Detection Of Torque Teno Virus Research Articles

Detection and Genomic Characterization of Torque Teno Virus in Pneumoconiosis Patients in China.

Pneumoconiosis is a common occupational disease that can worsen with accompanying infection. Torque teno virus (TTV) is a prevalent human virus with multiple genotypes that can chronically and persistently infect individuals. However, the prevalence of TTV in pneumoconiosis patients is still unclear. This research aims to detect the presence and prevalence of TTV in the alveolar lavage fluid of pneumoconiosis patients in the Hunan Province of China using PCR. As a result, a 65.5% positive rate (19 out of 29) of TTV was detected. The TTV detection rate varies among different stages of silicosis and different pneumoconiosis patient ages. Nine novel TTV genomes ranging in size from 3719 to 3908 nt, named TTV HNPP1, HNPP2, HNPP3, HNPP4, HNPP5, HNPP6-1, HNPP6-2, HNPP7-1 and HNPP7-2, were identified. A genomic comparison and phylogenetic analysis indicated that these nine TTVs represent five different species with high genetic diversity which belong to the genus Alphatorquevirus. HNPP6-1 and HNPP6-2 belong to TTV3, HNPP5 belongs to TTV13, HNPP1 belongs to TTV24, HNPP4 belongs to TTV20, and the others belong to TTV19. The genomes of TTV HNPP1, HNPP6-1, and HNPP6-2 contain three putative open reading frames (ORFs) coding for proteins, ORF1, ORF2, and ORF3, while the other six TTV genomes contain two ORFs coding for proteins, ORF1 and ORF2. These results provide the first description of TTV epidemiology in pneumoconiosis patients in China. The newly identified TTV genome sequences reveal the high genetic diversity of TTV in pneumoconiosis patients and could contribute to a deeper understanding of TTV retention and infection in humans.

Detection of Torque Teno virus in IRAQI hemodialysispatients by ELISA technique

Background: Much evidence points to the presence of new factors that affect the liver in addition to the well-known hepatitis A-E viruses, and of these viruses is the Torque Teno virus, which was found to be more prevalent in the liver. 0bjecte: Detection of Torque Teno virus infection in patients undergoing dialysis with hepatitis C virus(HCV) patients and non-infected patients, comparing them with healthy people by ELISA technique to determine the extent of the virus spread in patients undergoing dialysis for the first time in the Iraqi community and how to affect the severity of infection. Methods: The study was conducted from 2021 until the end of 2022. Blood samples were collected from 35 patients infected with HCV undergoing hemodialysis, 35 patients not infected with HCV undergoing hemodialysis, and 20 healthy people. Clinical information and tests for hepatitis were obtained from the patients' registry. Chemical and hematological tests were done, and the results were recorded. A test for the detection of the Torque Teno virus was done by ELISA technology. Results: Torque Teno virus was detected in serum samples of patients using the ELISA technique. The infection rate was 0.0% in healthy people, (14.29%) in patients undergoing dialysis without HCV infection (5 out of 35) and (22.86%) in patients undergoing dialysis with HCV infection (8 out of 35), the novel result of this study showed that there is a higher prevalence of Torque Teno virus in HCV patients than in patients undergoing dialysis without HCV infection in Iraq. Also, this study found nonsignificant differences between Torque Teno virus infectionand liver function enzymes, neither with WBCs nor HB concentrations. Conclusion: Hepatitis may be caused by TTV, which was shown to be connected with biochemicalindicators of liver damage and persistent HBV or HCV infection. Keywords: Torque Teno virus, hemodialysis, ELISA technique

