Coxsackievirus A16 Research Articles

Течение энтеровирусной инфекции у детей в Краснодарском крае на современном этапе

Objective. To determine the clinical and epidemiologic features of the course of enterovirus infection (EVI) in Krasnodar Krai. Patients and methods. We analyzed the case histories of children who were treated in the State Budgetary Institution "SKDIB" of Krasnodar from January 2020 to November 2023. For the period from 01.01.2020 to 30.06.2022, out of 1560 patients with suspected acute infectious pathology, EVI was detected in 98 children, of whom boys accounted for 59.2% (n = 58), girls – 40.8% (n = 40). After removal of restrictions on new coronavirus infection from 01.07.2022 to November 2023, EVI was detected in 366 out of 2607 examined patients, of which boys accounted for 55.3% (n = 202), girls – 44.7% (n = 164). Most children (231, 63.1%) came from organized groups. In all forms of EVI, nasopharyngeal swabs, feces, and vesicle contents were examined by polymerase chain reaction; enterovirus RNA was detected in all patients. Molecular typing of enteroviruses was performed in the Federal Budgetary Institution "Center of Hygiene and Epidemiology in Krasnodar Krai". Results. It was revealed that exanthem and neurological forms prevailed during the given periods of observation.Of neurological lesions of EVI, enteroviral meningitis remains the leading form, which as an independent form occurred in 66.9% of cases, in combination with herpangina, exanthema, diarrhea – in 33.1%. The incidence rate of enteroviral meningitis for the period from 07.2022 to 11.2023 is 36.6%, the proportion of encephalitis increased to 2.7%. In the age structure of EVI cases for the period from 01.2020 to 06.2022, the main share was children aged 1 to 3 years old (42, 41.1%), for the period 07.2022–11.2023 – children from 4 to 6 years old (219, 59.9%). Conclusion. All age groups of children were involved in the epidemic process, but children aged 1 to 3 years (45.9%) and 7 to 14 years (22.4%) were sick more often, with the highest number of cases registered in preschool and school educational organizations. The greatest risk of developing severe forms of EVI is observed in children from risk groups. In recent years, there are still risks of epidemic rise in the incidence of exanthem and minor forms of EVI associated with the spread of Coxsackie A6, A16 and other viruses of the Coxsackie A and B species, the probability of spread of enterovirus A71 and possible resumption of circulation of EUNO 30 virus cannot be excluded. Key words: children, enterovirus infection, enteroviral exanthema, enteroviral meningitis, clinic

Analysis of miRNAs involved in mouse brain injury upon Coxsackievirus A6 infection.

Coxsackievirus A6 (CV-A6) has emerged as the predominant epidemic strain responsible for hand, foot and mouth disease (HFMD). CV-A6 infection can result in severe clinical manifestations, including encephalitis, meningitis, and potentially life-threatening central nervous system disorders. Our previous research findings demonstrated that neonatal mice infected with CV-A6 exhibited limb weakness, paralysis, and ultimately succumbed to death. However, the underlying mechanism of CV-A6-induced nervous system injury remains elusive. Numerous reports have highlighted the pivotal role of miRNAs in various viral infections. Separately established infection and control groups of mice were used to create miRNA profiles of the brain tissues before and after CV-A6 transfection, followed by experimental verification, prediction, and analysis of the results. At 2 days post-infection (dpi), 4 dpi, and 2dpi vs 4dpi, we identified 175, 198 and 78 significantly differentially expressed miRNAs respectively using qRT-PCR for validation purposes. Subsequently, we predicted target genes of these differentially expressed miRNAs and determined their potential targets through GO (Gene Ontology) enrichment analysis and KEGG (Kyoto Encyclopedia of Genes and Genomes) enrichment analysis. Finally, we verified the miRNA-mRNA pairing via double luciferase experiments while confirming functional enrichment of target genes through Western Blotting analyses. The results from this study suggest that transcriptional regulation, neuronal necrosis, pro-inflammatory cytokine release, and antiviral immunity are all implicated in the pathogenesis of central nervous system injury in mice infected with CV-A6. Brain injury resulting from CV-A6 infection may involve multiple pathways, including glial cell activation, neuronal necrosis, synaptic destruction, degenerative diseases of the nervous system. It can even encompass destruction of the blood-brain barrier, leading to central nervous system injury. The dysregulated miRNAs and signaling pathways discovered in this study provide valuable insights for further investigations into the pathogenesis of CV-A6.

