Browsing by Author "Nassar, Rania"

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Antimicrobial Activity of Phytic Acid: An Emerging Agent in Endodontics
(2021) Nassar, Rania; Naidoo, Nerissa; Kaklamanos, Eleftherios G; Senok, Abiola
Background: Phytic acid (IP6) is a promising and emerging agent, and because of its unique structure and distinctive properties, it lends itself to several applications in dentistry. Recently, IP6 was proposed as a potential chelating agent in endodontics. However, there is limited knowledge regarding its antimicrobial and antibiofilm effectiveness. The aims of this study, were therefore to evaluate the antimicrobial and antibiofilm activities of IP6 against a range of microbial species and compare these with ethylenediaminetetraacetic acid (EDTA) and sodium hypochlorite (NaOCl). The contact time required for IP6 to exert its bactericidal effect on Enterococcus faecalis was also determined. Methods: The inhibitory and biocidal activities of IP6, EDTA and NaOCl were assessed using a broth microdilution assay against 11 clinical and reference strains of bacteria and a reference strain of Candida albicans. The contact time required for various IP6 concentrations to eliminate planktonic cultures of E. faecalis was determined using a membrane filtration method according to BS-EN-1040:2005. IP6 bactericidal activity was also evaluated using fluorescent microscopy, and the antibiofilm activity of the test agents was also determined. Results: IP6 was biocidal against all tested microorganisms. At concentrations of 0.5%, 1% and 2%, IP6 required 5 min to exert a bactericidal effect on E. faecalis, while 5% IP6 was bactericidal after 30 s. IP6 also eradicated biofilms of the tested microorganisms. In conclusion, IP6 had notable antimicrobial effects on planktonic and biofilm cultures and exhibited rapid bactericidal effects on E. faecalis. This research highlighted, for the first time the antimicrobial and antibiofilm properties of IP6, which could be exploited, not only in dental applications, but also other fields where novel strategies to counter antimicrobial resistance are required.
Characterisation of S. aureus/ MRSA CC1153 and review of mobile genetic elements carrying the fusidic acid resistance gene fusC
(2021) Nassar, Rania; Senok, Abiola
Abstract: While many data on molecular epidemiology of MRSA are available for North America, Western Europe and Australia, much less is known on the distribution of MRSA clones elsewhere. Here, we describe a poorly known lineage from the Middle East, CC1153, to which several strains from humans and livestock belong. Isolates were characterised using DNA microarrays and one isolate from the United Arab Emirates was sequenced using Nanopore technology. CC1153 carries agr II and capsule type 5 genes. Enterotoxin genes are rarely present, but PVL is common. Associated spa types include t504, t903 and t13507. PVL-positive CC1153-MSSA were found in Egyptian cattle sufering from mastitis. It was also identifed among humans with skin and soft tissue infections in Saudi Arabia, France and Germany. CC1153-MRSA were mainly observed in Arabian Gulf countries. Some isolates presented with a previously unknown SCCmec/SCCfus chimeric element in which a mec B complex was found together with the fusidic acid resistance gene fusC and accompanying genes including ccrA/B-1 recombinase genes. Other isolates carried SCCmec V elements that usually also included fusC. Distribution and emergence of CC1153-MRSA show the necessity of molecular characterization of MRSA that are resistant to fusidic acid. These strains pose a public health threat as they combine resistance to beta-lactams used in hospitals as well as to fusidic acid used in the community. Because of the high prevalence of fusC-positive MRSA in the Middle East, sequences and descriptions of SCC elements harbouring fusC and/or mecA are reviewed. When comparing fusC and its surrounding regions from the CC1153 strain to available published sequences, it became obvious that there are four fusC alleles and fve distinct types of fusC gene complexes reminiscent to the mec complexes in SCCmec elements. Likewise, they are associated with diferent sets of ccrA/B recombinase genes and additional payload that might include entire mec complexes or SCCmec elements.
