مجله میکروب شناسی مواد غذایی
سال چهارم شماره 12 (تابستان 1391)

Benzo [a] pyrene is one of the most common and potently carcinogenic polycyclic aromatic hydrocarbons (PAHs). The aim of this study was to investigate the effects of B[a]P on the histological status of the kidney in the Epinephelus coioides. In this study, we investigated the histopathological alterations in the kidney of the E. coioides after exposure to B[a]P. 100 immature protogynous E. Coioides were exposed to different concentrations of BaP (0, 2, 20, 200 mg/kg) for 14 days after one week acclimation period. Six fish were randomly selected from each treatment in 4, 7 and 14 days of experiment. After necropsy, their kidneys were fixed in Bouin‘s solution for 2 weeks. Sections in six-micrometer thickness were obtained and stained with Hematoxylin-Eosin for examination by light microscopy. On the basis of the results, melanomacrophage centers, glomerular capillary dilation, thinking of glomerular basement membrane (GBM) and necrosis were the most common pathological changes in all treatments in all days. The degree of severity and extension of alterations was more in higher doses.

Piroplasmosis in equids is a hemoprotozoan tickborne disease with worldwide distribution caused by Theileria equi and Babesia caballi. The aim of this study was to investigate T. equi and B. caballi infections in equids in North Khorasan Province. Blood samples were collected from 206 equids including 100 Turkoman breed horses (Equus caballus) and 106 donkeys (Equus asinus) in 20 villages. Blood smears were prepared and stained with Geimsa method. T. equi was microscopically detected in nine blood smears including 5 (5%) horses and 4 (3.7%) donkeys. B. caballi was not observed. Any siginificant difference was not observed between the piroplasm infection and activity. It was concluded that T.equi infection is endemic in Turkoman breed horses and donkeys in North Khorasan province, Iran.

The common liver termatod, Fasciola gigantica, infects a wide range of vertebrate hosts, and is found frequently in domestic ruminants such as cattle, sheep and goats. Diagnosis of F. gigantica infection is usually based on fecal egg counts or serological assays of which some are based on antigen detection in serum. Antigen detection provided early diagnosis of infection. The protein 14-3-3 of F. gigantica is an important diagnosis antigen for using in diagnostic tests and vaccine related researches. The aim of this study was the cloning of 14-3-3 gene of F.gigantica in pMal-c2x, a prokaryotic expression vector, and its expression in TG1 strain of E. coli. For this purpose, nucleotide sequence of the 14-3-3 encoding region of F. gigantica genome was obtained from the Gene bank and analyzed to design a primer pair for RT-PCR amplification of the gene. The 14-3-3 gene was subsequently amplified by RT-PCR. The vector and 14-3-3 gene both were digested by BamH I and HinIII, Sal1 and EcoR1 restriction endonucleases and ligated by T4 ligase. The construct was then used for transforming E. coli TG1 strain and the protein expression was confirmed by SDS-PAGE. The result showed that this recombinant plasmid effectively express 14-3-3 gene.

Cellulolytic anaerobic fungi are found in digestive tract of sheep, cow, and goat and in the most of ruminant and non-ruminant animals. The zoospores of these fungi attach to plant fibers and produce a wide range of polysaccharide degrading enzymes such as cellulase. In the present study the rumen samples obtained from sheep from Isfahan abattoir and the fungi isolated in anaerobic condition with Orpin specific medium and identified using mycological keys. The medium saturated with CO2 for anaerobic conditions achievement. The isolated fungus identified as Caecomyces genus according to macroscopic (colony morphology) and microscopic (zoospore type, sporangium and rhizoid shape) characteristics. For the cellulolytic activity, every microgram of released reduced sugar in a minute defined as one unit of enzyme activity on the substrate. The cellulolytic enzyme activity on three types of substrates, carboxymethyl cellulose for endoglucanase, avicel for exoglucanase and cellobiose for beta-glucosidase were daily evaluated. Also, the enzyme activity on different pH values and substrate concentrations assayed for activity optimization. The isolated fungus, with monoflagelated zoospore and oval sporangium defined as Caecomyces genus. The best enzymatic activity on the different concentrations of three substrate types found in the third day. The concentrations was 0.1 g.ml-1 for carboxy methyl cellulose (9.624 U min-1 enzyme activity); 0.03 g ml-1 for avicel (10.771U min-1 enzyme activity) and 0.03 g ml-1 for cellobiose (38.530 U min-1 enzyme activity). The optimum pH value of 6 obtained for the activity of enzymes. The anaerobic fungus, Caecomyces had the best enzyme activity on non crystal substrate, cellobiose.

