BACKGROUND: Lactococcus lactis is one of the lactic acid bacteria that can be considered as a probiotic in Persian sturgeon. OBJECTIVES: The aim of the present study was to increase the resistance to Aeromonas hydrophila after feeding the L. lactis JF831150. METHODS: In the present study, first 60 fish were fed different doses of L.lactis JF831150 for 56 days. The bacterial flora were counted with  TSA and MRS. Resistance of fish against A. hydrophila were considered after feeding. RESULTS: The use of L. lactis JF831150 for 56 days in P. sturgeon showed significant improvement in decreasing heterotrophic aerobic bacteria flora and increasing the lactic acid bacteria in the intestine. In the face of fish against A. hydrophila in third treatment (108 CFU/g), the survival rate was shown to be significantly higher than the control and other treatments. CONCLUSIONS: The results showed that consumption of L. lactis JF831150 (108 CFU/g) could improve the intestinal flora and increase resistance to A. hydrophila, and therefore has  potential for use  with P. sturgeon.

BACKGROUND: Strangles is caused by Streptococcus equi subspecies equi. The bacteria typically infect the upper respiratory system and lymph nodes of the head and neck in equidae. OBJECTIVES: The aim of this study was to evaluate the prevalence of strangles and association of this infection with host age and geographical determinants in horses in Khuzestan province. METHODS: Serum samples from 184 horses were randomly collected in Ahvaz, Shoushtar, Baghmalek, Shoush, Abadan, Ramhormoz and Dezfool cities and were examined by ELISA assay. Also, 85 swab samples were randomly taken from nasal swab of horse and evaluated for Streptococcus equi subspecies equi by bacterial culture. RESULTS: Seroprevalence rate of strangle was 37.5% (95% CI: 30.5-44.5%). Logistic regression showed that the odds of infection between the age based on year and disease was 1.1 (95% CI: 1.04-1.17) (p<0.001), and with increase of 1 year-old, odds of infection increase 10%. Relative frequency of infection in male and female horses was 32.73 and 39.53%, respectively (p>0.05) and odds of infection in female compared with male horses was 1.34 (95% CI: 0.69-2.61). Prevalence rate in horses with and without history of respiratory disease was 94.1% and 31.74%, respectively (p<0.001). The odds of infection in horses with history of respiratory disease compared with  healthy horses was 34.42 (95%CI: 4.45-266.37). Prevalence rate in  Ahvaz, Shoushtar, Baghmalek, Shoush, Abadan, Ramhormoz and Dezfool  was 33.3%, 34.62%, 5.26%, 69.23%, 13.04, 22.22% and 75%,  respectively (p<0.001). Geographical location explained 29.6% of infection’s fluctuations. No isolate of Streptococcus equi subsp. equi was obtained in culture of nasal swab samples. CONCLUSIONS: This study determined that seroprevalence of strangles should be deleted in khuzestan province is high and Prevention and control measurements should be considered by health authorities.

BACKGROUND: Recent investigations  have identified anthelminitic effects of many medicinal plants particularly from condensed tannin sources. In addition, gastrointestinal nematodes of ruminants have a negative effect on the farming industry worldwide. Objectives: The aim of the present study was  to determine the potential anthelmintic effects of Quercus robur extract on alimentary canal nematodes in naturally infected sheep by faecal egg count reduction test (EPGRT). Methods: The crude aqueous extract was prepared from Quercus robur as tannin extract. The nature and intensity of helminth infection was determined by coprological examination. The faecal samples of 600 sheep were collected from different regions of Kurdistan province. The samples were examined by flotation method (Clyton-Lane technique). Fifteen sheep with the most count in egg per gram (include Marshallagia, Nematodirus and Trichostrongylids) were divided into three groups of five animals: First group (test group) were drenched with Quercus robur extract at 3.75g/kg, second group (positive control group) received Albendazole 2.5%, orally at 5mg/kg and third group (negative control) without treatment. Results: The results of faecal examination  3 days after administration indicated significant reduction of EPG in both group’s treatment and positive control groups, 90.76% and 90.83% respectively, whereas there was no effect in the third group. Results were evaluated by Chi-square analysis and showed significant differences between treatment and negative control groups (p≤0.05). Nosignificant differences were observed between treatment group and positive control group (p≥0.05). Conclusions: Results reveal that aquatic extract of Quercus robur has anthelminitic activity and further large scale studies are suggested to confirm pharmacologic effects of this herbal extract.

