazaki, Japan.

The objectives of this study were to assess abortion risk (AR) and the number of piglets that died during suckling periods per litter (DP) in farms infected with porcine epidemic diarrhea (PED) in relation to herd immunization procedures. Data were obtained from 91 farms in Japan that had PED infection during 2013 to 2014. The 91 PED-positive farms were asked the number of abortions that occurred and DP for 3 months (1 month before PED outbreak (previous month), 1 month after PED outbreak (the month of PED), and from 1 month after PED outbreak to 2 months after PED outbreak (following month)). AR in each month was calculated as the number of abortions divided by sow inventory. Both AR and DP in the month of PED were higher than those in the previous and following months (p < .05). Farms that performed a herd immunization procedure had higher AR and DP in the month of PED than those that did not perform the procedure (p < .05). In summary, PED occurrence increased AR and DP.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.1111/asj.13377DOI Listing
September 2020

A questionnaire survey of the illegal importation of pork products by air travelers into Japan from China and exploration of causal factors.

Prev Vet Med 2020 Apr 4;177:104947. Epub 2020 Mar 4.

Department of Global Agricultural Sciences, Graduate School of Agricultural and Life Sciences, the University of Tokyo, Tokyo, Japan. Electronic address:

With the aim of obtaining information to establish an import risk assessment on African swine fever (ASF) and other transboundary animal diseases (TADs) into Japan, a questionnaire survey was conducted between 1 August and 20 September 2019 on air travellers arriving into Japan from China. There were 248 responses with 2.8 % of respondents illegally importing pork products. The quantity imported per traveller varied between 250 g and 2 kg. Concerning the travellers' perception in regard to the difficulty of importing a pork product in their luggage, 32 respondents (12.9 %) considered it very easy or rather easy and 216 (87.1 %) very difficult or rather difficult. In regard to the recognition of respondents of the illegality of importing pork products into Japan, seven respondents (2.8 %) did not consider this practice to be illegal whilst 241 (97.2 %) had some idea of the illegal nature of this behaviour. The regression analysis revealed that the practice of illegal importation of pork products was significantly affected by the level of difficulty perception held by the traveller (P < 0.001) and that the difficulty perception is significantly affected by the level of recognition of illegality by the traveller (P < 0.001). The result of this study will not only provide useful data in developing a model to assess the probability of introduction of ASF and other TADs into Japan and other countries, but also in monitoring the effect of measures taken by the government to reduce the illegal importation of meat and meat products.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.1016/j.prevetmed.2020.104947DOI Listing
April 2020

Establishment of a novel diagnostic test for Bovine leukaemia virus infection using direct filter PCR.

Transbound Emerg Dis 2020 Jul 17;67(4):1671-1676. Epub 2020 Feb 17.

Department of Veterinary Science, Faculty of Agriculture, University of Miyazaki, Miyazaki, Japan.

Enzootic bovine leucosis (EBL) is a neoplastic disease of cattle caused by Bovine leukaemia virus (BLV). EBL causes great economic losses, so a fast and reliable diagnostic method is critical for understanding the status of BLV. This will allow us to control BLV infections efficiently and mitigate economic losses. In this study, we established a direct diagnostic test for BLV using dried blood-spotted filter papers without sample pre-treatment. The study was based on 159 clinical blood specimens collected in EDTA from one farm in Kyushu, Japan. The blood-spotted filter papers were used as the template for direct filter PCR. When an ELISA was used as the diagnostic gold standard, the sensitivity and specificity of the direct filter PCR were 90.1% and 97.5%, respectively. The kappa value for the direct filter PCR and real-time PCR methods was 0.97. The dried blood samples spotted onto filter papers were stable for at least 10 days at room temperature, even when the samples were from cattle with a low BLV proviral load. Direct filter PCR is a rapid, easy, reliable and cost-effective diagnostic test that directly detects the BLV proviral genome in clinical blood specimens without DNA extraction. Moreover, it simplifies the collection, transportation and storage procedures for clinical blood specimens.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.1111/tbed.13506DOI Listing
July 2020

Effects of a single-bolus bupivacaine injection into the coccygeal spinal canal of rabbits.

J Vet Med Sci 2020 Feb 22;82(2):197-203. Epub 2020 Jan 22.

Veterinary Teaching Hospital, Faculty of Agriculture, University of Miyazaki, 1-1 Gakuenkibanadai-Nishi, Miyazaki 889-2192, Japan.

