Publications by authors named "Nutthawan Nonthabenjawan"

16 Publications

  • Page 1 of 1

Identification of GII.14[P7] norovirus and its genomic mutations from a case of long-term infection in a post-symptomatic individual.

Infect Genet Evol 2020 12 1;86:104612. Epub 2020 Nov 1.

Thailand-Japan Research Collaboration Center on Emerging and Re-emerging Infections, Nonthaburi, Thailand. Electronic address:

Norovirus is a leading cause of acute gastroenteritis worldwide. Norovirus shedding typically lasts one week to one month after the onset of diarrhea in immunocompetent hosts. The occurrence of mutations in the genome during infection has contributed to the evolution of norovirus. It has been suggested that genomic mutations in the P2-domain of capsid protein VP1, the major antigenic site for virus clearance, are involved in the evasion of host immunity and prolonged shedding of norovirus. In our previous study, we found a case of long-term shedding of GII.14 norovirus in a post-symptomatic immunocompetent individual that lasted about three months. In this study, we characterized the genomic sequence of the GII.14 strain to gain insight into the context of long-term shedding. By sequencing a 4.8 kb region of the genome corresponding to half of ORF1 and the entire ORF2 and ORF3, which encode several non-structural proteins and the structural proteins VP1 and VP2, the GII.14 strain was found to be classified as recombinant GII.14[P7]. Six point-mutations occurred during the three-month period of infection in a time-dependent manner in the genomic regions encoding RNA-dependent RNA polymerase, VP1, and VP2. Three of the six mutations were sense mutations, but no amino acid substitution was identified in the P2-domain of VP1. These results suggest that there is a mechanism by which long-term shedding of norovirus occurs in immunocompetent individuals independent of P2-domain mutations.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.1016/j.meegid.2020.104612DOI Listing
December 2020

Norovirus transmission mediated by asymptomatic family members in households.

PLoS One 2020 23;15(7):e0236502. Epub 2020 Jul 23.

Thailand-Japan Research Collaboration Center on Emerging and Re-emerging Infections, Nonthaburi, Thailand.

The transmission of human norovirus excreted from infected persons occasionally causes sporadic infections and outbreaks. Both symptomatic patients and asymptomatic carriers have been reported to contribute to norovirus transmission, but little is known about the magnitude of the contribution of asymptomatic carriers. We carried out a 1-year survey of residents of a district of Bangkok, Thailand to determine the percentage of norovirus transmissions originating from asymptomatic individuals. We screened 38 individuals recruited from 16 families from May 2018 to April 2019 for GI and GII genotypes. Norovirus was detected every month, and 101 of 716 stool samples (14.1%) from individuals with no symptoms of acute gastroenteritis were norovirus-positive. The average infection frequency was 2.4 times per person per year. Fourteen genotypes were identified from the positive samples, with GII.4 being detected most frequently. Notably, 89.1% of the norovirus-positive samples were provided by individuals with no diarrhea episode. Similar to cases of symptomatic infections in Thailand, asymptomatic infections were observed most frequently in December. We detected 4 cases of NV infection caused by household transmission, and 3 of the 4 transmissions originated from asymptomatic individuals. We also identified a case in which norovirus derived from an asymptomatic individual caused diarrhea in a family member. These results suggest that asymptomatic individuals play a substantial role in both the maintenance and spreading of norovirus in a community through household transmission.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://journals.plos.org/plosone/article?id=10.1371/journal.pone.0236502PLOS
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC7377487PMC
September 2020

Genetic characterization of infectious bronchitis viruses in Thailand, 2014-2016: identification of a novel recombinant variant.

Poult Sci 2020 Apr 5;99(4):1888-1895. Epub 2020 Feb 5.

Department of Veterinary Microbiology, Faculty of Veterinary Science, Chulalongkorn University, Bangkok, Thailand; Emerging and Re-emerging Infectious Diseases in Animals (CUEIDAs), Center of Excellence, Faculty of Veterinary Science, Chulalongkorn University, Bangkok, Thailand. Electronic address:

Infectious bronchitis (IB) causes severe economic losses to the poultry industry worldwide owing to frequent emergence of novel infectious bronchitis virus (IBV) variants, which potentially affect the effectiveness of the currently used IBV vaccine. Therefore, continuous monitoring of IBV genotypes and lineages recently circulating in chickens worldwide is essential. In this study, we characterized the complete S1 gene from 120 IBVs circulating in chickens in Thailand from 2014 to 2016. Phylogenetic analysis of the complete S1 gene of 120 Thai IBVs revealed that the 2014-2016 Thai IBVs were divided into 3 lineages (GI-1, GI-13, and GI-19) and a novel IBV variant. Our results also showed that GI-19 lineage has become the predominant lineage of IBV circulating in chicken flocks in Thailand from 2014 to 2016. It is interesting to note that a novel IBV variant, which was genetically different from the established IBV lineages, was identified in this study. The recombination analysis demonstrated that this novel IBV variant was a recombinant virus, which was originated from the GI-19 and GI-13 lineage viruses. In conclusion, our data demonstrate the circulation of different lineages of IBV and the presence of a novel recombinant IBV variant in chicken flocks in Thailand. This study highlights the high genetic diversity and continued evolution of IBVs in chickens in Thailand, and the importance of continued IBV surveillance for effective control and prevention of IB.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.1016/j.psj.2019.11.044DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC7173020PMC
April 2020

Influenza A(H9N2) Virus, Myanmar, 2014-2015.