Detection of Torque Teno virus in IRAQI hemodialysis patients

Some data suggest that the liver is being affected by a new set of variables, and one of them is the Torque Teno virus, which is widespread in the liver other than the well-known hepatitis A-E viruses. Dialysis patients with hepatitis C virus (HCV) and those who are not HCV infected were compared to healthy persons using the nested PCR method to evaluate the extent of the viral dissemination in the Iraqi dialysis population and how it affects infection severity. The research began in 2021 until the end of 2022. Blood was drawn from 35 HCV-infected dialysis patients, 35 HCV-uninfected dialysis patients, and 20 healthy individuals. Immunological (ELISA), chemical and hematological testing findings were reported. In this study, molecular detection by nested PCR was performed to identify the Torque Teno virus. PCR identifies the Torque Teno virus in hemodialysis patient blood samples. The infection rate was 0% in healthy persons, 14.29% in dialysis patients without HCV (5 out of 13), and 20% in dialysis patients with HCV (7 out of 13). This research found a greater prevalence of the Torque Teno virus in HCV patients than in dialysis patients without HCV infection, and the detection of TTV by PCR technique was 100% for sensitivity specificity. This research demonstrated non-significant differences between Torque Teno virus infection and liver enzymes in hemodialysis patients. Keywords: Torque Teno virus, hemodialysis, Anelloviridae

Detection of Torquetenovirus and Redondovirus DNA in Saliva Samples from SARS-CoV-2-Positive and -Negative Subjects.

Torquetenovirus (TTV) and Redondovirus (ReDoV) are the most prevalent viruses found in the human respiratory virome in viral metagenomics studies. A large-scale epidemiological study was performed to investigate their prevalence and loads in saliva samples according to SARS-CoV-2 status. Saliva samples from 448 individuals (73% SARS-CoV-2 negative and 27% SARS-CoV-2 positive) aged 23-88 years were tested. SARS-CoV-2 and TTV were determined in saliva by specific qualitative and quantitative real-time PCRs, respectively. A sub-cohort of 377 subjects was additionally tested for the presence and load of ReDoV in saliva, and a different sub-cohort of 120 subjects for which paired saliva and plasma samples were available was tested for TTV and ReDoV viremia at the same timepoints as saliva. TTV in saliva was 72% prevalent in the entire cohort, at a mean DNA load of 4.6 log copies/mL, with no difference regardless of SARS-CoV-2 status. ReDoV was found in saliva from 61% of the entire cohort and was more prevalent in the SARS-CoV-2-negative subgroup (65% vs. 52%, respectively). In saliva, the total mean load of ReDoV was very similar to the one of TTV, with a value of 4.4 log copies/mL. The mean viral loads in subjects infected with a single virus, namely, those infected with TTV or ReDoV alone, was lower than in dually infected samples, and Tukey's multiple-comparison test showed that ReDoV single-infected samples resulted in the only true outlier (p = 0.004). Differently from TTV, ReDoV was not detected in any blood samples. This study establishes the prevalence and mean value of TTV and ReDoV in saliva samples and demonstrates the existence of differences between these two components of the human virome.

MOLECULAR AND PHYLOGENETIC DETECTION OF TORQUE TENO VIRUS (TTV) AMONG HEMODIALYSIS PATIENTS: A SINGLE CENTER STUDY

Background: Patients on long-term hemodialysis are at a higher risk of contracting blood transmitted infections because of their weakened immune systems and frequent interaction with blood, blood products, equipment, and contaminated surfaces. This making them an important population to study the clinical and epidemiological consequences of newly discovered infections like torque teno virus (TTV). Objective: To investigate the frequency of TTV in patients undergoing hemodialysis by molecular method and to find out any association with risk factors and liver function tests. Methods: This cross-sectional study conducted on (100) patients whom attending Hemodialysis Unit at Al-Imamein Al-Kadhimein Medical City in Baghdad, Iraq. The sample of the study consist of (58) males and (42) females, their mean age is (49.97±4.97 SD) years, (50) with viral hepatitis, while (50) without viral hepatitis, for a period from November 2020 to March 2021. Nested polymerase chain reaction (PCR) was used to detect TTV-DNA. TTV genogroup was determined by Sanger sequencing and phylogenetic tree construction. Results: TTV DNA was detected in 81% (81 out of 100) of hemodialysis patients, respectively. However, no significant association was found between demographic data, clinical characteristics and risk factors with TTV infection. Conclusion: This study showed high prevalence of TTV in hemodialysis patients but didn't play a role in liver injury among these patients. Also, based on phylogenetic analysis of the untranslated region (UTR), genogroup-3 was found to be the most prevalent in hemodialysis patients. Keywords: Torque teno virus, hemodialysis, risk factors, liver function, sequencing, phylogenetic tree Citation: Ali HM, Al-Shuwaikh AM, Manuti K. Molecular and phylogenetic detection of Torque Teno Virus (TTV) among hemodialysis patients: A single center study. Iraqi JMS. 2022; 20(1): 11-25. doi: 10.22578/IJMS.20.1.3

