Youssuf Gherbawy

Prof. Youssuf Gherbawy


Research Focus & Metrics

Academic Career Length

29Years (1998-Present)

(Calculated once Scilit publication data is synced: current year − year of first publication + 1)

Representative Publications

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1 March 2013 in Journal of Plant Interactions
Verified
Journal Article
Open access
BEBahig El-Deeb
Bahig El-Deeb
KFKhalaf Fayez
Khalaf Fayez
YGYoussuf Gherbawy
Youssuf Gherbawy
The diversity and beneficial characteristics of endophytic microorganisms have been studied in Plectranthus tenuiflorus medicinal plant. However, information regarding naturally occurring P. tenuiflorus plant associated endophytes among different organs of host is limited. Endophytic bacteria were isolated from root, stem, and leaves of P. tenuiflorus plant. Among 28 endophytic bacterial isolates from different organs of P. tenuiflorus plant, 8 isolates were identified by partial sequencing of their 16S rRNA gene. The isolated endophytic bacteria were Bacillus sp., Bacillus megaterium, Bacillus pumilus, Bacillus licheniformis, Micrococcus luteus, Paenibacillus sp., Pseudomonas sp., and Acinetobacter calcoaceticus. The most isolates that exhibited extracellular enzymatic activity were belonged to the genus Bacillus. Furthermore, Bacillus sp. (HE613660) exhibited the stronger activities in extracellular enzymes such as amylase, esterase, lipase, protease, pectinase, xylanase, and cellulase than other strains. Considerable antimicrobial activities against a panel of human pathogenic microorganisms (Staphylococcus aureus, Escherichia coli, Klebsiella pneumoniae, Streptococcus agalactiae, Proteus mirabilis, and Candida albicans) were recorded using crude extracts of the collected endophytic strains.

1 September 2011 in Foodborne Pathogens and Disease
Verified
Journal Article
Closed access
SHSabry Hassan
Sabry Hassan
AAAbdullah D. Altalhi
Abdullah D. Altalhi
YGYoussuf Gherbawy
Youssuf Gherbawy
BEBahig A. El-Deeb
Bahig A. El-Deeb
This study was carried out to describe the bacterial load and the occurrence of some disease-causing enteric bacteria on raw vegetables sold in Saudi markets. The study further aimed to analyze antibiotic resistance rates, production of extended-spectrum beta lactamase, and plasmid carriage among bacterial population of raw vegetables. Results revealed that none of them contained Bacillus cereus, Salmonella , and Escherichia coli O157:H7. However, Staphylococcus aureus and Shigella were detected in 11.8% and 4.4% of the samples, respectively. The bacterial loads ranged from 3 to 8 log 10 CFUg −1 for aerobic bacteria and 1 to 4 log 10 CFUg −1 for coliforms as well as Enterobacteriaceae. The isolates exhibited resistance in decreasing order for ampicillin (76.5%), cephalothin (69.5%), trimethoprime-sulfamethoxazole (36.7%), aminoglycosides (21.9%), tetracycline (17.2%), fluoroquinolones (17.2%), amoxycillin-clavulanic acid (13.3%), and chloramphenicol (7.8%). Maximum resistance to extended-spectrum beta-lactam antibiotics occurred in 14.8% of isolates and the production of extended-spectrum beta-lactamase was achieved by 2.3% of isolates. Multiple resistances to four or more antimicrobial agents along with plasmid with varied sizes were documented. These investigations indicate the occurrence of antibiotic resistance and plasmid carriage among bacterial isolates populating raw vegetables.

1 January 2003 in Microbiological Research
Verified
Journal Article
Closed access
MWMichael Wuczkowski
Michael Wuczkowski
IDIrina Druzhinina
Irina Druzhinina
YGYoussuf Gherbawy
Youssuf Gherbawy
BKBrigitte Klug
Brigitte Klug
HPHansjörg Prillinger
Hansjörg Prillinger
CKChristian P. Kubicek
Christian P. Kubicek

23 July 2007 in Plant Pathology
Verified
Journal Article
Closed access
PDF file
GBG. L. Bateman
G. L. Bateman
RGR. J. Gutteridge
R. J. Gutteridge
YGYoussuf Gherbawy
Youssuf Gherbawy
MTM. A. Thomsett
M. A. Thomsett
PNP. Nicholson
P. Nicholson

Verified
Journal Article
Open access
PDF file
YGYoussuf Gherbawy
Youssuf Gherbawy
ISIsmail M. Shalaby
Ismail M. Shalaby
MEMahmoud Sayed Abd El-sadek
Mahmoud Sayed Abd El-sadek
HEHesham M. Elhariry
Hesham M. Elhariry
ABAbdelElah A. Banaja
AbdelElah A. Banaja
Recently, new strains of Fasciola demonstrated drug resistance, which increased the need for new drugs or improvement of the present drugs. Nanotechnology is expected to open some new opportunities to fight and prevent diseases using an atomic scale tailoring of materials. The ability to uncover the structure and function of biosystems at the nanoscale, stimulates research leading to improvement in biology, biotechnology, medicine and healthcare. The size of nanomaterials is similar to that of most biological molecules and structures; therefore, nanomaterials can be useful for both in vivo and in vitro biomedical research and applications. Therefore, this work aimed to isolate fungal strains from Taif soil samples, which have the ability to synthesize silver nanoparticles. The fungus Trichoderma harzianum, when challenged with silver nitrate solution, accumulated silver nanoparticles (AgNBs) on the surface of its cell wall in 72 h. These nanoparticles, dislodged by ultrasonication, showed an absorption peak at 420 nm in a UV-visible spectrum, corresponding to the plasmon resonance of silver nanoparticles. The transmission electron micrographs of dislodged nanoparticles in aqueous solution showed the production of reasonably monodisperse silver nanoparticles (average particle size: 4.66 nm) by the fungus. The percentage of non hatching eggs treated with the Triclabendazole drug was 69.67%, while this percentage increased to 89.67% in combination with drug and AgNPs.

1 March 2010 in Foodborne Pathogens and Disease
Verified
Journal Article
Closed access
AAAbdullah D. Altalhi
Abdullah D. Altalhi
YGYoussuf Gherbawy
Youssuf Gherbawy
SHSabry Hassan
Sabry Hassan
The present study was carried out to screen and analyze the genetic characteristics of antibiotic resistance in Escherichia coli strains isolated from chicken meat marketed in the local markets of the Taif region in Saudi Arabia. A total of 119 samples were purchased from various supermarkets and examined for bacterial contamination with resistant E. coli. Thirty-seven E. coli isolates were evaluated for their antibiotic susceptibilities and the presence of class 1 integrons and antibiotic resistance genes. Results of antibiograms revealed that E. coli isolates were resistant to one or more of the antibiotics tested. Resistance was most frequently observed against sulphafurazole (89.2%), ampicillin (78.4%), nalidixic acid (70.3%), streptomycin (48.6%), chloramphenicol (32.4%), and gentamicin (24.3%). Fifteen E. coli strains have multidrug resistance phenotypes and harbored at least three antibiotic resistance genes. The blaTEM (β-lactamase) and sul (sulfonamide) resistance encoding genes were detected in all the tested isolates. Polymerase chain reaction screening detected class 1 integrons in all multiresistant E. coli isolates. The present study provides an assessment of the occurrence of multidrug resistance of E. coli from raw chicken meat collected from local markets.