B2 Sequences Research Articles

Molecular characterization of the Tobacco rattle virus RNA2 genome isolated from Gladiolus.

Tobacco rattle virus (TRV-K) was first identified in a symptomatic Gladiolus plant cultivated in Korea. We analyzed the TRV-K genome and compared its phylogeny with other TRV isolates. After constructing of a full-length genomic RNA2 strand clone, a complete sequence was generated from several overlapping clones. The cloned genome was 3261 bases in length, identical to TRV-K, and had three open reading frames. TRV-K had the highest sequence identity with the American isolate TRV-ORY. Sequence analysis of the RNA2 genome showed that TRV-K contains an intact 2a, 2b, and 2c coding sequence and an RNA1-related 3' terminus, which is typical of TRV RNA2. Phylogenetic analysis revealed that TRV-K is in the same cluster as the American isolates and another Korean isolate, TRV-SK; however, it was in a different cluster than the European isolates.

Worldwide distribution of the NS3 gene 80K polymorphism among circulating hepatitis C genotype 1 viruses: implication for simeprevir usage.

Several direct-acting agents against the hepatitis C virus (HCV) NS3 protease and NS5b polymerase have been developed in recent years to improve treatment of this viral infection. Of these, simeprevir is currently recommended for HCV genotype 1 and 4 infections, but genotypic assessment for the presence of 80K is required prior to simeprevir administration due to the reduced susceptibility of genotype 1 viruses carrying that polymorphism. Because the prevalence of 80K at baseline in genotype 1 viruses varies between reports, we wanted to assess its worldwide prevalence. Over 3000 HCV genotype 1 sequences reported from drug-naive subjects distributed around the world were retrieved from the HCV Los Alamos and GenBank databases. These were categorized into subtypes and geographical provenance (continent and country), and the presence of the 80K and 80R polymorphisms was visually inspected and counted. Disparate prevalence of 80K was observed depending on the country/continent analysed. While in resource-rich areas (USA, Western Europe and Australia) a high prevalence of 80K was seen in HCV subtype 1a, in emerging countries, such as Brazil, this prevalence was very low(<1%). HCV subtype 1b sequences from France also displayed a significant occurrence of 80K (6.1%). 80R, on the other hand, was negligible worldwide. The genotypic assessment of 80K in HCV subtype 1a prior to simeprevir administration in emerging countries with significant numbers of HCV infection is questionable, while it should be performed for subtype 1b in certain developed countries.

Complete genome sequence of emerging porcine circovirus types 2a and 2b from India.

We report here the first characterized complete genome sequence of porcine circovirus types 2a and 2b from northeastern states of India. These isolates may serve as a potential reference for the Indian strains of porcine circovirus types 2a and 2b.

Mutations of the human interferon alpha-2b (hIFN-α2b) gene in occupationally protracted low dose radiation exposed personnel

Ionizing radiations impact human tissues by affecting the DNA bases which constitute genes. Human interferon alpha 2b gene synthesizes a protein which is an important anticancerous, immunomodulatory, anti-proliferative and antiviral protein. This study was aimed to identify interferon alpha-2b mutations as a consequence of the use of occupational chronic low dose radiation by hospital radiation exposed workers. A molecular analysis was done in which DNAs were extracted from blood samples from radiology, radiotherapy and nuclear medicine workers. The gene was amplified through polymerase chain reaction and further genetic data from sequencing results analyzed by bioinformatics tools in order to determine as to how mutations in interferon alpha 2b sequences will lead to changes in human interferon alpha-2b protein. A total of 41% gene mutations was detected among all radiation exposed workers in which higher percentage (5.4%) of base insertion mutations and 14% frameshift mutations were found in radiology workers. The chronic use of low dose of radiations by occupational workers has a significant correlation with mutational effects on interferon alpha 2b gene, further evident by depressed interferon alpha levels in serum. This can lead to depressed immunity in radiation exposed workers. Hematological profiling of this group also showed hyperimmune response in the form of lymphocytosis.