Current Status of Research on Coxsackievirus A6 Hand, Foot and Mouth Disease

Current Status of Research on Coxsackievirus A6 Hand, Foot and Mouth Disease

Development and evaluation of a CRISPR-Cas13a system-based diagnostic for hepatitis E virus.

Hepatitis E virus (HEV) is the leading cause of acute viral hepatitis worldwide. HEV RNA detection is the goldstandard for HEV infection diagnosis and PCR methods are commonly used but are usually time-consuming and expensive, resulting in low detection efficiency and coverage, especially in low-income areas. Here, we developed a simpler and more accessible HEV RNA detection method based on CRISPR-Cas13a system. A total of 265 samples of different types and sources, including 89 positive samples and 176 negative samples, were enrolled for evaluations. The sensitivity andspecificity of the Cas13a-crRNA detection system were evaluated. The World Health Organization reference panel for HEV genotypes was used to evaluate the capability for detecting different HEV genotypes. The validity of the assay was compared with RT-qPCR. The 95 % limits of detection (LOD) of Cas13a-crRNA-based fluorescence assay and strip assay were 12.5 and 200 IU/mL, respectively. They did not show cross-reactivity with samples positive for hepatitis A virus, hepatitis B virus, hepatitis C virus, coxsackievirus A16, rotavirus, enterovirus 71, norovirus or enteropathic Escherichia coli. Different HEV genotypes (HEV1-4) can be detected by the assay. Compared to RT-qPCR, the positive predictive agreements of Cas13a-crRNA-based fluorescence and strip assay were 98.9 % (95 % CI: 93.9-99.8 %) and 91.0 % (95 % CI: 83.3-95.4 %), respectively. The negative predictive agreements were both 100 % (95 % CI: 97.8-100 %). In conclusion, we established a rapid and convenient HEV RNA detection method with good sensitivity and specificity based on CRISPR-Cas13a system, providing anew option for HEV infection diagnosis.

Antiviral Mechanisms of Saucerneol from Saururus chinensis against Enterovirus A71, Coxsackievirus A16, and Coxsackievirus B3: Role of Mitochondrial ROS and the STING/TKB-1/IRF3 Pathway.

Enterovirus A71 (EV71), coxsackievirus A16 (CVA16), and coxsackievirus B3 (CVB3) are pathogenic members of the Picornaviridae family that cause a range of diseases, including severe central nervous system complications, myocarditis, and pancreatitis. Despite the considerable public health impact of these viruses, no approved antiviral treatments are currently available. In the present study, we confirmed the potential of saucerneol, a compound derived from Saururus chinensis, as an antiviral agent against EV71, CVA16, and CVB3. In the in vivo model, saucerneol effectively suppressed CVB3 replication in the pancreas and alleviated virus-induced pancreatitis. The antiviral activity of saucerneol is associated with increased mitochondrial ROS (mROS) production. In vitro inhibition of mROS generation diminishes the antiviral efficacy of saucerneol. Moreover, saucerneol treatment enhanced the phosphorylation of STING, TBK-1, and IRF3 in EV71- and CVA16-infected cells, indicating that its antiviral effects were mediated through the STING/TBK-1/IRF3 antiviral pathway, which was activated by increased mROS production. Saucerneol is a promising natural antiviral agent against EV71, CVA16, and CVB3 and has potential against virus-induced pancreatitis and myocarditis. Further studies are required to assess its safety and efficacy, which is essential for the development of effective antiviral strategies against these viruses.

Metatranscriptomic data mining together with microfluidic card uncovered the potential pathogens and seasonal RNA viral ecology in a drinking water source.

