Novel mutation N588 residue in the NS1 protein of feline parvovirus greatly augments viral replication.

Feline parvovirus (FPV) infection is highly fatal in felines. NS1, which is a key nonstructural protein of FPV, can inhibit host innate immunity and promote viral replication, which is the main reason for the severe pathogenicity of FPV. However, the mechanism by which the NS1 protein disrupts host immunity and regulates viral replication is still unclear. Here, we identified an FPV M1 strain that is regulated by the NS1 protein and has more pronounced suppression of innate immunity, resulting in robust replication. We found that the neutralization titer of the FPV M1 strain was significantly lower than that of the other strains. Moreover, FPV M1 had powerful replication ability, and the FPV M1-NS1 protein had heightened efficacy in repressing interferon-stimulated genes (ISGs) expression. Subsequently, we constructed an FPV reverse genetic system, which confirmed that the N588 residue of FPV M1-NS1 protein is a key amino acid that bolsters viral proliferation. Recombinant virus containing N588 also had stronger ability to inhibit ISGs, and lower ISGs levels promoted viral replication and reduced the neutralization titer of the positive control serum. Finally, we confirmed that the difference in viral replication was abolished in type I IFN receptor knockout cell lines. In conclusion, our results demonstrate that the N588 residue of the NS1 protein is a critical amino acid that promotes viral proliferation by increasing the inhibition of ISGs expression. These insights provide a reference for studying the relationship between parvovirus-mediated inhibition of host innate immunity and viral replication while facilitating improved FPV vaccine production.IMPORTANCEFPV infection is a viral infectious disease with the highest mortality rate in felines. A universal feature of parvovirus is its ability to inhibit host innate immunity, and its ability to suppress innate immunity is mainly accomplished by the NS1 protein. In the present study, FPV was used as a viral model to explore the mechanism by which the NS1 protein inhibits innate immunity and regulates viral replication. Studies have shown that the FPV-NS1 protein containing the N588 residue strongly inhibits the expression of host ISGs, thereby increasing the viral proliferation titer. In addition, the presence of the N588 residue can increase the proliferation titer of the strain 5- to 10-fold without affecting its virulence and immunogenicity. In conclusion, our findings provide new insights and guidance for studying the mechanisms by which parvoviruses suppress innate immunity and for developing high-yielding FPV vaccines.

Complete genome sequence analysis of Reticuloendotheliosis virus integrated in nonhomologous Avipoxvirus.

Integration of nucleic acid sequences of Reticuloendotheliosis virus (REV) in Avipoxvirus（APV） has become commonplace. In this study, 4 strains of suspected Fowlpox virus (FPV) and 1 strain of suspected Pigeonpox virus (PPV) collected in Taiyuan, Shanxi Province were cultured in chicken embryos, and the 4b core protein gene was amplified by PCR, and the identity and genome similarity were determined by sequence analysis. The sequences between the end of ORF201 and the beginning of ORF203 of FPV and PPV were then amplified, sequenced, and subjected to sequence comparison to determine genome similarity. The results showed that the isolates were 4 strains of FPV and 1 strain of PPV. The 4 isolated strains of FPV belong to type A1 virus, with 100 % identity to each other and to the FWPV-09-Jilin strain isolated in Jilin, China, and the lowest identity to the type B2 virus TNPV5/NZL/2009, which is only 74 %. PPV belongs to type A2 virus, and its identity with local strain of fowlpox virus was 90.1 %, with the highest identity of 100 % with PPLH and ROPI/W370/ON/2012 and ow_2017_3 strains, which also belong to type A2 pigeonpox virus, and the lowest identity of 73.7 % with TNPV5/NZL/2009, a type B2 virus. The complete genome of REV sequences integrated into FPV and PPV were amplified, and 5 REV nucleic acid sequences were obtained after sequencing and concatenation, with lengths ranging from 7942 to 8005 bp. The identity analysis results indicate that it has high identity with isolates from Northeast China, Guangdong, and Guangxi regions in China. Based on its gp90 protein gene, the REV integrated into the poxvirus belong to type III, with the highest identity of 99.9% with strains such as APC-566 and CY1111, and the lowest identity with REV-Anhui1, at 95.4 %. The length of the pol gene varies among different strains of REV, and its encoded amino acid changes significantly after position 675, with deletions and alterations. This study indicates that all fowlpox viruses isolated in Taiyuan, Shanxi Province have integrated the entire REV gene sequence, with high identity between them. At the same time, it indicates that the pigeonpox virus isolate has also integrated the entire REV gene sequence, and has the highest identity with the integrated REV gene sequence in fowlpox virus.

