In a molecular epidemiology study of hepatitis E virus (HEV) in dromedaries in Dubai, United Arab Emirates, HEV was detected in fecal samples from 3 camels. Complete genome sequencing of 2 strains ...showed >20% overall nucleotide difference to known HEVs. Comparative genomic and phylogenetic analyses revealed a previously unrecognized HEV genotype.
All hepatitis E virus (HEV) variants reported to infect humans belong to the species Orthohepevirus A (HEV-A). The zoonotic potential of the species Orthohepevirus C (HEV-C), which circulates in rats ...and is highly divergent from HEV-A, is unknown. We report a liver transplant recipient with hepatitis caused by HEV-C infection. We detected HEV-C RNA in multiple clinical samples and HEV-C antigen in the liver. The complete genome of the HEV-C isolate had 93.7% nt similarity to an HEV-C strain from Vietnam. The patient had preexisting HEV antibodies, which were not protective against HEV-C infection. Ribavirin was an effective treatment, resulting in resolution of hepatitis and clearance of HEV-C viremia. Testing for this zoonotic virus should be performed for immunocompromised and immunocompetent patients with unexplained hepatitis because routine hepatitis E diagnostic tests may miss HEV-C infection. HEV-C is also a potential threat to the blood product supply.
Antibacterial resistance to infectious diseases is a significant global concern for health care organizations; along with aging populations and increasing cancer rates, it represents a great burden ...for government healthcare systems. Therefore, the development of therapies against bacterial infection and cancer is an important strategy for healthcare research. Pathogenic bacteria and cancer have developed a broad range of sophisticated strategies to survive or propagate inside a host and cause infection or spread disease. Bacteria can employ their own metabolism pathways to obtain nutrients from the host cells in order to survive. Similarly, cancer cells can dysregulate normal human cell metabolic pathways so that they can grow and spread. One common feature of the adaption and disruption of metabolic pathways observed in bacterial and cancer cell growth is amino acid pathways; these have recently been targeted as a novel approach to manage bacterial infections and cancer therapy. In particular, arginine metabolism has been illustrated to be important not only for bacterial pathogenesis but also for cancer therapy. Therefore, greater insights into arginine metabolism of pathogenic bacteria and cancer cells would provide possible targets for controlling of bacterial infection and cancer treatment. This review will summarize the recent progress on the relationship of arginine metabolism with bacterial pathogenesis and cancer therapy, with a particular focus on arginase and arginine deiminase pathways of arginine catabolism.
Hepatitis E virus (HEV) is zoonotic and a major cause of acute viral hepatitis worldwide. Recently, we identified a novel HEV genotype 8 (HEV8) in Bactrian camels in Xinjiang, China. However, the ...epidemiology, pathogenicity, and zoonotic potential of HEV8 are unclear. Here, we present the prevalence of HEV8 in China and investigate its pathogenicity and cross-species transmission in cynomolgus macaques. Fresh fecal and milk samples from Bactrian camels collected from four provinces/regions in China were screened for HEV RNA by reverse transcriptase PCR (RT-PCR). An HEV8-positive sample was used to inoculate two cynomolgus macaques to examine the potential for cross-species infection. The pathogenicity of HEV8 was analyzed by testing HEV markers and liver function during the study period and histopathology of liver biopsy specimens at 3, 13, and 25 weeks postinoculation. Extrahepatic replication was tested by using reverse transcriptase quantitative PCR (RT-qPCR) and immunofluorescence assays. The overall prevalence of HEV8 RNA in Chinese Bactrian camels was 1.4% (4/295), and positive samples were found in three different provinces/regions in China. Histopathology confirmed acute and chronic HEV8 infections in the two monkeys. Multiple tissues were positive for HEV RNA and ORF2 proteins. Renal pathology was observed in the monkey with chronic hepatitis. Whole-genome sequencing showed only 1 to 3 mutations in the HEV8 in the fecal samples from the two monkeys compared to that from the camel. HEV8 is circulating in multiple regions in China. Infection of two monkeys with HEV8 induced chronic and systemic infections, demonstrating the high potential zoonotic risk of HEV8.
