فهرست مطالب sara basiri

Climate change is the twenty-first century's most significant threat to human health. Human activity has led to a gradual increase in greenhouse gas concentrations, resulting in global warming and other related hazards. Climate change is significantly impacting ecosystems and biodiversity, leading to a potential increase in zoonotic diseases. Zoonoses are infectious diseases that are transmitted among animals and humans. Vector-borne, foodborne, and waterborne diseases are major infectious diseases associated with climate change. Changes in temperature and precipitation patterns influence the survival, reproduction, and activity of disease-carrying vectors like mosquitoes, ticks, and sandflies. Variations in climate can affect the spread of diseases such as malaria, leishmaniasis, and rodent-borne illnesses like leptospirosis, bartonellosis, plague, and hantavirus infections. Climate change can also impact waterborne illnesses by altering water quality and increasing the risk of contamination during natural disasters. Additionally, higher temperatures and increased humidity can cause transmission of airborne zoonotic diseases, such as aspergillosis, tuberculosis, and influenza. The evolving climate may also contribute to the development of resistance in disease-causing microorganisms, making treatment more challenging. Human behavior influenced by climate change, such as changes in agricultural practices and land use, can indirectly affect disease transmission by altering vector habitats and human-animal interactions. Overall, the complex interplay between climate change, ecological factors, and human behavior underscores the need for comprehensive strategies to mitigate the risks posed by zoonotic diseases and protect public health.

This study was performed to compare the sensitivity of seven plate methods and commercial kits for the detection of antibiotics in vitro and in poultry carcasses. In the first step, different concentrations of five commonly used antibiotics in poultry breeding were prepared and the sensitivity of both methods in antibiotic residue detection was evaluated. Subsequently, 20 days old broilers were divided into 5 groups. After an adaptation period and feeding non-antibiotic diet, groups were treated with therapeutic doses of Oxytetracycline, Enrofloxacin, Florfenicol, and Fosfomycin through drinking water. One group was considered as a control. At antibiotic discontinuation day (day 0) and days 1, 2, 3, 4, 5, and 6 thereafter, 3 chicks from each group were slaughtered and thigh muscle, liver and kidney were sampled and residual antibiotics were evaluated by both methods. The results showed that sensitivity of commercial kits was higher in in-vitro condition than that of poultry carcass. In the seven plate method, the residuals were more detectable in the liver and kidney. The commercial kit was able to detect antibiotics only up to 24 hours, after which almost all specimens were negative. The seven plate method was positive for most of the specimens up to three days after discontinuation.  This study showed that the efficacy of the seven-plate method was more than commercial kits, and in order to increase the efficiency of detection methods, it is recommended to perform it on the liver and kidney of four carcasses from each herd (total of 8 samples). If at least four samples are positive, the herd is considered as infected and the HPLC method is used to confirm the specimens.

Exopolysaccharides (EPSs) are high molecular weight polysaccharides secreted by microorganisms in the surrounding environment. In addition to the favorable benefits of these compounds for microorganisms, including microbial cell protection, they are used in various food, pharmaceutical, and cosmetic industries. Investigating the functional and health-promoting characteristics of microbial EPS, identifying the isolation method of these valuable compounds, and their applications in the food industry are the objectives of this study. EPS are used in food industries as thickeners, gelling agents, viscosifiers, and film formers. The antioxidative, anticancer, prebiotic, and cholesterol-lowering effects of some of these compounds make it possible to use them in functional food production.

Salmonellosis is well known as a severe problem of all bird species, as well as humans, which is considered as one of the most common infectious diseases in pigeons. In the present study, a homing pigeon flock was referred with non-specific clinical signs such as diarrhea, progressive weight loss, weakness, drooping wings associated with a 21.05% mortality rate. At necropsy, severe necrotic hemorrhagic enteritis was found together with severe dehydration and pectoral muscle atrophy. In order to investigate the possibility of Salmonella infection, bacterial examinations were performed on Brilliant Green (BG) agar, Xylose-lysine deoxycholate (XLD) agar, and Salmonella-Shigella (SS) agar plates. Besides, biochemical tests were conducted to confirm Salmonella identification. Moreover, tissue samples were taken for histopathological examination. The results of bacteriological examinations showed the presence of Salmonella Typhimurium through Salmonella colonies on the applicable media, Gram stain smears, and biochemical analysis. At histopathological studies, which consistent with the bacteriological findings, severe enterocyte necrosis, heterophil infiltration, and hemorrhage were observed in the intestinal mucosa. Moreover, there was vascular congestion together with focal necrosis and inflammation in the liver, kidney, and spleen. In conclusion, it seems that infection by S. Typhimurium is frequently occurring in pigeons by diarrhea and enteritis. Thus, it should be considered in relation to public health

The aflatoxin M1 (AFM1) is present in the milk of livestock fed on contaminated feed. This study was conducted based on the fact that milk is one of the main sources of aflatoxin contamination in human. In order to record the frequency of AFM1, a total of 207 milk samples including 153 raw milk samples from 12 different regions of Kerman province and 54 pasteurized milk samples produced in 10 dairy factories of Kerman province were checked by Elisa. Results showed that the concentration of AFM1 in 41.2% of raw and 35.2% of the pasteurized samples was above the maximum acceptable level (100 ng/L) approved by National Institute of Standard, Iran. The amount of AFM1 in pasteurized milk was significantly lower than that in the raw milk. In order to confirm the results of ELISA, 24 samples of raw milk and 2 samples of pasteurized milk were also evaluated by HPLC, from which, four positive and five negative samples were finally confirmed. Although there was no significant correlation between the number of positive and negative samples in both methods, the concentration of AFM1 was significantly correlated. The sensitivity and the specificity of the ELISA test was respectively 100% and 25%. Since the concentration of aflatoxin was higher than the accepted level, a proper strategy of feeding management of the dairy farms in the province are suggested. In spite of the fact that ELISA is a suitable method for screening of AFM1, using a method with higher specificity is also recommended.

The intestinal microflora has an important role in the health status. Since probiotics can balance the intestinal microflora, they have a lot of health beneficial effects. So the appropriate selection of probiotics can cause health-promoting effects. In this study, the combined effects of Bacillus subtilis and Bacillus coagulans on the intestinal microflora and growth performance in rats were investigated. 80 male rats were divided into the treatment (receiving 5×107 spores/ml of B. subtilis and 5×107 spores/ml of B. coagulans for three weeks in daily water) and control (tap water without probiotics) groups. The total aerobic and anaerobic microorganisms, lactic acid bacteria (LAB), coliforms and spores were weekly counted in the fecal samples. Additionally, the water and feed consumption, the weight gain and Feed Conversion Ratio (FCR) were calculated for each week. The probiotics significantly increased the total aerobic, LAB and spore counts and caused significant reduction in the anaerobe and coliform counts. Following three weeks of probiotic administration, the number of anaerobic bacteria, and coliforms were reduced by up to 0.7 and 1.18 log and the number of aerobic bacteria, LAB and spores were increased by 1.29, 1.15 and 7.2 log respectively. Also, the results showed the feed consumption reduction, weight gain and FCR enhancement in the probiotic group (p < 0.05). Supplementation the spores of B. subtilis and B. coagulans improved the growth performance and was beneficial to the intestinal microbiota in rats.