Despite metatranscriptomics becoming an emerging tool for pathogen surveillance, very little is known about the feasibility of this approach for understanding the fate of human-derived pathogens in drinking water sources. We conducted multiplexed microfluidic cards and metatranscriptomic sequencing of the drinking water source in a border city of North Korea in four seasons. Microfluidic card detected norovirus, hepatitis B virus (HBV), enterovirus, and Vibrio cholerae in the water. Phylogenetic analyses showed that environmental-derived sequences from norovirus GII.17, genotype C of HBV, and coxsackievirus A6 (CA6) were genetically related to the local clinical isolates. Meanwhile, metatranscriptomic assembly suggested that several bacterial pathogens, including Acinetobacter johnsonii and V. cholerae might be prevalent in the studied region. Metatranscriptomic analysis recovered 349 species-level groups with substantial viral diversity without detection of norovirus, HBV, and CA6. Seasonally distinct virus communities were also found. Specifically, 126, 73, 126, and 457 types of viruses were identified in spring, summer, autumn, and winter, respectively. The viromes were dominated by the Pisuviricota phylum, including members from Marnaviridae, Dicistroviridae, Luteoviridae, Potyviridae, Picornaviridae, Astroviridae, and Picobirnaviridae families. Further phylogenetic analyses of RNA (Ribonucleic Acid)-dependent RNA polymerase (RdRp) sequences showed a diverse set of picorna-like viruses associated with shellfish, of which several novel picorna-like viruses were also identified. Additionally, potential animal pathogens, including infectious bronchitis virus, Bat dicibavirus, Bat nodavirus, Bat picornavirus 2, infectious bursal disease virus, and Macrobrachium rosenbergii nodavirus were also identified. Our data illustrate the divergence between microfluidic cards and metatranscriptomics, highlighting that the combination of both methods facilitates the source tracking of human viruses in challenging settings without sufficient clinical surveillance.

Synergetic association between coxsackievirus A16 genotype evolution and recombinant form shifts.

Coxsackievirus A16 (CVA16) is a major pathogen that causes hand, foot, and mouth disease (HFMD). The recombination form (RF) shifts and global transmission dynamics of CVA16 remain unknown. In this retrospective study, global sequences of CVA16 were retrieved from the GenBank database and analyzed using comprehensive phylogenetic inference, RF surveys, and population structure. A total of 1,663 sequences were collected, forming a 442-sequences dataset for VP1 coding region analysis and a 345-sequences dataset for RF identification. Based on the VP1 coding region used for serotyping, three genotypes (A, B, and D), two subgenotypes of genotype B (B1 and B2), and three clusters of subgenotype B1 (B1a, B1b, and B1c) were identified. Cluster B1b has dominated the global epidemics, B2 disappeared in 2000, and D is an emerging genotype dating back to August 2002. Globally, four oscillation phases of CVA16 evolution, with a peak in 2013, and three migration pathways were identified. Europe, China, and Japan have served as the seeds for the global transmission of CVA16. Based on the 3D coding region of the RFs, five clusters of RFs (RF-A to -E) were identified. The shift in RFs from RF-B and RF-C to RF-D was accompanied by a change in genotype from B2 to B1a and B1c and then to B1b. In conclusion, the evolution and population dynamics of CVA16, especially the coevolution of 3D and VP1 genes, revealed that genotype evolution and RF replacement were synergistic rather than stochastic.

Emerging concerns of atypical hand foot and mouth disease caused by recombinant Coxsackievirus A6 variants in Henan, China.

An increasing number of studies have reported that atypical hand, foot, and mouth disease (HFMD) is becoming a new concern for children's health. At present, there is no official definition for atypical HFMD, but some studies have defined that it occurs at anatomic sites not listed in the definition of HFMD issued by the World Health Organization. Several pathogens have been reported to cause atypical HFMD, such as Coxsackievirus (CV)A6. As one of the most prevalent enteroviruses in the world, CVA6 seems to affect a wider range of children and causes more severe and prolonged illness than other enteroviruses. The early lesions of atypical HFMD are very similar to the clinical presentations of other diseases, such as eczema, which poses a challenge for clinicians aiming to identify and diagnose HFMD in a timely manner. Here, we report on six atypical HFMD patients caused by recombinant CVA6 variants, and the atypical manifestations include eczema coxsackium, large herpes, rice-like red papules and herpes, purpuric rash, and onychomadesis, as well as and large red herpes on scalp, perianal, testicles, shoulders and neck, and other atypical eruption sites, hoping to draw the attention of other pediatricians. This study will provide scientific guidance for timely diagnosis of HFMD to prevent serious complications.

