Darsaniya Punyadarsaniya

Standard serological tests post-vaccination, such as enzyme-linked immunosorbent assay (ELISA), complement fixation, and virus neutralization, are crucial for monitoring African horse sickness (AHS). However, the availability of commercial test kits such as blocking ELISA varies by regions; while they are commonly used in Africa and Europe, their limited availability and high cost in Thailand present significant challenges. Therefore, this study aimed to evaluate an alternative approach using an in-house indirect ELISA based on cell-based monovalent and polyvalent strains of live attenuated AHS virus. This method addresses the cost and accessibility issues faced in Thailand. This study demonstrated promising results: the in-house indirect ELISA showed analytical sensitivity and specificity values of 88.30% and 67.02% for monovalent strains and 87.23% and 84.04% for polyvalent strains, respectively, compared to the blocking ELISA. These findings underscore the efficacy of the in-house ELISA as a viable serodiagnostic tool for AHS. Furthermore, the polyvalent antigen-based in-house indirect ELISA proved to be a reliable alternative for AHS monitoring, particularly in vaccinated horses, offering enhanced specificity. Additionally, this method is simpler, cheaper, faster, and more convenient than blocking ELISA and serum neutralization tests, making it a practical choice for routine AHS surveillance.

Background and Aim: Potassium peroxymonosulfate (PPMS) is a broad-spectrum disinfectant that oxidizes viral protein capsids. The effectiveness of PPMS in killing viruses depends on several factors, including its concentration, contact time, and present of organic materials. This study evaluated the efficacy of PPMS in an aqueous phase. It also applied PPMS to artificially avian influenza virus (AIV)-contaminated carrier surfaces and clothes and compared its effectiveness with that of sodium dichloroisocyanurate (NaDCC) and quaternary ammonium compounds (QAC). Materials and Methods: Four PPMS concentrations (1×, 0.5×, 0.25×, and 0.125×), were evaluated for their virucidal efficacy against Newcastle disease virus (NDV) and AIV in an aqueous phase. The evaluation included testing in the absence and presence of organic materials under different exposure times, such as 5 s, 30 s, 1 min, 3 min, 5 min, 10 min, and 15 min. AIV inactivation was assessed on contaminated carrier surfaces, such as stainless steel, rubber, plastic, and artificially contaminated clothes. Results: In aqueous phase, concentrations of 1×, 0.5×, 0.25×, and 0.125× inactivated NDV in the absence of organic materials within 5 s, 5 s, 5 min, and 15 min at concentrations of 1×, 0.5×, 0.25×, and 0.125×, respectively. In the presence of organic material contamination, NDV could be inactivated within 30 s for 1×, 1 min for 0.5×, and 10 min for 0.25×; however, 0.125× PPMS did not achieve inactivation within 15 min. PPMS concentrations of 1×, 0.5×, 0.25×, and 0.125× inactivated AIV within 5 s, 5 s, 5 s, and 30 s, respectively, in both the absence and presence of organic materials. PPMS at a concentration of 1× could inactivate AIV on all carriers within 30 s. PPMS at 0.5× and 0.25× concentrations could inactivate AIV within 30 s on rubber and plastic; inactivation occurred within 1 min on stainless steel. However, 0.125× PPMS and 1× QAC could not achieve inactivation within 3 min on all carriers. Finally, PPMS concentrations of 1×, 0.5×, 0.25×, and 0.125× inactivated AIV on rayon sheets within 5 s, 30 s, 5 min, and 15 min, respectively. However, the recommended NaDCC concentration achieved inactivation within 10 min, whereas QAC did not achieve inactivation within 15 min. Conclusion: PPMS can inactivate enveloped viruses such as NDV and AIV. Furthermore, PPMS is superior to NaDCC and QAC for inactivating viruses on various carrier surfaces and artificially contaminated clothes. However, the virucidal efficacy of PPMS depends on the optimal concentration, organic material conditions, and exposure/contact timing. Therefore, PPMS is a promising alternative disinfectant crucial for enhancing biosecurity and controlling viruses that contaminate animal farms, slaughterhouses, and hospitals. Keywords: avian influenza virus, disinfectant, Newcastle disease virus, potassium peroxymonosulfate, virucidal.

