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1.
Viruses ; 14(2)2022 01 31.
Article in English | MEDLINE | ID: covidwho-1715767

ABSTRACT

INTRODUCTION: This study investigated the spontaneous clinical course of patients with endomyocardial biopsy (EMB)-proven lymphocytic myocarditis and cardiac human herpesvirus 6 (HHV6) DNA presence, and the effectiveness of steroid-based intervention in HHV6-positive patients. RESULTS: 756 heart failure (HF) patients underwent an EMB procedure to determine the underlying cause of unexplained HF. Low levels of HHV6 DNA, detectable by nested PCR only, were found in 10.4% of the cases (n = 79) of which 62% (n = 49) showed myocardial inflammation. The spontaneous course of patients with EMB-proven HHV6 DNA-associated lymphocytic myocarditis (n = 26) showed significant improvements in the left ventricular ejection fraction (LVEF) and clinical symptoms, respectively, in 15/26 (60%) patients, 3-12 months after disease onset. EMB mRNA expression of components of the NLRP3 inflammasome pathway and protein analysis of cardiac remodeling markers, analyzed by real-time PCR and MALDI mass spectrometry, respectively, did not differ between HHV6-positive and -negative patients. In another cohort of patients with ongoing symptoms related to lymphocytic myocarditis associated with cardiac levels of HHV6-DNA copy numbers <500 copies/µg cardiac DNA, quantified by real-time PCR, the efficacy and safety of steroid-based immunosuppression for six months was investigated. Steroid-based immunosuppression improved the LVEF (≥5%) in 8/10 patients and reduced cardiac inflammation in 7/10 patients, without an increase in cardiac HHV6 DNA levels in follow-up EMBs. CONCLUSION: Low HHV6 DNA levels are frequently detected in the myocardium, independent of inflammation. In patients with lymphocytic myocarditis with low levels of HHV6 DNA, the spontaneous clinical improvement is nearby 60%. In selected symptomatic patients with cardiac HHV6 DNA copy numbers less than 500 copies/µg cardiac DNA and without signs of an active systemic HHV6 infection, steroid-based therapy was found to be effective and safe. This finding needs to be further confirmed in large, randomized trials.


Subject(s)
Herpesvirus 6, Human/physiology , Immunosuppressive Agents/administration & dosage , Myocarditis/drug therapy , Myocarditis/virology , Roseolovirus Infections/drug therapy , Roseolovirus Infections/virology , Steroids/administration & dosage , Adult , Aged , Biopsy , Cohort Studies , DNA, Viral/genetics , Female , Gene Dosage , Herpesvirus 6, Human/genetics , Herpesvirus 6, Human/isolation & purification , Humans , Male , Middle Aged , Myocarditis/immunology , Myocarditis/physiopathology , NLR Family, Pyrin Domain-Containing 3 Protein/genetics , NLR Family, Pyrin Domain-Containing 3 Protein/immunology , Roseolovirus Infections/immunology , Roseolovirus Infections/physiopathology , Stroke Volume
2.
Viruses ; 14(2)2022 01 24.
Article in English | MEDLINE | ID: covidwho-1715759

ABSTRACT

A 67-year-old male veterinarian presented with fatigue, anorexia, and diarrhea. Although there were no tick bite marks, we suspected severe fever with thrombocytopenia syndrome (SFTS) due to bicytopenia, mild disturbance of consciousness, and a history of outdoor activities. Thus, we started immunoglobulin therapy immediately. A serum reverse transcription-polymerase chain reaction (RT-PCR) test for SFTS virus (SFTSV) was positive. The patient had treated a cat with thrombocytopenia 10 days prior to admission. The cat's serum SFTSV RT-PCR test result was positive, and the whole genome sequences of the patient's and cat's SFTSV were identical, suggesting the possibility of transmission from the cat to the patient. Other cases of direct cat-to-human SFTV transmission have been reported recently. Mucous membranes should be protected, including eye protection, in addition to standard precautions, when in contact with any cat with suspected SFTS.