Circulating trends of hand, foot, and mouth disease in Hubei Province, China: Impact from the COVID-19 pandemic

ObjectivesThis study was performed to investigate the effect of non-pharmaceutical interventions on hand, foot, and mouth disease in Hubei Province China during the coronavirus disease 2019 pandemic. MethodsData and samples were collected from the hand, foot, and mouth disease surveillance laboratory network in Hubei Province between 2018 and 2022. The samples were identified as Enterovirus A71, Coxsackievirus A6or Coxsackievirus A16 via real-time polymerase chain reaction. Representative Coxsackievirus A6 and Coxsackievirus A16 samples were sequenced and subjected to phylogenetic analyses. ResultsA noticeable 3-fold reduction in the number of hand, foot, and mouth disease cases was observed from 2019 to 2020. The age and sex distributions of patients with hand, foot, and mouth disease were approximately the same from 2018 to 2022. The proportion of Coxsackievirus A6 accounted for 86 % in 2020 and 75 % in 2021 for hand, foot, and mouth disease compared with 48 % in 2018, 53 % in 2019, and 29 % in 2022. The proportions of Coxsackievirus A16 in 2020 and 2021 were 2 % and 17 %, respectively, showing a sharp decline in 2018 (37.8 %) and 2019 (35 %). In 2022, Coxsackievirus A16 was the dominant serotype (46 %). Only slight differences were found in the VP1 sequences across the different years. ConclusionsOur study confirmed that a series of non-pharmaceutical interventions during the coronavirus disease 2019 period reduced the transmission of enteroviruses and that long-term restrictions could significantly change the prevalence of enterovirus serotypes causing hand, foot, and mouth disease.

Molecular Epidemiology and Evolution of Coxsackievirus A14.

As the proportion of non-enterovirus 71 and non-coxsackievirus A16 which proportion of composition in the hand, foot, and mouth pathogenic spectrum gradually increases worldwide, the attention paid to other enteroviruses has increased. As a member of the species enterovirus A, coxsackievirus A14 (CVA14) has been epidemic around the world until now since it has been isolated. However, studies on CVA14 are poor and the effective population size, evolutionary dynamics, and recombination patterns of CVA14 are not well understood. In this study, 15 CVA14 strains were isolated from HFMD patients in mainland China from 2009 to 2019, and the complete sequences of CVA14 in GenBank as research objects were analyzed. CVA14 was divided into seven genotypes A-G based on an average nucleotide difference of the full-length VP1 coding region of more than 15%. Compared with the CVA14 prototype strain, the 15 CVA14 strains showed 84.0-84.7% nucleotide identity in the complete genome and 96.9-97.6% amino acid identity in the encoding region. Phylodynamic analysis based on 15 CVA14 strains and 22 full-length VP1 sequences in GenBank showed a mean substitution rate of 5.35 × 10-3 substitutions/site/year (95% HPD: 4.03-6.89 × 10-3) and the most recent common ancestor (tMRCA) of CVA14 dates back to 1942 (95% HPD: 1930-1950). The Bayesian skyline showed that the effective population size had experienced a decrease-increase-decrease fluctuation since 2004. The phylogeographic analysis indicated two and three possible migration paths in the world and mainland China, respectively. Four recombination patterns with others of species enterovirus A were observed in 15 CVA14 strains, among which coxsackievirus A2 (CVA2), coxsackievirus A4 (CVA4), coxsackievirus A6 (CVA6), coxsackievirus A8 (CVA8), and coxsackievirus A12 (CVA12) may act as recombinant donors in multiple regions. This study has filled the gap in the molecular epidemiological characteristics of CVA14, enriched the global CVA14 sequence database, and laid the epidemiological foundation for the future study of CVA14 worldwide.

An update on Tomato Flu Virus: A Mini-review

Abstract:This article aims to highlight the most recent information on the “tomato flu” epidemic in India. A new disease has sprung out in several areas of India. The illness had a rash that was predominantly seen in children under the age of five and was highly infectious. It was known as “tomato flu” because the rash was excruciatingly painful, and the blisters were the size of tiny tomatoes. None of the afflicted children experienced problems that would have resulted in death. The focus of the therapy was primarily symptomatic, supportive care along with isolation and sustaining hygiene standards. The RNA virus Coxsackievirus A16, a member of the Picornaviridae family, was shown to be the cause of this disease. A detailed literature review was performed on the epidemiology, aetiology, evolution, transmission, outbreak, preventive measures and management and treatment of tomato flu. The leading prevention is preventing infected children and infants from sharing clothes, food, and toys. Few drugs are used to prevent fever, but no antiviral drugs or vaccines are available to prevent tomato fever. We came to the conclusion that a novel form of Coxsackievirus A16 may be responsible for the current pandemic of this disease in India.

