Background Feline panleukopenia virus (FPV) is a widespread and highly infectious pathogen in cats with a high mortality rate. Although Yanji has a developed cat breeding industry, the variation of FPV locally is still unclear. Objectives This study aimed to isolate and investigate the epidemiology of FPV in Yanji between 2021 and 2022. Methods A strain of FPV was isolated from F81 cells. Cats suspected of FPV infection (n = 80) between 2021 and 2022 from Yanji were enrolled in this study. The capsid protein 2 (VP2) of FPV was amplified. It was cloned into the pMD-19T vector and transformed into a competent Escherichia coli strain. The positive colonies were analyzed via VP2 Sanger sequencing. A phylogenetic analysis based on a VP2 coding sequence was performed to identify the genetic relationships between the strains. Results An FPV strain named YBYJ-1 was successfully isolated. The virus diameter was approximately 20–24 nm, 50% tissue culture infectious dose = 1 × 10 −4.94 /mL, which caused cytopathic effect in F81 cells. The epidemiological survey from 2021 to 2022 showed that 27 of the 80 samples were FPV-positive. Additionally, three strains positive for CPV-2c were unexpectedly found. Phylogenetic analysis showed that most of the 27 FPV strains belonged to the same group, and no mutations were found in the critical amino acids. Conclusions A local FPV strain named YBYJ-1 was successfully isolated. There was no critical mutation in FPV in Yanji, but some cases with CPV-2c infected cats were identified.

Gosling plague (GP) is an acute and hemorrhagic infectious disease caused by goose parvovirus (GPV). The goose industry suffers significant economic losses as a result of GP, which is found to be widespread worldwide, with high rates of morbidity and mortality. Our group developed a novel technique for detecting GPV nanoparticle-assisted polymerase chain reaction (nanoPCR) and the characterization of its specificity and sensitivity. It was developed by using the traditional polymerase chain reaction (PCR) and nanoparticles. The findings of this study revealed that GPV nanoPCR products were 389 bp in length, and the lower limit of the nanoPCR assay was 4.68 × 102 copies/μL, whereas that of the conventional PCR assay was 4.68 × 104 copies/μL. A total of 230 geese suspected of GPV were detected using nanoPCR, with a positive rate of 83.0% and a specificity of 73%, respectively. Overall, we present a hitherto undocumented method for identifying GPV by using nanoPCR to aid in the evaluation of subclinical illness.

Canine parvovirus 2 (CPV2) causes one of the most serious canine viral infections, with high mortality in young dogs. In 2014, 2019, and 2021, we determined genetic sequences of CPV2 strains obtained from 39 fecal samples collected from the Yanbian Korean Autonomous Prefecture in the Jilin Province of China. Sequence alignments were performed using the major capsid protein ( VP2) gene; protein sequences of these samples had high nucleotide (>97.4%) and amino acid (>95.6%) identity. All of the amino acid sequences contained Ser297Ala and Tyr324Ile mutations. Our survey indicated a high prevalence of CPV2 variants in Yanbian Prefecture, with the new CPV2a variant (26 of 39; 67%) being the most frequent. CPV2c, identified in 9 of 39 (23%) samples, had not been detected in this region previously, indicating the potential risk of CPV2 mutation. The sequences of our 39 CPV2 samples were more highly homologous to the published Chinese strains than to the CPV2 variant strains found in other countries.

Gosling plague (GP) is caused by goose parvovirus (GPV) gosling acute, subacute, and septic infectious diseases, commonly known as gosling plague. At present, the prevention and control of GP at home and abroad mainly adopts the method of immunizing female geese with attenuated vaccine. Goslings can be immunized, but there are still the phenomenon of dispersive virus and virulence reverse. It, therefore, is urgent to develop a new safe and effective vaccine. The recombinant avian pox virus vaccines rFPV-GoIFNγ, rFPV-GPV-VP3 and rFPV-GoIFNγ-VP3 were used to monitor their antibody levels and evaluate the protective mechanism of the vaccine in this study. This study lays a foundation for further in vivo testing of recombinant avian pox virus vaccine for goose parvovirus and provides a reference for the development of recombinant avian pox virus vaccine for other avian infectious diseases.