Atef Diab - Academia.edu (original) (raw)
Papers by Atef Diab
Journal of Taibah University Medical Sciences, 2009
Objective Investigation of the presence and distribution pattern of plasmid-linked antibiotic res... more Objective Investigation of the presence and distribution pattern of plasmid-linked antibiotic resistance amongst Gram-negative bacterial strains recovered from wastewater of hospitals and haemodialysis units. Drawing up a physical map of the most frequently distributed plasmids. Methods Representatives G-ve bacterial strains; 59 isolates, were chosen from a previous study for the same authors, as of the most resistant ones (resist more than 3 up to 9 antibiotics to > 100 μg/ml.). Miniprep protocol and gel electrophoresis technique were adopted for the detection and isolation of ccc plasmid DNA from the differentially-isolated G-ve bacteria. Restriction analysis using 11 DNA restriction enzymes and "Plasp" computer program against λ phage DNA digested with Hind III, for physical mapping of the most distributed plasmid. Results Results revealed the presence of seven different plasmids, distributed as 1-3 different types of plasmids in 68% (40/59) of the strains; chosen as representatives of the most resistant ones (resist more than 3 up to 9 antibiotics to > 100 μg/ml.). The detected plasmid sizes were estimated against HindIII-digested λ phage and found ranged from 36,844 to 2,027 bp. Preliminary physical mapping was constructed for the plasmid (23130 bp) that was the most distributed amongst more than 90% of the plasmid-bearing strains and was the only found singly. Conclusion The isolated, characterized and the mapped plasmid (s), suggest the possibility of high rate of both vertical and horizontal distribution of these plasmids amongst the isolated Gve bacterial Genera and species.
Egyptian Journal of Microbiology, Jun 1, 2020
estimated as deaths. In intensive care units (ICUs), Gram-negative pathogens are responsible for ... more estimated as deaths. In intensive care units (ICUs), Gram-negative pathogens are responsible for the majority of these deadly infections. Multidrug resistance (MDR) in the seorganisms has been attributed to production of modified enzymes responsible of elevated MICs and MBC/MICs putting them in the transient stages for persistence and tolerance. Bacterial cells those can survive high doses of antibiotics comprise a subpopulation of persistent but not resistant cells.Bacterial isolates (326) were collected from nosocomial infections via microbiology laboratories of police hospitals in Cairo. Frequency-wise, it was found that Escherichia is the most frequent (155), Pseudomonas (96), Staphylococcus (34), Klebsiella (24), Proteus (16) while Citrobacter is the least frequent (1). Pseudomonas, Klebsiella, Proteus and Citrobacter showed the highest MDRs, with the highest MICs in a descending order. Results clearly indicated the high risk of the two Pseudomonas aeruginosa from sputum and urine persisting (inhibited but not killed) against MICs 3 tested antibiotics; CRO, AMC and FEB. It is highly recommended here to run tests for MBC/MICs to choose the antibiotic with least MBC/MIC ratio; less than four, in order to reduce the transient persistent and/ or tolerant stages.
Journal of Taibah University Medical Sciences, 2009
Objective Investigation of the presence and distribution pattern of plasmid-linked antibiotic res... more Objective Investigation of the presence and distribution pattern of plasmid-linked antibiotic resistance amongst Gram-negative bacterial strains recovered from wastewater of hospitals and haemodialysis units. Drawing up a physical map of the most frequently distributed plasmids. Methods Representatives G-ve bacterial strains; 59 isolates, were chosen from a previous study for the same authors, as of the most resistant ones (resist more than 3 up to 9 antibiotics to > 100 μg/ml.). Miniprep protocol and gel electrophoresis technique were adopted for the detection and isolation of ccc plasmid DNA from the differentially-isolated G-ve bacteria. Restriction analysis using 11 DNA restriction enzymes and "Plasp" computer program against λ phage DNA digested with Hind III, for physical mapping of the most distributed plasmid. Results Results revealed the presence of seven different plasmids, distributed as 1-3 different types of plasmids in 68% (40/59) of the strains; chosen as representatives of the most resistant ones (resist more than 3 up to 9 antibiotics to > 100 μg/ml.). The detected plasmid sizes were estimated against HindIII-digested λ phage and found ranged from 36,844 to 2,027 bp. Preliminary physical mapping was constructed for the plasmid (23130 bp) that was the most distributed amongst more than 90% of the plasmid-bearing strains and was the only found singly. Conclusion The isolated, characterized and the mapped plasmid (s), suggest the possibility of high rate of both vertical and horizontal distribution of these plasmids amongst the isolated Gve bacterial Genera and species.
Qualitative and quantitative bacteriological analysis of the dialysate-water exhaust for the only... more Qualitative and quantitative bacteriological analysis of the dialysate-water exhaust for the only two haemodialysis units found at Al-Madinah Al-Mounwwarah, were studied. Ten samples were collected over 75 days, 5 times from each site of sampling on biweekly basis. Enumeration of total viable (TVB) and total coliform (TC) bacterial counts CFU/ ml, showed figures ranged from 0.0 to 5231x10 2 CFU /ml and from 0.0 to 73x10 2 CFU /ml, respectively. Specific identification of the isolated bacterial strains using API 20 E strips confirmed that isolated bacterial populations composed of 6 genera in one unit and 7 in the other. Bacterial diversity was relatively poor, but the counts were obviously-high.Determination of MIC (s) , MBC (s) ,as well as, the MIC/MBC indexes for 153 representative strains of the bacterial population isolated in the study were done. All the studied strains exhibited resistance to at least 3, out of the 9 tested antibiotics up to MIC (S) > 100 μg/ml.