Better detection of Torque teno virus in children with leukemia by metagenomic sequencing than by quantitative PCR.

Torque teno virus (TTV) is a group of chronically persisting viruses with a short circular DNA genome. TTV demonstrates a wide sequence diversity and a large majority of humans are chronically infected by one or more types of TTV. AsTTV is ubiquitous, and viral replication correlates with immune status, TTV has been studied as a marker to assess global functional immune competence in transplant recipients. Most studies of the prevalence, amounts, and variation in TTV have been performed using PCR assays. We here present a comparison of the most frequently used quantitative PCR (qPCR) assay for TTV with shotgun metagenomic sequencing for detection and characterization of TTV in a cohort of pediatric cancer patients. The results show that TTV is more common than the qPCR assays indicate, and analysis of the TTV genome sequences indicate that a qPCR with primers and probe designed on a conserved region of the TTV genome may fail to detect some of the TTV strains found in this study.

Molecular Study of Torque Teno Virus in Patients with Acute Gastroenteritis.

Torque teno virus (TTV) is a single stranded non enveloped DNA virus. Various studies have found a high prevalence of TTV in different populations and in different human samples including blood and stool. The aim of the present study was to evaluate the prevalence of TTV in adult patients with acute gastroenteritis in stool samples by semi-nested polymerase chain reaction (PCR). This study was a retrospective, cross-sectional study carried out on 100 preserved stool samples from adult patients with simple community acquired diarrhea without dehydration. Stool samples were subjected to antigen detection of rotavirus and norovirus by enzyme linked immunosorbent assay (ELISA). Detection of TTV was performed by the use of semi- nested PCR. The detected viruses were TTV by semi-nested PCR in 83% of the patients, followed by both norovirus and rotavirus in 20% of patients each. TTV was present without any other studied virus in 52% of the samples, the norovirus antigen was detected as a single virus in 2%, and rotavirus was detected as a single virus in 3%. No viruses were detected in 11% of the stool samples. Norovirus was associated with TTV in 17 isolates and as a sole virus in three samples (p = 0.5). Rotavirus was associated with TTV in 17 isolates and alone in three. The data of the present study show a high prevalence of TTV in stool samples from adults with acute gastroenteritis. The presence of rotavirus and norovirus was also a common finding in these patients. There were no detected effects on the clinical features of gastroenteritis associated with the presence of TTV in acute gastroenteritis.

The Possible Role of Torque teno Virus in Kidney Allograft Recipients in a Sample of Iraqi Patients

Background: The use of immunosuppressive medications remains the most important challenge in renal transplantation because of the activation of many infections mainly viruses. The study was designed to evaluate the frequency of Torque teno virus (TTV) viremia among renal transplant recipients (RTR). Objective: To detect TTV in a sample of Iraqi RTR, and its association with renal functions. Methods: This cross-sectional study included 80 serum samples collected from RTR and subjected for TTV detection by real-time polymerase chain reaction (RT-PCR). Results: Qualitative RT-PCR run gave positive results for TTV in 45 out of 80 (56.25%) RTR, the results showed non-significant association between TTV and allograft rejection (p=0.26). Conclusion: TTV seems not associated with post transplantation renal impairment and/or kidney rejection. Keywords: Torque teno virus, renal transplantation, RTR Citation: Taher NM, Hussein MR, Al-Obaidi AB, Kadhim HS. The possible role of Torque teno virus in kidney allograft recipients in a sample of Iraqi patients. Iraqi JMS. 2020; 18(2): 130-137. doi: 10.22578/IJMS.18.2.7