Analysis of coxsackievirus A6 circulation in the territories of the Far Eastern Federal district of the Russian Federation in 2014–2019

Introduction. Molecular epidemiological monitoring of enterovirus infection (EVI) in the territories of the Russian Federation showed that coxsackievirus A6 (CVA-6) had been one of the most prevalent types of enteroviruses that circulated among the country population during last years and had caused majority of EVI outbreaks.
 Objective — to evaluate coxsackievirus A6 circulation in the territories of the Far Eastern Federal district (FEFD) in 2014–2019 utilizing methods of molecular genetics.
 Materials and methods. RT-PCR was employed to detect enterovirus RNA in biological material collected in 9 territories of the FEFD . In order to establish enterovirus types, amplification of positive samples was carried out to detect nucleotide sequence fragments of the VP1 and VP2 genes. Molecular genetic analysis of the Far Eastern CVA-6 strains was based on detection of nucleotide sequences of VP1 and 3Dpol gene fragments. Phylogenetic trees were constructed by the means of Bayesian phylogenetic methods.
 Results. Total 1773 nucleotide sequences of 43 types of non-polio enteroviruses were obtained in 2014-2019. Majority of the sequences belonged to coxsackievirus A6 (524; 29.5%). In the years of the highest CVA-6 detection an increase in EVI incidence as well as EVI outbreaks were observed in the territories of FEFD. The most prevalent manifestations of EVI caused by CVA-6 in FEFD were herpangina and exanthemic forms. Phylogenetic analysis showed that Far Eastern strains of CVA-6 during in the analyzed period of time belonged to D3 subgenotype that is dominant in the world. The circulation of several recombinant forms of CVA-6 (RF-A, -H, -L, -N, -R) was also registered.
 Conclusion. The genetic diversity of CVA-6 strains circulating in the territories of the FEFD in 2014–2019 revealed in this study requires further investigation in order to obtain new knowledge about the CVA-6 molecular epidemiology and improve the enterovirus surveillance system.

Non-polio enteroviruses circulation in acute flaccid paralysis cases and sewage in Senegal from 2013 to 2021

ObjectivesSeveral factors can cause acute flaccid paralysis cases including non-polio enteroviruses. In Senegal, few studies on non-polio enteroviruses (NPEV) have been performed. MethodsOur study assess the molecular epidemiology of non-polio enteroviruses in Senegal from 2013 to 2021 through the previously existing programs for surveillance of polioviruses. ResultsA total of 3815 stool samples and 281 sewage samples were collected. After virus isolation by cell culture, non-polio enteroviruses-positive isolates were confirmed by reverse transcriptase-quantitative polymerase chain reaction. Following this detection, the positive samples were subjected to molecular characterization. Our data showed that 15.22% and 52.66% were positive in cell culture for non-polio enteroviruses in acute flaccid paralysis surveillance and environmental surveillance, respectively. These non-polio enteroviruses-positive isolates were detected all year round but tend to unequal peaks of circulation, and the age group 0-5 years was more vulnerable to infection (84.4%). Genetic characterization revealed the circulation of enteroviruses species infecting humans (Enterovirus A – Enterovirus D): Enterovirus A (29.2%) and Enterovirus B (63.1%) isolates from both the acute flaccid paralysis surveillance and environmental surveillance while Enterovirus C (5.3%) and Enterovirus D (2.4%) were only isolated from the acute flaccid paralysis surveillance. However, the highly prevalent Enterovirus B species from the acute flaccid paralysis surveillance included echovirus 7 and echovirus 13, whereas coxsackievirus A6 was the predominant species from the environmental surveillance. ConclusionThis first 8-year period study of NPEV in Senegal showed that NPEV represent important viral etiologies associated with acute flaccid paralysis cases and circulating in environmental surveillance in Senegal and highlighted the need to promote effective long-term strategies for monitoring of non-polio enteroviruses infections.

