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Ip YCA, Tan A, Ong J, Fernandez CJ, Lau C, Wong WK, Chang SF, Yap HH, Er KBH. Anthropogenic Transmission of SARS-CoV-2 from Humans to Lions, Singapore, 2021. Emerg Infect Dis 2023; 29:2550-2553. [PMID: 37885046 PMCID: PMC10683833 DOI: 10.3201/eid2912.221916] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/28/2023] Open
Abstract
In Singapore, 10 captive lions tested positive for SARS-CoV-2 by real-time PCR. Genomic analyses of nanopore sequencing confirmed human-to-animal transmission of the SARS-CoV-2 Delta variant. Viral genomes from the lions and zookeeper shared a unique spike protein substitution, S:A1016V. Widespread SARS-CoV-2 transmission among humans can increase the likelihood of anthroponosis.
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Koh EY, Tan AKS, Yeo D, Lau C, Tan LY, Ng OW, Ong J, Chong S, Toh S, Chen J, Wong WK, Tan BZY, He-Lee C, Heng ZP, Liang I, Fernandez CJ, Chang SF, Er KBH. Detection of African Swine Fever Virus from Wild Boar, Singapore, 2023. Emerg Infect Dis 2023; 29:2580-2583. [PMID: 37708842 PMCID: PMC10683832 DOI: 10.3201/eid2912.230966] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 09/16/2023] Open
Abstract
We detected African swine fever virus (ASFV) from a wild boar in Singapore. In <72 hours, we confirmed and reported ASFV p72 genotype II, CD2v serogroup 8, and IGR-II variant by using a combination of real-time PCR and whole-genome sequencing. Continued biosurveillance will be needed to monitor ASFV in Singapore.
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Chong SQY, Yeo D, Aidil NI, Ong JLY, Chan AHJ, Fernandez CJ, Lim BTM, Khoo MDY, Wong AMS, Chang SF, Yap HH. Detection of a novel Babesia sp. in Amblyomma javanense, an ectoparasite of Sunda pangolins. Parasit Vectors 2023; 16:432. [PMID: 37993967 PMCID: PMC10664631 DOI: 10.1186/s13071-023-06040-4] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/08/2023] [Accepted: 10/31/2023] [Indexed: 11/24/2023] Open
Abstract
BACKGROUND Babesia is a protozoal, tick-borne parasite that can cause life-threatening disease in humans, wildlife and domestic animals worldwide. However, in Southeast Asia, little is known about the prevalence and diversity of Babesia species present in wildlife and the tick vectors responsible for its transmission. Recently, a novel Babesia species was reported in confiscated Sunda pangolins (Manis javanica) in Thailand. To investigate the presence of this parasite in Singapore, we conducted a molecular survey of Babesia spp. in free-roaming Sunda pangolins and their main ectoparasite, the Amblyomma javanense tick. METHODS Ticks and tissue samples were opportunistically collected from live and dead Sunda pangolins and screened using a PCR assay targeting the 18S rRNA gene of Babesia spp. DNA barcoding of the cytochrome oxidase subunit I (COI) mitochondrial gene was used to confirm the species of ticks that were Babesia positive. RESULTS A total of 296 ticks and 40 tissue samples were obtained from 21 Sunda pangolins throughout the 1-year study period. Babesia DNA was detected in five A. javanense ticks (minimum infection rate = 1.7%) and in nine different pangolins (52.9%) located across the country. Phylogenetic analysis revealed that the Babesia 18S sequences obtained from these samples grouped into a single monophyletic clade together with those derived from Sunda pangolins in Thailand and that this evolutionarily distinct species is basal to the Babesia sensu stricto clade, which encompasses a range of Babesia species that infect both domestic and wildlife vertebrate hosts. CONCLUSIONS This is the first report documenting the detection of a Babesia species in A. javanense ticks, the main ectoparasite of Sunda pangolins. While our results showed that A. javanense can carry this novel Babesia sp., additional confirmatory studies are required to demonstrate vector competency. Further studies are also necessary to investigate the role of other transmission pathways given the low infection rate of ticks in relation to the high infection rate of Sunda pangolins. Although it appears that this novel Babesia sp. is of little to no pathogenicity to Sunda pangolins, its potential to cause disease in other animals or humans cannot be ruled out.
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Affiliation(s)
- Stacy Q Y Chong
- Animal and Veterinary Service, National Parks Board (NParks), 1 Cluny Road, Singapore Botanic Gardens, Singapore, 259569, Singapore.
| | - Darren Yeo
- Animal and Veterinary Service, National Parks Board (NParks), 1 Cluny Road, Singapore Botanic Gardens, Singapore, 259569, Singapore
| | - Nur Insyirah Aidil
- Animal and Veterinary Service, National Parks Board (NParks), 1 Cluny Road, Singapore Botanic Gardens, Singapore, 259569, Singapore
| | - Jasmine L Y Ong
- Animal and Veterinary Service, National Parks Board (NParks), 1 Cluny Road, Singapore Botanic Gardens, Singapore, 259569, Singapore
| | - Amy H J Chan
- Animal and Veterinary Service, National Parks Board (NParks), 1 Cluny Road, Singapore Botanic Gardens, Singapore, 259569, Singapore
| | - Charlene Judith Fernandez
- Animal and Veterinary Service, National Parks Board (NParks), 1 Cluny Road, Singapore Botanic Gardens, Singapore, 259569, Singapore
| | - Bryan T M Lim
- Wildlife Management, National Parks Board (NParks), 1 Cluny Road, Singapore Botanic Gardens, Singapore, 259569, Singapore
| | - Max D Y Khoo
- Wildlife Management, National Parks Board (NParks), 1 Cluny Road, Singapore Botanic Gardens, Singapore, 259569, Singapore
| | - Anna M S Wong
- Wildlife Management, National Parks Board (NParks), 1 Cluny Road, Singapore Botanic Gardens, Singapore, 259569, Singapore
| | - Siow Foong Chang
- Animal and Veterinary Service, National Parks Board (NParks), 1 Cluny Road, Singapore Botanic Gardens, Singapore, 259569, Singapore
| | - Him Hoo Yap
- Animal and Veterinary Service, National Parks Board (NParks), 1 Cluny Road, Singapore Botanic Gardens, Singapore, 259569, Singapore
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Chen A, Boulay M, Chong S, Ho K, Chan A, Ong J, Fernandez CJ, Chang SF, Yap HH. Suspected clinical toxoplasmosis in a 12-week-old puppy in Singapore. BMC Vet Res 2023; 19:110. [PMID: 37542292 PMCID: PMC10401807 DOI: 10.1186/s12917-023-03674-5] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/10/2023] [Accepted: 07/24/2023] [Indexed: 08/06/2023] Open
Abstract
BACKGROUND Toxoplasma gondii is traditionally known as a parasite of felids, with possible infection in intermediate hosts such as dogs and humans, and thus a disease of public health significance. Published data on the prevalence of toxoplasmosis in dogs and cats in Singapore is scanty, and this paper documents a suspect clinical case of toxoplasmosis in a free-roaming puppy trapped from an offshore island of Singapore. CASE PRESENTATION A 12-week-old puppy presented with hindlimb weakness and sarcopenia, with rapidly progressing ascending paralysis and respiratory distress, one week after trapping. Toxoplasmosis was suspected after indirect fluorescence antibody testing (IFAT) revealed anti-T. gondii antibodies. The puppy responded quickly to clindamycin treatment and was discharged from hospital after 10 days. CONCLUSION While rare and undocumented, veterinary clinicians in Singapore are advised to also include toxoplasmosis infection as a differential diagnosis in dogs presenting with similar clinical signs. This is especially so for dogs which have access to the outdoors.