High frequency of Torque Teno virus (TTV) among Egyptian hemodialysis patients

Very little reports are yet available for the infection rate of Torque Teno virus (TTV) among hemodialysis patients in Upper Egypt. Thus, the aim of this study was to assess the frequency and the possible genotypes of TTV in chronic renal failure patients undergoing dialysis. This cross-sectional study was carried out between August 2016 and February 2017 in three haemodialysis units in Minia, Egypt. Blood samples were collected for serological detection of Hepatitis B Virus (HBV) and Hepatitis C Virus (HCV) and for detection of TTV. Nested polymerase chain reaction (PCR) was used to detect TTV. Isolates genotypes were identified by sequencing of the N22 region and phylogenetic analysis was also performed. Out of 100 dialysis patients, 76 were TTV positive (52 males and 24 females), with no significant association with gender. TTV was significantly more common among young adults than in older patients. Increased period of haemodialysis posed a high risk for acquiring TTV: Odd Ratio (OR) = 1 and 95% Confidence Interval (CI)= 1.01-1.03. No association was noted between TTV infection and either HCV or HBV infection. Genogroup 1, especially genotype 2 was the most frequently found type in hemodialysis patients. TTV is vastly predominant among Egyptian haemodialysis patients with no significant association with HCV or HBV. Further analyses are recommended to associate the renal failure outcome with the virus load. Key words: Torque Teno virus, dialysis, phylogenetic biogeography.

<i>TORQUE TENO VIRUS</i>: PREVALENCE AND FEATURES OF PCR ANALYSIS

Objective: to study features of PCR analysis of TTV ( Torque teno virus ) viruses and their prevalence in patients with chronic liver diseases and in relatively healthy individuals. Material and methods. To conduct the research, polymerase chain reaction (PCR), electrophoretic detection, and statistical method were applied. 212 patients with chronic liver diseases and 125 relatively healthy individuals were examined. Results. TTV, TTMV and TTMDV DNAs in the main and control groups were detected. The data of absolute values, relative frequencies (confidence interval - 95% CI) of DNA detection of TTV, TTMDV, TTMV viruses and their various combinations in the control and main groups of patients are given. Conclusion. The work shows the predominance of mixed infections: TTV, TTMDV and TTMV DNAs were detected in 67 % and 72 % patients of the main and control groups, respectively. The combination of TTV + TTMV viruses was detected in 15.6 % patients of the main and in 12 % patients of the control group. Other combinations, as well as mono-infection of TTMDV and TTMV, were considerably less common and were only single instances. The absence of TTV, TTMV, TTMDV or their combinations in human organism is rare, the frequency of DNA detection of at least one of these viruses in the main and control groups is 95.3% and 89.6%, respectively, with no statistically significant difference.

Torquetenovirus detection in exosomes enriched vesicles circulating in human plasma samples