Coxsackievirus A6 pneumonia in a child

Coxsackievirus A6 pneumonia in a child

Effects of glycine 64 substitutions in RNA-dependent RNA polymerase on ribavirin sensitivity and pathogenicity of coxsackievirus A6

Hand, foot, and mouth disease (HFMD) caused by a group of enteroviruses is a global public health problem. In recent years, coxsackievirus A6 (CVA6) has emerged as an important HFMD agent. Previous studies have shown that mutations of glycine 64 in RNA-dependent RNA polymerase (3D polymerase), which is central to viral replication, cause phenotypic changes such as ribavirin resistance, increased replication fidelity, and virulence attenuation in poliovirus and enterovirus A71. In this study, we constructed CVA6 mutants with G64R, G64S, and G64T substitutions by site-directed mutagenesis in full-length cDNA of an infectious CVA6 strain cloned in pcDNA3.1. Viral RNA was obtained by in vitro transcription, and the rescued virus strains were propagated in RD cells. Sequencing after six passages revealed that G64S and G64T mutations were stably inherited, whereas G64R was genetically unstable and reversed to the wild type. Comparison of the biological characteristics of the wild-type and mutant CVA6 strains in an in vivo model (one-day-old ICR mice) revealed that the pathogenicity of CVA6-G64S and CVA6-G64T was significantly reduced compared to wild-type CVA6. In vitro experiments indicated the mutant CVA6-G64S and CVA6-G64T strains had increased resistance to 0.8 mM ribavirin and a decreased replication rate in the presence of 0.8 mM guanidine hydrochloride. Our results show that mutation of residue 64 reduces CVA6 susceptibility to ribavirin and increases CVA6 susceptibility to guanidine hydrochloride, together with increased replication fidelity and attenuated viral pathogenicity, thus laying a foundation for the development of safe and effective live attenuated CVA6 vaccine.

Preparation and immunoprotective effects of a virus-like particle candidate vaccine of the dominant epidemic D3 genotype coxsackievirus A6 in China

Coxsackievirus A6 of the D3a genotype (CVA6 D3a) is a primary pathogen causingmainland of China's hand, foot, and mouth disease (HFMD). Viral-like particle (VLP) vaccines represent a potential candidate vaccine to prevent HFMD. This study collected Anti-CVA6 D3a VLPs serum from BALB/c female mice immunized using CVA6 D3a VLPs. The neutralizing antibody levels were compared against the representative 14-JX2018 (D3a) and N4-YN2015 (D3b) strains between the antisera of different immune pathways. The immunoprotective effect of anti-CVA6 D3a VLPs against these strains was monitored using pathological sections and immunohistochemical results of lung and skeletal muscle tissues in seven-day-old Institute of Cancer Research (ICR) mice. Immunological protection against different branches of viruses was evaluated in 7-day-old (serum passive immune protection) and 14-day-old (VLPs active immune protection) neonatal ICR mice models. Serum-neutralizing antibody levels were positively correlated with the number of immunizations and higher against 14-JX2018 than against N4-YN2015. Furthermore, these levels were significantly higher with abdominal injection than intramuscular injection. The immunized serum of 7-day-old ICR mice inoculated three times was 100 % protected against CVA6 D3a 14-JX2018 (lethal titer: 106.25 TCID50) and CVA6 D3b N4-YN2015 (lethal titer: 105.25TCID50) fatal attacks, respectively. For ICR mice that have completed two active immunizations for 14 days, both CVA6 D3a 14-JX2015 (challenge titer: 108.25 TCID50) and CVA6 D3b N4-YN2015 (challenge titer: 107.25 TCID50) were used for the challenge, and the mice were able to survive. Overall, the CVA6 D3a VLPs prepared in this study are a potential vaccine candidate for CVA6, as it has the optimal protective effect against both CVA6 D3a and D3b evolutionary branches viruses.

Enterovirus Coxsackie A16 Detected in Hand, Foot, and Mouth Disease Outbreak Among Children in Western Uttar Pradesh, India, May to June 2022.

Enterovirus Coxsackie A16 Detected in Hand, Foot, and Mouth Disease Outbreak Among Children in Western Uttar Pradesh, India, May to June 2022.

