نشریه میکروبیولوژی دامپزشکی
سال چهاردهم شماره 2 (پیاپی 37، پاییز و زمستان 1397)

The aim of this study was investigating the effect of antibiotic (sodium monensin) and trade probiotic on fermentation process and estimation of gas production parameters of feedstuffs (alfalfa hay, barley grain and alfalfa+ barley 50:50) in vitro condition. Experimental treatments were included control treatment (basal feeds without additive), basal feeds
supplemented with sodium monensin antibiotic and the trade probiotic at levels of 500 and 1000 mg per kg of DM. Gas production in vitro was used for determining gas production
parameters. Results showed both levels of sodium monensin and 1000 mg/kg of monensin decreased fermentable fraction (b) and rate (c) of gas production of alfalfa, respectively. Also, rate (c) of gas production of barley was significantly decreased by supplying a higher level of monensin (1000 mg/ kg). In comparison with level of 500 mg/kg probiotic, the higher level of probiotic increased rate of gas production of alfalfa+ barley mixture. There was no significant (p>0.05) effect of treatments on organic digestibility and metabolisable energy. Supplementation of antibiotics in diet containing 100% hay decreased fermentative parameters of feedstuffs in rumen. Adding the higher level of monensin to diet containing 100% grain decreased significantly gas production rate. Using probiotics in diet containing mixed hay and grain can increase rate of gas production by stimulating ruminal bacteria.

The probiotic products consumption especially yogurt is very prevalent. Gundelia tourneforti is one of plants that have several beneficial effects. In this study the effect of this plant
hydroalcoholic extract and kefir probiotic on bacteria Lactobacillus acidophilus and Bifidobacterium bifidum growth in yogurt were investigated. The probiotics products were
produced by Tamime standard method. Then the products were investigated sensory, pH, acidity and microbial count in incubation and maintenance term. The data were analysis by
descriptive statistical test with SPSS system. The results of this study showed the time has a negative effect on pH and a positive effect on acidity, so that time increased causes pH decreased and acidity increased. The bacterial count was 1010 cfu.ml in incubation term and remained in this count in maintenance period almost.  The investigation of the results revealed, kefir and Gundelia tourneforti hydroalcoholic extract concentration increased have positive significant effects on Lactobacillus acidophilus and Bifidobacterium bifidum. In sensory evaluation turned out yogurt containing 0.6 gr Bifidobacterium bifidum and 0.6 gr Lactobacillus acidophilus gained superlative and lowest score respectively.

Propolis is one of the byproducts of bees. Biological activities of propolis is related to geographical and botanical origion. The aim of this study was to evaluate the antibacterial and antioxidant activity the three types of propolis with different geographical origion from Golestan province in northern Iran.The evaluation of antibacterial activity by using agar well diffusion method was performed. Minimum inhibitory concentration (MIC) and minimum bactericidal concentration (MBC) of propolis samples were determined by using broth macrodilution tube method. Also the total phenolic content (TPC), total flavonoid content (TPC) and free radical scavenging activity of propolis samples were determined. Grampositive bacteria compared to gram-negative bacteria showed more sensivity to different concentrations of propolis samples. As MIC of propolis collected from the geographic region of the Shast Kola for B. cereus and S. aureus was, 0/048 and 0/19 mg/ml respectively and for S. dysentery and E.coli 3.12 and 3.12 mg/ml respectively. Propolis sample of JahanNama area with mean of 142.67 mgGAE/g sample and 35.24 mgQE/g sample showed highest TPC and TFC. The highest DPPH radical scavenging activity was related to Shast Kola propolis sample. The antibacterial activity of propolis samples had direct correlation with phenolic
and flavonoid content. The total phenolic and flavonoid content had negative correlation with free radical scavenging DPPH, explain that the antioxidant activity of propolis also is related to other components. So the identification of other compounds of propolis is recommended.

The aim of this study was to investigate the antibacterial effect of the recombinant camel Lactoferrampin-Lactoferricin on the growth rate of Staphylococcus aureus bacteria, one of the causes of mastitis in dairy cows. This peptide, which was prepared through a previous study in Biotechnology Laboratory of Animal Science Department, Faculty of Agriculture, Ferdowsi University of Mashhad. Antibacterial effects of this peptide was assessed by Count Colonies on Methicillin-resistant Staphylococcus aureus )PTCC 1764( and Staphylococcus aureus )ATCC 25923(. Heat resistance properties and freeze drying process of the peptide were evaluated by disk diffusion method in triplicate. The results showed that this recombinant peptide had an antibacterial effect on Staphylococcus aureus (p<0/0001), but had no effect on methicillin-resistant Staphylococcus aureus. Heat resistant of the recombinant peptide also showed that 100 °C temperature for 40 minutes had no significant effect on the anti-bacterial properties of this protein (p<0/0001). This protein showed no loss of activity after freeze drying process. The results obtained from this study proved the stable activity of natural peptides as well as antibacterial properties. This recombinant peptide can be used as an alternative to antibiotics or a therapeutic supplement to cure mastitis in dairy
cows.

