BACKGROUND: Avian infectious bronchitis virus (IBV) has a great potential for genetic variability which leads to the generation of new virus strains. The changes in the IBV genome often cause alterations in virulence, tissue tropism, and viral replication in the host tissues.OBJECTIVES: This study was conducted to identify the virus variant strains in the trachea, lungs, and kidneys of infected birds. The possible relationship of IBV variants with the relative quantity of virus in each organ was also investigated.METHODS: The IBV variant strains were detected by polymerase chain reaction (PCR) and direct sequencing. Amongst infected commercial broiler flocks sampled at Golestan and Mazandaran provinces of Iran, nine flocks (three flocks per variant) were selected based on the identified variants. Trachea, lung, and kidney samples of five birds per flock were examined for the presence of the virus and variants. Moreover, the virus was quantified in target organs using real-time quantitative PCR.RESULTS: Based on the results of PCR and sequencing, three IBV variants were selected, namely A, B, and C. Virus types A and B were detected in all target organs, while type C was detected in the trachea and kidney. Virus type C had the highest quantity of 17.02±5.22 and virus type A showed the lowest quantity of 5.68±2.4 in infected tissues. The relative quantity of virus detected in tissues significantly correlated with the IBV variant.CONCLUSIONS: Genetic polymorphism in IBV field strains was revealed to have significant correlations with viral quantity in the lung, trachea, and kidney. Our findings are an update of the current knowledge on the associa-tions between viral genotype, virulence, and pathogenicity.

BACKGROUND: The severity of congenital heart disease can range from trivial to life-threatening conditions, and clinical signs might have no specific manifestation prior to sudden death. Radiographic and echocardiographic examinations of all kittens early in their lives are advisable due to the difficulties of diagnosis based on physical examination alone. OBJECTIVES: The current study aimed to evaluate echocardiographic and radiographic findings in a group of cats with atrial septal defect (ASD) and compare their LV-study with another group of cats with normal cardiac indices. METHODS: In the group of cats with ASD, medical records were reviewed for signalment, clinical findings, and echocardiographic data, as well as measurements in B-mode, M-mode, and color Doppler. In the normal heart group, all radiographic and echocardiographic findings were normal and echocardiographic data were compared with the same data in the group of cats with ASD. RESULTS: We found that the shunt direction in all cats with ASD was left-to-right. The mean left atrial (LA)/aortic diameter (Ao) and IVSd were the only two LV-study parameters that were significantly higher in the group of patients than the control group. However, other LV-study parameters showed non-significant differences between these two groups. The mean IVSs, EF%, and FS% in the patients were higher than the control group, while the mean LVIDs in the group of patients was lower than the control group and the mean LVIDd, LVPWd, and LVPWs were almost the same in the two groups. CONCLUSIONS: The results of this study showed that despite the defect in the interatrial septum of the patients, most of their left ventricular echocardiographic parameters showed no significant differences with normal refer-ences.

BACKGROUND: Oxaliplatin (OX) is the third-generation platinum anticancer drug used to treat various types of cancers. Although oxaliplatin has a renal metabolism, the evaluation of its nephrotoxicity is limited. OBJECTIVES: This study describes the morphometry of mouse kidneys using stereology following OX treatment. METHODS: Twenty Balb/C healthy male adult mice were divided into two groups. The mice from group 1 re-ceived 3 mg/kg oxaliplatin three times a week for 21 days, and in group 2 the mice were injected with saline. The left kidneys were used to measure the kidney volume, the volume fraction of cortex and medulla, glomerular vol-ume, glomerular mean volume, glomerular number, epithelial volume, and length of the proximal (PCT) and distal (DCT) convoluted tubules. RESULTS: No significant differences in total kidney volume, the volume of cortex, and medulla were observed between control and experimental animals (P≥0.05). No differences were observed in either epithelial volume of PCT and DCT or total length of PCT and DCT between the control and experimental group (P≥0.05). The glomer-ular volume fraction, total glomerular volume, mean glomerular volume, and glomerular number did not differ between control and the treated animals (P≥0.05). CONCLUSIONS: The results did not demonstrate any deleterious effect of OX in the mentioned dose on kidney structure in mice. These findings may help infer contradictory outcomes of different studies in this field and promote future investigations.