RNAe: an effective method for targeted protein translation enhancement by artificial non-coding RNA with SINEB2 repeat.

In this study, a universal protein expression enhancement RNA tool, termed RNAe, was developed by modifying a recently discovered natural long non-coding RNA. At the moment, RNAe is the only technology for gene expression enhancement, as opposed to silencing, at the post-transcriptional level. With this technology, an expression enhancement of 50–1000% is achievable, with more than 200% enhancement achieved in most cases. This work identified the sufficient and necessary element for RNAe function, which was found to be merely 300 nucleotides long and was named minRNAe. It contains a 72-nt 5' pairing sequence which determines the specificity, a 167-nt short non-pairing interspersed nuclear element (SINE) B2 sequence which enhances ribosome recruitment to the target mRNA, and a poly(A) tail, provided together on a plasmid bearing the appropriate sequences. Cellular delivery of RNAe was achieved using routine transfection. The RNAe platform was validated in several widely-used mammalian cell lines. It was proven to be efficient and flexible in specifically enhancing the expression of various endogenous and exogenous proteins of diverse functions in a dose-dependent manner. Compared to the expression-inhibitory tool RNAi, the RNAe tool has a comparable effect size, with an enhancing as opposed to inhibitory effect. One may predict that this brand new technology for enhancing the production of proteins will find wide applications in both research and biopharmaceutical production.

Orthogonal Encoding for High-bit Golay Excitation in Dual-Frequency Harmonic Imaging

Dual-frequency (DF) harmonic imaging simultaneously utilizes the imaging information at both f0and 2f0 frequencies. When phase-coded complementary Golay sequence is combined with DF harmonic imaging to improve signal-to-noise ratio, however, the mutual crosstalk between the f0and 2f0 imaging bands may degrade the image quality. In this study, orthogonal encoding is proposed to suppress the crosstalk artifacts byencoding the f0 and 2f0imaging signals as a1(n) and a2(n) sequence in the first firing and b1(n) and b2(n) sequence in the second firing. The a1(n), b1(n) is one complementary Golay pair and the a2(n), b2(n) is another complementary Golay pair. The two complementary pairs are orthogonal to each other. Both hydrophone measurement and B-mode imaging show that the orthogonal encoding effectively suppresses the mutual crosstalk and restore the resultant main lobe width after Golay decoding.

Dense infinite $B_h$ sequences

For h = 3 and h = 4 we prove the existence of infinite Bh sequences B with counting function B(x) = x√(h−1)2+1−(h−1)+o(1). This result extends a construction of I. Ruzsa for B2 sequences.

Generation and Characterisation of HCV Genotype 1 Viruses Most Recent Common Ancestor

Background: Hepatitis C virus (HCV) causes acute and chronic liver diseases in humans. Its two envelope glycoproteins, E1 and E2, interact with host cell receptors and provide a target for neutralising antibodies. Past vaccine studies using unmodified E2 proteins have failed to convincingly generate broadly neutralising antibody responses. Objectives: This study sought to generate and evaluate an immune-focused, vaccine candidate for HCV. Methodology: A synthetic construct based on most recent common ancestral sequence (MRCA) of HCV genotype 1 viruses was generated using sequences available from the Los Alamos HCV database [720 sequences (360 subtype 1a and 360 subtype 1b sequences)], after exclusion of epidemiologically-related sequences. Soluble E2 (sE2) proteins were generated by stably transfected S2 cells and purified using Strep- tag purification and size exclusion chromatography. The MRCA construct was subsequently interrogated using a linear (AP33) and conformational (1:7) monoclonal antibodies directed at E2. A full length E1E2 construct was used for production of HCV pseudoparticles (HCVpp). The infectivity of the HCVpp was measured in the presence of monoclonal antibodies; AP33 1:7 and AR3A. Results: Monomeric proteins of the MRCA generated using a Drosophila expression system were conformationally intact when examined by the monoclonal antibody 1:7 that targets the conformational epitope on E2 responsible for interaction with the CD81 receptors. The full length MRCA E1E2 construct showed functionality in the HCV pseudo-particle (HCVpp) system. The MRCA HCVpp construct was susceptible to neutralisation by AP33, 1:7 and AR3A, in dose- dependant manner. Conclusion: This study demonstrates the generation of a functional construct that could be used as a vaccine candidate in a potential vaccine approach to minimise the problem of genetic diversity between the vaccine construct and contemporary viruses.