Coinfections in Patients Hospitalized with COVID-19: A Descriptive Study from the United Arab Emirates
(2021) Senok, Abiola; Nassar, Rania; Hachim, Mahmood Yaseen; Al Suwaidi, Hanan; Alsheikh-Ali, Alawi
Purpose: Microbial coinfections in COVID-19 patients carry a risk of poor outcomes. This study aimed to characterize the clinical and microbiological profiles of coinfections in patients with COVID-19. Methods: A retrospective review of the clinical and laboratory records of COVID-19 patients with laboratory-confirmed infections with bacteria, fungi, and viruses was conducted. Only adult COVID-19 patients hospitalized at participating health-care facilities between February 1 and July 31, 2020 were included. Data were collected from the centralized electronic system of Dubai Health Authority hospitals and Sheikh Khalifa General Hospital Umm Al Quwain. Results: Of 29,802 patients hospitalized with COVID-19, 392 (1.3%) had laboratory-confirmed coinfections. The mean age of patients with coinfections was 49.3±12.5 years, and a majority were male (n=330 of 392, 84.2%). Mean interval to commencement of empirical antibiotics was 1.2±3.6) days postadmission, with ceftriaxone, azithromycin, and piperacillin–tazobactam the most commonly used. Median interval between admission and first positive culture (mostly from blood, endotracheal aspirates, and urine specimens) was 15 (IQR 8–25) days. Pseudomonas aeruginosa, Klebsiella pneumoniae, and Escherichia coli were predominant in first positive cultures, with increased occurrence of Stenotrophomonas maltophilia, methicillin-resistant Staphylococcus aureus, Acinetobacter baumannii, Candida auris, and Candida parapsilosis in subsequent cultures. The top three Gram-positive organisms were Staphylococcus epidermidis, Enterococcus faecalis, and Staphylococcus aureus. There was variability in levels of sensitivity to antibiotics and isolates harboring mecA, ESBL, AmpC, and carbapenemase-resistance genes were prevalent. A total of 130 (33.2%) patients died, predominantly those in the intensive-care unit undergoing mechanical ventilation or extracorporeal membrane oxygenation. Conclusion: Despite the low occurrence of coinfections among patients with COVID-19 in our setting, clinical outcomes remained poor. Predominance of Gram-negative pathogens, emergence of Candida species, and prevalence of isolates harboring drug-resistance genes are of concern.
The Effect of Chlorhexidine on Bacterial Contamination of Hall Technique Elastomeric Orthodontic Separators and Gingival Health: A Pilot Study
(2023) AlNoman, Nada; Al Halabi, Manal; Kowash, Mawlood; Hassan Khamis, Amar; Salami, Anas; Senok, Abiola; Nassar, Rania; Hussein, Iyad
Objective: To study the effect of chlorhexidine on elastomeric orthodontic separators (EOS) bacterial-colonisation and gingival-health in Hall technique (HT) patients. Material and Methods: Prospective invivo pilot clinical study of EOS bacterial colonisation and primary-molar gingival health assessment in 20 patients (mean age 5.45±1.27 years) requiring bilateral HT crowns (40 teeth). One side received 1-minute 0.12% chlorhexidine-soaked-EOSs (Chx-EOSs), and the other side dry-EOSs (NoChx-EOSs). The EOSs were removed five-days later and underwent a bacterial enumeration technique. Plaque (PI) and Gingival (GI) indices were assessed pre-, five-days and three-months post-treatment. Wilcoxon-Signed-Rank/McNemar-Chi-square statistics were used (p<0.05). Results: Baseline unused/packaged EOSs’ sterility check yielded zero colony-forming-units (CFU) per millilitre, but 100% of the used EOSs became colonised by oral-microorganisms. An overall trend of lower mean CFU count in Chx-EOSs (3.415± 0.78 x105 CFU/ml) compared to NoChx-EOSs (6.157±1.48 x105 CFU/ml) was observed (p=0.009). Both NoChx-EOSs and ChxEOSs insertion sites showed evidence of gingivitis with no difference between PI and GI indices by site over time. Conclusion: There was a lower trend of bacterial colonization in chlorhexidine treated EOSs and an occurrence of gingivitis pre/post HT-treatment regardless of EOS type. The lack of difference in the gingival health may be inconclusive due to this pilot’s low power suggesting the need for robust large scale studies.