Biosciences, Biotechnology Research Asia, Jun 30, 2012
The present work surveyed Haemodialysis (HD) units, in order to assess the bacteriological and to... more The present work surveyed Haemodialysis (HD) units, in order to assess the bacteriological and toxicological qualities of dialysis water and dialysate. Also determine experimentally to how extent the bacterial activities are involved in immune depression for the patients. The most commonly isolated Gram-negative bacteria from treated water were Aeromonas spp. (22.2%). Endotoxin concentrations ranged between 3-113 (EU/mL) for water and dialysate respectively. The haematological analysis had non significant except haemoglobin level had a significant values (p = 0.02). The clinical data showed comparable difference than control patients. Missing, out of work, bypassed and even erroneously arranged treatment facilities are some of the reasons responsible for the detected high levels of bacterial and endotoxin in final product water. The presence and growth of bacteria in water and dialysate should be controlled and the endotoxin testing must be a part of the regular quality control regime, to minimize the risk of adverse reactions in HD patients.
Malaysian Journal of Microbiology, Jun 1, 2012
The study focused on finding if there is any possible relation between the intestinal bacterial p... more The study focused on finding if there is any possible relation between the intestinal bacterial population quantitative and qualitative and the deficiency of the most important iron compounds as haem precursors. Methodology and Results: Blood complete picture and stool analyses were done to 750 volunteer cases whom were asked for these analyses by their physicians. Analyses proved that 560 cases representing 75.2 % were anemic as the RBC(s) based on counts of the total studied cases of less than 263 x 10 4 and the haemoglobin amount ranged between 7.2 and 11.3 g/dl, while the remainder 24.8 % of the volunteer sample was not anemic. A high male/female ratio of anemic cases, 1:27 was also documented. Considering that all the studied stool samples should be completely free from any parasites or any other anemia-related diseases was a priority. Bacteriological analysis of stool samples of the anemic cases resulted in the detection of high counts of total viable bacteria, exceeded 42 x 10 9 cfu/g, while it was never more than 26 x 10 6 cfu/g and decreased to 4 x 10 6 cfu/g in many cases in this study. Identifying of the 361 bacterial isolates, were found to belong to 12 genera and 19 species, 6 of them; Pseudomonas putrefaciens, Micrococcus luteus, Erysipelothrix rhusiopathiae, Bacillus megaterium, Bacillus pumilus and Bacillus coagulans , were found and in high counts in the stool samples of only anemic cases. The ability of these isolates to compete for iron compounds such as ferrous fumarate alone or with glucose and phytate as activators or inhibitors to these abilities was investigated. Results proved 11 species out of the 19 identified species are capable to use and compete on ferrous fumarate as a haem precursor. Sensitivity test for the representatives of the 19 species and 6 of the most commonly used antibiotics in the Egyptian pharmacy, using standard disc method, revealed variable susceptibilities of almost all of them to more than one of the studied antibiotics, except Corynebacterium equatium, which was found very resistant to two antibiotics; colistin sulfate and erythrocin. Conclusion, significance and impact of study: The study finally concluded the strong role of intestinal bacterial counts and types as competitors on the haem precursor iron-containing compounds like ferrous fumarate.
Journal of Biological Sciences, May 15, 2002
Journal of International Environmental Application and Science, Apr 1, 2009
The principle drinking water sources at the Kingdom of Saudi Arabia (KSA), including Al-Madinah A... more The principle drinking water sources at the Kingdom of Saudi Arabia (KSA), including Al-Madinah Al-Mounwwarah are the desalinated and underground well water. The present study focused on evaluating this drinking water sources portability from the bacteriological point of view. Searching for any possible correlation between bacteria present in the studied drinking water and those which have been isolated from the final effluent waste water of hospitals, is a crucial target. Water samples were collected from underground well water, underground reservoirs and taps at the nearest neighbourhood to previously-studied five hospitals namely; King Fahd, Ohod, Al-Mouassat, Women and Maternity and Saudi-German. Water samples from two additional sites namely; Al-Eskan and Al-Bsateen, away from these hospitals were investigated as control remote areas. Drinking bottled water (6 trade marks) processed at Al-Madinah Al-Mounwwarah namely; Doraq, Nada, Quba, Sarat, Taibah and Watanya, were also studied. Qualitative and quantitative bacteriological full analyses for water samples collected from the 27 sites, including enumeration of total viable (TVB), total coliform (TC) and faecal coliform (FC) bacteria in addition to the identification of the purified isolates to the specific level using API 20E strips and its software program, have been accomplished. Antibiotic-resistance profiles, expressed in MIC µg/ml, of the most important Gram-ve rods against 9 antibiotics namely; bacitracin, chloramephincol, erythromycin, impenim, penicillin G, rifampicin, streptomycin, tetracycline and vancomycin, were also drown up. Screaning for plasmids in the antibiotic-resistant isolates was fully studied. Results showed high and fluctuated TVB, TC and FC bacterial counts ranged between 100 : 1000, 90 : 800 and 1 : 3 cfu/100 ml, respectively, in the studied underground well water, indicating its unacceptable quality for drinking. Underground reservoirs and tap water samples were free from TC and FC, giving acceptable drinking water according to both the local and international standards, although having low to moderate TVB counts (1 : 15 cfu/ 100 ml). No direct correlation