Analysis of Cellular Fatty Acids in Orientia tsutsugamushi as Taxonomic Markers

Abstract

Six Orientia strains including 3 prototype strains such as Gilliam, Karp, and Kato, and 3 strains (Boryong, Pajoo, and Yongworl) isolated in Korea, were studied for the profiles of their cellular fatty acids. All tested strains contained octadecenoic acid C18:1 ω3±3.5%), octadecanoic acid C18:0 (15.3±1.5%), and hexadecanoic acid C16:0 (12.7±1.7%) as major components; however, interestingly, eicosenoic acid C20:1 ω9c (2.6 ±0.6%) was found in all strains except the Yongworl strain. Furthermore none of the strains contained 3‐hydroxy fatty acids. The ratios of total saturated fatty acid (SFA) to total unsaturated fatty acid (UFA) were within the range of 0.34 to 0.54. These results showed that the cellular fatty acid profile should provide more reliable information for the identification of these bacteria.

Prevalence of chigger mites and Orientia tsutsugamushi strains in northern regions of Gangwon-do, Korea

“…Several strains of O. tsutsugamushi have been documented in Korea, including the 3 prototype strains, Gilliam, Karp, and Kato, as well as 3 native strains (Boryong, Pajoo, and Youngworl). Boryong is the most prominent strain and has been documented in the central and southern parts of Korea; Gilliam, Karp, Kato, Pajoo, and Youngworl strains have also been identified in the central region [10,[24][25][26]. These results suggest that there is a correlation between the distribution of O. tsutsugamushi strains, and the population density and vector competence of chigger mites.…”

“…The chigger mite is one of the most medically significant outdoor mites in Korea, and it mediates scrub typhus, which occurs annually and presents a public health hazard [ 1 – 7 ]. Chigger mites, L. pallidum and L. scutellare , are recognized as the primary vectors of scrub typhus in Korea.…”

“…The chigger mite is one of the most medically significant outdoor mites in Korea, and it mediates scrub typhus, which occurs annually and presents a public health hazard [1][2][3][4][5][6][7].…”

“…O. tsutsugamushi has 3 primary prototypes: Karp, Gilliam, and Kato serotypes [6]. Several strains of O. tsutsugamushi have been recorded in Parasites Hosts Dis 2023;61(3):263-271 • https//doi.org/10.3347/PHD.22148 Korea, including the 3 important prototype strains Gilliam, Karp, and Kato, as well as strains (Boryong, Wonju, Jecheon, Pajoo, and Youngworl, Kanda, Oishi, OI011, Taguchi, and Shimokoshi) [7][8][9]. The Boryong strain is found in the southern and central parts of Korea, whereas the Gilliam, Karp, and Pajoo strains are mostly found in the central region [10].…”

Phylogenetic clustering of 4 prevalent virulence genes in Orientia tsutsugamushi isolates from human patients

“…Also, variant serotypes have been reported in China, Japan, Thailand, and other Asian countries (Enatsu et al, 1999;Qiang et al, 2003;Blacksell et al, 2008). Some other strains such as the Yongworl, Pajoo, and Yonchon are identified as causative agents of O. tsutsugamushi in Korea (Chang et al, 1990;Seong et al, 1997;Shim et al, 2005;Yamashita et al, 1988). 56 kDa protein antigen is a primary antigen found in the sera of humans infected with scrub typhus.…”