Genotyping of methicillin resistant Staphylococcus aureus from the United Arab Emirates
(2020) Senok, Abiola; Nassar, Rania
Abstract: Reports from Arabian Gulf countries have demonstrated emergence of novel methicillin resistant Staphylococcus aureus (MRSA) strains. To address the lack of data from the United Arab Emirates (UAE), genetic characterisation of MRSA identified between December 2017 and August 2019 was conducted using DNA microarray-based assays. The 625 MRSA isolates studied were grouped into 23 clonal complexes (CCs) and assigned to 103 strains. CC5, CC6, CC22 and CC30 represented 54.2% (n/N = 339/625) of isolates with other common CCs being CC1, CC8, CC772, CC361, CC80, CC88. Emergence of CC398 MRSA, CC5-MRSA-IV Sri Lanka Clone and ST5/ST225-MRSA-II, Rhine- Hesse EMRSA/New York-Japan Clone in our setting was detected. Variants of pandemic CC8-MRSA- [IVa + ACME I] (PVL+) USA300 were detected and majority of CC772 strains were CC772-MRSA-V (PVL+), “Bengal- Bay Clone”. Novel MRSA strains identified include CC5-MRSA-V (edinA+), CC5-MRSA- [VT + fusC], CC5-MRSA-IVa (tst1+), CC5-MRSA-[V/VT + cas + fusC + ccrA/B-1], CC8-MRSA-V/VT, CC22- MRSA-[IV + fusC + ccrAA/(C)], CC45-MRSA-[IV + fusC + tir], CC80-MRSA-IVa, CC121-MRSA-V/VT, CC152-MRSA-[V + fusC] (PVL+). Although several strains harboured SCC-borne fusidic acid resistance (fusC) (n = 181), erythromycin/clindamycin resistance (ermC) (n = 132) and gentamicin resistance (aacA-aphD) (n = 179) genes, none harboured vancomycin resistance genes while mupirocin resistance gene mupR (n = 2) and cfr gene (n = 1) were rare. An extensive MRSA repertoire including CCs previously unreported in the region and novel strains which probably arose locally suggest an evolving MRSA landscape.
Healthcare Derived Smart Watches and Mobile Phones are Contaminated Niches to Multidrug Resistant and Highly Virulent Microbes
(2022) Boucherabine, Syrine; Nassar, Rania; Mohamed, Lobna; Alqutami, Fatma; Zaher, Shroque; Hachim, Mahmood Yaseen; Senok, Abiola
Background: As high touch wearable devices, the potential for microbial contamination of smart watches is high. In this study, microbial contamination of smart watches of healthcare workers (HCWs) was assessed and compared to the individual’s mobile phone and hands. Methods: This study was part of a larger point prevalence survey of microbial contamination of mobile phones of HCWs at the emergency unit of a tertiary care facility. Swabs from smart watches, mobile phones and hands were obtained from four HCWs with dual ownership of these digital devices. Bacterial culture was carried out for all samples and those from smart watches and mobile phones were further assessed using shotgun metagenomic sequencing. Results: Majority of the participants were females (n/N = 3/4; 75%). Although they all use their digital devices at work and believe that these devices could harbour microbes, cleaning in the preceding 24 hours was reported by one individual. Predominant organisms identified on bacterial culture were multidrug resistant Staphylococcus hominis and Staphylococcus epidermidis. At least one organism identified from the hands was also detected on all mobile phones and two smart watches. Shotgun metagenomics analysis demonstrated greater microbial number and diversity on mobile phones compared to smart watches. All devices had high signatures of Pseudomonas aeruginosa and associated bacteriophages and antibiotic resistance genes. Almost half of the antibiotic resistance genes (n/N = 35/75;46.6%) were present on all devices and majority were related to efflux pumps. Of the 201 virulence factor genes (VFG) identified, majority (n/N = 148/201;73%) were associated with P. aeruginosa with 96% (n/N = 142/148) present on smart watches and mobile phones. Conclusion: This first report on microbial contamination of smart watches using metagenomics next generation sequencing showed similar pattern of contamination with microbes, VFG and antibiotic resistance genes across digital devices. Further studies on microbial contamination of wearable digital devices are urgently needed.
