Persistence of passive immunity in calves receiving colostrum from cows vaccinated with a live attenuated lumpy skin disease vaccine and the performance of serological tests

This study aimed to determine the persistent duration of maternal immunity against lumpy skin disease virus (LSDV) in dairy calves born from vaccinated cows using a virus neutralization test (VNT). The performance of the VNT and an in-house-ELISA test was also determined. Thirty-seven pregnant cows from 12 LSD-free dairy farms in Lamphun province, Thailand were immunized with a homologous Neethling strain-based attenuated vaccine and calved from December 2021 to April 2022. Blood samples from dam-calve pairs were collected within the first week after calving. Subsequently, blood samples were taken from the calves at monthly intervals over a period of 4 months and tested for the humoral immune response using a VNT. The calf sera were also tested with an in-house ELISA test to estimate the accuracy of both tests using a Bayesian approach. For the results, antibodies against LSDV can persist in cows for 4–9 months post-vaccination. Moreover, neutralizing antibodies and LSDV-specific antibodies against LSDV were detected in the majority of calves (75.68%) during the first week after colostrum intake. However, the percentage of seropositive calves declined to zero by day 120, with seropositivity dropping below 50% after day 60. Only a small number of seropositive calves (approximately 13.51%) were observed on day 90. These findings indicated that passive immunity against LSDV can last up to 3 months. The median of posterior estimates for sensitivity (Se) and specificity (Sp) of the VNT were 87.3% [95% posterior probability interval (PPI) = 81.1–92.2%] and 94.5% (95% PPI = 87.7–98.3%), respectively. The estimated Se and Sp for the ELISA test were 83.1% (95% PPI = 73.6–92.6%) and 94.7% (95% PPI = 88.4–98.5%), respectively. In conclusion, this study illustrates the transfer and persistence of maternal passive immunity against LSDV to calves under field conditions. This highlights a potential three-month vaccination gap in calves born from vaccinated cows, while an in-house ELISA test can be used as an ancillary test for LSDV immune response detection. However, further research is required to assess the vaccination protocols for calves as young as 2 months old to precisely determine the duration of maternal immunity

An ELISA test using a circulating Mycobacterium bovis peptide for detecting bovine tuberculosis in dairy cattle

This study aimed to determine the sensitivity (Se) and specificity (Sp) of a circulating pathogen-specific biomarker (polyketide synthetase 5, Pks5)-based enzyme-linked immunosorbent assay (ELISA) independently or in conjunction with a caudal fold tuberculin (CFT) test for bovine tuberculosis (bTB) screening in dairy cattle. We enrolled 987 dairy cows from 34 herds in Chiang Mai province, Thailand. A conditionally independent Bayesian model with a single population was inferred from the test results. The percentage of positive results for the Pks5-ELISA using 0.4 OD cutoff test and CFT test were 9.0% (89/987) and 10.5% (104/987), respectively. The median of posterior estimates of Se for the Pks5-ELISA test was 90.2% (95% posterior probability interval [PPI] = 76.6–97.4%), while the estimated Sp was slightly higher (median = 92.9, 95% PPI = 91.0–94.5%). The median estimated Se of the CFT test was 85.9% (95% PPI = 72.4–94.6%), while the estimated Sp was higher, with a median of 90.7% (95% PPI = 88.7–92.5%). The posterior estimate for true disease prevalence was 2.4% (95% PPI = 1.2–3.9%). The Pks5-ELISA test yielded characteristics at or above the acceptable standards for bTB detection. Therefore, the pathogen-specific biomarker, Pks5, is a potential detection system for bTB screening and may be applied as an ancillary test together with the currently applied standard method (CFT test) to reinforce the bTB control and eradication programs

A retrospective study of suspected pyometra causing systemic illness in 348 dogs

A retrospective study was used to investigate the prevalence, mortality rate, treatment outcomes, risk factors for death, and accompanying costs for canine pyometra cases reported in 2016 to 2018 from a single vet teaching hospital in Thailand. The prevalence of canine pyometra was 375 cases from 35,138 of canine outpatients (1.07%) with 348 cases undergoing surgery at the hospital. Mongrel dogs were most affected (37.33%) followed by Poodles (14.67%) and Shih Tzus (12.27%). The median age of pyometra cases was 7 years (range of 11 months to 16 years). The mortality rate was 10.63 % (37/ 348 dogs). Mortalities occurred in 3 dogs prior to surgery. Post-operative mortalities were reported in 24 dogs, and 10 dogs with undefined time periods. The main contributing mortality factor was uterine rupture (adjusted OR 7.38 (95% CI =2.73,19.93)). The cost of hospital treatment per case ranged between 93 to 939 United States Dollars. Surgical ovariohysterectomy is an effective treatment and preventative procedure for pyometra. Comprehensive and careful pre-operative and sufficient post-operative planning is recommended to improve treatment outcomes

Susceptibility of Clostridium difficile Isolated from Healthy Captive Asian Elephants to Metronidazole and Vancomycin บทคั ดย่ อ ความไวรั บของเชื ้ อ Clostridium difficile ที ่ คั ดแยกได้ จากช้ างเลี ้ ยงเอเชี ยต่ อยาเมทโทรนิ ดาโซล และแวนโคมั ยซิ น ณั ฐวุ