Spectrum of Type 2 Von Willebrand Disease in the Zimmerman Program

▪While von Willebrand disease (VWD) is the most common inherited bleeding disorder, most patients have quantitative defects in von Willebrand factor (VWF). The qualitative variants, collectively termed type 2 VWD, are less common, but also in general more severe than type 1 VWD. However, despite a common laboratory phenotype of decreased VWF:RCo/VWF:Ag ratio for types 2A, 2B, and 2M VWD, the clinical phenotype is highly variable. We examined index cases and affected family members enrolled in the Zimmerman Program with a phenotypic diagnosis of type 2 VWD. All subjects had factor VIII (FVIII), VWF antigen (VWF:Ag), VWF ristocetin cofactor activity (VWF:RCo), and multimer distribution analyzed in a central laboratory. For calculation of mean VWF:RCo values, a level of 5 was assigned to subjects with VWF:RCo below the laboratory lower limit of detection of 10 IU/dL. A platelet binding assay was also performed using a gain of function GPIb containing 2 mutations that enable spontaneous binding to VWF in the absence of ristocetin (VWF:GPIbM). Full length VWF gene sequencing was performed for all index cases. Targeted sequencing was performed for family members to ascertain the presence or absence of sequence variations found in the index case. Bleeding symptoms were quantified using the ISTH bleeding assessment tool and reported as bleeding scores (BS). Mean FVIII, VWF:Ag, VWF:RCo, and BS are listed in the table below for each type 2 variant.For type 2A VWD, 113 subjects have been enrolled to date. All had an abnormal multimer distribution with loss of high molecular weight multimers. 6 type 2A subjects had a VWF:RCo/VWF:Ag ratio of ≤0.7. The lowest VWF:RCo levels were seen in the type 2A cohort with 60% <10. 98% of type 2A subjects had an identified sequence variation on full length sequencing. 25% had the p.R1597W sequence variation and an additional 4 subjects had p.R1597Q. The mean bleeding score for the subjects with sequence variations at 1597 was 10.6. 11% of subjects had p.R1374H, which correlated with a higher mean bleeding score of 12.4. Mean bleeding score for the remainder of the type 2A subjects was lower, at 6.6, suggesting that differences in VWF genetics may account for differences in phenotype, despite the common type 2A laboratory presentation of reduced VWF:RCo and loss of high molecular weight multimers.44 type 2B subjects have been enrolled to date, all with abnormal multimer distribution and either documented abnormal VWF-platelet binding or a presence of a known type 2B sequence variation. Sequence variations were found in 100% of subjects. The most common sequence variations were p.V1316M (20%), p.R1306W (18%), p.R1341Q (11%), and p.H1268Y (9%). Mean VWF:RCo/VWF:Ag ratios ranged from 0.32-1.12, suggesting that a normal VWF:RCo/VWF:Ag ratio cannot completely exclude the possibility of type 2B VWD. Most (94%) had increased VWF:GPIbM. Subjects with p.V1316M and p.R1306W/Q sequence variations had lower VWF:RCo compared to subjects with p.R1341Q/W but mean bleeding scores did not differ.59 type 2M subjects have been enrolled to date. Mean VWF:RCo/VWF:Ag ratio was 0.46 (range 0.14-0.7). Sequence variations were found in 93% of subjects. R1374C was found in 13 members from one family. While mean VWF levels were similar to the entire 2M group, a wide range in VWF:Ag and VWF:RCo/VWF:Ag ratio was observed, accompanied by a corresponding range in BS from 0-8. This suggests that other modifiers of phenotype may be present aside from the VWF sequence variation.11 type 2N subjects have been enrolled to date, all with low VWF binding to FVIII. Sequence variations were found in 100% of this cohort. R854Q was present in 89% of subjects. Bleeding scores were highest for homozygous 2N sequence variations.Overall, the mean BS for type 1 VWD subjects was 6.3, the mean BS for type 2 VWD subjects was 7.5, and the mean BS for type 3 VWD subjects was 16.8. Types 2A and 2N had higher bleeding scores on average than type 2B, and type 2M subjects had on average the lowest bleeding scores. Although heterogeneity was seen across all the type 2 variants, both laboratory testing and genetic testing are useful in categorizing and phenotyping type 2 VWD.TableFVIII (mean)VWF:Ag (mean)VWF:RCo (mean)BS (mean)Type 2A4734128.7Type 2B4536237.1Type 2M6254215.4Type 2N3069768.3 DisclosuresMontgomery:Immucor: Patents & Royalties.

