Search Results (42)

The extensive use of antiviral substances (SASs) during and after the COVID-19 pandemic has increased their release into wastewater systems, raising concerns regarding their persistence and potential ecotoxicological effects. The primary objective of this study was to isolate bacterial strains from activated sludge (AS) that possess the ability to biodegrade SASs. From the AS sample, three bacterial species, Comamonas testosteroni (I2), Bacillus amyloliquefaciens (I3) and Bacillus mycoides (I4), were successfully isolated and identified. These strains were subsequently applied in biodegradation experiments targeting seven SASs: daclatasvir (DCV), darunavir (DRV), favipiravir (FAV), lopinavir (LOP), remdesivir (REM), ritonavir (RIT), and umifenovir (UMI). During the experiments, residual SAS concentrations, microbial growth parameters, physicochemical indicators and ecotoxicity were monitored. All three strains demonstrated substantial biodegradation potential, achieving reductions exceeding 90% for most tested compounds, with particularly low toxicity observed in experiments conducted with AS and Bacillus amyloliquefaciens. These findings highlight the relevance of AS-derived bacteria as promising candidates for enhancing SAS removal in wastewater treatment processes. Full article

People who use crack cocaine (PWUCC) constitute a key population due to vulnerability and marginalization, especially in a socio-ecologically diverse, relatively isolated region with limited public health infrastructure. This study aimed to perform a genetic characterization of circulating HCV among PWUCC in the municipality of Bragança, situated on the Brazilian Amazon coast, identifying viral genotypes, subtypes, resistance-associated substitutions (RAS)—naturally occurring mutations in the viral genome that can reduce the efficacy of direct-acting antiviral (DAA) agents—and predictions of phenotypic resistance. Methods: Between 2016 and 2018, biological samples and epidemiological data were obtained from 165 PWUCC. Viral detection was performed using RT-PCR, while genotyping, subtyping, and RAS profiling were conducted through nucleotide sequencing and fragment analysis. Results: In 165 PWUCC, 22 (13.3%) tested positive for HCV RNA. Most of them had not had access to public health services (91.5%), and more than half (57.0%) reported living in unstable housing conditions. HCV subtypes 1a (27.3%), 1b (40.9%), and 3a (31.8%) were detected. Evidence of resistance associated with DAAs, such as daclatasvir and dasabuvir, was detected in five PWUCC with HCV (22.7%). Conclusions: The high prevalence of HCV infection, predominantly subtype 1b, and significant levels of resistance are very concerning. This demonstrates the urgent need for targeted public health interventions to expand access to testing, treatment, and effective antiviral therapy in this vulnerable population of the Brazilian Amazon. Full article

Background/Objectives: Monkeypox is endemic to the African continent and has recently garnered global attention due to reported outbreaks in non-endemic nations. No approved drug is available for non-severe cases, and some isolates gained resistance to approved antivirals. In this study, we employed a drug repositioning strategy to evaluate the efficacy of existing FDA-approved antiviral drugs if repurposed for use against emerging Monkeypox, representing a cost-effective method for identifying novel therapeutic interventions. Methods: Methodology including Egyptian virus strain isolation, propagation and titration followed by in vitro studies, molecular docking and molecular dynamics simulations combined with binding free energy were carried out. Twenty-three FDA-approved drugs, including Abacavir, Acyclovir, Amantadine, Chloroquine, Daclatasvir, Dolutegravir, Entecavir, Favipiravir, Hydroxychloroquine, Lamivudine, Molnupiravir, Nevirapine, Oseltamivir, Penciclovir, Remdesivir, Ribavirin, Sofosbuvir, Tenofovir, Valaciclovir, Valganciclovir, Velpatasvir, Zanamivir, and Zidovudine, were screened for potential anti-monkeypox activity in vitro. In silico studies were carried out against three monkeypox proteins, Thymidylate Kinase, A42R Profilin-Like Protein, and VACV D13, to identify their potential targets. Results: In vitro testing showed that two antiviral drugs are positive. The employed computational methods indicate that remdesivir demonstrated superior binding patterns with elevated scores and stable complexes throughout the simulation. Conclusions: Our findings showed that Remdesivir therapeutic compound is potent against the tested strain of MPXV, and exhibited a robust binding affinity for Thymidylate Kinase, A42R Profilin-Like Protein, and VACV D13 enzymes, and thus may potentially be utilized as antiviral for the treatment of monkeypox virus. Full article

