Abdu Aldarhami | Umm Al-Qura University, Makkah, Saudi Arabia (original) (raw)

Papers by Abdu Aldarhami

International Journal of Nanomedicine

Background: Conventional nanoparticle synthesis methods involve harsh conditions, high costs, and... more Background: Conventional nanoparticle synthesis methods involve harsh conditions, high costs, and environmental pollution. In this context, researchers are actively searching for sustainable, eco-friendly alternatives to conventional chemical synthesis methods. This has led to the development of green synthesis procedures among which the exploration of the plant-mediated synthesis of nanoparticles experienced a great development. Especially, because plant extracts can work as reducing and stabilizing agents. This opens up new possibilities for cost-effective, environmentally-friendly nanoparticle synthesis with enhanced size uniformity and stability. Moreover, bio-inspired nanoparticles derived from plants exhibit intriguing pharmacological properties, making them highly promising for use in medical applications due to their biocompatibility and nano-dimension. Objective: This study investigates the role of specific phytochemicals, such as phenolic compounds, terpenoids, and proteins, in plant-mediated nanoparticle synthesis together with their influence on particle size, stability, and properties. Additionally, we highlight the potential applications of these bio-derived nanoparticles, particularly with regard to drug delivery, disease management, agriculture, bioremediation, and application in other industries. Methodology: Extensive research on scientific databases identified green synthesis methods, specifically plant-mediated synthesis, with a focus on understanding the contributions of phytochemicals like phenolic compounds, terpenoids, and proteins. The database search covered the field's development over the past 15 years. Results: Insights gained from this exploration highlight plant-mediated green synthesis for cost-effective nanoparticle production with significant pharmacological properties. Utilizing renewable biological resources and controlling nanoparticle characteristics through biomolecule interactions offer promising avenues for future research and applications. Conclusion: This review delves into the scientific intricacies of plant-mediated synthesis of nanoparticles, highlighting the advantages of this approach over the traditional chemical synthesis methods. The study showcases the immense potential of green synthesis for medical and other applications, aiming to inspire further research in this exciting area and promote a more sustainable future.

Medicine

Successful empirical antibiotic therapy for infected patients with multi drug resistant bacteria ... more Successful empirical antibiotic therapy for infected patients with multi drug resistant bacteria (MDR) can be challenging task in various healthcare settings, including neonatal and pediatric intensive care units (NICU and PICU, respectively), unless an up-to-date comprehensive local antibiogram data is available. Thus, this project aimed to investigate the prevalence of MDR among PICU and NICU patients as well as the identification of risk factors associated with recovered MDR bacteria. This was a retrospective study of PICU and NICU patients admitted with bacterial infection of MDR organisms between October 2020 and May 2021. Frequency distribution, Chi-square test were applied to verify the significance differences among subgroups and to identify risk factor associated with each group. About 36.4% of recruited patients were neonates, while the remaining percentage (63.6%) were pediatric. The most predominant site of infection among these patients were revealed as urinary tract (3...

Pharmaceutics

Sidr honey is a valuable source of bioactive compounds with promising biological properties. In t... more Sidr honey is a valuable source of bioactive compounds with promising biological properties. In the present study, antimicrobial, antioxidant, and anti-quorum sensing properties of Saudi Sidr honey were assessed, along with phytochemical analysis, via gas chromatography–mass spectrometry (GC-MS). In silico study was also carried out to study the drug-likeness properties of the identified compounds and to study their affinity with known target proteins assessed using molecular docking approach. The results showed that Saudi Sidr honey exhibited promising antibacterial activity, with MIC values ranging from 50 to 400 mg/mL and MBC values from 50 to >450 mg/mL. Interestingly, the Saudi Sidr honey was active against Candida auris and Candida neoformans, with an MIC value of about 500 mg/mL. Moreover, the Sidr honey showed important antioxidant activities (ABTS assay: IC50 5.41 ± 0.045 mg/mL; DPPH assay: IC50 7.70 ± 0.065 mg/mL) and β-carotene bleaching test results (IC50 ≥ 20 mg/mL)....