BackgroundTorquetenovirus (TTV) belongs to Anelloviridae family, infects nearly all people indefinitely without causing overt disease establishing a fine and successful interaction with the host. Increasing evidence have shown some human viruses exploit extracellular vesicles thereby helping viral persistence in the host. Here, the presence of TTV in extracellular vesicles circulating in human plasma was investigated.MethodsTTV DNA was quantified in plasma-derived exosomes from 122 samples collected from 97 diseased patients and 25 healthy donors. Exosomes enriched vesicles (EEVs) were extracted from plasma and characterized by Nanoparticle tracking analysis, by western blot for presence of tetraspanin CD63, CD81 and annexin II protein and, finally, by electron microscopy (EM). Presence and quantitation of TTV DNA were assessed with an universal single step real-time TaqMan PCR assay.ResultsPreliminary investigation showed that the human plasma extracted extracellular vesicles exhibited a main size of 70 nm, had concentration of 2.5 × 109/ml, and scored positive for tetraspanin CD63, CD81 and annexin II, typical characteristic of the exosomes vesicles. EEVs extracted from pooled plasma with TTV DNA viremia of 9.7 × 104 copies/ml showed to contain 6.3 × 102 TTV copies/ml, corresponding to 0.65% of total viral load. Important, TTV yield changed significantly following freezing/thawing, detergents and DNAse treatment of plasma before EEVs extraction. EEVs purified by sucrose-density gradient centrifugation and analysis of gradient fraction positive for exosomes marker CD63 harbored 102 TTV copies/ml. Moreover, EM evidenced the presence of TTV-like particles in EEVs. Successive investigation of plasma EEVs from 122 subjects (37 HIV-positive, 20 HCV infected, 20 HBV infected, 20 kidney transplant recipients, and 25 healthy) reported TTV DNA detection in 42 (34%) of the viremic samples (37 were from diseased patients and 5 from healthy people) at a mean level of 4.8 × 103 copies/ml. The examination of EEVs selected samples reported the presence of TTV genogroup 1, 3, 4 and 5, with genogroup 3 highly observed.ConclusionsCollectively, although these observations should be confirmed by further studies, circulation of TTV particles in EEVs opens new avenues and mechanistic insights on the molecular strategies adopted by anelloviruses to persist in the host.

Role of BK polyomavirus (BKV) and Torque teno virus (TTV) in liver transplant recipients with renal impairment.

Renal impairment is a common complication after liver transplantation (LT). While BK polyomavirus (BKV) has been linked to renal failure in kidney transplant recipients, Torque teno virus (TTV) is a surrogate marker for immunosuppression that does not have a clear association with any human disease. The impact of BKV and TTV on renal impairment after LT is unknown. In this retrospective study, urine and serum samples from 136 liver transplant recipients were screened for BKV and TTV by quantitative PCR. In addition, serum was screened for BKV-specific antibodies and the VP1 typing region was sequenced for BKV genotyping. All parameters were correlated with clinical data.Results/Key findings. BK viruria was detected up to 21 years after transplantation in 16.9 % of cases. BK viraemia was detected in 8.7 % of patients with BK viruria up to 4 years after LT. BKV-specific antibodies were detected in 93.6 % of all LT recipients and correlated with BKV viral load in urine. There was no correlation between renal impairment and the detection of BK DNA in urine (OR 0.983). TTV DNA was detected in 84.6 % of serum samples and in 66.6 % of urine samples. The TTV viral load in serum correlated with the BKV viral load but had no impact on renal impairment. Our data indicate that the detection of BKV and TTV is not a risk factor for renal impairment after LT. A correlation of TTV and BKV viral load seems to be an indicator for the immune status of the host.

Molecular Detection of Torque Teno Virus among HIV Seropositive Patients in Khartoum, Sudan

Molecular Detection of Torque Teno Virus among HIV Seropositive Patients in Khartoum, Sudan

Development of an Immunoassay for Detection of Torque Teno Virus (TTV) Antibodies Using the N22 Expression Product from TTV Genotype 2

Aims: This study describes an immunoassay to detect anti-torque teno virus (TTV) antibodies using a peptide obtained from expression of the N22 region of TTV genotype 2. Methods: The N22 region (∼500 bp) of TTV genotype 2 was cloned in a pET-28a(+) vector and expressed in ZYM-5052 autoinduction medium. Following metal affinity chromatography, a purified polypeptide was used as an antigen for the development of an immunoassay to detect anti-TTV antibodies in human sera. Results: Recombinant protein (∼25-kDa) was obtained after 24 h of incubation at 25°C in ZYM-5052 autoinduction medium. A blot assay developed using this polypeptide as an antigen and TTV-positive sera as the primary antibody produced a distinct spot on the nitrocellulose membrane. Serum samples from 36 of 42 patients with renal disease and 29 of 48 patients with liver diseases produced a positive signal using this immunoassay. Simultaneously, 18 of 48 healthy controls were also detected to be positive for anti-TTV antibodies. These results were found to be comparable with TTV detection using PCR, and the assay showed a high sensitivity and specificity (i.e., 97.44 and 91.67%, respectively). Moreover, this assay could detect TTV infection irrespectively of the genotype, including cases of mixed infection. Conclusion: The present immunoassay using the N22 expression product may be used as an alternative to PCR to detect TTV infection in large populations.