Identification and Genome Characterization of Novel Feline Parvovirus Strains Isolated in Shanghai, China.

Feline panleukopenia virus (FPV) is the causative agent of hemorrhagic gastroenteritis in feline animals. FPV has been evolving over time, and there have been several different strains of the virus identified. Some of these strains may be more virulent or more resistant to current vaccines than others, which highlights the importance of ongoing research and monitoring of FPV evolution. For FPV genetic evolution analysis, many studies focus on the main capsid protein (VP2), but limited information is available on the nonstructural gene NS1 and structural gene VP1. In the present study, we firstly isolated two novel FPV strains circulating in Shanghai, China, and performed full-length genome sequencing for the desired strains. Subsequently, we focused on analyzing the NS1, VP1 gene, and the encoding protein, and conducted a comparative analysis among the worldwide circulating FPV and Canine parvovirus Type 2 (CPV-2) strains, which included the strains isolated in this study. We found that the 2 structural viral proteins, VP1 and VP2, are splice variants, and VP1 has a 143 amino-acid-long N-terminal compared to VP2. Furthermore, phylogenetic analysis showed that divergent evolution between FPV and CPV-2 virus strains were clustered mostly by country and year of detection. In addition, much more continuous antigenic type changes happened in the process of CPV-2 circulating and evolution compared to FPV. These results stress the importance of the continuous study of viral evolution and provide a comprehensive perspective of the association between viral epidemiology and genetic evolution.

Development of a triple NanoPCR method for feline calicivirus, feline panleukopenia syndrome virus, and feline herpesvirus type I virus.

BACKGROUND: Feline calicivirus (FCV), Feline panleukopenia virus (FPV), and Feline herpesvirus type I (FHV-1) are the three most common pathogens in cats, and also are the main pathogens leading to the death of kittens. Here, by a combination of gold nanoparticles and conventional PCR, we established a novel triple NanoPCR molecular detection method for clinical detection. RESULTS: The triple NanoPCR molecular detection is able to detect 2.97 × 101copies/µL FCV recombinant copies plasmid per reaction, 2.64 × 104copies/µL FPV recombinant copies plasmid per reaction, and 2.85copies/µL FHV-1 recombinant copies plasmid per reaction at the same time. The sensitivity of each plasmid is 100 times, 10 times, and 100 times higher than conventional PCR, respectively. The clinical results showed that among the 38 samples, the positive rates of FCV, FPV, and FHV-1 in a NanoPCR test were 63.16, 31.58, and 60.53%, while in a conventional PCR were 39.47, 18.42, and 34.21%. CONCLUSIONS: In this report, it is the first time that NanoPCR assays are applied in the detection of FCV, FPV, and FHV-1 as well. This sensitive and specific NanoPCR assay can be widely used in clinical diagnosis and field monitoring of FCV, FPV, and FHV-1 infections.

Molecular characteristics and genetic evolutionary analyses of circulating parvoviruses derived from cats in Beijing.