Emerg Infect Dis 2017 06;23(6):1041-1043

Routine surveillance of influenza A virus was conducted in Myanmar during 2014-2015. Influenza A(H9N2) virus was isolated in Shan State, upper Myanmar. Whole-genome sequencing showed that H9N2 virus from Myanmar was closely related to H9N2 virus of clade 4.2.5 from China.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.3201/eid2306.161902DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC5443444PMC
June 2017

Outbreaks of Tilapia Lake Virus Infection, Thailand, 2015-2016.

Emerg Infect Dis 2017 06;23(6):1031-1033

During 2015-2016, several outbreaks of tilapia lake virus infection occurred among tilapia in Thailand. Phylogenetic analysis showed that the virus from Thailand grouped with a tilapia virus (family Orthomyxoviridae) from Israel. This emerging virus is a threat to tilapia aquaculture in Asia and worldwide.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.3201/eid2306.161278DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC5443430PMC
June 2017

Time-space analysis of highly pathogenic avian influenza H5N2 outbreak in the US.

Virol J 2016 08 30;13(1):147. Epub 2016 Aug 30.

Department of Veterinary Population Medicine, College of Veterinary Medicine, University of Minnesota, 1971 Commonwealth Avenue, Rm 301E, St. Paul, MN, 55108, USA.

Background: In early 2015, highly pathogenic avian influenza H5N2 caused outbreaks in commercial poultry farms in Minnesota and neighboring states where more than 48 million birds were affected. To date, the origin and transmission pathways of HPAI H5N2 have not been conclusively established.

Methods: In this study, we analyzed forty-six samples from turkeys and their environment that were collected at different time-points of the outbreak to identify origins and within outbreak evolutionary changes. We performed de-novo whole genome sequencing from primary samples and the most recent common ancestors of the PB2, PA, HA5, M and NS segments were traced back to Japanese HPAI H5N8 isolates. These segments appeared to have diverged from the ancestor around June and November 2014.

Results: The time to most recent common ancestor analysis for PB1, NP and NA2 segments suggest two likely possibilities of reassortant HPAI H5N2 origin - either a reassortment in Alaska area or multiple reassortments with North American low pathogenic avian influenza strains, before the HPAI H5N2 outbreak strain emerged. Within the outbreak, viruses clustered into two and three subgroups suggesting high substitution rates of 0.702x10-2 - 1.665x10-2 (subs/site/year), over the 5-month outbreak period.

Conclusions: Data are suggestive of a fast evolving HPAI strain within an outbreak that should be taken into consideration in developing appropriate control strategies in the future.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.1186/s12985-016-0605-4DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC5006563PMC
August 2016

Genetic characterization of influenza A virus subtypes H1N3 and H1N9 isolated from free-grazing ducks in Thailand.

Arch Virol 2016 Oct 6;161(10):2819-24. Epub 2016 Jul 6.

Department of Veterinary Public Health, Faculty of Veterinary Science, Chulalongkorn University, Bangkok, 10330, Thailand.

Influenza A virus (IAV) subtype H1 has been reported to infect birds, pigs and humans. In this study, we characterized IAVs subtype H1N3 and H1N9 isolated from free-grazing ducks in Thailand. Phylogenetic analysis showed that Thai IAV-H1 isolates cluster with avian Eurasian-lineage but not pandemic H1N1 viruses. Analysis of the viruses indicated low-pathogenic avian influenza (LPAI) characteristics. This study is the first report of avian H1N3 and H1N9 in Thailand. Although Thai IAV-H1 viruses do not pose a risk of a pandemic, routine surveillance and genetic monitoring of IAVs should be conducted.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.1007/s00705-016-2962-0DOI Listing
October 2016

Genetic characterization of influenza A (H7N6) virus isolated from a live-bird market in Thailand.

Arch Virol 2016 May 21;161(5):1315-22. Epub 2016 Jan 21.

Department of Veterinary Public Health, Faculty of Veterinary Science, Chulalongkorn University, Bangkok, 10330, Thailand.