Background and Objectives: Hepatitis C virus (HCV) infection is highly prevalent among patients undergoing chronic hemodialysis in emerging countries and is associated with significant morbidity and mortality in this population. The objective of this study was to eradicate chronic HCV infection in patients undergoing chronic hemodialysis in Mauritania using a combination of sofosbuvir, 400 mg, and daclatasvir, 60 mg (direct acting antiviral—DAA—therapy), for 3 months. This was a prospective, single-arm, multicenter, interventional study. Materials and Methods: A total of 553 patients undergoing hemodialysis were screened for HCV across all hemodialysis centers nationwide. Biological parameters were compared before and after DAA therapy. Results: The prevalence of HCV infection was 6.8% (n = 38); two patients had undetectable HCV RNA. Out of the 36 eligible patients, 33 received DAA treatment. The median age of the patients was 49 (25–78) years. The average duration on hemodialysis was 9.4 (4–17) years. The median viral load before treatment was 538277 (10–4258571) IU/L. The median alanine aminotransferase (ALT) level was 52.3 (14–278) IU/L. The median hemoglobin level was 10 (6–13) g/dL. HCV viral load was undetectable at week 12 (W12) and week 24 (W24). The sustained virologic response (SVR) rate was 100%. Adverse events included one case of acute pancreatitis, six cases of fatigue (17%), five cases of headache (15%), four cases of diarrhea (12%), three cases of nausea (9%), and four cases of insomnia (12%). Conclusions: The combination of sofosbuvir and daclatasvir is effective in patients with HCV undergoing chronic hemodialysis, achieving a 100% SVR rate. Full article

While direct-acting antivirals (DAAs) are available for the treatment of chronic Hepatitis C virus (HCV) patients in Nepal, knowledge of the circulating genotypes/subtypes and drug target gene mutations of HCV is currently unavailable. Here, we describe HCV genotypes/subtypes and identify antiviral target gene mutations in patients at a tertiary care hospital using genome data. A cross-sectional study was conducted from December 2019 to February 2024, where PCR followed by whole genome sequencing was performed to identify HCV genotypes/subtypes and drug target gene mutations. Among all the patients who tested positive for anti-HCV, 70.6% (149/211) were HCV RNA positive, while 68.2% (30/44) were genotype/subtype 3a, followed by 1a (18.2%, 8/44) and others (13.6%, 6/44), including new subtypes 3g and 3i from Nepal. Subtype 3a was also the dominant subtype (≥70%) among intravenous drug users and sexual routes of transmission. We found 70.5% of the samples with resistant mutations in the NS3/4A region, 22.7% in NS5A, and 45.5% in NS5B. Resistant mutations against sofosbuvir, pibrentasvir, velpatasvir, daclatasvir, and dasabuvir were found at 25%, 18%, 16%, 16%, and 2%, respectively, mostly on subtype 3a. The predominant HCV genotype/subtype in our patient group was 3a, and resistance mutations against direct-acting antivirals were found in most untreated patients. Full article