BACKGROUND: Feline parvovirus (FPV) is a member of the family Parvoviridae, which is a major enteric pathogen of cats worldwide. This study aimed to investigate the prevalence of feline parvovirus in Beijing of China and analyze the genetic features of detected viruses. RESULTS: In this study, a total of 60 (8.5%) parvovirus-positive samples were detected from 702 cat fecal samples using parvovirus-specific PCR. The complete VP2 genes were amplified from all these samples. Among them, 55 (91.7%) sequences were characterized as FPV, and the other five (8.3%) were typed as canine parvovirus type 2 (CPV-2) variants, comprised of four CPV-2c and a new CPV-2b strain. In order to investigate the origin of CPV-2 variants in cats, we amplified full-length VP2 genes from seven fecal samples of dogs infected with CPV-2, which were further classified as CPV-2c. The sequences of new CPV-2b/MT270586 and CPV-2c/MT270587 detected from feline samples shared 100% identity with previous canine isolates KT156833 and MF467242 respectively, suggesting the CPV-2 variants circulating in cats might be derived from dogs. Sequence analysis indicated new mutations, Ala91Ser and Ser192Phe, in the FPV sequences, while obtained CPV-2c carried mutations reported in Asian CPV variants, showing they share a common evolutionary pattern with the Asian 2c strains. Interestingly, the FPV sequence (MT270571), displaying four CPV-specific residues, was found to be a putative recombinant sequence between CPV-2c and FPV. Phylogenetic analysis of the VP2 gene showed that amino acid and nucleotide mutations promoted the evolution of FPV and CPV lineages. CONCLUSIONS: Our findings will be helpful to further understand the circulation and evolution of feline and canine parvovirus in Beijing.

Gastrointestinal ultrasonographic findings in cats with Feline panleukopenia: a case series.

BACKGROUND: Feline panleukopenia virus (FPV) is very resistant and highly contagious and infects domestic cats and other felids. FPV is particularly widespread among sheltered cats, and is associated with high morbidity and mortality, causing severe gastroenteritis characterized by anorexia, lethargy, fever, dehydration, hemorrhagic diarrhea, and vomiting. There is currently no data on the ultrasonographic features of cats affected with FPV. This case series describes abdominal ultrasonographic findings in shelter cats with naturally-occurring FPV, and assesses whether are associated with clinical and laboratory findings. Cats affected by FPV were enrolled in the study if an abdominal ultrasound was performed within 12 hours of diagnosis. Clinical, laboratory and survival data were collected from medical records. Ultrasonographic examinations were reviewed for gastrointestinal abnormalities and their associations with the above data were explored. RESULTS: Twenty-one cats were included. Nine cats (42.9%) died and 12 (57.1%) recovered. Based on ultrasonography, the duodenum and jejunum showed thinning of the mucosal layer in 70.6% and 66.6% of cats, thickening of the muscular layer in 52.9% and 57.1% of cats, and hyperechogenicity of the mucosa in 41.2% and 33.3%. Jejunal hyperechoic mucosal band paralleling the submucosa and irregular luminal surface were both observed in 33.3% of the cats. Survival was positively associated with increased jejunal mucosal echogenicity (P = 0.003) and hyperechoic mucosal band (P = 0.003). Peritoneal free fluid was positively associated with vomiting (P = 0.002). CONCLUSIONS: This study provides ultrasonographic features of naturally-occurring FPV in cats, which, as expected, are compatible with gastroenteropathy. The most frequent findings were diffuse small intestine mucosal layer thinning, muscular layer thickening and mucosal hyperechogenicity, jejunal hyperechoic mucosal band and irregular luminal surface. Ultrasonographic features may be useful to complete the clinical picture and assess the severity of the gastroenteropathy in FPV cats. Prospective studies are needed to confirm ultrasonographic prognostic factors.

Long-term protection against a virulent field isolate of infectious laryngotracheitis virus induced by inactivated, recombinant, and modified live virus vaccines in commercial layers.

