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In the present study, each of the 16S ribosomal RNA (rRNA) gene sequences and random amplified polymorphic DNA (RAPD) method were used to confirm the biological classification of three Streptomyces isolates having antiviral activities against Tobacco mosaic virus (TMV). The strongest anti- TMV effect with an inhibition percentage of 97.5 was recorded for S. rochei- IS-02 followed by S. caeaoi-IS-03 (95.5%) and S. aureocirculatus-IS-01 (92.5%) at dilution ½. Lengths of 771, 663 and 693 nts were determined for the partial nucleotide sequences of 16SrRNA gene of S. aureocirculatus-IS-01, S. rochei-IS-02 and S. caeaoi-IS-03, respectively. Sequences producing significant alignments showed identities ranging from 98.41 to 100%. The phylogenetic relationship confirmed the identification of the Streptomyces isolates. A total of 85 DNA fragments (81 polymorphic and 4 monomorphic) were amplified in RAPD assay of the three Streptomyces isolates using eight random primers and contained unique DNA fragments as positive DNA markers. These DNA fragments were distributed as 48, 41 and 42 for the three isolates. The eight primers produced a total amplified DNA fragments of 85 distributed as follows 8, 10, 13, 12, 12, 10, 11 and 9 for the eight oligonucleotide primers, respectively. The similarities between the three Streptomyces species based on RAPD-PCR ranged from 66.332 to 76.158%. The phylogenetic tree showed that S. aureocirculatus-IS-01 and S. rochei-IS-2 were found together in the same cluster, while, S. caeaoi-IS-03 was found in a separate cluster. As a conclusion 16SrRNA and RAPD-PCR methods were confirmed to be more than suitable tools to differentiate between the Streptomyces species. [ABSTRACT FROM AUTHOR]

Copyright of Journal of Agricultural Chemistry & Biotechnology 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.)

Copyright of Journal of Animal & Poultry Production 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.)

Copyright of Journal of Agricultural Chemistry & Biotechnology 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.)

In the present study, two molecular biology tools based on DNA were compared in the differentiating between some microbial strains isolated from soil. Two types (16SrRNA and 18SrRNA) of ribosomal RNA genes were used for identification of the four bacterial and three fungal isolates, respectively. The identified microbial isolates were submitted in GenBank as strains of Escherichia coli MSL-19 (LC455952.1); Bacillus sp. MSLB-1 (LC455953.1); Bacillus sp. MSLB2 (LC455954.1); Bacillus sp. MSLB3 (LC455955.1); Penicillium sp. MLSP1 (LC455956.1); Aspergillus niger MLSAs1 (LC455958.1); Aspergillus sp. MLSAs2 (LC455959.1). The DNA obtained from the seven microbial strains was used as templates for RAPDPCR differentiating in the presence of eight random primers. Electrophoresis analysis was performed, and on scoring, the identity percentages between the bacterial and fungal strains were separately analyzed. A percentage of 82-83% was recorded between the E. coli and the three Bacillus strains, while, identities of 93-98% were recorded between the three Bacillus strains. Similar trend (90-96%) was observed between the Penicillium and Aspergillus strains. Results confirmed that identities based on the two ribosomal RNA genes (82-98%) was higher than that of RAPD-PCR (70.0-79.7%), and this is because of ribosomal RNA genes are in limited sizes (~1500-1600 bp) and specific for differentiating species, while RAPD-PCR tool depends on using some random primers could be recorded on the whole genome. The phylogenetic trees based on the two molecular tools supported the obtained results. As a conclusion, tools of RAPD-PCR and ribosomal RNA genes were successfully used to identify and detect the genetic variability of microbial strains isolated from soil. [ABSTRACT FROM AUTHOR]

In the present study, a trail to evaluate of Newcastle Disease (ND) antibodies levels after different vaccination programs was conducted on layer chickens. A total of 200 one day-old layer chicks (White Lohmann) were divided into five groups A, B, C, D and E. Birds in groups A, B and C were vaccinated with live vaccine by intraocular, intranasal and drinking water methods , respectively. On the other hand, groups D and E were kept as unvaccinated control groups. Vaccination performed at days 5, 18 and 28 by different routes for mentioned groups. Hemagglutination inhibition (HI) and enzyme-linked immunosorbent assay (ELISA) methods were used for assessment of antibodies titer at days 15, 25, 37 and 45. Results of HI and ELISA tests indicated that, the intranasal and the intraocular method have highest antibodies titers compared with the drinking water method. In this study, maternally derived antibodies specific to Newcastle Disease Virus (NDV) (IgY) were extracted by dextran sulfate method from collected eggs of vaccinated laying chickens . Antibodies specific to NDV (IgY) were detected in the egg yolk using HI test . Data revealed that antibodies specific to NDV (IgY) were presented in high titers that confer protection during early weeks of life for hatching chicks. Data concluded that extraction of maternally derived specific antibodies from egg yolk will facilitate accurate monitoring of ND vaccination programmes. [ABSTRACT FROM AUTHOR]

Listeria monocytogenes is a food borne pathogenic bacteria and caused a dangerous infection of humans. Six lytic bacteriophages specific to L. monocytogenes were isolated from irrigation and sewage waters and named ØLG, ØLA, ØLM, ØLD, ØLN and ØLP. The phages were propagated, and then purified by the ultracentrifugation. Morphological properties of Listeria phages showed that the phages were tailed phages, varied in their sizes and assigned to be a member of Siphoviridae (ØLG, ØLA, ØLM) and Myoviridae (ØLN, ØLD, ØLP) families. All Listeria phages were highly stable under different temperature conditions and its thermal inactivation point was reached to 80°C. The longevity in vitro of the phages was up to 60 days, as well as phages were active at pH values ranging from 4.0 to 12.0. Listeria phages did not lose their infectivity after exposure to UV for 90 min at 35 and 53 cm distances. Results of SDS-PAGE showed that phages had 5-6 protein fragments with molecular weights of 66, 45, 37, 35, 33 and 28 kDa distributed among the six phages. [ABSTRACT FROM AUTHOR]

Copyright of Egyptian Journal of Experimental Biology (Botany) is the property of Egyptian Society of Experimental Biology 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.)