Complete Genome Sequence of Coxsackievirus B1 Isolated during Case Outbreaks in 2007 in the United States.

In 2007, clusters of severe coxsackievirus B1 (CVB1) infection occurred across the United States, and CVB1 became the most commonly reported enterovirus. The complete genome sequence of CVB1 isolated from an infant (CVB1-Chi07) was examined and found to be divergent from the Conn5 reference strain, with 80% and 96% similarities at the nucleotide and amino acid levels, respectively.

Promoter-specific alterations of APC are a rare cause for mutation-negative familial adenomatous polyposis.

n familial adenomatous polyposis (FAP), 20% of classical and 70% of attenuated/atypical (AFAP) cases remain mutation-negative after routine testing; yet, allelic expression imbalance may suggest an APC alteration. Our aim was to determine the proportion of families attributable to genetic or epigenetic changes in the APC promoter region. We studied 51 unrelated families/cases (26 with classical FAP and 25 with AFAP) with no point mutations in the exons and exon/intron borders and no rearrangements by multiplex ligation-dependent probe amplification (MLPA, P043-B1). Promoter-specific events of APC were addressed by targeted resequencing, MLPA (P043-C1), methylation-specific MLPA, and Sanger sequencing of promoter regions. A novel 132-kb deletion encompassing the APC promoter 1B and upstream sequence occurred in a classical FAP family with allele-specific APC expression. No promoter-specific point mutations or hypermethylation were present in any family. In conclusion, promoter-specific alterations are a rare cause for mutation-negative FAP (1/51, 2%). The frequency and clinical correlations of promoter 1B deletions are poorly defined. This investigation provides frequencies of 1/26 (4%) for classical FAP, 0/25 (0%) for AFAP, and 1/7 (14%) for families with allele-specific expression of APC. Clinically, promoter 1B deletions may associate with classical FAP without extracolonic manifestations.

Genome Sequence of a Promising Hydrogen-Producing Facultative Anaerobic Bacterium, Brevundimonas naejangsanensis Strain B1.

Brevundimonas naejangsanensis strain B1 is a newly isolated, facultative anaerobic bacterium capable of producing hydrogen with high efficiency. Here, we present a 2.94-Mb assembly of the genome sequence of strain B1, which may provide further insights into the molecular mechanism of hydrogen production from bioresource.