It has been reported that drugs intended for epidural administration through the lumbosacral junction are accidentally administered into the subarachnoid space frequently in rabbits. Therefore, we evaluated the epidural single-bolus injection technique for the administration of bupivacaine into the coccygeal spinal canal of rabbits. After epidural distribution was confirmed by the injection of iohexol into the coccygeal spinal canal, 0.3 ml/kg 0.5% bupivacaine or 0.3 ml/kg normal saline was injected via the same needle. After the first attempt of iohexol injection, although the contrast was found in the epidural space in all rabbits, the additional contrast was also found in blood vessel in 3 rabbits and in muscular layer in 1 rabbit. Subarachnoid distribution was not observed in any of the rabbits. The time taken to regain normal anal reflex, movement of the hind limbs during walking, conscious proprioception of the hind limbs, and pain sensation of the tail and left hind limb, following coccygeal spinal canal injection, were significantly longer in the bupivacaine group than in the normal saline group. These findings indicated that coccygeal epidural injection of bupivacaine in rabbits may provide anesthesia for the hind limbs, perineum, and tail, but inadvertent vascular entry of the epidural drug may occur.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.1292/jvms.19-0555DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC7041980PMC
February 2020

Development of indirect enzyme-linked immunosorbent assay for detection of porcine epidemic diarrhea virus specific antibodies (IgG) in serum of naturally infected pigs.

BMC Vet Res 2019 Nov 12;15(1):409. Epub 2019 Nov 12.

Department of Veterinary Pathology, Faculty of Agriculture, University of Miyazaki, 1-1 Gakuenkibanadai-Nishi, Miyazaki, 889-2192, Japan.

Background: Porcine epidemic diarrhea virus (PEDV) infection is a highly contagious infectious disease causing watery diarrhea, vomiting, dehydration and high mortality rate in newborn piglets. PEDV infection can cause high economic losses in pig industry. In Japan, a PEDV outbreak occurred with high mortality from 2013 to 2015. Even though until now, PEDV infection occurs sporadically. For the control and monitoring of PEDV infection, not only symptomatic pigs, but also asymptomatic pigs should be identified. The objective of this study is to develop and optimize novel indirect ELISA as a simple, rapid, sensitive and specific method for the detection of anti-PEDV antibodies and evaluate the efficacy of the assay as a diagnostic method for PED.

Results: One hundred sixty-two serum samples, consisting of 81 neutralization test (NT) positive and 81 NT negative sera, were applied to the assay. Indirect ELISA test based on whole virus antigen (NK94P6 strain) derived from Vero cell culture was evaluated by receiver operating characteristic (ROC) analysis with neutralization test (NT) as a reference method, and cut-off value was determined as 0.320 with sensitivity and specificity of 92.6 and 90.1%, respectively. The area under curve (AUC) was 0.949, indicating excellent accuracy of indirect ELISA test. There was significant positive correlation between indirect ELISA and neutralization test (R = 0.815, P < 0.05). Furthermore, the kappa statics showed the excellent agreement between these two tests (kappa value = 0.815). In addition, the sensitivity and specificity of preserved plates with different periods (1 day, 2 weeks, 1, 2, 3, 4, 5 and 6 months) after drying antigen coated plates were 100% and 80-100%, respectively.

Conclusions: The developed indirect ELISA test in our study would be useful as a reliable test for serological survey and disease control of PEDV infection, and our pre-antigen coated ELISA plates can be preserved at 4 °C until at least 6 months.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.1186/s12917-019-2123-2DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC6852973PMC
November 2019

Total serum protein reference value as a clinical diagnostic index of equine proliferative enteropathy.

J Equine Sci 2019 Sep 2;30(3):63-67. Epub 2019 Oct 2.

Department of Veterinary Sciences, Faculty of Agriculture, University of Miyazaki, Miyazaki 889-2192, Japan.

Equine proliferative enteropathy (EPE) caused by Lawsonia intracellularis is characterized by hypoproteinemia. There are currently no reliable reports that provide a reference value for the total serum protein (TP) concentration to clinically diagnose EPE. The objective of this study was to statistically determine the reference value. Feces and sera of 99 foals with EPE-like clinical signs and of 35 healthy foals were obtained. The samples were used for specific-gene detection of L. intracellularis, TP measurement, and specific-antibody detection against L. intracellularis. Based on these results, the optimal reference value for the TP concentration as a clinical diagnostic index of EPE was found to be ≤ 4.8 g/dl. This clinical diagnostic index will provide an effective approach for diagnosing EPE.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.1294/jes.30.63DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC6773620PMC
September 2019

Meteorological factors affecting the risk of transmission of HPAI in Miyazaki, Japan.