Infectious laryngotracheitis (ILT) is an acute respiratory disease of chickens controlled through vaccination with live-modified attenuated vaccines, the chicken embryo origin (CEO) vaccines and the tissue-culture origin (TCO) vaccines. Recently, novel recombinant vaccines have been developed using herpesvirus of turkey (HVT) and fowl pox virus (FPV) as vectors to express ILTV immunogens for protection against ILT. The objective of this study was to assess the protection efficacy against ILT induced by recombinants, live-modified attenuated, and inactivated virus vaccines when administered alone or in combination. Commercial layer pullets were vaccinated with one or more vaccines and challenged at 35 (35 WCH) or 74 weeks of age (74 WCH). Protection was assessed by scoring clinical signs; and by determining the challenge viral load in the trachea at five days post-challenge. The FPV-LT vaccinated birds were not protected when challenged at 35 weeks; the HVT-LT and TCO vaccines in combination provided protection similar to that observed in chickens vaccinated with either HVT-LT or TCO vaccines when challenged at 35 weeks, whereas protection induced by vaccination with HVT-LT followed by TCO was superior in the 74 WCH group compared with the 35 WCH group. Birds given the inactivated ILT vaccine had fewer clinical signs and/or lower viral replication at 74 WCH when combined with TCO or HVT-LT, but not when given alone. Finally, the CEO-vaccinated birds had top protection as indicated by reduction of clinical signs and viral replication when challenged at 35 weeks (74 weeks not done). These results suggest that certain vaccine combinations may be successful to produce long-term protection up to 74 weeks of age against ILT.

Insights into pathological and molecular characterization of avipoxviruses circulating in Egypt.

1. Avipoxvirus (APV) infections are one of many threats inflicting economic losses within the poultry industry, particularly in tropical and subtropical countries. A proper and comprehensive study for APVs is needed to increase the knowledge concerning the diversity and evolution of the virus.2. For this purpose, 136 bird flocks of different species and breeding types were examined for APV infection between October 2016 and November 2017. One hundred and thirty samples had visible pocks on the chorioallantoic membrane (CAM) which were designated as fowl pox-like viruses via amplification of 578 bp from the P4b gene and 1800 bp from the fpv140 locus.4. A comprehensive phylogenetic analysis of fpv167 locus (P4b), fpv140 locus (fpv139 and fpv140) and fpv94 (DNA polymerase) revealed that all the analysed strains belong to fowl pox-like viruses (clade A; subclade A1 and A2). Based on the fpv140 locus full nucleotide sequence, three turkey originated strains were seen to be divergent from chicken originated sequences and branched into novel subclade A1.b.5. Trees comparison, within the term of speculation of virus-host specificity, clearly highlighted a high order specific subgrouping among subclades in the case of the fpv140 locus (including fpv139 and fpv140). Hence, the fowl poxvirus, turkey poxvirus and pigeon poxvirus strains clustered into distinct host-specific subclades A1a, A1.b and A2, respectively, which could not be seen in the FWPV-P4b and DNA polymerase phylogeny.

Two Novel Relative Double-Stranded RNA Mycoviruses Infecting Fusarium poae Strain SX63.

Two novel double-stranded RNA (dsRNA) mycoviruses, termed Fusarium poae dsRNA virus 2 (FpV2) and Fusarium poae dsRNA virus 3 (FpV3), were isolated from the plant pathogenic fungus, Fusarium poae strain SX63, and molecularly characterized. FpV2 and FpV3, with respective genome sequences of 9518 and 9419 base pairs (bps), are both predicted to contain two discontinuous open reading frames (ORFs), ORF1 and ORF2. A hypothetical polypeptide (P1) and a RNA-dependent RNA polymerase (RdRp) are encoded by ORF1 and ORF2, respectively. Phytoreo_S7 domain (pfam07236) homologs were detected downstream of the RdRp domain (RdRp_4; pfam02123) of the ORF2-coded proteins of both FpV2 and FpV3. The same shifty heptamers (GGAAAAC) were both found immediately before the stop codon UAG of ORF1 in FpV2 and FpV3, which could mediate programmed -1 ribosomal frameshifting (-1 PRF). Phylogenetic analysis based on RdRp sequences clearly place FpV2 and FpV3 in a taxonomically unassigned dsRNA mycovirus group. Together, with a comparison of genome organization, a new taxonomic family termed Fusagraviridae is proposed to be created to include FpV2- and FpV3-related dsRNA mycoviruses, within which FpV2 and FpV3 would represent two distinct virus species.