between the bacterial counts and the neiborhood hospitals, compared with counts detected in water samples from the two remote control areas. The study clearly-assured the bacteriologically-high grade quality of all the six investigated bottled water, showing no counts for TC and/or FC, so safe to drink. The low TVB counts (3 : 24 cfu/ 100 ml) seemed, numerically-potable according to standards, but health threatens are alarming because of the ability of some of these commensals to accept extrachromosomal elements changing their characteristics and impose pathogenic behaviours. Identification revealed that 74% were Gram-ve, 56% of it are rods, while 18% are cocci, only 26% were Gram +ve rods, 19% are spore-formers and 7% are non spore-formers, while no Gram +ve cocci were detected. Gram-ve rods belonged to 8 strains, 7 species and 7 genera namely; Escherichia coli 1, Citrobacter frundii, Providencia stuartii, Proteus vulgaris, Cryseomonas leteula , Stenotrophomonas maltophili (which have been heavily-isolated from almost all the studied bottled water but non of the other sources), Aeromonas hydrophila (group 1&2). The most distributed species were Aeromonas hydrophila (group 1), Cryseomonas leteula and Stenotrophomonas maltophilia. All of the 8 studied strains resist from 3 : 9 of the antibiotics at MIC(s) from 50 :100 µg/ml. Molecular studies resulted in the detection of plasmids in 5 out of the 8 strains. Miniprep, alkaline lysis and 1% agarose gel protocols, along with electrophoresis against Hind III partially-digested Lambda phage, showed only one plasmid in each, all of the same size; 23130 bp. It is very important here to record that only 3 isolates namely; Escherichia coli 1, Provedencia stuartii and Stenotrophomonas maltophilia , out of 5 isolates of these were identical; from the points of antibiotic-resistance profiles, MIC(s) and plasmid content, with 3 of those isolated from hospitals waste water in the previous study.
European Chemical Bulletin, 2018
Qualitative and quantitative bacteriological analysis of the dialysate-water exhaust for the only... more Qualitative and quantitative bacteriological analysis of the dialysate-water exhaust for the only two haemodialysis units found at Al-Madinah Al-Mounwwarah, were studied. Ten samples were collected over 75 days, 5 times from each site of sampling on biweekly basis. Enumeration of total viable (TVB) and total coliform (TC) bacterial counts CFU/ ml, showed figures ranged from 0.0 to 5231x10 2 CFU /ml and from 0.0 to 73x10 2 CFU /ml, respectively. Specific identification of the isolated bacterial strains using API 20 E strips confirmed that isolated bacterial populations composed of 6 genera in one unit and 7 in the other. Bacterial diversity was relatively poor, but the counts were obviously-high.Determination of MIC(s), MBC(s) ,as well as, the MIC/MBC indexes for 153 representative strains of the bacterial population isolated in the study were done. All the studied strains exhibited resistance to at least 3, out of the 9 tested antibiotics up to MIC(S) > 100 μg/ml. [Atef M. Diab a...
Applied Biochemistry and Biotechnology, 2021
The cleaning activity of surface-active agents such as rhamnolipids (RLs) requires utmost effecti... more The cleaning activity of surface-active agents such as rhamnolipids (RLs) requires utmost effectiveness and is employed abundantly in various industries, particularly laundry cleaning, detergents, and cosmetics. In the current study, RLs were produced from Pseudomonas aeruginosa isolated from oil-contaminated soil using a minimal medium amended with agro-industrial by-products of refinery vegetable oil wastes (comprising of unsaturated types of fatty acids as determined by GC analysis) and dairy whey. The results showed that an amount of 5.72 g/L of RLs were obtained, while lower concentrations were obtained using chemically defined carbon sources. Ten congeners of mono- and di-RLs were detected by LC-MS, and they reduced the surface tension of water to 26 mN/m with a critical micelle concentration of 33 mg/L. Furthermore, the produced RLs showed promising cleaning and detergency properties in the removal of different stains on tested fabrics with a Stain Removal Index (SRI) of 17.45%. Moreover, an efficient cleaning was obtained when RLs were applied to a liquid detergent formulation model, and a cleaning power (∆E) of 245.95 and SRI of 36.28% were achieved. The present work showed that the produced RLs could be exploited as a powerful and alternative eco-friendly cleaning agent in many industries.
European Chemical Bulletin, 2018
Multiplex PCR for the detection of AmpC genes has proved useful as a rapid screening tool to dist... more Multiplex PCR for the detection of AmpC genes has proved useful as a rapid screening tool to distinguish cefoxitin resistant non-AmpC producers from cefoxitin resistant AmpC producers. In addition to AmpC gene detection, the data generated from the multiplex PCR method can distinguish which family of AmpC gene is present in the resistant organism thereby distinguishing possible inducible AmpC producers from non-inducible producers of AmpC. The present study was designed to evaluate these issues among cephalosporin-resistant isolates of Klebsiella spp. and to assess the performance characteristics of phenotypic tests, using different inhibitors, compared to the PCR, for their rapid and accurate detection. Fifty eight out of 100 isolates were AmpC producers by PCR. Fifty six out of 58 isolates that were positive by PCR test were resistant to FOX. Thirty out of 58 AmpC producers were ESBL positive by E-test and MDDST in detection of ESBL in the presence of AmpC. While 23 /58 were positive by DDST for detection of ESBL in presence of Amp. This study reveals high prevalence of pAmpC and ESBL enzymes among bacterial isolates from our hospital. ESBL production may mask the phenotypic detection of pAmpC enzymes. Modified 3 dimensional(M3D) is a simple and reliable method for detection of pAmpCs. MDDST serve as reliable confirmatory tests for detection of ESBLs in AmpC-positive isolates.