The study evaluated potassium peroxymonosulfate (PPMS) efficacy against rifampicin-resistant Salmonella Infantis (rif-SI), Escherichia coli (E. coli), Salmonella Infantis (SI), Newcastle disease virus (NDV) and avian influenza virus (AIV). The assessment encompassed varied concentrations, organic material conditions, and exposure durations to comprehensively evaluate PPMS efficacy. Moreover, PPMS’s efficacy was tested on diverse carrier surfaces and clothing to evaluate its bactericidal and virucidal potential. At the recommended concentrations (1X), PPMS effectively inactivated all pathogens within 5 sec, except for NDV, which required 30 sec in the presence of organic materials. At 0.5X, PPMS successfully inactivated E. coli, AIV and NDV within 5 sec in the absence of organic material. However, rif-SI and SI necessitated 30 sec for inactivation. Most pathogens were inactivated within 30 sec, with the exception for AIV, which was inactivated within 5 sec. PPMS effectively eliminated rif-SI on all carriers within 30 sec. Moreover, at both concentrations, PPMS successfully inactivated AIV on all carriers within 30 sec, except on stainless steel at 0.5X. Furthermore, PPMS at both concentrations required 5 and 30 sec, respectively, to inactivate AIV on the rayon sheet. Therefore, due to its demonstrated efficacy against a wide range of pathogens across diverse surfaces, PPMS emerges as a crucial alternative disinfectant significantly enhancing biosecurity on and around chicken farms. found in and around animal farms, slaughterhouses, and hospitals.

Background and Aim: The selection and proper application of disinfectants are crucial to the prevention of many diseases, so disinfectants must be evaluated before being used for the prevention of African swine fever (ASF). Three disinfectant products belonging to the group of potassium hydrogen peroxymonosulfates, product A and product B, and a quaternary ammonium compound called product C, were examined in vitro for host cell cytotoxicity and the efficacy of ASF virus inactivation. The study parameters included various concentrations, exposure times, temperatures, and degrees of cytotoxicity. Materials and Methods: Three disinfectant products were evaluated for cytotoxicity using primary porcine alveolar macrophage (PAM) cells at dilutions from 1:200 to 1:51,200. Disinfectants in concentrations of 1:200, 1:400, and 1:800 were prepared, the pH and the virucidal activity were tested. An equal volume of each dilution was mixed with the ASF virus and incubated at room temperature (20°C) or on ice (4°C) for 1 min, 5 min, or 30 min. Hemadsorption (HAD) or rosette formation was observed using an inverted microscope for 5 days after inoculation, and the virus titer was calculated as HAD50/mL. Each treatment and virus control were tested in triplicate, and the titers were reported as means and standard deviations. The reduction factor was used to measure inactivation. Results: Products A, B, and C at 1:400, 1:800, and 1:25,600 of dilution, respectively, did not show significant cytotoxic effects on PAM cells. Products A and B could inactivate ASF virus at 1:200 dilution within 5 min after exposure at 4°C. However, at 20°C, the exposure time had to be extended to 30 min to inactivate the virus. Product C could inactivate the virus at 1:400 dilution within 5 min under both temperature conditions, whereas at 1:800 dilution, the exposure time had to be extended to 30 min to completely inactivate the virus at 20°C. Conclusion: All disinfectants could inactivate ASF virus in various concentrations, under appropriate exposure times and reaction temperatures, and there was no evidence of host cell cytotoxicity. For the control of ASF in pig farms, the appropriate concentration, ambient temperature, and contact time of these disinfectants should be taken into account.