China-origin G1 group isolate FPV072 exhibits higher infectivity and pathogenicity than G2 group isolate FPV027.

Introduction: Feline parvovirus (FPV), a single-stranded DNA virus, is accountable for causing feline panleukopenia, a highly contagious and often lethal disease that primarily affects cats. The epidemiology prevalence and pathogenicity of FPV in certain regions of China, however, remains unclear. The aim of this research was to investigate the epidemiology of FPV in different regions of China in 2021 and compare its infectivity and pathogenicity. Methods: In this research, a total of 36 FPV strains were obtained from diverse regions across China. Phylogenetic analysis was performed based on the VP2 and NS1 sequences, and two representative strains, FPV027 and FPV072, which belonged to different branches, were selected for comparative assessment of infectivity and pathogenicity. Results and discussion: The results revealed that all strains were phylogenetically classified into two groups, G1 and G2, with a higher prevalence of G1 strains in China. Both in vitro and in vivo experiments demonstrated that FPV072 (G1 group) exhibited enhanced infectivity and pathogenicity compared to FPV027 (G2 Group). The structural alignment of the VP2 protein between the two viruses revealed mutations in residues 91, 232, and 300 that may contribute to differences in infectivity and pathogenicity. The findings from these observations will contribute significantly to the overall understanding of the molecular epidemiology of FPV in China and facilitate the development of an effective FPV vaccine.

Complete genome sequence and phylogenetic analysis of feline panleukopenia virus from India.

Parvoviruses are ubiquitous pathogens that cause fatal disease in cats. Feline panleukopenia virus (FPV) is a primitive virus reported first and canine parvovirus (CPV) evolved from FPV and was reported later. Both induce disease in cats and dogs with correlative signs. FPV in domestic cats is genetically diverse and some strains may differ from those used for vaccination. In this study, a virus of FPV strain, ABT/MVC/2022/FPV/001, was identified from a fecal sample of the suspected cat with severe haemorrhagic gastroenteritis. The phylogenetic analysis and complete genome sequence of the strain share 99.75% nucleotide identity with FPV variant MH559110 belonging to Tamil Nadu, India. The results also reveal similarities to strains isolated from Italy, Belgium, and China. The deduced amino acid sequence of isolated strain revealed specific amino acid substitution (Pro5Ala, Phe6Val, His7Gln, Asn9Asp, Lys16Arg, Lys19Arg, Asn52Lys, Gly58Trp, Thr66Ser, Lys67Arg, Leu70His, Asn373Asp and Ala390Thr) which differed from MH559110 and other strains. The complete genomic analysis revealed that the FPV strain circulating in India is evolving rapidly with unique antigenic variations between field FPV, CPV and vaccine strains which may be the major cause for vaccine failure in vaccinated cats. Supplementary Information: The online version contains supplementary material available at 10.1007/s13337-023-00854-7.

Antibody response after feline panleukopenia virus vaccination in kittens with and without intestinal parasites.

OBJECTIVES: Vaccinations should only be given to healthy cats, and deworming before vaccination is generally recommended; however, so far, no study has investigated the influence of intestinal parasitic infection on the immune response in kittens. The aim of this prospective study was to compare the antibody response to feline panleukopenia virus (FPV) vaccination in kittens with and without intestinal parasites. METHODS: Overall, 74 healthy kittens were included. Of these, 17 had intestinal parasites (12/17 Toxocara cati, 6/17 Cystoisospora felis, 1/17 Capillaria species). Both kittens with and without (n = 57) parasites received two primary kitten vaccinations with modified live FPV vaccines in a 4-week interval starting at the age of 8-12 weeks. Anti-FPV antibodies were determined at the beginning of the study (week 0) and at week 8 (4 weeks after the second vaccination) by haemagglutination inhibition. A ⩾four-fold titre increase (week 8 vs week 0) was defined as a response to vaccination. Comparison of the immune response in the kittens with and without intestinal parasites was performed using Pearson's χ2 test. RESULTS: Pre-vaccination antibodies were present in 4/17 (23.5%) kittens with intestinal parasites and in 24/57 (42.1%) without parasites. A ⩾four-fold titre increase was seen in 13/17 (76.5%) kittens with parasites compared with 32/57 (56.1%) kittens without parasites. There was neither a significant difference in pre-vaccination antibodies (P = 0.17), nor in vaccination response (P = 0.13) between kittens with and without parasites. CONCLUSIONS AND RELEVANCE: The results indicate that asymptomatic intestinal infections with endoparasites do not interfere with the immune response to kitten vaccination series. Parasitic infection (at least with T cati, C felis and Capillaria species) is therefore not a reason to postpone important vaccinations.