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Affiliation(s)
- Audrey Chen
- Centre for Animal Rehabilitation, Animal & Veterinary Service, Animal Management Centre, National Parks Board, 57 Sungei Tengah Road, 699013, Singapore, Singapore.
| | - Max Boulay
- Westside Emergency, 41 Eng Kong Terrace, 599013, Singapore, Singapore
| | - Stacy Chong
- Centre for Animal & Veterinary Sciences, Animal & Plant Health Centre, Animal & Veterinary Service, National Parks Board, 6 Perahu Road, 718827, Singapore, Singapore, Singapore
| | - Kelvin Ho
- Biorisk and Biosurveillance, Animal & Veterinary Service, National Parks Board, JEM Office Tower, 52 Jurong Gateway Road, 608550, Singapore, Singapore, Singapore
| | - Amy Chan
- Centre for Animal & Veterinary Sciences, Animal & Plant Health Centre, Animal & Veterinary Service, National Parks Board, 6 Perahu Road, 718827, Singapore, Singapore, Singapore
| | - Jasmine Ong
- Centre for Animal & Veterinary Sciences, Animal & Plant Health Centre, Animal & Veterinary Service, National Parks Board, 6 Perahu Road, 718827, Singapore, Singapore, Singapore
| | - Charlene Judith Fernandez
- Centre for Animal & Veterinary Sciences, Animal & Plant Health Centre, Animal & Veterinary Service, National Parks Board, 6 Perahu Road, 718827, Singapore, Singapore, Singapore
| | - Siow Foong Chang
- Professional & Scientific Services, Animal & Veterinary Service, National Parks Board, JEM Office Tower, 52 Jurong Gateway Road, 608550, Singapore, Singapore, Singapore
| | - Him Hoo Yap
- Animal & Veterinary Service, National Parks Board, Singapore Botanic Gardens, 1 Cluny Road, 259569, Singapore, Singapore
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5
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Koh EY, Ong J, Wang Y, Toh X, Fernandez CJ, Huangfu T, Hall RN, Toh S, Lim K, Sng W, Lim HP, Ho K, Chang SF, Yap HH. Rabbit haemorrhagic disease virus 2 from Singapore 2020 outbreak revealed an Australian recombinant variant. Virus Evol 2023; 9:vead029. [PMID: 37207001 PMCID: PMC10190043 DOI: 10.1093/ve/vead029] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/29/2022] [Revised: 03/25/2023] [Accepted: 04/27/2023] [Indexed: 05/21/2023] Open
Abstract
Rabbit haemorrhagic disease (RHD) is a significant and debilitating viral disease affecting lagomorphs. In September 2020, Singapore reported its first cases of RHD virus (RHDV) infection in domesticated rabbits. The initial findings reported that the outbreak strain belonged to genotype GI.2 (RHDV2/RHDVb), and epidemiological investigations could not identify the definitive source of the virus origin. Further recombination detection and phylogenetic analyses of the Singapore outbreak strain revealed that the RHDV was a GI.2 structural (S)/GI.4 non-structural (NS) recombinant variant. Sequence analyses on the National Centre for Biotechnology Information (NCBI) database showed high homology to recently emerged Australian variants, which were prevalent in local Australian lagomorph populations since 2017. Time-structured and phylogeographic analyses for the S and NS genes revealed a close genetic relationship between the Singapore RHDV strain and the Australian RHDV variants. More thorough epidemiological inquiries are necessary to ascertain how an Australian RHDV was introduced into the Singapore rabbit population, and opportune development of RHDV diagnostics and vaccines will be important to safeguard lagomorphs from future RHDV infection and disease management.
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Affiliation(s)
| | - Jasmine Ong
- Centre for Animal & Veterinary Sciences, Professional and Scientific Services, Animal and Veterinary Service, National Parks Board (NParks), 1 Cluny Road, Singapore Botanic Gardens 259569, Singapore
| | - Yifan Wang
- Centre for Animal & Veterinary Sciences, Professional and Scientific Services, Animal and Veterinary Service, National Parks Board (NParks), 1 Cluny Road, Singapore Botanic Gardens 259569, Singapore
| | - Xinyu Toh
- Centre for Animal & Veterinary Sciences, Professional and Scientific Services, Animal and Veterinary Service, National Parks Board (NParks), 1 Cluny Road, Singapore Botanic Gardens 259569, Singapore
| | - Charlene Judith Fernandez
- Centre for Animal & Veterinary Sciences, Professional and Scientific Services, Animal and Veterinary Service, National Parks Board (NParks), 1 Cluny Road, Singapore Botanic Gardens 259569, Singapore
| | - Taoqi Huangfu
- Centre for Animal & Veterinary Sciences, Professional and Scientific Services, Animal and Veterinary Service, National Parks Board (NParks), 1 Cluny Road, Singapore Botanic Gardens 259569, Singapore
| | | | - Steffie Toh
- Centre for Animal & Veterinary Sciences, Professional and Scientific Services, Animal and Veterinary Service, National Parks Board (NParks), 1 Cluny Road, Singapore Botanic Gardens 259569, Singapore
| | - Kelvin Lim
- Veterinary Health Management, Professional and Scientific Services, Animal and Veterinary Service, National Parks Board (NParks), 1 Cluny Road, Singapore Botanic Gardens 259569, Singapore
| | - Wendy Sng
- Veterinary Health Management, Professional and Scientific Services, Animal and Veterinary Service, National Parks Board (NParks), 1 Cluny Road, Singapore Botanic Gardens 259569, Singapore
| | - Hwee Ping Lim
- Veterinary Health Management, Professional and Scientific Services, Animal and Veterinary Service, National Parks Board (NParks), 1 Cluny Road, Singapore Botanic Gardens 259569, Singapore
| | - Kelvin Ho
- Veterinary Health Management, Professional and Scientific Services, Animal and Veterinary Service, National Parks Board (NParks), 1 Cluny Road, Singapore Botanic Gardens 259569, Singapore
| | - Siow Foong Chang
- Professional and Scientific Services, Animal and Veterinary Service, National Parks Board (NParks), 1 Cluny Road, Singapore Botanic Gardens 259569, Singapore
| | - Him Hoo Yap
- Animal and Veterinary Service, National Parks Board (NParks), 1 Cluny Road, Singapore Botanic Gardens 259569, Singapore
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Wang Y, Ong J, Ng OW, Songkasupa T, Koh EY, Wong JPS, Puangjinda K, Fernandez CJ, Huangfu T, Ng LC, Chang SF, Yap HH. Development of Differentiating Infected from Vaccinated Animals (DIVA) Real-Time PCR for African Horse Sickness Virus Serotype 1. Emerg Infect Dis 2022; 28:2446-2454. [PMID: 36417933 PMCID: PMC9707579 DOI: 10.3201/eid2812.220594] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/14/2022] Open
Abstract
African horse sickness (AHS) is a highly infectious and often fatal disease caused by 9 serotypes of the orbivirus African horse sickness virus (AHSV). In March 2020, an AHS outbreak was reported in Thailand in which AHSV serotype 1 was identified as the causative agent. Trivalent live attenuated vaccines serotype 1, 3, and 4 were used in a targeted vaccination campaign within a 50-km radius surrounding the infected cases, which promptly controlled the spread of the disease. However, AHS-like symptoms in vaccinated horses required laboratory diagnostic methods to differentiate infected horses from vaccinated horses, especially for postvaccination surveillance. We describe a real-time reverse transcription PCR-based assay for rapid characterization of the affecting field strain. The development and validation of this assay should imbue confidence in differentiating AHS-vaccinated horses from nonvaccinated horses. This method should be applied to determining the epidemiology of AHSV in future outbreaks.