BACKGROUND: Mastitis is an important disease that affects dairy herds worldwide. The Staphylococcus aureus (S. aureus) is the causative pathogen for mastitis. This pathogen has the tendency to biofilm forming, and may happen to antibiotic resistance. OBJECTIVES: The aim of this study was to characterize the biofilm formation of different genotypes and antibiotic resistance pattern of S. aureus isolated from the subclinical bovine mastitis in Tehran province. METHODS: The lactating dairy cows were screened for the subclinical mastitis. The isolates were identified by phenotypic method and the presence of the nuc gene. The biofilm forming and quantification was characterized using colorimetric assay. The S. aureus biofilm gene was evaluated using PCR assay. The antimicrobial susceptibility of the isolates was assessed using DAD method. The lowest antimicrobial concentration preventing the visible growth was construed by MIC50. The antibiotic susceptibility and MBECs for the bacteria embedded in the biofilms were determined by XTT method. RESULTS: The antimicrobials susceptibility test showed penicillin and ceftiofur to be less and more effective in vitro, respec-tively. The genotypic characterization showed that the highest and the lowest frequencies for icaD (75%) and fnbB (31.2%) genes, respectively. The biofilm formation was also characterized. The MBEC results for the bacterial biofilm showed resistance to ceftiofur in the biofilm state; however, these strains were susceptible to this agent in the planktonic state. CONCLUSIONS: The biofilm formation is a significant virulence factor that was detected at a high rate. It is antibiotic-resistant and responsible for the subclinical bovine mastitis that does not respond to the routine treatments.In order to control the infection achieve the effective treatment, and prevent the emergence of antibiotic-resistant bacteria, it is necessary to isolate the causative agent and determine the antimicrobial susceptibility

BACKGROUND: Prototheca spp. belongs to the family Chlorellaceae and can cause mastitis in dairy cattle herds. Several Prototheca species could be isolated in different parts of the dairy herds. OBJECTIVES: The objectives were to determine: (1) the investigation status of bulk milk tank Prototheca Spp prevalence in industrial dairy cattle herds in different area of Iran. And (2). To evaluate the fungal agent prevalence of bulk milk tank of dairy cattle herds in different seasons. METHODS: Bulk milk tank for the presence of Prototheca and fungal agents from 165 industrial dairy cattle herds complexes were tested. The population of each herd was about 850–3500 Holstein dairy cows. The samples were taken from 32 cities and 16 provinces of Iran, respectively. In total, almost 66800 Holstein dairy cows were repre-sented. The population of lactating cows included about 25800. Samples were cultured on sabouraud glucose agar (SGA) medium with chloramphenicol (100 mg/L). RESULTS: Only 8 (4.84%) out of 165 samples were isolated for Prototheca spp. It had been isolated in different seasons. They were 2, 4, 1, and 1 samples in spring, summer, autumn and winter, respectively. Candida, Fusarium, and Trichosporon spp. were isolated from 137, 2 and 1 samples, respectively. According to the obtained results, Prototheca and fungal agents are present in bulk milk tanks of industrial dairy cattle herds in different provinces of Iran. CONCLUSIONS: It is concluded that exposure to Prototheca and different fungal agents could be common in the dairy cattle herds in Iran. The results are important as dairy cattle health and human sanitation hazar