Hepatitis C virus (HCV) is a global public health problem, but advancements in HCV treatment have improved the cure rate. This study evaluated the effectiveness of direct-acting antivirals (DAAs) in HCV-infected patients from May 2021 to April 2023 in collaboration with tertiary care hospitals in West Bengal. The HCV viral load was monitored via qRT-PCR. Sanger sequencing was performed to determine the HCV genotypes. The clinicians prescribed the patient treatment regime. The maximum number of patients in the study population (N = 398) were compensated cirrhosis patients (46.28%). The overall SVR rate of the study population was 94.47%. The decompensated cirrhosis patients experienced the lowest SVR rate (88.89%). The maximum number of patients were prescribed sofosbuvir/daclatasvir (63.77%), and the lowest SVR rate (93.23%) was observed with this treatment regime. In the study population, GT-3 was the predominant (67.43%) circulating genotype, followed by GT-1 and -4. Among 398 patients, 22 (5.53%) were non-responsive to DAA treatment. Out of these 22 non-responder patients, 77.27% (n = 17) were GT-3-infected (3a:10; 3b:07), followed by GT-1 (1c: 04; 1b: 01). Thus, increasing numbers of DAA non-responsive cases among HCV GT-3-infected and decompensated cirrhosis patients may pose serious threats in the future. Full article

Dendritic cells (DCs) play a crucial role in controlling viral infections. Little is known about the changes in frequencies of the DC subsets in patients with chronic hepatitis C (CHC), particularly in the era of interferon-free regimens. We aimed to evaluate the impact of sofosbuvir/daclatasvir on the frequency of different peripheral DC subsets, the expression of the inhibitory CD200R and its ligand CD200 on DC, and their relation to the treatment outcome. A total of 1000 patients with CHC were enrolled and treated with a fixed oral dose of 400 mg of sofosbuvir and 60 mg of daclatasvir for 12 weeks. A total of 940 patients achieved sustained virologic response (SVR), and only 60 patients were non-responders (NRs). The frequencies of the peripheral plasmacytoid (pDC) and myeloid (mDCs) subsets and their surface expressions of CD200R and CD200 molecules were analyzed using flow cytometry. This analysis included 60 non-responders (NR group), 60 randomly selected sustained virologic responders (SVR group) at baseline, and at the end of treatment, and 60 healthy controls. HCV infection was associated with a down-regulation in the frequency of mDC, compared to healthy controls. In addition, mDC in HCV-infected patients showed lower levels of CD200R. However, neither the pDC frequency nor their CD200R expression was significantly altered. Interestingly, by the end of therapy, the frequencies of circulating mDCs and CD200R⁺mDC increased significantly in the SVR group and were even comparable to healthy controls. The levels of these cells were not normalized in the NR group. Percentages of mDCs and CD200R⁺mDC subsets showed good prognostic accuracy for predicting virologic response to therapy. Our results showed that HCV infection was associated with modulation of the mDC frequency and their surface expression of CD200R. Successful daclatasvir and sofosbuvir combined therapy was associated with the normalization of the percentages of mDC and CD200R⁺mDC. Full article

Background: The advent of direct-acting antiviral (DAA) therapy has revolutionized the treatment landscape of the hepatitis C virus (HCV) infection. This study aimed to provide a comprehensive research study of the real-world effectiveness and safety of DAA treatment, representing the first study conducted in the Omani population. Methods: A cross-sectional study was conducted including 375 HCV patients with different genotypes, treated using different DAA regimens, with or without ribavirin, between January 2012 and December 2020 at the Sultan Qaboos University Hospital and the medical city for military and security services, two tertiary hospitals in Muscat, Oman. The rate of sustained virologic response 12 weeks after completing the regimen (SVR-12) was analyzed as the primary outcome. Secondary outcomes included treatment safety and adverse events related to DAA therapy, as reported by patients and treating physicians. Results: A total of 375 patients were included in the study, with a mean age of 47.3 ± 15.4 years. Most were male (59.2%) and treatment-naïve (71.7%). The prevalence of liver cirrhosis was 19.7%, while 4.0% had hepatocellular carcinoma (HCC). The SVR-12 rate among treatment-naïve and treatment-experienced patients was 95.0% and 93.4%, respectively. Several parameters were associated with DAA treatment failure, including liver cirrhosis (p = 0.004) and active HCC (p = 0.009). Following SVR-12, significant improvements were observed in alanine transaminase, bilirubin, and albumin levels, Fibrosis-4 Index, and liver stiffness measurements compared to baseline (p <0.001 each). No significant adverse effects were reported. Conclusions: Based on our real-world experience, DAAs are highly effective in treating patients with HCV infection in Oman, with an excellent tolerability and safety profile. Full article