Vet Rec Open 2019 8;6(1):e000341. Epub 2019 Sep 8.

Faculty of Agriculture, University of Miyazaki, Miyazaki, Japan.

Highly pathogenic avian influenza (HPAI) outbreaks engender a severe economic impact on the poultry industry and public health. Migratory waterfowl are considered the natural hosts of HPAI virus, and HPAI viruses are known to be transmitted over long distances during seasonal bird migration. Bird migration is greatly affected by the weather. Many studies have shown the relationship between either autumn or spring bird migration and climate. However, few studies have shown the relationship between annual bird migration and annual weather. This study aimed to establish a model for the number of migratory waterfowl involved in HPAI virus transmission based on meteorological data. From 136 species of waterfowl that were observed at Futatsudate in Miyazaki, Japan, from 2008 to 2016, we selected potential high-risk species that could introduce the HPAI virus into Miyazaki and defined them as 'risky birds'. We also performed cluster analysis to select meteorological factors. We then analysed the meteorological data and the total number of risky birds using a generalised linear mixed model. We selected 10 species as risky birds: Mallard (), Northern pintail (), Eurasian wigeon (), Eurasian teal (), Common pochard (), Eurasian coot (), Northern shoveler (), Common shelduck (), Tufted duck () and Herring gull (). We succeeded in clustering 35 meteorological factors into four clusters and identified three meteorological factors associated with their migration: (1) the average daily maximum temperature; (2) the mean value of global solar radiation and (3) the maximum daily precipitation. We thus demonstrated the relationship between the number of risky birds and meteorological data. The dynamics of migratory waterfowl was relevant to the risk of an HPAI outbreak, and our data could contribute to cost and time savings in strengthening preventive measures against epidemics.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.1136/vetreco-2019-000341DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC6746539PMC
September 2019

Slaughterhouse survey for detection of bovine viral diarrhea infection among beef cattle in Kyushu, Japan.

J Vet Med Sci 2019 Oct 5;81(10):1450-1454. Epub 2019 Aug 5.

Department of Veterinary Science, Faculty of Agriculture, University of Miyazaki, Miyazaki 889-2192, Japan.

Bovine viral diarrhea virus (BVDV) footprint has spread across the globe and is responsible for one of the most economically important diseases in cattle. In Japan, some regional surveillance and preventive measures to control bovine viral diarrhea (BVD) have been implemented. However, BVDV infection is poorly understood in cattle industries, and there is no systematic BVD surveillance system and control program. Kyushu is the center for raising beef cattle in Japan. Therefore, this study aimed to determine the BVDV infection using a slaughterhouse survey among beef cattle in Kyushu, Japan. A total of 1,075 blood samples were collected at two regional slaughterhouses in Miyazaki prefecture from December 2015 to June 2016. Antigen ELISA was used for detection of BVDV antigen in blood samples. Two samples showed positive results (2/1,075; 0.18%). BVDV RNA was extracted from positive blood samples; the sequence was determined and analyzed by the neighbor-joining method for construction of the phylogenetic tree. Phylogenetic analysis based on the 5'-UTR revealed that the two positive samples were grouped into the same subtype BVDV-1b in the BVDV-1 genotype, but the infected cattle belonged to two different farms. In conclusion, this is the first study to identify the presence of BVDV in a slaughterhouse survey in Kyushu. These findings suggest that a slaughterhouse survey is a useful tool for developing a surveillance system for monitoring infectious diseases in cattle.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.1292/jvms.19-0045DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC6863731PMC
October 2019

Effect of intervention practices to control the porcine epidemic diarrhea (PED) outbreak during the first epidemic year (2013-2014) on time to absence of clinical signs and the number of dead piglets per sow in Japan.

Prev Vet Med 2019 Aug 18;169:104710. Epub 2019 Jun 18.

