BACKGROUND: The repetitive use of antibiotics in different fields (veterinary and medicine) improves the emergence and occurrence of the resistance phenomenon in pathogenic bacteria. Due to the problem of antimicrobial resistance, it is an urgent need to discover new drugs and alternative treatments for the control of bacterial diseases in aquaculture. OBJECTIVES: The purpose of this study is to investigate antibacterial effects of methanol and hexane extracts of medicinal plants Rattles (Prosopis farcta), datura (Datura stramunium L) and milkweed (Calotropis procera L), the major pathogenic bacteria of fish, including Aeromonas hydrophila, Yersinia ruckeri and Streptococcus iniae. METHODS: Extraction was performed using a rotary evaporator. To determine the minimum inhibitory concentration (MIC), the standard microdilution method (Dilution in broth) was used and the minimum bactericidal concentration (MBC) was determined based on MIC values obtained for each extract. RESULTS: The results showed that the effect of most potent extract, methanol extract obtained from fruit rattle on the three studied bacteria, with MIC and MBC are 25, 50mg/ml, respectively. The most sensitive bacteria to methanol and hexane plant extracts, is bacterium Streptococcus iniae and Aeromonas hydrophila and Yersiniaruckeri bacteria were resistant. The studied extracts had stronger antibacterial properties against gram-positive bacteria compared to gram-negative. CONCLUSIONS: According to the results, it seems that the use of methanol extract of Prosopis farcta fruit is effective for treatment of bacterial diseases in aquaculture.

BACKGROUND: Pre-purchase radiographic examinations of horses are very important for the diagnosis of possible disorders.OBJECTIVES: This study aims to determine the variation and frequency of common disorders of the tarsus in pre-purchase radiographic examinations of horses and assess the effect of age, sex, and type of hind limb (right or left) on the occurrence of these disorders.METHODS: In this study, we used the radiographs taken from the tarsal joints of the right and left hind limbs in 110 horses for a two-year period which were requested for pre-purchase radiographic examinations. Among these radiographs, the cases that included the standard position of the tarsal joint were evaluated for the existing disorders and the effect of age, sex, and type of involved hind limb.RESULTS: The most frequent disorders were osteoarthrosis (32.27 %), osteochondritis dissecans (5.91 %), and soft tissue swelling (1.36 %). The least common disorders were calcification, desmopathy, and tenosynovitis, each with a prevalence of 0.45%. Also, most of the tarsal ​​joint disorders had a mild degree of severity (80 %). The prevalence of disorders was 100 % for horses aged <4 years (4 out of 4) and 49.1 % for horses aged >4 years (52 out of 106). No significant difference was observed in terms of gender (P=0.65) and type of involved hind limb (P=0.17).CONCLUSIONS: Considering the prevalence of tarsal joint disorders in horses, pre-purchase radiographic examination can be very important for predicting the future health and performance of the horse. Therefore, radiographic evaluation of the tarsal joint should always be a part of pre-purchase examinations in horses.

BACKGROUND: In free stalls, factors related to the surface and dimensions of the stall affect how the cows rest and comfort. The brisket board and the neck rail are the most controversial parts of the free stall in Iran's dairy farms, that can affect the stability of the stall and its lifespan, while improper use of these structures has led to significant discomfort for cows, causing substantial issues including lameness and hock, knee and withers lesions.OBJECTIVES: This study aims to investigate Brisket boards and neck rails usage and measures in freestall barns and assess its possible impact on some comfort indices in dairy cows.METHODS: Nine dairy farms with over 100 milk cows and freestall barns were selected using the Dairy Farmers of Canada protocols by a convenience sampling method. Horizontal, vertical, and diagonal distances of the neck rail, the presence or absence of brisket boards, and the brisket board height from the bedding were measured. The locomotion score based on a five-point scale as well as hygiene, knees, hocks, and withers scores were recorded. The correlation was evaluated using the Spearman correlation test and Pearson’s correlation test.RESULTS: In 68.3 % of the freestall barns, the brisket boards were at the bedding level or were not used at all; however, the mean brisket board height (11.2±10.8) was not significantly different from the standard height value of 10 cm (P>0.05). The vertical distance of the neck rail (120.4±10.4 cm) was significantly different from the standard values. The median of withers and locomotion scores were consistent among all farms. At the farm level, the median knee, hygiene, and hock scores did not show a significant correlation with the mean of neck rail measures and brisket board height (P>0.05). Also, the median locomotion score did not show a significant correlation with the mean horizontal distance of the neck rail at the individual freestall barn level (P>0.05). However, a significant correlation between the mean of knee scores and vertical distance of the neck rail at the farm level, and between the mean of locomotion score and horizontal distance of the neck rail at the individual freestall barn level were reported.CONCLUSIONS: An increase in the mean vertical distance of the neck rail is associated with an increase in the median knee scores, while an increase in the mean horizontal distance in each barn was associated with an increase in the median locomotion score, indicating the potential impact of these measurements on cow comfort. However, further research using a larger sample size is needed.

