Publications by authors named "Zakaria A M Baka"

3 Publications

  • Page 1 of 1

Identification and Functional Analysis of Temperate Siphoviridae Bacteriophages of .

Viruses 2020 05 31;12(6). Epub 2020 May 31.

Department of Bacteriology and Immunology, Medicum, Human Microbiome Research Program, Faculty of Medicine, University of Helsinki, 00290 Helsinki, Finland.

is an opportunistic pathogen that presents a serious clinical challenge due to its increasing resistance to all available antibiotics. Phage therapy has been introduced recently to treat antibiotic-incurable infections. In search for new specific bacteriophages, 20 clinical strains were used in two pools in an attempt to enrich phages from sewage. The enrichment resulted in induction of resident prophage(s) and three temperate bacteriophages, named vB_AbaS_fEg-Aba01, vB_AbaS_fLi-Aba02 and vB_AbaS_fLi-Aba03, all able to infect only one strain (#6597) of the 20 clinical strains, were isolated. Morphological characteristics obtained by transmission electron microscopy together with the genomic information revealed that the phages belong to the family . The ca. 35 kb genomic sequences of the phages were >99% identical to each other. The linear ds DNA genomes of the phages contained 10 nt cohesive end termini, 52-54 predicted genes, an site and one tRNA gene each. A database search revealed an >99% identical prophage in the genome of strain AbPK1 (acc. no. CP024576.1). Over 99% identical prophages were also identified from two of the original 20 clinical strains (#5707 and #5920) and both were shown to be spontaneously inducible, thus very likely being the origins of the isolated phages. The phage vB_AbaS_fEg-Aba01 was also able to lysogenize the susceptible strain #6597 demonstrating that it was fully functional. The phages showed a very narrow host range infecting only two strains. In conclusion, we have isolated and characterized three novel temperate phages that infect .
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.3390/v12060604DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC7354433PMC
May 2020

Occurrence of Puccinia isiacae on Phragmites australis in Saudi Arabia and its possibility as a biological control agent.

Authors:
Zakaria A M Baka

Microbiol Res 2004 ;159(3):175-9

Department of Botany, Faculty of Science, University of Mansoura, Mansoura, Egypt.

During the summer of 2002, symptoms of rust disease were observed for the first time on Phragmites australis in Saudi Arabia. Light brown lesions of regular shape indicating uredinia of Puccinia isiacae appeared on the leaves. The morphology and characteristics of the fungus were described in detail with both light and scanning electron microscopy. The possibility of using this fungus as a biological control agent was also discussed.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.1016/j.micres.2004.01.015DOI Listing
November 2004

Ultrastructure of intercellular hypha and haustorium of the rust fungus, Uromyces euphorbiae.

Authors:
Zakaria A M Baka

Mycopathologia 2002 ;156(3):215-21

Department of Biology, Faculty of Science (31), King Khalid University, Abha 9004, Saudi Arabia.

The ultrastructure of intercellular hyphae and dikaryotic haustoria of Uromyces euphorbiae, and the host response to haustorial invasion was investigated. The intercellular hyphae share common characteristics with those of other uredinial stages of rust fungi. Three types of septa were recognized inside the intercellular hypha. This study showed that the extrahaustorial membrane was possibly formed before the development of the haustorium. The periodic acid-thiocharbohydrazide-silver proteinate technique showed that the haustorial mother cell wall at the penetration site, and the haustorial wall contained more carbohydrates than other fungal structures. In addition, the neckband, present around the haustorial neck, contains different material from those of the rest of the haustorial neck wall. The close associations of host organelles, such as the nucleus, chloroplasts, mitochondria, endoplasmic reticulum and microtubules, with the haustorium, is described.
View Article and Find Full Text PDF

Download full-text PDF

Source
July 2003
-->