مجله طب دامی ایران
سال:1393 | دوره:8 | شماره:2 |تعداد مقالات:15

BACKGROUND: Newcastle disease virus (NDV) is the causative agent of the Newcastle disease (ND), a highly contagious disease in birds that causes significant economic losses to the poultry industry worldwide. ND is endemic in Iran and outbreaks are reported regularly in commercial poultry flocks and different species of birds.OBJECTIVES: The current study was carried out to characterize NDV based on phosphorprotein (P) gene from recent outbreaks in Iran, 2010-2012.METHODS: The P gene fragment of NDV isolates of five chickens, 1 ostrich, and 1 Pigeon paramyxovirus-1 was obtained by RT-PCR and sequenced.RESULTS: Phylogenetic analysis of sequences revealed that chicken and ostrich NDV isolates were closely related and placed in the genotype VII and Pigeon Paramyxovirus-1 was located in the genotype V.CONCLUSIONS: This is the first report of Phosphoprotein gene sequences of NDV strains isolated in Iran. This study will help us to understand the epidemiology and molecular characteristics of Newcastle disease virus in Iran.

BACKGROUND: Tetracyclines (TCs) are broad-spectrum antibiotics that are widely used in veterinary medicine. The presence of TCs residues in milk is a public health concern all over the world.OBJECTIVES: This study aimed to determine TCs residuals in pasteurized milk marketed by some dairy companies in Tehran from April 2011 to March 2012.METHODS: 432 pasteurized milk samples were purchased from supermarkets supplying the milk products of 12 major dairy companies in Tehran (3 samples from each company every month), and they were stored at -20 oC until analysis. Oxytetracycline (OTC) and Tetracycline (TC) residues in each sample were extracted by a liquid - liquid phase procedure and quantitated using a high performance liquid chromatographic (HPLC) method. Chromatographic conditions included a mobile phase as oxalic acid buffer- acetonitril (80: 20) with a flow rate of 1mL/min and UVdetection at 355 nm.RESULTS: TCs residuals in most milk samples were lower than 100 ppb, maximum residue level (MRL); however, in seven samples (1.62%) the total residues of OTC and TC were more than MRL. In the latter milk samples, the median total TCs residue was 625 ppb, ranging between 274 and 1270 ppb.CONCLUSIONS: Because of the presence of TC residues above the MRL level in a limited number of milk samples, it is concluded that more studies and supervision of health authorities are needed in this field.

BACKGROUND: Occurrence of resistance against antibiotics and inadequate efficacy of some vaccines necessitates studies of natural immunostimulators in aquaculture. Shrimps shell derived from Chitosan can be used as immune stimulators in fish.OBJECTIVES: In this study, the effects of oral administration of chitosan, derived from shrimp shell, on some immune responses and disease resistance in Cyprinus carpio were studied. METHODS: Three hundred healthy fish weighing 42.4+8.1 g were divided into 4 equal groups: the first group (G10) was fed with food supplemented with 10 mg kg-1 chitosan, the second (G5) and third groups (G2.5) were fed with food supplemented with 5 mg kg-1 and 2.5 mg kg-1, respectively. The control group was fed with basal feed (without chitosan). All groups were treated for 60 days. Blood samples were taken on 0, 20, 40, and 60 days post- experiment; In addition, some immunological indices, including serum lysozyme activity, serum bactericidal activity, Nitro Blue Tetrazolium (NBT) reduction activity, serum proteins, white blood cell count (WBC), and differentiated count were measured. At the end of the treatment, fish were challenged with live Aeromonas hydrophila and mortality rate was recorded for 14 days.RESULTS: Oral administration of chitosan (0.5 and 1%) significantly enhanced NBT reduction activity and resistance to A. hydrophila infection (p=0.012). Serum lysozyme and bactericidal activity, serum total protein and globulin, WBC and leukocytes ratio showed no significant change among the groups (p>0.05).CONCLUSIONS: This study indicates that oral administration of shrimp shell chitosan may have a positive effect on some immune parameters and resistance against bacterial infection in Cyprinus carpio.

BACKGROUND: Aflatoxin B1 (AFB1) is a toxic metabolite produced by Aspergillus species that contaminates a wide range of agricultural products.OBJECTIVES: This study was designed to develop a rapid and highly sensitive immunoassay method in microarray format for quantitative detection of AFB1 to evaluate the potential of microarray platform for high-throughput screening, which can be beneficial in food and feed industry.METHODS: Following successful optimization, using an indirect competitive immunoassay in dot blot format, AFB1-bovine serum albumin (AFB1-BSA) conjugate was contact-printed onto 16 isolated subarrays on multi-pad nitrocellulose coated slides; subsequently used in competitive binding assays.RESULTS: Using the aforementioned assay, AFB1 was determined from 15 pg/g to 3.04 ng/g working range with detection limit (LOD) of 1 pg/g. To evaluate assay performance in real food matrices, the authors spiked wheat samples with different concentration of AFB1. After extraction, working ranges of 0.11-4.15 ng/g with detection limit of 30pg/g was determined. Good recoveries (94±9%) were obtained, demonstrating accurate detection of AFB1 concentrations in wheat samples. Assay procedure completed in 3 hours.CONCLUSIONS: The results indicated that the proposed developed assay in microarray format could be used for rapid and sensitive detection of AFB1in wheat samples.

Perosomus elumbis is an occasional congenital anomaly of cattle, swine, sheep, and dogs with unknown etiology. This congenital abnormality occurs in both sexes. A dead Holstein calf characterized by musculoskeletal and external genitalia abnormalities was referred to the large animal hospital of University of Tehran. Radiographic evaluation and subsequent dissection revealed that the vertebral column was truncated at the level of first lumbar vertebra (L1). Moreover, L2-L5, sacrum and coccygeal vertebrae were absent. The dorsum of the lumbosacral region contained only soft tissues. Urogenital tract was incomplete, and it contained agenesis of the ovaries, uterine tubes, cervix, and vulva concurrent with unilateral umbilical artery agenesis. Small and large intestine contained blind-ended sacs. No testes, scrotum, and penis were found. The intact ureter was attached to a thin-walled fluid fill sac. The laboratory finding showed that the pH of the fluid was 6 and contained hemoglobin, white blood cells, bacteria, a few red blood cells, oxalate crystalline, and epithelial cells. It was concluded that the collected fluid was urine. This is the first report of perosomus elumbis in a Holstein calf having a lot of visceral abnormalities in Iran.