Lateral Flow Immunoassay for the Detection of Panton-Valentine Leukocidin in Staphylococcus aureus From Skin and Soft Tissue Infections in the United Arab Emirates
(2021) Senok, Abiola; Nassar, Rania; Celiloglu, Handan
Introduction: Panton Valentine leukocidin (PVL) is a virulence factor which is associated with methicillin sensitive and resistant Staphylococcus aureus (MSSA/MRSA) causing skin and soft tissue infections (SSTI). This study aimed to evaluate a novel lateral flow immunoassay (LFI) for PVL detection in S. aureus cultures and to describe their genotypic characterization. Methods: The study was carried out from January-August 2020 in Dubai, United Arab Emirates. S. aureus isolates associated with SSTI were tested for PVL detection using LFI. DNA microarray-based assays were used for molecular characterization including detection of pvl genes. Results: One-hundred thirty-five patients with a clinical diagnosis of SSTIs were recruited. Sixty-six patients received antibiotics, mostly beta lactams (n=36) and topical fusidic acid (n=15). One-hundred twenty-nine isolates (MRSA: n=43; MSSA: n=86) were tested by LFI and DNA microarrays. All 76 (58.9%) isolates which were unambiguously negative for the PVL in LFI were negative for pvl genes using the DNA microarray. All the LFI PVL positive isolates (n=53) had pvl genes detected. This translates into 100% each for sensitivity, specificity, positive and negative predictive values for the LFI. The LFI typically takes about 15 min inclusive of a 10 min incubation period. Predominant S. aureus clonal complexes (CC) were CC30 (n=18), CC22 (n=13), CC5 (n=12), CC1 (n=11), CC152 (n=8), CC15 (n=7); CC97 (n=7); CC8 and CC20 (n=6 each). Among MRSA, the proportion of pvlpositives (35/43; 81%) was higher than among MSSA (n/N=18/86; 21%). The fusidic acid resistance gene fusC was detected in 14 MRSA (33%) compared to 8 MSSA (9%). A cocarriage of fusC and pvl genes was present in 7 MRSA and in one MSSA. Conclusion: LFI shows excellent diagnostic accuracy indices for rapid identification of PVL in MSSA/MRSA in a setting with high prevalence of pvl+ve strains. The high occurrence of pvl and fusC genes in MRSA strains causing SSTI is of concern and needs constant surveillance.
Metagenomic Sequencing and Reverse Transcriptase PCR Reveal That Mobile Phones and Environmental Surfaces Are Reservoirs of Multidrug-Resistant Superbugs and SARS-CoV-2
(2022) Boucherabine, Syrine; Nassar, Rania; Zaher, Shroque; Mohamed, Lobna; Alqutami, Fatma; Hachim, Mahmood Yaseen; Senok, Abiola
Background: Mobile phones of healthcare workers (HCWs) can act as fomites in the dissemination of microbes. This study was carried out to investigate microbial contamination of mobile phones of HCWs and environmental samples from the hospital unit using a combination of phenotypic and molecular methods. Methods: This point prevalence survey was carried out at the Emergency unit of a tertiary care facility. The emergency unit has two zones, a general zone for non-COVID-19 patients and a dedicated COVID-19 zone for confirmed or suspected COVID-19 patients. Swabs were obtained from the mobile phones of HCWs in both zones for bacterial culture and shotgun metagenomic analysis. Metagenomic sequencing of pooled environmental swabs was conducted. RT-PCR for SARS-CoV-2 detection was carried out. Results: Bacteria contamination on culture was detected from 33 (94.2%) mobile phones with a preponderance of Staphylococcus epidermidis (n/N = 18/35), Staphylococcus hominis (n/N = 13/35), and Staphylococcus haemolyticus (n/N = 7/35). Two methicillinsensitive and three methicillin-resistant Staphylococcus aureus, and one pan-drugresistant carbapenemase producer Acinetobacter baumannii were detected. Shotgun metagenomic analysis showed high signature of Pseudomonas aeruginosa in mobile phone and environmental samples with preponderance of P. aeruginosa bacteriophages. Malassezia and Aspergillus spp. were the predominant fungi detected. Fourteen mobile phones and one environmental sample harbored protists. P. aeruginosa antimicrobial Frontiers in Cellular and Infection Microbiology | www.frontiersin.org March 2022 | Volume 12 | Article 806077 1 Edited by: Krisztina M. Papp-Wallace, Louis Stokes Cleveland VA Medical Center, United States Reviewed by: Diogo Pratas, University of Aveiro, Portugal Monika Muzslay, University College London Hospitals NHS Foundation Trust, United Kingdom *Correspondence: Abiola Senok abiola.senok@mbru.ac.ae † These authors have contributed equally to this work and share first authorship Specialty section: This article was submitted to Clinical Microbiology, a section of the journal Frontiers in Cellular and Infection Microbiology Received: 31 October 2021 Accepted: 24 January 2022 Published: 08 March 2022 Citation: Boucherabine S, Nassar R, Zaher S, Mohamed L, Olsen M, Alqutami F, Hachim M, Alkhaja A, Campos M, Jones P, McKirdy S, Alghafri R, Tajouri L and Senok A (2022) Metagenomic Sequencing and Reverse Transcriptase PCR Reveal That Mobile Phones and Environmental Surfaces Are Reservoirs of Multidrug-Resistant Superbugs and SARS-CoV-2. Front. Cell. Infect. Microbiol. 12:806077. doi: 10.3389/fcimb.2022.806077 ORIGINAL RESEARCH published: 08 March 2022 doi: 10.3389/fcimb.2022.806077 resistance genes mostly encoding for efflux pump systems were detected. The P. aeruginosa virulent factor genes detected were related to motility, adherence, aggregation, and biofilms. One mobile phone from the COVID-19 zone (n/N = 1/5; 20%) had positive SARS-CoV-2 detection while all other phone and environmental samples were negative. Conclusion: The findings demonstrate that mobile phones of HCWs are fomites for potentially pathogenic and highly drug-resistant microbes. The presence of these microbes on the mobile phones and hospital environmental surfaces is a concern as it poses a risk of pathogen transfer to patients and dissemination into the community.