Techno-enviro-economic analysis of grid-connected solar powered floating PV water pumping system for farmland applications: A numerical design model.

To meet the required load of a farm in the rural area in Mafraq, Jordan, the complete floating photovoltaic (FPV) water pumping sizing, modelling, and optimization of an on-grid PV system with comprehensive capacity, energy output cost, and emission estimations are outlined in this work. The novelty of this study lies in its comprehensive approach that integrates technical, environmental, and economic factors into a unified framework for designing a PV water pumping system, particularly in scenarios where grid supply is feasible or economically viable. A proposal has been made to install PV panels over the water lake to improve the overall system efficiency and to give an aesthetic appearance. The proposed system is composed of a 165 kW PV array and three 55 kW inverters, which cost 54696.92 JD as the initial cost, CO2 emission reduction of more than 5000 tons and produce electricity at 0.028 JD/kWh. The results indicated that the FPV option demonstrates an about 5 % increase in efficiency compared to the other two scenarios. Also, the FPV option has higher costs due to a 25 % increase in system cost but results in lower CO2 emissions compared to the other two options. Top of Form As shown from the results, the two sizing methods for solar water pumping systems, the equations-based method, and the PVsyst simulation tool give the same results. By following this methodology, one can assess the load, size the system, simulate its operation, and analyse the expected performance. Furthermore, the findings of this study could be valuable in designing a grid-connected FPV water pumping system.

Evaluation of the Inactivation Efficacy of Four Disinfectants for Feline Parvovirus Derived from Giant Panda.

Feline panleukopenia (FPL) is a highly contagious acute infectious disease caused by feline parvovirus (FPV). FPV has also been found in giant pandas with clinical signs of vomiting and mild diarrhea, posing a threat to this vulnerable species. Cleaning and disinfection may be one of the most efficacious ways to prevent FPV spread in the habitat of giant pandas. This study evaluated the inactivation effect of peracetic acid (PAA), povidone-iodine (PVP-I), glutaral and deciquam solution (JM) and Virkon S. The tissue culture infective dose (TCID50) assay indicated that the virus may be totally inactivated by JM, PAA and Virkon S. Meanwhile, the hemagglutination (HA) assay showed a high inactivation efficiency of PAA and Virkon S. The analysis of Western blot revealed that PAA, Virkon S and JM can inhibit the structural protein synthesis. Taken together, our findings demonstrated that PAA could rapidly and efficiently inactivate FPV, representing an efficacious disinfectant for FPV control.

Prevalence of Serum Antibody Titers against Core Vaccine Antigens in Italian Cats.