An experiment was carried out to study the effect of different levels of L-threonine supplementation on some blood parameters of broilers in 9- to 49-day-period. 270 day old chicks consisted were distributed randomly assigned to nine dietary treatments. Each treatment composed of three floor-littering replicates of 10 birds. Experimental diets contained three levels of protein (21, 19.5 and 18 %) and three levels of threonine (NRC, 0.06, 0.07 %), respectively. The results showed that the change in the level of protein did not have any significant effect on blood urea concentration and blood glucose. Reduce excessive protein, leading to a significant reduction in blood triglyceride and cholesterol concentration (P<0.05). The chenge level of thereonine on blood urea concentration and cholesterol the effect was not significant. With threonine supplementation resulted in a significant reduce in glucose and triglyceride concentrations (P<0.05). Reduce excessive protein, leading to a significant reduction in blood hetrofile perecent (P<0.05) though on blood lymphocyte perecent and proportion hetrofile to lymphocyte the effect was not significant. The chenge level of thereonine on blood hetrofile perecent, lymphocyte and proportion hetrofile to lymphocyte the effect was not significant.

This study was carried out to determine the prevalence of subclinical ketosis and relation to periparturient disorders in dairy farm in Shahr-e-kord. A total of 20 multiparous Holstein cows (parity 2-9) were randomly selected from 5 commercial dairy herds. Since the likely risk time for occurrence of ketosis is during 2-5 weeks after parturition, the blood samples were taken wk 1 before calving and at wk 2 and 3 after calving. From 3 weeks before calving to 3 months after calving, peripartum diseases informations including milk fever, metritis, mastitis, clinical ketosis, displaced abomasum, retained placenta, dystocia, pneumonia and lameness were gathered in data sheet form. Beta-hydroxy butyrate was measured in serum by using automated analyzer and statistical analysis was performed to investigate the prevalence of ketosis (clinical and subclinical) and related periparturient diseases. The prevalence of subclinical ketosis, using cut-off 1200 μmol/lit of beta-hydroxy butyrate was 0.98 in wk 1 before, 9.8 in wk 2 and 13.79 percent in wk 3 after parturition respectively. It was shown that there is a significant correlation between subclinical ketosis and left displacement of abomasum, metritis and mastitis, separatively so that the odds ratio of each disease was 9.74, 4.26 and 6.64 respectively.

The aim of this study was to evaluate the biochemical changes in optic lens in selenite- induced cataract and the preventive effect of vitamine E in Sprague-dawly rats. Three groups of rat were selected. Control group (10 rats) did not receive any injection, test group (16 rats) were received a single injection of sodium selenite (13 mg/kgBW) at day 10 post-partum and treatment group (15 rats) received vitamin E a rat pups were received selenite injection like test group and subcutaneous injection of vitamin E (60 mg/kg BW) in two days interval from day 8 postpartum up to end of study. Slit-lamp biomicroscopic examination was performed on each eye of each rat pup in the day 14 and 28 after selenite injection. Rats in each group were euthanized in at day 14 and 28 after selenite injection. Lenses of rats were removed and analyzed for protein content. In test group 95% of rats developed mature cataract and protein content of lens extract (3.9 mg/kg) was significantly lower than control group (4.5 mg/kg) (p>0.05). In treatment group 80% of ratsdeveloped cataract. Free and total SH content decreased significantly from 42 and 45 µmol/ ml lens extract in control group to 36.5 and 39.2 µmol/ ml lens extract in test group (p>0.05). Vitamin E restored this value to 37.2 and 40.6 µmol/ ml lens extract. The results obtained that vitamin E is effective in preventing selenite-induced catarct in animal model and indicated interference in sulfhydryl-disulfied exchange in cataract.

In the first phase of study, 6 cross bred bulls (HF) between 4-6 years of age selected and feed with subabul and feed residues. Their urine and blood samples were collected daily for 7 days continuously after morning and evening feeding, then were sent for hemoglobin and blood platelet volume estimation. In the second phase of study 12 cross bred cows (HF) with the average milk yields 10 lit / day randomly divided to two subgroups as treatment groups, each sub group included 6 cross bred cows. The first sub group as treatment group animals feed with subabul and Napier hybrid with 50:50 proportion with grinded maize crop, and the second subgroup as control group animals feed with feed straws of (mixed sun flower, cotton seed and soy bean and concentration. The cows in the both phases have been kept under intensive condition with the proper care and managed with the approved feeding planning. Milk sampling were conducted for estimation of nitrogen and lipid twice/day for three weeks and the collected data were subjected to statistical analysis at the level of (P Keywords: Feedingvalue, Subabul, Economicalexpect, Feed cost