Subject(s)
Cat Diseases/virology , Severe Fever with Thrombocytopenia Syndrome/transmission , Severe Fever with Thrombocytopenia Syndrome/virology , Aged , Animals , Cat Diseases/blood , Cats , DNA, Viral/blood , DNA, Viral/genetics , Humans , Male , Phlebovirus/classification , Phlebovirus/genetics , Phlebovirus/isolation & purification , Severe Fever with Thrombocytopenia Syndrome/blood , Severe Fever with Thrombocytopenia Syndrome/diagnosis , Veterinarians
3.
Cytokine ; 143: 155525, 2021 07.
Article in English | MEDLINE | ID: covidwho-1628419

ABSTRACT

Interferon gamma (IFN-γ) is a crucial cytokine in host immune response to hepatitis B virus (HBV) infection. This study aimed to determine whether a functional polymorphism +874T/A in IFN-γ gene linked to high and low producer phenotypes [IFN-γ (+874Thigh â†’ Alow)] may alter the outcomes of chronic HBV infection in Tunisian population. The +874T/A was analysed by ARMS-PCR method in the group of 200 patients chronically infected with HBV and 200 healthy controls. We observed that minor +874A allele, minor +874AA and +874TA genotypes were significantly more frequent in the chronic hepatitis B group in comparison to the control group [49 vs. 31%, P < 10-4; 24 vs. 13%, P < 10-4; 52 vs. 38%, P < 10-4; respectively]. Besides, they were associated with susceptibility to hepatitis B infection [OR = 2.15, 3.87 and 2.84, respectively]. The minor +874A allele and +874AA genotype were statistically more representative in the sub-group of patients with high viral DNA load when compared with the sub-group of patients with low HBV DNA load [(57% vs. 43%, P = 0.003, OR = 1.79); (33% vs. 14%, P = 0.003, OR = 3.59), respectively]. Collectively, our study suggests an association between the IFN-γ +874T/A SNP and persistence of HBV by the enhancement of HBV DNA replication.


Subject(s)
DNA Replication , Genetic Association Studies , Genetic Predisposition to Disease , Hepatitis B virus/physiology , Hepatitis B, Chronic/genetics , Interferon-gamma/genetics , Polymorphism, Single Nucleotide/genetics , Virus Replication/physiology , Adult , Alleles , Case-Control Studies , DNA, Viral/genetics , Female , Gene Frequency/genetics , Hepatitis B, Chronic/virology , Humans , Male , Viral Load/genetics
4.
Mol Biol Rep ; 49(4): 2847-2856, 2022 Apr.
Article in English | MEDLINE | ID: covidwho-1661716

ABSTRACT

BACKGROUND: Recombinase (uvsY and uvsX) from bacteriophage T4 is a key enzyme for recombinase polymerase amplification (RPA) that amplifies a target DNA sequence at a constant temperature with a single-stranded DNA-binding protein and a strand-displacing polymerase. The present study was conducted to examine the effects of the N- and C-terminal tags of uvsY on its function in RPA to detect SARS-CoV-2 DNA. METHODS: Untagged uvsY (uvsY-Δhis), N-terminal tagged uvsY (uvsY-Nhis), C-terminal tagged uvsY (uvsY-Chis), and N- and C-terminal tagged uvsY (uvsY-NChis) were expressed in Escherichia coli and purified. RPA reaction was carried out with the in vitro synthesized standard DNA at 41 °C. The amplified products were separated on agarose gels. RESULTS: The minimal initial copy numbers of standard DNA from which the amplified products were observed were 6 × 105, 60, 600, and 600 copies for the RPA with uvsY-Δhis, uvsY-Nhis, uvsY-Chis, and uvsY-NChis, respectively. The minimal reaction time at which the amplified products were observed were 20, 20, 30, and 20 min for the RPA with uvsY-Δhis, uvsY-Nhis, uvsY-Chis, and uvsY-NChis, respectively. The RPA with uvsY-Nhis exhibited clearer bands than that with either of other three uvsYs. CONCLUSIONS: The reaction efficiency of RPA with uvsY-Nhis was the highest, suggesting that uvsY-Nhis is suitable for use in RPA.


