Antimicrobial effect of phytic acid on Enterococcus faecalis

Objective One of the properties of an ideal root canal irrigant is the ability to eradicate Enterococcus faecalis which is one of the most resistant microorganisms encountered in persistent peri-radicular lesions. The aim of this study was to test the in vitro antibacterial effectiveness of a naturally occurring agent called phytic acid (IP6) against E. faecalis and compare it to the antibacterial activities of clinically used irrigants: sodium hypochlorite (NaOCl), ethylenediaminetetraacetic (EDTA), phosphoric acid (PA) and chlorhexidine (CHX). Design The antimicrobial activities of 5% IP6, 5% NaOCl, 18% EDTA, 37% PA and 2% CHX against E. faecalis were determined using disk diffusion test. Minimum inhibitory concentration (MIC) was calculated by broth macrodilution method. The minimal bactericidal concentration (MBC) was determined for the used agents by culturing the clear broth of MIC tests. Results The results of agar diffusion test showed statistically signiï¬cant differences between the groups. PA showed a larger zone when compared to other tested materials (p< 0.05). There was no statistical significant difference between NaOCl, EDTA and CHX (p=0.098). IP6 showed the smallest zone of inhibition when compared to all groups (p< 0.05).The recorded MIC and MBC values for IP6 were 0.156% and 0.625%; respectively. The MIC and MBC values for PA were 0.578% and 4.6% and for NaOCl 0.093% and 0.375%, respectively. EDTA MIC value was 0.14 % but it showed no bactericidal activity. CHX was excluded from MIC test as immediate precipitation and turbidity occurred after mixing CHX with Mueller Hinton Broth. Conclusions Within the limitation of this study and despite that IP6 showed the smallest zone of inhibition in agar diffusion test, the results of MIC and MBC indicated that IP6 exhibits in vitro antibacterial effect against E. faecalis at low concentrations

Phytic acid demonstrates rapid antibiofilm activity and inhibits biofilm formation when used as a surface conditioning agent

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. Single- and 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

Antimicrobial activity of phytic acid: an emerging agent in dentistry

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

Multi criteria governmental crop planning problem: an analytic hierarchy approach

The goal of this study is to rank crops to cultivate in the governmental agricultural lands in Gaza Strip using AHP methodology as a Multi Criteria Decision Making (MCDM) tool. This study is applied under the normal condition, from the governmental point of view. Seven main criteria were first identified consisting of economical, financial, marketing, environmental, technical, political, and social criteria, while thirty one sub-criteria were then identified. Crops were divided into eight types that include vegetables, fruits, citrus, olives, palms, export crops, field crops and medical and aromatic crops. The results indicate that the economic criteria are the most important criteria as they represent 0.33 of the total weight, while the technical criteria are the least important criteria as they represent 0.07 of the total weight. Sub-criteria weights indicate that the contribution to GDP sub-criterion is the most important one with respect to the goal as it has 0.103 of the total weight. Cropping pattern is skewed towards export crops, citrus and vegetables

Microbial metabolic genes crucial for S. aureus biofilms: an insight from re-analysis of publicly available microarray datasets

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 behaviour of biofilm cells. In this study, we analysed publicly available transcriptomic dataset of S. aureus biofilm 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 poorly 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

The Effect of Chlorhexidine on Bacterial Contamination of Hall Technique Elastomeric Orthodontic Separators and Gingival Health: A Pilot Study

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 in-vivo 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 Chx-EOSs 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

Phytic acid: properties and potential applications in dentistry

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; the 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, anti-calculus 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 to 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 insight of future use of IP6 in the fields of orthodontics, implant and pediatric dentistry

Multi Criteria Governmental Crop Planning Problem: an Analytic Hierarchy Approach

Abstract The goal of this study is to rank crops to cultivate in the governmental agricultural lands in Ga za St rip using AHP methodology as a Multi Criteria Decision Making (M CDM) tool. Th is study is applied under the normal condition, fro m the governmental point of view. Seven ma in criteria were first identified consisting of economical, financial, market ing, environ mental, technical, political, and social criteria, while thirty one sub-criteria were then identified. Crops were divided into eight types that include vegetables, fruits, citrus, olives, palms, export crops, field crops and medical and aromat ic crops. The results indicate that the economic criteria are the most important criteria as they represent 0.33 of the total weight, while the technical criteria are the least impo rtant criteria as they represent 0.07 of the total weight. Sub-criteria weights indicate that the contribution to GDP sub-criterion is the most important one with respect to the goal as it has 0.103 of the total weight. Cropping pattern is skewed towards export crops, citrus and vegetables