The study of hepatitis C virus (HCV) replication in cell culture is mainly based on cloned viral isolates requiring adaptation for efficient replication in Huh7 hepatoma cells. The analysis of wild-type (WT) isolates was enabled by the expression of SEC14L2 and by inhibitors targeting deleterious host factors. Here, we aimed to optimize cell culture models to allow infection with HCV from patient sera. We used Huh7-Lunet cells ectopically expressing SEC14L2, CD81, and a GFP reporter with nuclear translocation upon cleavage by the HCV protease to study HCV replication, combined with a drug-based regimen for stimulation of non-modified wild-type isolates. RT-qPCR-based quantification of HCV infections using patient sera suffered from a high background in the daclatasvir-treated controls. We therefore established an automated image analysis pipeline based on imaging of whole wells and iterative training of a machine learning tool, using nuclear GFP localization as a readout for HCV infection. Upon visual validation of hits assigned by the automated image analysis, the method revealed no background in daclatasvir-treated samples. Thereby, infection events were found for 15 of 34 high titer HCV genotype (gt) 1b sera, revealing a significant correlation between serum titer and successful infection. We further show that transfection of viral RNA extracted from sera can be used in this model as well, albeit with so far limited efficiency. Overall, we generated a robust serum infection assay for gt1b isolates using semi-automated image analysis, which was superior to conventional RT-qPCR-based quantification of viral genomes. Full article

Coronavirus disease 2019 (COVID-19) still causes death in elderly and immunocompromised individuals, for whom the sustainability of the vaccine response may be limited. Antiviral treatments, such as remdesivir or molnupiravir, have demonstrated limited clinical efficacy. Nirmatrelvir, an acute respiratory syndrome coronavirus 2 (SARS-CoV-2) major protease inhibitor, is clinically effective but has been associated with viral rebound and antiviral resistance. It is thus necessary to study novel and repurposed antivirals for the treatment of COVID-19. We previously demonstrated that daclatasvir (DCV), an inhibitor of the hepatitis C virus (HCV) NS5A protein, impairs SARS-CoV-2 replication by targeting viral RNA polymerase and exonuclease, but the doses of DCV used to inhibit the new coronavirus are greater than the standard human plasma exposure for hepatitis C. Because any potential use of DCV against SARS-CoV-2 would be shorter than that reported here and short-term toxicological studies on DCV show that higher doses are tolerable, we searched for doses of DCV that could protect transgenic mice expressing the human ACE2 receptor (K18-hACE-2) from lethal challenge with SARS-CoV-2. We found that a dose of 60 mg/kg/day provides this protection by reducing virus replication and virus-induced lung insult. This dose is tolerable in different animal models. Taken together, our data provide preclinical evidence that can support phase I clinical trials to confirm the safety, tolerability, and pharmacokinetics of new doses of daclatasvir for a short duration in humans to further advance this compound’s utility against COVID-19. Full article

