A novel mRNA rabies vaccine as a promising candidate for rabies post-exposure prophylaxis protects animals from different rabies viruses.

Rabies, caused by the rabies virus (RABV), is the most fatal zoonotic disease. It is a neglected tropical disease which remains a major public health problem, causing approximately 59,000 deaths worldwide annually. Despite the existence of effective vaccines, the high incidence of human rabies is mainly linked to tedious vaccine immunisation procedures and the overall high cost of post-exposure prophylaxis. Therefore, it is necessary to develop an effective vaccine that has a simple procedure and is affordable to prevent rabies infection in humans. RABV belongs to the genus Lyssavirus and family Rhabdoviridae. Previous phylogenetic analyses have identified seven major clades of RABV in China (China I-VII), confirmed by analysing nucleotide sequences from both the G and N proteins. This study evaluated the immunogenicity and protective capacity of SYS6008, an mRNA rabies vaccine expressing rabies virus glycoprotein, in mice and cynomolgus macaques. We demonstrated that SYS6008 induced sufficient levels of rabies neutralising antibody (RVNA) in mice. In addition, SYS6008 elicited strong and durable RVNA responses in vaccinated cynomolgus macaques. In the pre-exposure prophylaxis murine model, one or two injections of SYS6008 at 1/10 or 1/30 of dosage provided protection against a challenge with a 30-fold LD50 of rabies virus (China I and II clades). We also demonstrated that in the post-exposure prophylaxis murine model, which was exposed to lethal rabies virus (China I-VII clades) before vaccination, one or two injections of SYS6008 at both 1/10 and 1/30 dosages provided better protection against rabies virus challenge than the immunization by five injections of commercial vaccines at the same dosage. In addition, we proved that SYS6008-induced RVNAs could neutralise RABV from the China I-VII clades. Finally, 1/10 of the dosage of SYS6008 was able to stimulate significant RABV-G specificity in the T cell response. Furthermore, we found that SYS6008 induced high cellular immunity, including RABV-G-specific T cell responses and memory B cells. Our results imply that the SYS6008 rabies vaccine, with a much simpler vaccination procedure, better immunogenicity, and enhanced protective capacity, could be a candidate vaccine for post-exposure prophylaxis of rabies infections.

Bardoxolone methyl inhibits the infection of rabies virus via Nrf2 pathway activation in vitro.

BACKGROUND: Rabies is a widespread, fatal, infectious disease. Several antivirals against rabies virus (RABV) infection have been reported, but no approved, RABV-specific antiviral drugs that inhibit RABV infection in the clinic after symptom onset are available. Therefore, more effective drugs to reduce rabies fatalities are urgently needed. Bardoxolone methyl (CDDO-Me), an FDA-approved compound that has long been known as an antioxidant inflammatory modulator and one of the most potent nuclear factor erythroid-derived 2-like 2 (Nrf2) activators, protects myelin, axons, and CNS neurons by Nrf2 activation. Therefore, we investigated the potency of its anti-RABV activity in vitro. METHODS: The mouse neuroblastoma cell line Neuro2a (N2a) and three RABV strains of different virulence were used; the cytotoxicity and anti-RABV activity of CDDO-Me in N2a cells were evaluated by CCK-8 assay and direct fluorescent antibody (DFA) assay. Pathway activation in N2a cells infected with the RABV strains SC16, CVS-11 or CTN upon CDDO-Me treatment was evaluated by western blotting (WB) and DFA assay. RESULTS: CDDO-Me significantly inhibited infection of the three RABV strains of differing virulence (SC16, CVS-11 and CTN) in N2a cells. We also examined whether CDDO-Me activates the Nrf2-associated pathway upon infection with RABV strains of differing virulence. Nrf2, phosphorylated sequestosome (SQSTM1), SQSTM1, hemoglobin oxygenase (HO-1) and NAD(P)H dehydrogenase quinone 1 (NQO1) expression in N2a cells increased to varying degrees with CDDO-Me treatment, accompanied by Kelch-like ECH-associated protein 1 (Keap1) dissociation, upon infection with SC16, CVS-11 or CTN. The activation of SQSTM1 phosphorylation was significantly associated with the degradation of Keap-1 in CDDO-Me-treated N2a cells upon RABV infection. Furthermore, N2a cells pretreated with the Nrf2-specific inhibitor ATRA showed a significant decrease in HO-1 and NQO1 expression and a decrease in the anti-RABV efficacy of CDDO-Me. These inhibitory effects were observed upon infection with three RABV strains of differing virulence. CONCLUSION: CDDO-Me inhibited RABV infection via Nrf2 activation, promoting a cytoprotective defense response in N2a cells. Our study provides a therapeutic strategy for RABV inhibition and neuroprotection during viral infection.

