S. M. A. Abdelmalek and Y.R. Badran, " 1. Pseudomonas aeruginosa PAO1 Adapted to 2-Phenoxyethanol shows cross resistance to dissimilar biocides and increased susceptibility to antibiotics. " , "Folia Microbiologica ",Vol.55,No.6, Springer, , 12/01/2010
ABSTRACT. The growth adaptability to increasing concentration of the biocide 2-phenoxyethanol (PE)
was determined in Pseudomonas aeruginosa PAO1 (P.a.) as part of efforts to understand and control the biocide
tolerance and its effect on cross-resistance to other biocides and resistance to antibiotics. After repeated
subculturing in media containing increasing sub-minimum-inhibitory PE concentration, P.a. exhibited an
adaptive resistance indicated by two-fold increase in MIC at the 10th passage. The resistance was stable and
remained after passaging the strain in further 7 successive passages in PE-free growth media. The strain
showed cross-resistance towards dissimilar biocides and displayed increased susceptibility to antibiotics,
which was not influenced by the presence of the efflux inhibitor ‘carbonyl cyanide m-chlorophenyl hydrazone’.
Outer membranes of adapted strain showed altered protein profile when examined by SDS-PAGE.
S. M. A. Abdel Malek, I.S.I. Al-Adham, K.Z. Matalka and P.J. Collier , " 2. Resistance of Pseudomonas aeruginosa PAO1 to Zinc pyrithione involves an efflux system " , "Current Microbiology",Vol.59 ,No.2, Springer, , 01/01/2009
Abstract The aim of this study is to investigate the
involvement of an efflux pump in the development of
Pseudomonas aeruginosa resistance to zinc pyrithione
(ZnPT). In the presence of efflux inhibitor carbonyl cyanide
m-chlorophenyl-hydrazone (CCCP), the minimum inhibitory
concentration of ZnPT for P. aeruginosa resistant cells
is reduced significantly (p\0.05). In addition, the concentration
of ZnPT excluded by the resistant bacteria was
reduced significantly (p\0.01). However, the above
reductions did not reach the levels measured for P. aeruginosa
PAO1 sensitive strain. Furthermore, such changes in
P. aeruginosa resistant cells were correlated with the overexpression
of outer membrane proteins, reduced sensitivity
toward imipenem (p\0.01) and increased sensitivity
toward sulphatriad and chloramphenicol (p\0.05). In a
continuation to a previous study, we conclude that P.
aeruginosa resistance to ZnPT is multifactorial and involves
induced efflux systems.
Maysa Al-Hanbali, Dalia Ali, Mona Bustami. Suzan Abdel-Malek, Rami Al-Hanbali, Tawfiq Al-Hussieni, Fadi Qadan, Khalid Matalka, " 3. Epicatechin suppresses IL-6, IL-8 and enhances IL-10 production with NF-ҝB nuclear translocation in whole blood stimulated system " , "Neuroendocrinology Letters ",Vol.30,No.1, , , 01/01/2009
S. M. A. Abdel Malek, I.S.I. Al-Adham, C.L. Winder, R.E.J. Bunltjens, K.M.A. Gartland and P.J. Collier ., " 5. Antimicrobial susceptibility changes and T-OMP shifts in pyrithione passaged planktonic cultures of Pseudomones aeruginosa PAOI. " , "Journal of Applied Microbiology ",Vol.92,No., , , 01/01/2002
C.L. Winder, I. S. I. Al-Adham, S. M. A. Abdel Malek, T. E. J. Buultjens, A. J. Horrocks and P. J. Collier. , " 6. Outermembrane Protein shifts in Biocide – resistant Pseudomonas aeruginosa PAOl " , "Journal of Applied Microbiology ",Vol.89,No.2, , , 01/01/2001
Khalid S. Matalka, Ahmed Sidki, Suzan M. Abdel- Malek, Abdul – Jalil Thewani. , " 7. Academic stress – Influence on Epstein Barr virus and Cytomegalovirus reactivation, cortisol and prolactin. " , "",Vol.,No., , , 01/01/1998
R. Alkaramany, J. Kazar, S. A. Malek, S. Al Mufti and M. Badria. , " 8. Rapid quantitative assay of Rabies Post – vaccination- Antibody by ELISA " , "AMPIS",Vol.3,No., , , 01/01/1988
. A.K. Al-Ghamdi, S. M. A. Abdelmalek, M.S. Bamaga, E.I. Azhar, M.H Waked and Z. Alsaied. , " Bacterial contamination of Saudi "One" riyal paper ntoes " , "Southeast Asian Journal of Tropical Medicine and Public Health ",Vol.42 ,No.3, , , 05/01/2011
Fomits are inanimate objects that are capable of absorbing, harboring and transmitting infectious microorganisms. Paper currency, an exchangeable fomit is constantly subjected to contamination through droplets from coughing, touching of hands and placement on dirty surfaces. Exposing the true facade of the possible paper currency-contamination would help in increasing public health awareness when it comes to day-to-day activities. This study aims at investigating the quality of bacterial contamination on the Saudi one riyal paper note. Two hundred one riyal bills (100 of the 4th version and 100 of the 5th version) were collected from general population in the city of Jeddah to survey bacterial contamination. The currencies were processed for bacterial isolation using blood agar and MacConkey agar. Investigation revealed that 88% of the total samples collected were contaminated with mixed (two types or more) bacterial growth. The entire 4th version samples showed mixed bacterial growth of the following species in descending order of percentage; (79%) Gram-positive bacilli, (75%) coagulase-negative staphylococci, (38%) Staphylococcus aureus, (21%) Klebsiella spp., (19%) Pseudomonas spp., (9%) Escherichia coli, (8%) Viridans group streptococci (VGS), and (4%) non-hemolytic streptococci. Comparatively newer 5th version bills showed 76% of mixed bacterial growth in the following order of percentage; (68%) Gram-positive bacilli, (64%) coagulase-negative staphylococci, (13%) S. aureus, (9%) Klebsiella spp., (5%) Pseudomonas spp., (2%) E. coli and (2%) VGS. Results indicate that Saudi one riyal paper currency is commonly contaminated with bacteria, and might act as an environmental vehicle for the transmission of potentially pathogenic bacteria. It was clear that the more the bill had been handled the more intense the contamination was.