Subject(s)
Bacteriophage T4/enzymology , DNA, Viral/chemistry , DNA-Binding Proteins/chemistry , Membrane Proteins/chemistry , Nucleic Acid Amplification Techniques , SARS-CoV-2/chemistry , Viral Proteins/chemistry , DNA, Viral/genetics , SARS-CoV-2/genetics
5.
Comput Biol Chem ; 96: 107621, 2022 Feb.
Article in English | MEDLINE | ID: covidwho-1611674

ABSTRACT

Quantitative physicochemical perspective on life processes has been a great asset, in bioengineering and biotechnology. The quantitative physicochemical approach can be applied to practically all organisms, including viruses, if their chemical composition and thermodynamic properties are known. In this paper, a new method is suggested for determining elemental composition of viruses, based on atom counting. The atom counting method requires knowledge of genetic sequence, protein sequences and protein copy numbers. An algorithm was suggested for a program that finds elemental composition of various viruses (DNA or RNA, enveloped or non-enveloped). Except for the nucleic acid, capsid proteins, lipid bilayer and carbohydrates, this method includes membrane proteins, as well as spike proteins. The atom counting method has been compared with the existing molecular composition and geometric methods on 5 viruses of different morphology, as well as experimentally determined composition of the poliovirus. The atom counting method was found to be more accurate in most cases. The three methods were found to be complementary, since they require different kind of input information. Moreover, since the 3 methods rest on different assumptions, results of one model can be compared to those of the other two.


Subject(s)
Viruses/chemistry , Algorithms , Animals , Carbohydrates/chemistry , Chemical Phenomena , Computational Biology , DNA, Viral/chemistry , DNA, Viral/genetics , Elements , Environmental Science , Humans , Lipids/chemistry , RNA, Viral/chemistry , RNA, Viral/genetics , SARS-CoV-2/chemistry , SARS-CoV-2/genetics , Thermodynamics , Viral Proteins/chemistry , Viral Proteins/genetics , Viruses/genetics
7.
ACS Synth Biol ; 10(12): 3595-3599, 2021 12 17.
Article in English | MEDLINE | ID: covidwho-1517598

ABSTRACT

The novel respiratory virus SARS-CoV-2 is rapidly evolving across the world with the potential of increasing its transmission and the induced disease. Here, we applied the CRISPR-Cas12a system to detect, without the need of sequencing, SARS-CoV-2 genomes harboring the E484K mutation, first identified in the Beta variant and catalogued as an escape mutation. The E484K mutation creates a canonical protospacer adjacent motif for Cas12a recognition in the resulting DNA amplicon, which was exploited to obtain a differential readout. We analyzed a series of fecal samples from hospitalized patients in Valencia (Spain), finding one infection with SARS-CoV-2 harboring the E484K mutation, which was then confirmed by sequencing. Overall, these results suggest that CRISPR diagnostics can be a useful tool in epidemiology to monitor the spread of escape mutations.


Subject(s)
COVID-19 Testing/methods , COVID-19/diagnosis , CRISPR-Cas Systems , DNA, Viral/genetics , Mutation , SARS-CoV-2/genetics , Biosensing Techniques , COVID-19/virology , DNA/analysis , Genetic Techniques , HEK293 Cells , Humans , Immunoglobulin G/chemistry , Peptide Library , Polymers/chemistry , Spain/epidemiology , Surface Plasmon Resonance
8.
J Vet Sci ; 22(6): e70, 2021 Nov.
Article in English | MEDLINE | ID: covidwho-1485292

ABSTRACT

Bats are an important reservoir of several zoonotic diseases. However, the circulation of bat coronaviruses (BatCoV) in live animal markets in Indonesia has not been reported. Genetic characterization of BatCoV was performed by sequencing partial RdRp genes. Real-time polymerase chain reaction based on nucleocapsid protein (N) gene and Enzyme-linked immunosorbent assay against the N protein were conducted to detect the presence of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) viral RNA and antibody, respectively. We identified the presence of BatCoV on Cynopterus brachyotis, Macroglossus minimus, and Rousettus amplexicaudatus. The results showed that the BatCoV included in this study are from an unclassified coronavirus group. Notably, SARS-CoV-2 viral RNA and antibodies were not detected in the sampled bats.


Subject(s)
Chiroptera/virology , Coronavirus/classification , Coronavirus/isolation & purification , Animals , Coronavirus/genetics , DNA, Viral/genetics , Enzyme-Linked Immunosorbent Assay/veterinary , Indonesia , Nucleocapsid Proteins/genetics , Real-Time Polymerase Chain Reaction/veterinary , Reverse Transcriptase Polymerase Chain Reaction/veterinary , Species Specificity
9.
PLoS One ; 16(10): e0252846, 2021.
Article in English | MEDLINE | ID: covidwho-1468153