Association of age and gender with Torque teno virus detection in stools from diarrheic and non-diarrheic people

BackgroundTorque teno virus (TTV) is a small virus belongs to Anelloviridea family. TTV is a disease orphan virus but it has often been associated with a variety of pathologies and co-infections. TTV was recently identified as an infectious agent that could potentially be involved in cases of acute enteritis. ObjectivesTo ascertain the presence of TTV in stools from diarrheic and not diarrheic people, and to investigate an association between infection, and patient age and gender. Study designStool samples from people exhibiting signs of enteritis (954) and from non-diarrheic individuals (76) were collected in the former Chinook Health Region (CHR) in Southwestern Alberta, Canada from May 2008 to April 2009. Viral genetic material was extracted, and detection and quantification of TTV were carried out by real-time PCR. The presence of other viral and bacterial enteric pathogens was also investigated. ResultsMore (P<0.001) diarrheic people (38.8%) tested positive for TTV DNA than non-diarrheic individuals (18.4%). Furthermore, viral load was greater (P<0.001) in stools from diarrheic (2.0×107copies/g) than non-diarrheic (2.0×103copies/g) people. TTV DNA was detected most often in diarrheic individuals that were 0–5 (57.3%) and greater than 81 (59.0%) years of age. Combined across age, the prevalence of TTV was higher among men than women (P=0.003). Co-infections with other enteric pathogens were observed. ConclusionsThis study revealed a significant association between TTV prevalence and viral load, and enteritis. Also, TTV prevalence was significantly higher in the very young and elderly suggesting that immunological status is important.

Development of a new real time PCR quantitative assay for the detection of Torque teno virus (TTV): A new tool for immunomonitoring?

Development of a new real time PCR quantitative assay for the detection of Torque teno virus (TTV): A new tool for immunomonitoring?

Detection and genotyping of torque teno virus (TTV) in healthy blood donors and patients infected with HBV or HCV in Qatar.

Torque Teno virus (TTV) has been associated with non A-G hepatitis. The goal of this study was to estimate the infection rates and genotypic characteristics of TTV in the State of Qatar. A total of 644 blood samples representing different nationalities: (i) Qatari (118) and (ii) non-Qatari (526) nationals (mostly from Arab and South Eeast Asia countries) were tested for the presence of TTV DNA by nested PCR. The majority (573) of the blood samples belonged to healthy blood donors, whereas 54 and 53 of the blood samples belonged to patients infected with hepatitis B virus (HBV) and hepatitis C virus (HCV), respectively. The results obtained showed that the TTV infection rates in the healthy blood donors, and those infected with HBV or HCV patients were 81.4, 90.75 and 84.9%, respectively. Significant association between TTV viremia and age, or nationality was observed. Sequence analysis of PCR fragments amplified from the 5'-untranslated region (5'-UTR) of all (531) TTV positive samples showed that 65.5% (348/531) of the PCR fragment sequences were classified into main genogroup 3, followed by main genogroups 5 (24%), 2 (5.8%), and 1 (4.7%). Genogroup 4 was not detected among the our studied subjects. Phylogenetic and pairwise analyses using sequences from TTV viremic samples also showed an overall close similarity to the main genogroup 3. In conclusion, there was no significant difference in the rates of TTV detection among Qataris and non-Qataris and several genotypes, mainly genotype 3, were isolated.

