Search results for: dental bacteria
Commenced in January 2007
Frequency: Monthly
Edition: International
Paper Count: 1795

Search results for: dental bacteria

1615 Extracellular Hydrolase-Producing Bacteria Isolated from Chilca Salterns in Peru

Authors: Carol N. Flores-Fernández, Guadalupe Espilco, Cynthia Esquerre, Amparo I. Zavaleta

Abstract:

Saline environments represent a valuable source of enzymes with novel properties and particular features for application in food, pharmaceutical and chemical industry. This study focuses on the isolation and screening of hydrolase-producing bacteria from Chilca salterns and the evaluation of their biotechnological potential. Soil samples were collected from Chilca salterns in Peru. For the isolation, medium containing 0.2 % of yeast extract, 5 % of NaCl and 10 % of the soil sample was used. After 72 h of incubation at 37 °C, serial dilutions were made up to 10−12 dilutions, spread on agar plates with 0.5 % of yeast extract and 5 % of NaCl, and incubated at 37 °C for 48 h. Screening of hydrolase-producing bacteria was carried out for cellulases, amylases, lipases, DNase, and proteases on specific media. Moreover, protease-producing bacteria were tested using protein extracted from the following legumes as substrate: Glycine max, Lupinus mutabilis, Pisum sativum, Erythrina edulis, Cicer arietinum, Phaseolus vulgaris and Vicia faba. A total of 16 strains were isolated from soil samples. On the screening media; 75, 44, 81 and 50 % were cellulase, amylase, DNase and protease producers, respectively. Also, 19 % of the isolates produced all the hydrolytic enzymes above mentioned. Lipase producers were not found. The 37 % and 12 % of the strains grew at 20 % and 30 % of salt concentration, respectively. In addition, 75 % of the strains grew at pH range between 5 and 10. From the total of protease-producing bacteria, 100 % hydrolyzed Glycine max, Lupinus mutabilis, and Pisum sativum protein, while 87 % hydrolyzed Erythrina edulis and Cicer arietinum protein. Finally, 75 % and 50 % of the strains hydrolyzed Phaseolus vulgaris and Vicia faba protein, respectively. Hydrolase-producing bacteria isolated from Chilca salterns in Peru grew at high salt concentrations and wide range of pH. In addition, protease-producing bacteria hydrolyzed protein from different sources such as leguminous. These enzymes have great biotechnological potential and could be used for different industrial processes and applications.

Keywords: bacteria, extracellular, hydrolases, Peru, salterns

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1614 Synthesizing and Fabrication of Pani-(SnO₂, ZnO)/rGO by Sol-Gel Method to Develop a Biosensor Thin-Films on Top Glass Substrate

Authors: Mohammad Arifin, Huda Abdullah, Norshafadzila Mohammad Naim

Abstract:

The fabricated PANI-(SnO₂, ZnO)/rGO nanocomposite thin films for the E. coli bacteria sensor were investigated. The nanocomposite thin films were prepared by the sol-gel method and deposited on the glass substrate using the spin-coating technique. The internal structure and surface morphology of the thin films have been analyzed by X-ray diffraction (XRD), field emission scanning electron microscopy (FESEM), and atomic force microscopy (AFM). The optical properties of the films were investigated by UV-Vis spectroscopy, Raman spectroscopy, and Fourier transform infrared spectroscopy (FTIR). The sensitivity performance was identified by measuring the changing conductivity before and after the incubation of E. coli bacteria using current-voltage (I-V) and cyclic voltammetry (C-V) measurements.