Egyptian Journal of Microbiology, 2020
T HE INTEREST in natural antimicrobial preservatives is rapidly grown due to their exceptional pr... more T HE INTEREST in natural antimicrobial preservatives is rapidly grown due to their exceptional properties such as biodegradability, biocompatibility, and lower toxicity. On the contrary, common synthesized preservatives are more toxic, partially or non-degradable, and have undesirable side effects on human health and the environment. Furthermore, the resistance of microorganisms to current antimicrobial preservatives is increasing. In the present study, rhamnolipid was produced from Pseudomonas aeruginosa ATCC 9027, and twelve congeners of rhamnolipids were elucidated by ESI-MS. Additionally, rhamnolipids reduced the surface tension of water to 26mN/m with a critical micelle concentration value of 22mg/L. The produced rhamnolipids showed prominent lower toxicity against the brine shrimp Artemia salina than those of positive control and methylisothiazolinone. A significantant antimicrobial effect of rhamnolipids was achieved in vitro, whereas the disc diffusion assay showed noticeable inhibition zones around the paper discs saturated with different concentrations of the rhamnolipid produced in this study, with MICs ranged between 8 and 336μg/ml against Escherichia coli, Salmonella typhimurium, Pseudomonas aeruginosa, Staphylococcus aureus, Bacillus subtilis, Saccharomyces cerevisiae, Candida albicans and Aspergillus brasiliensis. Moreover, a promising preservation efficacy of the produced rhamnolipid was obtained when applied to a personal care formulation model even after 28 days of incubation, with reduction values of about 3 and 1 expressed in log units for bacteria and fungi, respectively. However, rhamnolipids could be recommended as a powerful nontoxic bio-preservative for personal care formulations.
Egyptian Journal of Microbiology, 2020
estimated as deaths. In intensive care units (ICUs), Gram-negative pathogens are responsible for ... more estimated as deaths. In intensive care units (ICUs), Gram-negative pathogens are responsible for the majority of these deadly infections. Multidrug resistance (MDR) in the seorganisms has been attributed to production of modified enzymes responsible of elevated MICs and MBC/MICs putting them in the transient stages for persistence and tolerance. Bacterial cells those can survive high doses of antibiotics comprise a subpopulation of persistent but not resistant cells.Bacterial isolates (326) were collected from nosocomial infections via microbiology laboratories of police hospitals in Cairo. Frequency-wise, it was found that Escherichia is the most frequent (155), Pseudomonas (96), Staphylococcus (34), Klebsiella (24), Proteus (16) while Citrobacter is the least frequent (1). Pseudomonas, Klebsiella, Proteus and Citrobacter showed the highest MDRs, with the highest MICs in a descending order. Results clearly indicated the high risk of the two Pseudomonas aeruginosa from sputum and urine persisting (inhibited but not killed) against MICs 3 tested antibiotics; CRO, AMC and FEB. It is highly recommended here to run tests for MBC/MICs to choose the antibiotic with least MBC/MIC ratio; less than four, in order to reduce the transient persistent and/ or tolerant stages.
Malaysian Journal of Microbiology, 2012
The study focused on finding if there is any possible relation between the intestinal bacterial p... more The study focused on finding if there is any possible relation between the intestinal bacterial population quantitative and qualitative and the deficiency of the most important iron compounds as haem precursors. Methodology and Results: Blood complete picture and stool analyses were done to 750 volunteer cases whom were asked for these analyses by their physicians. Analyses proved that 560 cases representing 75.2 % were anemic as the RBC(s) based on counts of the total studied cases of less than 263 x 10 4 and the haemoglobin amount ranged between 7.2 and 11.3 g/dl, while the remainder 24.8 % of the volunteer sample was not anemic. A high male/female ratio of anemic cases, 1:27 was also documented. Considering that all the studied stool samples should be completely free from any parasites or any other anemia-related diseases was a priority. Bacteriological analysis of stool samples of the anemic cases resulted in the detection of high counts of total viable bacteria, exceeded 42 x 10 9 cfu/g, while it was never more than 26 x 10 6 cfu/g and decreased to 4 x 10 6 cfu/g in many cases in this study. Identifying of the 361 bacterial isolates, were found to belong to 12 genera and 19 species, 6 of them; Pseudomonas putrefaciens, Micrococcus luteus, Erysipelothrix rhusiopathiae, Bacillus megaterium, Bacillus pumilus and Bacillus coagulans , were found and in high counts in the stool samples of only anemic cases. The ability of these isolates to compete for iron compounds such as ferrous fumarate alone or with glucose and phytate as activators or inhibitors to these abilities was investigated. Results proved 11 species out of the 19 identified species are capable to use and compete on ferrous fumarate as a haem precursor. Sensitivity test for the representatives of the 19 species and 6 of the most commonly used antibiotics in the Egyptian pharmacy, using standard disc method, revealed variable susceptibilities of almost all of them to more than one of the studied antibiotics, except Corynebacterium equatium, which was found very resistant to two antibiotics; colistin sulfate and erythrocin. Conclusion, significance and impact of study: The study finally concluded the strong role of intestinal bacterial counts and types as competitors on the haem precursor iron-containing compounds like ferrous fumarate.