ABSTRACT

Cassava plantations in an area of 458 hectares spanning five provinces along the Thailand-Cambodia border were surveyed from October 2018 to July 2019 to determine the prevalence of cassava mosaic disease (CMD) caused by Sri Lankan cassava mosaic virus (SLCMV) in the region. CMD prevalence was 40% in the whole area and 80% in Prachinburi, 43% in Sakaeo, 37% in Burium, 25% in Surin, and 19% in Sisaket provinces. Disease incidence of CMD was highest 43.08% in Sakaeo, followed by 26.78% in Prachinburi, 7% in Burium, 2.58% in Surin, and 1.25% in Sisaket provinces. Disease severity of CMD symptoms was mild chlorosis to moderate mosaic (2-3). The greatest disease severity was recorded in Prachinburi and Sakaeo provinces. Asymptomatic plants were identified in Surin (12%), Prachinburi (5%), Sakaeo (0.2%), and Buriram (0.1%) by PCR analysis. Cassava cultivars CMR-89 and Huai Bong 80 were susceptible to CMD. In 95% of cases, the infection was transmitted by whiteflies (Bemisia tabaci), which were abundant in Sakaeo, Buriram, and Prachinburi but were sparse in Surin; their densities were highest in May and June 2019. Nucleotide sequencing of the mitochondrial cytochrome oxidase 1 (mtCO1) gene of whiteflies in Thailand revealed that it was similar to the mtCO1 gene of Asia II 1 whitefly. Furthermore, the AV1 gene of SLCMV-which encodes the capsid protein-showed 90% nucleotide identity with SLCMV. Phylogenetic analysis of completed nucleotide sequences of DNA-A and DNA-B components of the SLCMV genome determined by rolling circle amplification (RCA) indicated that they were similar to the nucleotide sequence of SLCMV isolates from Thailand, Vietnam, and Cambodia. These results provide important insights into the distribution, impact, and spread of CMD and SLCMV in Thailand.


Subject(s)
Begomovirus/genetics , Animals , Base Sequence/genetics , Cambodia , DNA, Viral/genetics , Hemiptera/virology , Plant Diseases/virology , Plants/virology , Thailand , Vietnam
10.
Cancer Prev Res (Phila) ; 14(10): 919-926, 2021 10.
Article in English | MEDLINE | ID: covidwho-1450634

ABSTRACT

The World Health Organization global call to eliminate cervical cancer encourages countries to consider introducing or improving cervical cancer screening programs. Brazil's Unified Health System (SUS) is among the world's largest public health systems offering free cytology testing, follow-up colposcopy, and treatment. Yet, health care networks across the country have unequal infrastructure, human resources, equipment, and supplies resulting in uneven program performance and large disparities in cervical cancer incidence and mortality. An effective screening program needs multiple strategies feasible for each community's reality, facilitating coverage and follow-up adherence. Prioritizing those at highest risk with tests that better stratify risk will limit inefficiencies, improving program impact across different resource settings. Highly sensitive human papillomavirus (HPV)-DNA testing performs better than cytology and, with self-collection closer to homes and workplaces, improves access, even in remote regions. Molecular triage strategies like HPV genotyping can identify from the same self-collected sample, those at highest risk requiring follow-up. If proven acceptable, affordable, cost-effective, and efficient in the Brazilian context, these strategies would increase coverage while removing the need for speculum exams for routine screening and reducing follow-up visits. SUS could implement a nationwide organized program that accommodates heterogenous settings across Brazil, informing a variety of screening programs worldwide.


Subject(s)
COVID-19/complications , Cytodiagnosis/methods , Early Detection of Cancer/methods , Papillomaviridae/isolation & purification , Papillomavirus Infections/complications , SARS-CoV-2/isolation & purification , Uterine Cervical Neoplasms/diagnosis , Brazil/epidemiology , DNA, Viral/analysis , DNA, Viral/genetics , Female , Humans , Papillomavirus Infections/genetics , Papillomavirus Infections/virology , Uterine Cervical Neoplasms/epidemiology , Uterine Cervical Neoplasms/virology
11.
Microbiol Spectr ; 9(2): e0031321, 2021 10 31.
Article in English | MEDLINE | ID: covidwho-1410326