Infection and Drug Resistance

Although Sumra and Sidr Saudi honey is widely used in traditional medicine due to its potent acti... more Although Sumra and Sidr Saudi honey is widely used in traditional medicine due to its potent activity, it is unknown whether its prolonged usage has impact upon bacterial virulence or leading to reduced antibiotic sensitivity. Thus, the study aims to investigate the effect of prolonged (repeated) in-vitro exposure to Saudi honey on the antibiotic susceptibility profiles and biofilm formation of pathogenic bacteria. Methods: Several bacteria, including Staphylococcus aureus, Escherichia coli, and Acinetobacter baumannii, were in-vitro exposed ten times [passaged (P10)]to Sumra and Sider honey individually to introduce adapted bacteria (P10). Antibiotic susceptibility profiles of untreated (P0) and adapted (P10) bacteria were assessed using disc diffusion and microdilution assays. The tendency regarding biofilm formation following in-vitro exposure to honey (P10) was assessed using the Crystal violet staining method. Results: Adapted (P10) bacteria to both Sumra and Sidr honey showed an increased sensitivity to gentamicin, ceftazidime, ampicillin, amoxycillin/clavulanic acid, and ceftriaxone, when compared with the parent strains (P0). In addition, A. baumannii (P10) that was adapted to Sidr honey displayed a 4-fold increase in the minimal inhibitory concentration of the same honey following in-vitro exposure. 3-fold reduction in the tendency toward biofilm formation was observed for the Sumra-adapted (P10) methicillin resistant S. aureus strain, although there was a lower rate of reduction (1.5-fold) in biofilm formation by both the Sumra-and Sidr-adapted A. baumannii (P10) strains. Conclusion: The data highlight the positive impact of prolonged in-vitro exposure to Saudi honey (Sumra and Sider) for woundassociated bacteria since they displayed a significant increase in their sensitivity profiles to the tested antibiotic and a reduction in their ability to form biofilm. The increased bacterial sensitivity to antibiotics and a limited tendency toward biofilm formation would suggest the great potential therapeutic use of this Saudi honey (Sumra and Sidr) to treat wound infections.

Edited version embargoed until 09.09.2022 Full version: Access restricted permanently due to 3rd ... more Edited version embargoed until 09.09.2022 Full version: Access restricted permanently due to 3rd party copyright restrictions. Restriction set on 11.09.2019 by SE, Doctoral College

The biological properties of plant oils are improved by their conversion to nanoemulsions (NEs). ... more The biological properties of plant oils are improved by their conversion to nanoemulsions (NEs). This study evaluated the antimicrobial, antioxidant, and anti-hemolytic efficacy of coconut and salad rocket oils and their NEs. The result of the gas chromatography-mass spectroscopy analysis of the oils showed varied constituents such as palmitic acid, trimethylsilyl ester; 2,3-bis(acetyloxy)propyl laurate in salad rocket oil, 2-lauro-1,3-didecoin, nbutyl laurate; laurin, tri-; laurin in coconut oil. NEs diameter of salad rocket and coconut oils was 24.6 and 29.2 nm, respectively. More inhibitory activity of NEs compared with non-NEs form against Bacillus cereus, Staphylococcus aureus, Escherichia coli, Salmonella typhi, Candida albicans, and Aspergillus flavus was detected. Coconut oil and its NEs caused 14.3% (anti-hemolysis 85.7%) and 22% hemolysis (anti-hemolysis 78%), respectively. Salad rocket oil and its NEs caused hemolysis 3.4% and 20.9%, respectively at 1000 µg/mL. Antioxidant activity of salad rocket and coconut oil reflected more IC50 (39.3 and 109.4 µg/mL) than its NEs (35.8 and 80.5 µg/mL), respectively. Molecular docking of trimethylsilyl ester and 2-lauro-1,3-didecoin against S. aureus (PDB=7BGE) and C. albicans protein (PDB=3DRA) revealed optimal binding mode that had the most energy interaction with the binding sites.

Molecules, Apr 21, 2023

This article is an open access article distributed under the terms and conditions of the Creative... more This article is an open access article distributed under the terms and conditions of the Creative Commons Attribution (CC BY

Journal of Chemistry

The nanostructures synthesized using the green chemistry method have recently attracted the atten... more The nanostructures synthesized using the green chemistry method have recently attracted the attention of scientists due to their significance in many scientific domains. This work provides an overview of the biosynthesis of zinc oxide (ZnO) nanosheets (NSs) using Phyllanthus emblica plant (PEP) extract. X-ray diffraction analysis (XRD), X-ray photoelectron spectroscopy (XPS), scanning electron microscopy (SEM), and Fourier transform infrared (FTIR) were used to analyze the synthesized ZnO-NSs. Evaluation of the antibacterial activity of biosynthesized ZnO-NSs was performed. ZnO-NSs exhibit effective antibacterial activity against Gram-positive (S. pyogenes and S. aureus) and Gram-negative (S. typhi and E. coli) bacterial strains. S. typhi is the most sensitive microbe towards ZnO-NSs and formed a 21 mm zone of inhibition (ZOI). ZnO-NSs are also tested as a photocatalyst in the degradation of methyl orange (MO) and rhodamine B (RB). The degradation rate of MO was 90%, and RB was 96% ...

