Virus Strains Research Articles

Genetic Characterization, Pathogenicity, and Epidemiology Analysis of Three Sub-Genotype Pigeon Newcastle Disease Virus Strains in China.

Pigeon Newcastle disease (ND) is a serious infectious illness caused by the pigeon Newcastle disease virus (NDV) or Paramyxovirus type 1 (PPMV-1). Genotype VI NDV is a primary factor in ND among Columbiformes (such as pigeons and doves). In a recent study, eight pigeon NDV strains were discovered in various provinces in China. These viruses exhibited mesogenic characteristics based on their MDT and ICPI values. The complete genome sequences of these eight strains showed a 90.40% to 99.19% identity match with reference strains of genotype VI, and a 77.86% to 80.45% identity match with the genotype II vaccine strain. Additionally, analysis of the F gene sequence revealed that these NDV strains were closely associated with sub-genotypes VI.2.2.2, VI.2.1.1.2.1, and VI.2.1.1.2.2. The amino acid sequence at the cleavage site of the F protein indicated virulent characteristics, with the sequences 112KRQKRF117 and 112RRQKRF117 observed. Pigeons infected with these sub-genotype strains had a low survival rate of only 20% to 30%, along with lesions in multiple tissues, highlighting the strong spread and high pathogenicity of these pigeon NDV strains. Molecular epidemiology data from the GenBank database revealed that sub-genotype VI.2.1.1.2.2 strains have been prevalent since 2011. In summary, the findings demonstrate that the prevalence of genotype VI NDV is due to strains from diverse sub-genotypes, with the sub-genotype VI.2.1.1.2.2 strain emerging as the current epidemic strain, highlighting the significance of monitoring pigeon NDV in China.

Registration of ‘CP 13‐1954’ sugarcane for Florida organic soils

Abstract‘CP 13‐1954’ (Reg. no. CV‐218, PI 704104) sugarcane (Saccharum spp. hybrid) was developed through cooperative research conducted by the USDA–ARS, the University of Florida, and the Florida Sugar Cane League, Inc., and released to growers for organic (muck) soils in Florida in June 2020. The parentage of CP 13‐1954 is ‘CP 85‐1491’ × Poly 09‐24. Based on the results of three crops (plant cane, first ratoon, and second ratoon) in field trials conducted at five locations, CP 13‐1954 had higher cane yield (16.2%), sucrose yield (15.6%), and economic index (29.7%) at P < .05 compared with the reference cultivar, ‘CP 96‐1252’. CP 13‐1954 stalks are usually taller than the reference cultivar, ‘CP 00‐1101’, with small‐to‐medium diameter, and exhibits resistance to ratoon stunting disease, Sugarcane mosaic virus strain E, brown rust, orange rust, and smut and moderate resistance to leaf scald on muck soils in Florida. CP 13‐1954 has Bru1 locus that provides resistance against brown rust. CP 13‐1954 showed moderate cold tolerance among all the tested cultivars.

Beyond bNAbs: Uses, Risks, and Opportunities for Therapeutic Application of Non-Neutralising Antibodies in Viral Infection.

The vast majority of antibodies generated against a virus will be non-neutralising. However, this does not denote an absence of protective capacity. Yet, within the field, there is typically a large focus on antibodies capable of directly blocking infection (neutralising antibodies, NAbs) of either specific viral strains or multiple viral strains (broadly-neutralising antibodies, bNAbs). More recently, a focus on non-neutralising antibodies (nNAbs), or neutralisation-independent effects of NAbs, has emerged. These can have additive effects on protection or, in some cases, be a major correlate of protection. As their name suggests, nNAbs do not directly neutralise infection but instead, through their Fc domains, may mediate interaction with other immune effectors to induce clearance of viral particles or virally infected cells. nNAbs may also interrupt viral replication within infected cells. Developing technologies of antibody modification and functionalisation may lead to innovative biologics that harness the activities of nNAbs for antiviral prophylaxis and therapeutics. In this review, we discuss specific examples of nNAb actions in viral infections where they have known importance. We also discuss the potential detrimental effects of such responses. Finally, we explore new technologies for nNAb functionalisation to increase efficacy or introduce favourable characteristics for their therapeutic applications.