Feline core vaccines strongly recommended for all cats are against Feline panleukopenia virus (FPV), Felid herpesvirus type 1 (FeHV-1), and Feline calicivirus (FCV), but cats can be classified as low- and high-risk based on their lifestyle. The aim of this study was to determine the actual seroprotection against FPV, FeHV-1, and FCV in a large cohort of Italian cats by using the VacciCheck test. A total of 740 cats (567 owned and 173 stray cats; 435 vaccinated and 305 unvaccinated) were analyzed for Protective Antibody Titers (PATs). Differences related to origin, sex, age, breed, FIV/FeLV status, health status, and time elapsed since last vaccination were evaluated. Less than half of the entire cohort (36.4%) had PATs for all three diseases simultaneously, increasing to 48.6% if weak positive values were also considered and 50.3% when considering only the 435 vaccinated cats. Particularly, antibodies were detected against FCV, FPV, and FeHV-1 at protective titers (PATs) in 78.6%, 68.1, and 49.1% of the cats, respectively. In general, owned, neutered, and adult FIV- and/or FeLV-negative cats were the most protected categories, even if not always for the three viruses. Most cats maintained high PATs for 3 years or longer after vaccination against FPV and FCV but not FeHV-1. Long-lasting protective immunity persisted for many years after the last vaccination (more than 18 years in the oldest cats). Nevertheless, since not all cats were protected after so many years and for all pathogens, checking protection via antibody titration could be the best choice to prevent immunity breakdowns. The discussion also focuses on the reliability of antibody titration for the two URTD (upper respiratory tract disease) viruses which, unlike for FPV, is not widely accepted as a valid index of protection.

Circulation of heterogeneous Carnivore protoparvovirus 1 in diarrheal cats and prevalence of an A91S feline panleukopenia virus variant in China.

Cats are susceptible to panleukopenia virus (FPV) and canine parvovirus type 2 (CPV-2) infection. FPV has been recognized as relatively conservative in genetic evolution compared to CPV-2, but information regarding FPV variations in cats is still limited. The aim of this study was to investigate the molecular prevalence of FPV and CPV-2 variants among cats in China. From April 2019 to December 2021, 193 diarrheal faecal samples of cats were collected from Southwest China and 127 (65.80%) samples tested positive to Carnivore protoparvovirus 1. FPV, CPV-2 and some their genomic variants were identified from positive samples, indicating a heterogeneous Carnivore protoparvovirus 1 circulation in the cat population in China. Among FPV strains, an A91S FPV mutant reached the detection rate of 39.37%, which showed that this FPV genomic variant has been prevalent in the tested cats. Moreover, 7 strains of A91S FPV variants were isolated and purified successfully using F81 cells, and the genomes were sequenced. Phylogenetic trees based on the nearly complete genomic sequences, VP2 and NS1 nucleotide sequences showed that the A91S FPV variants were located in the FPV clade, but all clustered into a separate branch. Structural prediction showed that A91S mutation in VP2 protein extended the random coil of aa residues from 92-95 to 91-95. Moreover, the analysis of all complete VP2 sequences of FPV and CPV-2 available in the GenBank database revealed that the A91S FPV variant has been prevalent in China since 2017 and has reported in four other countries in cats. Thus, our study revealed that heterogeneous Carnivore protoparvovirus 1 are circulating in the cat population in China, and first reported the prevalence and genomic characteristics of the A91S FPV variant, which contributed to a better understanding of the molecular prevalence and genetic evolution of FPV in cats.

Floating photovoltaics performance simulation approach.

Floating photovoltaics (FPVs) provide various benefits especially where land is scarce (e.g., reducing land occupancy, water evaporation and environment control…), or when they are combined with hydropower plants (enhanced capacity factor and green energy generation). Software such as PV∗SOL, SAM and PVSyst® are commonly used for the design and simulation of land-based photovoltaic (PV) systems. However, when it comes to the simulation of photovoltaics installed on water surface, such software does not offer the option to directly simulate FPV systems. In this work, a new approach combining MATLAB and Rhino/Grasshopper environments is proposed for the assessment of FPV systems performance. The approach is divided into various steps considering major influencing parameters such as temperature, irradiance, albedo, PV modelling, panel rows spacing, tilt angle, as well as the benefits of including a tracking mechanism. The proposed approach was validated against PV∗SOL simulations for land-based PV systems with a small deviation of less than 2.4%. FPVs simulations considering climatic conditions of Stechovice, Czechia, showed an increase of the performance in the range of 3% compared to terrestrial PVs. This result is in accordance with some published studies based on real FPVs installations. Finally, the developed approach was applied in the simulations of two large-scale FPV systems with different designs (fixed and with a tracking mechanism) including economical aspects.