BACKGROUND: Horses are economically and emotionally valuable animals in various activities, especially sports. Thus, paying attention to their limb's health and conformation is vital. One of the most common diseases in the limbs of horses is laminitis. Horses with this condition suffer from lameness because it affects laminar tissue. In addition to clinical signs, radiographic criteria are essential for identifying this disease.OBJECTIVES: It is predicted that examining the effectiveness of quantitative radiographic criteria of the hoof can be helpful in the diagnosis of laminitis. Therefore, in this study, five quantitatively effective factors were investigated before and after hoof trimming to determine the changes in the radiographic diagnosis of laminitis.METHODS: A total of 11 clinically healthy horses were used in the current study. Using Marco DICOM Viewer software, lateral and dorsopalmar radiographs from the hoofs of both forelimbs were evaluated for the diagnosis of laminitis using effective quantitative criteria. Using SPSS version 24, paired T-tests were used to analyze quantitative data. P≤0.05 was considered significant.RESULTS: According to the results of this study, there were no significant differences between the right and left forelimbs after hoof trimming. On the other hand, significant differences were observed in the four following criteria: dorsal thickness between the dorsal surface of the third phalanx and the dorsal surface of the hoof, the angle between the dorsal surface of the third phalanx and the dorsal surface of the hoof, sole thickness, and the ratio of the third phalanx dorsal surface thickness to its maximum length in each forelimb before and after hoof trimming.CONCLUSIONS: During the radiographic examination, the hoof should be positioned in a standard way to diagnose laminitis accurately. However, if the hoof is not trimmed or not trimmed properly, it can interfere with laminitis diagnosis.

BACKGROUND: Coronaviruses, which mainly cause gastrointestinal and respiratory infections, have been identified in various species. Among the extensive genomic data of disease-causing Coronaviruses in humans and animals, some similarities can be analyzed by in-silico methods.   OBJECTIVES: In the present study, comparative genome analysis of medical and veterinary medicine Coronaviruses was performed to obtain more accurate information about the genetic similarities and differences of different members of this family.METHODS: The genomic sequences were retrieved from NCBI and Virus Pathogen Resource databases. Using the NCBI database blast algorithm, all sequences were aligned with the SARS-CoV-2 genome sequence, and similarity was obtained. Amino acid sequences of structural and non-structural proteins associated with coding regions (CDS) were aligned separately with the SARS-CoV-2, and their similarities were calculated. The 3D structure from each protein was compared with the corresponding protein in SARS-CoV-2, and Template Modeling Scores (TM-Score) were obtained. A phylogenetic tree of different species of the Coronaviridae family was drawn based on nucleotide and amino acid sequence data.RESULTS: Nonstructural coding gene sequences detected the highest interspecies similarities in nucleotide, amino acid sequence, and 3D structure (nsp12, nsp13, nsp14, and nsp16). The ORF1ab, encoding non-structural proteins, carries essential functions for viral replication.CONCLUSIONS: This study showed that the transcription complex is highly conserved among human and animal Coronaviruses. A comparison and analysis of the Coronaviridae transcription complex can be considered a key target for diagnosing, developing antiviral therapies, and designing vaccines.