2024 Updates to Cervical Cancer Screening in Canada

The landscape of cervical cancer screening in Canada is about to undergo a major shift from cytology-based screening to testing directly for the presence of high-risk strains of the human papilloma virus (HPV), the persistence of which is known to be a prerequisite for the development of almost all cases of cervical cancer. In 2018, the World Health Organization declared a call to action for the worldwide elimination of cervical cancer by 2040. Subsequently the Canadian Partnership Against Cancer (CPAC) released an action plan outlining the necessary steps for Canada to reach this goal. One of the 3 major priorities identified in the action plan is the transition to primary HPV testing. This transition from screening to testing represents a major shift in infrastructure and also a shift in mindset for clinicians, policymakers, and the public. To help guide this transition, CPAC has collaborated with the Gynecologic Oncology Society of Canada (GOC) and the Society of Canadian Colposcopists (SCC) to release two open-access, evidence‑based guidelines in June 2023. These guidelines address how to manage a positive HPV screening test, and colposcopy in the context of primary HPV‑screening. This paper will outline the evolution of cervical cancer screening in Canada along with the rationale behind the transition to HPV testing. Also included is a discussion on the broad recommendations from the 2023 CPAC/GOC/SCC guidelines, as well as recommendations for age and interval of screening and special populations. Readers of this article in e-journal format can access the Canadian Guideline on the Management of a Positive Human Papillomavirus Test and Guidance for Specific Populations here. Readers may also access the 2023 Canadian Colposcopy Guideline: A Risk-Based Approach to Management and Surveillance of Cervical Dysplasia here.

Electron Microscopic and Histopathological Studies of the First Viral Infection Reported in <i>Ipomoea Cairica</i> (L.) Sweet

Viral infections pose significant threats to plant health, impacting agriculture and medicinal plant production. This study focuses on diagnosing viral infections in <i>Ipomoea cairica</i> (L.) Sweet using advanced techniques such as Transmission Electron Microscopy (TEM) and Microtomy. Phenotypic symptoms, anatomical changes, and the confirmation of Gemini virus through TEM are investigated. Transmission studies reveal multiple vectors, including <i>Bemisia tabaci</i>, highlighting the importance of understanding viral spread mechanisms. Host range studies demonstrate widespread susceptibility among various plant families. The research emphasizes early diagnosis and management to mitigate economic losses and preserve medicinal metabolites. Future efforts will employ PCR and DNA sequencing for precise viral strain identification and targeted management strategies. The findings underscore the importance of early diagnosis and management of viral infections to safeguard plant health and preserve essential metabolites. Future research aims to utilize PCR and DNA sequencing for precise identification and targeted management of viral strains, enabling effective disease control strategies for <i>Ipomoea cairica</i> (L.) Sweet and similar plant species. This study underscores the necessity for proactive measures to protect plant species like <i>Ipomoea cairica</i> (L.) Sweet from viral infections, ensuring sustainable agriculture and medicinal plant production.

Covid-19 Study, Diagnostic and Therapeutic Transition.