BioResources

The biological properties of plant oils are improved by their conversion to nanoemulsions (NEs). ... more The biological properties of plant oils are improved by their conversion to nanoemulsions (NEs). This study evaluated the antimicrobial, antioxidant, and anti-hemolytic efficacy of coconut and salad rocket oils and their NEs. The result of the gas chromatography-mass spectroscopy analysis of the oils showed varied constituents such as palmitic acid, trimethylsilyl ester; 2,3-bis(acetyloxy)propyl laurate in salad rocket oil, 2-lauro-1,3-didecoin, n-butyl laurate; laurin, tri-; laurin in coconut oil. NEs diameter of salad rocket and coconut oils was 24.6 and 29.2 nm, respectively. More inhibitory activity of NEs compared with non-NEs form against Bacillus cereus, Staphylococcus aureus, Escherichia coli, Salmonella typhi, Candida albicans, and Aspergillus flavus was detected. Coconut oil and its NEs caused 14.3% (anti-hemolysis 85.7%) and 22% hemolysis (anti-hemolysis 78%), respectively. Salad rocket oil and its NEs caused hemolysis 3.4% and 20.9%, respectively at 1000 µg/mL. Antioxida...

BioMed Research International

Clinical multi-drug-resistant bacteria continue to be a serious health problem. Plant-derived mol... more Clinical multi-drug-resistant bacteria continue to be a serious health problem. Plant-derived molecules are an important source of bioactive compounds to counteract these pathogenic bacteria. In this paper, we studied the chemical composition of the methanol (80%) extract from Pithecellobium dulce seed (Hail, Saudi Arabia) and its ability to inhibit the growth of clinically relevant multi-drug-resistant bacteria. Molecular docking analysis was performed to predict the best compounds with low binding energy and high affinity to interact with two Staphylococcus aureus receptors. Data showed that P. dulce extract is a rich source of D-turanose (55.82%), hexadecanoic acid (11.56%), indole-1-acetic acid (11.42%), inositol (5.78%), and octadecanoic acid (4.36%). The obtained extract showed antibacterial activity towards tested clinical bacterial strains with MIC values ranging from 233 mg/mL for Acinetobacter baumannii to 300 mg/mL for S. aureus and Escherichia coli. Turanose interaction ...

Microorganisms

Infections caused by multi-drug-resistant bacteria in patients with chronic diseases have been as... more Infections caused by multi-drug-resistant bacteria in patients with chronic diseases have been associated with high mortality and morbidity. While few reports have evaluated bacterial infections in multiple chronic disease patients, the focus of the current study was to investigate the prevalence of bacterial infections and the susceptibility profiles of causative strains among various groups of patients suffering from chronic diseases. Microbiological reports of patients suffering from cancer, diabetes mellitus, cardiovascular diseases, kidney diseases, and skin burns were retrospectively collected from a tertiary hospital in Saudi Arabia. Approximately 54.2% of recruited patients were males, and positive urine was the most prevalent specimen associated with kidney disease patients (25%). Escherichia coli isolates were predominant among cardiovascular, kidney, and cancer patients. Staphylococcus aureus was commonly detected in diabetics and those with burns. Although resistance pat...

Microorganisms, 2022

While it is reported that COVID-19 patients are more prone to secondary bacterial infections, whi... more While it is reported that COVID-19 patients are more prone to secondary bacterial infections, which are strongly linked to the severity of complications of the disease, bacterial coinfections associated with COVID-19 are not widely studied. This work aimed to investigate the prevalence of bacterial coinfections and associated antibiotic resistance profiles among hospitalised COVID-19 patients. Age, gender, weight, bacterial identities, and antibiotic sensitivity profiles were collected retrospectively for 108 patients admitted to the intensive care unit (ICU) and non-ICU ward of a single center in Saudi Arabia. ICU patients (60%) showed a significantly higher percentage of bacterial coinfections in sputum (74%) and blood (38%) samples, compared to non-ICU. Acinetobacter baumannii (56%) and Klebsiella pneumoniae (56%) were the most prevalent bacterial species from ICU patients, presenting with full resistance to all tested antibiotics except colistin. By contrast, samples of non-ICU ...