Egyptian Journal of Biology, Jul 13, 2004
Egyptian Journal of Biology Vol.3 2001: 59-6
Pakistan Journal of Biological Sciences, 2014
Journal of Taibah University Medical Sciences, 2009
Objective Investigation of the presence and distribution pattern of plasmid-linked antibiotic res... more Objective Investigation of the presence and distribution pattern of plasmid-linked antibiotic resistance amongst Gram-negative bacterial strains recovered from wastewater of hospitals and haemodialysis units. Drawing up a physical map of the most frequently distributed plasmids. Methods Representatives G-ve bacterial strains; 59 isolates, were chosen from a previous study for the same authors, as of the most resistant ones (resist more than 3 up to 9 antibiotics to > 100 μg/ml.). Miniprep protocol and gel electrophoresis technique were adopted for the detection and isolation of ccc plasmid DNA from the differentially-isolated G-ve bacteria. Restriction analysis using 11 DNA restriction enzymes and "Plasp" computer program against λ phage DNA digested with Hind III, for physical mapping of the most distributed plasmid. Results Results revealed the presence of seven different plasmids, distributed as 1-3 different types of plasmids in 68% (40/59) of the strains; chosen as representatives of the most resistant ones (resist more than 3 up to 9 antibiotics to > 100 μg/ml.). The detected plasmid sizes were estimated against HindIII-digested λ phage and found ranged from 36,844 to 2,027 bp. Preliminary physical mapping was constructed for the plasmid (23130 bp) that was the most distributed amongst more than 90% of the plasmid-bearing strains and was the only found singly. Conclusion The isolated, characterized and the mapped plasmid (s), suggest the possibility of high rate of both vertical and horizontal distribution of these plasmids amongst the isolated Gve bacterial Genera and species.
Egyptian Journal of Microbiology, Jun 1, 2020
estimated as deaths. In intensive care units (ICUs), Gram-negative pathogens are responsible for ... more estimated as deaths. In intensive care units (ICUs), Gram-negative pathogens are responsible for the majority of these deadly infections. Multidrug resistance (MDR) in the seorganisms has been attributed to production of modified enzymes responsible of elevated MICs and MBC/MICs putting them in the transient stages for persistence and tolerance. Bacterial cells those can survive high doses of antibiotics comprise a subpopulation of persistent but not resistant cells.Bacterial isolates (326) were collected from nosocomial infections via microbiology laboratories of police hospitals in Cairo. Frequency-wise, it was found that Escherichia is the most frequent (155), Pseudomonas (96), Staphylococcus (34), Klebsiella (24), Proteus (16) while Citrobacter is the least frequent (1). Pseudomonas, Klebsiella, Proteus and Citrobacter showed the highest MDRs, with the highest MICs in a descending order. Results clearly indicated the high risk of the two Pseudomonas aeruginosa from sputum and urine persisting (inhibited but not killed) against MICs 3 tested antibiotics; CRO, AMC and FEB. It is highly recommended here to run tests for MBC/MICs to choose the antibiotic with least MBC/MIC ratio; less than four, in order to reduce the transient persistent and/ or tolerant stages.
Journal of Taibah University Medical Sciences, 2009
Objective Investigation of the presence and distribution pattern of plasmid-linked antibiotic res... more Objective Investigation of the presence and distribution pattern of plasmid-linked antibiotic resistance amongst Gram-negative bacterial strains recovered from wastewater of hospitals and haemodialysis units. Drawing up a physical map of the most frequently distributed plasmids. Methods Representatives G-ve bacterial strains; 59 isolates, were chosen from a previous study for the same authors, as of the most resistant ones (resist more than 3 up to 9 antibiotics to > 100 μg/ml.). Miniprep protocol and gel electrophoresis technique were adopted for the detection and isolation of ccc plasmid DNA from the differentially-isolated G-ve bacteria. Restriction analysis using 11 DNA restriction enzymes and "Plasp" computer program against λ phage DNA digested with Hind III, for physical mapping of the most distributed plasmid. Results Results revealed the presence of seven different plasmids, distributed as 1-3 different types of plasmids in 68% (40/59) of the strains; chosen as representatives of the most resistant ones (resist more than 3 up to 9 antibiotics to > 100 μg/ml.). The detected plasmid sizes were estimated against HindIII-digested λ phage and found ranged from 36,844 to 2,027 bp. Preliminary physical mapping was constructed for the plasmid (23130 bp) that was the most distributed amongst more than 90% of the plasmid-bearing strains and was the only found singly. Conclusion The isolated, characterized and the mapped plasmid (s), suggest the possibility of high rate of both vertical and horizontal distribution of these plasmids amongst the isolated Gve bacterial Genera and species.
Qualitative and quantitative bacteriological analysis of the dialysate-water exhaust for the only... more Qualitative and quantitative bacteriological analysis of the dialysate-water exhaust for the only two haemodialysis units found at Al-Madinah Al-Mounwwarah, were studied. Ten samples were collected over 75 days, 5 times from each site of sampling on biweekly basis. Enumeration of total viable (TVB) and total coliform (TC) bacterial counts CFU/ ml, showed figures ranged from 0.0 to 5231x10 2 CFU /ml and from 0.0 to 73x10 2 CFU /ml, respectively. Specific identification of the isolated bacterial strains using API 20 E strips confirmed that isolated bacterial populations composed of 6 genera in one unit and 7 in the other. Bacterial diversity was relatively poor, but the counts were obviously-high.Determination of MIC (s) , MBC (s) ,as well as, the MIC/MBC indexes for 153 representative strains of the bacterial population isolated in the study were done. All the studied strains exhibited resistance to at least 3, out of the 9 tested antibiotics up to MIC (S) > 100 μg/ml.
