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3 results on '"Kewalin Klangthong"'

1. The Distribution and Diversity of Bartonella Species in Rodents and Their Ectoparasites across Thailand.

Author

Kewalin Klangthong, Sommai Promsthaporn, Surachai Leepitakrat, Anthony L Schuster, Patrick W McCardle, Michael Kosoy, and Ratree Takhampunya

Subjects
Medicine, Science
Abstract

Our study highlights the surveillance of Bartonella species among rodents and their associated ectoparasites (ticks, fleas, lice, and mites) in several regions across Thailand. A total of 619 rodents and 554 pooled ectoparasites (287 mite pools, 62 flea pools, 35 louse pools, and 170 tick pools) were collected from 8 provinces within 4 regions of Thailand. Bandicota indica (279), Rattus rattus (163), and R. exulans (96) were the most prevalent species of rats collected in this study. Real-time PCR assay targeting Bartonella-specific ssrA gene was used for screening and each positive sample was confirmed by PCR using nuoG gene. The prevalence of Bartonella DNA in rodent (around 17%) was recorded in all regions. The highest prevalence of Bartonella species was found in B. savilei and R. rattus with the rate of 35.7% (5/14) and 32.5% (53/163), respectively. High prevalence of Bartonella-positive rodent was also found in B. indica (15.1%, 42/279), and R. norvegicus (12.5%, 5/40). In contrast, the prevalence of Bartonella species in ectoparasites collected from the rats varied significantly according to types of ectoparasites. A high prevalence of Bartonella DNA was found in louse pools (Polyplax spp. and Hoplopleura spp., 57.1%) and flea pools (Xenopsylla cheopis, 25.8%), while a low prevalence was found in pools of mites (Leptotrombidium spp. and Ascoschoengastia spp., 1.7%) and ticks (Haemaphysalis spp., 3.5%). Prevalence of Bartonella DNA in ectoparasites collected from Bartonella-positive rodents (19.4%) was significantly higher comparing to ectoparasites from Bartonella-negative rodents (8.7%). The phylogenetic analysis of 41 gltA sequences of 16 Bartonella isolates from rodent blood and 25 Bartonella-positive ectoparasites revealed a wide range of diversity among Bartonella species with a majority of sequences (61.0%) belonging to Bartonella elizabethae complex (11 rodents, 1 mite pool, and 5 louse pools), while the remaining sequences were identical to B. phoceensis (17.1%, 1 mite pool, 5 louse pools, and 1 tick pool), B. coopersplainensis (19.5%, 5 rodents, 1 louse pool, and 2 tick pools), and one previously unidentified Bartonella species (2.4%, 1 louse pool).

Published
2015
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2. Bartonella species and trombiculid mites of rats from the Mekong Delta of Vietnam

Author

Vo Be Hien, Juliet E. Bryant, James Campbell, Kewalin Klangthong, Nguyen Van Cuong, Lynn M. Osikowicz, Juan Carrique-Mas, Sommai Promstaporn, Nguyen Van Minh Hoang, Michael Kosoy, Yannick Chaval, Hoang Kim Loan, Ratree Takhampunya, Serge Morand, Bach Tuan Kiet, Institut Pasteur d'Ho Chi Minh Ville, Réseau International des Instituts Pasteur (RIIP), Oxford University Clinical Research Unit [Hanoi] (OUCRU), Armed Forces Research Institute of Medical Sciences [Bangkok] (AFRIMS), Centers for Disease Control and Prevention (CDC), Subdepartment of Animal Health, Centre de Biologie pour la Gestion des Populations (UMR CBGP), Centre de Coopération Internationale en Recherche Agronomique pour le Développement (Cirad)-Institut National de la Recherche Agronomique (INRA)-Centre international d'études supérieures en sciences agronomiques (Montpellier SupAgro)-Université de Montpellier (UM)-Institut de Recherche pour le Développement (IRD [France-Sud])-Institut national d’études supérieures agronomiques de Montpellier (Montpellier SupAgro), Institut national d'enseignement supérieur pour l'agriculture, l'alimentation et l'environnement (Institut Agro)-Institut national d'enseignement supérieur pour l'agriculture, l'alimentation et l'environnement (Institut Agro), and Work was partly funded by the Vietnam Initiative on Zoonotic Infections (VIZIONS) (grant no. WT/093724), part of the Wellcome Trust Major Overseas Programme (United Kingdom), and the Li-Ka-Shing Foundation (083GR).