BACKGROUND: Epididymal sperm collection is allowed by using genetic material post-mortem or after orchiec-tomy from high-value animals or endangered species. OBJECTIVES: The aim of this study was to improve the accessibility of the dog epididymal sperm cryopreserva-tion system based on the appropriate dose of lecithin. METHODS: Epididymal sperm from castrated testes of mature healthy dogs in veterinary centers were collected and divided into six groups: G1: egg yolk 20% (control), G2: lecithin 0.4% (L0.4), G3: lecithin 0.8% (L0.8), G4: lecithin 1.2% (L1.2), G5: lecithin 1.6% (L1.6), and G6: lecithin 2% (L2). Evaluation of Spermatozoa was done before freezing by Motility test, Eosin- Nigrosin vital staining and Hypo-Osmotic Swelling Test (HOST) and after thawing by Computer Assisted Semen Analysis (CASA), HOST, Eosin-Nigrosin vital staining, Mitochondrial Membrane Potential (MMP) and Intracellular Reactive Oxygen Species (ROS). RESULTS: In frozen samples, total motility and proportion of sperm with intact plasma membrane integrity based on the HOS test were lesser in all groups treated with different concentrations of lecithin than in the control group (P≤0.05). However, beat cross frequency (BCF) was higher in all groups treated with different concentrations of lecithin as compared with the control group (P≤0.05). Yet progressive motility, the proportion of live sperm based on the Eosin- Nigrosin test, VAP, VSL, VCL, STR, LIN, and ALH did not differ among various experimental groups (P>0.05). The proportion of sperm with morphological defects did not differ between fresh and frozen sam-ples and among various experimental groups (P>0.05). Mitochondrial membrane potential was greater in the control group than 0.4% lecithin group (P=0.026). The proportion of sperm positive for ROS was lesser in the control group than 0.4% lecithin group (P=0.049).

BACKGROUND: The high potential toxicity of epsilon toxin (Etx) produced by Clostridium perfringens (C. perfringens) type D, has made it the third most lethal clostridial toxin behind botulinum and tetanus, therefore, having a pure and concentrated Etx is very important. OBJECTIVES: The aim of this study was to purify Etx as pure as possible with an applicable, cost-effective, multistep purification protocol with the lowest and shortest time. METHODS: The purification of the Etx was carried out in multiple consecutive steps; ammonium sulfate precipi-tation, dialysis, size exclusion chromatography by G50, two concentration steps, and ultrafiltration. The Etx activity after different steps was evaluated by the minimum lethal dose (MLD) calculation, according to the standard oper-ating procedure. Toxin quantification was determined using Lowry technique, and its presence and specificity was tracked to identify pure Etx by SDS- PAGE and western blotting. Finally, the purity of Etx was evaluated by capil-lary electrophoresis. RESULTS: The purified Etx formed a single band of about 32.9 kDa in SDS-PAGE and blotting. The pure Etx concentration was calculated to be 3.9 mg/ml and its MLD value was the dilution of 1/24000 after the ultrafiltration step. The presented purification processes to purify Etx resulted in ~ 87-fold concentration and 88.6% purity. CONCLUSIONS: Due to this high Etx purity, the processes used in this study can provide the technical knowledge of toxin production in a larger industrial scale that can be used in development of clostridial toxoid vaccines, as well as quality control and/or diagnostic tests.

BACKGROUND: Nanoparticles are popular carriers for gene therapy and drug delivery. Their low toxicity effects, as well as their ability to accumulate and enter mammalian cells, illustrate their importance. OBJECTIVES: The aim of this experimental study was to investigate the effects of molybdenum trioxide nano-particles on liver structure and function. METHODS: Thirty-five adult Wistar rats were studied and placed in five groups. The control group took any drug, the solvent group received normal saline, and groups 3, 4, and 5 received 50, 100, and 200 mg/kgBW molybdenum trioxide nanoparticles (MoO3 NPs), respectively, by intraperitoneal injection for 35 days. In the end, serum levels of AST, ALT, ALP, T3, T4, TSH, and VLDL were investigated. Moreover, liver tissue was evaluated in terms of morphometrical, histological, histochemical, and image analysis. The Hematoxylin-Eosin, Masson's Trichrome, and Periodic Acid Schiff staining methods were utilized for liver tissue evaluation. RESULTS: The results showed that molybdenum trioxide nanoparticles significantly increased serum levels of the liver enzymes and thyroid hormones and decreased TSH in MoO3 NPs groups compared with control and solvent groups. Also, histomorphometric and histochemical evaluation and image analysis of liver tissue indicated adverse effects of MoO3 NPs on liver tissue. They showed that the accumulation of carbohydrates in hepatocytes was de-creased, and collagen fibers stained by Masson's Trichrome staining were increased in MoO3 NPs groups. CONCLUSIONS: It can be concluded that nanoparticles such as MoO3 NPs affect and damage the histological structure of the hepatocytes. Also, MoO3 NPs can alter serum levels of liver enzymes by affecting and damaging hepatocytes.