BACKGROUND: Clostridium difficile (C. difficile) infection is one of the most important diseases in healthcare facilities and community. Ribotypes 027 and 078 are known as hyper-virulent strain of C. difficile in molecular study. PCR-ribotyping is a suitable method to interpret the relation of C. difficile isolated from food and hospital. Objectives: In the present study, the clostridim difficile binary toxin (cdtB) and ribotype pattern evaluated in toxigenic C. difficle isolated from beef. Methods: Detection of cdtB in 12 toxigenic C. difficile (encoding tcdA and tcdB gene) isolated from 100 beef samples was determined through PCR. Afterwards, PCR-ribotyping was performed to examine the ribotype patterns of C. difficile. Results: cdtB gene was not detected in any positive isolate. Ten different patterns were observed in 12 toxigenic isolates. No similarity existed in the ribotypes of our study with ribotypes 027 and 078. Conclusions: Albeit  ribotyp 027 and 078 were not found in our study, the isolation of toxigenic C. difficile with new ribotypes in Iran may indicate the probable hazard of this bacterium in public health. Comprehensive research about C. difficile in different food sources is recommended on a national level.

BACKGROUND: The term ‘‘marinated fish’’ is used to define semi-preserved fish made by immersion in a solution of organic acids or vinegar and salt. Objectives: This study was conducted to compare  nutritional value (Lipid, Protein, Moisture, Ash, pH), chemical (TVB-N, PV, TBA, FFA) and sensory attributes, microbial communities (TC, Mold) and fatty acids profile of cooked and fried marinades and 30 days storage at 4°C. Methods: The marinades were produced using formulas from Silver carp fresh fillets. Then the products were stored at 4°C and sampling was done to determine of quality indexes during storage, every 10 days. Results: The results showed that there were no differences in moisture, protein and lipid contents between two products (p>0.05). Also, there were no differences with regard to  PV, TBA and FFA between two marinades (p>0.05), but TVB-N in cooked and fried products (with 16.46 and 18.91 mg/100g) showed significant  changes (p<0.05). In addition, total  bacteria count was 4.19 and 4.89 and total mold-yeast was 2.47 and 2.60 Logcfu/g at day 30 in cooked and fried marinades, respectively (p<0.05). As sensory aspect, appearance, color, texture and odour attributes showed  better points in fried marinade,  cooked product had more acceptable  taste (p<0.05). However, there was no difference in overall acceptance. Omega-3, omega-6 and EPA+DHA fatty acids had higher amounts in fried marinade (p<0.05). Cooking reduced the UFA amount, but conversely, frying increased it. Conclusions: Quality of both marinades was acceptable during 30 days storage refrigerator, but fried marinade showed a preferred quality as sensory attribute.

BACKGROUND: Lead (Pb) induced oxidative stress is known to suppress growth performance in broiler chickens. The current study was carried out in an attempt to describe the specific underlying mechanisms of such phenomenon. OBJECTIVES: The objective of this study was to investigate the effect of Pb-induced oxidative stress on performance, antioxidant status and behavioral responses of broiler chicken. METHODS: Eighty day-old broiler chicks were randomly assigned to 2 dietary treatment groups of 4 pen replicates, namely i) basal diet containing no lead supplement (control) and ii) basal diet containing 200 mg Pb/kg of diet. RESULTS: The results showed that addition of lead decreased body weight gain (p<0.01) and feed conversion ratio (p<0.01). Also, consumption of contaminated diet significantly increased MDA and H/L Ratio and significantly decreased SOD and GPx activity (p<0.01). Moreover, addition of 200 mg/kg diet significantly increased sitting pasture and aggression behavior and decreased feeding behavior (p<0.01).               CONCLUSIONS: Our data conclude that Pb-induced oxidative stress adversely suppressed feed conversion ratio and growth performance. The proposed underlying mechanism for such phenomenon is Pb-induced oxidative stress by impaired antioxidant status and feeding behavior decreased the growth performance.

BACKGROUND: Diazinon is an organophosphate pesticide which is widely used in paddy fields located in northern parts of Iran, though it is prohibited to be used in many countries. OBJECTIVES: The purpose of the present study was to investigate sublethal effects of diazinon on blood parameters of common bream Abramis brama. METHODS: In sublethal toxicity test, fish were exposed to diazinon concentrations of 0.04, 0.36, 0.73 and 1.46 mg/l for 14 days and their hematological parameters including WBCs, white cell differential count, RBCs, Hct, Hb, MCV, MCH and MCHC were studied.  RESULTS: The results of sublethal toxicity indicated that by increase of toxicant concentration a significant decrease was appeared in WBCs, RBCs, Hct, Hb and MCH both after 7 and 14 days (p<0.05). After 7 days a significant decrease was observed in lymphocytes count which accounted for about %81 of the control group. The neutrophils count was also face the same reduction so that after 14 days of diazinon exposure, the neutrophils counted decreased to about %85 of control group. CONCLUSIONS: Regarding the toxicity of diazinon on various hematological parameters and the diazinon concentration in Iranian waters and considering the fish habitat in the waters which are connected to the Caspian Sea it suggests that the pesticide diazinon affect the fish survival.