Development of Dot-blot Hybridization Based on 522 bp Repetitive Sequence (R522) for Detection of Toxoplasma gondii

Toxoplasmosis, arising from infection by Toxoplasma gondii, is one of the most common parasitic diseases in humans and other warm-blooded animals. In humans, infections are usually asymptomatic but severe disease can occur in immunocompromized individuals and newborns. Due to the importance of the disease and in order to take suitable measures, an early diagnosis of the disease is essential, particularly for pregnant women and in industry of domestic animals. The genome of T. gondii contains repeat sequences B1 and R522 which constitute ideal targets for genome-based detection methods. The 522 base pairs repeat sequences R522 are the most promising due to the high copy number, evaluated to be 200 to 300 units within the genome. We developed a simple dot-blot hybridization based on R522 sequences. The method is simple and does not require sophisticated devices. The test of the method, using cloned R522 as target, showed that the parasite detection method was sensitive and proved to be promising for use in routine health controls as well as for the survey of Toxoplasma infections. Key words: DIG-probe, dot blot hybridization, repeat sequences, R522, Toxoplasma gondii

The Jurassic–Cretaceous volcanism of the Atlas of Beni-Mellal (Central High Atlas, Morocco): evidence from clinopyroxene composition

The Central High Atlas volcanism (CHAV) extruded the synclinal basins of the Central High Atlas and shows entablature shapes constituted by basaltic lavas as two volcanic sequences B1 and B2, which correspond to distinct volcanic events. The original flows fissure bet up to the open air, or under very shallow water. Basaltic rocks consist of olivine basalt. Clinopyroxene compositions range from augite in B1 to diopside in B2 basaltic sequences. The clinopyroxene Ti content is low and typically does not exceed 1 %. In diagrams of clinopyroxene composition based on discriminant functions, the clinopyroxene geochemical data of CHAV show the transitional nature of B1, while this character decreases in B2. They plot in the within-plate basalt field. The study of both B1 and B2 basalts shows that these two basaltic sequences were derived from a common magma. Whole rock analyses prove the results. CHAV is a part of the geodynamic evolution of the Atlas domain, which is ruled by two major events: the opening of the Central Atlantic and the Mediterranean convergence.

LINE class retroposon is a component of DNA polymorphic fragments of trematode Himasthla elongata parthenitae

We found that the S-SAP (Sequence-Specific Amplification Polymorphism) method revealed clonal variability in the genomes of flatworm Himasthla elongata (Trematoda, Echinostomatidae) larvae. The larvae are parthenogenetic and have been considered genetically homogeneous. We performed cloning and sequencing of an about 500-bp conservative fragment (B1). B1 sequence analysis showed that this fragment had maximal homology with LINE elements from the CR1 family of Hydra and sparrow. In situ hybridization (FISH) revealed B1 dispersed distribution. Several other fragments cloned from the same agarose electrophoresis band correspond to the conservative domain of reverse transcriptase (RT) from CR1 family. Thus, it has been shown that (1) cercariae of trematode H. elongata have clonal variability, (2) the S-SAP method allows patterns to be obtained of fragment distribution characteristic for individual cercariae, and (3) RT conservative domain of the CR1 family participates in the pattern of polymorphic fragments generation. Identification of the CR1 transcripts in H. elongata cercariae transcriptom will be the aim of a future work. Cloning of variable fragments from the pattern of fragments is in progress.

Les Basaltes de l’Atlas de Béni-Mellal (Haut Atlas Central, Maroc): un Volcanisme Transitionnel Intraplaque Associé aux Stades de L’évolution Géodynamique du Domaine Atlasique