The outbreak of coronavirus (severe acute respiratory syndrome coronavirus2, COVID-19, SARS-Co-2) in Wuhan, China occurred three years ago. However, the healthcare state and legislature for Covid-19 varied greatly worldwide. After three years, the social life of most countries worldwide is gradually back to normal. Diagnosis and therapeutics worldwide are formalized now. Improvement of the knowledge about this devastating disease will shed new light on its management and spawn the development of new counter measures. Due to the differences in socioeconomic conditions and policies worldwide, the diagnostic and therapeutic transition should be established. The schedules and techniques of vaccines, drugs, or other therapeutic strategies could be formalized in the future. The origin and hidden nature of Covid-19 biology (relationship between viral strain and drug targeting) should be further investigated. Knowledge and opinion breakthroughs may significantly heighten the quality of preventive and therapeutic strategies against Covid-19. To further stabilize the global situation, the issues of viral spread and induced mortality should be emphasized. Existing animal models, pathophysiological knowledge, and therapeutics for different infected patients played vital roles. The diagnostic widening, variants of COVID, and therapeutic selection worldwide totally solve the complex outcomes and promote the curability for infected patients. Different diagnostic platforms can reach different therapeutic selections, responses, and benefits in the clinic. It will provide advanced diagnostic dimensions, therapeutic paradigms, and drug selection strategies for the purpose of the greatest benefiting and recoveries of Covid-19 patients. To speed up the global fight against Covid-19, biomedical knowledge, prophylactic vaccines, and therapeutic paradigms should be updated in dynamic states.

Monitoring the sensitivity of influenza viruses to oseltamivir, in Romania, from 2016 to 2023

Abstract Introduction: influenza is an acute viral disease caused by infection of the upper respiratory tract - difficult to control, which affects a large part of the population. Neuraminidase inhibitors (NAIs), such as oseltamivir and zanamivir, are the antiviral drugs utilized in Romania for the treatment of respiratory infections caused by the influenza viruses. The objective of the study is to monitor and analyze influenza viruses circulating in Romania, in terms of their susceptibility to oseltamivir, with the aim of signalling the emergence of viral strains resistant to antivirals. Methods: The phenotypic method was performed to evaluate the inhibitory effect of oseltamivir on the neuraminidase enzyme activity of influenza viruses. Genotypic methods (SNP-based assays or sequencing of neuraminidase/whole genome) were used for detecting amino acid substitutions associated with influenza antiviral resistance. The study period is from 2016 to 2023. Results: from the total number of influenza viruses isolated during the period (833 isolated), 670 strains were characterized antigenically and genetically, and the phenotypic susceptibility to antivirals was performed for 245 isolated viral strains. According to WHO criteria categories antiviral susceptibility based on IC50 data, none of the test results indicated reduced or highly reduced inhibition by oseltamivir. Conclusion: This monitoring, carried out in the National Influenza Center Romania - Cantacuzino NMMIRD, is extremely important to maintain effective flu control and further development of other antiviral agents.

Identification of Garlic Viruses Associated with Seed Bulbs and Consumption Bulbs from Several Locations in Indonesia

Virus infection is one of the major constraints in garlic production since the viruses are readily accumulated on vegetative propagation material (bulbs). This research aimed to detect garlic common latent virus (GCLV), shallot latent virus (SLV), onion yellow dwarf virus (OYDV), and leek yellow stripe virus (LYSV) infecting local garlic as seed bulb and imported garlic as consumption bulb. Seed bulb samples were obtained from seed breeders in several garlic growing centers in Indonesia. In contrast, consumption bulb samples were obtained from plant quarantine warehouses and three local markets in Bogor. Some bulb samples were used for morphological observations, and some were germinated in the laboratory until the leaves emerged. Leaves were collected for virus detection by RT-PCR using specific primers for GCLV, SLV, OYDV, and LYSV. Seed and consumption bulbs have differences in their morphological characteristics, especially in the type of neck hardness and the size of the bulb diameter. OYDV and LYSV infections were successfully detected in seed and consumption bulbs, while SLV was only found in consumption bulbs. Nucleotide sequence analysis showed that SLV from consumption bulbs formed one group, GCLV from seed bulbs formed one group, while OYDV and LYSV from seed and consumption bulbs were in different groups, indicating that the viruses came from different strains. Further research through high-throughput detection methods and providing virus-free planting material are needed to anticipate the spread of new strains of garlic viruses in Indonesia.

Detection and Phylogenetic Analysis of Orf Virus and Muskox Rhadinovirus 1 from Muskoxen (Ovibos moschatus) in the Canadian Arctic.