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Lim K, Tan A, Ho K, Sng W, Lim HP, Chan C, Toh X, Ong J, Chang SF, Fernandez CJ. Resolution of rabbit haemorrhagic disease virus 2 (RHDV2; Lagovirus europeus GI.2) outbreak in Singapore. Transbound Emerg Dis 2021; 69:3077-3083. [PMID: 34480780 DOI: 10.1111/tbed.14312] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/14/2021] [Revised: 08/30/2021] [Accepted: 09/02/2021] [Indexed: 11/29/2022]
Abstract
Rabbit haemorrhagic disease (RHD) is a highly contagious viral disease affecting lagomorphs. The first documented cases of RHD in Singapore occurred in adult pet European rabbits in September 2020. Singapore subsequently declared the outbreak resolved in December 2020. Epidemiological investigations ruled out introductions via importation of infected rabbits and contaminated feed. The source could not be definitively determined. However, the findings suggested that the incident involved both inter- and intra-household transmission and veterinary clinic-household transmission. This incident demonstrated the importance of sustained application of biosecurity measures, epidemiological investigations including active case finding, control measures such as expedient vaccine dissemination and risk communications. It showed that even without a wild lagomorph population, an urbanized city-state like Singapore could still encounter emerging diseases such as RHD. Given its social impact on rabbit owners, the National Parks Board, Singapore and private veterinarians worked together to communicate with rabbit owners in order to urge them to adopt biosecurity measures and to address their concerns.
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Affiliation(s)
- Kelvin Lim
- Professional and Scientific Services, Animal and Veterinary Service, National Parks Board (NParks), Botanic Gardens, Singapore, Singapore
| | - Alwyn Tan
- Professional and Scientific Services, Animal and Veterinary Service, National Parks Board (NParks), Botanic Gardens, Singapore, Singapore
| | - Kelvin Ho
- Professional and Scientific Services, Animal and Veterinary Service, National Parks Board (NParks), Botanic Gardens, Singapore, Singapore
| | - Wendy Sng
- Professional and Scientific Services, Animal and Veterinary Service, National Parks Board (NParks), Botanic Gardens, Singapore, Singapore
| | - Hwee Ping Lim
- Professional and Scientific Services, Animal and Veterinary Service, National Parks Board (NParks), Botanic Gardens, Singapore, Singapore
| | - Cathy Chan
- The Animal Doctors Pte Ltd (Singapore), Singapore, Singapore
| | - Xinyu Toh
- Professional and Scientific Services, Animal and Veterinary Service, National Parks Board (NParks), Botanic Gardens, Singapore, Singapore
| | - Jasmine Ong
- Professional and Scientific Services, Animal and Veterinary Service, National Parks Board (NParks), Botanic Gardens, Singapore, Singapore
| | - Siow Foong Chang
- Professional and Scientific Services, Animal and Veterinary Service, National Parks Board (NParks), Botanic Gardens, Singapore, Singapore
| | - Charlene Judith Fernandez
- Professional and Scientific Services, Animal and Veterinary Service, National Parks Board (NParks), Botanic Gardens, Singapore, Singapore
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Toh X, Ong J, Chan C, Teo XH, Toh S, Fernandez CJ, Huangfu T. First detection of rabbit haemorrhagic disease virus (RHDV2) in Singapore. Transbound Emerg Dis 2021; 69:1521-1528. [PMID: 33892517 DOI: 10.1111/tbed.14116] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/16/2020] [Revised: 03/15/2021] [Accepted: 04/16/2021] [Indexed: 11/26/2022]
Abstract
Rabbit haemorrhagic disease (RHD) is a significant viral disease caused by infection with Rabbit haemorrhagic disease virus (RHDV). The first documented cases of RHDV in Singapore occurred in adult pet European rabbits (Oryctolagus cuniculus) in September 2020. Rabbits presented with acute hyporexia, lethargy, huddled posture, and varying degrees of pyrexia and tachypnoea. Clinical pathology consistently reflected markedly elevated alanine aminotransferase (ALT), aspartate aminotransferase (AST) and alkaline phosphatase (ALKP). Hepatic lobe torsion was ruled out using ultrasonography and colour Doppler studies in all patients. A total of 11 rabbits owned by 3 families were presented to the clinics; 8/11 rabbits died within 48 hr of presentation, while the remaining two rabbits had recovered after prolonged hospitalization and one rabbit was aclinical. Histopathology revealed acute, marked diffuse hepatocellular necrosis and degeneration, findings which were suggestive for RHDV infection and prompted the undertaking of further molecular diagnostics. Subsequent polymerase chain reaction of the liver samples detected RHDV RNA. Molecular characterization of viral genomes by whole genome sequencing revealed that the outbreak strain was of the genotype GI.2 (RHDV2/RHDVb). Nucleotide sequences of the VP60 gene were compared with various RHDV variants using phylogenetic analysis. The sample genome shared highest sequence identity with a GI.2-genotyped virus from GenBank (RHDV isolate Algarve 1 polyprotein and minor structural protein (VP10) genes, GenBank accession KF442961). The combination of clinical, histopathological, molecular and sequencing technologies enabled rapid detection and detailed genetic characterization of the RHDV virus causing the present outbreak for prompt implementation of disease control measures in Singapore. Further epidemiological investigations of potential virus introduction into Singapore are ongoing.