BACKGROUND: Infectious diseases and microbial antibiotic resistance are the major problems of fish farming industry annually causing remarkable losses. Apart from the economic losses caused by these infections, some of these agents are zoonotic and may be transmitted to humans.OBJECTIVES: This study was aimed to identify the common causative agents of infections in rainbow trout farms and to determine their antibiotic resistance toward some common antibiotics.METHODS: Sampling was performed during a nine-month period between March and December 2021 by visiting and inspecting rainbow trout farms and the affected fish with disease symptoms were obtained from the farmed fish in Mazandaran, Lorestan, Chaharmahal and Bakhtiari and Zanjan provinces. Bacterial culture was undertaken from anterior kidney or spleen organs and the isolated bacterial strains were identified by phenotyping, biochemical and molecular assays. Antibiotic resistance pattern was evaluated by disk diffusion method (DDM) and minimum inhibition concentration against erythromycin, oxytetracycline, florfenicol, enrofloxacin and nitrofurantoin.RESULTS: Seventy-four bacterial isolates of Gram-positive cocci or Gram-negative coccobacilli were isolated. In phenotyping, biochemical and molecular (PCR) assays Lactococcus garvieae (12 isolates, 16.2 %), Aeromonas hydrophila (9 isolates, 12.2 %), Streptococcus iniae (17 isolates, 23 %), Streptococcus agalactiae (20 isolates, 27 %), and Yersinia ruckeri (16 isolates, 21.7 %) were identified. The majority of these isolates were obtained from the fish farms in Mazandaran province. Erythromycin and oxytetracycline with 87.8 % resistance were antibiotics with the highest resistance, while enrofloxacin with 24.3 % resistance revealed the lowest level of resistance. Antibiotic resistance rates for florfenicol and nitrofurantoin were also 43.2 % and 44.4 %, respectively. The highest antibiotic resistance was detected in the bacterial isolates of Lactococcus garvieae, Aeromonas hydrophila, Streptococcus iniae, Streptococcus agalactiae and Yersinia ruckeri, respectively.CONCLUSIONS: This study shows that the spread of streptococcosis, lactococcosis, yersiniasis and Aeromonas septicemia and their frequent treatments has led to an increase in antibiotic resistance, especially against commonly used drugs such as erythromycin and oxytetracycline.

BACKGROUND: Respiratory pathogenic beta-hemolytic streptococci in horses, including Streptococcus equi subsp. equi, the causative agent of strangles disease, Streptococcus equi subsp. zooepidemicus is an important cause of respiratory disease and Streptococcus dysgalactiae subsp. equisimilis has been isolated from nasal swabs taken from horses with a history of respiratory disease.OBJECTIVES: The present study aimed to determine the frequency and risk factors of respiratory tract infections originating from beta-hemolytic streptococci in the provinces of West Azerbaijan, East Azerbaijan, and Ardabil.METHODS: During this study, 121 horses with clinical respiratory symptoms were sampled. After performing clinical examinations and recording clinical signs in special worksheets, sampling of the upper part of the respiratory tract was performed using nasopharyngeal swabs. The samples were sent to the laboratory in a standard transfer medium with cold chain.RESULTS: In this study, out of 121 samples collected from horse breeding clubs from 10 different regions of northwestern Iran, 51 were negative for beta-hemolytic streptococci while the results were positive for the other 70 samples (P<0.001). Regarding the positive samples for beta-hemolytic streptococci, the results of differential cultures were as follows: eight cases of Streptococcus equi subsp. equi, 57 cases of Streptococcus equi subsp. zooepidemicus, and five cases of Streptococcus dysgalactiae subsp. equisimilis. There was no significant relationship between the frequency of beta-hemolytic infections with variables of gender, race, and geographical area (P>0.05). Meanwhile, the statistical test showed a significant relationship between the frequency of infection with these bacteria and the variable of clinical symptoms (P<0.001). Moreover, the frequency of beta-hemolytic streptococcal infections was significantly associated with age (P<0.05).CONCLUSIONS: The results herein suggested that the bacterial cause of the majority of respiratory infections in infected and sampled horses in the provinces of West Azerbaijan, East Azerbaijan, and Ardabil at the time of sampling was Streptococcus equi subsp. zooepidemicus and that this organism is a potential pathogen for respiratory diseases in horses in these provinces.

