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Background@#Arctic-like (AL) lineages of rabies viruses (RABVs) remains endemic in some Arctic and Asia countries. However, their evolutionary dynamics are largely unappreciated. @*Objectives@#We attempted to estimate the evolutionary history, geographic origin and spread of the Arctic-related RABVs. @*Methods@#Full length or partial sequences of the N and G genes were used to infer the evolutionary aspects of AL RABVs by Bayesian evolutionary analysis. @*Results@#The most recent common ancestor (tMRCA) of the current Arctic and AL RABVs emerged in the 1830s and evolved independently after diversification. Population demographic analysis indicated that the viruses experienced gradual growth followed by a sudden decrease in its population size from the mid-1980s to approximately 2000.Genetic flow patterns among the regions reveal a high geographic correlation in AL RABVs transmission. Discrete phylogeography suggests that the geographic origin of the AL RABVs was in east Russia in approximately the 1830s. The ancestral AL RABV then diversified and immigrated to the countries in Northeast Asia, while the viruses in South Asia were dispersed to the neighboring regions from India. The N and G genes of RABVs in both clades sustained high levels of purifying selection, and the positive selection sites were mainly found on the C-terminus of the G gene. @*Conclusions@#The current AL RABVs circulating in South and North Asia evolved and dispersed independently.
ABSTRACT
Background@#High concentrations of particulate matter less than 2.5 μm in diameter (PM2.5) in poultry houses is an important cause of respiratory disease in animals and humans. Pseudomonas aeruginosa is an opportunistic pathogen that can induce severe respiratory disease in animals under stress or with abnormal immune functions. When excessively high concentrations of PM2.5 in poultry houses damage the respiratory system and impair host immunity, secondary infections with P. aeruginosa can occur and produce a more intense inflammatory response, resulting in more severe lung injury. @*Objectives@#In this study, we focused on the synergistic induction of inflammatory injury in the respiratory system and the related molecular mechanisms induced by PM2.5 and P. aeruginosa in poultry houses. @*Methods@#High-throughput 16S rDNA sequence analysis was used for characterizing the bacterial diversity and relative abundance of the PM2.5 samples, and the effects of PM2.5 and P. aeruginosa stimulation on inflammation were detected by in vitro and in vivo. @*Results@#Sequencing results indicated that the PM2.5 in poultry houses contained a high abundance of potentially pathogenic genera, such as Pseudomonas (2.94%). The lung tissues of mice had more significant pathological damage when co-stimulated by PM2.5 and P. aeruginosa, and it can increase the expression levels of interleukin (IL)-6, IL-8, and tumor necrosis factor-α through nuclear factor (NF)-κB pathway in vivo and in vitro. @*Conclusions@#The results confirmed that poultry house PM2.5 in combination with P. aeruginosa could aggravate the inflammatory response and cause more severe respiratory system injuries through a process closely related to the activation of the NF-κB pathway.
ABSTRACT
Salmonella enterica serovar Enteritidis (SE) is one of the most important zoonotic pathogens that cause enteritis and systemic infection in animals and human. Understanding invasive capacities of SE isolates is of vital importance to elucidate pathogenesis of Salmonella infection. To improve the throughput capacity and repeatability of classical gentamicin protection assay (GPA), a modified PGA was developed by taking high-throughput advantage of 96-well cell plates and multichannel pipettes. In addition, drop plate technique rather than spread plate method was applied in the modified GPA protocol for bacterial enumeration. The modified GPA protocol was evaluated by phenotyping intracellular replication of a high virulent and a low virulent SE isolates, JL228 and LN248, in a phagocytic cell line RAW264.7. The protocol was then applied in invasive phenotype determination of 16 SE strains to non-phagocytes (HT-29) and the intracellular replication of 43 SE strains to phagocytes (RAW264.7). Significant lower intra-group and inter-group coefficient of variations of the modified GPA was observed, implying good repeatability and reproducibility over traditional protocol. Further, replication phenotypes were also correlated with those from direct observation by confocal microscopy. Collectively, the improved GPA protocol had advantages of high throughput capacity, good repeatability and reliability, it was also noticed that the protocol also represented a fast and labor-saving alternative scheme for the invasive phenotype determination of Salmonella Enteritidis, and providing reliable phenotype profiles for Salmonella-host interplay interpretation.
