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Aeromonas isolates from Nile tilapia fish, fish ponds and River water were identified as well as their bacteriophage specific. Also evaluation of antibacterial effect of both nanoparticles and phage therapy against the pathogenic Aeromonas veronii AFs2. Differentiation of Aeromonas spp. was done on the basis of 25 different biochemical tests and confirmed by sequencing of 16s rRNA gene as (A. caviae AFg, A. encheleia AWz, A. molluscorum AFm, A. salmonicida AWh, A. veronii AFs2, A. veronii bv. veronii AFi). All of the six Aeromonas strains were resistant to β-actam (amoxicillin/ lavulanic acid) antibiotics. However, the resistance to other antibiotics was variable. All Aeromonas strains were found to be resistant to ampicillin, cephalexin, cephradine, amoxicillin/clavulanic acid, rifampin and cephalothin. Sensitivity of 6 Aeromonas strains raised against 7 concentrations of chitosan nanoparticles. Using well diffusion method spherically shaped silver nanoparticles AgNPs with an average size of ~ 20 nm, showed a great antimicrobial activity against A. veronii AFs2 and five more strains of Aeromonas spp. At the concentration of 20, 24, 32 and 40 μg/ml. Thermal inactivation point was 84oC for phage AvF07 which was sensitive to storage at 4oC compared with the storage at - 20oC. Intraperitoneal injection in fish using phage AvF07 together with A. veronii AFs2, no mortality was shown until the end of experiment (14 days). However, mortality of 43.8% or 50% was obtained after 2 or 3 days, respectively, when chloramphenicol was injected instead of phage. [ABSTRACT FROM AUTHOR]

Copyright of Zagazig Journal of Agricultural Research is the property of Egyptian National Agricultural Library (ENAL) and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Prodigiosin is a natural red pigment, it is an alkaloid secondary metabolite with a unique tripyrrole structure produced by Serratia marcescens, it’s motile, short-rod shaped, G- bacteria, classified in the large family of Enterobacteriaceae. 13 isolates were isolated from 32 soil samples, which showed clear red pigmented colonies. The Egyptian Serratia marcescens isolates were identified based on morphological, biochemical and then only the two best isolates for pigment production (M1, S1) were identified by MALDI-TOF mass spectrometry technique. The two selected species gave a score value between 2.565 to 2.668 (100%) were correctly identified by MALDI-TOF- MS to the genus and species levels. The average daily rate of pigment production by M1 and S1 isolates estimated by 421.6 and 326.1 unit/cell, respectively. Antibacterial activity of prodigiosin was determined by disc diffusion assay against 7 types of G- and 4 types of G+ pathogenic bacteria. Minimum inhibitory concentration (MIC) and the concentration inducing 50% inhibition of the bacterial growth (IC50) against the mentioned bacteria were determined and prodigiosin was proved to be effective in inhibiting bacterial growth. Prodigiosin possess antioxidant activity assayed by 2,2- diphenyl-1-picrylhydrazyl (DPPH) reduction method and this activity increased gradually with increasing concentrations. [ABSTRACT FROM AUTHOR]

Copyright of Zagazig Journal of Agricultural Research is the property of Egyptian National Agricultural Library (ENAL) and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Forty pathogenic isolates were isolated from patients from hospital's Zagazig University which having skin wounds. Morphological and biochemical identification of the tested isolates showed that twenty isolates were identified as bacterial isolates from total forty microbial isolates .The isolates No. 2,3,4,7,9, 10,11, 12,14, 15,16,17, 18,19, and 20 (75%) were identified as Staphylococcus aureus. Four isolates were choosen to be identified by Bruker Daltonik MALDI Biotyper. Due to high resistance of most tested isolates to antibiotics especially Ampicillin (100%), alternative treatment methods that are safe and effective were used, so plant extracts were used as they were safe materials and have good effects. In this study, antibacterial activity of (methanolic, acetone, and aqueous) some plant extracts of (Cymhopogon citratus, Rosmarinus officinalis, Salvia officinalis, Achillea millefolium, Mentha spicata var viridis, Mentha piperita, Magorana hortensis (Origanum Majorana), Nigella saliva, Phyllanthus emblica L. (syn. Emblica officinalis), Tulbaghia violacea ) were performed against tested isolates by using disk diffusion assay method. Most plant extracts exhibited notable antimicrobial activites against most of the tested Staphylococcus aureus isolates. The plant extract of Rosmarinus officinalis was the most effective against all S. aureus isolates and its antibacterial effect was investigated by using electron scanning microscopy. The treated cells were appeared shrinked, tiny, dehydrated and the entire bacterial cells were fully lysed, the interior dehydrated cellular components and debrises were the only observable matrix. It could be suggested that at this stage, the bacterial cells completely lost all their metabolic functions. Also, Rosmarinus officinalis methanolic extract loaded on Vaseline gauze showed antibacterial activity against the tested isolate (Si) with inhibition zone 2.8 mm, but the inhibition zone of plant extract and antibiotic (Ciprofloxacin) loaded together on Vaseline gauze against the same isolate was higher than each of them (3.3 mm). Vaseline gauze that was treated with only antibiotic didn't have any effect against the tested isolate. [ABSTRACT FROM AUTHOR]

