1.Molecular Characterization of Hard Ticks by Cytochrome c Oxidase Subunit 1 Sequences
Huitian GOU ; Huiwen XUE ; Hong YIN ; Jianxun LUO ; Xiaolin SUN
The Korean Journal of Parasitology 2018;56(6):583-588
Although widely studied, the natural diversity of the hard tick is not well known. In this study, we collected 194 sequences from 67 species, covering 7 genera of hard tick. The 5′ region of the mitochondrial cytochrome c oxidase subunit 1 region (586 bp) has been used to investigate intra- and inter-species variation and the phylogenetic tree of neighbor joining method has been used for assessment. As a result, by comparing the K2P-distance of intra- and interspecies, 30 samples (15.2%) shown that interspecies distance was larger than the minimum interspecfic distance. From the phylogenetic analysis, 86.8% (49) of the species were identified correctly at the genus level. On deeper analysis on these species suggested the possibility of presence cryptic species. Therefore, further work is required to delineate species boundaries and to develop a more complete understanding of hard tick diversity over larger scale.
Cytochromes c
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Cytochromes
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Electron Transport Complex IV
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Ixodidae
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Methods
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Trees
2.Establishment of an indirect ELISA for detection of antibodies against Cysticercus pisiformis infection based on TPO18 protein
Zexiang WANG ; Yonglu LUO ; Ping XUE ; Liang CHE ; Yousen WANG ; Huitian GOU ; Xia-Olin SUN
Chinese Journal of Veterinary Science 2024;44(6):1213-1222
Cysticercosis,caused by the larval stage of the tapeworm Taenia pisiformis,known as Cysticercus pisiformis,is a parasitic ailment affecting lagomorphs,particularly domestic rabbits,posing a threat to the rabbit industry and the safety of rabbit meat products.This study aims to i-dentify the distribution of the TPO18 antigen in Cysticercus pisiformis and Taenia pisiformis and establish an indirect enzyme-linked immunosorbent assay(ELISA)for detecting antibodies against rabbit cysticercosis.The research involved the prokaryotic expression of the 18 kDa antigen of rabbit Cysticercus pisiformis and the isolation of soluble TPO18 protein post-purification.Immuni-zing rabbits with the TPO18 protein resulted in the production of polyclonal antibodies with a titer of up to 1∶51 200.Western blot analysis validated the antigenicity of the polyclonal antibodies a-gainst total proteins from rabbit Cysticercus pisiformis,Taenia pisiformis and the recombinant TPO18 protein.Immunohistochemistry revealed the distribution of the TPO18 antigen in rabbit Cysticercus pisiformis and Taenia pisiform is,indicating the effective reactivity of the polyclonal antibodies with total proteins from both parasites and the recombinant TPO18 protein.TPO18 an-tigen in rabbit Cysticercus pisiformis predominantly localized in the germinal layer and the paren-chyma,while in Taenia pisiformis,it was mainly present in the suckers,sucker peripheries,collec-ting duct upper cells,and parenchyma.An indirect ELISA based on the TPO18 antigen was devel-oped using the recombinant antigen,and its technical parameters were optimized.The optimized ELISA conditions included a serum dilution of 1∶100,antigen coating concentration of 5 mg/L,coating for 1 h at 37 ℃ followed by overnight incubation at 4 ℃,blocking with 1%BSA for 60 min at 37 ℃,serum reaction for 60 min,secondary antibody dilution at 1∶1 000,secondary antibody incubation for 60 min,substrate reacting for 15 min,with a cutoff value of 0.295.Sensitivity,speci-ficity,and repeatability tests of the ELISA demonstrated high sensitivity and specificity without cross-reactivity with positive sera of rabbit hemorrhagic disease virus,Hepatic coccidiosis,Eimer-ia stiedae,or Toxoplasma gondii.The intra-and inter-assay coefficients of variation were both less than 7%,indicating excellent repeatability.Application of this ELISA,compared to postmortem ex-amination,on 86 clinical serum samples showed a concordance rate of 97.7%.In conclusion,this study successfully established an indirect ELISA for detecting antibodies against rabbit Cysticercus pisiformis,presenting a novel monitoring approach for assessing rabbit infections with Cysticer-cus pisiformis.
3.Phylogenetic Analysis of Ruminant Theileria spp. from China Based on 28S Ribosomal RNA Gene.
Huitian GOU ; Guiquan GUAN ; Miling MA ; Aihong LIU ; Zhijie LIU ; Zongke XU ; Qiaoyun REN ; Youquan LI ; Jifei YANG ; Ze CHEN ; Hong YIN ; Jianxun LUO
The Korean Journal of Parasitology 2013;51(5):511-517
Species identification using DNA sequences is the basis for DNA taxonomy. In this study, we sequenced the ribosomal large-subunit RNA gene sequences (3,037-3,061 bp) in length of 13 Chinese Theileria stocks that were infective to cattle and sheep. The complete 28S rRNA gene is relatively difficult to amplify and its conserved region is not important for phylogenetic study. Therefore, we selected the D2-D3 region from the complete 28S rRNA sequences for phylogenetic analysis. Our analyses of 28S rRNA gene sequences showed that the 28S rRNA was useful as a phylogenetic marker for analyzing the relationships among Theileria spp. in ruminants. In addition, the D2-D3 region was a short segment that could be used instead of the whole 28S rRNA sequence during the phylogenetic analysis of Theileria, and it may be an ideal DNA barcode.
Animals
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Base Sequence
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China
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DNA, Ribosomal/chemistry/genetics
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Molecular Sequence Data
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Phylogeny
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RNA, Ribosomal, 28S/genetics
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Ruminants
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Sequence Alignment
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Sequence Analysis, DNA/veterinary
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Theileria/*classification/genetics/isolation & purification
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Theileriasis/*parasitology
4.Construction and biological characterization of lmo2363 gene deletion strain of Listeria monocytogenes
Ji ZHI ; Qing CAO ; Xuehui ZHAO ; Haohao ZHANG ; Ziqiu FAN ; Yonghui MA ; Jing DENG ; Zengwen HE ; Jinrui MA ; Kunzhong ZHANG ; Qian CHONG ; Caixia WANG ; Huiwen XUE ; Huitian GOU
Chinese Journal of Veterinary Science 2024;44(9):1923-1929,1956
This study aims to investigate the function of lmo2363 gene in stress resistance of Liste-ria monocytogenes strain LM83-1.In this study,the lmo2363 gene deletion strain and complement-ation strain of Listeria monocytogenes were constructed using overlapping extended PCR and ho-mologous recombination techniques,and the growth ability,stress survival rate and biofilm forma-tion ability of wild,deletion strain and complementation strain were compared under different stress environments.lmo2363 gene deletion strain and complementation strain of Listeria monocy-togenes were successfully constructed in this experiment.The growth curves showed that the growth capacity of the deletion strain was weaker than the wild strain LM83-1 under 4 ℃,7%NaCl,10%NaCl,3.5%ethanol,4.0%ethanol and pH5 stress(P<0.001).The results of stress survival test showed that the survival rate of the deletion strain was significantly lower than the wild strain after 1 h treatment with pH3 and 10 mmol/L H2 O2 stress(P<0.010).The biofilm forming ability of the deletion strain was decreased compared with that of the wild strain(P<0.050).This study confirmed that lmo2363 gene mediated the adaptation of LM to low temperature,high osmotic pressure,ethanol and acid stress environment and affected the formation of LM bio-film.This study laid a foundation for further exploring the function of lmo2363 gene in the stress resistance process of Listeria monocytogenes.