Center for Animal Disease Control, University of Miyazaki, Miyazaki, Japan; Department of Animal and Grassland Sciences, Faculty of Agriculture, University of Miyazaki, Miyazaki, Japan. Electronic address:

Porcine epidemic diarrhea (PED) is an emerging and/or re-emerging disease of pigs in several countries, with high morbidity and mortality in suckling piglets. Farms affected with PED perform various intervention practices to control and/or eliminate the PED virus. The objectives of the present study were to assess the effect of biosecurity measures and intervention practices to control PED on time to absence of clinical signs (TAC) and number of dead suckling piglets during TAC. A questionnaire was administered to 120-PED affected farms located across Japan between 2013, when the first case was reported in Japan, and 2014. Farms were asked to provide information on farm characteristics and internal or external biosecurity measures during PED outbreak, as well as on intervention practices to control PED. The TAC was defined as the number of days from the date that clinical PED signs appeared to the date that clinical PED signs disappeared. The number of dead piglets per sow (DP/S) was calculated as the number of dead suckling piglets during TAC divided by the sow inventory. Regarding the effect of biosecurity measures during PED outbreak on TAC and DP/S, longer TAC was observed in Actinobacillus pleuropneumoniae-positive farms and farms outsourcing pig transport to the slaughterhouse (p <  0.05). In addition, farms with divided truck entrances had lower DP/S than those without divided entrances (p <  0.05).Regarding the effect of intervention practices to control PED on TAC and DP/S, farms that performed feedback at 2 weeks or later after PED outbreak had longer TAC and higher DP/S than other farms (p <  0.05). Farms that fixed the hours staff worked in farrowing barn had lower DP/S than the other farms (p <  0.05). In conclusion, variables associated with long TAC were Actinobacillus pleuropneumoniae -positive farms, farms outsourcing pig transport to the slaughterhouse, and farms performing feedback at 2 week or later after PED outbreak. Additionally, those associated with high DP/S were farms without divided entrances, farms without a fixed hours worked in the barn, and farms that performed feedback at 2 week or later after PED outbreak.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.1016/j.prevetmed.2019.104710DOI Listing
August 2019

Laparoscopic decision-making concerning the repair area for traumatic abdominal wall pseudohernia: A case report.

Asian J Endosc Surg 2020 Apr 12;13(2):234-237. Epub 2019 Jun 12.

Department of Surgery, Sendai City Hospital, Sendai, Japan.

Laparoscopic decision-making may be useful for accurately determining the repair area when treating abdominal wall pseudohernia. A 31-year-old man was admitted with a pelvic ring fracture after a traffic accident and underwent orthopedic surgery. Five months after surgery, the patient developed a lower abdominal protrusion. CT revealed abdominal wall bulging and thinning of the abdominal muscle but no musculofascial defects, suggesting a pseudohernia. We reconstructed the abdominal wall and inserted a mesh. Because there was no musculofascial defect, it was difficult to discern the accurate repair area. We used laparoscopy to determine the repair area, which was recognized thanks to illumination transmitted through the abdominal wall. We were able to determine the appropriate size and placement of the mesh, which enabled us to repair the abdominal pseudohernia.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.1111/ases.12725DOI Listing
April 2020

The implementation of cattle market closure strategies to mitigate the foot-and-mouth disease epidemics: A contact modeling approach.

Res Vet Sci 2018 Dec 11;121:76-84. Epub 2018 Oct 11.

Department of Veterinary Science, Faculty of Agriculture, University of Miyazaki, Miyazaki, Japan; Center for Animal Disease Control, University of Miyazaki, Miyazaki, Japan.

Foot-and-mouth disease (FMD) is one of the most endemic diseases in livestock worldwide. The disease occurrence generally results in a huge economic impact. The virus may distribute across countries or even continents along the contact network of animal movements. The present study, therefore, aimed to explore a cattle movement network originated in Tak, a Thailand-Myanmar bordered province and to demonstrate how FMDV spread among the nodes of market, source and destination. Subsequently, we examined the effectiveness of market closure intervention. The market-market (M-M) network was constructed to highlight the inter-market connections and the FMDV was modeled to spread along the trade chain. Four market closure scenarios based on rapidness and duration of implementation were examined. Our results indicate that two of the three major markets located in the province were highly connected and a strongly connected component was identified. The intra-provincial animal movements, which were currently overlooked, should be moved into sights as most of the high-risk sources for FMD epidemics were recognized in a close proximity to the cattle markets. Simultaneously, remote destinations across the country were identified. The inter-provincial animal movement control must be strengthened once FMD outbreak is notified. Based on our simulations, closing markets with low inter-market connectivity may not prevent the spread of FMDV. A selective market closure strategy targeting highly connected markets together with cattle trader tracking system was an alternative approach. However, socio-economic consequences regarding this intervention must be considered.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.1016/j.rvsc.2018.10.007DOI Listing
December 2018

Detection of neutralizing antibody against porcine epidemic diarrhea virus in subclinically infected finishing pigs.