Subjects
Veterinary medicine, Disease reservoir, Transovarial transmission, [SDV]Life Sciences [q-bio], Larve, Trombiculidae, Disease Vectors, L73 - Maladies des animaux, law.invention, Rodent Diseases, 0302 clinical medicine, law, Zoonoses, Human Activities, Polymerase chain reaction, 2. Zero hunger, 0303 health sciences, Larva, Parasitologie, biology, Infectious Diseases, Vietnam, Chiggers, Bartonella, Bartonella Infection, L72 - Organismes nuisibles des animaux, Meat, Ectoparasite, 030231 tropical medicine, Real-Time Polymerase Chain Reaction, Microbiology, 03 medical and health sciences, Virology, Bartonella Infections, Animals, Humans, Transmission des maladies, Disease Reservoirs, 030306 microbiology, Rattus, Original Articles, Morbidité, biology.organism_classification, Rats
Abstract

International audience; A survey of Bartonella spp. from 275 rats purchased in food markets (n=150) and trapped in different ecosystems (rice field, forest, and animal farms) (n=125) was carried out during October, 2012-March, 2013, in the Mekong Delta of Vietnam. The overall Bartonella spp. prevalence detected by culture and PCR in blood was 14.9% (10.7-19.1%), the highest corresponding to Rattus tanezumi (49.2%), followed by Rattus norvegicus (20.7%). Trapped rats were also investigated for the presence and type of chiggers (larvae of trombiculid mites), and Bartonella spp. were investigated on chigger pools collected from each rat by RT-PCR. A total of five Bartonella spp. were identified in rats, three of which (B. elizabethae, B. rattimassiliensis, and B. tribocorum) are known zoonotic pathogens. Among trapped rats, factors independently associated with increased prevalence of Bartonella spp. included: (1) Rat species (R. tanezumi); (2) the number of Trombiculini-Blankaartia and Schoengastiini-Ascoschoengastia mites found on rats; and (3) the habitat of the rat (i.e., forest/fields vs. animal farms). The prevalence of Bartonella infection among chiggers from Bartonella spp.-positive R. tanezumi rats was 5/25 (25%), compared with 1/27 (3.7%) among Bartonella spp.-negative R. tanezumi rats (relative risk [RR]=5.4, 95% confidence interval [CI] 0.68-43.09). The finding of Bartonella spp.-positive chiggers on Bartonella spp.-negative rats is strongly suggestive of a transovarial transmission cycle. Rats are ubiquitous in areas of human activity and farms in the Mekong Delta; in addition, trapping and trading of rats for food is common. To correctly assess the human risks due to rat trapping, marketing, and carcass dressing, further studies are needed to establish the routes of transmission and cycle of infection. The widespread presence of these zoonotic pathogens in rats and the abundance of human-rat interactions suggest that surveillance efforts should be enhanced to detect any human cases of Bartonella infection that may arise.

Published
2015
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3. Acceleration of gene transfection efficiency in neuroblastoma cells through polyethyleneimine/poly(methyl methacrylate) core-shell magnetic nanoparticles

Author

Noppawan Woramongkolchai, Saowaluk Chaleawlert-umpon, Kewalin Klangthong, Nattika Saengkrit, Tewin Tencomnao, Somsak Saesoo, and Nuttaporn Pimpha

