TT virus infection in children and adults who visited a general hospital in the south of Brazil for routine procedure

Vasconcelos, H.; Menezes, María Elizabeth; Niel, Christian

doi:10.1590/s0074-02762001000400013

Cited by 14 publications

(11 citation statements)

References 20 publications

(14 reference statements)

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“…Despite its large spectrum, it has been shown that the Takahashi assay [2000b] is not able to amplify TTV DNAs from all positive samples [Biagini et al, 2000b;Vasconcelos et al, 2001], indicating the necessity to perform several PCR assays to assess the true TTV prevalence in a determined population . Thus, it cannot be excluded that some sera tested negative for TTV were in reality TTV positive.…”

Section: Discussionmentioning

confidence: 99%

High detection rates of TTV‐like mini virus sequences in sera from Brazilian blood donors*

Niel

Lampe

2001

Journal of Medical Virology

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TT virus (TTV) is an unenveloped virus with a single-stranded, circular DNA genome of 3,818-3,853 nucleotides (nt) that infects humans and non-human primates. Recently, the existence of a novel human virus, TTV-like mini virus (TLMV), that shows a genetic organization similar to that of TTV, but with smaller virion particle and genome, was proposed [Takahashi et al. (2000) Archives of Virology 145:979-993]. To date, no information is available with respect to the prevalence and pathogenicity of TLMV. A sensitive PCR assay was developed by using two oligonucleotide primers (LS2 and LA2) designed from the conserved non-coding region of the TLMV genome. One hundred thirty-seven sera from volunteer Brazilian blood donors were tested and 99 (72%) were TLMV DNA positive. No significant differences were observed between the groups of TLMV positive and negative subjects in relation to sex ratio, seroprevalence of TTV DNA, prevalence of anti-hepatitis A virus antibodies, area of residence, occurrence of daily contact with animals, family income, education level, and level of alanine aminotransferase. The specificity of the PCR assay was demonstrated after cloning of amplification products and determination of the nucleotide sequences (200-228 nt) of clones derived from 23 individuals. When DNAs extracted from TLMV/TTV-coinfected sera were submitted to PCR with LS2 and LA2 primers, the amplification products were derived exclusively from the TLMV genome. A markedly wide range of sequence divergence, even higher than that existent among TTV strains, was noted among TLMV isolates, with a maximum evolutionary distance of 0.80.

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Section: Discussionmentioning

confidence: 99%

High detection rates of TTV‐like mini virus sequences in sera from Brazilian blood donors*

Niel

Lampe

2001

Journal of Medical Virology

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“…One hundred fifty-two (83%) samples had been tested previously for TTV DNA by using three different PCR assays [Takahashi et al, 1998;Tanaka et al, 1998;Leary et al, 1999], and 68 (45%) positive by at least one PCR assay [Vasconcelos et al, 2001].…”

Section: Blood Samplesmentioning

confidence: 99%

“…The different sequences derived from the same patient could be very close genetically or very separated (percent nucleotide difference from 0.5% to more than 30%). Sequences derived from Most, but not all, serum samples have been tested previously for TTV DNA [Vasconcelos et al, 2001]. …”

Section: Phylogenetic Analysismentioning

confidence: 99%

Mixed infections of adults and children with multiple TTV‐like mini virus isolates

Vasconcelos

Cataldo

Niel

2002

Journal of Medical Virology

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Testing of the DNA of TTV-like mini virus (TLMV) was done with serum samples obtained from 184 patients (children and adults) who visited different outpatient clinics at a university hospital in Florianopolis, south of Brazil. TLMV DNA was detected by PCR primers from the non-coding region of the genome. A global TLMV prevalence of 78% was found (94% among children below 11 years). PCR products from three serum samples (patients A-C) were cloned, and the sequences with a length of 201-227 nucleotides were determined for 16-19 clones derived from each of the sera. Among the 16 clones derived from patient C, 15 were identical, and the remaining one had a sequence homology of 99%. In contrast, eight different sequences were obtained among the 19 clones derived from patient A, and 10 distinct sequences were depicted among the 17 clones derived from the serum of patient B. Additionally, 13 clones derived from a saliva sample of patient B were sequenced, and seven different nucleotide sequences obtained. One particular sequence was predominant in both serum (8/17 clones) and saliva (7/13 clones) of patient B. On a phylogenetic tree, sequences derived from patient A (a 6-year-old boy), as well as those derived from patient B (a 24-year-old man), were located in five distinct evolutionary branches, taking a minimum divergence of 5% between branches. This suggested that adults and children are coinfected frequently with several TLMV isolates of different origins.

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“…Concomitantly with the progressive characterization of Anellovirus genus members, the improvement of TTV PCR assays, which were initially unable to detect a wide range of genotypes, has led to increasing measurements of TTV prevalence in various populations (6,19,20). Much progress in TTV detection has been done since then, with the use of primers located in a short, highly conserved genomic region (15,21,22).…”

Section: Discussionmentioning

confidence: 99%

A multiplex PCR assay able to simultaneously detect Torque teno virus isolates from phylogenetic groups 1 to 5

Devalle¹,

Niel²

2005

Braz J Med Biol Res

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Torque teno virus (TTV) is a circular, single-stranded DNA virus that chronically infects healthy individuals of all ages worldwide. TTV has an extreme genetic heterogeneity which is reflected in its current classification into five main phylogenetic groups (1-5). Using specific PCR assays, it has been shown that many individuals are co-infected with TTV isolates belonging to different phylogenetic groups. Here, a multiplex PCR assay was developed, using five recombinant plasmids. Each plasmid carried an insert of different size issued from a TTV isolate belonging to a different group. The assay was able to simultaneously amplify DNAs of TTV isolates belonging to all five phylogenetic groups. Multiplex PCR was then tested satisfactorily on DNAs extracted from 55 serum samples (47 health care workers and 8 AIDS patients). All individuals but nine were infected with at least one TTV isolate. Co-infection with multiple isolates was found in 29/ 47 (62%) health care workers and in 8/8 (100%) AIDS patients. A number of discrepancies were observed when results obtained with three thermostable DNA polymerases were compared. For example, four TTV phylogenetic groups were detected in a particular serum sample by using one of the three DNA polymerases, whereas the other two enzymes were able to detect only three TTV groups. However, none of the three enzymes used could be broadly considered to be more efficient than the others. Despite its limitations, the assay described here constitutes a suitable tool to visualize the degree of coinfection of a given population, avoiding time-consuming experiments.

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TT virus infection in children and adults who visited a general hospital in the south of Brazil for routine procedure

Abstract: TT virus (TTV) is a newly described nonenveloped human virus

Cited by 14 publications

References 20 publications

High detection rates of TTV‐like mini virus sequences in sera from Brazilian blood donors*

High detection rates of TTV‐like mini virus sequences in sera from Brazilian blood donors*

Mixed infections of adults and children with multiple TTV‐like mini virus isolates

A multiplex PCR assay able to simultaneously detect Torque teno virus isolates from phylogenetic groups 1 to 5

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