ABSTRACT

The coronavirus disease 2019 (COVID-19) pandemic has brought about the unprecedented expansion of highly sensitive molecular diagnostics as a primary infection control strategy. At the same time, many laboratories have shifted focus to severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) research and diagnostic development, leading to large-scale production of SARS-CoV-2 nucleic acids that can interfere with these tests. We have identified multiple instances, in independent laboratories, in which nucleic acids generated in research settings are suspected to have caused researchers to test positive for SARS-CoV-2 in surveillance testing. In some cases, the affected individuals did not work directly with these nucleic acids but were exposed via a contaminated surface or object. Though researchers have long been vigilant of DNA contaminants, the transfer of these contaminants to SARS-CoV-2 testing samples can result in anomalous test results. The impact of these incidents stretches into the public sphere, placing additional burdens on public health resources, placing affected researchers and their contacts in isolation and quarantine, removing them from the testing pool for 3 months, and carrying the potential to trigger shutdowns of classrooms and workplaces. We report our observations as a call for increased stewardship over nucleic acids with the potential to impact both the use and development of diagnostics. IMPORTANCE To meet the challenges imposed by the COVID-19 pandemic, research laboratories shifted their focus and clinical diagnostic laboratories developed and utilized new assays. Nucleic acid-based testing became widespread and, for the first time, was used as a prophylactic measure. We report 15 cases of researchers at two institutes testing positive for SARS-CoV-2 on routine surveillance tests, in the absence of any symptoms or transmission. These researchers were likely contaminated with nonhazardous nucleic acids generated in the laboratory in the course of developing new SARS-CoV-2 diagnostics. These contaminating nucleic acids were persistent and widespread throughout the laboratory. We report these findings as a cautionary tale to those working with nucleic acids used in diagnostic testing and as a call for careful stewardship of diagnostically relevant molecules. Our conclusions are especially relevant as at-home COVID-19 testing gains traction in the marketplace and these amplicons may impact on the general public.


Subject(s)
COVID-19 Nucleic Acid Testing/methods , COVID-19/diagnosis , DNA Contamination , DNA, Viral/genetics , SARS-CoV-2/genetics , False Positive Reactions , Humans , Molecular Diagnostic Techniques , RNA, Viral/genetics , SARS-CoV-2/isolation & purification
12.
Transfus Med ; 31(5): 371-376, 2021 Oct.
Article in English | MEDLINE | ID: covidwho-1356901

ABSTRACT

BACKGROUND: Pathogen reduction technologies (PRT) based on nucleic-acid damaging chemicals and/or irradiation are increasingly being used to increase safety of blood components against emerging pathogens, such as convalescent plasma in the ongoing COVID-19 pandemic. Current methods for PRT validation are limited by the resources available to the blood component manufacturer, and quality control rely over pathogen spiking and hence invariably require sacrifice of the tested blood units: quantitative real-time PCR is the current pathogen detection method but, due to the high likelihood of detecting nonviable fragments, requires downstream pathogen culture. We propose here a new molecular validation of PRT based on the highly prevalent human symbiont torquetenovirus (TTV) and rolling circle amplification (RCA). MATERIALS AND METHODS: Serial apheresis plasma donations were tested for TTV before and after inactivation with Intercept® PRT using real-time quantitative PCR (conventional validation), RCA followed by real-time PCR (our validation), and reverse PCR (for cross-validation). RESULTS: While only 20% of inactivated units showed significant decrease in TTV viral load using real-time qPCR, all donations tested with RCA followed by real-time PCR showed TTV reductions. As further validation, 2 units were additionally tested with reverse PCR, which confirmed absence of entire circular genomes. DISCUSSION: We have described and validated a conservative and easy-to-setup protocol for molecular validation of PRT based on RCA and real-time PCR for TTV.


Subject(s)
DNA, Viral , Real-Time Polymerase Chain Reaction , Torque teno virus , Virus Inactivation , COVID-19/blood , COVID-19/genetics , DNA, Viral/blood , DNA, Viral/genetics , Humans , SARS-CoV-2/genetics , SARS-CoV-2/metabolism , Torque teno virus/genetics , Torque teno virus/metabolism
13.
Cell Rep ; 36(7): 109530, 2021 08 17.
Article in English | MEDLINE | ID: covidwho-1330686

ABSTRACT

A recent study proposed that severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) hijacks the LINE-1 (L1) retrotransposition machinery to integrate into the DNA of infected cells. If confirmed, this finding could have significant clinical implications. Here, we apply deep (>50×) long-read Oxford Nanopore Technologies (ONT) sequencing to HEK293T cells infected with SARS-CoV-2 and do not find the virus integrated into the genome. By examining ONT data from separate HEK293T cultivars, we completely resolve 78 L1 insertions arising in vitro in the absence of L1 overexpression systems. ONT sequencing applied to hepatitis B virus (HBV)-positive liver cancer tissues located a single HBV insertion. These experiments demonstrate reliable resolution of retrotransposon and exogenous virus insertions by ONT sequencing. That we find no evidence of SARS-CoV-2 integration suggests that such events are, at most, extremely rare in vivo and therefore are unlikely to drive oncogenesis or explain post-recovery detection of the virus.