Broilers are one of the potential sources of bacterial infections particularly Escherichia coli infections in human. Different studies have previously showed genetic similarities between
APEC (avian pathogenic E. coli) strains and human pathogen strains of the microorganism. In this study we evaluate the presence of the fimH virulence gene among human and broiler
isolates of E. coli. In addition the antibiotic susceptibility of the strains was investigated. After collection and identification of the isolates (including 26 human isolates and 60 broilers isolates), at first, total DNA of the pure microorganisms was extracted using boiling method and then DNA samples were subjected to PCR using specific primers for fimH gene. Antibiotic resistance pattern was evaluated by disk diffusion methods for 14 different antibacterial agents. Among 86 E. coli isolates, the fimH gene was detected in 53 (61.62%) isolates. In addition, the isolates showed high resistance to oxacilin (93.02%), colistin (91.86%) and cephalexin (89.53%) respectively. According to the results, the prevalence of the fimH gene among human isolates was significantly (P<0.05) higher than avian isolates. In total, 70 different antibiotic resistance patterns were observed among isolates which showed that there are significant differences between the resistance patterns of different isolates with different sources. It can be due to the use of various antibiotics in treating the complications of this bacterium in humans and livestock.

In the present study, in which the main goal was to determine the prevalence of RSV infection in goats slaughtered in Garmsar slaughterhouse, a total of 402 goat were subjected to postslaughter inspection. Among them, 67 (16.7%) cases were found having macrosdopic lesions of pneumonia particularly on the cranioventral lobs. Lesions were more frequently encountered in anteroventral lobes than caudal lobes. With the exception of 18 cases in which parasitic pneumonia and catarrhal and purulent bronchopneumonia were observed, the remaining 49 cases with macroscopic lesions of interstitial pneumonia and bronchointerstitial pneumonia used for RSV antigen detection. Formalin-fixed and paraffin-embedded lung tissue samples were immunohistochemically stained using routine avidin-biotin-peroxidase complex techniques to detect RSV antigens. In the present study, out of 49 cases with interstitial pneumonia and bronchointerstitial pneumonia, in 9 cases (18.36%) RSV viral antigens was detected, which were mainly found in the cytoplasm of bronchiolar epithelial cells, type II pneumocytes, and less frequently in the epithelial cells of bronchial glands, syncytial cells, alveolar macrophages, and lymphocytes and plasma cells. In conclusion, despite of the determining the prevalence of RSV viral antigens in pneumonic lungs of goats in the Garmsar region, a possible role of RSV in the induction of interstitial pneumonia in goats was suggested.

In order to prevent or inhibit the growth of pathogenic objects and factors of food spoilage, great deal of research has been done by using natural preservatives and currently is performed. This study has been done to investigate the effect of different concentrations of lysozyme and nisin on the growth rate of the bacteria Escherichia coli and Listeria monocytogenes and also  determination of MIC and MBC of this combinations on these bacteria.In this study, various concentrations of lysozyme and nisin was set in form of alone concentration and in combination concentration (0, 19.53, 39.06, 78.13, 156.25, 312.5, 625, 1250, 2500, 5000) in vitro conditions and pH 5.5, 6, 6.5, 7, 7.5 and 8.These actions was done in microdilution method at 24 ° C and reading the combined effect on the growth of bacteria was performed by using ELISA reader.The results showed that lysozyme is less effective on the E. coli and nisin have less effective on the L.monocytogenes. The combined use of lysozyme and nisin at low pH was decreased MIC.