Microbial Metabolic Genes Crucial for S. aureus Biofilms: An Insight From Re-analysis of Publicly Available Microarray Datasets
(2021) Nassar, Rania; Hachim, Mahmood Yaseen; Kaklamanos, Eleftherios G; Jamal, Mohamed; Senok, Abiola
Abstract: Bacterial biofilms are microbial lifestyles found in all environments. Up to 80% of human infections and 60–70% of hospital-acquired infections have a biofilm origin, with Staphylococcus aureus one of the leading causes of these infections. Microorganisms in biofilms exhibit significant antimicrobial resistance which poses important treatment challenges, hence the urgent need to identify novel antibiofilm strategies. Microbes form biofilms in response to various factors, and once these 3-dimentional structures form they are highly recalcitrant to removal. The switch from planktonic lifestyle to the biofilm protected mode of growth results in a phenotypic shift in the behavior of the microorganisms in terms of growth rate and gene expression. Given these changes, investigation of microbial gene expression and their modulation at different stages of biofilm maturation is needed to provide vital insight into the behavior of biofilm cells. In this study, we analyzed publicly available transcriptomic dataset of S. aureus biofilms at different stages of maturation to identify consistently upregulated genes irrespective of the biofilm maturation stage. Our reanalysis identified a total of 6 differentially expressed genes upregulated in both 48 and 144-h old S. aureus biofilms. Functional analysis revealed that these genes encode for proteins which play a role in key microbial metabolic pathways. However, these genes, as yet, are unrelated or fully studied in the context of biofilm. Moreover, the findings of this in silico work, suggest that these genes may represent potential novel targets for the development of more effective antibiofilm strategies against S. aureus biofilm-associated infections.
Mobile phones are hazardous microbial platforms warranting robust public health and biosecurity protocols
(2022) Nassar, Rania; Senok, Abiola
Introduction: Advancements in technology and communication have revolutionised the twenty-frst century with the introduction of mobile phones and smartphones. These phones are known to be platforms harbouring microbes with recent research shedding light on the abundance and broad spectrum of organisms they harbour. Mobile phone use in the community and in professional sectors including health care settings is a potential source of microbial dissemination. To identify the diversity of microbial genetic signature present on mobile phones owned by hospital medical staf. Twenty-six mobile phones of health care staf were swabbed. DNA extraction for downstream next generation sequencing shotgun metagenomic microbial profling was performed. Survey questionnaires were handed to the staf to collect information on mobile phone usage and users’ behaviours. Each of the 26 mobile phones of this study was contaminated with microbes with the detection of antibiotic resistance and virulent factors. Taken together the sum of microbes and genes added together across all 26 mobile phones totalised 11,163 organisms (5714 bacteria, 675 fungi, 93 protists, 228 viruses, 4453 bacteriophages) and 2096 genes coding for antibiotic resistance and virulent factors. The survey of medical staf showed that 46% (12/26) of the participants used their mobile phones in the bathroom. Mobile phones are vectors of microbes and can contribute to microbial dissemination and nosocomial diseases worldwide. As fomites, mobile phones that are not decontaminated may pose serious risks for public health and biosecurity.
