Veterinary Research Forum
Volume:16 Issue: 5, Dec 2025

Rhodococcus equi is an important bacterial pathogen and causes severe chronic granulomatous pneumonia in foals below 6 months of age. It has also become an opportunistic and emerging pathogen in immunocompromised humans. Vaccination is the most cost-effective strategy for controlling and preventing this infection. Although several potential virulence genes and candidate immunogens have been identified over the years, no effective vaccine is currently available to prevent R. equi disease in horses. Recently, bacterial vector vaccines have been shown to be promising for R. equi. In this study, the virulence-associated protein A (VapA) gene of R. equi was cloned into Protein Expression System small ubiquitin-related modifier (pET-SUMO) expression vectors and transferred into Escherichia coli BL21 (DE3). Also, adjuvant significantly affects the efficacy of recombinant vaccines. Therefore, native VapA and recombinant VapA were formulated with Immunostimuling Microparticle System (IMS 3012) or PetGel A (recommended for horses) and subcutaneously administered to mice. The immunization effect of four different vaccines was determined by assaying antibody titers and survival rates. The antibody response was slightly higher in the PetGel A formulations than IMS 3012. Survival rates were lower in the PetGel A formulations than IMS 3012. Given these results, recombinant VapA adjuvanted with PetGel A represents a promising formulation for developing new-generation R. equi vaccines.

The present study was planned to confirm the clinical diagnosis of canine distemper in dogs with reverse transcriptase polymerase chain reaction (RT-PCR) and its comparison with lateral flow assay based immuno-chromatographic (IC) technique. Fifty clients owned dogs having clinical signs suggestive of respiratory, skin or nervous form of canine distemper were included in the study. An immuno-chromatography-based test was applied using serum to screen each of the suspected dog. In addition to serum, nasal discharges of 15 cases and ocular discharges of 10 samples were used to diagnose canine distemper. Screening with IC kit revealed 72.00% serum samples positive, 66.66% ocular and 50.00% nasal samples were found positive for antigen. The RT-PCR targeting N gene of canine distemper virus was used for the molecular diagnosis of canine distemper. Out of 50 blood samples tested with RT-PCR assay, 38 (76.00%) samples were positive showing characteristics band of 287bp. Statistical comparison of IC Kit (serum samples) results with RT-PCR results comparison showed that IC kit was 52.00% accurate with 36.84% sensitivity, 100% specificity, positive predictive value of 93.33% and negative predictive value of 31.43%. In the current study it was observed that the IC test was rapid, quick and specific but was found to be less sensitive compared to RT-PCR.

Avian Salmonellosis impacts the economy and public health, with chicken products being a major cause of gastroenteritis. Hygiene, immunization and medicines are all used as control techniques. Bacteriophages provide a safe, targeted alternative. In the present study in vitro evaluation of bacteriophages were done against Salmonella typhimurium. Lytic effect of bacteriophages isolated from poultry sludge was checked on culture of S. typhimurium. Stability study was checked at range of temperature and pH. The phages were stable at temperature (30.00 - 50.00 ˚C) and pH (5.00 - 9.00) where best activity was seen at 37.00 ˚C and pH 7.00. In vitro lytic activity was done at (optical density 600 nm) after exposure to bacterial host at different intervals. Multiplicity of Infection of 1.00 was used to check lytic activity of phages which indicated phages were potent enough to infect bacterial cells within their growth cycle. The percentage of unadsorbed phages was determined by bar chart analysis. The genome of three phages was treated with DNase I where they all were sensitive. Later the nucleic acid of phages was digested by restriction endonucleases (EcoRI and HindIII) both of the enzymes produced various restriction sites with different band. The present study proved that the application of bacteriophages in vitro into bacterial system i.e., S. typhimurium was an attractive method in diminishing infection in commercial poultry thus providing exceptional results that could be used on a large scale.

Buildup of reactive oxygen species during testicular torsion causes oxidative stress and ischemia-reperfusion (I/R) injury in testis. The purpose of this study was to investigate influence of β-cryptoxanthin (BCX) on I/R injury in testicular torsion/detorsion in mature rats. Thirty mature male Wistar rats were divided into five groups of six animals each, including sham group: In this group, midline incision of the scrotum was performed and the testicles were taken out for 2 hr with a 720-degree rotation, I/R group: In this group, midline incision of the scrotum was performed and the testicles were taken out and undergone ischemia for 2 hr with a 720-degree rotation, I/R/Oil group: In this group, a midline scrotum cut was performed, the testicles were taken out, ischemia was created for 2 hr with a 720-degree rotation, and at the end of ischemia 100 µL of corn oil (BCX solvent) was injected intraperitoneally, I/R/BCX10 group: The same as I/R/Oil group, as well as intraperitoneal administration of 100 µL of BCX (10.00 µg kg-1) at the end of ischemia, and I/R/BCX40: The same as I/R/Oil group, as well as intraperitoneal administration of 100 µL of BCX (40.00 µg kg-1) at the end of ischemia. Evaluations were based on histopathological and spermatological parameters and oxidative stress assessments. Histopathological spermatological and oxidative stress parameters values obtained from I/R/BCX40 were significantly different from those of other groups (p < 0.05). It could be concluded that BCX could ameliorate testicular injuries in acute testicular torsion/detorsion in mature rats.