Fish mycobacteriosis is a chronic progressive disease that caused by different species of mycobacteria. Diagnosis of the disease in ornamental fish is usually done by bacterial culture and histopathology. Identification is also based on the rate of growth at different temperature, the pigmentation type, the morphology of colony and by biochemical tests. Although the primary diagnosis of fish mycobacteriosis is based on clinical symptoms and the presence of granuloma in visceral tissues by sampling, but in some cases no any clinical symptoms or no granulomas masses are seen. Due to the zoonotic character of the disease, increasing importance of aquariology, and also increasing of opportunistic infections via Non-tuberculous mycobacteria in older persons or immunocompromised patients, also existence of some extremely difficulties to treat like to require the long course of therapy, and on the other hand, the financial losses, so; the present study planned to detection and identification of mycobacterial species in aquarium fish. Existence of Mycobacterial species in 53 fishes were investigated that they were obtained from some local aquarium shops in Tabriz by Ziehl-Neelsen staining and culture on Lowenstein-Jensen (LJ) medium. Identification of isolates was done by morphological characters of mycobacteria on LJ and using of biochemical tests. For drug susceptibility testing, the proportional method on LJ were used for isoniazid, ethambutol, rifampin, streptomycin, kanamycin, ciprofloxacin, and amikacin. The susceptible (H37Rv) standard Mycobacterium tuberculosis strain was used as a control. Acid-fast bacilli were detected on the 7 smears of samples by direct microscopic examination of Ziehl-Neelsen. In using of the culture method, Mycobacterium spp. were isolated from 28.3% of the fishes. The isolated species were identified as M. marinum, M. fortuitum, M. smegmatis, M. terrea, M. flavescens and M. asiaticum. The study showed that M. fortuitum and M. marinum are more than other species. In the drug susceptibility testing; the streptomycin had the highest resistance (93.33%) and the lowest drug resistance was diagnosed to ciprofloxacin (20%). In the investigation, Mycobacterium marinum, M. fortuitum, M. smegmatis and M. flavescens that are well known as pathogens in fish and humans were isolated, which were resistant to most drugs that are used in the treatment. Therefore, more attention should be paid to the presence of
mycobacteria in aquarium fish for reducing the rate of bacterial transmission to human.

In this study, the effect of different species of isolated Lactobacillus from cattle and buffalo feces from some Urmia suburban farm were investigated on cholesterol reduction efficacy in
the test tube. Bacteriological studies on cow fecal sample showed that 5 different species of Lactobacillus were able to grow on MRS agar medium. The most frequently isolated species was Lactobacillus rhamnosus (37/5%) and Lactobacillus fermentum and lactobacillus delbrueckii were the less abundant organisms (5%). Bacteriological examination on buffalo fecal sample revealed, ten different species of Lactobacillus and one species of Bifidobacterium were isolated. The higher and lower frequency microrganisms were Lactobacillus acidophilus (25%) and Lactobacillus bulgaricus (2/28%) respectivelly. In this study, the ability of bacteria isolated from fecal samples to reduce cholesterol level in MRS broth medium was considered. It’s should be concluded that non of isolated Lactobacilli from cow fecal samples could modify cholesterol level in test tube, while some of bacteria isolated from buffalo feces could reduce cholesterol level in medium after 24 hours. Depended on bacteria species, this reduction is variable, and the most reduction related to Lactobacillus paracasei (50%), and the less reduction related to Lactobacillus casei (12%).

Saccharomyces cerevisiae as a supplementary prebiotic in experimental diets on some of the blood indices and liver enzymes of Cyprinus carpio fingerlings. For this purpose, a number of 600 fish fry with an average mean (±SD) weight of 5.1±0.85 g were obtained and transferred to the laboratory. After 7 days adaptation to the new conditions the fish fry were randomly divided into 12 polyethylene tanks and kept at a density of 50 fish fry in per tank for 60 days. Four levels of cell wall of yeast S. cerevisiae as 0 (Control), 0.4 (F1), 0.8 (F2) and 1.2 (F3) g.kg-1 were used with triplicates. At the end of the experiment, blood samples were collected from the caudal vein of 15 fish (with average mean weight of 25±1.3 g) of every tank apparently healthy fish to determine some of hematologic parameters and serum enzymes (alkaline phosphatase, alanine aminotransferase and aspartate aminotransferase) in different groups and compared to one another. Our results showed that the cell wall of yeast S. cerevisiae had no significant discrepancy was observed in monocyte, lymphocyte counts and MCV value between the prebiotic treatment and control group (p>0.05). Nevertheless, leucocyte counts (WBC), red blood cell counts (RBC), hemoglobin (Hb), hematocrit (HCT), MCH, MCHC values and neutrophil counts, in fish fry fed cell wall of yeast S. cerevisiae as a prebiotic were significantly compared with the control group (p<0.05). Also, the result showed that the cell wall of yeast S. cerevisiae had significant effects on serum alanine aminotransferase and alkaline phosphatase compared with the control group (p<0.05). While, analyses of the results did not show any significant differences in the amount of aspartate aminotransferase enzyme in experimental treatments and control group (p>0.05). Based on these results, we could claim that the use of the cell wall of yeast S. cerevisiae in experimental diets of fingerlings carps have different performance on hematology parameters and may enhance the non-specific immune system of the immunomodulatory
effect on fingerlings carp.