A. K. Al-Ghamdi. S. M. A. Abdelmalek, A. M. Ashshi, H. Faidah, H. Shukri and A. A. Jiman-Fatani., " Bacterial contamination of computer keyboards and mice, elevator button and shopping carts " , "African Journal of Microbiology Research",Vol.5,No.23, academic journals, , 10/23/2011
This study aims at investigating the status of bacterial contamination of four daily used objects, computer keyboards, computer mice, elevator knobs and shopping carts handles. A total of 400 samples were collected from 4 different objects; 100 from each. Samples were collected from different places (offices, internet cafes, homes, buildings and supermarkets) in the city of Jeddah, Saudi Arabia. 95.5% of the total samples collected were contaminated with mixed bacterial growth. Coagulase-negative staphylococci dominated the isolates. The second most common bacterial growth in all specimens was Gram-positive bacilli. Potential pathogens isolated from all specimens were: Staphylococcus aureus, Pseudomonas spp. and Gram negative bacilli. Results indicate that Internet café computer keyboards and mice showed 100% contamination in comparison with other objects. The presence of pathogenic and commensal bacteria on the four objects indicates that they might act as environmental vehicles for the transmission of potentially pathogenic bacteria.
S. M. A. Abdelmalek, S. Zeidan and Y .R. Badran. , " The retrieval of Antibiotic Sensitivity by 2-PE adapted-MDR clinical isolate of Pseudomonas aeruginosa. " , "African Journal of Microbiology Research",Vol.7,No.25, academicjournals, , 06/18/2013
2-Phenoxyethanol (2-PE) is a biocide used as a preservative in pharmaceutical, cosmetic and perfumery
formulations. It is known for its rapid bactericidal effect against a wide range of bacteria. In the present
study, clinical samples of multi drug resistant (MDR) Pseudomonas aeruginosa and Escherichia coli
were grown in an increasing sub-minimal inhibitory concentration of 2-PE to observe if adaptation
could be obtained and consequently retrieval of antibiotic susceptibility to clinically used antibiotics.
Minimal inhibitory concentration (MIC) of 2-PE was determined for both MDR E. coli and P.
aeruginosa. Adaptation to the biocide was attempted by repeated sub- culturing of the isolates in
increasing sub-minimal-inhibitory concentration of the biocide. E. coli was able to grow in the presence
of sub-MIC of 2-PE for two passages only and a slight rise in MIC was observed. MDR P. aeruginosa
rapidly obtained an adaptive resistance towards the biocide with an increase in MIC from 5.4 to 13.7g%.
Antibiotic sensitivities for both, MDR and MDR-2-PE adapted E. coli and P. aeruginosa were detected.
MDR2-PE resistant P. aeruginosa showed significant improvement in antibiotic sensitivity while no
change was observed with E. coli. Our results suggest an intriguing species specific link between
biocide resistance and changes in antibiotic susceptibilities, findings that could be utilized in
controlling the spread of antibiotic resistance and ambitiously improving the activity of some existing
Background: Psidium guajava (guava) leaf extracts have been extensively studied for their anti-microbial effect. Yet, very few studies investigated the antimicrobial effect of the ripe guava fruit. Aim: This study aims at examining aqueous extracts of ripe Psidium guajava fruit, bulb, seeds and peel
Background/objective: The use of antibiotics in the treatment of acne has been debatable especially when the abuse of antibiotics is strongly linked to emerging antibiotic resistant strains of bacteria. The aim of this study is to assess dermatologists’ knowledge about antimicrobial drug resistance
Valspodar (PSC833) a mammalian efflux pump inhibitor improves susceptibility of MRSA to antibiotics.