Subject(s)
COVID-19/virology , DNA, Viral/genetics , Genome, Human , SARS-CoV-2/genetics , Sequence Analysis, DNA , Virus Integration , Aged , Animals , COVID-19/diagnosis , Carcinoma, Hepatocellular/virology , Chlorocebus aethiops , HEK293 Cells , Hepatitis B virus/genetics , Host-Pathogen Interactions , Humans , Liver Neoplasms/virology , Long Interspersed Nucleotide Elements , Male , Nanopore Sequencing , Vero Cells
14.
Comput Math Methods Med ; 2021: 1835056, 2021.
Article in English | MEDLINE | ID: covidwho-1315820

ABSTRACT

In a general computational context for biomedical data analysis, DNA sequence classification is a crucial challenge. Several machine learning techniques have used to complete this task in recent years successfully. Identification and classification of viruses are essential to avoid an outbreak like COVID-19. Regardless, the feature selection process remains the most challenging aspect of the issue. The most commonly used representations worsen the case of high dimensionality, and sequences lack explicit features. It also helps in detecting the effect of viruses and drug design. In recent days, deep learning (DL) models can automatically extract the features from the input. In this work, we employed CNN, CNN-LSTM, and CNN-Bidirectional LSTM architectures using Label and K-mer encoding for DNA sequence classification. The models are evaluated on different classification metrics. From the experimental results, the CNN and CNN-Bidirectional LSTM with K-mer encoding offers high accuracy with 93.16% and 93.13%, respectively, on testing data.


Subject(s)
COVID-19/virology , High-Throughput Nucleotide Sequencing/statistics & numerical data , Neural Networks, Computer , SARS-CoV-2/genetics , Sequence Analysis, DNA/statistics & numerical data , Base Sequence , Computational Biology , DNA, Viral/classification , DNA, Viral/genetics , Databases, Nucleic Acid/statistics & numerical data , Deep Learning , Humans , Pandemics , SARS-CoV-2/classification
15.
Sci Rep ; 11(1): 14558, 2021 07 15.
Article in English | MEDLINE | ID: covidwho-1315608

ABSTRACT

Whereas accelerated attention beclouded early stages of the coronavirus spread, knowledge of actual pathogenicity and origin of possible sub-strains remained unclear. By harvesting the Global initiative on Sharing All Influenza Data (GISAID) database ( https://www.gisaid.org/ ), between December 2019 and January 15, 2021, a total of 8864 human SARS-CoV-2 complete genome sequences processed by gender, across 6 continents (88 countries) of the world, Antarctica exempt, were analyzed. We hypothesized that data speak for itself and can discern true and explainable patterns of the disease. Identical genome diversity and pattern correlates analysis performed using a hybrid of biotechnology and machine learning methods corroborate the emergence of inter- and intra- SARS-CoV-2 sub-strains transmission and sustain an increase in sub-strains within the various continents, with nucleotide mutations dynamically varying between individuals in close association with the virus as it adapts to its host/environment. Interestingly, some viral sub-strain patterns progressively transformed into new sub-strain clusters indicating varying amino acid, and strong nucleotide association derived from same lineage. A novel cognitive approach to knowledge mining helped the discovery of transmission routes and seamless contact tracing protocol. Our classification results were better than state-of-the-art methods, indicating a more robust system for predicting emerging or new viral sub-strain(s). The results therefore offer explanations for the growing concerns about the virus and its next wave(s). A future direction of this work is a defuzzification of confusable pattern clusters for precise intra-country SARS-CoV-2 sub-strains analytics.