BACKGROUND: Toxocara canis C-type lectin (T. canis-CTL) is the main protein part of the secretory-excretory product secreted by Toxocara canis infective larvae. T. canis-CTL can stimulate immune response-mediated regulatory T lymphocytes, increase the FOXP3+ cells population, and reduce severe inflammatory responses. T. canis-CTL is a promising candidate for immune modulation in some autoimmune diseases, deserving further investigation.OBJECTIVES: The current research aimed to purify the recombinant T. canis-CTL under denaturation and native condition to increase exploration and maintain biological activity.METHODS: The expression vector, pET32a was constructed with the partial sequence 660bp of T. canis-CTL and expressed in E. coli BL21 (DE3). T. canis-CTL protein expression was induced by IPTG (1 mM) at 37°C after 6 h. In this study, different buffers were used for cell explosion and recombinant protein solubilization, including lysis buffer with urea (8 M, pH=8) and lysozyme enzyme as well as lysis buffer with Imidazole (0.01 M) and lysozyme enzyme, and previous buffers in addition to sonication. The effect of these buffers was evaluated in bacterial cells explosion, using Gram-staining and microscopic examination. Recombinant T. canis-CTL protein was extracted and purified under denaturation and native condition using Ni-NTA affinity chromatography by agarose and sepharose resin. A New Zealand male rabbit was immunized with the recombinant protein to evaluate the bioactivity of the protein. RESULTS: Lysis buffer with urea (8 M, pH=8) and lysozyme enzyme, in addition to sonication, provided acceptable results, and an additional amount of recombinant T. canis-CTL protein was secreted in the buffer. Protein purification under denaturation conditions with Ni-NTA agarose affinity chromatography also provides further recombinant protein. Most of the induction of recombinant T. canis-CTL with 41 KDa molecular weight was collected 6 h after induction at 37°C. Dot-blot results illustrate the brown dot, which showed a 1:500 titer of specific IgG polyclonal antibody has developed in the sera of rabbits immunized with T. canis-CTL recombinant protein.CONCLUSIONS: The denaturation condition did not affect the biological activity of the T. canis-CTL recombinant protein and can recover a further amount of recombinant proteins.

BACKGROUND: Lyme disease is caused by a gram-negative spirochete bacterium called “Borrelia burgdorferi” and can be transmitted by the bite of infected ticks to humans and animals. This disease has a global geographic distribution Dogs can be infected by the bite of the Ixodes ricinus tick.OBJECTIVES: This study aims to detect the prevalence of Borrelia burgdorferi in guard dogs in Isfahan, Iran.METHODS: In this study, blood samples were collected from 97 guard dogs with an average age of 3.5 years in Isfahan city and analyzed by the blood smear method and the nested polymerase chain reaction method (molecular study). The data were statistically analyzed in SPSS software (version 24) using Fisher's exact test and chi square.RESULTS: Twelve samples (12.37 %) were found molecularly positive, which were for 10 male dogs (10.30 %) and two female dogs (2.06 %). There was no evidence of the presence of bacteria in the blood smear and hematological changes were not found in complete blood count tests (CBC Test) performed on infected samples. There was a significant difference in the levels of infection between the age groups of 1 to 2 years (P=0.029) and between this age group (1 to 2 years) and the age group >3 years (P=0.032. (There was a significant difference in infection levels between dogs with different gender.CONCLUSIONS: The prevalence of Borrelia burgdorferi in dogs of Isfahan City is relatively high. Due to the ease of transmission of this pathogen between humans and animals, special attention should be paid for its control and timely detection.

BACKGROUND: Numerous studies have investigated the positive effect of chitosan and nano-chitosan loaded clinoptilolite on growth performance, digestive enzyme activity, and intestinal histomorphology in different fish species. However, there are no data evaluating the potential effect of the composites on the fish stomach.OBJECTIVES: In the current study, the effects of chitosan and nano-chitosan loaded clinoptilolite on histological features and pepsin activity in the rainbow trout stomach were considered.METHODS: Chitosan and nano-chitosan loaded clinoptilolite were synthesized, and then two hundred and forty fish (~27.75 g) fish were distributed in eight groups each in three replicates. Ten days after adaptation, the fish were fed with eight diets, including control diet (CTR), clinpotilolite (T1), chitosan composites (T2, T3, T4), and nano-chitosan composites (T5, T6, T7) for 70 days. Afterward, all fish in each tank were anesthetized in clove extract (50 μl/l), and tissue samples were obtained for pepsin activity (n= 5) and histological assay (n = 5).RESULTS: The groups administrated with nanochitosan composites showed the highest pepsin activity (P˂0.05). Additionally, histological examinations exhibited a higher epithelial height, increased mucosal density, and oxynticopeptic cells hypertrophy in fish fed composites compared to the CTR group (P˂0.05). Meanwhile, nanochitosan composite administration could cause higher reaction of secreted granules to periodic acid–Schiff (PAS) staining.CONCLUSIONS: The findings demonstrated the potential application of chitosan and nano-chitosan loaded clinoptilolite composites for improvements in the histomorphology and pepsin activity of the rainbow trout stomach, resulting in higher growth performance.