J Vet Med Sci 2018 Nov 2;80(11):1782-1786. Epub 2018 Oct 2.

Department of Veterinary Science, Faculty of Agriculture, University of Miyazaki, Miyazaki 889-2192, Japan.

The purpose of this study was to detect porcine epidemic diarrhea virus (PEDV) subclinically infected pigs shipped from non-case farms to slaughterhouses. Systematic sampling was conducted at two slaughterhouses. A total of 1,556 blood samples were collected from 80 case and non-case farms from pigs over 6 months old. Blood samples were centrifuged to obtain sera. Serial serum dilutions were subjected to serological examination for PEDV presence using Neutralization test (NT). The cut-off titer was set at titer of 1:2 dilution and farms with at least one positive sample in duplicate were classified as PED-positive farms. Several non-case farms (9.4%, 6/64) and 100% (16/16) of the case farms were indeed positive for PEDV. The proportion of seropositive animals from case farms was 63.7%, significantly different from that of non-case farms (4.3%, P<0.05). In both case and non-case farms, the proportion of seropositive animals in farrow-to-finish farms was significantly higher than in wean-to-finish farms (P<0.05). Seropositive animals in non-case farms were detected by NT in a sero-survey by sampling at slaughterhouses. Therefore, subclinically infected pigs should be considered prior to shipment.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.1292/jvms.18-0132DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC6261828PMC
November 2018

Novel recombinant feline interferon carrying N-glycans with reduced allergy risk produced by a transgenic silkworm system.

BMC Vet Res 2018 Aug 31;14(1):260. Epub 2018 Aug 31.

Innovation Center, Nippon Flour Mills Co., Ltd., 5-1-3 Midorigaoka, Atsugi, Kanagawa, 243-0041, Japan.

Background: The generation of recombinant proteins for commercialisation must be cost-effective. Despite the cost-effective production of recombinant feline interferon (rFeIFN) by a baculovirus expression system, this rFeIFN carries insect-type N-glycans, with core α 1,3 fucosyl residues that act as potential allergens. An alternative method of production may yield recombinant glycoproteins with reduced antigenicity.

Results: A cDNA clone encoding the fifteenth subtype of FeIFN-α (FeIFN-α15) was isolated from a Japanese domestic cat. This clone encoded a protein of 189 amino acids with a molecular mass of 21.1 kDa. The rFeIFN-α15 was expressed using a transgenic silkworm system, which was expected to yield an N-glycan structure with reduced antigenicity compared with the protein produced by the baculovirus system. The resulting rFeIFN-α15 accumulated in the sericin layer of silk fibres and was easily extracted and purified by column chromatography. The N-terminal amino acid sequence of purified rFeIFN-α15 was identical to the mature form of natural sequence. Moreover, its N-glycans did not include detectable core α 1,3 fucosyl residues. Its anti-vesicular stomatitis virus activity (2.6 × 10 units/mg protein) was comparable to that of the baculovirus-expressed rFeIFN.

Conclusions: The lower allergy risk of rFeIFN produced by the transgenic silkworm system than by the baculovirus expression system is due to the former lacking core α 1,3 fucosyl residues in its N-glycans. The rFeIFN-α15 produced by the transgenic silkworm system may be a prospective candidate for the next generation of rFeIFN in veterinary medicine.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.1186/s12917-018-1584-zDOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC6119277PMC
August 2018

Real-time decision-making during emergency disease outbreaks.

PLoS Comput Biol 2018 07 24;14(7):e1006202. Epub 2018 Jul 24.

Department of Life Sciences, University of Warwick, Coventry, United Kingdom.