It is estimated that one-third of the world population have been exposed to hepatitis E virus (HEV). In developed countries and China, zoonotic HEV strains are responsible for almost all acute and chronic HEV infection cases. It is always of immediate interest to investigate the zoonotic potential of novel HEV strains. In 2016, we discovered a novel HEV genotype, HEV8, in Bactrian camels, but the epidemiology, zoonotic potential, and pathogenicity of the virus were unknown. In the present study, we demonstrated that HEV8 was circulating in multiple regions in China and was capable of infecting cynomolgus macaques, a surrogate for humans, posing high risk of zoonosis. Chronic hepatitis, systemic infection, and renal pathology were observed. Collectively, these data indicate that HEV8 exhibits a high potential for zoonotic transmission. Considering the importance of Bactrian camels as livestock animals, risk groups, such as camelid meat and milk consumers, should be screened for HEV8 infection.
Abstract The recent discovery of Middle East Respiratory Coronavirus and another novel dromedary camel coronavirus UAE-HKU23 in dromedaries has boosted interest in search of novel viruses in ...dromedaries. In this study, fecal samples of 203 dromedaries in Dubai were pooled and deep sequenced. Among the 7330 assembled viral contigs, 1970 were assigned to mammalian viruses. The largest groups of these contigs matched to Picobirnaviridae , Circoviridae , Picornaviridae , Parvoviridae, Astroviridae and Hepeviridae . Many of these viral families were previously unknown to dromedaries. In addition to the high abundance of contigs from Circoviridae ( n =598 with 14 complete genomes) and Picobirnaviridae ( n =1236), a high diversity of contigs from these two families was found, with the 14 Circoviridae complete genomes forming at least five clusters and contigs from both genogroup I and genogroup II potentially novel picobirnaviruses. Further studies comparing the incidence of these viral families in healthy and sick dromedaries will reveal their pathogenic potential.
Hepatitis E virus (HEV) is a major cause of viral hepatitis globally. Zoonotic HEV is an important cause of chronic hepatitis in immunocompromised patients. The rapid identification of novel HEV ...variants and accumulating sequence information has prompted significant changes in taxonomy of the family Hepeviridae. This family includes two genera:
, which infects terrestrial vertebrates, and
, which infects fish. Within
, there are four species, A-D, with widely differing host range.
A contains the HEV variants infecting humans and its significance continues to expand with new clinical information. We now recognize eight genotypes within
A: HEV1 and HEV2, restricted to humans; HEV3, which circulates among humans, swine, rabbits, deer and mongooses; HEV4, which circulates between humans and swine; HEV5 and HEV6, which are found in wild boars; and HEV7 and HEV8, which were recently identified in dromedary and Bactrian camels, respectively. HEV7 is an example of a novel genotype that was found to have significance to human health shortly after discovery. In this review, we summarize recent developments in HEV molecular taxonomy, epidemiology and evolution and describe the discovery of novel camel HEV genotypes as an illustrative example of the changes in this field.
We report the identification and genome characterization of a novel bocavirus, feline bocavirus (FBoV), and novel bocaviruses closely related to canine bocavirus (CBoV) strain Con-161 in stray cats ...and dogs in Hong Kong, respectively. FBoV was detected by PCR in 7.2, 0.3, 1.6, 2.0 and 0.8% of faecal, nasal, urine, kidney and blood samples, respectively, from 364 cats, while CBoV was detected in 4.6, 5.1, 6.3 and 0.3% of faecal, nasal, urine and blood samples, respectively, from 351 dogs. Three FBoV genomes sequenced revealed the presence of three ORFs characteristic of bocaviruses. Phylogenetic analysis showed that FBoVs were related only distantly to other bocaviruses, forming a distinct cluster within the genus, with ≤ 5.7% nucleotide identities to the genome of minute virus of canines. The four CBoV genomes sequenced shared 87.4-89.2% nucleotide identities with that of CBoV strain Con-161. In addition to the three bocavirus ORFs, they encoded an additional ORF, ORF4, immediately downstream of the ORF for non-structural protein 1 (NS1), which was not found in other bocaviruses including CBoV strain Con-161. They also possessed a putative second exon encoding the C-terminal region of NS1 and conserved RNA-splicing signals, previously described in human bocaviruses. Partial VP1/VP2 sequence analysis of 23 FBoV and 25 CBoV strains demonstrated inter-host genetic diversity, with two potential genetic groups of FBoV and a novel CBoV group, CBoV-HK, distinct from the three groups, CBoV-A to -C, found in the USA. Although the pathogenicity of FBoV and CBoV remains to be determined, their presence in different host tissues suggested wide tissue tropism.
Abstract
Compared with other countries, a more substantial decrease in the incidence of invasive pneumococcal disease was observed in Hong Kong, which is most likely attributable to the proactive ...mass adoption of face masks by the public. Human behavioral changes, particularly mask wearing, should be considered as an additional preventive strategy against invasive pneumococcal disease.
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