PLOS ONE, 2020

The severe acute respiratory syndrome coronavirus-2 (SARS-CoV-2) is an emergent infectious pathog... more The severe acute respiratory syndrome coronavirus-2 (SARS-CoV-2) is an emergent infectious pathogen causing an acute respiratory disease called corona virus disease 2019 (COVID-19). Virus transmission may occur by contact, droplet, airborne or via contaminated surfaces. In efforts to effectively control the COVID-19 outbreak, the world health organization (WHO) and the Saudi Ministry of Health (MOH) have advised the public to practice protective measures to reduce transmission of the virus and reduce incidence of infection. These measures include hand washing, wearing masks and gloves and avoidance of touching the face with unwashed hands. The current study aimed to investigate knowledge and adherence of the Saudi population to these protective actions during the pandemic. After determining the required sample size using power analysis, a cross-sectional online self-reported survey of 5105 Saudi residents was conducted between 25th March to 17th April 2020 to evaluate public knowled...

Journal of Multidisciplinary Healthcare, 2021

Objective: Healthcare workers (HCWs) are the backbone of the healthcare system and a skilled and ... more Objective: Healthcare workers (HCWs) are the backbone of the healthcare system and a skilled and healthy workforce is vital during a health crisis, such as the present coronavirus disease 2019 (COVID-19) pandemic. Healthcare workers are at higher risk of exposure to and transmission of the severe acute respiratory coronavirus-2 (SARS-CoV-2). Hence, HCWs should possess good knowledge and attitudes toward COVID-19 to protect not only themselves but also their colleagues, families and the larger community. Thus, the current study aims to assess the knowledge and practice of protective measures by HCWs in Saudi Arabia during the first wave of the COVID-19 pandemic to identify awareness of the disease, potential trends and associated predictors. Methods: A cross-sectional, web-based study was conducted among HCWs about knowledge related to COVID-19 and practice of protective measures, such as social distancing and use of personal protective equipment (PPE) during the pandemic. A Fisher exact test and one-way analysis of variance (ANOVA) were used to investigate the level of association among variables. Results: A total of 674 HCWs were recruited in the study (51.8% male, 42.7% aged 28-37 years old and 52% specialists). The Saudi Ministry of Health (MoH) was the main source of knowledge for most of the HCWs (89%) followed by the WHO (44.5%) and social media (42.3%). Washing hands before touching the face was the most selected choice (97.9%) as a precautionary method to limit SARS-CoV2 transmission. Most of the HCWs (74.6%) scored low for staying at home while the majority (71.2%) showed a high practice of personal protective methods, with pharmacists and general physicians scoring the highest. Conclusion: Saudi HCWs showed high knowledge and practice of protective measures for COVID-19. Good knowledge correlates with adoption of appropriate practices to prevent spread of infection. The current findings highlight the importance of interventions such as tailored education and training courses for those with low scores to improve overall knowledge and practice.

Journal of Medical Microbiology, 2020

Introduction. Against the backdrop of increasing resistance to conventional antibiotics, bacterio... more Introduction. Against the backdrop of increasing resistance to conventional antibiotics, bacteriocins represent an attractive alternative, given their potent activity, novel modes of action and perceived lack of issues with resistance. Aim. In this study, the nature of the antibacterial activity of a clinical isolate of Streptococcus gallolyticus was investigated. Methods. Optimization of the production of an inhibitor from strain AB39 was performed using different broth media and supplements. Purification was carried out using size exclusion, ion exchange and HPLC. Gel diffusion agar overlay, MS/MS, de novo peptide sequencing and genome mining were used in a proteogenomics approach to facilitate identification of the genetic basis for production of the inhibitor. Results. Strain AB39 was identified as representing Streptococcus gallolyticus subsp. pasteurianus and the successful production and purification of the AB39 peptide, named nisin P, with a mass of 3133.78 Da, was achieved ...

