Molecular identification and characterization of two proposed new enterovirus serotypes, EV74 and EV75

Fil: Oberste, M. Steven. Centers for Disease Control and Prevention. Respiratory and Enteric Viruses Branch; Estados Unidos.Fil: Michele, Suzanne M. Centers for Disease Control and Prevention. Respiratory and Enteric Viruses Branch; Estados Unidos.Fil: Maher, Kaija. Centers for Disease Control and Prevention. Respiratory and Enteric Viruses Branch; Estados Unidos.Fil: Schnurr, David. California Department of Health Services. Viral and Rickettsial Disease Laboratory; Estados Unidos.Fil: Cisterna, Daniel. ANLIS Dr.C.G.Malbrán. Instituto Nacional de Enfermedades Infecciosas; Argentina.Fil: Junttila, Nina. Swedish Institute for Disease Control. Department of Virology; Suecia.Fil: Uddin, Moyez. Institute of Public Health; Bangladesh.Fil: Chomel, Jean-Jacques. Centre National de Référence des Entérovirus; Francia.Fil: Lau, Chi-Shan. Queen Mary Hospital. Department of Health; China.Fil: Ridha, Walid. National Polio Laboratory; Irak.Fil: Al-Busaidy, Suleiman. Ministry of Health. Department of Laboratories; Oman.Fil: Norder, Helene. Swedish Institute for Disease Control. Department of Virology; Suecia.Fil: Magnius, Lars O. Swedish Institute for Disease Control. Department of Virology; Suecia.Fil: Pallansch, Mark A. Centers for Disease Control and Prevention. Respiratory and Enteric Viruses Branch; Estados Unidos.Sequencing of the gene that encodes the capsid protein VP1 has been used as a surrogate for antigenic typing in order to distinguish enterovirus serotypes; three new serotypes were identified recently by this method. In this study, 14 enterovirus isolates from six countries were characterized as members of two new types within the species Human enterovirus B, based on sequencing of the complete capsid-encoding (P1) region. Isolates within each of these two types differed significantly from one another and from all other known enterovirus serotypes on the basis of sequences that encode either VP1 alone or the entire P1 region. Members of each type were greater than or equal to 77(.)2% identical to one another (89(.)5% amino acid identity) in VP1, but members of the two different types differed from one another and from other enteroviruses by greater than or equal to 31% in nucleotide sequence (25% amino acid sequence difference), indicating that the two groups represent separate new candidate enterovirus types. The complete P1 sequences differed from those of all other enterovirus serotypes by greater than or equal to 31% (26% amino acid sequence difference), but were highly conserved within a serotype (< 8% amino acid sequence difference). Phylogenetic analyses demonstrated that isolates of the same serotype were monophyletic in both VP1 and the capsid as a whole, as shown previously for other enterovirus serotypes. This paper proposes that these 14 isolates should be classified as members of two new human enterovirus types, enteroviruses 74 and 75 (EV74 and EV75)

Peculiarities in the designations of hepatitis B virus genes, their products, and their antigenic specificities: a potential source of misunderstandings

The nomenclature of the hepatitis B virus (HBV) genes and their products has developed stepwise, occasionally in an erratic way, creating many misunderstandings, especially among those who do not know the structure of HBV and its genome in detail. One of the most frequent misunderstandings, even presented in leading journals, is the designation of HBV 'e'-antigen as envelope or early antigen. Another problem area are the so-called 'pre' regions in the HBV genome present upstream of both the core and the surface genes of HBV, inadvertently suggesting that they may be a part of corresponding precursor proteins. Misnomers and misclassifications are frequent in defining the subgenotypes and serological subtypes of HBV. Even the well-established terminology for HBV surface (HBs) or HBV core (HBc) antigen deviates from the conventional virological nomenclature for viral envelopes or capsid proteins/antigens, respectively. Another matter of undesirable variability between publications is the numbering of the nucleotides and the graphical representation of genomic maps. This editorial briefly explains how the nomenclature evolved, what it really means, and suggests how it could be adapted to today's knowledge

A Natural Intergenotypic Recombinant of Hepatitis C Virus Identified in St. Petersburg

Hepatitis C virus (HCV) evolution is thought to proceed by mutations within the six genotypes. Here, we report on a viable spontaneous HCV recombinant and we show that recombination may play a role in the evolution of this virus. Previously, 149 HCV strains from St. Petersburg had been subtyped by limited sequencing within the NS5B region. In the present study, the core regions of 41 of these strains were sequenced to investigate the concordance of HCV genotyping for these two genomic regions. Two phylogenetically related HCV strains were found to belong to different subtypes, 2k and 1b, according to sequence analysis of the 5′ untranslated region (5′UTR)-core and the NS5B regions, respectively. By sequencing of the E2-p7-NS2 region, the crossover point was mapped within the NS2 region, probably between positions 3175 and 3176 (according to the numbering system for strain pj6CF). Sequencing of the 5′UTR-core regions of four other HCV strains, phylogenetically related to the above-mentioned two strains (based on analysis within the NS5B region), revealed that these four strains were also recombinants. Since a nonrecombinant 2k strain was found in St. Petersburg, the recombination may have taken place there around a decade ago. Since the frequency of this recombinant is now high enough to allow the detection of the recombinant in a fraction of the city's population, it seems to be actively spreading there. The reported recombinant is tentatively designated RF1_2k/1b, in agreement with the nomenclature used for HIV recombinants. Recombination between HCV genotypes must now be considered in the classification, laboratory diagnosis, and treatment of HCV infection

Antigenic diversity of hepatitis B virus strains of genotype F in Amerindians and other population groups from Venezuela

The adw4 subtype of hepatitis B virus (HBV) belongs to a unique genomic group (genotype F) representing the original HBV strains from the New World. Data regarding the prevalence of this subtype among HBV carriers in South America are, however, scarce, and those concerning HBV genotype F are based on only a few samples from Latin America. In this study, serum samples were obtained from 141 hepatitis B surface antigen (HBsAg) carriers from Amerindians and urban populations from Venezuela. The HBsAg subtype was identified with monoclonal antibodies in 105 samples, and the HBV genotype was identified by reverse-phase hybridization with DNA fragments in 58 samples. The adw4 subtype was highly prevalent in the population studied (75%); among the Amerindians, the prevalence was 97%. The adw2 subtype was also present (10%), while other subtypes (ayw3 and ayw4) were only occasionally found. The HBV subtype was associated with the expected genotype in most cases (80%), and thus genotype F was highly prevalent. Sequencing of viral strains that gave genotypes unpredicted by the HBsAg subtyping confirmed seven of them as belonging to not previously described genotype-subtype associations: namely, adw2 and ayw4 within genotype F