Inflammatory response and MAPK and NF-κB pathway activation induced by natural street rabies virus infection in the brain tissues of dogs and humans.

BACKGROUND: Street rabies virus (RABV) usually infects hosts at peripheral sites and migrates from motor or sensory nerves to the central nervous system. Several studies have found that inflammation is mild in a mouse model of street RABV infection. However, the pathogenetic mechanisms of street RABV in naturally infected dogs or humans are not well understood. METHODS: Brain tissues collected from 3 dogs and 3 humans were used; these tissue samples were collected under the natural condition of rabies-induced death. The inflammatory response and pathway activation in the brain tissue samples of dogs and humans were evaluated by HE, IHC, ARY006, WB and ELISA. The clinical isolate street RABV strains CGS-17 and CXZ-15 from 30 six-week-old ICR mice were used to construct the mouse infection model presented here. RESULTS: Neuronal degeneration and increased lymphocyte infiltration in the cerebral cortex, especially marked activation of microglia, formation of glial nodules, and neuronophagy, were observed in the dogs and humans infected with the street RABV strains. The various levels of proinflammatory chemokines, particularly CXCL1, CXCL12, CCL2, and CCL5, were increased significantly in the context of infection with street RABV strains in dogs and humans in relation to healthy controls, and the levels of MAPK and NF-κB phosphorylation were also increased in dogs and humans with natural infection. We also found that the degrees of pathological change, inflammatory response, MAPK and NF-κB signaling pathway activation were obviously increased during natural infection in dogs and humans compared with artificial model infection in mice. CONCLUSION: The data obtained here provide direct evidence for the RABV-induced activation of the inflammatory response in a dog infection model, which is a relatively accurate reflection of the pathogenic mechanism of human street RABV infection. These observations provide insight into the precise roles of underlying mechanisms in fatal natural RABV infection.

The Adverse Effect of the 2-1-1 Regimen for Rabies PEP in Preschool Children.

Post-exposure prophylaxis (PEP) has proved to be the most important measure for rabies prevention and control. There is little information regarding adverse reactions to the Essen and 2-1-1 regimens in preschool children (aged 0-6). We reexamined the outcomes of 1,109 preschool children who were vaccinated using SPEEDA under the Essen regimen between January 2011 and December 2012 and 1,267 preschool children under the 2-1-1 regimen between January 2013 and December 2014. We find that, in preschool children, the febrile reaction after the first 2-dose injection in the 2-1-1 regimen was significantly higher than that induced by the first 1-dose in the Essen procedure. Thus, we recommend that the Essen regimen should still be used for rabies PEP in preschool children.

Whole Genome Sequencing and Comparisons of Different Chinese Rabies Virus Lineages Including the First Complete Genome of an Arctic-like Strain in China.

OBJECTIVE: To learn the rabies genome molecular characteristics and compare the difference of China rabies lineages. METHODS: The complete genomes of 12 strains from different China rabies lineages were amplified and sequenced, and all the China street strain genomes (total 43), Arctic and Arctic-like genomes were aligned using ClustalX2, the genome homologies were analyzed using MegAlign software, and the phylogenetic trees were constructed by MEGA 5. RESULTS: First Arctic-like rabies genome in China (CQH1202D) was reported, and we supplemented the rabies genome data of China, ensuring at least one genome was available in each China lineage. The genome size of China V (11908nt) is obviously shorter than other lineages' (11923-11925nt) for the difference of N-P non-coding regions. Among different lineages, the genome homologies are almost under 90%. CQH1202D (China IV lineage) has close relationship with strains from South Korea and they share about 95% genome similarities. CONCLUSION: The molecular characteristics of 6 different China rabies lineages were compared and analyzed from genome level, which benefits for continued comprehensive rabies surveillance, rabies prevention and control in China.

Enhancement of Virus Replication in An Influenza A Virus NS1-Expresssing 293 Cell Line.