The aim of this study was to using purified chicken antibody (IgY) for developing solid phase competitive (SPC) enzyme-linked immunosorbent assay (ELISA) to detect the foot-and-mouth disease virus (FMDV) A serotype. After immunization of chickens, polyclonal immunoglobulin (IgY) antibodies were extracted and purified from egg yolk and yield was about 5.00 mg mL-1 of yolk as well as near 0.40 mg mL-1 of specific IgY antibody against FMDV serotype A. Also, optimized sucrose density gradient method produced 228 µg mL-1 whole virus which is much higher than that of the conventional method of sucrose density gradient method. The optimum concentration of purified capture IgY and bind type A antigen were 0.50 µg and 0.10 µg per well, respectively. The OD values < 0.70 were considered positive, and values ≥ 0.70 were negative for in-house kit base on standard controls. Statistical analysis base on 80 serum samples showed the 96.66% sensitivity, 100% specificity, 100% positive predictive value, 90.90% negative predictive value, 97.50% accuracy, and 98.33% reliability for serum samples for two commercial and in-house kits. The SPCE developed based on IgY antibody is a suitable alternative for the detection of antibodies after vaccination against type A FMDV with high sensitivity and specificity. The present research demonstrated the possibility of commercial development of the SPCE kit using IgY antibodies for the detection of FMDV antibodies in serum samples with adequate sensitivity and accuracy.

Bone structure has been widely studied in mammals, however, osteon structure in sheep has received relatively little attention, especially in terms of its location on the forelimbs and hindlimbs. The aim of this study was to investigate the histometric characteristics and mineral composition of the metacarpus and metatarsus of adult Sanjabi sheep. Metacarpal and metatarsal bones were collected from five adult Sanjabi sheep (n = 10). Morphometric measurements were performed on computed tomographic scan images. Histometric parameters were measured on histological sections. The mineral composition of the bone samples was detected using the X-ray fluorescence method. The diameter of the Haversian canal in the right metatarsus was significantly greater than that in the other bones. The smallest diameter of the Haversian canal was observed for the right metacarpus. The diameter and area of the osteons in the right metacarpal were significantly greater than those in the other bones. The amount of essential mineral elements was not significantly different among bones. Aluminum and lead were significantly greater in the left metatarsus. The highest amount of copper was observed in the left metacarpus. These results indicated that there was a greater load on the right limb. This compensatory mechanism might be used to put more weight on the right forelimb and reduce the pressure caused by the weight of the rumen on the left forelimb. However, to prove this hypothesis, more detailed and extensive studies are needed in the future.

Infectious bovine rhinotracheitis, caused by bovine herpesvirus-1 (BHV-1) is a highly contagious viral disease affecting bovines, and clinically characterized by pyrexia, inappetence, respiratory distress, dyspnoea, conjunctivitis, nasal discharge, and sometimes abortions. In the present study, buffalo dairy farm having high mortality was investigated. The buffaloes were suffering from high rectal temperature, conjunctivitis, severe respiratory distress, and nasal discharge. Tissue samples from upper respiratory tract were collected aseptically following post-mortem examination of died buffaloes. Tracheal tissue samples were then processed for histopathological examination and DNA isolation. The presence of BHV-1 in the tissue samples was confirmed by nested polymerase chain reaction using glycoprotein B gene primers. The present study reported for the first time the clinical signs, post-mortem lesions, histopathological evidence, and detection of DNA of BHV-1 glycoprotein B gene through nested polymerase chain reaction assay during an active outbreak in buffaloes in India. The findings of this study are crucial for improving the diagnosis of BHV-1 and ultimately reducing financial losses within dairy industry.

A mixed-breed 15-year-old mare was euthanized for recurrent colic, severe weight loss, pastern ulcerative dermatitis, and coronitis without response to non-surgical medical procedures. The liver was congested with firm consistency at necropsy, and there were multi-focal white spots on Glisson’s capsule. Hemorrhage, ulcer, severe folding, and hypertrophy were seen in the duodenum and jejunum. Histopathological examination showed marked infiltration of eosinophils concomitant with fewer leukocytes, macrophages, and plasma cells, primarily in the liver and intestines. The presence of eight calcium bilirubinate stones, 2.00 - 5.00 cm in diameter, in the common bile duct was characteristic of choledocholithiasis. Concurrent multi-systemic eosinophilic epitheliotropic disease (MEED) and choledocholithiasis were confirmed after ruling out other potential causes of eosinophilic infiltration, including parasitic infection and allergy. The cause of MEED and choledocholithiasis was unclear because of incomplete case history and delayed referral, with a potential infection playing a role and having synergistic effects between the two conditions. When eosinophilic-associated inflammation involves several organs, MEED should be on the differential diagnostic list since infections and allergens are also among the risk factors for this disorder.