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Pathogens like bacteria and protozoa, which affect human and animal health worldwide, can be transmitted by vectors like ticks. To investigate the epidemiology and genetic diversity of bacteria and protozoans carried by ticks in Chengmai county of Hainan province, China, 285 adult hard ticks belonging to two species [
Subject(s)
Animals , Anaplasmataceae/isolation & purification , Chaperonin 60/genetics , China , Citrate (si)-Synthase/genetics , Coccidia/isolation & purification , Coxiellaceae/isolation & purification , Insect Vectors/microbiology , Islands , Ixodidae/microbiology , Phylogeny , Piroplasmia/isolation & purification , RNA, Ribosomal, 16S/genetics , RNA, Ribosomal, 18S/geneticsABSTRACT
Objective To analyze the viral genetic characteristics of hantaviruses carried by Microtus maximowixzii in Yakeshi of Inner Mongolia Autonomous Region and its relationship with Hantaan virus (HTNV) and Seoul virus (SEOV) viruses as well as to identify the natural host of Khabarovsk virus (KHAV).Methods HV specific RNAs were detected by RT-PCR.Complete S and M segment were amplified from the RNA-positive samples.Phylogenetic analysis were performed to estimate the genetic characterization and the relationship with other hantaviruses.Results Fifty two Microtus maximowixzii voles were captured in Yakeshi areas.Of those voles,hanta-viral RNA was tested positive in 5 samples (9.62％).Complete S and M segments sequences were obtained from 5 and 2 lung samples,respectively.The complete S segment was consisted of 1848 to 1861 bp,and the M segment consisted of 3662 bp.These viruses were closely related to each other with 92.5％-96.4％ for the S segment sequences and 88.9％-95.4％ for the M segment sequences.They shared a higher identity with KHAV found previously in Yakeshi and KHAV of Russia.However,they were obviously different from the other hantavirus species.The 5 strains had the consistent secondary structure of nucleocapsid protein (NP) and glycoprotein (GP).When further comparing their secondary structures with those of HTNV and SEOV,our results indicated that there were no obvious differences in NP between KHAV and both HNTV,SEOV but with obvious difference in GP.Based on the S and M segment sequences,phylogenetic analyses revealed that these 5 strains clustered together with KHAV and formed a distinct lineage.Furthermore,all known KHAV strains could be divided into two small branches with a nucleotide divergence more than 5.3％.Conclusion Our research data revealed that KHAV was highly endemic among Microtus maximowixzii in Yakeshi area which supported the notion that Microtus maximowixzii had been the natural host of KHAV in the area.
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Objective To investigate the situation of the natural infection of hantaviruses (HV) in small mammals and to provide evidence for the control and prevention of hemorrhagic fever with renal syndrome (HFRS) in Longquan area,Zhejiang province. Methods Small mammals were captured by night trap, and lung tissue samples were collected and stored in liquid nitrogen. HV antigens were detected by indirect immuno-fluorescence assay (IFA). The partial S genome segment sequences were amplified by RT-PCR. DNAStar program was used for editing and comparing the sequences. Phylogeny was analyzed through PAUP*4.0 software. Results 319 small animals were collected in Longquan, and 9 hantavirus antigen-positive samples were identified. The positive rate of hantavirus in Apodemus agrarius was 4.97% . Phylogenetic tree constructed by partial S segment (620-999 nt) showed that the 9 strains carried by A agrarius from Longquan all belonged to HTNV,and had a closer evolutionary relationship with isolate Z251 from Zhejiang province. Conclusion Our results indicated that the main host was A. agrarius and the infection rate of HTNV was high in Longquan area.
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Objective To explore the role of silent information regulation 2 homolog 1 (SIRTl) in the regulation of IL-lβ mRNA transcription in lipopolysaccharide(LPS) tolerant THP-1 cells. Methods THP-1 human promonocyte model of endotoxin tolerance that simulates the sepsis leukocyte phenotype was used. Chromatin immunoprecipitation assay (ChIP) and real-timePCR were applied to quantify the binding of SIRTl and histone H3 lys9/H4 lysl6 acetylation to IL-1β promoter. IL-1β mRNA transcription was studied after knocking down the SIRTl. Results Thebinding of SIRTl to IL-1β promoter increased about 5 times in tolerant THP-1 cells (P<0.05) , which was accompanied by the low level of histone H3 lys9/H4 lysl6 acetylation (P<0.05, compared with normal cells). Knocking-down of SIRTl increased the transcription of IL-1β mRNA up to the level of 68% of normal cells (P<0.05) ,which was accompanied by the increase of histone H3 lys9/H4 lysl6 acetylation (P<0.05). However,there was no significant difference of p65 lys310 acetylation between normal and tolerant cells. Conclusion SIRTl inhibited the IL-1 β mRNA transcription in tolerant THP-1 cells but had not related to p65 lys310 acetylation. However, it was related to IL-1 p promoter acetylation.