Orf virus (genus Parapoxvirus) has been associated with gross skin lesions on muskoxen (Ovibos moschatus) from Victoria Island, Nunavut, Canada, where muskox populations are experiencing population declines. Orf virus causes painful proliferative and necrotizing dermatitis upon viral replication and shedding, which may lead to animal morbidity or mortality through secondary infections and starvation. Herpesvirus, known to cause gross lesions on skin and mucosa during active viral replication, has also been documented in muskoxen but to date has not been associated with clinical disease. Our objective was to characterize the variation of orf virus and herpesvirus in wild muskoxen of the Canadian Arctic. Tissue samples including gross skin lesions from the nose, lips, and/or legs were opportunistically collected from muskoxen on Victoria Island, Nunavut and Northwest Territories, and mainland Nunavut, Canada, from 2015 to 2017. Sampled muskoxen varied in age, sex, location, hunt type, and body condition. Tissues from 60 muskoxen were tested for genetic evidence of orf virus and herpesvirus infection using PCR targeting key viral genes. Tissues from 38 muskoxen, including 15 with gross lesions, were also examined for histological evidence of orf virus and herpesvirus infection. Eleven muskoxen (10 from Victoria Island and one from mainland Nunavut) with gross lesions had microscopic lesions consistent with orf virus infection. Muskox rhadinovirus 1, a gammaherpesvirus endemic to muskoxen, was detected in 33 (55%) muskoxen including 17 with gross lesions. In all tissues examined, there was no histological evidence of herpesvirus-specific disease. Sequencing and characterization of amplified PCR products using phylogenetic analysis indicated that a strain of orf virus, which appears to be unique, is likely to be endemic in muskoxen from Victoria Island and mainland Nunavut. Many of the muskoxen are also subclinically infected with a known muskox-endemic strain of herpesvirus.

Rapid molecular epidemiology investigations into two recent measles outbreaks in Israel detected from October 2023 to January 2024.

Between late 2023 and early 2024, two measles outbreaks occurred in Israel, each caused by importation of measles virus strains of respective B3 and D8 genotypes. In this study, we validate transmission pathways uncovered by epidemiological investigations using a rapid molecular approach, based on complete measles virus genomes. The presented findings support this rapid molecular approach in complementing conventional contact tracing and highlight its potential for informing public health interventions.

Nanoformulation of the Broad-Spectrum Hydrophobic Antiviral Vacuolar ATPase Inhibitor Diphyllin in Human Recombinant H-ferritin.

As highlighted by recent pandemic outbreaks, antiviral drugs are crucial resources in the global battle against viral diseases. Unfortunately, most antiviral drugs are characterized by a plethora of side effects and low efficiency/poor bioavailability owing to their insolubility. This also applies to the arylnaphthalide lignin family member, diphyllin (Diph). Diph acts as a vacuolar ATPase inhibitor and has been previously identified as a promising candidate with broad-spectrum antiviral activity. However, its physicochemical properties preclude its efficient administration in vivo, complicating preclinical testing. We produced human recombinant H- ferritin (HsaFtH) and used it as a delivery vehicle for Diph encapsulation through pH-mediated reversible reassembly of HsaFtH. Diph nanoformulation was subsequently thoroughly characterized and tested for its non-target cytotoxicity and antiviral efficiency using a panel of pathogenic viral strain. We revealed that loading into HsaFtH decreased the undesired cytotoxicity of Diph in mammalian host cells. We also confirmed that encapsulated Diph exhibited slightly lower antiviral activity than free Diph, which may be due to the differential uptake mechanism and kinetics of free Diph and Diph@HsaFtH. Furthermore, we confirmed that the antiviral effect was mediated solely by Diph with no contribution from HsaFtH. It was confirmed that HsaFtH is a suitable vehicle that allows easy loading of Diph and production of highly homogeneous nanoparticles dispersion with promising broad-spectrum antiviral activity.