The nonstructural protein 1 (NS1) of influenza A virus, which is absent from the viral particle, but highly expressed in infected cells, strongly antagonizes the interferon (IFN)-mediated antiviral response. We engineered an NS1-expressing 293 (293-NS1) cell line with no response to IFN stimulation. Compared with the parental 293 cells, the IFN-nonresponsive 293-NS1 cells improved the growth capacity of various viruses, but the introduction of NS1 barely enhanced the propagation of Tahyna virus, a negative-strand RNA virus. In particular, fastidious enteric adenovirus that replicates poorly in 293 cells may grow more efficiently in 293-NS1 cells; thus, IFN-nonresponsive 293-NS1 cells might be of great value in diagnostic laboratories for the cultivation and isolation of human enteric adenoviruses.

Comparative Study on the Immunogenicity and Efficacy of Different Post-exposure Intramuscular Rabies Vaccination Regimens in China.

Objective: This study aimed to compare the current Essen rabies post-exposure immunization schedule (0-3-7-14-28) in China and the simple 4-dose schedule (0-3-7-14) newly recommended by the World Health Organization in terms of their safety, efficacy, and protection. Methods: Mice were vaccinated according to different immunization schedules, and blood was collected for detection of rabies virus neutralizing antibodies (RVNAs) on days 14, 21, 28, 35, and 120 after the first immunization. Additionally, different groups of mice were injected with lethal doses of the CVS-11 virus on day 0, subjected to different rabies immunization schedules, and assessed for morbidity and death status. In a clinical trial, 185 rabies-exposed individuals were selected for post-exposure vaccination according to the Essen schedule, and blood was collected for RVNAs detection on days 28 and 42 after the first immunization. Results: A statistically significant difference in RVNAs between mice in the Essen and 0-3-7-14 schedule groups was observed on the 35th day ( P < 0.05). The groups 0-3-7-14, 0-3-7-21, and 0-3-7-28 showed no statistically significant difference ( P > 0.05) in RVNAs levels at any time point. The post-exposure immune protective test showed that the survival rate of mice in the control group was 20%, whereas that in the immunization groups was 40%. In the clinical trial, the RVNAs positive conversion rates on days 28 (14 days after 4 doses) and 42 (14 days after 5 doses) were both 100%, and no significant difference in RVNAs levels was observed ( P > 0.05). Conclusion: The simple 4-dose schedule can produce sufficient RVNAs levels, with no significant effect of a delayed fourth vaccine dose (14-28 d) on the immunization potential.

BCX4430 inhibits the replication of rabies virus by suppressing mTOR-dependent autophagy invitro.

Rabies is a fatal neurological infectious disease caused by rabies virus (RABV). However, no effective anti-RABV drugs for treatment during the symptomatic phase are available. The novel adenosine nucleoside analog galidesivir (BCX4430) has broad-spectrum activity against a wide variety of highly pathogenic RNA viruses. In this study, we observed no apparent cytotoxicity of BCX4430 at the highest concentration of 250 µΜ, and which was displayed stronger antiviral activity against different virulent RABV in N2a or BHK-21 cells until 72 hpi. Meanwhile, BCX4430 showed greater anti-RABV activity than T-705 and anti-RABV activity similar to that of ribavirin in N2a cells. Furthermore, BCX4430 dose- and time-dependently inhibited RABV replication via mTOR-dependent autophagy inhibition in N2a cells with increased phospho-mTOR and phospho-SQSTM1 and decreased LC3-II levels. Taken together, these findings suggest that BCX4430 has potent anti-RABV activity in vitro and might provide a basis for the development of novel drug therapies against RABV.

Current status of canine rabies in China.

The number of human rabies cases acquired from dog bites constitutes a high proportion of the total rabies cases in China, although the number of human rabies cases has gradually decreased in recent years. The pivotal role of dogs in the spread of rabies indicates that controlling and preventing canine rabies could be a key step in eradicating human rabies in China. The primary aims of this review are to discuss the properties and pathogenesis of the rabies virus, the clinical signs and diagnosis of canine rabies, threshold host density and vaccination of dogs, and the prevention and control of canine rabies in China.

Isolation of a Novel Bat Rhabdovirus with Evidence of Human Exposure in China.