Hepatitis C virus (HCV) infection can lead to hepatic fibrosis. The advent of direct-acting antivirals (DAAs) has substantially improved sustained virological response (SVR) rates. In this context, kidney transplant recipients (KTRs) are of particular interest due to their higher HCV infection rates and uncertain renal excretion and bioavailability of DAAs. We investigated liver stiffness after DAA treatment in 15 HCV-infected KTRs using ultrasound shear wave elastography (SWE) in comparison with magnetic resonance elastography (MRE). KTRs were treated with DAAs (daclatasvir and sofosbuvir) for three months and underwent SWE at baseline, end of therapy (EOT), and 3 (EOT+3) and 12 months (EOT+12) after EOT. Fourteen patients achieved SVR12. Shear wave speed (SWS)—as a surrogate parameter for tissue stiffness—was substantially lower at all three post-therapeutic timepoints compared with baseline (EOT: −0.42 m/s, p < 0.01; CI = −0.75–−0.09, EOT+3: −0.43 m/s, p < 0.01; CI = −0.75–−0.11, and EOT+12: −0.52 m/s, p < 0.001; CI = −0.84–−0.19), suggesting liver regeneration after viral eradication and end of inflammation. Baseline SWS correlated positively with histopathological fibrosis scores (r = 0.48; CI = −0.11–0.85). Longitudinal results correlated moderately with APRI (r = 0.41; CI = 0.12–0.64) but not with FIB-4 scores (r = 0.12; CI = −0.19–0.41). Although higher on average, SWE-derived measurements correlated strongly with MRE (r = 0.64). In conclusion, SWE is suitable for non-invasive therapy monitoring in KTRs with HCV infection. Full article

Hepatitis C virus (HCV) is a hepatotropic virus that affects millions of human lives worldwide. Direct-acting antiviral (DAA) regimens are the most effective HCV treatment option. However, amino acid substitution-dependent resistance to DAAs has been a major challenge. This study aimed to determine the increasing risk of DAA resistance due to substitutions in DAA target non-structural proteins (NS3/4A, NS5A, and NS5B). Using a Sequence Retrieval System (SRS) at the virus pathogen resource (ViPR/BV-BRC), n = 32763 target protein sequences were retrieved and analyzed for resistance-associated amino acid substitutions (RAASs) by the Sequence Feature Variant Type (SFVT) antiviral-resistance assessment modeling tool. Reference target protein sequences with 100% identity were retried from UniProt following NCBI BLAST. The types and locations of RAASs were identified and visualized by AlphaFold and PyMol. Linux-r-base/R-studio was used for the data presentation. Multi-drug-resistant variants of NS3/4A in genotype 1 (n = 9) and genotype 5 (n = 5) along with DAA-specific NS3/4A, NS5A, and NS5B variants were identified pan-genotypically. A total of 27 variants (RAASs) of all the targets were identified. Fourteen genotype 1-specific substitutions: V1196A, V1158I, D1194A/T/G, R1181K, T1080S, Q1106R, V1062A, S1148G, A1182V, Y2065N, M2000T, and L2003V were identified. The most frequent substitutions were V1062L and L2003M, followed by Q2002H. L2003V, Q2002H, M2000T, Y2065N, and NL2003M of NS5A and L2003M of NS5B conferred resistance to daclatasvir. S2702T NS5B was the sofosbuvir-resistant variant. D1194A NS3/4A was triple DAA (simeprevir, faldaprevir, and asunaprevir) resistant. The double-drug resistant variants R1181K (faldaprevir and asunaprevir), A1182V and Q1106K/R (faldaprevir and simeprevir), T1080S (faldaprevir and telaprevir), and single drug-resistant variants V1062L (telaprevir), D1194E/T (simeprevir), D1194G (asunaprevir), S1148A/G (simeprevir), and Q1106L (Boceprevir) of NS3/4A were determined. The molecular phenomenon of DAA resistance is paramount in the development of HCV drug candidates. RAASs in NS3, NS5A, and NS5B reduce the susceptibility to DAAs; therefore, continuous RAAS-dependent resistance profiling in HCV is recommended to minimize the probability of DAA therapeutic failure. Full article