Mobile phones as fomites for pathogenic microbes: A cross-sectional survey of perceptions and sanitization habits of health care workers in Dubai, United Arab Emirates
(2022-08) Nassar, Rania; Boucherabine, Syrine; Senok, Abiola
Backgrounds: In 2022, smartphone use continues to expand with the number of smartphone subscriptions surpassing 6 billion and forecasted to grow to 7.5 billion by 2026. The necessity of these ‘high touch’ devices as essential tools in professional healthcare settings carries great risks of cross-contamination between mobile phones and hands. Current research emphasises mobile phones as fomites enhancing the risk of nosocomial disease dissemination as phone sanitisation is often overlooked. To assess and report via a large-scale E-survey the handling practices and the use of phones by healthcare workers. Methods: A total of 377 healthcare workers (HCWs) participated in this study to fill in an E-survey online consisting of 14 questions (including categorical, ordinal, and numerical data). Analysis of categorical data used non-parametric techniques such as Pearson’s chi-squared test. Results: During an 8-h shift, 92.8% (n/N Z 350/377) use their phone at work with 84.6% (n/ N Z 319/377) considering mobile phones as an essential tool for their job. Almost all HCWs who participated in this survey believe their mobile phones could potentially harbour microorganisms (97.1%; n/N Z 366/377). Fifty-seven respondents (15.1%) indicated that they use their phones while wearing gloves and 10.3% (n/N Z 39/377) have never cleaned their phones. The majority of respondents (89.3%; n/N Z 337/377) agreed that contaminated mobile phones could contribute to dissemination of SARS-CoV-2. Conclusion: Mobile phone use is now almost universal and indispensable in healthcare. Medical staff believe mobile phones can act as fomites with a potential risk for dissemination of microbes including SARS-COV-2. There is an urgent call for the incorporation of mobile phone sanitisation in infection prevention protocol. Studies on the use of ultraviolet-C based phone sanitation devices in health care settings are needed.
Molecular Characterization of Staphylococcus aureus Isolates Associated with Nasal Colonization and Environmental Contamination in Academic Dental Clinics
(2020) Senok, Abiola; Kaklamanos, Eleftherios G; Nassar, Rania; Belhoul, Khawla
Aim: To determine the genetic makeup of methicillin-sensitive/methicillin-resistant Staphylococcus aureus (MSSA/MRSA) from nasal colonization and environmental contamination in dental clinics. Materials and Methods: Nasal swabs from students and health care workers and environmental swabs were obtained at two academic dental clinics in the United Arab Emirates. The StaphyType DNA microarray-based assay was used for molecular characterization. Results: Forty-eight S. aureus isolates were identified phenotypically (nasal: n = 43; environmental: n = 5), but 6 of these were assigned to S. argenteus by genotyping. These were CC(argenteus)2596, CC(arg)2250-MSSA, CC(arg)2250-MSSA-(Panton Valentine leukocidin [PVL]+) (n = 2), and CC(arg)2198-MSSA (n = 2). MRSA nasal colonization rate was 5.4% (n/N = 8/146) with the following strain affiliations: CC5-MRSA-[IV+fus+ccrAB], ‘‘Maltese Clone’’; CC6-MRSA-IV, ‘‘WA MRSA-51’’; CC22-MRSA-IV (PVL+/tst+); CC22-MRSA-[IV+ fus+ccrAA/(C)]; and two each of CC5-MRSA-[VI+fus] and CC97-MRSA-[V/VT+fus]. The SCC-borne fusidic acid resistance (fusC) gene was detected in MRSA (n = 5) and MSSA (n = 1). Some MSSA strains, CC1-MSSA- [fus+ccrAB1] and ST1278-MSSA-[ccrA1], harbored recombinase genes. A CC30-MSSA harbored ACME locus/arc-genes, while ST1278-MSSA-[ccrA1] had an ACME-III element. Enterotoxin genes were commonly carried, but tst-1 gene was found in only CC22, CC30, and CC34 strains, while pvl genes were identified in CC(arg)2250 and CC22-MRSA-IV. Of the 51 noncoagulase staphylococci (CoNS) identified, 18 were mecA positive. Conclusion: The findings demonstrate the first report of rare strains (ST1278 MSSA, CC(arg)2198, CC(arg)2596, and PVL+CC(arg)2250) in our region. Detection of MSSA with recombinase genes and ACME loci alongside mecA-positive CoNS is of clinical significance as this could provide a milieu for acquisition and transfer of SCC-elements, either with different ACME types, with fusC or the mecA gene resulting in conversion of MSSA into MRSA.