Bats are well-recognized reservoirs of zoonotic viruses. Several spillover events from bats to humans have been reported, causing severe epidemic or endemic diseases including severe acute respiratory syndrome-coronavirus 2 (SARS-CoV-2), SARS-CoV, Middle East respiratory syndrome-CoV (MERS-CoV), henipaviruses, and filoviruses. In this study, a novel rhabdovirus species, provisionally named Rhinolophus rhabdovirus DPuer (DPRV), was identified from the horseshoe bat (Rhinolophus affinis) in Yunnan province, China, using next-generation sequencing. DPRV shedding in the spleen, liver, lung, and intestinal contents of wild bats with high viral loads was detected by real-time quantitative PCR, indicating that DPRV has tropism for multiple host tissues. Furthermore, DPRV can replicate in vitro in multiple mammalian cell lines, including BHK-21, A549, and MA104 cells, with the highest efficiency in hamster kidney cell line BHK-21, suggesting infectivity of DPRV in these cell line-derived hosts. Ultrastructure analysis revealed a characteristic bullet-shaped morphology and tightly clustered distribution of DPRV particles in the intracellular space. DPRV replicated efficiently in suckling mouse brains and caused death of suckling mice; death rates increased with passaging of DPRV in suckling mice. Moreover, 421 serum samples were collected from individuals who lived near the bat collection site and had fever symptoms within 1 year. DPRV-specific antibodies were detected in 20 (4.75%) human serum samples by indirect immunofluorescence assay. Furthermore, 10 (2.38%) serum samples were DPRV positive according to plaque reduction neutralization assay, which revealed potential transmission of DPRV from bats to humans and highlighted the potential public health risk. Potential vector association with DPRV was not found with negative viral RNA in bloodsucking arthropods. IMPORTANCE We identified a novel rhabdovirus from the horseshoe bat (Rhinolophus thomasi) in China with probable infectivity in humans. DPRV was isolated in vitro from several mammalian cell lines, indicating wide host tropism, excluding bats, of DPRV. DPRV replicated in the brains of suckling mice, and the death rate of suckling mice increased with passaging of DPRV in vivo. Serological tests indicated the possible infectivity of DPRV in humans and the potential transmission to humans. The present findings provide preliminary evidence for the potential risk of DPRV to public health. Additional studies with active surveillance are needed to address interspecies transmission and determine the pathogenicity of DPRV in humans.

Evaluation of the Safety and Immune Efficacy of Recombinant Human Respiratory Syncytial Virus Strain Long Live Attenuated Vaccine Candidates.

Human respiratory syncytial virus (RSV) infection is the leading cause of lower respiratory tract illness (LRTI), and no vaccine against LRTI has proven to be safe and effective in infants. Our study assessed attenuated recombinant RSVs as vaccine candidates to prevent RSV infection in mice. The constructed recombinant plasmids harbored (5' to 3') a T7 promoter, hammerhead ribozyme, RSV Long strain antigenomic cDNA with cold-passaged (cp) mutations or cp combined with temperature-sensitive attenuated mutations from the A2 strain (A2cpts) or further combined with SH gene deletion (A2cptsΔSH), HDV ribozyme (δ), and a T7 terminator. These vectors were subsequently co-transfected with four helper plasmids encoding N, P, L, and M2-1 viral proteins into BHK/T7-9 cells, and the recovered viruses were then passaged in Vero cells. The rescued recombinant RSVs (rRSVs) were named rRSV-Long/A2cp, rRSV-Long/A2cpts, and rRSV-Long/A2cptsΔSH, respectively, and stably passaged in vitro, without reversion to wild type (wt) at sites containing introduced mutations or deletion. Although rRSV-Long/A2cpts and rRSV-Long/A2cptsΔSH displayed  temperature-sensitive (ts) phenotype in vitro and in vivo, all rRSVs were significantly attenuated in vivo. Furthermore, BALB/c mice immunized with rRSVs produced Th1-biased immune response, resisted wtRSV infection, and were free from enhanced respiratory disease. We showed that the combination of ΔSH with attenuation (att) mutations of cpts contributed to improving att phenotype, efficacy, and gene stability of rRSV. By successfully introducing att mutations and SH gene deletion into the RSV Long parent and producing three rRSV strains, we have laid an important foundation for the development of RSV live attenuated vaccines.

Rabies viruses of different virulence regulates inflammatory responses both in vivo and in vitro via MAPK and NF-κB pathway.

