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Publication Open Access Comparison of two multilocus sequence based genotyping schemes for Leptospira species.(2011-11) Ahmed, Ahmed; Janjira Thaipadungpanit; จันทร์จิรา ไทยผดุงพานิช; Siriphan Boonsilp; ศิริพรรณ บุญศิลป์; Vanaporn Wuthiekanun; วรรณพร วุฒิเอกอนันต์; Nalam, Kishore; Spratt, Brian G.; Aanensen, David M.; Smythe, Lee D.; Ahmed, Niyaz; Feil, Edward J.; Hartskeer, Rudy A.; Peacock, Sharon J.; Ahmed, Ahmed; Mahidol University. Faculty of Tropical Medicine. Department of Microbiology and Immunology.; Mahidol University. Faculty of Tropical Medicine. Mahidol-Oxford Tropical Medicine Research Unit.; Mahidol Univeristy. Faculty of Medicine Siriraj Hospital. Medical Proteomics Unit, Office for Research and Development.BACKGROUND: Several sequence based genotyping schemes have been developed for Leptospira spp. The objective of this study was to genotype a collection of clinical and reference isolates using the two most commonly used schemes and comparePublication Open Access Genome sequencing defines phylogeny and spread of methicillin-resistant Staphylococcus aureus in a high transmission setting.(2015-01) Tong, Steven Y.C.; Holden, Matthew T.G.; Nickerson, Emma K.; Cooper, Ben S.; Köser, Claudio U.; Cori, Anne; Jombart, Thibaut; Cauchemez, Simon; Fraser, Christophe; Vanaporn Wuthiekanun; วรรณพร วุฒิเอกอนันต์; Janjira Thaipadungpanit; จันทร์จิรา ไทยผดุงพานิช; Maliwan Hongsuwan; มะลิวัลย์ หงษ์สุวรรณ; Day, Nicholas P.; Direk Limmathurotsakul; ดิเรก ลิ้มมธุรสกุล; Parkhill, Julian; Peacock, Sharon J.; Peacock, Sharon J.; Mahidol University. Faculty of Tropical Medicine. Mahidol-Oxford Tropical Medicine Research Unit.colonized by more than one clade. One patient on each unit was the source of numerous transmission events, and deep sampling of one of these cases demonstrated colonization with a "cloud" of related MRSA variants. The application of whole-genome... of nosocomial infection occurs in resource-restricted settings where barriers to transmission are lower. Here, we study the flux and genetic diversity of MRSA on ward and individual patient levels in a hospital where transmission was common. We repeatedlyPublication Open Access Systematic review and consensus guidelines for environmental sampling of Burkholderia pseudomallei(2013-03) Direk Limmathurotsakul; ดิเรก ลิ้มมธุรสกุล; Dance, David A. B.; Vanaporn Wuthiekanun; Kaestli, Mirjam; Mayo, Mark; Warner, Jeffrey; Wagner, David M.; Apichai Tuanyok; Wertheim, Heiman; Cheng, Tan Yoke; Mukhopadhyay, Chiranjay; Puthucheary, Savithiri; Day,Nicholas P. J.; Steinmetz, Ivo; Currie, Bart J.; Peacock, Sharon J.; Direk Limmathurotsakul; Mahidol University. Faculty of Tropical Medicine. Department of Tropical Hygiene; Mahidol University. Faculty of Tropical Medicine. Mahidol-Oxford Tropical Medicine Research Unit; Mahidol University. Faculty of Tropical Medicine. Department of Microbiology and Immunologyand categorized as definite, probable, or possible. The methodology used for detecting environmental B. pseudomallei was extracted and collated. We found that global coverage was patchy, with a lack of studies in many areas where melioidosis is suspected... of affordable and 'low-tech' methodology that is applicable in both developed and developing countries. CONCLUSIONS/SIGNIFICANCE: The proposed consensus guidelines provide the basis for the development of an accurate and comprehensive global mapPublication Open Access A single multilocus sequence typing (MLST) scheme for seven pathogenic Leptospira species(2013) Siriphan Boonsilp; ศิริพรรณ บุญศิลป์; Janjira Thaipadungpanit; จันทรจิรา ไทยผดุงพานิช; Premjit Amornchai; เปรมจิตร อมรชัย; Vanaporn Wuthiekanun; วรรณพร วุฒิเอกอนันต์; Bailey, Mark S.; Holden, Matthew T. G.; Zhang, Cuicai; Jiang, Xiugao; Koizumi, Nobuo; Taylor, Kyle; Galloway, Renee; Hoffmaster, Alex R.; Craig, Scott; Smythe, Lee D.; Hartskeerl, Rudy A.; Day, Nicholas P.; Narisara Chantratita; นริศรา จันทราทิตย์; Feil, Edward J.; Aanensen, David M.; Spratt, Brian G.; Peacock, Sharon J.; Janjira Thaipadungpanit; Mahidol University. Faculty of Tropical Medicine. Mahidol-Oxford Tropical Medicine Research Unit; Mahidol University. Faculty of Tropical Medicine. Department of Microbiology and ImmunologyBACKGROUND: The available Leptospira multilocus sequence typing (MLST) scheme supported by a MLST website is limited to L. interrogans and L. kirschneri. Our aim was to broaden the utility of this scheme to incorporate a total of seven pathogenic species. METHODOLOGY AND FINDINGS: We modified the existing scheme by replacing one of the