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: Infectious bronchitis is a highly contagious disease which may cause poor weight gain and low feed efficiency in infected chickens. There are a large number of reported serotypes/genotypes, which makes the control of the disease more difficult through vaccination. However, there are only a few amino acid differences in the S1 protein of vaccine and wild type strains which are responsible for protection. OBJECTIVES: The purpose of this study is to compare IBV variants isolated from commercial chicken flocks in Iran with currently used vaccine strains. METHODES: The partial S1 gene of the spike protein, covering a hypervariable and constant regions, was amplified and sequenced using conventional RT-PCR. RESULTS: Phylogenetic analysis of amino acid sequences revealed that eight of total nine isolates were divergence at least 21.8% from vaccinal Massachusetts serotypes, and six of nine isolates were divergence at least 22.7% from 4/91, and none of the nine isolates were similar to Dutch-type, D274,vaccine serotypes. CONCLUSIONS: These findings are essential for continuous surveillance disease control strategies and monitoring of variants, and thus emphasize on the importance of improving the vaccination program in Iran.

BACKGROUND: Zeolites containing silver ion, in combination with synthetic fibers, show antibacterial activity. OBJECTIVES: The purpose of this study was to use silver zeolite indirectly as antimicrobial agents to control Streptococcus iniae infection which recently has caused disease in some of rainbow trout farms in Iran. METHODES: In this context polyurethane foams containing silver zeolite (10 and 20%) were used in water filtration of semi circulation culture system of rainbow trout fry. After addition of Streptococcus iniae (105 Cell/ml) to water in culture systems, the filters were evaluated for efficacy in inhibiting bacteria through measuring bacterial loading in water, monitoring disease symptom and culture of bacteria from kidney and spleen. RESULTS: The results indicated that filters containing silver compounds could significantly reduce load of bacteria from the water to 102 (p<0.05) compared to the control. Filter with 10% silver zeolite had higher efficiency among others. CONCLUSIONS: According to the results of this study, it seems that silver zeolite in combination with polyurethane foams has the sufficient potential to control bacterial infection and disease prevention in semi circulation system of Rainbow trout. Development of these filters and their application in control of aquatic animal diseases can result in reduction of using chemical drugs.

BACKGROUND: Oxidative stress reflects an imbalance between the reactive oxygen species (ROS) and a biological system's ability to readily detoxify the oxidative agents. Disturbances in the normal redox state of cells can cause toxic effects through production of peroxides and free radicals that damage all components of the cell, including proteins, lipids, and DNA. ObjectiveS: The purpose of this study was to evaluate the oxidative status in calves within 3 days of birth. Methods: Twenty calves from Zagros dairy farm were selected. Blood samples were collected from the jugular vein at 0 (before administration of colostrum), 24, 48 and 72 hours after birth for measurement of serum levels of TBARS, Superoxide dismutase and catalase. Results: The results indicated higher levels of serum malondialdehyde concentration at birth that subsequently decreased at 24 and 48 hours after birth (p<0.05). There were lower levels of serum concentration of catalase at birth that followed by increasing in it at 24 and 48 hours after birth (p<0.05). Also, the concentration of superoxide dismutase was lower at the birth that subsequently increased at 24 hours after birth (p<0.05). Conclusions: Based on this study, it seems that antioxidant capacity of calves has been increased within 3 days of birth. Improvement of oxidative status in calves could be due to gradual increasing of their antioxidative capacity and also beneficial effects of colostrum.

BACKGROUND: Considering differences in head size and shape of different Equine breeds, biometric parameters can be an attribute to a particular race. OBJECTIVES: The purpose of the present paper is to give a numerical definition of morphological characteristics of head region of the Darehshori horse. METHODS: Twenty mature Darehshori horses were studied biometrically. The ear length, ears distance, eyes distance, head length, lateral head length, head width, rostrum length, distance between two mandibles and lateral face length were measured and the averages were calculated. RESULTS: The average of the related characters were as follow; ear length 16.89, ears distance 12.12, eyes distance 15.79, head length 55.26, lateral head length 49.33, head width 20.42, rostrum length 23.68, distance between two mandibles 10.82 and lateral face length 39.88 centimeter. CONLUSIONS: The coefficient of variation of these characters showed that the head length, lateral face length and lateral head length are more reliable characters than the other indices in characterizing the Darehshori horse.