Aim and Objectives: Direct-acting antiviral (DAA) therapy can cure chronic hepatitis C (CHC), and daclatasvir (DCV)/asunaprevir (ASV) was the first interferon-free DAA therapy introduced in Korea. Patients who achieve sustained virologic response (SVR) after DAA treatment are expected to have good prognoses. Therefore, in this study, we aimed to investigate the prognosis of these patients. Materials and Methods: This multicenter prospective observational study included patients with CHC who achieved SVR after DCV/ASV treatment. The primary endpoint was hepatocellular carcinoma (HCC) occurrence, which was reviewed annually. Results: We included 302 patients (median follow-up duration: 38 [16.5–60.0] months; median age: 58 [49–67] years) in the study. Cirrhosis was observed in 103 patients (34.1%), and the median Child–Pugh score was 5.0. HCC occurred in 16 patients (5.3%) within six years post-SVR; these patients were older and had higher cirrhosis prevalence, alpha-fetoprotein levels, and fibrosis-4 index scores than did those without HCC development. Cox proportional hazards analysis revealed that age > 71 years (p = 0.005) and cirrhosis (p = 0.035) were significant risk factors for HCC occurrence. Conclusions: Although the prognoses of patients who achieved SVR with DCV/ASV therapy were generally good, the risk for HCC was present, especially in older patients and in those with cirrhosis. Hence, early treatment at younger ages and regular follow-up surveillance after achieving SVR are warranted. Full article

A significant number of deaths are reported annually worldwide due to microbial and viral infections. The development of protective medical textiles for patients and healthcare professionals has attracted many researchers’ attention. Therefore, this study aims to develop smart drug-eluting nanofibrous matrices to be used as a basic material for medical textile fabrication. First, chitosan/gelatin nanofibers were selected as the basic material owing to the wide antimicrobial activity of chitosan and the capability of gelatin to be hydrolyzed in the abundance of the papain-like protease (PLpro) enzyme secreted by SARS-CoV-2. Daclatasvir (DAC), an NS5A inhibitor, was selected as the model drug based on in silico studies where it showed high anti-SARS-CoV-2 potential compared to FDA-approved references. Due to their reported antimicrobial and antiviral activities, ZnO NPs were successfully prepared and incorporated with daclatasvir in chitosan/gelatin nanofibrous matrices through electrospinning. Afterward, an in vitro release study in a simulated buffer revealed the controlled release of DAC over 21 days from the nanofibers compared to only 6 h for free DAC. On the other hand, the abundance of PLpro induced the complete release of DAC from the nanofibers in only 4–8 h. Finally, the nanofibers demonstrated a wide antimicrobial activity against S. aureus, E. coli, and C. albicans. Full article

Daclatasvir dihydrochloride (DAC) is a drug used to treat hepatitis C virus (HCV) infection. In this study, an ionophore-based nanosphere emulsion was made of tricresyl phosphate (TCP) as the oil phase that is dispersed in water using Pluronic F-127 as an emulsifying agent. The nanospheres, consisting of the oil phase TCP, were doped with sodium tetraphenyl borate (Na-TPB) as a cation-exchanger and dibenzo-18-Crown-6 (DB18C6) as an ionophore (chelating agent) for DAC. The nanosphere emulsion was employed as a titrant in the complexometric titration of DAC (the analyte), and the DAC-selective electrode (ISE) was used as an indicator electrode to detect the endpoint. In the sample solution, DAC²⁺ ions diffused into the emulsified nanospheres, replaced Na⁺ from the ion exchanger (Na-TPB), and bonded to the ionophore (DB18C6). The DAC-selective nanospheres were successfully utilized to determine DAC in various samples, including standard solutions, commercial tablets (Daclavirocyrl^®), serum, and urine. The method exhibited a linear dynamic range of 81.18 µg/mL to 81.18 pg/mL (10⁻⁴ to 10⁻¹⁰ M), achieved high recovery values ranging from 99.4% to 106.5%, and displayed excellent selectivity over similar interfering species (sofosbuvir and ledipasvir). The proposed method offers a new approach to determine the drug species (neutral, anionic, and cationic) without the requirement of water-soluble ligands or pH control. Full article