186 Outbreak of Bacterial Subdural Empyema in Pediatric Patients After Relaxation of COVID-19 Non-pharmaceutical Interventions (NPIs)

INTRODUCTION: Non-pharmaceutical interventions (NPIs), in response to the COVID-19 viral pandemic altered viral transmission. In addition, endemic viral strains (influenza, RSV, etc) also experienced unprecedentedly low infection rates. Endemic viral infections typically followed seasonal outbreak spikes, but these spikes were noticeably absent in the COVID-19 control period. After many COVID-19 restrictions were ceased, there was an unusually high spike in endemic viral infections. Many COVID-19 measures were relaxed in the early/middle part of 2021, and we noted a sharp increase in post-viral, complicated sinusitis/subdural empyema cases. METHODS: Data collection was via retrospective chart review of subdural empyema cases at our institution. “Post-viral” was defined as positive viral test or VURI symptoms within 30 days. RESULTS: Our group previously published our case series on the management of subdural empyema. That served as an historical cohort of 16 patients and 23 procedures over an 8 year period (July 2013-June 2021). During the previous academic year, July 2021 to June 2022, there were a total of 14 patients and 19 surgeries, which nearly doubles the previous 8 years combined. The current academic year (to date) has had 9 empyema patients and 12 surgical cases. 100% of patients in the previous 2 years has had historical symptoms of viral URI symptoms or positive viral URI testing within 30 days. None were documented positive for COVID-19. In less than 2 years since many NPIs were lifted, post-viral, bacterial empyema cases have increased dramatically by a fold of 2.56. CONCLUSIONS: NPIs may have created an endemic viral “immunity gap” and an immunologically susceptible population, and thereby could have contributed to a sharp increase in bacterial subdural empyema.

Immunogenicity of Enhanced Influenza Vaccines Against Mismatched Influenza Strains in Older Adults: A Review of Randomized Controlled Trials.

Antigenic drift is a major driver of viral evolution and a primary reason why influenza vaccines must be reformulated annually. Mismatch between vaccine and circulating viral strains negatively affects vaccine effectiveness and often contributes to higher rates of influenza-related hospitalizations and deaths, particularly in years dominated by A(H3N2). Several countries recommend enhanced influenza vaccines for older adults, who are at the highest risk of severe influenza complications and mortality. The immunogenicity of enhanced vaccines against heterologous A(H3N2) strains has been examined in nine studies to date. In six studies, an enhanced, licensed MF59-adjuvanted trivalent inactivated influenza vaccine (aIIV3) consistently increased heterologous antibody titers relative to standard influenza vaccine, with evidence of a broad heterologous immune response across multiple genetic clades. In one study, licensed high-dose trivalent inactivated influenza vaccine (HD-IIV3) also induced higher heterologous antibody titers than standard influenza vaccine. In a study comparing a higher dose licensed quadrivalent recombinant influenza vaccine (RIV4) with HD-IIV3 and aIIV3, no significant differences in antibody titers against a heterologous strain were observed, although seroconversion rates were higher with RIV4 versus comparators. With the unmet medical need for improved influenza vaccines, the paucity of studies especially with enhanced vaccines covering mismatched strains highlights a need for further investigation of cross-protection in older adults.

Efficacy and immunogenicity following dengue virus-1 human challenge after a tetravalent prime-boost dengue vaccine regimen: an open-label, phase 1 trial