Immune responses and central nervous system dysfunction are two main factors to be considered during rabies virus (RABV) infection. However, the mechanisms by which RABV strains of different virulence regulate with chemokine expression and the signaling pathways responsible for the immune responses in the terminal stage of infection both in vivo and in vitro have not been fully elucidated. In this study, we found low expression levels of proinflammatory chemokines in the mouse brain upon infection with street RABV strains (CXZ17 and HN10) at the late stage of infection. We also examined the difference in inflammatory response upon infection with RABV strains of different virulence in a mouse model. We found that the expression of proinflammatory chemokines increased to a varying degree upon infection with street RABV (CXZ17 and HN10) or laboratory-fixed RABV (CVS-11, aG, and CTN); CXCL10, CCL5, and CCL2 were the most significantly upregulated chemokines in brain tissue and microglial BV-2 cells in response to infection with RABV strains of different virulence. Our data also demonstrate significant activation of the MAPK and NF-κB pathways in mouse brain tissue at the late stage of RABV infection. We also found (i) low phosphorylation signals of MAPK and NF-κB p65 in neuronal cells upon infection with CXZ17 and HN10 in the mouse brain and (ii) strong phosphorylation signals in cerebrovascular endothelial cells and neuronal cells upon CTN or aG infection. Moreover, we quantified the nuclear localization status of MAPK signals and NF-κB p65 upon infection with CVS-11, aG, and CTN in BV-2 cells in vitro. We also found (i) that the activation of the p38, ERK1/2, and NF-κB p65 pathway, which stimulates CXCL10, CCL5, and CCL2 expression upon infection with RABV strains of different virulence (aG, CTN, and CVS-11), is triggered after virus entry into BV-2 cells and (ii) that the expression of CXCL10, CCL5, and CCL2 is required for the activation of NF-κB, p38, and ERK1/2, but not JNK. Overall, our study provides insight into the regulation of inflammatory responses mediated by MAPK and NF-κB in the mouse brain and in microglial cells upon RABV infection of different virulence.

Human rabies in China: evidence-based suggestions for improved case detection and data gathering.

BACKGROUND: China still suffers heavily from rabies, although reported human cases continue to decrease year over year. There are far fewer laboratory-confirmed human cases than clinically diagnosed cases, which is a big problem that needs to be addressed. In this report, we summarize analyses of all specimens from human cases tested in our laboratory over the past 15 years, in order to promote laboratory diagnosis of rabies. METHODS: From 2005 to 2019, a total of 271 samples from 164 suspected rabies cases were collected from local hospitals by the local Centers for Disease Control and Prevention (CDCs) in China. Saliva, cerebrospinal fluid (CSF), serum (blood) and urine were collected for ante-mortem diagnosis, and brain tissue, neck skin tissue and cornea were collected for post-mortem diagnosis. All of the specimens were tested by reverse transcription-polymerase chain reaction (RT-PCR), and brain tissues were also tested using fluorescent antibody test (FAT). The number of positive test results obtained using different fluids or tissues, and at different stages of the disease, were compared using a chi-square test and a more effective sampling program is recommended. RESULTS: As the national reference laboratory for rabies surveillance in China, our laboratory has tested 271 samples from 164 suspected rabies cases collected by local CDCs since 2005. We found that saliva gave the highest number of positive test results (32%), compared with CSF and other fluids. We also found that serum or blood specimens collected in the last 3 days of life can test positive by RT-PCR. CONCLUSIONS: Serum or blood samples collected in the last 3 days of a patient's life can be used to measure viral RNA, which means that serum samples, as well as saliva and CSF, can be used to detect viral RNA for anti-mortem diagnosis of rabies. Because of our findings, we have modified our "National Surveillance Project for Human Rabies", by adding the collection and testing of serum samples from the end of the survival period. This will improve our national surveillance and laboratory diagnosis of human rabies.

Effects of the nsP2-726 Pro mutation on infectivity and pathogenesis of Sindbis virus derived from a full-length infectious cDNA clone.