Phytic Acid Demonstrates Rapid Antibiofilm Activity and Inhibits Biofilm Formation When Used as a Surface Conditioning Agent
(2023) Nassar, Rania; Senok, Abiola
Abstract: Root canal infections are associated with biofilms and are treated with chemical irrigants with a high success rate. However, treatment failure does arise, which is attributed primarily to resistance exhibited by biofilms. Currently used irrigants in root canal treatment have disadvantages, and there is therefore a need for more biocompatible alternatives with antibiofilm properties to reduce root canal treatment failure and complications. The aim of this study was to evaluate the in vitro antibiofilm properties of phytic acid (IP6), which is a potential alternative treatment agent. Singleand dual-species biofilms of Enterococcus faecalis and Candida albicans were developed on the well surfaces of 12-well plates and on hydroxyapatite (HA) coupons, and then exposed to IP6. In addition, selected HA coupons were preconditioned with IP6 before biofilm development. IP6 demonstrated bactericidal effects and altered the metabolic activity of biofilm cells. Confocal laser-scanning microscopy showed that IP6 caused significant and rapid reduction in live biofilm cells. At sublethal concentrations, IP6 did not alter the expression of tested virulence genes except for C. albicans hwp1, the expression of which was upregulated but not reflected by a change in hyphal transformation. IP6-preconditioned HA coupons led to extensive inhibition of dual-species biofilm formation. The results of this study highlight for the first time the antibiofilm inhibitory properties of IP6 and the potential for its exploitation in several clinical applications.
Phytic acid effect on periodontal ligament fibroblast: An in-vitro study
(2023-12) Nassar, Rania
Abstract: Objectives: This study evaluated phytic acid (IP6) effect on the viability, alkaline phosphatase (ALP) activity and calcium release of human periodontal ligament (HPDL) cells in optimal (OGL) and elevated glucose level (EGL) in cell culture media. Materials and methods: Cells were seeded in OGL (1000mg/L) or EGL (4500 mg/L) media. IP6 was added at 0.005%, 0.01% or 0.02% concentrations for 24 or 48h, and XTT assay was performed. Cell differentiation and calcium release in presence of 0.02% IP6 in OGL or EGL in non-osteogenic or osteogenic media were analyzed using ALP assay and alizarin red staining, respectively. Results: In OGL, IP6 enhanced the viability of the cells at both exposure times (P<0.05). However, IP6 lowered the viability of the cells with the presence of EGL compared to the control at both exposure times, except for 0.02% IP6 which showed comparable viability to the control at 48 h. In OGL and EGL, ALP activity of the cells was not affected by the presence of IP6 in non-osteogenic media; however, in osteogenic media IP6 lowered the ALP activity. Meanwhile, calcium release was the highest with IP6 within osteogenic media of EGL. Conclusions: IP6 effects on the HPDL cells were dependent on IP6 concentration, time of exposure, glucose levels and the osteogenic condition of the media.
Phytic Acid: Properties and Potential Applications in Dentistry
(2021) Nassar, Rania; Hachim, Mahmood Yaseen
Abstract: Inositol hexaphosphate (IP6) is the most abundant inositol phosphate in nature and an essential molecule for different biological functions. IP6 has a unique structure granting it distinctive properties; a high negative charge density provides IP6 with an immense chelating ability and valuable antioxidant properties. IP6 is also simple and cost-effective to produce. These features have attracted researchers and entrepreneurs to further study IP6 for a wide variety of applications in areas such as pharmaceutical, food and chemical industries, medicine, pharmacy, nutrition, and dentistry. The interest in IP6 in the dental field unfolded many decades ago following identification of a cariostatic ability and a positive impact on reducing enamel dissolution. Subsequently, IP6’s anti-plaque, anticalculus and cement-forming properties have been investigated. Despite encouraging findings, there was a phase of decreased attention to IP6 which slowed down research progress. However, the potential use of IP6 has recently been revisited through several publications that provided deeper understanding into its mechanisms of action in the aforementioned applications. Studies have also explored new applications in endodontics, adhesive, preventive and regenerative dentistry, and IP6’s role in improving the characteristics and performance of dental materials. Evidence of the merits of IP6 in dentistry is now substantial, and this narrative review presents and discusses the different applications proposed in the literature and gives insights of future use of IP6 in the fields of orthodontics, implant and pediatric dentistry.
A pilot metagenomic study reveals that community derived mobile phones are reservoirs of viable pathogenic microbes
(2021) Senok, Abiola; Nassar, Rania
Abstract: There is increasing attention focussed on the risks associated with mobile phones possibly serving as ‘Trojan Horse’ fomites for microbial transmission in healthcare settings. However, little is reported on the presence of microbes on community derived mobile phones which in 2021, numbered in the billions in circulation with majority being used on a daily basis. Identify viable microbial organisms swabbed from smartphones on a university campus. Entire surfaces of 5 mobile phones were swabbed and examined for their microbial content using pre-agar-based growths followed by downstream DNA metagenomic next-generation sequencing analysis. All phones were contaminated with viable microbes. 173 bacteria, 8 fungi, 8 protists, 53 bacteriophages, 317 virulence factor genes and 41 distinct antibiotic resistant genes were identified. While this research represents a pilot study, the snapshot metagenomic analysis of samples collected from the surface of mobile phones has revealed the presence of a large population of viable microbes and an array of antimicrobial resistant factors. With billions of phones in circulation, these devices might be responsible for the rise of community acquired infections. These pilot results highlight the importance of public health authorities considering mobile phones as ‘Trojan Horse’ devices for microbial transmission and ensure appropriate decontamination campaigns are implemented.