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Affiliation(s)
- Xinyu Toh
- Center for Animal & Veterinary Sciences, Professional and Scientific Services, Animal and Veterinary Service, National Parks Board (NParks), Singapore
| | - Jasmine Ong
- Center for Animal & Veterinary Sciences, Professional and Scientific Services, Animal and Veterinary Service, National Parks Board (NParks), Singapore
| | - Cathy Chan
- The Animal Doctors Pte Ltd (Singapore), Singapore
| | - Xuan Hui Teo
- Center for Animal & Veterinary Sciences, Professional and Scientific Services, Animal and Veterinary Service, National Parks Board (NParks), Singapore
| | - Steffie Toh
- Center for Animal & Veterinary Sciences, Professional and Scientific Services, Animal and Veterinary Service, National Parks Board (NParks), Singapore
| | - Charlene Judith Fernandez
- Center for Animal & Veterinary Sciences, Professional and Scientific Services, Animal and Veterinary Service, National Parks Board (NParks), Singapore
| | - Taoqi Huangfu
- Center for Animal & Veterinary Sciences, Professional and Scientific Services, Animal and Veterinary Service, National Parks Board (NParks), Singapore
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Toh X, Wang Y, Rajapakse MP, Lee B, Songkasupa T, Suwankitwat N, Kamlangdee A, Judith Fernandez C, Huangfu T. Use of nanopore sequencing to characterize african horse sickness virus (AHSV) from the African horse sickness outbreak in thailand in 2020. Transbound Emerg Dis 2021; 69:1010-1019. [PMID: 33682298 DOI: 10.1111/tbed.14056] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/04/2020] [Revised: 03/03/2021] [Accepted: 03/03/2021] [Indexed: 12/01/2022]
Abstract
African horse sickness (AHS) is a highly infectious and deadly disease despite availability of vaccines. Molecular characterization of African horse sickness virus (AHSV) detected from the March 2020 Thailand outbreak was carried out by whole-genome sequencing using Nanopore with a Sequence-Independent Single Primer Amplification (SISPA) approach. Nucleotide sequence of the whole genome was compared with closest matching AHSV strains using phylogenetic analyses and the AHSV-1 virus shared high sequence identity with isolates from the same outbreak. Substitution analysis revealed non-synonymous and synonymous substitutions in the VP2 gene as compared to circulating South African strains. The use of sequencing technologies, such as Nanopore with SISPA, has enabled rapid detection, identification and detailed genetic characterization of the AHS virus for informed decision-making and implementation of disease control measures. Active genetic information sharing has also allowed emergence of AHSV to be better monitored on a global basis.
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Affiliation(s)
- Xinyu Toh
- Center for Animal & Veterinary Sciences, Professional and Scientific Services, Animal and Veterinary Service, National Parks Board (NParks), Singapore
| | - Yifan Wang
- Center for Animal & Veterinary Sciences, Professional and Scientific Services, Animal and Veterinary Service, National Parks Board (NParks), Singapore
| | | | - Bernett Lee
- Singapore Immunology Network (SIgN), Agency for Science, Technology and Research (A*STAR), Singapore
| | - Tapanut Songkasupa
- Virology section, Department of Livestock Development, National Institute of Animal Health, Bangkok, Thailand
| | - Nutthakarn Suwankitwat
- Virology section, Department of Livestock Development, National Institute of Animal Health, Bangkok, Thailand
| | - Attapon Kamlangdee
- Faculty of Veterinary Medicine, Kasetsart university, Kamphaengsean, Thailand
| | - Charlene Judith Fernandez
- Center for Animal & Veterinary Sciences, Professional and Scientific Services, Animal and Veterinary Service, National Parks Board (NParks), Singapore
| | - Taoqi Huangfu
- Center for Animal & Veterinary Sciences, Professional and Scientific Services, Animal and Veterinary Service, National Parks Board (NParks), Singapore
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10
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Wang Y, Toh X, Ong J, Teo XH, Bay P, Fernandez CJ, Huangfu T. Serological prevalence and molecular characterization of hepatitis E virus in imported pigs in Singapore (2000-2019). Transbound Emerg Dis 2021; 69:286-296. [PMID: 33406320 DOI: 10.1111/tbed.13977] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/26/2020] [Revised: 12/28/2020] [Accepted: 01/03/2021] [Indexed: 12/25/2022]
Abstract
Hepatitis E is a significant liver disease caused by infection with hepatitis E virus (HEV). The risk factors for hepatitis E in developed countries include blood transfusion and ingestion of undercooked meat or meat products derived from HEV-infected animals. Since 2000, there has been increased human hepatitis E incidence reported in Singapore. Although the causes of this increase have not been established, several studies have linked zoonotic HEV infections in humans to pork consumption. It is therefore important to closely monitor the presence of HEV in food sources for the prevalence and virulence. In this study, we demonstrated the presence of HEV in pigs imported into Singapore for consumption through serological and molecular investigation of live pig and post-slaughter samples collected between 2000 and 2019. Among imported pigs, anti-HEV antibody prevalence remained at a level around 35% until 2017, with a statistically significant increase in 2018. HEV RNA was detected in 8.40% (34/405) of the faecal samples, indicative of an active infection in the pigs. HEV RNA was also detected in 6.67% (4/60) of liver samples obtained post-slaughter. We also report the development of an RT-PCR-based next-generation sequencing (NGS) method that enabled full sequencing of the HEV genome in HEV RNA-positive samples in a relatively short span of time. Phylogenetic analysis identified the HEV in one of the imported pigs (HEV-S28) as genotype 3a, which clustered together with the human HEV strains previously identified in Singapore. We found that the HEV-S28 strain exhibited amino acid substitutions that are associated with reduced HEV replication efficiency. The increase in anti-HEV seroprevalence in the pig population from 2018 is worth further exploration. We will continue to monitor the prevalent HEV strains and assess the genetic diversity of HEV in the imported pigs to confirm the potential association with human infections.
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Affiliation(s)
- Yifan Wang
- Center for Animal & Veterinary Sciences, Professional and Scientific Services, Animal and Veterinary Service, National Parks Board (NParks), Singapore, Singapore
| | - Xinyu Toh
- Center for Animal & Veterinary Sciences, Professional and Scientific Services, Animal and Veterinary Service, National Parks Board (NParks), Singapore, Singapore
| | - Jasmine Ong
- Center for Animal & Veterinary Sciences, Professional and Scientific Services, Animal and Veterinary Service, National Parks Board (NParks), Singapore, Singapore
| | - Xuan Hui Teo
- Center for Animal & Veterinary Sciences, Professional and Scientific Services, Animal and Veterinary Service, National Parks Board (NParks), Singapore, Singapore
| | - Patrick Bay
- Singapore Food Agency (SFA), Singapore, Singapore
| | - Charlene Judith Fernandez
- Center for Animal & Veterinary Sciences, Professional and Scientific Services, Animal and Veterinary Service, National Parks Board (NParks), Singapore, Singapore
| | - Taoqi Huangfu
- Center for Animal & Veterinary Sciences, Professional and Scientific Services, Animal and Veterinary Service, National Parks Board (NParks), Singapore, Singapore
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Cullinane A, Gahan J, Walsh C, Nemoto M, Entenfellner J, Olguin-Perglione C, Garvey M, Huang Fu TQ, Venner M, Yamanaka T, Barrandeguy M, Fernandez CJ. Evaluation of Current Equine Influenza Vaccination Protocols Prior to Shipment, Guided by OIE Standards. Vaccines (Basel) 2020; 8:E107. [PMID: 32121419 PMCID: PMC7157717 DOI: 10.3390/vaccines8010107] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/27/2020] [Revised: 02/21/2020] [Accepted: 02/24/2020] [Indexed: 01/28/2023] Open
Abstract
To facilitate the temporary importation of horses for competition and racing purposes, with a minimum risk of transmitting equine influenza, the World Organisation for Animal Health (Office International des Epizooties, or OIE), formally engaged in a public-private partnership with the Federation Equestre Internationale (FEI) and the International Federation for Horseracing Authorities (IFHA) to establish, within the context of existing OIE standards, a science-based rationale to identify the ideal time period for equine influenza vaccination prior to shipment. Field trials using vaccines based on different technologies were carried out on three continents. The antibody response post-booster vaccination at intervals aligned with the different rules/recommendations of the OIE, FEI, and IFHA, was monitored by single radial haemolysis. It was determined that 14 days was the optimum period necessary to allow horses adequate time to respond to booster vaccination and for horses that have previously received four or more doses of vaccine and are older than four years, it is adequate to allow vaccination within 180 days of shipment. In contrast, the results indicate that there is a potential benefit to younger (four years old or younger) horses in requiring booster vaccination within 90 days of shipment, consistent with the current OIE standard.