This study was performed to evaluate the impact of phytohormones indole-3- butyric acid and gibberellic acid (IBA and GA3) on 6 indigenous species of microalgae. isolated from different regions in Sharkia Govemorate, Egypt, in terms of their dry weight, lipids and protein contents. Lipids were measured after ethanol-chloroform extraction, and proteins were measured by micro-Kjeldahl method. In general, all treatments of IBA gave positive effects on biomass dry weight, total lipids and protein contents compared to control except high level of IBA (20 mg/I medium). On the contrary, most concentrations of GA3 gave negative results in all microalgal cultures. The increase in biomass dry weight, total lipids and protein contents due to phytohormones treatments has reached 3.4 times in biomass, 3 times in total lipids, and 3.5 times in total protein contents. In biomass dry weight, the highest responses were found in the Chl01'ella vulgaris MG 14 340% to IBA treatment of 15 mg/I, followed by Ch/ore/la vulgaris MG30 329% under the same treatment. The highest value for each of total lipids and proteins for Ch/ore/la vulgaris MG 14 were 300% and 351 %, respectively in response to 15 mg/I treatment. In general, it is most likely that phytohormones may be considered as a promising tool in maximizing the exploitation of microalgal cultures in biomass and biodiesel production. [ABSTRACT FROM AUTHOR]

The present study was carried out in the laboratory of agricultural microbiology Department, faculty of agriculture, Zagazig University, Egypt, in summer and winter seasons 2013 and 2014. In order to study the aflatoxin Ml (AFM1) contamination in milk, kareish cheese and yoghurt. AFMI was detected in raw milk in only 10 out of 12 samples (83.3%) in each season. Winter season had higher AFMI concentration than summer season with the mean values of 311.8 and 207.0 ng/1, respectively. AFMI was detected in all samples of kareish cheese (24 samples) in summer as well as in winter season. Winter season had higher AFMI concentration than summer season with average values of 651.36 and 527.40 ng/kg, respectively. The present results observed that 83.33% of cheese sample examined exceeding the limits of EU (50 ng/kg), and (70.83%) of cheese samples examined exceeding the limits of codex (500 ng/kg) in both summer and winter seasons. In yoghurt, the AFMI did not detect in 3 out of 12 samples of yoghurt tested. In summer season the positive samples ranged from 31.46 to 66.05 ng/kg with average of 39.13 ng/kg. AFMI did not detect in only one out of 12 samples tested in winter season. Also, the positive samples ranged from 56.6 to 84.14 ng/kg with an average of 64.68 ng/kg. Cheese had a higher concentration of AFMI than both raw milk and yoghurt. Also, yoghurt had the lowest concentration of AFMI comparing to raw milk and cheese. Heating treatments reduced the concentrations of AFMI in all raw milk samples tested. Boiling caused 26.71 % degradion of AFMI, whereas pasteurization caused only 15.45% degradation. In yoghurt, two strains of probiotic bacteria (lactobacillus acidophilus and Bifidobacterium lactis) individually were gradually reduced the concentration of AFMI in contaminated milk with 25 ppt, as a function of time with complete elimination by the end of storage period (3 days) at refrigerator, while the cocktail of the two strains showed more ability for reducing AFMI. Both probiotic bacteria (L. acidophilus and B. lactis) showed more ability for reducing AFMI in contaminated milk with 50.0 ppt or 75 ppt.The most important reductions of AFMI concentration were 41.80 ppt (45.3%), 2.6 ppt (69.90%) and 7.12 ppt (92.8%) which achieved by using the same concentration individually of each strain and in combination, respectively, in contaminated milk with 75ppt after two days. No AFMI was detected using combined strains after three days. [ABSTRACT FROM AUTHOR]