In the event of a new infectious disease outbreak, mathematical and simulation models are commonly used to inform policy by evaluating which control strategies will minimize the impact of the epidemic. In the early stages of such outbreaks, substantial parameter uncertainty may limit the ability of models to provide accurate predictions, and policymakers do not have the luxury of waiting for data to alleviate this state of uncertainty. For policymakers, however, it is the selection of the optimal control intervention in the face of uncertainty, rather than accuracy of model predictions, that is the measure of success that counts. We simulate the process of real-time decision-making by fitting an epidemic model to observed, spatially-explicit, infection data at weekly intervals throughout two historical outbreaks of foot-and-mouth disease, UK in 2001 and Miyazaki, Japan in 2010, and compare forward simulations of the impact of switching to an alternative control intervention at the time point in question. These are compared to policy recommendations generated in hindsight using data from the entire outbreak, thereby comparing the best we could have done at the time with the best we could have done in retrospect. Our results show that the control policy that would have been chosen using all the data is also identified from an early stage in an outbreak using only the available data, despite high variability in projections of epidemic size. Critically, we find that it is an improved understanding of the locations of infected farms, rather than improved estimates of transmission parameters, that drives improved prediction of the relative performance of control interventions. However, the ability to estimate undetected infectious premises is a function of uncertainty in the transmission parameters. Here, we demonstrate the need for both real-time model fitting and generating projections to evaluate alternative control interventions throughout an outbreak. Our results highlight the use of using models at outbreak onset to inform policy and the importance of state-dependent interventions that adapt in response to additional information throughout an outbreak.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.1371/journal.pcbi.1006202DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC6075790PMC
July 2018

Bovine respiratory syncytial virus infection enhances Pasteurella multocida adherence on respiratory epithelial cells.

Vet Microbiol 2018 Jul 30;220:33-38. Epub 2018 Apr 30.

Department of Veterinary Science, Faculty of Agriculture, University of Miyazaki, Miyazaki, Japan; Center for Animal Disease Control, University of Miyazaki, Miyazaki, Japan. Electronic address:

Primary infection with bovine respiratory syncytial virus (BRSV) predisposes cattle to secondary infection with bacteria that cause bovine respiratory disease complex (BRDC). However, the interaction between BRSV and bacteria is unclear. This in vitro study examined the adherence of Pasteurella multocida (PM) to BRSV-infected cells was assessed in colony forming unit assays, by flow cytometry analysis, and by indirect immunofluorescence analysis (IFA) of epithelial cells (A549, HEp-2, and MDBK). An in vitro model based on infection of BRSV-infected epithelial cells revealed that PM adherence to BRSV-infected cells was 2- to 8-fold higher than uninfected cells. This was confirmed by flow cytometry analysis and IFA. Epithelial cell expression of mRNA encoding cytokines and chemokines increased after exposure to PM, but increased further after co-infection with BRSV and PM. BRSV-mediated adherence of PM to epithelial cells may underlie the serious symptoms of BRDC.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.1016/j.vetmic.2018.04.031DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC7117154PMC
July 2018

Development of pooled testing system for porcine epidemic diarrhoea using real-time fluorescent reverse-transcription loop-mediated isothermal amplification assay.

BMC Vet Res 2018 May 29;14(1):172. Epub 2018 May 29.

Animal Infectious Disease and Prevention, Department of Veterinary Sciences, Faculty of Agriculture, University of Miyazaki, Miyazaki, Japan.

Background: Porcine epidemic diarrhoea (PED) is an emerging disease in pigs that causes massive economic losses in the swine industry, with high mortality in suckling piglets. Early identification of PED virus (PEDV)-infected herd through surveillance or monitoring strategies is necessary for mass control of PED. However, a common working diagnosis system involves identifying PEDV-infected animals individually, which is a costly and time-consuming approach. Given the above information, the thrusts of this study were to develop a real-time fluorescent reverse transcription loop-mediated isothermal amplification (RtF-RT-LAMP) assay and establish a pooled testing system using faecal sample to identify PEDV-infected herd.

Results: In this study, we developed an accurate, rapid, cost-effective, and simple RtF- RT-LAMP assay for detecting the PEDV genome targeting M gene. The pooled testing system using the RtF-RT-LAMP assay was optimized such that a pool of at least 15 individual faecal samples could be analysed.

Conclusions: The developed RtF-RT-LAMP assay in our study could support the design and implementation of large-scaled epidemiological surveys as well as active surveillance and monitoring programs for effective control of PED.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.1186/s12917-018-1498-9DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC5975689PMC
May 2018

Factors associated with farm-level infection of porcine epidemic diarrhea during the early phase of the epidemic in Japan in 2013 and 2014.