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Affiliation(s)
- Ann Cullinane
- Virology Unit, The Irish Equine Centre, Naas, Co. Kildare, W91 RH93 Johnstown, Ireland; (J.G.); (M.N.); (M.G.)
| | - Jacinta Gahan
- Virology Unit, The Irish Equine Centre, Naas, Co. Kildare, W91 RH93 Johnstown, Ireland; (J.G.); (M.N.); (M.G.)
| | - Cathal Walsh
- Department of Mathematics and Statistics, University of Limerick, V94 T9PX Limerick, Ireland;
| | - Manabu Nemoto
- Virology Unit, The Irish Equine Centre, Naas, Co. Kildare, W91 RH93 Johnstown, Ireland; (J.G.); (M.N.); (M.G.)
- Equine Research Institute, the Japan Racing Association, 1400-4 Shiba, Shimotsuke, Tochigi 329-0412, Japan;
| | - Johanna Entenfellner
- Equine Clinic, School of Veterinary Medicine, Bischofsholer Damm 15, 30173 Hannover, Germany;
| | - Cecilia Olguin-Perglione
- Instituto Nacional de Tecnología Agropecuaria (INTA), Instituto de Virología, De Los Reseros y Dr. Nicolás Repetto S/N, Hurlingham, Buenos Aires B1686IGC, Argentina;
| | - Marie Garvey
- Virology Unit, The Irish Equine Centre, Naas, Co. Kildare, W91 RH93 Johnstown, Ireland; (J.G.); (M.N.); (M.G.)
| | - Tao Qi Huang Fu
- Centre for Animal and Veterinary Sciences, Professional and Scientific Services, Animal and Veterinary Service, National Parks Board, 1 Cluny Road, Singapore 259569, Singapore; (T.Q.H.F.); (C.J.F.)
| | - Monica Venner
- Pferdeklinik Destedt GmbH, Destedt, Trift 4, 38162 Cremlingen, Germany;
| | - Takashi Yamanaka
- Equine Research Institute, the Japan Racing Association, 1400-4 Shiba, Shimotsuke, Tochigi 329-0412, Japan;
| | - María Barrandeguy
- Escuela de Veterinaria, Universidad del Salvador, Champagnat 1599, Ruta Panamericana km 54.5 Pilar, Buenos Aires B1630AHU, Argentina;
| | - Charlene Judith Fernandez
- Centre for Animal and Veterinary Sciences, Professional and Scientific Services, Animal and Veterinary Service, National Parks Board, 1 Cluny Road, Singapore 259569, Singapore; (T.Q.H.F.); (C.J.F.)
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12
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Xinyu T, Min CS, Yifan W, Lien SM, Chan A, Hui TX, Lee B, Yelin W, Chia-Da H, Oh S, Fernandez CJ, Taoqi H. Canine Parvovirus-2c (CPV-2c) Infection in Wild Asian Palm Civets ( Paradoxurus hermaphroditus) in Singapore. J Wildl Dis 2019; 55:965-969. [PMID: 30920903] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 06/09/2023]
Abstract
We report pathogenic feline parvovirus and canine parvovirus-2c infection in wild Asian palm civets (Paradoxurus hermaphroditus), as demonstrated by histopathology and immunohistochemistry findings of parvoviral enteropathy. We performed molecular characterization and phylogeny studies to obtain an improved understanding of disease transmission dynamics between domestic and wild carnivores.
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Affiliation(s)
- Toh Xinyu
- Animal and Plant Health Center, Virology Section, Animal Health Laboratory Department, Laboratories Group, Agri-Food and Veterinary Authority, 6 Perahu Road, Singapore 718827
| | - Chong Shin Min
- Animal and Plant Health Center, Veterinary Pathology Section, Animal Health Laboratory Department, Laboratories Group, Agri-Food and Veterinary Authority, 6 Perahu Road, Singapore 718827
| | - Wang Yifan
- Animal and Plant Health Center, Virology Section, Animal Health Laboratory Department, Laboratories Group, Agri-Food and Veterinary Authority, 6 Perahu Road, Singapore 718827
| | - Soh Moi Lien
- Animal and Plant Health Center, Virology Section, Animal Health Laboratory Department, Laboratories Group, Agri-Food and Veterinary Authority, 6 Perahu Road, Singapore 718827
| | - Amy Chan
- Animal and Plant Health Center, Veterinary Pathology Section, Animal Health Laboratory Department, Laboratories Group, Agri-Food and Veterinary Authority, 6 Perahu Road, Singapore 718827
| | - Teo Xuan Hui
- Animal and Plant Health Center, Veterinary Pathology Section, Animal Health Laboratory Department, Laboratories Group, Agri-Food and Veterinary Authority, 6 Perahu Road, Singapore 718827
| | - Bernett Lee
- Singapore Immunology Network, Agency for Science, Technology and Research (A*STAR), Immunos Building, 8A Biomedical Grove, Singapore 138648
| | - Wong Yelin
- Animal Section, Surveillance & Inspection Program, Agri-Establishment Regulation Group, Agri-Food and Veterinary Authority, JEM Office Tower, 52 Jurong Gateway Road, #14-01, Singapore 608550
| | - Hsu Chia-Da
- Wildlife Reserves Singapore, 80 Mandai Lake Road, Singapore 729826
| | - Serena Oh
- Wildlife Reserves Singapore, 80 Mandai Lake Road, Singapore 729826
| | - Charlene Judith Fernandez
- Animal and Plant Health Center, Veterinary Pathology Section, Animal Health Laboratory Department, Laboratories Group, Agri-Food and Veterinary Authority, 6 Perahu Road, Singapore 718827
| | - Huangfu Taoqi
- Animal and Plant Health Center, Virology Section, Animal Health Laboratory Department, Laboratories Group, Agri-Food and Veterinary Authority, 6 Perahu Road, Singapore 718827
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13
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Toh X, Soh ML, Ng MK, Yap SC, Harith N, Fernandez CJ, Huangfu T. Isolation and characterization of equine influenza virus (H3N8) from an equine influenza outbreak in Malaysia in 2015. Transbound Emerg Dis 2019; 66:1884-1893. [PMID: 31059176 PMCID: PMC6852086 DOI: 10.1111/tbed.13218] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/30/2019] [Revised: 04/20/2019] [Accepted: 04/29/2019] [Indexed: 12/19/2022]
Abstract
Equine influenza is a major cause of respiratory infections in horses and can spread rapidly despite the availability of commercial vaccines. In this study, we carried out molecular characterization of Equine Influenza Virus (EIV) isolated from the Malaysian outbreak in 2015 by sequencing of the HA and NA gene segments using Sanger sequencing. The nucleotide and amino acid sequences of HA and NA were compared with representative Florida clade 1 and clade 2 strains using phylogenetic analysis. The Florida clade 1 viruses identified in this outbreak revealed numerous amino acid substitutions in the HA protein as compared to the current OIE vaccine strain recommendations and representative strains of circulating Florida sub-lineage clade 1 and clade 2. Differences in HA included amino acids located within antigenic sites which could lead to reduced immune recognition of the outbreak strain and alter the effectiveness of vaccination against the outbreak strain. Detailed surveillance and genetic information sharing could allow genetic drift of equine influenza viruses to be monitored more effectively on a global basis and aid in refinement of vaccine strain selection for EIV.