BACKGROUND: Developmental anatomy is a prerequisite for a real understanding of gross anatomy and teratol-ogy. It is concerned with the sequential stages of embryonic and fetal development, beginning with fertilization. Moreover, it helps to describe developmental changes and abnormalities, heredity, sexing, and the appearance of vestigial structures. Powerful advancements in molecular genetic manipulation and assisted reproductive technolo-gies are employed during embryo and fetal development, and these efforts have had profound impact on animal production worldwide. OBJECTIVES: The present study was carried out to investigate the onset and stages of osteogenesis in rabbit (Oryctolagus cuniculus). METHODS: Forty mature rabbits (33 does and 7 bucks) with a mean weight of 2 kg were included in this study. They mated twice at a ratio of three does to one buck on day zero (0). Mounting was carefully observed to ensure mating occurred and was confirmed by the physical examination of the vulva for swelling and redness, while preg-nancy diagnosis was confirmed by ultrasonography and abdominal palpation. Embryos and fetuses were extracted via a ventral incision on the abdominal and uterine walls of one pregnant doe each day after euthanization with thiopental sodium at the dose of 31 mg/kg body weight intravenously. Diaphonisation was employed in studying osteogenesis. RESULTS: Osteogenesis began at fetal day 21 (F21) using diaphonisation. In the skull, the bones of the splanchnocranium appeared before the neurocranium. The centrum and transverse processes were the first identifi-able features of all different types of bone in the vertebral column to be ossified. The spinous process and the fusion of the sacrum and sternum were not detected throughout the gestation period. It was also observed that the epiphys-eal and articular ends of none of the bones, neither in the fore nor hind limbs were ossified throughout gestation. Specifically, while the primary ossification centers of the middle phalanges were the last to appear in the manus and pes, all the carpals were absent, and only the calcaneous was evident in the tarsal bones. CONCLUSIONS: We recorded the onset of osteogenesis and subsequent development throughout the gestation period of rabbits, which has added some valuable information to the documented literature on the bone development of this species.

BACKGROUND: Avibacterium paragallinarum causes infectious coryza that is an important disease of chickens associated with an acute upper respiratory infection, growth retardation, marked drop in egg production, reduced hatchability, and increased number of culls. Infectious coryza has been reported from all around the world including Iran where chickens are raised. OBJECTIVES: This study was conducted to isolate Avibacterium paragallinarum from the suspected cases of infectious coryza in the backyard and commercial layer chickens in three provinces of Tehran, Alborz, and Qazvin in Iran, to characterize the isolates by molecular methods and to determine their antimicrobial susceptibility profile. METHODS: Swab samples from eye secretions and mouth cavity were provided from five commercial laying farms (25 samples) and backyard chickens (20 samples) suspected of infectious coryza in Tehran, Alborz, and Qazvin provinces of Iran. Standard bacteriological and biochemical procedures were performed for the isolation and identification of Av. paragallinarum. The antimicrobial susceptibility of the recovered isolates was determined by the agar disk diffusion method. HPG-2 PCR was used to confirm Av. paragallinarum using the specific primers of N1 and R1, resulting in a 500 bp amplicon. PCR-amplified hmtp210 gene with the amplicon size of 1.6 kb was subjected to sequencing with the standard Sanger sequencing method and phylogenetically analyzed. RESULTS: Three Av. paragallinarum isolates were obtained from all the cultured samples. Antimicrobial sensi-tivity test revealed that all three isolates were resistant to amoxicillin, oxytetracycline, streptomycin, ampicillin, and colistin while they were susceptible to cephalexin, ceftriaxone, florfenicol, gentamicin, linco-spectin, neomycin, and doxycycline. In phylogenetic analysis, two different genotypes of Av. paragallinarum were found. CONCLUSIONS: In this study, Av. paragallinarum isolates recovered from layer flocks were genotypically closely related to the strains from serovar C while the isolate recovered from backyard chickens was closely related to serovar B strains. Our results showed that the antimicrobial susceptibility is highly variable among the Av. para-gallinarum isolates compared to previous studies. Future studies are required to develop better immunogenic strategies and eventually novel vaccine candidates to control the disease and reduce the risk of infection with multi-drug resistant Av. paragallinarum isolates.