Dengue human infection models (DHIMs) are important tools to down-select dengue vaccine candidates and establish tetravalent efficacy before advanced clinical field trials. We aimed to provide data for the safety and immunogenicity of DHIM and evaluate dengue vaccine efficacy. We performed an open-label, phase 1 trial at the University of Maryland (Baltimore, MD, USA). Eligible participants were healthy individuals aged 18-50 years who either previously received a tetravalent dengue purified inactivated vaccine prime followed by a live-attenuated vaccine boost (ie, the vaccinee group), or were unvaccinated flavivirus-naive participants (ie, the control group). Participants in the vaccinee group with detectable pre-challenge dengue virus-1 neutralising antibody titres and flavivirus-naive participants in the control group were inoculated with dengue virus-1 strain 45AZ5 in the deltoid region, 27-65 months following booster dosing. These participants were followed-up from days 4-16 following dengue virus-1 live virus human challenge, with daily real-time quantitative PCR specific to dengue virus-1 RNA detection, and dengue virus-1 solicited local and systemic adverse events were recorded. The primary outcomes were safety (ie, solicited local and systemic adverse events) and vaccine efficacy (ie, dengue virus-1 RNAaemia) following dengue challenge. This study is registered with ClinicalTrials.gov, number NCT04786457. In January 2021, ten eligible participants were enrolled; of whom, six (60%) were in the vaccinee group and four (40%) were in the control group. Daily quantitative PCR detected dengue virus-1 RNA in nine (90%) of ten participants (five [83%] of six in the vaccinee group and all four [100%] in the control group). The mean onset of RNAaemia occurred on day 5 (SD 1·0) in the vaccinee group versus day 8 (1·5) in the control group (95% CI 1·1-4·9; p=0·007), with a trend towards reduced RNAaemia duration in the vaccinee group compared with the control group (8·2 days vs 10·5 days; 95% CI -0·08 to 4·68; p=0·056). Mild-to-moderate symptoms (nine [90%] of ten), leukopenia (eight [89%] of nine), and elevated aminotransferases (seven [78%] of nine) were commonly observed. Severe adverse events were detected only in the vaccinee group (fever ≥38·9°C in three [50%] of six, headache in one [17%], and transient grade 4 aspartate aminotransferase elevation in one [17%]). No deaths were reported. Participants who had tetravalent dengue purified inactivated vaccine prime and live-attenuated vaccine boost were unprotected against dengue virus-1 infection and further showed increased clinical, immunological, and transcriptomic evidence for inflammation potentially mediated by pre-existing infection-enhancing antibodies. This study highlights the impact of small cohort, human challenge models studying dengue pathogenesis and downstream vaccine development. Military Infectious Disease Research Program and Medical Technology Enterprise Consortium and Advanced Technology International.

Factors Associated with Influenza-like Illness among Inmates in an All-male Prison, Songkhla Province, Thailand, 2023

On 9 Feb 2023, the Office of Disease Prevention and Control Region 12Songkhlawas informed of an influenza-like illness (ILI) cluster in an all-male prison in Songkhla Province. We investigated to identify the causative agent, possible sources and risk factors, and provide control measures. We conducted an active case finding by interviewing inmates and officers. Prison facilities and hygiene behaviors of inmates and officers were inspected. A retrospective cohort study was performed. Basic and effective reproductive numbers were estimated. The overall attack rate was 12.6% (474/3,648). Most cases were inmates from Wing C (80.4%). There were no severe cases or deaths. Of ten specimens tested, all were positive for influenza B/Victoria lineage, V1a.3a.2. Fifty-four percent of inmates had received influenza vaccine within the last 12 months. A mismatch between the viral strain in the vaccine and the one causing this outbreak likely contributed to the outbreak as the vaccine provided to the inmates was manufactured during the previous year's influenza season. Vaccine effectiveness was 36.2% against ILI. Having high-risk conditions (adjusted odds ratios (AOR) 2.83, 95% confidence interval (CI) 1.27–6.32) and sharing drinking glasses (AOR 2.02, 95% CI 1.21–3.36) were significant risk factors. The basic reproductive number for ILI in this outbreak was 1.36. The effective reproductive number ranged from 0.18–3.69. For effective management of ILI outbreaks in prisons, a continuous program of influenza vaccination following updated World Health Organization recommendations and a comprehensive surveillance system with rigorous respiratory illness management practices are suggested.