Background and Aim: The concentration of serum progesterone is commonly used to determine the optimal mating time in bitches, and to diagnose reproductive-related abnormalities. This study aims to compare the serum progesterone results obtained by rapid fluorescence immunochromatography assay (RFICA) with those obtained by chemiluminescent microparticle immunoassay (CMIA) from the same serum samples to develop a standard guideline for optimal breeding time. Materials and Methods: Serum progesterone levels were measured in 124 bitches using RFICA and CMIA. Simple linear regression and correlation analyses were performed to analyze the data. The percentage difference between the maximum and minimum progesterone values in the same serum sample in the same assay was compared using Wilcoxon's rank-sum test. Results: The present study showed a strong linear dependence of the results obtained by RFICA on those obtained by CMIA as R2=0.8976, with regression coefficient of 0.9474 and p<0.05, including the regression model was CMIA = (0.9483 × RFICA) - 0.761. Moreover, five critical measurement times during estrous in bitches showed statistically significant differences (p0.05). Conclusion: This study demonstrated that it is presumably acceptable to use the RFICA and CMIA methods interchangeably for quality progesterone measurements in serum samples from bitches. However, when considering the use of the RFICA method, it is advisable to carefully interpret the results and follow the interpretation guidelines. Finally, RFICA in the present study provides a reliable and convenient option for veterinarian practitioners to measure canine progesterone levels in-house.

Porcine respiratory coronavirus (PRCoV) infects the epithelial cells in the respiratory tract of pigs, causing a mild respiratory disease. We applied air–liquid interface (ALI) cultures of well-differentiated porcine airway cells to mimic the respiratory tract epithelium in vitro and use it for analyzing the infection by PRCoV. As reported for most coronaviruses, virus entry and virus release occurred mainly via the apical membrane domain. A novel finding was that PRCoV preferentially targets non-ciliated and among them the non-mucus-producing cells. Aminopeptidase N (APN), the cellular receptor for PRCoV was also more abundantly expressed on this type of cell suggesting that APN is a determinant of the cell tropism. Interestingly, differentiation-dependent differences were found both in the expression of pAPN and the susceptibility to PRCoV infection. Cells in an early differentiation stage express higher levels of pAPN and are more susceptible to infection by PRCoV than are well-differentiated cells. A difference in the susceptibility to infection was also detected when tracheal and bronchial cells were compared. The increased susceptibility to infection of bronchial epithelial cells was, however, not due to an increased abundance of APN on the cell surface. Our data reveal a complex pattern of infection in porcine differentiated airway epithelial cells that could not be elucidated with immortalized cell lines. The results are expected to have relevance also for the analysis of other respiratory viruses.

Aim: The present study aimed at highlighting the effects of oyster mushroom (Pleurotus sajor-caju), as a dietary supplement on growth performance, differential leukocytes population, and histological changes of melanomacrophage centers (MMCs) in spleen and kidney of fancy carp on bacterial infection. Materials and Methods: A total of 60 fancy carp were allocated into four groups according to feed formulations including; (1) basal diet with 2% crude extract of P. sajor-caju, (2) basal diet with 2% β-glucan, whereas Group 3, and Group 4 were positive and negative control, which were fed only basal diet. Diets were provided for 30 days, thereafter, fish of Group 1 to Group 3 were intraperitoneally injected with Aeromonas veronii (1.8×109 CFU), whereas Group 4 was injected with normal saline. At day 7 post-bacterial inoculation, all fish were weighed, whole blood was collected for differential white blood cell count, and two visceral organs, posterior kidney and spleen, were collected from euthanized fish to observe histological changes, particularly MMCs. Results: No significant differences in body weight were found (p>0.05) at 1st week of the experiment; however, fish body weight was significantly increased from week 2 to week 4 of the experiment. Increased monocyte number was found in carp fish fed with the P. sajor-caju or β-glucan supplemented diets compared to the control groups (p<0.05). The proliferation of monocyte in fish was consistent with increased number and size of MMCs in hemotopoietic organs, posterior kidney and spleen, especially in fancy carp fed with of P. sajor-caju crude extract and commercially available β-glucan before bacterial inoculation in fish. Conclusion: These findings indicate that crude polysaccharide from P. sajor-caju can be potentially used as a feed additive that might promote innate immune function in fish.