Prev Vet Med 2018 Feb 11;150:77-85. Epub 2017 Dec 11.

Veterinary Epidemiology Unit, School of Veterinary Medicine, Rakuno Gakuen University, 582, Bunkyodai-Midorimachi, Ebetsu, Hokkaido, Japan. Electronic address:

The objective of this study was to investigate factors that caused rapid spread during the early phase of the porcine epidemic diarrhea (PED) epidemic in Japan in 2013 and 2014. Anonymized datasets from all pig farms were provided by Kagoshima (709 farms) and Miyazaki Prefectures (506 farms). Semi-parametric survival analysis was conducted using the first 180 days from the first case on December 3, 2013 in Kagoshima Prefecture. To compare the hazard between different farm management types, univariable survival analysis was conducted. As farm sizes varied among different farm types, bivariable survival analysis was conducted for farm size categories and farm density per km for each management type. A case-control study using a postal questionnaire survey was conducted in September 2014, and risk factor analysis was performed using generalized linear models with binomial errors. The hazard was significantly higher in farrow-to-finish farms than fattening farms [hazard ratio (HR) = 1.6, p < 0.01], but was not significantly different between reproduction and fattening farms (HR = 1.3, p = 0.16). In separate bivariable survival analyses for each farm type, large- and middle-scale farms had higher hazard than small-scale farms in fattening (HR = 5.8 and 2.6, respectively, both p < 0.01) and reproduction farms (HR = 4.0 and 3.6, respectively, both p < 0.01). In farrow-to-finish farms, large-scale farms had higher hazard than small-scale farms (HR = 2.8, p < 0.01), and higher farm density per km was also a risk factor (HR = 7.6, p < 0.01). In the case-control study, questionnaires were returned from 78 PED virus-infected and 91 non-infected farms. The overall response rate was 34%. Risk factors of the final model were occurrence of porcine reproductive and respiratory syndrome in the past 5 years [odds ratio (OR) = 1.97, 95% confidence interval (CI): 0.97-4.00, p = 0.054], use of a common compost station (OR = 2.51, 95%CI: 1.08-5.83, p = 0.03), and use of a pig excrement disposal service (OR = 2.64, 95%CI: 1.05-6.63, p = 0.04). High hazard in farrow-to-finish farms suggested transmission from slaughterhouses to susceptible suckling piglets. Hazard associated with large-scale farms and high density might be due to frequent vehicle entrance and transmission by roads. Improvement of farm hygiene management and avoidance of risky practices associated with contact with pig excrement were keys in preventing invasion of PED virus to a farm.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.1016/j.prevetmed.2017.12.008DOI Listing
February 2018

New hematological key for bovine leukemia virus-infected Japanese Black cattle.

J Vet Med Sci 2018 Feb 22;80(2):316-319. Epub 2018 Jan 22.

Center for Animal Disease Control, University of Miyazaki, 1-1 Gakuen-Kibanadai-Nishi, Miyazaki 889-2192, Japan.

The European Community's (EC) Key, which is also called Bendixen's Key, is a well-established bovine leukemia virus (BLV) diagnostic method that classifies cattle according to the absolute lymphocyte count and age. The EC Key was originally designed for dairy cattle and is not necessarily suitable for Japanese Black (JB) beef cattle. This study revealed the lymphocyte counts in the BLV-free and -infected JB cattle were significantly lower than those in the Holstein cattle. Therefore, applying the EC Key to JB cattle could result in a large number of undetected BLV-infected cattle. Our proposed hematological key, which was designed for JB cattle, improves the detection of BLV-infected cattle by approximately 20%. We believe that this study could help promote BLV control.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.1292/jvms.17-0455DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC5836770PMC
February 2018

High Prevalence of Campylobacter in Broiler Flocks is a Crucial Factor for Frequency of Food Poisoning in Humans.

Jpn J Infect Dis 2017 Nov 11;70(6):691-692. Epub 2017 Sep 11.

Graduate School of Medicine and Veterinary Medicine, University of Miyazaki.

View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.7883/yoken.JJID.2017.132DOI Listing
November 2017

Cattle with the BoLA class II DRB3*0902 allele have significantly lower bovine leukemia proviral loads.