Identifying potential compounds from Bacopa monnieri (brahmi) against coxsackievirus A16 RdRp targeting HFM disease (tomato flu)

Hand, foot, and mouth disease (HFMD), primarily instigated by Coxsackievirus A16 (CVA16), poses a serious health concern, necessitating effective therapeutic interventions. The RNA-dependent RNA polymerase (RdRp) of CVA16 emerges as a promising drug target for HFMD treatment. This study presents an in-silico pipeline for the identification of potential RdRp inhibitors against CVA16. A library of 91 natural compounds derived from Bacopa monnieri (brahmi) was virtually screened against the CVA16 RdRp. Here, Bacobitacin D emerged as a promising hit molecule, forming 8 hydrogen bonds including key catalytic site residues (Asp238 and Asp329) within the RdRp active site. Further, molecular dynamics (MD) simulations and MM/GBSA binding free energy calculations was applied on the top three hits that were selected based on exhaustive docking scores (≤−9.55 ​kcal/mol). Bacobitacin D exhibited sustainable stability, as evidenced by minimal deviation (RMSD ​= ​0.75 ​± ​0.02 ​nm) during a 100 ns MD simulation. Importantly, Bacopaside IV exhibited the lowest ΔGTOTAL binding free energy (−23.70 ​kcal/mol), while Bacobitacin D displayed a comparable ΔGTOTAL of −19.14 ​kcal/mol. Structural interpretation of the most populated cluster derived from MD simulations showed direct interactions of Bacobitacin D with pivotal catalytic residues, including Asp238 and Ser289. This comprehensive study confirmed Bacobitacin D as a potent inhibitor of CVA16 RdRp, offering a potential avenue for therapeutic intervention against HFMD. Experimental validation is required to confirm the inhibitory action of Bacobitacin D against HFMD.

Hand, Foot, and Mouth Disease Outbreak What You Need to Know.

HFMD is an obvious disease in children mostly below the age of five constituting a public health challenge to Asian-Pacific and developing countries majorly. This disease is often caused by enterovirus 71 (EV71) and Coxsackievirus A16. HFMD is a mild degree fever and general illness which manifests for about 10 days. Young age, male gender, poor hygiene, and high social contacts are some risk factors. HFMD can be diagnosed clinically by isolating the virus from stool and pharynx and identifying it on Light microscopic examination. Polymerase Chain Reaction Assay is a gold standard for confirming the virus from swabbed lesions. Late confirmation could lead to severe complications. There are no specific treatments and vaccines licensed for general use in the treatment of various serotypes of HFMD. The major strategy to prevent and control this disease is to strictly follow the WHO 8 guidelines to curb the spread of the disease.

Whole-genome sequencing and phylogenetic analysis of coxsackievirus-A16 strains causing hand, foot and mouth disease (HFMD) in India.

Hand, foot and mouth disease (HFMD) is a common childhood infectious disease, caused by enteroviruses (EVs), which can present with typical or atypical lesions. The illness is self-limiting, but it can also have serious complications. Since 1997, HFMD infections have become endemic and have increased to epidemic proportions across the Asia Pacific region, including India. Coxsackievirus-A16 (CV-A16) outbreaks occurred in India from 2005 onwards, although the clinical symptoms were noticeably different during this period. Understanding the population dynamics of enteroviruses that cause HFMD is crucial in the post-polio era because one of the circulating strain may replace another as the dominant strain. The aim of this study is to describe the genetic features of the CV-A16 strains isolated from hand, foot and mouth disease (HFMD) patients in India. Reverse transcription PCR (RT-PCR) and cell-culture-based isolation of CV-A16 was done from the 55 clinical samples. The entire genome of the CV-A16 isolate was performed from the seven isolates. After the sequences were analysed, a phylogenetic tree was created using bioinformatics tools. The total genomic length obtained was 7411 base pairs (bp). Nucleotide similarity across various regions, including 5'UTR, P1, P2 and 3'UTR, ranged from 87.0-97.9 %, 77.0-95.4 %, 80.3-96.9 %, and 77.9-96.2 %, respectively. Correspondingly, similarities in the VP1 region's nucleotide and amino acid sequences were 91.4-96.4 % and 99.3-99.7 %, respectively. Phylogenetic analysis highlighted that CV-A16 strains identified in Pune, Maharashtra, were grouped within the same cluster. The analysed CV-A16 isolates in this study aligned with subgenotype B1c. These findings have far-reaching implications for the surveillance, prevention and management of HFMD and CV-A16. Monitoring the dynamics of CV-A16 strains, informed by the genetic characteristics identified here, will significantly impact strategies aimed at tackling HFMD and its associated public health challenges.