evaluation-universal-nested-reverse-transcription-polymerase-chain

Evaluation of a Universal Nested Reverse Transcription Polymerase Chain Reaction for the Detection of Lyssaviruses

To detect rabies virus and other member species of the genus Lyssavirus within the family Rhabdoviridae, the pan-lyssavirus nested reverse transcription ...

Academy of Military Medical Sciences

Jiangsu Co-innovation Centre for Prevention and Control of Important Animal Infectious Diseases and Zoonoses

Ticks are implicated in the transmission of various human and livestock pathogens worldwide. This study aimed to understand the geographical distribution of tick species, along with tick-associated viruses, in Heilongjiang Province, northeast China. Molecular methods were used to classify tick species, with next-generation sequencing and polymerase chain reaction-based analyses used to assess the viromes of ticks from four representative sampling locations in the Greater Khingan Mountains. Five species of ixodid ticks were identified, including Ixodes persulcatus, Dermacentor nuttalli, Dermacentor silvarum, Haemaphysalis longicornis, and Haemaphysalis concinna. From the 1102 ticks, 3,568,561 high-quality reads were obtained by next-generation sequencing. Following trimming, 302,540 reads were obtained, of which 6577 (2.16%) reads were annotated to viruses. Phylogenetic analysis revealed that the viral sequences shared a close relationship with Orthonairovirus, Phlebovirus, deer tick Mononegavirales-like virus, and Jingmen tick virus sequences, but the significance of these newly-identified tick-borne viruses to human and animal health requires further investigation. The results of this study provide a basis not only for further studies on the relationship between ticks and tick-borne viruses, but also for preventing future tick-borne epidemic outbreaks by means of vector control.

Virome analysis of tick-borne viruses in Heilongjiang Province, China.

Rodents, as the most diverse and widest distributed mammals, are a natural reservoir of many zoonotic viruses. However, little is known about the viral diversity harbored by rodents in China. Here we performed viral metagenomic analyses of 314 wild rodents covering 7 species, sampled in North-western China. We also conducted a systematic virological characterization of a new Wenzhou virus (WENV) isolate, QARn1, from a brown rat (Rattus norvegicus). Full genomic and phylogenetic analyses showed that QARn1 is a previously unidentified strain of Wenzhou mammarenavirus and forms a new branch within the Asian clade. Experimental infection of Sprague-Dawley rats with QARn1 did not present overt pathology, but specific humoral immune responses developed and mild hemorrhage and immunocyte infiltration of the lungs and thymus were observed. These observations have expanded the geographic distribution of WENV to Central Asia, and further confirm that brown rats are natural hosts of Wenzhou virus.

Virome profiling of rodents in Xinjiang Uygur Autonomous Region, China: Isolation and characterization of a new strain of Wenzhou virus.

Classical swine fever (CSF) remains an important pig disease in China, where it usually presents with mild or atypical clinical manifestations, with large scale outbreaks rarely seen. This has led to speculation about the possible circulation of viral strains of low virulence. To investigate this possibility, five field isolates within the predominant genotype 2 (2.1b, 2.1c, 2.1 h and 2.2) were evaluated and compared by experimental infection of naturally farrowed but colostrum-deprived piglets. All infected piglets displayed clinical signs, including persistent high fever, depression, anorexia, dyspnea, conjunctivitis, constipation, and hesitant gait. Typical pathological lesions, including pulmonary edema, hemorrhagic or cellulosic exudation, and swelling and hemorrhage of lymph nodes, were observed. Viremia and E protein expression in the blood of all infected animals were detectable from 3 to 5 days post infection (DPI), their presence correlating with the onset of fever, clinical signs and leukopenia. E2 antibody did not develop in any of the field CSFV-infected piglets during the disease course, while E antibody was detectable in 4-56% of infected animals at various time points. Mortalities ranged from 20 to 80% within 21 DPI, progressing to 100% by 43 DPI. Based on clinical scores and fatalities within 21 DPI, 2 of the 5 field isolates were classified as of moderate virulence and 3 of high virulence; i.e., no field isolates of low virulence were identified. The study has provided data supporting the use of these isolates as challenge viruses to evaluate the efficacy of current CSF vaccines.

Changchun Tu

Key Laboratory of Jilin Province for Zoonosis Prevention and Control,
Institute of Military Veterinary Medicine,
Key Laboratory of Jilin Province for Zoonosis Prevention and Control, Institute of Military Veterinary Medicine

Academy of Military Medical Sciences

Evaluation of a Universal Nested Reverse Transcription Polymerase Chain Reaction for the Detection of Lyssaviruses