A single-centre investigator-blinded randomised parallel group clinical trial to investigate the effect of probiotic strains Streptococcus salivarius M18 and Lactobacillus acidophilus on gingival health of paediatric patients undergoing treatment with fixed orthodontic appliances: study protocol
(2019) Kaklamanos, Eleftherios G; Nassar, Rania; Al Halabi, Manal; Kowash, Mawlood; Hannawi, Haifa; Hussein, Iyad; Salami, Anas; Hassan Khamis, Amar; Senok, Abiola C
Background: There is limited data on the beneficial effects of probiotics on the gingival health of patients undergoing treatment with fixed orthodontic appliances. This study aims to compare the effect of probiotic tablets combined with regular oral hygiene versus regular oral hygiene alone on gingival status in these patients. The effect of probiotic intake on plaque formation and salivary microbiome composition will be also assessed. Methods and analysis: This is a 3 month single-centre, single blind (clinical and laboratory examiners), parallel group randomised controlled two arm superiority trial. Fifty paediatric patients attending the Postgraduate Orthodontic Clinic at the Hamdan Bin Mohammed College of Dental Medicine (HBMCDM), Mohammed Bin Rashid University of Medicine and Health Sciences (MBRU), Dubai, United Arab Emirates, who meet the eligibility criteria will be recruited. Block randomisation with 1:1 allocation and concealment of allocation will be carried out. The treatment group will receive probiotic tablets containing Streptococcus salivarius M18 and Lactobacillus acidophilus together with regular oral hygiene versus the control group on regular oral hygiene alone. Clinical examination and collection of saliva formicrobiome assay will be carried out at baseline and end of study. Self-reporting by patients will be used to document acceptability and adverse effects. Statistically significant decrease in gingival bleeding on probing in the treatment group will be classified as primary outcome of treatment success. Statistically significant reduction in Plaque Index, Gingival Index and shift in the composition of the oral microbiome in favour of beneficial bacteria are secondary outcomes indicative of efficacy of probiotic intake. Ethics and dissemination: Ethical approval for the study has been granted by the HBMCDM, MBRU, Institutional Review Board (Reference #: MBRU-IRB-2018–015). Study findings will be disseminated via publication in peerreviewed journal.
Ultraviolet-C-Based Mobile Phone Sanitisation for Global Public Health and Infection Control
(2023) Nassar, Rania; Senok, Abiola
Abstract: Introduction. Mobile phones act as fomites that pose a global public health risk of disseminating microorganisms, including highly pathogenic strains possessing antimicrobial resistances. The use of ultraviolet-C (UV-C) to sanitise mobile phones presents an alternative means to complement basic hand hygiene to prevent the cross-contamination and dissemination of microorganisms between hands and mobile phones. Aim. This study aimed to evaluate the germicidal efficacy of the Glissner CleanPhone UV-C phone sanitiser (Glissner) device. Methods. Two experimental trials were performed for the evaluation of the CleanPhone (Glissner). The first was a controlled trial, where the germicidal efficacy of the CleanPhone was evaluated against six different microorganism species that were inoculated onto mobile phones. The second was a field trial evaluating the germicidal efficacy of the CleanPhone on 100 volunteer mobile phones. Efficacy was determined based on colony counts of microorganisms on Columbia sheep blood agar before and after UV-C treatment. Results. In the controlled trial, reduction in growth was observed for all microorganisms after UV-C treatment with ST131 Escherichia coli showing the highest growth reduction at 4 log10 CFU/mL followed by C. albicans and ATCC E. coli at 3 log10 CFU/mL. An overall reduction in microorganism growth after UV-C treatment was also observed for the field trial, with an average growth reduction of 84.4% and 93.6% in colony counts at 24 h and 48 h post-incubation, respectively. Conclusion. The findings demonstrated the capability of the CleanPhone (Glissner) to rapidly sanitise mobile phones, thereby providing a means to reduce the potential dissemination of microorganisms, including highly pathogenic strains with antimicrobial resistance.