The basaltic rocks emitted at the synclinal basins of the Atlas of Beni-Mellal, show entablatures shapes constituted by interbedded lava flow successions with red silted-sandstone layers (Red Beds). In the synclinal basins of the area, basaltic lavas form two volcanic sequences B1 and B2 which correspond to distinct volcanic events. Pyroclastic deposits are rare. Basaltic outcrops show no pillow lavas. The lava flows were emplaced while the sediments were still soft and unconsolidated. The original flows fissure bet up to the open air, or under very shallow water. Ages of basaltic flows grouped around two distinct values t hat correspond to the Middle Jurassic (B1 basalts) and to the last of the Lower Cretaceous (B2 basalts). Basaltic rocks consist of olivine basalt. Textures are variable and dependent of the type of structure. Lavas flows typically show porphyritic texture at the bottom of entablatures, fluidal structure in its inner parts and vesicules at its upper zone. Clinopyroxene compositions range from augite in B1 to diopside in B2 basaltic horizons. Whole rock compositions mark the transitional character of these volcanic rocks. Normative composition show low nepheline contents (≤ 5%). LREE/HREE ratios are low and clearly less enriched than those obtained for alkaline magmatic series. Spidergram spectra are similar to those of Oceanic Island basalts (OIB). The relative geochemical dissimilitude reported at the both basaltic sequences B1 and B2, indicate, eventually, the changing of the magmatic regime, which becomes from tholeiitic to purely alkaline in Cenozoic, in relation to the geodynamic evolution of atlasic domain. This geodynamic and geochemical evolution is ruled by two major events: the opening of the Central Atlantic and the Mediterranean convergence.

Neutralization resistance of hepatitis C virus can be overcome by recombinant human monoclonal antibodies

Immunotherapy and vaccine development for hepatitis C virus (HCV) will depend on broadly reactive neutralizing antibodies (NAbs). However, studies in infectious strain JFH1-based culture systems expressing patient-derived Core-NS2 proteins have suggested neutralization resistance for specific HCV strains, in particular, of genotype 2. To further examine this phenomenon, we developed a panel of HCV genotype 2 recombinants for testing of sensitivity to neutralization by chronic-phase patient sera and lead human monoclonal antibodies (HMAbs). The novel Core-NS2 recombinants, with patient-derived genotype 2a (strain T9), 2b (strains DH8 and DH10), and 2c (strain S83) consensus sequences, were viable in Huh7.5 hepatoma cells without requirement for adaptive mutations, reaching HCV infectivity titers of 3.9-4.5 log10 focus-forming units per milliliter. In in vitro neutralization assays, we demonstrated that the novel genotype 2 viruses as well as prototype strains J6/JFH1(2a) and J8/JFH1(2b), all with authentic envelope proteins, were resistant to neutralization by genotype 2a, 2b, 2c, 2j, 2i, and 2q patient sera. However, these patient sera had high titers of HCV-specific NAbs, because they efficiently reduced the infectivity of J6(2a) and J8(2b) with deleted hypervariable region 1. The genotype 2a, 2b, and 2c viruses, found resistant to polyclonal patient sera neutralization, were efficiently neutralized by two lead HMAbs (AR4A and HC84.26). Using novel 2a, 2b, and 2c cell-culture systems, expressing authentic envelope proteins, we demonstrated resistance of HCV to patient-derived polyclonal high-titer NAbs. However, the same genotype 2 culture viruses were all sensitive to HMAbs recognizing conformational epitopes, indicating that neutralization resistance of HCV can be overcome by applying recombinant antibodies. These findings have important implications for HCV immunotherapy and vaccine development.

Genotype 1 Hepatitis C Virus Envelope Features That Determine Antiviral Response Assessed through Optimal Covariance Networks

The poor response to the combined antiviral therapy of pegylated alfa-interferon and ribavarin for hepatitis C virus (HCV) infection may be linked to mutations in the viral envelope gene E1E2 (env), which can result in escape from the immune response and higher efficacy of viral entry. Mutations that result in failure of therapy most likely require compensatory mutations to achieve sufficient change in envelope structure and function. Compensatory mutations were investigated by determining positions in the E1E2 gene where amino acids (aa) covaried across groups of individuals. We assessed networks of covarying positions in E1E2 sequences that differentiated sustained virological response (SVR) from non-response (NR) in 43 genotype 1a (17 SVR), and 49 genotype 1b (25 SVR) chronically HCV-infected individuals. Binary integer programming over covariance networks was used to extract aa combinations that differed between response groups. Genotype 1a E1E2 sequences exhibited higher degrees of covariance and clustered into 3 main groups while 1b sequences exhibited no clustering. Between 5 and 9 aa pairs were required to separate SVR from NR in each genotype. aa in hypervariable region 1 were 6 times more likely than chance to occur in the optimal networks. The pair 531–626 (EI) appeared frequently in the optimal networks and was present in 6 of 9 NR in one of the 1a clusters. The most frequent pairs representing SVR were 431–481 (EE), 500–522 (QA) in 1a, and 407–434 (AQ) in 1b. Optimal networks based on covarying aa pairs in HCV envelope can indicate features that are associated with failure or success to antiviral therapy.