Emergence of novel methicillin resistant Staphylococcus aureus strains in a tertiary care facility in Tiyadh, Saudi Arabia

Purpose: There is a need for continuous surveillance of methicillin-resistant Staphylococcus aureus (MRSA) to identify emergence of new strains. We hypothesize that MRSA strains are evolving with ongoing acquisition of SCCmec elements. This study was carried out to evaluate the evolution of MRSA at a tertiary care facility in Saudi Arabia. Methods: MRSA isolates associated with invasive clinical infection, which were identified in 2017 at the microbiology laboratory, King Khalid University Hospital (KKUH) in Riyadh, Saudi Arabia, were studied. The molecular characterization of isolates was carried out using StaphyType DNA microarray (Alere Technologies GmbH/Abbott, Jena, Germany). Results: The 125 MRSA isolates studied belonged to 18 clonal complexes (CC) which were distributed into 32 strain assignments. The predominant CC were CC5 (n=30), CC6 (n=17), CC80 (n=13), CC22 (n=12), CC361 (n=12). The findings demonstrated the first identification of CC152, CC361 and CC1153 MRSA as well as ST5-MRSA-[I+fus], “Geraldine Clone”, CC6-MRSA-IV (PVL+) and CC88-MRSA-V (PVL+), WA MRSA-117 in Saudi Arabia. Four novel variants were identified: CC5-MRSA-[VI+fus+tirS], CC22-MRSA-[V/VT+fus](PVL+), CC152-MRSA-[V+fus](PVL+) and CC361-MRSA-[VT+fus]. Fifty-four isolates (n/N=54/125; 43.2%) including the novel strains carried the Q6GD50 SCCfusC gene while the Panton-Valentine leukocidin genes were present in 30.4% (n/N=38/125). Conclusion: The findings demonstrate an expanding MRSA repertoire in our setting including emergence of previously unreported clonal complexes and novel strains. The high carriage of fusC gene suggests a role for fusidic acid misuse in driving the evolution of the MRSA genome and underscores the need for increased monitoring of antibiotic use.Purpose: There is a need for continuous surveillance of methicillin-resistant Staphylococcus aureus (MRSA) to identify emergence of new strains. We hypothesize that MRSA strains are evolving with ongoing acquisition of SCCmec elements. This study was carried out to evaluate the evolution of MRSA at a tertiary care facility in Saudi Arabia. Methods: MRSA isolates associated with invasive clinical infection, which were identified in 2017 at the microbiology laboratory, King Khalid University Hospital (KKUH) in Riyadh, Saudi Arabia, were studied. The molecular characterization of isolates was carried out using StaphyType DNA microarray (Alere Technologies GmbH/Abbott, Jena, Germany). Results: The 125 MRSA isolates studied belonged to 18 clonal complexes (CC) which were distributed into 32 strain assignments. The predominant CC were CC5 (n=30), CC6 (n=17), CC80 (n=13), CC22 (n=12), CC361 (n=12). The findings demonstrated the first identification of CC152, CC361 and CC1153 MRSA as well as ST5-MRSA-[I+fus], “Geraldine Clone”, CC6-MRSA-IV (PVL+) and CC88-MRSA-V (PVL+), WA MRSA-117 in Saudi Arabia. Four novel variants were identified: CC5-MRSA-[VI+fus+tirS], CC22-MRSA-[V/VT+fus](PVL+), CC152-MRSA-[V+fus](PVL+) and CC361-MRSA-[VT+fus]. Fifty-four isolates (n/N=54/125; 43.2%) including the novel strains carried the Q6GD50 SCCfusC gene while the Panton-Valentine leukocidin genes were present in 30.4% (n/N=38/125). Conclusion: The findings demonstrate an expanding MRSA repertoire in our setting including emergence of previously unreported clonal complexes and novel strains. The high carriage of fusC gene suggests a role for fusidic acid misuse in driving the evolution of the MRSA genome and underscores the need for increased monitoring of antibiotic use

Lateral flow immunoassay for the Detection of Panton-Valentine leukocidin in Staphylococcus aureus from skin and soft tissue infections in the United Arab Emirates

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 pvl-positives (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 co-carriage 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