作者机构：
[Song, Hui-Qun; Lin, Rui-Qing; Zhang, Yuan; Liu, Guo-Hua; Zhu, Xing-Quan] Chinese Acad Agr Sci, Lanzhou Vet Res Inst, Key Lab Vet Parasitol Gansu Prov, State Key Lab Vet Etiol Biol, Lanzhou 730046, Gansu, Peoples R China.;[Yuan, Zi-Guo; Lin, Rui-Qing; Zhang, Yuan; Weng, Ya-Biao] S China Agr Univ, Coll Vet Med, Guangzhou 510642, Guangdong, Peoples R China.;[Liu, Guo-Hua] Hunan Agr Univ, Coll Vet Med, Changsha 410128, Hunan, Peoples R China.;[Li, Ming-Wei] Guangdong Ocean Univ, Coll Agr, Zhanjiang 524088, Guangdong, Peoples R China.;[Zhu, Xing-Quan; Zou, Feng-Cai] Yunnan Agr Univ, Coll Anim Sci & Technol, Kunming 650201, Yunnan Province, Peoples R China.
通讯机构：
[Zhu, Xing-Quan] C;Chinese Acad Agr Sci, Lanzhou Vet Res Inst, Key Lab Vet Parasitol Gansu Prov, State Key Lab Vet Etiol Biol, Lanzhou 730046, Gansu, Peoples R China.
摘要：
In this study, sequence variation in three mitochondrial DNA regions, namely cytochrome c oxidase subunit (cox1) and NADH dehydrogenase subunits 1 and 4 (nad1 and nad4), between Oesophagostomum dentatum and O. quadrispinulatum isolated from pigs in different geographical origins in Mainland China was examined, and their phylogenetic relationships were reconstructed. A partial of the cox1 (pcox1), nad1, and nad4 genes (pnad1 and pnad4) were amplified separately from individual nodule worms by PCR and were subjected to direct sequencing in order to define sequence variations. While the intraspecific sequence variations within each of the two species were 0.3-5.2% for pcox1, 0-4.9% for pnad1, and 0-7.1% for pnad4, the interspecific sequence differences were significantly higher, being 10.7-13.4% for pcox1, 11-14.6% for pnad1, and 14.9-18% for pnad4, respectively. There were a number of nucleotide positions in the pcox1, pnad1, and pnad4 sequences with no apparent intraspecific variation but distinct interspecific differences among those samples of Oesophagostomum spp. examined, which may be used as genetic makers for the identification and differentiation of the Oesophagostomum spp. Phylogenetic analyses using three inference methods, namely Bayesian inference, maximum likelihood, and maximum parsimony based on the combined sequences of pcox1, pnad1, and pnad4 revealed that the O. dentatum and O. quadrispinulatum form monophyletic groups, respectively. These findings demonstrated clearly the usefulness of the three mitochondrial sequences for studying systematics, population genetic structures, and the molecular ecology of Oesophagostomum spp.
作者机构：
[Song, Hui-Qun; Lin, Rui-Qing; Liu, Guo-Hua; Zhu, Xing-Quan] Chinese Acad Agr Sci, State Key Lab Vet Etiol Biol, Lanzhou Vet Res Inst, Key Lab Vet Parasitol Gansu Prov, Lanzhou 730046, Gansu, Peoples R China.;[Lin, Rui-Qing; Zhang, Yuan] S China Agr Univ, Coll Vet Med, Guangzhou 510642, Guangdong, Peoples R China.;[Liu, Guo-Hua; Zhu, Xing-Quan] Hunan Agr Univ, Coll Vet Med, Changsha 410128, Hunan, Peoples R China.;[Hu, Min] Huazhong Agr Univ, Coll Vet Med, State Key Lab Agr Microbiol, Wuhan 430070, Peoples R China.;[Wu, Xiang-Yun] S China Sea Inst Oceanol, Lab Marine Bioresources Sustainable Utilizat, Guangzhou 510301, Guangdong, Peoples R China.
通讯机构：
[Zhu, Xing-Quan] C;Chinese Acad Agr Sci, State Key Lab Vet Etiol Biol, Lanzhou Vet Res Inst, Key Lab Vet Parasitol Gansu Prov, Lanzhou 730046, Gansu, Peoples R China.
摘要：
A Gram-negative, rod-shaped bacterial strain named PB-CS01 which is bioluminescence-positive was isolated from contaminated commercial pork that probably had been exposed to seafood. Optimal growth of strain PB-CS01 requires the presence of 3.0% (w/v) NaCl and a temperature of 20 degrees C. Phylogenetic analysis based on 16S rRNA gene sequences of strain PB-CS01 and other Photobacterium species showed that the novel isolate belongs to the genus Photobacterium. Sequence similarity analysis between PB-CS01 and other species indicates that the closest relatives of strain PB-CS01 are Photobacterium phosphoreum ATCC 11040 (99.9%), Photobacterium kishitanii pjapo.1.1 (99.8%) and Photobacterium iliopiscarium ATCC 51760 (99.5%). The most abundant fatty acids were summed feature 3 (50.77%; C-16:1 omega 7c and/or C-16:1 omega 6c) and C-16:0 (15%). The fatty acid profile is similar to that of the genus Photobacterium but this report is the first to describe C-16:1 omega 6c as one of the compositions of summed feature 3 of the genus Photobacterium. The G+C content of the genomic DNA of strain. PB-CS01 was 44.8 mol%. Overall, strain. PB-CS01 is a novel Photobacterium species.
作者机构：
[Xu, Min-Jun; Su, Ang; Liu, Guo-Hua; Zhu, Xing-Quan] Chinese Acad Agr Sci, State Key Lab Vet Etiol Biol, Key Lab Vet Parasitol Gansu Prov, Lanzhou Vet Res Inst, Lanzhou, Gansu, Peoples R China.;[Liu, Guo-Hua; Zhu, Xing-Quan] Hunan Agr Univ, Coll Vet Med, Changsha, Hunan, Peoples R China.;[Gasser, Robin B.] Univ Melbourne, Dept Vet Sci, Werribee, Vic 3030, Australia.;[Su, Ang; Lin, Rui-Qing] S China Agr Univ, Coll Vet Med, Guangzhou, Guangdong, Peoples R China.;[Nejsum, Peter] Univ Copenhagen, Dept Vet Dis Biol, Frederiksberg, Denmark.
通讯机构：
[Liu, Guo-Hua] C;Chinese Acad Agr Sci, State Key Lab Vet Etiol Biol, Key Lab Vet Parasitol Gansu Prov, Lanzhou Vet Res Inst, Lanzhou, Gansu, Peoples R China.
摘要：
Author Summary Trichuriasis is a neglected tropical disease (NTD) caused by parasitic nematodes of the genus Trichuris (Nematoda), causing significant human and animal health problems as well as considerable socio-economic consequences world-wide. Although Trichuris species are considered to be relatively host specific, there has been significant controversy as to whether Trichuris infecting humans (recognized as T. trichiura) is a distinct species from that found in pigs (recognized as T. suis), or not. In the present study, we sequenced, annotated and compared the complete mitochondrial genomes of Trichuris from these two hosts and undertook a phylogenetic analysis of the mitochondrial datasets. This analysis showed clear genetic distinctiveness and strong statistical support for the hypothesis that T. trichiura and T. suis are separate species, consistent with previous studies using nuclear ribosomal DNA sequence data. Future studies could explore, using mitochondrial genetic markers defined in the present study, cross-transmission of Trichuris between pigs and humans in endemic regions, and the population genetics of T. trichiura and T. suis.