Biosciences, Biotechnology Research Asia, Jun 30, 2012
The present work surveyed Haemodialysis (HD) units, in order to assess the bacteriological and to... more The present work surveyed Haemodialysis (HD) units, in order to assess the bacteriological and toxicological qualities of dialysis water and dialysate. Also determine experimentally to how extent the bacterial activities are involved in immune depression for the patients. The most commonly isolated Gram-negative bacteria from treated water were Aeromonas spp. (22.2%). Endotoxin concentrations ranged between 3-113 (EU/mL) for water and dialysate respectively. The haematological analysis had non significant except haemoglobin level had a significant values (p = 0.02). The clinical data showed comparable difference than control patients. Missing, out of work, bypassed and even erroneously arranged treatment facilities are some of the reasons responsible for the detected high levels of bacterial and endotoxin in final product water. The presence and growth of bacteria in water and dialysate should be controlled and the endotoxin testing must be a part of the regular quality control regime, to minimize the risk of adverse reactions in HD patients.
Malaysian Journal of Microbiology, Jun 1, 2012
The study focused on finding if there is any possible relation between the intestinal bacterial p... more The study focused on finding if there is any possible relation between the intestinal bacterial population quantitative and qualitative and the deficiency of the most important iron compounds as haem precursors. Methodology and Results: Blood complete picture and stool analyses were done to 750 volunteer cases whom were asked for these analyses by their physicians. Analyses proved that 560 cases representing 75.2 % were anemic as the RBC(s) based on counts of the total studied cases of less than 263 x 10 4 and the haemoglobin amount ranged between 7.2 and 11.3 g/dl, while the remainder 24.8 % of the volunteer sample was not anemic. A high male/female ratio of anemic cases, 1:27 was also documented. Considering that all the studied stool samples should be completely free from any parasites or any other anemia-related diseases was a priority. Bacteriological analysis of stool samples of the anemic cases resulted in the detection of high counts of total viable bacteria, exceeded 42 x 10 9 cfu/g, while it was never more than 26 x 10 6 cfu/g and decreased to 4 x 10 6 cfu/g in many cases in this study. Identifying of the 361 bacterial isolates, were found to belong to 12 genera and 19 species, 6 of them; Pseudomonas putrefaciens, Micrococcus luteus, Erysipelothrix rhusiopathiae, Bacillus megaterium, Bacillus pumilus and Bacillus coagulans , were found and in high counts in the stool samples of only anemic cases. The ability of these isolates to compete for iron compounds such as ferrous fumarate alone or with glucose and phytate as activators or inhibitors to these abilities was investigated. Results proved 11 species out of the 19 identified species are capable to use and compete on ferrous fumarate as a haem precursor. Sensitivity test for the representatives of the 19 species and 6 of the most commonly used antibiotics in the Egyptian pharmacy, using standard disc method, revealed variable susceptibilities of almost all of them to more than one of the studied antibiotics, except Corynebacterium equatium, which was found very resistant to two antibiotics; colistin sulfate and erythrocin. Conclusion, significance and impact of study: The study finally concluded the strong role of intestinal bacterial counts and types as competitors on the haem precursor iron-containing compounds like ferrous fumarate.
Journal of Biological Sciences, May 15, 2002
Journal of International Environmental Application and Science, Apr 1, 2009
The principle drinking water sources at the Kingdom of Saudi Arabia (KSA), including Al-Madinah A... more The principle drinking water sources at the Kingdom of Saudi Arabia (KSA), including Al-Madinah Al-Mounwwarah are the desalinated and underground well water. The present study focused on evaluating this drinking water sources portability from the bacteriological point of view. Searching for any possible correlation between bacteria present in the studied drinking water and those which have been isolated from the final effluent waste water of hospitals, is a crucial target. Water samples were collected from underground well water, underground reservoirs and taps at the nearest neighbourhood to previously-studied five hospitals namely; King Fahd, Ohod, Al-Mouassat, Women and Maternity and Saudi-German. Water samples from two additional sites namely; Al-Eskan and Al-Bsateen, away from these hospitals were investigated as control remote areas. Drinking bottled water (6 trade marks) processed at Al-Madinah Al-Mounwwarah namely; Doraq, Nada, Quba, Sarat, Taibah and Watanya, were also studied. Qualitative and quantitative bacteriological full analyses for water samples collected from the 27 sites, including enumeration of total viable (TVB), total coliform (TC) and faecal coliform (FC) bacteria in addition to the identification of the purified isolates to the specific level using API 20E strips and its software program, have been accomplished. Antibiotic-resistance profiles, expressed in MIC µg/ml, of the most important Gram-ve rods against 9 antibiotics namely; bacitracin, chloramephincol, erythromycin, impenim, penicillin G, rifampicin, streptomycin, tetracycline and vancomycin, were also drown up. Screaning for plasmids in the antibiotic-resistant isolates was fully studied. Results showed high and fluctuated TVB, TC and FC bacterial counts ranged between 100 : 1000, 90 : 800 and 1 : 3 cfu/100 ml, respectively, in the studied underground well water, indicating its unacceptable quality for drinking. Underground reservoirs and tap water samples were free from TC and FC, giving acceptable drinking water according to both the local and international standards, although having low to moderate TVB counts (1 : 15 cfu/ 100 ml). No direct correlation