The point mutations at residue 726 Pro in the nonstructural gene 2 (nsP2-726P) could make Sindbis virus (SINV) replicons lacking the structural protein-coding region less cytopathic and capable of persisting in some vertebrate cell lines. However, the effects of nsP2-726P mutations on characteristics of SINV in the context of genomic-RNA are poorly understood. To investigate the effects of point mutations at nsP2-726P on the infectivity and the pathogenesis of SINV, based on the infectious clone (pBR-XJ160) of a Sindbis-like XJ-160 virus, we constructed mutants BR-726L, BR-726S, BR-726V and BR-726A containing point mutations Pro-to-Leu, Pro-to-Ser, Pro-to-Val and Pro-to-Ala. The BR-726V virus and BR-726A virus exhibited similar growth characteristics to the wild-type BR-XJ160 in cultured cells, including cytopathic effects (CPE), plaque morphology and growth kinetics. For the Leu substitution, no CPE or plaques were seen after six passages through BHK-21 cells, although expression of XJ-160 virus-specific protein was detectable by indirect immunofluorescence assay (IFA). The Ser substitutions gave an intermediate phenotype. The mutant viruses exhibited different levels of neurovirulence in 3-day-old suckling mice, which did not match their propagation in cultured cells or in the mouse brain. Compared with BR-XJ160, BR-726A with the Ala substitution showed highly increased neurovirulence, while BR-726V with the Val substitution exhibited an attenuated phenotype. In contrast, BR-726S, with reduced growth capacity in cultured cells and mouse brain, showed intermediate neurovirulence. BR-726L virus produced no lethality or morbidity in suckling mice. Thus, the nsP2-726 Pro residue regulates virus-host cell interactions directly and is also important in viral pathogenesis in suckling mice.

Selection and characterization of packaging cell lines for XJ-160 virus.

OBJECTIVES: XJ-160 virus is a mosquito-derived Sindbis-like virus isolated in China. Based on its infectious clone (pBR-XJ-160) we have developed an RNA-based vector system. In this work, we constructed packaging cell lines (PCLs) for XJ-160 virus. METHODS: Firstly, XJ-160 virus structural protein expression cassette pcE or pICH was constructed by cloning the gene of glycoprotein E3E26KE1 or capsid protein of XJ-160 virus into pcDNA3.1(+) or pIRES, respectively. Then the PCLs (BHK-21(E+Capsid) cells) for XJ-160 virus were obtained by two selections with G418 and hygromycin. RESULTS: The results indicate that BHK-21(E+Capsid) cells, stably expressing E3E26KE1 protein and capsid protein of XJ-160 virus, not only highly increased packaging efficiency of the vector from XJ-160 virus, but also provided packaging function for the vector from Semliki Forest virus. CONCLUSION: These results suggest potential utility of the PCLs of XJ-160 virus for large-scale vector production and facilitating broad alphavirus applications. Also, the construction of PCLs for XJ-160 virus lays a basis for developing alphavirus-derived vector systems.

Substitutions of 169Lys and 173Thr in nonstructural protein 1 influence the infectivity and pathogenicity of XJ-160 virus.

An infectious clone (pBR-XJ160) was constructed using the full-length cDNA of the Sindbis-like XJ-160 virus. Two nucleotide mutations, causing amino acid changes at residue 169 from Lys to Arg and at residue 173 from Thr to Ile in the nonstructural protein (nsP) 1 coding region, strongly influenced the infectivity of in vitro-synthesized RNA. We used site-directed mutagenesis to obtain clones encoding a change to Arg at residue 169 of nsP1 (pBR-169), a change to Ile at residue 173 (pBR-173), or both changes (pBR-6973). Infectivity of RNA from pBR-169 was abolished, but viral forms BR-173 and BR-6973 were obtained from pBR-173 and pBR-6973, respectively. Further, BR-173 exhibited higher propagation than BR-XJ160 in cell culture and higher neurovirulence in a suckling mouse model. BR-6973 possessed an intermediate phenotype. BR-173 and BR-6973 showed increased sensitivity to 3-deazaadenosine (3-DZA), which inhibits S-adenosylhomocysteine hydrolase. Thus, mutagenesis at residue 169 in the nsP1 region of XJ-160 is lethal, but mutation at residue 173 from Thr to Ile enhances viral infectivity and neurovirulence and suppresses the lethal effect of the mutation at residue 169. These mutations might be associated with the RNA methyltransferase (MTase) activity of nsP1.

Inner Mongolia: A Potential Portal for the Spread of Rabies to Western China.