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Objective Genetic analysis was performed to infer the relationship between hantaviruses carried by Rattus norvegicus from Henan and Neimenggu provinces and the other known hantavirus and the vaccine strain. Methods Total RNA was extracted from lung tissues with Trizol reagent. The complete M and S segment sequences of strains NM133 and Q12 were amplified by RT-PCR. The purified DNA fragments were directly subjected to sequencing, and then to sequence analysis and phylogenetic analysis. Results The complete S segment sequences of strains NM133 and Q12 were found to be 1770 nt and 1772 nt in length respectively, with one open reading frame encoding 429 amino acids. The complete M segment sequences of both two strains are 3654 nucleotide in length encoding a protein of 1133 amino acids. The two strains shared a high degree of homology with most of known Seoul virus (SEOV) but quite different from Hantaan virus and other hantaviruses. Furthermore, the nucleoprotein and glycoprotein of the two strains had the congruent structure with the vaccine strain Z37. On the S- and M-phylogenetic trees, both strains (NM133 and Q12) were grouped into the first cluster of SEOV, and were more closely related to the strains, such as: Hb8610, R22, HB55, L99, and K24-e7. Conclusion Both strains (NM133 and Q12) belonged to SEOV, and sharing a high degree of homology and similar secondary structure with strains including the vaccine strains Z37, our data suggested that the present vaccine used in China could effectively prevent HFRS caused by SEOV.
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Objective Complete S and M segments of two Seoul virus (SEOV) strains were obtained to determine their genetic types and characteristics. Methods The complete S and M segments from the isolate Li and lung tissue (sample LF18) were amplified by RT-PCR. Genetic analyses were performed by using DNAStar and PHYLIP program package. Results Their sequences consisted of 1772 nucleotides, and had an open reading frame (ORF, 43 to 1332 nt)encoding a nucleoprotein of 429 amino acids for both two strains. The complete M segment sequences consisted of 3653 nucleotides and had an ORF encoding a GnGc precursor of 1133 amino acids. The GnGc precursor of the two strains had 62 cysteine and 6 N-glycosylation sites. Both two strains shared a high degree of homology with other known SEOV strains including strains L99, Gou3, and vaccine strain Z37, with 87.6% to 99.2% and 83.6% to 97.3% nucleotide identities, respectively. On the S-and M- trees, the two strains LF18 and Li were grouped into the third cluster of SEOV. Conclusion Both LF18 and Li strains belonged to SEOV and shared the congruent genetic characteristics with the vaccine strains Z37. Thus, the bivalent vaccine including the strain Z37 could effectively prevent HFRS which was caused by SEOV in Hebei province.
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Objective Comparing the difference of virulence between the strain CGRn5310 (HTNV) and the strain HR54 (SEOV) isolated both from Rnttus norvegicus. Methods Suckling mice were used to compare the difference of virulence between the two strains. Hantavirus antigens were detected in brain and lung tissues collected from the infected mice. Results Compared with the control group, all infected mice grew slowly. Furthermore, the mice inoculated intracerebrally with either CGRn5310 or HR45 appeared ruffled fur, and reduced activity, followed by neurological symptoms, such as paralyses and convulsions. The half lethal dose (LD_(50)) of CGRn5310 strain was 10~-6.42, whereas the LD_(50) of HR54 strain was 10~-4.51. Hantavirus antigens were identified in brain and lung tissues from the mice infected with the strain CGRn5310 and the strain HR54. Conclusion LD_(50) of the strain CGRn5310 was significantly higher than that of the strain HR54. Our results suggested that the virulence of the spillover hantavirus might only slightly be influenced by the non-reservoir rodents.