A one-year influenza A virus (IAV) monitoring program was conducted in a live-bird market (LBM) in Thailand. Using one-step real-time RT-PCR (rRT-PCR), 2.39 % of live birds were found to be IAV positive. Twenty viruses could be identified as IAV subtype H7N6. Eight IAV-H7N6 viruses were subjected to whole-genome sequencing and genetic characterization. Phylogenetic analysis showed that the HA gene of Thai H7N6 is grouped with those of the H7 Eurasian viruses. The NA gene is closely related to those of the N6 Eurasian viruses. This is the first report of IAV subtype H7N6 in Thailand.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.1007/s00705-016-2759-1DOI Listing
May 2016

Sentinel model for influenza A virus monitoring in free-grazing ducks in Thailand.

Vet Microbiol 2016 29;182:35-43. Epub 2015 Oct 29.

Center of Excellence for Emerging and Re-emerging Infectious Diseases in Animals, Faculty of Veterinary Science, Chulalongkorn University, Bangkok, Thailand; Department of Veterinary Public Health, Faculty of Veterinary Science, Chulalongkorn University, Bangkok, Thailand. Electronic address:

Influenza A virus (IAV) can cause influenza in birds and mammals. In Thailand, free-grazing ducks are known IAV reservoirs and can spread viruses through frequent movements in habitats they share with wild birds. In this study, the sentinel model for IAV monitoring was conducted over 4 months in two free-grazing duck flocks. IAV subtypes H4N6 (n=1) and H3N8 (n=5) were isolated from sentinel ducks at the ages of 13 and 15 weeks. Clinical signs of depression and ocular discharge were observed in the infected ducks. Phylogenetic analysis and genetic characterization of the isolated IAVs indicated that all Thai IAVs were clustered in the Eurasian lineage and pose low pathogenic avian influenza characteristics. Serological analysis found that antibodies against IAVs could be detected in the ducks since 9-weeks-old. In summary, our results indicate that the sentinel model can be used for IAV monitoring in free-grazing duck flocks. Since free-grazing ducks are potential reservoirs and transmitters of IAVs, routine IAV surveillance in free-grazing duck flocks can be beneficial for influenza prevention and control strategies.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.1016/j.vetmic.2015.10.023DOI Listing
September 2016

Tembusu-Related Flavivirus in Ducks, Thailand.

Emerg Infect Dis 2015 Dec;21(12):2164-7

Since 2013, outbreaks of disease caused by duck Tembusu virus (DTMUV) have been observed in layer and broiler duck farms in Thailand. The virus is closely related to Chinese DTMUVs and belongs to the Ntaya group of mosquitoborne flaviviruses. These findings represent the emergence of DTMUV in ducks in Thailand.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.3201/eid2112.150600DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC4672441PMC
December 2015

Genetic diversity of swine influenza viruses in Thai swine farms, 2011-2014.

Virus Genes 2015 Apr 12;50(2):221-30. Epub 2014 Dec 12.

Faculty of Veterinary Science, Center of Excellence for Emerging and Re-emerging Infectious Diseases in Animals, Chulalongkorn University, Bangkok, Thailand,

The pig is known as a "mixing vessel" for influenza A viruses. The co-circulation of multiple influenza A subtypes in pig populations can lead to novel reassortant strains. For this study, swine influenza surveillance was conducted from September 2011 to February 2014 on 46 swine farms in Thailand. In total, 78 swine influenza viruses were isolated from 2,821 nasal swabs, and 12 were selected for characterization by whole genome sequencing. Our results showed that the co-circulation of swine influenza subtypes H1N1, H3N2, and H1N2 in Thai swine farms was observable throughout the 3 years of surveillance. Furthermore, we repeatedly found reassortant viruses between endemic swine influenza viruses and pandemic H1N1 2009. This observation suggests that there is significant and rapid evolution of swine influenza viruses in swine. Thus, continuous surveillance is critical for monitoring novel reassortant influenza A viruses in Thai swine populations.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.1007/s11262-014-1153-xDOI Listing
April 2015

Genetic characterization of influenza A virus subtype H7N1 isolated from quail, Thailand.

Virus Genes 2014 Dec 28;49(3):428-37. Epub 2014 Sep 28.

Center of Excellence for Emerging and Re-emerging Infectious Diseases in Animals, Faculty of Veterinary Science, Chulalongkorn University, Bangkok, 10330, Thailand,

