Genetic detection and analysis of porcine norovirus in pigs farmed in north Vietnam.

Norovirus (NoV) causing gastroenteritis symptoms, which has been reported in several hosts, including humans, pigs, and rats. This study was conducted to identify porcine viral infection and to characterize NoV strains from pigs in some provinces in north Vietnam. Totally, 102 fecal samples from diarrheal pigs on farms in six cities and provinces in northern Vietnam during July 2022 to March 2023 were collected. Polymerase chain reaction was used to identify the viral genome. Positive samples were used for nucleotide sequencing of the partial RNA-dependent RNA polymerase gene sequence. Five (4.9 %) positive stool samples were detected from animals farmed in five different farms, with one positive animal identified in each farm. Genetic analysis indicated that nucleotide identity was in the range 97.77-99.62 % among the 5 NoVs in this study. Phylogenetic analysis pointed out that the five NoVs were Genotype II.19 viruses. Genetically, these strains were closely related to porcine NoV strains that were reported in China in 2009.

Detection of feline immunodeficiency virus by neutral red-based loop-mediated isothermal amplification assay.

Background and Aim: Feline immunodeficiency virus (FIV) is a retroviral pathogen globally responsible for immunodeficiency disease in cats. However, the current diagnosis based on antibody detection has limitations and can also produce false-positive results. This study aimed to develop a one-pot loop-mediated isothermal amplification (LAMP) process integrated with neutral red (NR-LAMP) assay for detection of FIV proviral DNA. Materials and Methods: We developed a one-pot, gag gene-based NR-LAMP for convenient, rapid, specific, and sensitive colorimetric inspection of FIV proviral DNA. Results: The developed NR-LAMP was capable of amplifying at an optimum temperature of 65°C for 40 min. No cross-amplification was detected between FIV and other feline viruses tested, indicating the high specificity (98.44%) of the novel FIV-LAMP primer. Our NR-LAMP assay has a detection limit of 4.2 × 101 copies/µL. A total of 80 clinical samples with a background of FIV infection were collected and tested using the proposed method. The NR-LAMP assay showed a high sensitivity of 100% compared to conventional polymerase chain reaction assay. Conclusion: These results support the suitability of NR-LAMP as a potential future alternative clinical molecular approach for further use in the diagnosis of FIV-infected cats.

The first study on clinicopathological changes in cats with feline infectious peritonitis with and without retrovirus coinfection.

Background and Aim: Feline infectious peritonitis (FIP) is an infectious, immune-mediated, and fatal disease in cats caused by a mutant feline coronavirus (FCoV) infection. Feline immunodeficiency virus (FIV) and feline leukemia virus (FeLV) are two common retroviruses that play a role in reducing feline immune function with opportunistic retrovirus infection being a predisposing factor for the development of FIP. This study aimed to evaluate the clinicopathological parameters of FIP in cats with and without retrovirus coinfection. Materials and Methods: In total, 62 cats presenting with pleural and/or peritoneal effusion at the Kasetsart University Veterinary Teaching Hospital, Bangkok, Thailand, were selected for the study. Effusion samples were collected and a reverse transcriptase-polymerase chain reaction (RT-PCR) assay was performed on all samples using the 3' untranslated region primer. All FCoV-positive cats were tested for retrovirus infection using a commercial kit (Witness FeLV-FIV [Zoetis]; United States). Clinical signs, hematological, and biochemical parameters of these cats were investigated and grouped. Results: Of the 62 cats with pleural and/or peritoneal effusion, FCoV was detected in 32, of which 21 were highly suspicious for FIP. The cats suspected of FIP were divided into three subgroups following viral detection. A total of 14 had only FCoV infection (Group A), four had FCoV and FeLV infection (Group B), and three had FCoV, FeLV, and FIV infection (Group C). Of the rest, 11 had definitive diagnoses, which included three being FCoV and FeLV-positive (Group D), and eight were retrovirus-negative (Group E). Mild anemia and lymphopenia were found in cats infected with these three viruses. An albumin-to-globulin ratio lower than 0.5 was found in FIP cats with only FCoV infection. Conclusion: Typically, cats with clinical effusion and FIP, with and without retrovirus coinfection, had similar hematological findings. Clinical signs, blood parameters, fluid analysis with cytological assessment, and RT-PCR assays could identify better criteria to diagnose FIP with and without retrovirus coinfection.

Risk factors and clinical and laboratory findings associated with feline immunodeficiency virus and feline leukemia virus infections in Bangkok, Thailand.

Background and Aim: Feline leukemia virus (FeLV) and feline immunodeficiency virus (FIV) are retroviruses associated with chronic and neoplastic diseases in domestic and non-domestic cats. There has been increasing interest in the clinical importance of feline retroviruses in Thailand and the identification of associated risk factors in domestic cats. To prevent the spread of retroviral diseases and improve the management of retrovirus-infected cats, risk factors and associated clinical laboratory data must be clearly understood. This study aimed to identify the influence of household, lifestyle, health status, sterilization, clinical presentations, and laboratory findings on FIV- and FeLV-infected cats in Bangkok, Thailand. Materials and Methods: A total of 480 cats were evaluated for FeLV p27 antigen and FIV antibodies using Witness FeLV-FIV Rapid Test and SNAP FIV/FeLV Combo Test at a veterinary hospital service. Results: Of the 480 cats tested, 113 were positive for virus infection, including 60 for FeLV (12.5%), 40 for FIV (8.3%), and 13 for both FeLV and FIV (2.7%). The findings revealed that the risk factors for cats infected with FeLV, FIV, or both FeLV and FIV were significantly different compared with those for non-infected cats (p < 0.05). Multivariate analysis showed that multi-cat ownership is a risk factor for the high prevalence of feline retrovirus infection, as multi-cat households exhibited a higher prevalence of infection than single-cat households. Anemic and sick cats were also at a greater risk of testing positive for specific retrovirus infections. FeLV-infected cats had a higher risk of anemia and low erythrocyte and thrombocyte counts (p ≤ 0.0001), whereas FIV-infected cats were more likely to have anemia and leukocytopenia than controls. Conclusion: Knowledge of the risk factors for retroviral diseases and associated clinical and laboratory findings can be used to develop strategies to reduce FIV and FeLV infections in cats.

Tumor suppressor REIC/DKK-3 and co-chaperone SGTA: Their interaction and roles in the androgen sensitivity.

REIC/DKK-3 is a tumor suppressor, however, its intracellular physiological functions and interacting molecules have not been fully clarified. Using yeast two-hybrid screening, we found that small glutamine-rich tetratricopeptide repeat-containing protein α (SGTA), known as a negative modulator of cytoplasmic androgen receptor (AR) signaling, is a novel interacting partner of REIC/DKK-3. Mammalian two-hybrid and pull-down assay results indicated that the SGTA-REIC/DKK-3 interaction involved the N-terminal regions of both REIC/DKK-3 and SGTA and that REIC/DKK-3 interfered with the dimerization of SGTA, which is a component of the AR complex and a suppressor of dynein motor-dependent AR transport and signaling. A reporter assay in human prostate cancer cells that displayed suppressed AR signaling by SGTA showed recovery of AR signaling by REIC/DKK-3 expression. Considering these results and our previous data that REIC/DKK-3 interacts with the dynein light chain TCTEX-1, we propose that the REIC/DKK-3 protein interferes with SGTA dimerization, promotes dynein-dependent AR transport and then upregulates AR signaling.