SARS-CoV-2 and Angiotensin-Converting Enzyme-2 Receptor Interaction Blocker– an In-Silico Approach

The global COVID-19 pandemic, instigated by the Severe Acute Respiratory Syndrome Coronavirus 2 (SARS-CoV-2), has led to substantial morbidity and mortality on a worldwide scale. While COVID-19 vaccines offer hope, the emergence of mutated viral strains necessitates the development of FDA-approved drugs to address future outbreaks. Objective: To examine prospective antiviral medications through an analysis of the interaction between the spike protein of SARS-CoV-2 and Angiotensin-converting enzyme-2 (ACE-2) receptors, which play a pivotal role in facilitating viral entry into host cells. Methods: Molecular docking was employed to assess the binding affinities of various protease inhibitors with ACE-2 receptors. Natural proteases, including Furin and Transmembrane serine protease 2 (TMPRSS2), cleave viral spike proteins into S1 and S2 subunits, facilitating fusion with ACE-2 receptors. We assessed the binding energies of Indinavir, Nafamostat, Fosamprenavir, Lopinavir, and Boceprevir to inhibit this interaction with a sense of optimism for their potential therapeutic applications. Results: Our findings suggest potential treatments for COVID-19, with Indinavir, Nafamostat, Fosamprenavir, Lopinavir, and Boceprevir displaying promising binding energies of -9.6 kcal/mol, -8.4 kcal/mol, -7.7 kcal/mol, and -7.5 kcal/mol, respectively. Conclusions: While promising, further clinical trials are important to potentially evaluate the efficacy and safety of these proposed drugs in combating COVID-19 and its variants.

Assessing immune evasion potential and vaccine suitability of a feline panleukopenia virus strain

Since the introduction of the feline panleukopenia virus (FPV) vaccine in China in 2011, it has played a crucial role in safeguarding the health of numerous pet cats by preventing FPV infections. However, an observed rise in FPV infections among cats previously vaccinated has prompted our investigation. Our laboratory has identified a specific FPV isolate, FPV-251, which raises concerns about its potential to evade the immune response. To validate this hypothesis, we conducted a correlational study on FPV-251. Ten sera samples were collected from ten cats two months after receiving the vaccine three times. These samples were prepared in the laboratory to assess their ability to neutralize FPV-251. Results indicated that the neutralization titers of the 10 sera ranged from 1:313.7 to 1:1051.0, with an average titer of 1:627.4. Considering the diversity and complexity of clinical practice, we expanded our study to include 86 sera samples collected from cats at the clinic after three-time immunizations. Among these, 8 out of 43 sera collected after one year post three-time immunizations and 5 out of 43 sera collected within one year post three-time immunizations exhibited a neutralization index (NI) of less than 50 against FPV-251. Despite its potential immune evasion capabilities, immunization with inactivated FPV-251 demonstrated effectiveness in providing substantial protection for cats. This was evident from the high levels of sera antibodies against FPV-251 in cats with FPV-251 immunization, as well as their ability to survive and maintain good health after being challenged with FPV-251. Furthermore, sera antibodies from immunized cats displayed the ability to neutralize the other five FPV isolates, indicating a robust cross-protection capacity of the FPV-251 vaccine. Our research findings suggest that although FPV-251 may exhibit certain immune evasion capabilities, it holds significant potential for development into a vaccine to protect pet cats from FPV infection.

Molecularly generated rat hepatitis E virus strains from human and rat show efficient replication in a human hepatoma cell line