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Affiliation(s)
- Xinyu Toh
- Centre for Animal and Veterinary Sciences, Professional and Scientific Services, Animal and Veterinary Service, National Parks Board, Singapore City, Singapore
| | - Moi Lien Soh
- Centre for Animal and Veterinary Sciences, Professional and Scientific Services, Animal and Veterinary Service, National Parks Board, Singapore City, Singapore
| | - Mee Keun Ng
- Centre for Animal and Veterinary Sciences, Professional and Scientific Services, Animal and Veterinary Service, National Parks Board, Singapore City, Singapore
| | - Shew Choo Yap
- Centre for Animal and Veterinary Sciences, Professional and Scientific Services, Animal and Veterinary Service, National Parks Board, Singapore City, Singapore
| | - Nurshilla Harith
- Centre for Animal and Veterinary Sciences, Professional and Scientific Services, Animal and Veterinary Service, National Parks Board, Singapore City, Singapore
| | - Charlene Judith Fernandez
- Centre for Animal and Veterinary Sciences, Professional and Scientific Services, Animal and Veterinary Service, National Parks Board, Singapore City, Singapore
| | - Taoqi Huangfu
- Centre for Animal and Veterinary Sciences, Professional and Scientific Services, Animal and Veterinary Service, National Parks Board, Singapore City, Singapore
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14
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Yeo G, Wang Y, Chong SM, Humaidi M, Lim XF, Mailepessov D, Chan S, How CB, Lin YN, Huangfu T, Fernandez CJ, Hapuarachchi HC, Yap G. Characterization of Fowlpox virus in chickens and bird-biting mosquitoes: a molecular approach to investigating Avipoxvirus transmission. J Gen Virol 2019; 100:838-850. [PMID: 30907721 DOI: 10.1099/jgv.0.001209] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022] Open
Abstract
Avian pox is a highly contagious avian disease, yet relatively little is known about the epidemiology and transmission of Avipoxviruses. Using a molecular approach, we report evidence for a potential link between birds and field-caught mosquitoes in the transmission of Fowlpox virus (FWPV) in Singapore. Comparison of fpv167 (P4b), fpv126 (VLTF-1), fpv175-176 (A11R-A12L) and fpv140 (H3L) gene sequences revealed close relatedness between FWPV strains obtained from cutaneous lesions of a chicken and four pools of Culex pseudovishnui, Culex spp. (vishnui group) and Coquellitidea crassipes caught in the vicinity of the study site. Chicken-derived viruses characterized during two separate infections two years later were also identical to those detected in the first event, suggesting repeated transmission of closely related FWPV strains in the locality. Since the study location is home to resident and migratory birds, we postulated that wild birds could be the source of FWPV and that bird-biting mosquitoes could act as bridging mechanical vectors. Therefore, we determined whether the FWPV-positive mosquito pools (n=4) were positive for avian DNA using a polymerase chain reaction-sequencing assay. Our findings confirmed the presence of avian host DNA in all mosquito pools, suggesting a role for Cx. pseudovishnui, Culex spp. (vishnui group) and Cq. crassipes mosquitoes in FWPV transmission. Our study exemplifies the utilization of molecular tools to understand transmission networks of pathogens affecting avian populations, which has important implications for the design of effective control measures to minimize disease burden and economic loss.
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Affiliation(s)
- Gladys Yeo
- 1Environmental Health Institute, National Environment Agency, 11, Biopolis Way, #06-05-08, Singapore 138667, Singapore
| | - Yifan Wang
- 2Agri-Food and Veterinary Authority of Singapore, Animal and Plant Health Centre, 6, Perahu Road, Singapore 718827, Singapore
| | - Shin Min Chong
- 2Agri-Food and Veterinary Authority of Singapore, Animal and Plant Health Centre, 6, Perahu Road, Singapore 718827, Singapore
| | - Mahathir Humaidi
- 1Environmental Health Institute, National Environment Agency, 11, Biopolis Way, #06-05-08, Singapore 138667, Singapore
| | - Xiao Fang Lim
- 1Environmental Health Institute, National Environment Agency, 11, Biopolis Way, #06-05-08, Singapore 138667, Singapore.,†Present address: Duke-NUS Medical School, 8, College Road, Singapore 169857, Singapore
| | - Diyar Mailepessov
- 1Environmental Health Institute, National Environment Agency, 11, Biopolis Way, #06-05-08, Singapore 138667, Singapore
| | - Sharon Chan
- 3Sungei Buloh Wetlands Reserve, National Parks Board, 301, Neo Tiew Cresent, 301, Neo Tiew Cresent, Singapore 718925, Singapore.,‡Present address: Conservation Division, Central Nature Reserve, National Parks Board, 6, Island Club Road, Singapore 578775, Singapore
| | - Choon Beng How
- 3Sungei Buloh Wetlands Reserve, National Parks Board, 301, Neo Tiew Cresent, 301, Neo Tiew Cresent, Singapore 718925, Singapore
| | - Yueh Nuo Lin
- 2Agri-Food and Veterinary Authority of Singapore, Animal and Plant Health Centre, 6, Perahu Road, Singapore 718827, Singapore
| | - Taoqi Huangfu
- 2Agri-Food and Veterinary Authority of Singapore, Animal and Plant Health Centre, 6, Perahu Road, Singapore 718827, Singapore
| | - Charlene Judith Fernandez
- 2Agri-Food and Veterinary Authority of Singapore, Animal and Plant Health Centre, 6, Perahu Road, Singapore 718827, Singapore
| | | | - Grace Yap
- 1Environmental Health Institute, National Environment Agency, 11, Biopolis Way, #06-05-08, Singapore 138667, Singapore.,§Present address: Control of Operations Branch 2, National Environment Agency, 40, Scotts Road, Singapore 228231, Singapore
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15
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Sim SH, Ong CEL, Gan YH, Wang D, Koh VWH, Tan YK, Wong MSY, Chew JSW, Ling SF, Tan BZY, Ye AZ, Bay PCK, Wong WK, Fernandez CJ, Xie S, Jayarajah P, Tahar T, Oh PY, Luz S, Chien JMF, Tan TT, Chai LYA, Fisher D, Liu Y, Loh JJP, Tan GGY. Melioidosis in Singapore: Clinical, Veterinary, and Environmental Perspectives. Trop Med Infect Dis 2018; 3:tropicalmed3010031. [PMID: 30274428 PMCID: PMC6136607 DOI: 10.3390/tropicalmed3010031] [Citation(s) in RCA: 13] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/07/2018] [Revised: 02/23/2018] [Accepted: 03/07/2018] [Indexed: 12/11/2022] Open
Abstract
Melioidosis is a notifiable infectious disease registered with the Ministry of Health (MOH) and Agri-Food & Veterinary Authority (AVA), Singapore. From a clinical perspective, increased awareness of the disease has led to early detection and treatment initiation, thus resulting in decreasing mortality rates in recent years. However, the disease still poses a threat to local pet, zoo and farm animals, where early diagnosis is a challenge. The lack of routine environmental surveillance studies also makes prevention of the disease in animals difficult. To date, there have been no reports that provide a complete picture of how the disease impacts the local human and animal populations in Singapore. Information on the distribution of Burkholderia pseudomallei in the environment is also lacking. The aim of this review is to provide a comprehensive overview of both published and unpublished clinical, veterinary and environmental studies on melioidosis in Singapore to achieve better awareness and management of the disease.