between the bacterial counts and the neiborhood hospitals, compared with counts detected in water samples from the two remote control areas. The study clearly-assured the bacteriologically-high grade quality of all the six investigated bottled water, showing no counts for TC and/or FC, so safe to drink. The low TVB counts (3 : 24 cfu/ 100 ml) seemed, numerically-potable according to standards, but health threatens are alarming because of the ability of some of these commensals to accept extrachromosomal elements changing their characteristics and impose pathogenic behaviours. Identification revealed that 74% were Gram-ve, 56% of it are rods, while 18% are cocci, only 26% were Gram +ve rods, 19% are spore-formers and 7% are non spore-formers, while no Gram +ve cocci were detected. Gram-ve rods belonged to 8 strains, 7 species and 7 genera namely; Escherichia coli 1, Citrobacter frundii, Providencia stuartii, Proteus vulgaris, Cryseomonas leteula , Stenotrophomonas maltophili (which have been heavily-isolated from almost all the studied bottled water but non of the other sources), Aeromonas hydrophila (group 1&2). The most distributed species were Aeromonas hydrophila (group 1), Cryseomonas leteula and Stenotrophomonas maltophilia. All of the 8 studied strains resist from 3 : 9 of the antibiotics at MIC(s) from 50 :100 µg/ml. Molecular studies resulted in the detection of plasmids in 5 out of the 8 strains. Miniprep, alkaline lysis and 1% agarose gel protocols, along with electrophoresis against Hind III partially-digested Lambda phage, showed only one plasmid in each, all of the same size; 23130 bp. It is very important here to record that only 3 isolates namely; Escherichia coli 1, Provedencia stuartii and Stenotrophomonas maltophilia , out of 5 isolates of these were identical; from the points of antibiotic-resistance profiles, MIC(s) and plasmid content, with 3 of those isolated from hospitals waste water in the previous study.
European Chemical Bulletin, 2018
Qualitative and quantitative bacteriological analysis of the dialysate-water exhaust for the only... more Qualitative and quantitative bacteriological analysis of the dialysate-water exhaust for the only two haemodialysis units found at Al-Madinah Al-Mounwwarah, were studied. Ten samples were collected over 75 days, 5 times from each site of sampling on biweekly basis. Enumeration of total viable (TVB) and total coliform (TC) bacterial counts CFU/ ml, showed figures ranged from 0.0 to 5231x10 2 CFU /ml and from 0.0 to 73x10 2 CFU /ml, respectively. Specific identification of the isolated bacterial strains using API 20 E strips confirmed that isolated bacterial populations composed of 6 genera in one unit and 7 in the other. Bacterial diversity was relatively poor, but the counts were obviously-high.Determination of MIC(s), MBC(s) ,as well as, the MIC/MBC indexes for 153 representative strains of the bacterial population isolated in the study were done. All the studied strains exhibited resistance to at least 3, out of the 9 tested antibiotics up to MIC(S) > 100 μg/ml. [Atef M. Diab a...
Applied Biochemistry and Biotechnology, 2021
The cleaning activity of surface-active agents such as rhamnolipids (RLs) requires utmost effecti... more The cleaning activity of surface-active agents such as rhamnolipids (RLs) requires utmost effectiveness and is employed abundantly in various industries, particularly laundry cleaning, detergents, and cosmetics. In the current study, RLs were produced from Pseudomonas aeruginosa isolated from oil-contaminated soil using a minimal medium amended with agro-industrial by-products of refinery vegetable oil wastes (comprising of unsaturated types of fatty acids as determined by GC analysis) and dairy whey. The results showed that an amount of 5.72 g/L of RLs were obtained, while lower concentrations were obtained using chemically defined carbon sources. Ten congeners of mono- and di-RLs were detected by LC-MS, and they reduced the surface tension of water to 26 mN/m with a critical micelle concentration of 33 mg/L. Furthermore, the produced RLs showed promising cleaning and detergency properties in the removal of different stains on tested fabrics with a Stain Removal Index (SRI) of 17.45%. Moreover, an efficient cleaning was obtained when RLs were applied to a liquid detergent formulation model, and a cleaning power (∆E) of 245.95 and SRI of 36.28% were achieved. The present work showed that the produced RLs could be exploited as a powerful and alternative eco-friendly cleaning agent in many industries.
European Chemical Bulletin, 2018
Multiplex PCR for the detection of AmpC genes has proved useful as a rapid screening tool to dist... more Multiplex PCR for the detection of AmpC genes has proved useful as a rapid screening tool to distinguish cefoxitin resistant non-AmpC producers from cefoxitin resistant AmpC producers. In addition to AmpC gene detection, the data generated from the multiplex PCR method can distinguish which family of AmpC gene is present in the resistant organism thereby distinguishing possible inducible AmpC producers from non-inducible producers of AmpC. The present study was designed to evaluate these issues among cephalosporin-resistant isolates of Klebsiella spp. and to assess the performance characteristics of phenotypic tests, using different inhibitors, compared to the PCR, for their rapid and accurate detection. Fifty eight out of 100 isolates were AmpC producers by PCR. Fifty six out of 58 isolates that were positive by PCR test were resistant to FOX. Thirty out of 58 AmpC producers were ESBL positive by E-test and MDDST in detection of ESBL in the presence of AmpC. While 23 /58 were positive by DDST for detection of ESBL in presence of Amp. This study reveals high prevalence of pAmpC and ESBL enzymes among bacterial isolates from our hospital. ESBL production may mask the phenotypic detection of pAmpC enzymes. Modified 3 dimensional(M3D) is a simple and reliable method for detection of pAmpCs. MDDST serve as reliable confirmatory tests for detection of ESBLs in AmpC-positive isolates.