BACKGROUND: Increase of people’s awareness about side effects of chemical food preservatives has raised public interest to consume products with natural preservatives such as essential oils. Garlic (Allium Sativum L.) is one of the medicinal plants in traditional medicine of Iran and it is necessary to evaluate its antimicrobial effects on some food borne bacteria such as E.coli O157:H7. This bacteria has low infectious dose and causes hemorrhagic colitis and hemolytic-uremic syndrome. OBJECTIVES: The purpose of this study is to evaluate inhibitory effect of garlic essential oil (Allium Sativum L.) on growth of E. coli O157:H7 and shiga-toxin 2 (Stx2) production. METHODS: The minimum inhibitory concentration (MIC) of garlic essential oil was evaluated by broth microdilution method and minimum bactericidal concentration (MBC) methods. Effect of subinhibitory concentrations (subMICs) of garlic essential oil on bacterial  growth over 72 h (at 35 °C) evaluated by surface plate counting and production of Stx2 were evaluated by kit (VTEC-RPLA). RESULTS: MIC and MBC of garlic essential oil were estimated 0/02% and 0/04%, respectively. Concentrations of 0.005%, 0/01% and 0.015% of garlic essential oil reduced the bacterial growth. Concentration 0/015% after 72 h reduced 2 log10 (cfu/ml) growth rate and was the most effective concentration. Concentration 0/005% reduced Stx2 production and higher concentrations inhibited Stx2 production. It was found that the effect of different concentrations of essential oil on growth and production of Stx2 by E. coli O157:H7 were statistically significant (p≤0.05). CONCLUSIONS: Garlic essential oil showed to be effective against bacterial growth and production of Stx2. This study indicated that garlic essential oil can be used as natural preservative in food system.

BACKGROUND: Yersinia ruckeri is the etiological agent of enteric red mouth (ERM) or yersinioisis disease, one of the important bacterial diseases in the cultured salmonids. OBJECTIVES: The purpose of present study was detection of gyrA gene (quinolone resistance) in the Y. ruckeri bacterium. METHODS: In this study fish were evaluated in average size 8-12 cm from six rainbow trout farms in Chahar Mahal va Bakhtiyari province (Iran). In each farm 10 fish (totally 60) suspected to yersinioisis were randomly selected; sampling was done from lower part of intestine and cultured on Trpticase Soy Agar (TSA). The mediums were transferred to incubator and kept at 22 °C for 48 hours. Pure colonies which are grown on the mediums were tested by catalase, oxidase and gram staining, then those of gram-negative, catalase positive and  oxidase negative were diagnosed, and cultured on Waltman- Shots medium (as specific medium for Y. ruckeri). These mediums were incubated at 22 °C for 48 h. Colonies that were grown were tested by PCR method for Y.ruckeri detection. Then, in the identified strains of Y.ruckeri gyrA gene were detected by PCR test. RESULTS: The results of bacteriological, biochemical and molecular tests showed that three cases out of total isolates were identified as Y. ruckeri. In all isolates of Y. ruckeri, gyrA gene was identified by molecular test. CONCLUSIONS: Identification of quinolone resistance gene in Y. ruckeri isolates can be the reason of low efficacy of these classes of antibiotics in the aquaculture. ِTherefore, the policy of treatment should be changed specially in enteric red mouth disease.

BACKGROUND: Vitamins are considered an essential part in diet of aquatic animals. OBJECTIVES: This study was carried out to assay the effect of different levels of vitamin E on growth performance, carcass compositions and blood parameters of common carp fingerlings (Cyprinus carpio). METHODS: Total number of 96 common carp fingerlings weighing 15.49 ± 3.64 g were randomly distributed into 12 fiberglass tanks in four treatments group including control (without added vitamin), 100, 200 and 400 mg/kg vitamin E in three replicates and kept at a density of 8 fish per tank for 10 weeks. RESULTS: Results showed that the highest weight gain, percentage of body weight increase, mean daily growth, specific growth rate, condition factor and the lowest food conversation ratio were observed in fish fed with 200mg/kg vitamin E but no significant differences were seen compared to other treatments (p>0.05). Fish fed with 200mg/kg vitamin E had the highest (p>0.05) contents of protein and ash compared to control group. There was an increase in values of RBC, Hct and Hb in fish fed with 100, 200 and 400 mg/kg vitamin E in comparison with control group. Significant differences were observed in MCHC in fish fed with 100 mg/kg vitamin E compared to control and fish fed with 400 mg/kg, also treatment 200 mg/kg with treatment 400 mg/kg vitamin E (p<0.05). Fish fed vitamin E in 200 and 100 mg/kg had the highest WBC count. Fish fed with different levels of vitamin E had higher lymphocyte in comparison with control group and fish fed with 100 mg/kg had significant difference with control in lymphocyte (p<0.05). CONCLUSIONS: Vitamin E in level of 200 mg/kg can play an important role to enhance growth performance, nutrition efficiency and improving blood indices and support cell immunity in common carp fingerlings.