In recent years, the number of human rabies cases in China has decreased annually. However, some western provinces with no human cases for more than 10 years have begun to report rabies cases, and all of the rabies lineages that circulated in western China were found in Inner Mongolia as well. In this study, we generated a phylogenetic tree with all the Inner Mongolia rabies strains available in GenBank and our laboratory, as well as strains from western China and representative viruses from neighboring countries, based on the N gene sequence. Furthermore, the possible relationships underlying the spread of the virus within Inner Mongolia and neighboring regions were analyzed. Three of six rabies lineages of China (China I-VI) were shown to exist in Inner Mongolia, and a spatial cluster analysis supported that the China I lineage, the dominant cluster of China, likely spread to Ningxia from Inner Mongolia. Wild raccoon dog rabies (China IV/Arctic-like-2) may have spread to Inner Mongolia from Russia and likely continued to spread to Qinghai and Tibet. The red fox lineage (China III/Cosmopolitan), which likely spread from Russia and Mongolia, has been shown to circulate in Inner Mongolia and was a serious threat to Xinjiang, which is adjacent to Inner Mongolia. Thus, Inner Mongolia likely became a location where national and international rabies viruses collected and developed into a potential portal for the spread of rabies to western China. To effectively control the spread of rabies in China, both prevention and control of dog and wild animal rabies in Inner Mongolia should be a top priority.

The reemergence of human rabies and emergence of an Indian subcontinent lineage in Tibet, China.

Coordinated surveillance, vaccination and public information efforts have brought the Chinese rabies epizootic under control, but significant numbers of fatalities are still reported annually with some cases occurring in previously rabies free regions. Tibet has remained virtually rabies free for 16 years, but since 2015 one human rabies case has been reported each year. To better understand the origins of these cases, we sequenced three human samples and an additional sample isolated from a dog in 2012. Three genomes were sequenced from brain samples: human case 1 (reported in 2015), human case 3 (2017), and the 2012 dog case. For human case 2 (2016), the rabies N gene was sequenced from a limited saliva sample. Phylogenetic analysis shows that Case 1 (CXZ1501H) and the dog case (CXZ1201D) belong to China IV lineage (equivalent to Arctic-like-2 in global rabies), suggesting an association with a wildlife spillover event. However, Case 2 (CXZ1601H) is placed within the dominant lineage China I, and was most similar with recent strains from neighboring Yunnan province, indicating the current epizootic has finally reached Tibet. Most surprisingly however, was the finding that Case 3 (CXZ1704H) is distinct from other Chinese isolates. This isolate is placed in the Indian Subcontinent clade, similar to recent Nepal strains, indicating that cross-border transmission is a new source for rabies infections. Thus, the complex mixture of the rabies epizootic in Tibet represents a major new challenge for Tibet and national rabies control.

Rabies virus transmission via solid organs or tissue allotransplantation.

BACKGROUND: Rabies, for which the mortality rate is almost 100%, is a zoonotic viral disease that can be transmitted via solid organs or tissue allotransplantation. Dozens of deaths from rabies via solid organs or tissues allotransplantation (ROTA) have been documented during the last decades. In 2015 and 2016, two cases of rabies virus transmission via solid organs or tissue allotransplantation were reported in China, which further underscore the risk and importance of this special type of rabies for organ transplant recipients. MAIN TEXT: From 1978 to 2017, at least 13 cases of ROTA, causing dozens of deaths, have been reported worldwide, whether in the high-risk or low-risk countries of rabies. The reported incubation period of ROTA ranges from 11 days to more than 17 months, while the historical incubation period of rabies is generally considered to range from ~ 1 week to several years. The pathogenesis of ROTA is not clear, but the use of post-exposure prophylaxis (PEP) can play a protective role in the transplant recipients. We also summarize reports about ROTA in China, combined with the actual situation regarding work on rabies surveillance and elimination, and suggest countermeasures for the prevention and control of ROTA in the future. CONCLUSIONS: Understanding the significance of ROTA, screening the suspected organs, assessing the risk and protecting the related population will be effective way to prevent and control further occurrence of ROTA.

Conjugated polymer nanoparticles-based fluorescent biosensor for ultrasensitive detection of hydroquinone.

This work describes a simple and sensitive fluorescent method for detection of hydroquinone utilizing conjugated polymer nanoparticles (CPNs). The CPNs serve both as a catalyst to accelerate the conversion of hydroquinone to benzoquinone and a fluorescent probe. In the presence of hydroquinone, the fluorescence of CPNs can be effectively quenched by benzoquinone. The detection limit of hydroquinone was down to 5 nM and excellent selectivity toward possible interferences was obtained. This method was successfully applied for hydroquinone detection in lake water and satisfactory results were achieved.