The Evolutionary Rates of HCV Estimated with Subtype 1a and 1b Sequences over the ORF Length and in Different Genomic Regions

BackgroundConsiderable progress has been made in the HCV evolutionary analysis, since the software BEAST was released. However, prior information, especially the prior evolutionary rate, which plays a critical role in BEAST analysis, is always difficult to ascertain due to various uncertainties. Providing a proper prior HCV evolutionary rate is thus of great importance.Methods/Results176 full-length sequences of HCV subtype 1a and 144 of 1b were assembled by taking into consideration the balance of the sampling dates and the even dispersion in phylogenetic trees. According to the HCV genomic organization and biological functions, each dataset was partitioned into nine genomic regions and two routinely amplified regions. A uniform prior rate was applied to the BEAST analysis for each region and also the entire ORF. All the obtained posterior rates for 1a are of a magnitude of 10−3 substitutions/site/year and in a bell-shaped distribution. Significantly lower rates were estimated for 1b and some of the rate distribution curves resulted in a one-sided truncation, particularly under the exponential model. This indicates that some of the rates for subtype 1b are less accurate, so they were adjusted by including more sequences to improve the temporal structure.ConclusionAmong the various HCV subtypes and genomic regions, the evolutionary patterns are dissimilar. Therefore, an applied estimation of the HCV epidemic history requires the proper selection of the rate priors, which should match the actual dataset so that they can fit for the subtype, the genomic region and even the length. By referencing the findings here, future evolutionary analysis of the HCV subtype 1a and 1b datasets may become more accurate and hence prove useful for tracing their patterns.

Molecular epidemiology and putative origin of hepatitis C virus in random volunteers from Argentina

To study the subtype prevalence and the phylogenetic relatedness of hepatitis C virus (HCV) sequences obtained from the Argentine general population, a large cohort of individuals was analyzed. Healthy Argentinian volunteers (n = 6251) from 12 provinces representing all geographical regions of the country were studied. All parents or legal guardians of individuals younger than 18 years provided informed written consent for participation. The corresponding written permission from all municipal authorities was obtained from each city or town where subjects were to be included. HCV RNA reverse transcription-polymerase chain reaction products were sequenced and phylogenetically analyzed. The 5' untranslated region (5'UTR) was used for RNA detection and initial genotype classification. The NS5B polymerase region, encompassing nt 8262-8610, was used for subtyping. An unexpectedly low prevalence of HCV infection in the general population (0.32%) was observed. Our data contrasted with previous studies that reported rates ranging from 1.5% to 2.5%, mainly performed in selected populations of blood donors or vulnerable groups. The latter values are in keeping with the prevalence reported by the 2007 Argentinian HCV Consensus (approximately 2%). HCV subtypes were distributed as follows: 1a (25%), 1b (25%), 2c (25%), 3a (5%), and 2j (5%). Two isolates ascribed either to genotype 1 (5%) or to genotype 3 (5%) by 5'UTR phylogenetic analysis could not be subtyped. Subtype 1a sequences comprised a highly homogeneous population and clustered with United States sequences. Genotype 1b sequences represented a heterogeneous population, suggesting that this genotype might have been introduced from different sources. Most subtype 2c sequences clustered close to the 2c reported from Italy and Southern France. HCV has a low prevalence of 0.32% in the studied general population of Argentina. The pattern of HCV introduction and transmission in Argentina appears to be a consequence of multiple events and different for each subtype.