Subject(s)
COVID-19/virology , SARS-CoV-2/genetics , Sequence Analysis, DNA/methods , COVID-19/epidemiology , COVID-19/transmission , Computational Biology/methods , DNA, Viral/genetics , Databases, Genetic , Forecasting/methods , Genome, Viral , Humans , Machine Learning , Mutation , Phylogeny , SARS-CoV-2/classification , SARS-CoV-2/pathogenicity , Whole Genome Sequencing/methods
16.
Viruses ; 13(6)2021 05 30.
Article in English | MEDLINE | ID: covidwho-1286939

ABSTRACT

Feline panleukopenia is a severe disease of cats caused by feline parvovirus (FPV), and marginally canine parvovirus (CPV). Despite being less rapid than CPV, FPV evolution deserves attention, especially since outbreaks of particular severity are currently reported. This apparently different virulence needs monitoring from genetic and clinical points of view. This manuscript explored FPV molecular epidemiology at both Italian and international levels and the possible association between viral phylogeny and disease severity. Sequences from clinical cases of feline panleukopenia in Italy were obtained from 2011 to 2019, and the etiological agent was characterized, distinguishing FPV from CPV. Phylogenetic and phylodynamic analyses were conducted on Italian and international sequences. Moreover, the association between the viral sequence and clinical variables was evaluated on a group of highly characterized patients. After its origin in the 1920s, FPV showed a constant population size until a more recent expansion since 2000. Few long-distance introduction events characterized FPV spreading, however, most of its evolution occurred locally. Although without a strong statistical association, several clinical variables appeared influenced by viral phylogeny, suggesting a differential virulence potentially characterizing FPV strains. These results stress the importance of the continuous study of viral evolution and its repercussions on the disease clinical aspects.


Subject(s)
Cat Diseases/virology , Evolution, Molecular , Feline Panleukopenia Virus/classification , Feline Panleukopenia Virus/genetics , Feline Panleukopenia/epidemiology , Phylogeny , Animals , Cat Diseases/epidemiology , Cats , DNA, Viral/genetics , Dog Diseases/virology , Dogs , Feline Panleukopenia/virology , Italy/epidemiology , Parvovirus, Canine/genetics
17.
Viruses ; 13(6)2021 06 12.
Article in English | MEDLINE | ID: covidwho-1282640

ABSTRACT

There is a growing number of perinatally HIV-1-infected children worldwide who must maintain life-long ART. In early life, HIV-1 infection is established in an immunologically inexperienced environment in which maternal ART and immune dynamics during pregnancy play a role in reservoir establishment. Children that initiated early antiretroviral therapy (ART) and maintained long-term suppression of viremia have smaller and less diverse HIV reservoirs than adults, although their proviral landscape during ART is reported to be similar to that of adults. The ability of these early infected cells to persist long-term through clonal expansion poses a major barrier to finding a cure. Furthermore, the effects of life-long HIV persistence and ART are yet to be understood, but growing evidence suggests that these individuals are at an increased risk for developing non-AIDS-related comorbidities, which underscores the need for an HIV cure.


Subject(s)
Anti-Retroviral Agents/therapeutic use , Antiretroviral Therapy, Highly Active , Disease Reservoirs/virology , HIV Infections/virology , HIV-1/pathogenicity , Child , DNA, Viral/genetics , Female , HIV-1/genetics , Humans , Infectious Disease Transmission, Vertical , Pregnancy , Proviruses/genetics , Viral Load , Viremia/drug therapy
18.
J Med Virol ; 93(7): 4182-4197, 2021 07.
Article in English | MEDLINE | ID: covidwho-1263089

ABSTRACT

High-throughput droplet-based digital PCR (ddPCR) is a refinement of the conventional polymerase chain reaction (PCR) methods. In ddPCR, DNA/RNA is encapsulated stochastically inside the microdroplets as reaction chambers. A small percentage of the reaction chamber contains one or fewer copies of the DNA or RNA. After PCR amplification, concentrations are determined based on the proportion of nonfluorescent partitions through the Poisson distribution. Some of the main features of ddPCR include high sensitivity and specificity, absolute quantification without a standard curve, high reproducibility, good tolerance to PCR inhibitor, and high efficacy compared to conventional molecular methods. These advantages make ddPCR a valuable addition to the virologist's toolbox. The following review outlines the recent technological advances in ddPCR methods and their applications in viral identification.