In Thailand, surveillance for the highly pathogenic avian influenza virus H5N1 (HPAI-H5N1) has revealed high prevalence of the virus in quail in live-bird markets. This study monitored avian influenza viruses (AIVs) in quail farms in an area at high risk for HPAI-H5N1 over a 12-month period from 2009 to 2010. One-step real-time RT-PCR (rRT-PCR) results showed that 1.18 % of swab samples (24/2,040) were AIV positive. Among the rRT-PCR positive samples, three samples were identified as subtype H7N1. One Thai H7N1 virus designated "A/quail/Thailand/CU-J2882/2009 (H7N1)" was subjected to whole genome sequencing and genetic characterization. Phylogenetic analysis showed that the HA gene of the Thai H7N1 virus groups with those of the H7 Eurasian viruses. Interestingly, the NA gene of the virus was found to be closely related to those of the HPAI-H5N1 viruses from Vietnam and Thailand. This study constitutes the first report on AIV H7N1 in Thailand. Our results suggest the possibility of genetic reassortment between AIV-H7NX and HPAI-H5N1 in quail. The HA cleavage site of the Thai H7N1 virus contains no multiple amino acid insertions, suggesting low pathogenic characteristics for this virus.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.1007/s11262-014-1120-6DOI Listing
December 2014

Genetic characterization of canine influenza A virus (H3N2) in Thailand.

Virus Genes 2014 Feb 8;48(1):56-63. Epub 2013 Oct 8.

Center of Excellence for Emerging and Re-emerging Infectious Diseases in Animals, Faculty of Veterinary Science, Chulalongkorn University, Bangkok, 10330, Thailand.

In January 2012, several clinical cases of dogs with flu-like symptoms, including coughing, sneezing, nasal discharge, and fever, were reported in a small-animal hospital located in Bangkok, Thailand. One influenza A virus was identified and characterized as an avian-like influenza virus H3N2. The virus was named A/canine/Thailand/CU-DC5299/12. A phylogenetic analysis indicated that the canine virus belonged to an avian Eurasian lineage and was genetically related to the canine influenza viruses H3N2 from China and Korea. This canine virus displays a unique genetic signature with two amino acid insertions in the NA protein, which is similar to the canine influenza viruses from eastern China (Zhejiang and Jiangsu). This study constitutes the first report of H3N2 canine influenza virus infection in a small-animal hospital in Thailand.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.1007/s11262-013-0978-zDOI Listing
February 2014

Genetic characterization of Thai swine influenza viruses after the introduction of pandemic H1N1 2009.

Virus Genes 2013 Aug 6;47(1):75-85. Epub 2013 Jun 6.

Department of Pathology, Faculty of Veterinary Science, Chulalongkorn University, Henri-Dunant Road, Bangkok 10330, Thailand.

Pandemic H1N1 2009 (pH1N1), influenza virus containing triple reassortant internal genes (TRIG) from avian, human, and swine influenza viruses emerged in 2009 as a highly infectious virus that was able to be transmitted from humans to pigs. During June 2010-May 2012, influenza virus surveillance was conducted in Thai pig population. Twenty-three samples (1.75%) were successfully isolated from total of 1,335 samples. Interestingly, pH1N1 (7 isolates, 30.34%), reassortant pH1N1 (rH1N1) (1 isolate, 4.35%), Thai endemic H1N1 (enH1N1) (3 isolates, 13.04%), reassortant H3N2 with pH1N1 internal genes (rH3N2) (9 isolates, 39.13%), and reassortant H1N2 with pH1N1 internal genes (rH1N2) (3 isolates, 13.04%) were found. It should be noted that rH1N1, rH1N2, and rH3N2 viruses contained the internal genes of pH1N1 virus having a TRIG cassette descendant from the North American swine lineage. Although all isolates in this study were obtained from mild clinically sick pigs, the viruses were still highly infective and possibly may play an important role in human-animal interfacing transmission. In addition, the TRIG cassette may have an influence on antigenic shift resulting in emergence of novel viruses, as seen in this study. Continuing surveillance of influenza A natural hosts, particularly in pigs is necessary.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.1007/s11262-013-0927-xDOI Listing
August 2013

Genetic characterization of influenza A virus subtype H12N1 isolated from a watercock and lesser whistling ducks in Thailand.

Arch Virol 2012 Jun 26;157(6):1123-30. Epub 2012 Feb 26.

Emerging and Re-emerging Infectious Diseases in Animals, Research Unit, Faculty of Veterinary Science, Chulalongkorn University, Bangkok, Thailand.

Monitoring of influenza A virus (IAV) was conducted in wild bird species in central Thailand. Four IAV subtype H12N1 strains were isolated from a watercock (order Gruiformes, family Rallidae) (n = 1) and lesser whistling ducks (order Anseriformes, family Anatidae) (n = 3). All H12N1 viruses were characterized by whole-genome sequencing. Phylogenetic analysis of all eight genes of the Thai H12N1 viruses indicated that they are most closely related to the Eurasian strains. Analysis of the HA gene revealed the strains to be of low pathogenicity. This study is the first to report the circulation of IAV subtype H12N1 in Thailand and to describe the genetic characteristics of H12N1 in Eurasia. Moreover, the genetic information obtained on H12N1 has contributed a new Eurasian strain of H12N1 to the GenBank database.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.1007/s00705-012-1260-8DOI Listing
June 2012