Subjects
Materials science, LAN-5, Cell Survival, magnetic nanoparticle, Biophysics, Pharmaceutical Science, Nanoparticle, Electrophoretic Mobility Shift Assay, Bioengineering, macromolecular substances, Tryptophan Hydroxylase, Gene delivery, Transfection, non-viral vector, neuronal cells, Biomaterials, Neuroblastoma cell, Neuroblastoma, chemistry.chemical_compound, International Journal of Nanomedicine, Cell Line, Tumor, Drug Discovery, Humans, Polymethyl Methacrylate, Organic chemistry, Particle Size, gene delivery, Methyl methacrylate, Magnetite Nanoparticles, Original Research, Medulla Oblongata, Reverse Transcriptase Polymerase Chain Reaction, tryptophan hydroxylase-2, Organic Chemistry, technology, industry, and agriculture, Tryptophan, General Medicine, equipment and supplies, Poly(methyl methacrylate), chemistry, visual_art, visual_art.visual_art_medium, Magnetic nanoparticles, Imines, Polyethylenes, human activities
Abstract

Tewin Tencomnao,1,* Kewalin Klangthong,2,* Nuttaporn Pimpha,3 Saowaluk Chaleawlert-umpon,3 Somsak Saesoo,3 Noppawan Woramongkolchai,3 Nattika Saengkrit,31Center for Excellence in Omics-Nano Medical Technology Development Project, 2Graduate Program in Clinical Biochemistry and Molecular Medicine, Department of Clinical Chemistry, Faculty of Allied Health Sciences, Chulalongkorn University, Bangkok, 3National Nanotechnology Center, National Science and Technology Development Agency, Pathumthani, Thailand*Both authors contributed equally to this workBackground: The purpose of this study was to demonstrate the potential of magnetic poly(methyl methacrylate) (PMMA) core/polyethyleneimine (PEI) shell (mag-PEI) nanoparticles, which possess high saturation magnetization for gene delivery. By using mag-PEI nanoparticles as a gene carrier, this study focused on evaluation of transfection efficiency under magnetic induction. The potential role of this newly synthesized nanosphere for therapeutic delivery of the tryptophan hydroxylase-2 (TPH-2) gene was also investigated in cultured neuronal LAN-5 cells.Methods: The mag-PEI nanoparticles were prepared by one-step emulsifier-free emulsion polymerization, generating highly loaded and monodispersed magnetic polymeric nanoparticles bearing an amine group. The physicochemical properties of the mag-PEI nanoparticles and DNA-bound mag-PEI nanoparticles were investigated using the gel retardation assay, atomic force microscopy, and zeta size measurements. The gene transfection efficiencies of mag-PEI nanoparticles were evaluated at different transfection times. Confocal laser scanning microscopy confirmed intracellular uptake of the magnetoplex. The optimal conditions for transfection of TPH-2 were selected for therapeutic gene transfection. We isolated the TPH-2 gene from the total RNA of the human medulla oblongata and cloned it into an expression vector. The plasmid containing TPH-2 was subsequently bound onto the surfaces of the mag-PEI nanoparticles via electrostatic interaction. Finally, the mag-PEI nanoparticle magnetoplex was delivered into LAN-5 cells. Reverse-transcriptase polymerase chain reaction was performed to evaluate TPH-2 expression in a quantitative manner.Results: The study demonstrated the role of newly synthesized high-magnetization mag-PEI nanoparticles for gene transfection in vitro. The expression signals of a model gene, luciferase, and a therapeutic gene, TPH-2, were enhanced under magnetic-assisted transfection. An in vitro study in neuronal cells confirmed that using mag-PEI nanoparticles as a DNA carrier for gene delivery provided high transfection efficiency with low cytotoxicity.Conclusion: The mag-PEI nanoparticle is a promising alternative gene transfection reagent due to its ease of use, effectiveness, and low cellular toxicity. The mag-PEI nanoparticle is not only practical for gene transfection in cultured neuronal cells but may also be suitable for transfection in other cells as well.Keywords: magnetic nanoparticle, non-viral vector, gene delivery, tryptophan hydroxylase-2, LAN-5, neuronal cells

Published
2012
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