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Affiliation(s)
- Siew Hoon Sim
- Defence Medical and Environmental Research Institute, DSO National Laboratories, Singapore 117510, Singapore.
| | - Catherine Ee Ling Ong
- Defence Medical and Environmental Research Institute, DSO National Laboratories, Singapore 117510, Singapore.
| | - Yunn Hwen Gan
- Department of Biochemistry, Yong Loo Lin School of Medicine, National University of Singapore, Singapore 117597, Singapore.
| | - Dongling Wang
- Defence Medical and Environmental Research Institute, DSO National Laboratories, Singapore 117510, Singapore.
| | - Victor Wee Hong Koh
- Defence Medical and Environmental Research Institute, DSO National Laboratories, Singapore 117510, Singapore.
| | - Yian Kim Tan
- Defence Medical and Environmental Research Institute, DSO National Laboratories, Singapore 117510, Singapore.
| | - Michelle Su Yen Wong
- Defence Medical and Environmental Research Institute, DSO National Laboratories, Singapore 117510, Singapore.
| | - Janet Seok Wei Chew
- Defence Medical and Environmental Research Institute, DSO National Laboratories, Singapore 117510, Singapore.
| | - Sian Foong Ling
- Defence Medical and Environmental Research Institute, DSO National Laboratories, Singapore 117510, Singapore.
| | - Brian Zi Yan Tan
- Laboratories Group, Agri-Food & Veterinary Authority of Singapore, Singapore 718827, Singapore.
| | - Agnes Zhengyu Ye
- Laboratories Group, Agri-Food & Veterinary Authority of Singapore, Singapore 718827, Singapore.
| | - Patrick Chuan Kiat Bay
- Food Establishment Regulation Group, Agri-Food & Veterinary Authority of Singapore, Singapore 608550, Singapore.
| | - Wai Kwan Wong
- Laboratories Group, Agri-Food & Veterinary Authority of Singapore, Singapore 718827, Singapore.
| | | | - Shangzhe Xie
- Conservation, Research and Veterinary Services, Wildlife Reserves Singapore, Singapore 729826, Singapore.
| | - Praveena Jayarajah
- Conservation, Research and Veterinary Services, Wildlife Reserves Singapore, Singapore 729826, Singapore.
| | - Tasha Tahar
- Conservation, Research and Veterinary Services, Wildlife Reserves Singapore, Singapore 729826, Singapore.
| | - Pei Yee Oh
- Conservation, Research and Veterinary Services, Wildlife Reserves Singapore, Singapore 729826, Singapore.
| | - Sonja Luz
- Conservation, Research and Veterinary Services, Wildlife Reserves Singapore, Singapore 729826, Singapore.
| | - Jaime Mei Fong Chien
- Department of Infectious Diseases, Singapore General Hospital, Singapore 169608, Singapore.
| | - Thuan Tong Tan
- Department of Infectious Diseases, Singapore General Hospital, Singapore 169608, Singapore.
| | - Louis Yi Ann Chai
- Division of Infectious Diseases, Department of Medicine, National University Health System, Singapore 119228, Singapore.
- Department of Medicine, Yong Loo Lin School of Medicine, National University of Singapore, Singapore 117597, Singapore.
- National University Cancer Institute, Singapore 119074, Singapore.
| | - Dale Fisher
- Division of Infectious Diseases, Department of Medicine, National University Health System, Singapore 119228, Singapore.
- Department of Medicine, Yong Loo Lin School of Medicine, National University of Singapore, Singapore 117597, Singapore.
| | - Yichun Liu
- Defence Medical and Environmental Research Institute, DSO National Laboratories, Singapore 117510, Singapore.
| | - Jimmy Jin Phang Loh
- Defence Medical and Environmental Research Institute, DSO National Laboratories, Singapore 117510, Singapore.
| | - Gladys Gek Yen Tan
- Defence Medical and Environmental Research Institute, DSO National Laboratories, Singapore 117510, Singapore.
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16
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Chong SM, Wong WK, Lee WY, Tan ZB, Tay YH, Teo XH, Chee LD, Fernandez CJ. Streptococcus agalactiae outbreaks in cultured golden pomfret, Trachinotus blochii (Lacépède), in Singapore. J Fish Dis 2017; 40:971-974. [PMID: 28000924 DOI: 10.1111/jfd.12570] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/13/2016] [Revised: 09/19/2016] [Accepted: 09/20/2016] [Indexed: 06/06/2023]
Affiliation(s)
- S M Chong
- Aquatic Animal Health Laboratory, Animal Health Laboratory, Laboratories Group, Animal & Plant Health Centre, The Agri-Food & Veterinary Authority of Singapore (AVA), Singapore City, Singapore
| | - W K Wong
- Bacteriology Laboratory, Animal Health Laboratory, Laboratories Group, Animal & Plant Health Centre, The Agri-Food & Veterinary Authority of Singapore (AVA), Singapore City, Singapore
| | - W Y Lee
- Bacteriology Laboratory, Animal Health Laboratory, Laboratories Group, Animal & Plant Health Centre, The Agri-Food & Veterinary Authority of Singapore (AVA), Singapore City, Singapore
| | - Z B Tan
- Bacteriology Laboratory, Animal Health Laboratory, Laboratories Group, Animal & Plant Health Centre, The Agri-Food & Veterinary Authority of Singapore (AVA), Singapore City, Singapore
| | - Y H Tay
- Bacteriology Laboratory, Animal Health Laboratory, Laboratories Group, Animal & Plant Health Centre, The Agri-Food & Veterinary Authority of Singapore (AVA), Singapore City, Singapore
| | - X H Teo
- Aquatic Animal Health Laboratory, Animal Health Laboratory, Laboratories Group, Animal & Plant Health Centre, The Agri-Food & Veterinary Authority of Singapore (AVA), Singapore City, Singapore
| | - L D Chee
- Aquatic Animal Health Laboratory, Animal Health Laboratory, Laboratories Group, Animal & Plant Health Centre, The Agri-Food & Veterinary Authority of Singapore (AVA), Singapore City, Singapore
| | - C J Fernandez
- Aquatic Animal Health Laboratory, Animal Health Laboratory, Laboratories Group, Animal & Plant Health Centre, The Agri-Food & Veterinary Authority of Singapore (AVA), Singapore City, Singapore
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17
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Yamanaka T, Nemoto M, Bannai H, Tsujimura K, Kondo T, Matsumura T, Fu TQH, Fernandez CJ, Gildea S, Cullinane A. Rapid diagnosis of equine influenza by highly sensitive silver amplification immunochromatography system. J Vet Med Sci 2017; 79:1061-1063. [PMID: 28458275 PMCID: PMC5487783 DOI: 10.1292/jvms.17-0105] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022] Open
Abstract
Equine influenza (EI) is a respiratory disease caused by equine influenza A virus (EIV,
H3N8) infection. Rapid diagnosis is essential to limit the disease spread. We previously
reported that some rapid antigen detection (RAD) tests are fit for diagnosing EI although
their sensitivity is not optimal. Here, we evaluated the performance of the newly
developed RAD test using silver amplification immunochromatography (Quick Chaser Auto Flu
A, B: QCA) to diagnose EI. The detection limits of QCA for EIVs were five-fold lower than
the conventional RAD tests. The duration of virus antigen detection in the infected horses
was longer than the conventional RAD tests. We conclude that QCA could be a valuable
diagnostic method for EI.