Aim: This study aimed to evaluate the bactericidal and virucidal activity of food additive grade calcium hydroxide (FdCa(OH)2) under various concentrations, organic material conditions, and exposure duration including its stability. Materials and Methods: The FdCa(OH)2 powder as well as the 0.17% and 3% solutions were evaluated for bacteria and virus inactivating efficacies against Salmonella infantis (SI), Escherichia coli, Newcastle disease virus (NDV), and avian influenza virus (AIV), in the absence or presence of organic materials. In addition, the stability of FdCa(OH)2, was also examined using wet-dry conditions and under sunlight. Results: The FdCa(OH)2 powder could inactivate both NDV and AIV in the absence and presence of organic materials within a 3 min exposure period. The bactericidal efficacy using solution form revealed that 0.17% and 3% of FdCa(OH)2 could inactivate SI in the absence and presence of organic materials within 3 min of exposure. However, 3% of FdCa(OH)2 inactivated E. coli both with and without organic materials within 3min, while 0.17% required 5 min to be efficacious. The virucidal efficacy also showed that 0.17% FdCa(OH)2 could inactivate NDV in the absence and presence of organic materials within 10 min and 30 min, respectively. However, AIV inactivation was achieved within 30 sec under all conditions. In addition, under wet and dry conditions, FdCa(OH)2 powder demonstrated high efficacy when re-suspended at least 16 times for NDV and 7 times for AIV. Simultaneously, the FdCa(OH)2 powder retained its efficacy under the sunlight during up to 4 months for NDV and at least 6 months for AIV. Conclusion: The present study indicates that FdCa(OH)2 powder and solutions could inactivate SI, E. coli, NDV, and AIV while retaining good stability under challenging environmental conditions. Finally, the FdCa(OH)2 is safe for consumers because it is of food additive grade and can be useful as an alternative disinfectant, especially for biosecurity enhancement on and around poultry farms.

Aim: The present study was examined the virucidal activity comparison between fresh charcoal ash (FCA) and slaked lime (SL) against avian influenza virus (AIV) and Newcastle disease virus (NDV), using powder and liquid forms, either in the absence or presence of organic materials. In addition, both FCA and SL were evaluated for the persistence of virucidal activity in wet and dry conditions and stability of the solution. Materials and Methods: Two hundred milligrams of FCA or SL powders were mixed with 100 μl of AIV or NDV in the absence of organic material or 33% of organic materials. In the same time, 400 μl of 1%, 5%, or 10% solution samples were mixed with 100 μl of each virus and then incubated at room temperature for an indicated time. After that, the mixed solution was stop activity of sample using 500 μl of 1M Tris-HCl pH 7.2. Each treatment was titrated onto Madin-Darby canine kidney cells or chicken embryo fibroblasts for AIV or NDV, respectively, for determining the efficacy of viral inactivation. In addition, the stability of powder under the wet-dry condition and solution stability under room temperature was examined. Results: The results demonstrated that the FCA and SL in powder form could inactivate AIV and NDV even in the absence or presence of organic materials. In the liquid form, 5% and 10% of FCA could inactivate AIV and NDV either in the absence or presence of organic materials. Alongside, 1%, 5%, and 10% of SL could inactivate both viruses. 10% of FCA solution could inactivate virus at a shortest time when compared with other concentrations. In addition, the efficacy of wet-dry conditions of FCA was limited when compared with SL. On the other hand, it is demonstrated that the FCA solution was more stable and kept at room temperature longer than SL. Conclusion: The FCA may, hence, be used as an alternative virucide, while applying it to prevent spreading of poultry disease on commercial chicken farms and also backyard chickens, especially in developing countries, including in rural areas of Thailand.

This study was to determine the effectiveness of the fourth-generation quaternary ammonium compounds, didecyl dimethyl ammonium bromide (DDAB), on the efficacy of bacterial and viral decontamination against pathogens commonly found in livestock industry including Salmonella infantis (SI), Escherichia coli, and avian influenza virus