Access Microbiology, 2019

Antimicrobial resistance (AMR) poses an ever-increasing threat to public health; the prevalence o... more Antimicrobial resistance (AMR) poses an ever-increasing threat to public health; the prevalence of resistant bacterial strains has reduced the clinical efficacy of many existing therapeutics and is therefore contributing to rising mortality rates due to difficult to treat bacterial infections. Two key approaches used to mitigate the threat of AMR are the discovery of novel therapeutics with activity against these resistant strains, and educating the wider public about the impact of AMR, and steps that can be taken to reduce the development of resistance. We are combining both approaches to enhance the impact of our public engagement activities. During a recent event at the University of Plymouth, a member of the public isolated the bacterial strain ‘36A’ from the button of a lift control panel. Simultaneous antagonistic screening identified antimicrobial activity against a range of both Gram-positive and Gram-negative bacteria. 36A was then subjected to draft genome sequence determination via the MinION platform (Oxford Nanopore). Growth media were optimised to enhance antimicrobial activity, with fermentation in LB broth and subsequent purification of the culture supernatant via multi-stage column chromatography resulting in the isolation of four putative antimicrobial compounds. Initial characterisation has shown that each compound has a peptidic component, all showing stability and potency at a relatively low concentration against MRSA, E. coli, Klebsiella pneumoniae and Pseudomonas aeruginosa. Structural characterisation has been carried out using mass spectrometry, with further characterisation and cell toxicity studies ongoing. The producing strain has been identified as a member of the Paenibacillus genus.

Access Microbiology, 2019

Background Natural product screening methods are arguably the most efficient way to identify nove... more Background Natural product screening methods are arguably the most efficient way to identify novel antibiotics. Exploiting obscure, hard to reach environments, implementing the latest high-throughput next generation sequencing techniques, performing in silico analysis and synthesis/recombinant expression of promising candidates may increase the discovery of unique agents. Materials/methods Deep-sea sponges were collected (∼1000 m depth) in the North Atlantic Ocean and bacteria were recovered. One strain (EU4) was selected for detailed analysis. Strain EU4 produced an inhibitor into liquid media. This compound was purified using liquid chromatography andmatrix-assisted laser desorption/ionization (MALDI) analysis was performed. In parallel, the draft genome was obtained and analysed using BAGEL-3 and anti SMASH-4.0mining tools. Successful synthetic production was obtained for a candidate identified using antiSMASH. Results Analysis ofthedraft genome (5.8Mbp) indicates that strain EU4is a novel member of the Bacillaceae. To date, the produced compound showed activity towards Micrococcus luteus only, while the synthetic compound displays a broad spectrum of activity towards Gram positive and negative bacteria. In addition, based on MALDI analysis, the synthetic and the naturally produced compounds possess different molecular weights, being approximately 4 kDa and 1.7 kDa, respectively. Conclusions Bacteria recovered from deep-sea sponges couldpotentially be a rich source for novel compounds. In silico analysis of producer genomes has provided a means of identifying cryptic compounds, not produced in culture. Further study of both compounds, which showed diverse activity spectra, may lead to promising new candidates for development into clinically relevant therapeutics.

International Journal of Nanomedicine

Medicine

Pharmaceutics

Infection and Drug Resistance

Molecules, Apr 21, 2023

Journal of Chemistry

BioResources

The biological properties of plant oils are improved by their conversion to nanoemulsions (NEs). ... more The biological properties of plant oils are improved by their conversion to nanoemulsions (NEs). This study evaluated the antimicrobial, antioxidant, and anti-hemolytic efficacy of coconut and salad rocket oils and their NEs. The result of the gas chromatography-mass spectroscopy analysis of the oils showed varied constituents such as palmitic acid, trimethylsilyl ester; 2,3-bis(acetyloxy)propyl laurate in salad rocket oil, 2-lauro-1,3-didecoin, n-butyl laurate; laurin, tri-; laurin in coconut oil. NEs diameter of salad rocket and coconut oils was 24.6 and 29.2 nm, respectively. More inhibitory activity of NEs compared with non-NEs form against Bacillus cereus, Staphylococcus aureus, Escherichia coli, Salmonella typhi, Candida albicans, and Aspergillus flavus was detected. Coconut oil and its NEs caused 14.3% (anti-hemolysis 85.7%) and 22% hemolysis (anti-hemolysis 78%), respectively. Salad rocket oil and its NEs caused hemolysis 3.4% and 20.9%, respectively at 1000 µg/mL. Antioxida...

BioMed Research International

Microorganisms

Microorganisms, 2022

PLOS ONE, 2020

Journal of Multidisciplinary Healthcare, 2021

Journal of Medical Microbiology, 2020

Access Microbiology, 2019