J Vet Med Sci 2017 Sep 28;79(9):1552-1555. Epub 2017 Jul 28.

Laboratory of Animal Infectious Disease and Prevention, Department of Veterinary Sciences, Faculty of Agriculture, University of Miyazaki, 1-1 Gakuen-Kibanadai-Nishi, Miyazaki 889-2192, Japan.

The bovine MHC (BoLA) class II DRB3 alleles are associated with polyclonal expansion of lymphocytes caused by bovine leukemia virus (BLV) infection in cattle. To examine whether the DRB3*0902 allele, one of the resistance-associated alleles, is associated with the proviral load, we measured BLV proviral load of BLV-infected cattle and clarified their DRB3 alleles. Fifty-seven animals with DRB3*0902 were identified out of 835 BLV-infected cattle and had significantly lower proviral load (P<0.000001) compared with the rest of the infected animals, in both Japanese Black and Holstein cattle. This result strongly indicates that the BoLA class II DRA/DRB3*0902 molecule plays an important immunological role in suppressing viral replication, resulting in resistance to the disease progression.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.1292/jvms.16-0601DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC5627326PMC
September 2017

Spatial dynamics of porcine epidemic diarrhea (PED) spread in the southern Kyushu, Japan.

Prev Vet Med 2017 Sep 3;144:81-88. Epub 2017 Jun 3.

Department of Veterinary Population Medicine, College of Veterinary Medicine, University of Minnesota, MN, USA.

Porcine epidemic diarrhea (PED) was detected for the first time in seven years in Japan in October 2013 in Okinawa Prefecture. By December 2013, PED had spread into Miyazaki and Kagoshima Prefectures in the southern part of Kyushu, one of the regions with the highest farm density in the country. The objective of the study here was to assess the spatial dynamics of PED spread during the 8 months of the epidemic in the southern part of Kyushu between December 2013, the month observed first case in the studied region, and July 2014. Information on location and capacity of all farms in the prefectures (n=1269) was obtained from a government database containing demographic information for livestock producers. Additionally, data on PED detection (positive or negative) was obtained from the regional Livestock Hygiene Service Center. The Cuzick-Edwards (CE) test, the Knox test, the directional test, and the permutation model of the scan statistic were used to assess the spatio-temporal distribution of the epidemic. PED cumulative farm level incidence was 19.5% (248/1269) through the study period. The highest density of positive farms was observed in the most farm-populated areas of the prefecture. The CE test revealed an extensive degree of spatial clustering, with clustering of positive sites being significant (P<0.01) up to the 35th level of neighborhood (approximately 5km in the studied data). The observed-to-expected ratio of cases was maximized at short spatio-temporal distances, with values of the observed-to-expected ratio of cases maximized when the thresholds were set at 2km and 10days, respectively. A significant (P<0.01) direction of spread was detected towards the northeastern direction. The permutation model detected five significant (P<0.01) clusters occurring at different stages of the epidemic wave. The strong spatio-temporal clustering of PED-infected farms during the first 6 months of the epidemic in the southern part of Kyushu is consistent with results obtained elsewhere and demonstrates the rapid spread of the virus in naïve populations.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.1016/j.prevetmed.2017.05.025DOI Listing
September 2017

Phylogenetic analysis of env gene of bovine leukemia virus strains spread in Miyazaki prefecture, Japan.

J Vet Med Sci 2017 May 23;79(5):912-916. Epub 2017 Mar 23.

Laboratory of Animal Infectious Disease and Prevention, Department of Veterinary Sciences, Faculty of Agriculture, University of Miyazaki, 1-1 Gakuen-Kibanadai-Nishi, Miyazaki 889-2192, Japan.

To understand how the latest dominant bovine leukemia virus (BLV) strains were introduced and spread in the Miyazaki prefecture, we collected blood samples from 3 geographic areas (north, central and south) and carried out sequence analysis of the BLV env gene. Two genotypes, genotype I, and III, were identified and the majority of the strains belonged to genotype I (71/74). To clarify a route of BLV introduction, we divided the strains into 20 subgenotypes based on their nucleotide sequences and performed phylogenetic analysis. Our study indicated that common BLV strains were comparatively evenly distributed even in the area, where the farmers have not introduced cattle from other areas and the cattle have limited exposure to BLV infection in grazing fields.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.1292/jvms.17-0055DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC5447981PMC
May 2017