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Search Results: 1 - 3 of 3 matches for " Piengchan Sonthayanon "
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The Diversity and Geographical Structure of Orientia tsutsugamushi Strains from Scrub Typhus Patients in Laos
Rattanaphone Phetsouvanh?,Piengchan Sonthayanon,Sasithon Pukrittayakamee?,Daniel H. Paris?,Paul N. Newton?,Edward J. Feil?,Nicholas P. J. Day
PLOS Neglected Tropical Diseases , 2015, DOI: 10.1371/journal.pntd.0004024
Abstract: Orientia tsutsugamushi is the causative agent of scrub typhus, a disease transmitted by Leptotrombidium mites which is responsible for a severe and under-reported public health burden throughout Southeast Asia. Here we use multilocus sequence typing (MLST) to characterize 74 clinical isolates from three geographic locations in the Lao PDR (Laos), and compare them with isolates described from Udon Thani, northeast Thailand. The data confirm high levels of diversity and recombination within the natural O. tsutsugamushi population, and a rate of mixed infection of ~8%. We compared the relationships and geographical structuring of the strains and populations using allele based approaches (eBURST), phylogenetic approaches, and by calculating F-statistics (FST). These analyses all point towards low levels of population differentiation between isolates from Vientiane and Udon Thani, cities which straddle the Mekong River which defines the Lao/Thai border, but with a very distinct population in Salavan, southern Laos. These data highlight how land use, as well as the movement of hosts and vectors, may impact on the epidemiology of zoonotic infections.
High Rates of Homologous Recombination in the Mite Endosymbiont and Opportunistic Human Pathogen Orientia tsutsugamushi
Piengchan Sonthayanon ,Sharon J. Peacock,Wirongrong Chierakul,Vanaporn Wuthiekanun,Stuart D. Blacksell,Mathew T. G. Holden,Stephen D. Bentley,Edward J. Feil,Nicholas P. J. Day
PLOS Neglected Tropical Diseases , 2010, DOI: 10.1371/journal.pntd.0000752
Abstract: Orientia tsutsugamushi is an intracellular α-proteobacterium which resides in trombiculid mites, and is the causative agent of scrub typhus in East Asia. The genome sequence of this species has revealed an unprecedented number of repeat sequences, most notably of the genes encoding the conjugative properties of a type IV secretion system (T4SS). Although this observation is consistent with frequent intragenomic recombination, the extent of homologous recombination (gene conversion) in this species is unknown. To address this question, and to provide a protocol for the epidemiological surveillance of this important pathogen, we have developed a multilocus sequence typing (MLST) scheme based on 7 housekeeping genes (gpsA, mdh, nrdB, nuoF, ppdK, sucD, sucB). We applied this scheme to the two published genomes, and to DNA extracted from blood taken from 84 Thai scrub typhus patients, from 20 cultured Thai patient isolates, 1 Australian patient sample, and from 3 cultured type strains. These data demonstrated that the O. tsutsugamushi population was both highly diverse [Simpson's index (95% CI) = 0.95 (0.92–0.98)], and highly recombinogenic. These results are surprising given the intracellular life-style of this species, but are broadly consistent with results obtained for Wolbachia, which is an α-proteobacterial reproductive parasite of arthropods. We also compared the MLST data with ompA sequence data and noted low levels of consistency and much higher discrimination by MLST. Finally, twenty-five percent of patients in this study were simultaneously infected with multiple sequence types, suggesting multiple infection caused by either multiple mite bites, or multiple strains co-existing within individual mites.
Predicted sub-populations in a marine shrimp proteome as revealed by combined EST and cDNA data from multiple Penaeus species
Pimlapas Leekitcharoenphon, Udon Taweemuang, Prasit Palittapongarnpim, Rattanawadee Kotewong, Thararat Supasiri, Burachai Sonthayanon
BMC Research Notes , 2010, DOI: 10.1186/1756-0500-3-295
Abstract: Similarity searches from EST collections of the 4 shrimp species matched 64% of the protein sequences of the fruit fly, but only 45% of nematode proteins, indicating that the shrimp proteome content is more similar to that of an insect than a nematode. Combined results with 4 additional non-shrimp crustaceans increased matching to 78% of fruit fly and 56% of nematode proteins, suggesting that present shrimp EST collections still lack sequences for many conserved crustacean proteins. Analysis of matching data revealed the presence of 4 EST groups from shrimp, namely sequences for proteins that are both fruit fly-like and nematode-like, fruit fly-like only, nematode-like only, and non-matching. Gene ontology profiles of proteins for the 3 matching EST groups were analyzed. For non-matching ESTs, a small fraction matched protein sequences from other species in the UniProt database, including other crustacean-specific proteins.Shrimp ESTs indicated that the shrimp proteome is comprised of sub-populations of proteins similar to those common to both insect and nematode models, those present specifically in either model, or neither. Combining small EST collections from related species to compensate for their small size allowed prediction of conserved expressed protein components encoded by their uncharacterized genomes. The organized data should be useful for transferring annotation data from model species into shrimp data and for further studies on shrimp proteins with particular functions or groups.Marine shrimp (order Decapoda, family Penaeidae) are crustaceans of high economic importance, notably the Pacific whiteleg shrimp Penaeus (Litopenaeus) vannamei and the giant tiger shrimp Penaeus (Penaeus) monodon, that are prominent species in the shrimp aquaculture industry of several countries in Asia Pacific and the Americas [1]. Other species raised include Chinese shrimp Penaeus (Fenneropenaeus) chinensis and Kuruma shrimp Penaeus (Marsupenaeus) japonicus [2]. Despite th
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