Subject(s)
DNA, Viral/genetics , RNA, Viral/genetics , Real-Time Polymerase Chain Reaction/methods , High-Throughput Nucleotide Sequencing , Humans , Reproducibility of Results , Sensitivity and Specificity
19.
Virus Res ; 302: 198466, 2021 09.
Article in English | MEDLINE | ID: covidwho-1253729

ABSTRACT

Vigorous vaccination programs against SARS-CoV-2-causing Covid-19 are the major chance to fight this dreadful pandemic. The currently administered vaccines depend on adenovirus DNA vectors or on SARS-CoV-2 mRNA that might become reverse transcribed into DNA, however infrequently. In some societies, people have become sensitized against the potential short- or long-term side effects of foreign DNA being injected into humans. In my laboratory, the fate of foreign DNA in mammalian (human) cells and organisms has been investigated for many years. In this review, a summary of the results obtained will be presented. This synopsis has been put in the evolutionary context of retrotransposon insertions into pre-human genomes millions of years ago. In addition, studies on adenovirus vector-based DNA, on the fate of food-ingested DNA as well as the long-term persistence of SARS-CoV-2 RNA/DNA will be described. Actual integration of viral DNA molecules and of adenovirus vector DNA will likely be chance events whose frequency and epigenetic consequences cannot with certainty be assessed. The review also addresses problems of remaining adenoviral gene expression in adenoviral-based vectors and their role in side effects of vaccines. Eventually, it will come down to weighing the possible risks of genomic insertions of vaccine-associated foreign DNA and unknown levels of vector-carried adenoviral gene expression versus protection against the dangers of Covid-19. A decision in favor of vaccination against life-threatening disease appears prudent. Informing the public about the complexities of biology will be a reliable guide when having to reach personal decisions about vaccinations.


Subject(s)
Adenoviridae/genetics , COVID-19 Vaccines/genetics , COVID-19/prevention & control , Genome, Human/genetics , Pandemics , SARS-CoV-2/immunology , Vaccination , COVID-19/epidemiology , COVID-19/virology , DNA, Viral/genetics , Gene Expression , Genetic Vectors/genetics , Humans , RNA, Messenger/genetics , RNA, Viral/genetics , SARS-CoV-2/genetics
20.
Methods ; 201: 49-64, 2022 May.
Article in English | MEDLINE | ID: covidwho-1213579

ABSTRACT

Sensitive detection of viral nucleic acids is critically important for diagnosis and monitoring of the progression of infectious diseases such as those caused by SARS-CoV2, HIV-1, and other viruses. In HIV-1 infection cases, assessing the efficacy of treatment interventions that are superimposed on combination antiretroviral therapy (cART) has benefited tremendously from the development of sensitive HIV-1 DNA and RNA quantitation assays. Simian immunodeficiency virus (SIV) infection of Rhesus macaques is similar in many key aspects to human HIV-1 infection and consequently this non-human primate (NHP) model has and continues to prove instrumental in evaluating HIV prevention, treatment and eradication approaches. Cell and tissue associated HIV-1 viral nucleic acids have been found to serve as useful predictors of disease outcome and indicators of treatment efficacy, highlighting the value of and the need for sensitive detection of viruses in cells/tissues from infected individuals or animal models. However, viral nucleic acid detection and quantitation in such sample sources can often be complicated by high nucleic acid input (that is required to detect ultralow level viruses in, for example, cure research) or inhibitors, leading to reduced detection sensitivity and under-quantification, and confounded result interpretation. Here, we present a step-by-step procedure to quantitatively recover cell/tissue associated viral DNA and RNA, using SIV-infected Rhesus macaque cells and tissues as model systems, and subsequently quantify the viral DNA and RNA with an ultrasensitive SIV droplet digital PCR (ddPCR) assay and reverse transcription ddPCR (RT-ddPCR) assay, respectively, on the Raindance ddPCR platform. The procedure can be readily adapted for a broad range of applications where highly sensitive nucleic acid detection and quantitation are required.


Subject(s)
COVID-19 , HIV Infections , HIV-1 , Nucleic Acids , Simian Acquired Immunodeficiency Syndrome , Simian Immunodeficiency Virus , Animals , DNA, Viral/genetics , HIV-1/genetics , Macaca mulatta/genetics , Polymerase Chain Reaction/methods , RNA, Viral/analysis , RNA, Viral/genetics , SARS-CoV-2/genetics , Simian Acquired Immunodeficiency Syndrome/diagnosis , Simian Immunodeficiency Virus/genetics , Viral Load
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