Rapid Detection of Human Torque Teno Viruses Using High-Resolution Melting Analysis

Torque teno viruses (TTVs) are recently discovered DNA viruses, with heterogeneous genomes, highly prevalent in populations worldwide. The species that infect humans are Torque teno virus (TTV), Torque teno midi virus (TTMDV) and Torque teno mini virus (TTMV). High-resolution melting analysis (HRMA) is a sensitive and effective method for genotyping and mutation scanning. Up to now, HRMA has not been utilized for detection of TTVs. The aim of this study was to asses if HRMA is suitable for detecting TTVs variants. DNA was extracted from the blood and saliva of 13 healthy subjects for method optimization. Additionally, saliva samples from 100 healthy individuals were collected for estimating the TTVs' prevalence. Viral DNA was amplified by heminested polymerase chain reaction (PCR). Second round amplicons were used for the HRMA. The samples were analyzed using two fluorescent dyes, SYBR (®) Green I and EvaGreen®. The prevalence values for TTV, TTMDV and TTMV were 71.0, 31.0 and 54.0%, respectively. The three major melting curve patterns corresponding to TTV, TTMDV and TTMV on HRMA can be easily distinguished regardless of kit used. Our results showed that HRMA is a rapid and efficient method of detecting human TTVs.

Molecular detection of Torque teno virus in different breeds of swine

BackgroundTorque teno virus (TTV), of the Anelloviridae family, Iotatorquevirus genus, is a non-enveloped, single-stranded, and negative sense DNA (ssDNA) virus infecting human and many domestic animals including swines. Very little information is known about the investigations of TTV prevalence in different swine breeds so far.MethodsIn this study, 208 serum samples collected from seven swine breeds (Rongchang pig, Chenghua pig, Zibet pig, Wild boar, Duroc, Landrace, Large Yorkshire) from two independent farms were detected to determine the prevalence of two swine TTV genogroups, TTV1 and TTV 2, by nested polymerase chain reaction methods, and to analyse prevalence difference among these breeds.ResultsThe results showed that the prevalence of TTV in the seven breeds was 92%-100%. No significant difference (p > 0.05) in TTV infection was observed between different breeds. Interestingly, significantly higher prevalence for TTV1 in Rongchang boars (90%) and for TTV2 in Rongchang sows (95%) were detected, while co-infection rate (43.8%) was lower than other breeds. Sequence analysis showed that the homology of TTV1 and TTV2 were over 90.9% and 86.4% in these breeds, respectively.ConclusionsThe results indicated that TTV was widely distributed in the seven swine breeds. The prevalence of both TTV genogroups associated with swine breeds and genders. This study also respented the first description of swine TTV prevalence in different swine breeds. It was vitally necessary to further study swine TTV pathogenicity.

Torque Teno Virus 10 Isolated by Genome Amplification Techniques from a Patient with Concomitant Chronic Lymphocytic Leukemia and Polycythemia Vera

An infectious etiology has been proposed for many human cancers, but rarely have specific agents been identified. One difficulty has been the need to propagate cancer cells in vitro to produce the infectious agent in detectable quantity. We hypothesized that genome amplification from small numbers of cells could be adapted to circumvent this difficulty. A patient with concomitant chronic lymphocytic leukemia (CLL) and polycythemia vera (PV) requiring therapeutic phlebotomy donated a large amount of phlebotomized blood to test this possibility. Using genome amplification methods, we identified a new isolate (BIS8-17) of torque teno virus (TTV) 10. The presence of blood isolate sequence 8-17 (BIS8-17) in the original plasma was confirmed by polymerase chain reaction (PCR), validating the approach, since TTV is a known plasma virus. Subsequent PCR testing of plasmas from additional patients showed that BIS8-17 had a similar incidence (~20%) in CLL (n = 48) or PV (n = 10) compared with healthy controls (n = 52). CLL cells do not harbor BIS8-17; PCR did not detect it in CLL peripheral blood genomic deoxyribonucleic acid (DNA) (n = 20). CLL patient clinical outcome or prognostic markers (immunoglobulin heavy chain variable region [IGHV ] mutation, CD38 or zeta-chain associated protein kinase 70 kDa [ZAP-70]) did not correlate with BIS8-17 infection. Although not causative to our knowledge, this is the first reported isolation and detection of TTV in either CLL or PV. TTV could serve as a covirus with another infectious agent or TTV variant with rearranged genetic components that contribute to disease pathogenesis. These results prove that this method identifies infectious agents and provides an experimental methodology to test correlation with disease.