Complete Mitochondrial Genome of a Tongue Worm Armillifer agkistrodontis

Armillifer agkistrodontis (Ichthyostraca: Pantastomida) is a parasitic pathogen, only reported in China, which can cause a zoonotic disease, pentastomiasis. A complete mitochondrial (mt) genome was 16,521 bp comprising 13 protein-coding genes (PCGs), 22 tRNA genes, 2 rRNA genes, and 1 non-coding region (NCR). A phylogenetic tree drawn with the concatenated amino acid sequences of the 6 conserved PCGs (atp6, cox1-3, and nad2) showed that A. agkistrodontis and Armillifer armillatus constituted a clade Pentastomida which was a sister group of the Branchiura. The complete mt genome sequence of A. agkistrodontis provides important genetic markers for both phylogenetic and epidemiological studies of pentastomids.

Dynamics of specific antibody and circulating antigen in serum from the mice infected with Armillifer agkistrodontis / 中国人兽共患病学报

In this study,adults of Armillifer agkistrodontis (A.agkistrodontis) were collected from Agkistrodon acutus,and then the eggs were separated to feed mice.In the next step,when the infection model was established,blood serum of infected mice were collected after 1,2 and 3 weeks,respectively.Furthermore,ELISA and dot- ELISA were used to detect the dynamic change of specific antibodies and circulating antigens respectively.The specific antibodies increased from 8th week,reached the top at 12th week,decreased from 16th week,and then maintain at the same level constantly.Meanwhile,the specific antibodies were typed.It is evident that IgM antibody appeared first.However,it was substitute by IgG1 after 16 weeks.Moreover,the circulating antigens have been detected in the 1st week by dot-ELISA.Then,the dilution between 1:8 to 1:128were founded in 3rd week.The highest dilution with 1:256 appeared at 8th week,maintained before 11th week and then decreased gradually,which might provide a significant clinical implication for early diagnosis of circulating antigens.

Construction and immunoscreening of cDNA library of Armillifer agkistrodontis nymphs / 中国地方病学杂志

Objective To construct cDNA entry library and cDNA expression library of Armillifer agkistrodontis (A.) nymphs and make a preliminary immunoscreening for the cDNA expression library.Methods The nymphs were collected from the Kunming mice infected experimentally with A.agkistrodontis eggs and the total RNA were extracted from the nymphs using TRIzol Reagent.After purifying the mRNA,the synthesized cDNAs were cloned into the donor vector pDONR222 by BP reaction of Gateway technology and the recombinants were transformed into the DH10B cells by electroporation,the cDNA entry library was obtained.Next,the expression vector pDEST17 was ligated with entry clones by LR reaction,and the recombinants were transformed into the BL21 (DE3) cells.Hence,the cDNA expression library was constructed.Then,the expression library was immunoscreened with the mixed sera of mice infected with A.agkistrodontis,and the insertions of positive clones were sequenced.After that,the open reading frame(ORF) of positive slone sequence,the homology of the screened genes and their encoded proteins were analyzed by Finder and BLAST (basic local alignment search tool) program of National Center of Biotechnology Information(NCBI),and the discovered new genes were submitted into the GenBank.Besides,the physico-chemical properties,secondary structure and B cell epitopes of encoded proteins were also analyzed by bioinformatics software.Results The average titer and total clones of the cDNA entry library were 1.45 × 105 CFU/ml(colony-forming unit,CFU) and 1.74 × 106 CFU,respectively,and the range of fragment length of the inserted cDNA was between 0.2-4.0 kb,with an average of 1.4 kb.The total clones of cDNA expression library were 1.00 × 105 CFU,and the fragment length of the inserted cDNA was between 0.3-2.2 kb,with an average of 1.0 kb.Five positive clones,coded S1,S5,A1,D1 and F1,respectively,were obtained through preliminary immunoscreening.The sequence and homology of the five positive clones were sequenced and analyzed by BLAST program.No significant similarities were found in pentastomida species,which meant that they were all novel genes of A.agkistrodontis.The gene sequences were submitted to GenBank,with the accession number from JQ180451 to JQ180455.Also,results obtained by bioinformatics software showed that the predictive encoding proteins were all potential to be valuable recombinant diagnostic antigens.Conclusions The cDNA library of A.agkistrodontis nymphs is successfully constructed,and five new genes of A.agkistrodontis are discovered.The establishment of cDNA library and the discovery of the new genes will lay a foundation for further studying the gene functions and screening the immunodiagnostic antigens.