Egyptian Journal of Microbiology, 2020
T HE INTEREST in natural antimicrobial preservatives is rapidly grown due to their exceptional pr... more T HE INTEREST in natural antimicrobial preservatives is rapidly grown due to their exceptional properties such as biodegradability, biocompatibility, and lower toxicity. On the contrary, common synthesized preservatives are more toxic, partially or non-degradable, and have undesirable side effects on human health and the environment. Furthermore, the resistance of microorganisms to current antimicrobial preservatives is increasing. In the present study, rhamnolipid was produced from Pseudomonas aeruginosa ATCC 9027, and twelve congeners of rhamnolipids were elucidated by ESI-MS. Additionally, rhamnolipids reduced the surface tension of water to 26mN/m with a critical micelle concentration value of 22mg/L. The produced rhamnolipids showed prominent lower toxicity against the brine shrimp Artemia salina than those of positive control and methylisothiazolinone. A significantant antimicrobial effect of rhamnolipids was achieved in vitro, whereas the disc diffusion assay showed noticeable inhibition zones around the paper discs saturated with different concentrations of the rhamnolipid produced in this study, with MICs ranged between 8 and 336μg/ml against Escherichia coli, Salmonella typhimurium, Pseudomonas aeruginosa, Staphylococcus aureus, Bacillus subtilis, Saccharomyces cerevisiae, Candida albicans and Aspergillus brasiliensis. Moreover, a promising preservation efficacy of the produced rhamnolipid was obtained when applied to a personal care formulation model even after 28 days of incubation, with reduction values of about 3 and 1 expressed in log units for bacteria and fungi, respectively. However, rhamnolipids could be recommended as a powerful nontoxic bio-preservative for personal care formulations.
Egyptian Journal of Microbiology, 2020
estimated as deaths. In intensive care units (ICUs), Gram-negative pathogens are responsible for ... more estimated as deaths. In intensive care units (ICUs), Gram-negative pathogens are responsible for the majority of these deadly infections. Multidrug resistance (MDR) in the seorganisms has been attributed to production of modified enzymes responsible of elevated MICs and MBC/MICs putting them in the transient stages for persistence and tolerance. Bacterial cells those can survive high doses of antibiotics comprise a subpopulation of persistent but not resistant cells.Bacterial isolates (326) were collected from nosocomial infections via microbiology laboratories of police hospitals in Cairo. Frequency-wise, it was found that Escherichia is the most frequent (155), Pseudomonas (96), Staphylococcus (34), Klebsiella (24), Proteus (16) while Citrobacter is the least frequent (1). Pseudomonas, Klebsiella, Proteus and Citrobacter showed the highest MDRs, with the highest MICs in a descending order. Results clearly indicated the high risk of the two Pseudomonas aeruginosa from sputum and urine persisting (inhibited but not killed) against MICs 3 tested antibiotics; CRO, AMC and FEB. It is highly recommended here to run tests for MBC/MICs to choose the antibiotic with least MBC/MIC ratio; less than four, in order to reduce the transient persistent and/ or tolerant stages.
Malaysian Journal of Microbiology, 2012
The study focused on finding if there is any possible relation between the intestinal bacterial p... more The study focused on finding if there is any possible relation between the intestinal bacterial population quantitative and qualitative and the deficiency of the most important iron compounds as haem precursors. Methodology and Results: Blood complete picture and stool analyses were done to 750 volunteer cases whom were asked for these analyses by their physicians. Analyses proved that 560 cases representing 75.2 % were anemic as the RBC(s) based on counts of the total studied cases of less than 263 x 10 4 and the haemoglobin amount ranged between 7.2 and 11.3 g/dl, while the remainder 24.8 % of the volunteer sample was not anemic. A high male/female ratio of anemic cases, 1:27 was also documented. Considering that all the studied stool samples should be completely free from any parasites or any other anemia-related diseases was a priority. Bacteriological analysis of stool samples of the anemic cases resulted in the detection of high counts of total viable bacteria, exceeded 42 x 10 9 cfu/g, while it was never more than 26 x 10 6 cfu/g and decreased to 4 x 10 6 cfu/g in many cases in this study. Identifying of the 361 bacterial isolates, were found to belong to 12 genera and 19 species, 6 of them; Pseudomonas putrefaciens, Micrococcus luteus, Erysipelothrix rhusiopathiae, Bacillus megaterium, Bacillus pumilus and Bacillus coagulans , were found and in high counts in the stool samples of only anemic cases. The ability of these isolates to compete for iron compounds such as ferrous fumarate alone or with glucose and phytate as activators or inhibitors to these abilities was investigated. Results proved 11 species out of the 19 identified species are capable to use and compete on ferrous fumarate as a haem precursor. Sensitivity test for the representatives of the 19 species and 6 of the most commonly used antibiotics in the Egyptian pharmacy, using standard disc method, revealed variable susceptibilities of almost all of them to more than one of the studied antibiotics, except Corynebacterium equatium, which was found very resistant to two antibiotics; colistin sulfate and erythrocin. Conclusion, significance and impact of study: The study finally concluded the strong role of intestinal bacterial counts and types as competitors on the haem precursor iron-containing compounds like ferrous fumarate.
Egyptian Journal of Biology, Jul 13, 2004
Egyptian Journal of Biology Vol.3 2001: 59-6
Pakistan Journal of Biological Sciences, 2014