seven MLST loci (fadD was changed to caiB), as the former gene did not appear to be present in some pathogenic species. Comparison of the original and modified schemes using data for L. interrogans and L. kirschneri demonstrated that the discriminatory power of the two schemes was not significantly different. The modified scheme was used to further characterize 325 isolates (L. alexanderi [n = 5], L. borgpetersenii [n = 34], L. interrogans [n = 222], L. kirschneri [n = 29], L. noguchii [n = 9], L. santarosai [n = 10], and L. weilii [n = 16]). Phylogenetic analysis using concatenated sequences of the 7 loci demonstrated that each species corresponded to a discrete clade, and that no strains were misclassified at the species level. Comparison between genotype and serovar was possible for 254 isolates. Of the 31 sequence types (STs) represented by at least two isolates, 18 STs included isolates assigned to two or three different serovars. Conversely, 14 serovars were identified that contained between 2 to 10 different STs. New observations were made on the global phylogeography of Leptospira spp., and the utility of MLST in making associations between human disease and specific maintenance hosts was demonstrated. CONCLUSION: The new MLST scheme, supported by an updated MLST website, allows the characterization and species assignment of isolates of the seven major pathogenic species associated with leptospirosis.Publication Open Access Genetic diversity and microevolution of Burkholderia pseudomallei in the environment.(2008-02-20) Narisara Chantratita; นริศรา จันทราทิตย์; Vanaporn Wuthiekanun; วรรณพร วุฒิเอกอนันต์; Direk Limmathurotsakul; ดิเรก ลิ้มมธุรสกุล; Mongkol Vesaratchavest; มงคล เวสารัชเวศย์; Aunchalee Thanwisai; อัญชลี ฐานวิสัย; Premjit Amornchai; เปรมจิตร อมรชัย; Sarinna Tumapa; สรินนา ทุมาภา; Feil, Edward J.; Day, Nicholas P.; Peacock, Sharon J.; Peacock, Sharon J.; Mahidol University. Faculty of Tropical Medicine. Mahidol-Oxford Tropical Medicine Research Unit.BACKGROUND: The soil dwelling Gram-negative pathogen Burkholderia pseudomallei is the cause of melioidosis. The diversity and population structure of this organism in the environment is poorly defined. METHODS AND FINDINGS: We undertook a study of BPublication Open Access NLRC4 and TLR5 each contribute to host defense in respiratory melioidosis.(2014-09-18) West, T. Eoin; Myers, Nicolle D.; Narisara Chantratita; นริศรา จันทราทิตย์; Wirongrong Chierakul; วิรงค์รอง เจียรกุล; Direk Limmathurotsakul; ดิเรก ลิ้มมธุรสกุล; Vanaporn Wuthiekanun; วรรณพร วุฒิเอกอนันต์; Miao, Edward A.; Hajjar, Adeline M.; Peacock, Sharon J.; Liggitt, H. Denny; Skerrett, Shawn J.; West, T. Eoin; Mahidol University. Faculty of Tropical Medicine. Mahidol-Oxford Tropical Medicine Research Unit.; Mahidol University. Faculty of Tropical Medicine. Department of Clinical Tropical Medicine.; Mahidol University. Faculty of Tropical Medicine. Department of Microbiology and Immunology.; Mahidol University. Faculty of Tropical Medicine. Department of Tropical Hygiene.Burkholderia pseudomallei causes the tropical infection melioidosis. Pneumonia is a common manifestation of melioidosis and is associated with high mortality. Understanding the key elements of host defense is essential to developing new therapeutics for melioidosis. As a flagellated bacterium encoding type III secretion systems, B. pseudomallei may trigger numerous host pathogen recognition receptors. TLR5 is a flagellin sensor located on the plasma membrane. NLRC4, along with NAIP proteins, assembles a canonical caspase-1-dependent inflammasome in the cytoplasm that responds to flagellin (in mice) and type III secretion system components (in mice and humans). In a murine model of respiratory melioidosis, Tlr5 and Nlrc4 each contributed to survival. Mice deficient in both Tlr5 and Nlrc4 were not more susceptible than single knockout animals. Deficiency of Casp1/Casp11 resulted in impaired bacterial control in the lung and spleen; in the lung much of this effect was attributable to Nlrc4, despite relative preservation of pulmonary IL-1β production in Nlrc4(-/-) mice. Histologically, deficiency of Casp1/Casp11 imparted more severe pulmonary inflammation than deficiency of Nlrc4. The human NLRC4 region polymorphism rs6757121 was associated with survival in melioidosis patients with pulmonary involvement. Co-inheritance of rs6757121 and a functional TLR5 polymorphism had an additive effect on survival. Our results show that NLRC4 and TLR5, key components of two flagellin sensing pathways, each contribute to host defense in respiratory melioidosis.