BACKGROUND: Major histocompatibility complex (MHC) in chicken has profound influence on resistance/susceptibility to disease, and production and reproduction traits. Microsatellite marker LEI0258 is a genetic indicator for MHC haplotypes. Recognizing diversity of MHC haplotypes in selectively bred populations will be helpful for selecting population resistant to disease and development of effective vaccines. Objectives: The purpose of the present study was to evaluate polymorphism at MHC in two populations of Khorasan indigenous chickens and commercial Leghorn breed using microsatellite marker LEI0258 and to investigate its segregation and heredity. Methods: A total of 335 blood samples from Khorasan Razavi indigenous chickens and commercial Leghorn population including parents (P) and offspring (F1), were analyzed. The MHC genotypes were determined using LEI0258 microsatellite. The study of allele heredity from P to F1 and Hardy-Weinberg equilibrium were conducted using Chi-square and Likelihood Ratio tests. Results: In Khorasan indigenous chickens 20 different alleles were identified for LEI0258 microsatellite. The allele 321 bp had the highest (22.88%) and the allele 182 bp had the lowest (0.16%) frequency. In the commercial population (Leghorn breed) 3 alleles were found for this marker of which the allele 261 bp had the highest (50%) and alleles 487 bp had the lowest (6 %) frequency. In allele heredity analysis and Hardy-Weinberg equilibrium of Khorasan population, no significant differences were observed between P and F1 progenies. ConclusionS: These results indicate a higher genetic variation in indigenous chickens compared to commercial breed. There was no preference for a particular allele in indigenous chickens. The higher frequency of some alleles in F1 population is due to the high frequency of the same alleles in parent population which their gametes make the population gene pool.

BACKGROUND: Vibrio paraheamoloyticus is one the causative agents of vibriosis with high mortality in farmed fish and shrimp and under predisposing conditions.                                  OBJECTIVES: This study was aimed to assess the effect of gamma irradiation on the inactivation of V.  paraheamoloyticus under fresh and freeze-dried conditions. METHODS: Vials of 0.5 ml fresh culture of the bacterial suspensions at  1.5*1010 cfu/ml were subjected to 1, 1.5,2, 2.5, 3 and 4 KGy. Also, vials of 0.5 ml freeze-dried culture of the bacterial suspensions at  1.5 x 1010 cfu/ml were subjected to 2, 4, 7 and 8 KGy. The bacterial growth behavior was then evaluated on fresh medium. RESULTS: The obtained results showed that the minimum doses of 4 and 10 KGy were sufficient for the inactivation of fresh and freeze-dried bacteria, respectively. CONCLUSIONS: The result of this study shows that inactivation of V. paraheamolyicus in fresh culture condition requires below half- dosage of gamma ray required for  the inactivation of the freeze- dried of bacterial cells.

BACKGROUND: Major histocompatibility complex (MHC) plays a central role in regulation and control of the immune responses to infectious diseases. Due to its polymorphism, individual differences in response to vaccines have been observed in different chicken populations. Studying the association of chicken MHC with immune response to vaccines will help the control of infectious disease and vaccination success. Objectives: The present study aimed to evaluate the MHC polymorphism and its association with antibody response against infectious bursal disease (Gumboro), Newcastle (ND) and Influenza (AI) vaccines in Khorasan native chickens. Methods: Diversity of LEI0258 microsatellite marker (MHC genotyping) was investigated by fragment analysis method. Antibody titer against IBD was measured by ELISA and antibody titers against ND and AI vaccines were measured by Haemaglutination Inhibition (HI) assay. Statistical analysis was performed using SPSS software (version 21). Univariate regression analysis was performed using weighted least squares with weight number of progeny mean data. Results: Total of 13 LEI0258 microsatellite alleles were identified in Khorasan native chickens which indicated a high genetic diversity in the population. The allele 361 bp had the highest (28.48%) and the allele 350 bp had the lowest (0.69%) frequency, respectively. In evaluating the association of MHC with immune responses, 311 and 313 bp alleles were significantly associated with elevated immune responses to Newcastle vaccine, while allele 266 bp was associated with lower IBDV antibody titers (p<0.05). ConclusionS: According to the important role of MHC in controlling infectious disease resistance or susceptibility and quality of immune responses, these results could be used for selection and improving the populations under selective breeding.