Subject(s)
Animals , Humans , Gentamicins/pharmacology , Phenotype , Reproducibility of Results , Salmonella Infections, Animal , Salmonella enteritidisABSTRACT
Herpesvirus infections in Cervidae are a serious threat affecting some deer species worldwide. In our attempt to identify malignant catarrhal fever-associated herpesviruses in deer herds, ten gammaherpesviral DNA fragments were identified in five species of deer in herds in China by using a pan-herpesvirus polymerase chain reaction assay targeting viral DNA polymerase. Notably, in sambar (Rusa unicolor), a novel gamma-2 herpesvirus was identified that showed a close relationship with fallow deer lymphotropic herpesvirus (LHV), while the other fragments were phylogenetically grouped together with Elk-LHV. Determination of whether these viruses have any clinical implication in these deer species should be undertaken urgently.
Subject(s)
Animals , Cattle , China , Deer , DNA , DNA, Viral , Herpesviridae Infections , Herpesviridae , Malignant Catarrh , Polymerase Chain ReactionABSTRACT
To investigate the relationship of the variation of virulence and the external capsid proteins of the pandemic duck hepatitis A virus type 1(DHAV-1) isolates,the virulence,cross neutralization assays and the complete sequence of the virion protein 1(VP1) gene of nine virulent DHAV-1 strains,which were isolated from infected ducklings with clinical symptoms in Shandong province of China in 2007-2008,were tested.The fifth generation duck embryo allantoic liquids of the 9 isolates were tested on 12-day-old duck embryos and on 7-day-old ducklings for the median embryonal lethal doses(ELD50s) and the median lethal doses(LD50s),respectively.The results showed that the ELD5s of embryonic duck eggs of the 9 DHAV-1 isolates were between 1.9 × 106/mL to 1.44 × 107/mL,while the LD50s were 2.39 × 105/mL to 6.15 × 106/mL.Cross-neutralization tests revealed that the 9 DHAV-1 isolates were completely neutralized by the standard serum and the hyperimmune sera against the 9 DHAV-1 isolates,respectively.Compared with other virulent,moderate virulent,attenuated vaccine and mild strains,the VP1 genes of the 9 strains shared 89.8％-99.7％ similarity at the nucleotide level and 92.4％-99.6％ at amino acid level with other DHAV-1 strains.There were three hypervariable regions at the C-terminus(as 158-160,180-193 and 205-219) and other variable points in VPI protein,but which didn't cause virulence of DHAV-1 change.
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To investigate molecular epidemiology of DuCV in Cherry Valley ducks in China,the complete genomes of six DuCV strains,which were detected from Cherry Valley ducks in China between 2007 and 2008,were sequenced.Sequence and phylogenetic analysis were carried out to compare these six strains with another 27DuCV strains from Mulard duck,Muscovy duck,Pekin ducks and Mule duck.The analysis showed that the six DuCV strains exhibited typical genetic features of the family of DuCV,such as a stem-loop structure,three major open reading frames (Rep,Cap and ORF3),four intergenic repeats and the conserved motifs for rolling circle replication and for the dNTP binding domain located in the Rep protein.Phylogenetic analysis of the nucleotide sequences of the complete genome and Cap gene of these strains together with those that have been previously published demonstrated two distinct DuCV genotypes.The DuCV strains with complete genomes containing 1988and 1989 nucleotides clustered in genotype A,whereas the strains with complete genomes containing 1991,1992,1995 and 1996 nucleotides lay in genotype B.The six DuCV strains from Cherry Valley ducks were divided into the two groups.The results of the study provides some insight into the variation of DuCVs in Cherry Valley ducks.
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The duck circovirus (DuCV) infection in sick ducks from Fujian Province was investigated. The liver samples of 43 sick Muscovy ducks with infectious serositis were collected from 12 duck farms in Fujian Province.Based on the published sequences of DuCV, two primers were designed for the detection of DuCV and four pairs of primers were designed to amplify four overlapping fragments that cover the complete genome of DuCV. The specific PCR products were amplified from positive samples. The fragments were then cloned into pMD18-T vector and sequenced, and the full length genomic sequence of the FJ0601 isolate of DuCV was obtained. PCR analysis showed that the proportion of ducks which were positive for circovirus was 79% and 10 out of the 12 farms were positive. Sequence analysis showed that the complete genome of DuCV-FJ0601 was 1988 bp and possessed features common to the family Circoviridae which included a stem-loop structure and the Rep protein motifs. Homology analysis showed that FJ0601 isolate of DuCV had 97.3%～97.5% nucleotide sequence identity to all the four Taiwan isolates (TC1/2002, TC2/2002, TC3/2002, TC4/2002), 82.9% identity to the America (33753-52) isolate and 82.3% identity to the Germany isolate. Phylogenetic analysis with Clustal W, however,showed that FJ0601 isolate of DuCV was on a common branch with Taiwan isolates, and Germany and America isolates belonged to the other branch.