The hepatitis E virus (HEV) can cause acute and chronic hepatitis in humans. Whereas HEV genotypes 1–4 of species Paslahepevirus balayani are commonly found in humans, infections with ratHEV (species Rocahepevirus ratti) were previously considered to be restricted to rats. However, several cases of human ratHEV infections have been described recently. To investigate the zoonotic potential of this virus, a genomic clone was constructed here based on sequence data of ratHEV strain pt2, originally identified in a human patient with acute hepatitis from Hongkong. For comparison, genomic clones of ratHEV strain R63 from a rat and of HEV genotype 3 strain 47832mc from a human patient were used. After transfection of in vitro-transcribed RNA from the genomic clones into the human hepatoma cell line HuH-7-Lunet BLR, virus replication was shown for all strains by increasing genome copy numbers in cell culture supernatants. These cells developed persistent virus infections, and virus particles in the culture supernatant as well as viral antigen within the cells were demonstrated. All three generated virus strains successfully infected fresh HuH-7-Lunet BLR cells. In contrast, the human hepatoma cell lines HuH-7 and PLC/PRF/5 could only be infected with the genotype 3 strain and to a lesser extent with ratHEV strain R63. Infection of the rat-derived hepatoma cell lines clone 9, MH1C1 and H-4-II-E did not result in efficient virus replication for either strain. The results indicate that ratHEV strains from rats and humans can infect human hepatoma cells. The replication efficiency is strongly dependent on the cell line and virus strain. The investigated rat hepatoma cell lines could not be infected and other rat-derived cells should be tested in future to identify permissive cell lines from rats. The developed genomic clone can represent a useful tool for future research investigating pathogenicity and zoonotic potential of ratHEV.

Effects of Strain Differences, Humidity Changes, and Saliva Contamination on the Inactivation of SARS-CoV-2 by Ion Irradiation.

One of the methods to inactivate viruses is to denature viral proteins using released ions. However, there have been no reports detailing the effects of changes in humidity or contamination with body fluids on the inactivation of viruses. This study investigated the effects of humidity changes and saliva contamination on the efficacy of SARS-CoV-2 inactivation with ions using multiple viral strains. Virus solutions with different infectious titers were dropped onto a circular nitrocellulose membrane and irradiated with ions from 10 cm above the membrane. After the irradiation of ions for 60, 90, and 120 min, changes in viral infectious titers were measured. The effect of ions on virus inactivation under different humidity conditions was also examined using virus solutions containing 90% mixtures of saliva collected from 10 people. A decrease in viral infectivity was observed over time for all strains, but ion irradiation further accelerated the decrease in viral infectivity. Ion irradiation can inactivate all viral strains, but at 80% humidity, the effect did not appear until 90 min after irradiation. The presence of saliva protected the virus from drying and maintained infectiousness for a longer period compared with no saliva. In particular, the Omicron strain retained its infectivity titer longer than the other strains. Ion irradiation demonstrated a consistent reduction in the number of infectious viruses when compared to the control across varying levels of humidity and irradiation periods. This underscores the notable effectiveness of irradiation, even when the reduction effect is as modest as 50%, thereby emphasizing its crucial role in mitigating the rapid dissemination of SARS-CoV-2.

Some biological properties of сhloriridovirus from Culiseta mosquitoes (Diptera: Culicidae)

Two strains of mosquito iridescent viruses (Chloriridovirus) were isolated in Ukraine from seek larvae of bloodsucking mosquitoes Culiseta annulata (Schrank, 1776) and Culiseta morsitans (Theobald, 1901). Electron microscopic study of tissues from these larvae revealed icosahedral virus particles ranging from 180 nm to 5 nm in diameter, containing dense, pleomorphic nucleotides. Viruses were assembled in the cytoplasm within spherical virosomes. Both viruses contained DNA and 11 polypeptides with molecular weights varying from 16 kD to 98 kD. A DNA restriction analysis of both strains of mosquito chloriridovirus of the genus Culiseta and cloning of fragments of their genomes by genetic engineering methods was performed. Isolated strains were sensitive to ultraviolet insolation and heating and were stable to organic solvents such as ether and chloroform. Both isolated strains grew well in mosquito (Aedes aegypti, Aedes pseudoscutellaris, Aedes albopictus) and in Lepidoptera (Euxoa scandens, Antheraea pernyi) cell lines. A close antigenic relationship has been found between isolated strains and Chloriridovirus from Aedes cantans. Some antigenic relationship was also demonstrated between isolated strains and still unclassified iridovirus from carp (Cyprinus carpio). These findings imply that both strains share some similarity in structural and biochemical characteristics and belong to the Chloriridovirus genus of the Iridoviridae family