BACKGROUND: Cryptosporidium parvum is a protozoan parasite which belongs to apicomplexa phylum. The parasite infects both wild and domesticated animals and human beings as well. OBJECTIVES: The purpose of the present study was to detect oocyst shedding and diarrhea pattern in experimental cryptosporidiosis and their correlation with weight loss in neonatal calves. METHODS: Twelve Holstein calves of both sexes were obtained at birth from dairy farm and randomly divided into two groups of 6 calves. Six calves were orally infected with 107 C.Parvum oocysts at the 12h post parturition. The control group was not infected. Clinical signs were examined and fecal samples were collected by the rectal examination twice a day. All calves were weighed from day 0 to day 30 with 3 days intervals to determine effects of cryptosporidiosis on weight gain. RESULTS: All infected calves were noticeably depressed and had a decreased appetite from 3 days post inoculation (DPI) while they received colostrum. Subsequently, watery diarrhea with clumps of mucus and yellow or pale changes of feces color were observed. The infected calves have had diarrhea for 5-8 days that remarkably had got dehydrated. The most severity of diarrhea was 4-6 DPI. Oocyst excretion started 4 DPI, peaked at 6 DPI (60.48×106±9.03oocysts/g feces) and continued until 11 DPI. Control calves had no diarrhea and other clinical signs during the whole period of the trial. The mean weight gain of control group was significantly higher than inoculated group during experiment (p<0.001). The Weight of the infected calves was retarded until 9 days old and then risen subsequently. CONCLUSIONS: Present study showed the role of C.Parvum as the primary cause of diarrhea and weight loss among neonatal calves.

BACKGROUND: Theileriosis is a blood protozoan disease with high mortality in cattle in tropical and subtropical regions of the world. Several studies were conducted to identify Theileria species in infected cattles and vector ticks by microscopic examination. However, microscopic technique has lower sensitivity compared to molecular method.                  OBJECTIVES: This study was carried out to identify Theileria species and its carriers in cattles of Yazd city, sing semi nested PCR. METHODS: Between June to September of 2012, 100 EDTA blood samples and 249 ticks were collected from Holstein breed with no history of vaccination against the ileriosis in Yazd area. The collected samples were transported to the laboratory, then prepared the blood smears and stained with Giemsa method. Also, the collected ticks were separated into 50 tick pools, according to their species. Then their salivary glands were removed using stereomicroscope in 0.85% saline. DNA of blood and salivary glands was extracted using a commercial kit and analyzed by Semi-nested PCR. PCR-RFLP was also used to differentiate Theileria lestoquardi from Theileria annulata in positive samples of ticks. RESULTS: Ring forms of Theileria spp. were found in 4 (4%) of blood smears. All ticks were Hyalomma a.anatolicum. Results of PCR were indicated that 11 (11%) of blood samples and three pools of tick’s salivary glands were infected with Theileria. Theileria annulata were only detected in all positive samples by Semi-nested PCR. The results of PCR-RFLP using MspI enzyme showed that the tick’s salivary glands were negative to Theileria lestoquardi infection. CONCLUSIONS: Based on the results, it is concluded that Theileria annulata and Hyalomma a.anatolicum are important agent and vector tick of tropical theileriosis in dairy cattles of Yazd area.