Carnivore protoparvovirus 1 (CPV-2 and FPV) Circulating in Wild Carnivores and in Puppies Illegally Imported into North-Eastern Italy.

The illegal trade of animals poses several health issues to the global community, among which are the underestimated risk for spillover infection and the potential for an epizootic in both wildlife and domestic naïve populations. We herein describe the genetic and antigenic characterization of viruses of the specie Carnivore protoparvovirus 1 detected at high prevalence in puppies illegally introduced in North Eastern Italy and compared them with those circulating in wild carnivores from the same area. We found evidence of a wide diversity of canine parvoviruses (CPV-2) belonging to different antigenic types in illegally imported pups. In wildlife, we found a high circulation of feline parvovirus (FPV) in golden jackals and badgers, whereas CPV-2 was observed in one wolf only. Although supporting a possible spillover event, the low representation of wolf samples in the present study prevented us from inferring the origin, prevalence and viral diversity of the viruses circulating in this species. Therefore, we suggest performing more thorough investigations before excluding endemic CPV-2 circulation in this species.

Prevalence and characteristics of a feline parvovirus-like virus in dogs in China.

In this study, 192 diarrheal fecal samples were collected from 2019 to 2021 for monitoring the molecular prevalence of canine parvovirus 2 (CPV-2) among dogs in Southwest China, and 113 samples were detected as Carnivore protoparvovirus 1-positive. Surprisingly, 28/113 (24.8%) strains were identified as feline parvovirus (FPV)-like viruses based on the key amino acid (aa) residues in VP2. Further, 6 FPV-like strains were successfully isolated and genome sequenced, and phylogenetic trees based on the genome, VP2 and NS1 sequences showed that the 6 FPV-like strains were most genetically related with FPV instead of CPV-2. Interestingly, the VP2 proteins of the FPV-like virus contained all key aa residues typical for FPV and can be 100% identical to that of FPV, but the VP1 intron and NS1 aa sequences exhibited some unique molecular characteristics. The FPV-like isolate could hemagglutinate swine erythrocyte at pH values between 6 and 8, and replicated efficiently in MDCK cell line; moreover, the virus could cause canine systemic infection via oral administration. Further analysis based on VP2 sequences of FPV and CPV-2 in GenBank revealed that the FPV-like virus had already existed among dogs in 4 Asian countries, and have circulated widely in China. This study first confirmed that the FPV-like isolates could efficiently infect dogs, and has been prevalent among dogs in China. Moreover, this study first reported the genome characteristics of the FPV-like virus in dogs, which may represent a novel evolution pattern involving in the cross-species transmission of the virus from cats to dogs.

Development of a TaqMan-based multiplex real-time PCR for simultaneous detection of four feline diarrhea-associated viruses.

Since their recent discovery, the prevalence of novel feline enteric viruses, including feline bocavirus 1 (FBoV-1), feline astrovirus (FeAstV), and feline kobuvirus (FeKoV), has been reported in China. Co-infections of these viruses with feline parvovirus (FPV) are common causes of diarrhea in cats. Viral co-infections are difficult to identify because of their non-specific clinical signs. To detect and identify these viruses, a quick and specific pathogen-testing approach is required. Here, we establish a real-time PCR (qPCR) based on multiple TaqMan probes for the simultaneous detection of FBoV-1, FeAstV, FeKoV, and FPV. Specific primers and TaqMan fluorescent probes were designed to ensure specificity. The results showed that the detection limit of single qPCR was up to 10 copies, and the detection limit of multiplex qPCR was up to 100 copies, with correlation coefficients >0.995 in all cases. Clinical sample detection revealed a 25.19% (34/135) total rate of co-infection among the viruses and a 1.48% (2/135) quadruple infection rate. Thus, this multiplex qPCR approach can serve as a quick, sensitive, and specific diagnostic tool for FBoV-1, FeAstV, FeKoV, and FPV identification, and it may be utilized for routine surveillance of these emerging and reemerging feline enteric viruses.