Abstract Susceptibility to metronidazole and vancomycin, drugs of choice for Clostridium difficile infection, of 15 C. difficile isolates from 6 healthy Asian elephants was determined. All of the isolates belonged to only 1 ribotype pattern and carried both toxin A and B genes. The Minimal inhibitory concentration range of metronidazole and vancomycin, drugs of choice for treatment of C. difficile infection, was 0.125-4.0 µg/ml and 0.125-2.0 µg/ml, respectively. Moreover, MIC 50 and MIC 90 for metronidazole were 0.75 and 1.5 µg/ml while vancomycin was 1.0 and 2.0 µg/ml. There was no evidence of resistance to these antimicrobials. These results might be a preliminary data for further study of animal C. difficile. Keyword

Validation of a Novel ELISA for the Diagnosis of Hemorrhagic Septicemia in Dairy Cattle from Thailand Using a Bayesian Approach

The objective of this study was to estimate sensitivity (Se) and specificity (Sp) of a novel enzyme-linked immunosorbent assay (ELISA) test (using a coating antigen from Pasteurella multocida M-1404 via heat extraction) and an indirect hemagglutination (IHA) test for detection of Hemorrhagic septicemia (HS) in dairy cows, under Thai conditions, using a Bayesian approach. Dairy cow sera with a total of 1236 samples from 44 farms were tested with the two tests to detect immune responses against the HS. Percentages of positive samples for the ELISA and IHA tests were 73% (901/1236) and 70% (860/1236), respectively. Estimated sensitivity and estimated specificity of the ELISA test were 90.5% (95% posterior probability interval (PPI) = 83.2–95.4%) and 70.8% (95% PPI = 60.8–79.8%), respectively. Additionally, estimates for the Se and Sp values of the IHA test were 77.0% (95% PPI = 70.8–84.1%) and 51.1% (PPI = 36.8–66.3%), respectively. The estimated prevalence of the disease was 71.7% (95% PPI = 62.7–82.6%). These results demonstrate that the ELISA test can be a useful tool for the detection of the presence of an antibody against the HS in dairy cows. Notably, the cows in this area indicated a high percentage of exposure to Pasteurella multocida

Protection against Pasteurella multocida conferred by an intranasal fowl cholera vaccine in Khaki Campbell ducks

Fowl cholera affects the poultry farming including ducks. The commercial fowl cholera vaccines using parenteral administration are available. Recently, an intranasal fowl cholera vaccines have been developed and tested in layers. This study, we analyzed the biological function of recombinant outer membrane protein H (rOmpH) of Pasteurella multocida strain X-73 and its antiserum. In addition, we also evaluated the protective efficacy in Khaki Campbell ducks. An adhesion inhibition assay on duck embryo fibroblast (DEF) cells was performed demonstrating that rOmpH-immunized duck sera had a potential inhibitory effect on adhesion ability of bacterial strain. An intranasal fowl cholera vaccine was formulated containing 100 μg rOmpH and 3 μg E. coli enterotoxin B (LTB) as an adjuvant. Ducks were intranasally immunized three times at three-week intervals. Challenge exposure was conducted by inoculation at 3.5 × 103 CFU/ml of a strain of X-73 at four weeks after the last immunization. Sera IgY and secretory IgA antibody titers were significantly increased (P ＜ 0.05) post immunization. Lymphocytes from ducks immunized with the rOmpH-LTB-based intranasal vaccine showed higher proliferative response to P. multocida antigens than those from ducks immunized with only rOmpH or LTB (P ＜ 0.05). Protection conferred by immunization with an intranasal or bacterin vaccine in ducks against challenge-exposure were 90% and 80%, respectively. We conclude that the intranasal fowl cholera vaccine protected ducks from artificial P. multocida infection. However, the rOmpH will be formulated with the commercial adjuvant and will be conducted against more P. multocida field strains in the duck flocks

A Preliminary Study of the Cross-Reactivity of Canine MAGE-A with Hominid Monoclonal Antibody 6C1 in Canine Mammary Gland Tumors: An Attractive Target for Cancer Diagnostic, Prognostic and Immunotherapeutic Development in Dogs

Melanoma-associated antigen-A (MAGE-A), a family of cancer/testis antigens, has been recognized as a potential target molecule for cancer immunotherapy. However, there has been very little information available with regard to this antigen in dogs. This study aimed to investigate the expression of MAGE-A in canine mammary gland tumors (CMTs) using immunohistochemistry and immunoblotting with human monoclonal MAGE-A antibody 6C1. The present study has provided evidence of cross-reactivity of the canine MAGE-A expression with the human MAGE-A antibody in CMTs. The MAGE-A antigens were expressed in moderate- and high-grade malignant CMTs (22.22%, 2/9), but no expression was observed in benign CMTs. The immunohistochemical staining of canine MAGE antigen in CMT cells showed nuclear and nuclear–cytoplasmic expression patterns that may be involved with the mitotic cell division of tumor cells. Molecular weights of the canine MAGE-A antigen presented in this study were approximately 42–62 kDa, which were close to those of other previous studies involving humans and dogs. The findings on this protein in CMTs could supply valuable oncological knowledge for the development of novel diagnostic, prognostic and immunotherapeutic tumor markers in veterinary medicine