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Affiliation(s)
- Takashi Yamanaka
- Equine Research Institute, the Japan Racing Association, 1400-4 Shiba, Shimotsuke, Tochigi 329-0412, Japan
| | - Manabu Nemoto
- Equine Research Institute, the Japan Racing Association, 1400-4 Shiba, Shimotsuke, Tochigi 329-0412, Japan
| | - Hiroshi Bannai
- Equine Research Institute, the Japan Racing Association, 1400-4 Shiba, Shimotsuke, Tochigi 329-0412, Japan
| | - Koji Tsujimura
- Equine Research Institute, the Japan Racing Association, 1400-4 Shiba, Shimotsuke, Tochigi 329-0412, Japan
| | - Takashi Kondo
- Equine Research Institute, the Japan Racing Association, 1400-4 Shiba, Shimotsuke, Tochigi 329-0412, Japan
| | - Tomio Matsumura
- Equine Research Institute, the Japan Racing Association, 1400-4 Shiba, Shimotsuke, Tochigi 329-0412, Japan
| | - Tao Qi Huang Fu
- Agri-Food & Veterinary Authority of Singapore, Animal and Plant Health Centre, 6 Perahu Road, 718827 Singapore
| | - Charlene Judith Fernandez
- Agri-Food & Veterinary Authority of Singapore, Animal and Plant Health Centre, 6 Perahu Road, 718827 Singapore
| | - Sarah Gildea
- Irish Equine Centre, Johnstown, Naas, Co. Kildare, W91 RH93 Ireland
| | - Ann Cullinane
- Irish Equine Centre, Johnstown, Naas, Co. Kildare, W91 RH93 Ireland
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18
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Fernandez CJ, Haugwitz M, Eaton B, Moore HP. Distinct molecular events during secretory granule biogenesis revealed by sensitivities to brefeldin A. Mol Biol Cell 1997; 8:2171-85. [PMID: 9362061 PMCID: PMC25700 DOI: 10.1091/mbc.8.11.2171] [Citation(s) in RCA: 54] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/05/2023] Open
Abstract
The biogenesis of peptide hormone secretory granules involves a series of sorting, modification, and trafficking steps that initiate in the trans-Golgi and trans-Golgi network (TGN). To investigate their temporal order and interrelationships, we have developed a pulse-chase protocol that follows the synthesis and packaging of a sulfated hormone, pro-opiomelanocortin (POMC). In AtT-20 cells, sulfate is incorporated into POMC predominantly on N-linked endoglycosidase H-resistant oligosaccharides. Subcellular fractionation and pharmacological studies confirm that this sulfation occurs at the trans-Golgi/TGN. Subsequent to sulfation, POMC undergoes a number of molecular events before final storage in dense-core granules. The first step involves the transfer of POMC from the sulfation compartment to a processing compartment (immature secretory granules, ISGs): Inhibiting export of pulse-labeled POMC by brefeldin A (BFA) or a 20 degrees C block prevents its proteolytic conversion to mature adrenocorticotropic hormone. Proteolytic cleavage products were found in vesicular fractions corresponding to ISGs, suggesting that the processing machinery is not appreciably activated until POMC exits the sulfation compartment. A large portion of the labeled hormone is secreted from ISGs as incompletely processed intermediates. This unregulated secretory process occurs only during a limited time window: Granules that have matured for 2 to 3 h exhibit very little unregulated release, as evidenced by the efficient storage of the 15-kDa N-terminal fragment that is generated by a relatively late cleavage event within the maturing granule. The second step of granule biogenesis thus involves two maturation events: proteolytic activation of POMC in ISGs and a transition of the organelle from a state of high unregulated release to one that favors intracellular storage. By using BFA, we show that the two processes occurring in ISGs may be uncoupled: although the unregulated secretion from ISGs is impaired by BFA, proteolytic processing of POMC within this organelle proceeds unaffected. The finding that BFA impairs constitutive secretion from both the TGN and ISGs also suggests that these secretory processes may be related in mechanism. Finally, our data indicate that the unusually high levels of unregulated secretion often associated with endocrine tumors may result, at least in part, from inefficient storage of secretory products at the level of ISGs.
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Affiliation(s)
- C J Fernandez
- Department of Molecular and Cell Biology, University of California, Berkeley 94720-3200, USA
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19
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Fernandez CJ. [Dental management of hemophilia]. Odontoestomatologia 1990; 3:27-40. [PMID: 2152094] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/30/2022] Open
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20
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Abstract
Lateral and transversal distribution of cholesterol ester hydrolase activity in rat liver microsomal membranes has been studied. Total cholesterol ester hydrolase activity was found predominantly (75%) in rough microsomes though specific esterase activities were similar in rough and smooth microsomal fractions. The transversal asymmetry of the enzyme was examined using the criteria of protease sensitivity and latency of mannose-6-phosphate phosphatase. Cholesterol ester hydrolase resulted drastically inhibited by proteolysis with trypsin when microsomal integrity had been previously disrupted with sodium deoxycholate or sodium taurocholate. Under these conditions, most lumenal mannose-6-phosphate phosphatase activity was destroyed. However, cholesterol esterase was unaffected by preincubating microsomes with the detergent alone, which led to the complete expression of latent mannose-6-phosphate phosphatase or by preincubating them with trypsin, where less than a 15% of the lumenal mannose-6-phosphate phosphatase was lost. These findings suggest that cholesterol ester hydrolase activity is located on the lumenal surface of the hepatic microsomal vesicles.
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21
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Abstract
Some kinetic properties of the microsomal cholesterol ester hydrolase (CEH) have been examined in rat liver. The reaction was linear with time up to 60 min and with enzyme concentration up to 0.3 mg/mL, and a pH optimum of 6.7 for enzyme activity was observed. Cholesterol esterase exhibited the following apparent kinetic constants: Km, 68.88 microM and Vmax, 33 Units/mg protein. Cholesteryl palmitate was hydrolyzed to a much greater extent than cholesteryl oleate by the enzyme. Product inhibition with cholesterol and palmitic acid was not apparent; however, oleic acid added to the system reduced markedly microsomal CEH activity. The present paper also reports the solubilization of cholesteryl palmitate hydrolase from the microsomal fraction by pretreating it with Triton X-100, sodium deoxycholate, and sodium dodecylsulfate. All ionic and non-ionic detergents tested are capable of making the enzyme soluble, and maximal effects were found at higher concentrations of detergents although the esterase activity was strongly inhibited. Triton X-100 was found to be more effective than sodium deoxycholate and sodium dodecylsulfate in enzyme and protein solubilization. When the direct effects of detergents on CEH activity were studied, progressive concentration-dependent inhibitions were observed.
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Affiliation(s)
- J M Gandarias
- Department of Physiology and Biochemistry, University of the Basque Country Medical School, Bilbao, Spain
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