Keywords: PANI-(SnO₂, ZnO)/rGO, nanocomposite, bacteria sensor, thin films

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1613 Analysis of Expert Possibilities While Identifying Human Teeth

Authors: Saule Mussabekova

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Forensic investigation of human teeth plays an important role in detection of crime, particularly in cases of personal identification of dead bodies changed by putrefactive processes or skeletonized bodies as well as when finding bodies of unknown persons. 152 teeth have been investigated; 85 of them belonged to men and 67 belonged to women taken from alive people of different age. Teeth have been investigated after extraction. Two types of teeth have been investigated: teeth without integrity violation of dental crown and teeth with different degrees of its violation. Additionally, 517 teeth have been investigated that were collected from dead bodies, 252 of which belonged to women and 265 belonged to men, whatever the cause of death with death limitation from 1 month to 20 years. Isohemagglutinating serums and Coliclons of different series have been used for the research of tooth-group specificity by serological methods according to the AB0 system. Standard protocols of different techniques have been used for DNA purification from teeth (by reagent Chelex 100 produced by Bio-Rad using reagent kit 'DNA IQTM System' produced by Promega company (USA) and using columns 'QIAamp DNA Investigator Kit' produced by Qiagen company). Results of comparative forensic investigation of human teeth using serological and molecular genetic methods have shown that use of serological methods for forensic identification is sensible only in cases of preselection prior to the next molecular genetic investigation as well as in cases of impossibility of corresponding genetic investigation for different objective reasons. A number of advantages of methods of molecular genetics in the dental investigation have been marked, particularly in putrefactive changes, in personal identification. Key moments of modern condition of personal identification have been reflected according to dental state. Prospective directions of advance preparation of material have been emphasized for identification of teeth in forensic practice.

Keywords: dental state, forensic identification, molecular genetic analysis, teeth

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1612 Oncological and Antiresorptive Treatment of Breast Cancer: Dental Assessment and Risk of MRONJ Development

Authors: Magdalena Korytowska, Gunnar Lengstrand, Cecilia Larsson Wexell

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Background: Breast cancer (BC) is the most common cancer among women worldwide, and cases are continuing to increase in Sweden. Bone is the most common metastatic site in breast cancer patients, where > 65-75% of women with advanced breast cancer develop bone metastases during their disease. To prevent the skeletal-related events of metastases (e.g., pathological fractures, bone loss, cancer-induced bone pain, and hypercalcemia bone), two different classes of antiresorptive medications (AR), bisphosphonate and denosumab are typically administered every 3 to 4 weeks. Since 2015, adjuvant bisphosphonate treatment has been used every six months for three to five years in postmenopausal women for the prevention of skeletal metastases and improved survival. Methods: A case-control study was conducted to test the hypotheses that patients treated with high-dose AR are at higher risk of developing MRONJ than breast cancer patients with adjuvant bisphosphonate treatment at a lower dose. Medical and odontological data was collected between 2015-2020. Assessment of oral health and dental care before and during oncological treatment took place at the specialist clinic for Orofacial medicine linked to the specific hospital. Results: In total, 220 patients were included, 101 patients in the high-dose group and 119 patients in the adjuvant BP-treatment group. MRONJ was diagnosed in 13 patients (14%) in the high-dose group. The mandible was affected in most of the cases (84.6%), with a mean duration of high-dose treatment of 19.7 months. In 46.2% of cases, no dental cause of MRONJ could be identified. Overall, estrogen receptor-positive (ER+) BC was the most representative type in 172 patients (78.2%). However, this was 83.9% in the high-dose cases group. The most used drug was denosumab. Twenty-five patients (26.9%) switched their medication from ZOL to denosumab during their oncological treatment. Patients with ER+ breast cancer were reported in 88 patients (87.8%) in the adjuvant group that was treated with ZOL. Conclusions: MRONJ was diagnosed only in the high-dose AR group. Dental assessment and care of patients in the adjuvant group should be considered, with a recommendation to potentially prolong ZOL treatment from 3 to 5 years, with concomitant use of hormonal therapy in patients diagnosed with ER+ breast cancer to prevent bone loss induced by oncological treatment. A new referral for dental assessment is very important in the case of bone metastases when treatment with high dose AR will be required since it is associated with a higher risk of MRONJ.

Keywords: antiresorptive therapy, breast cancer, dental care, MRONJ

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1611 Multidisciplinary Rehabilitation Algorithm after Mandibular Resection for Ameloblastoma

Authors: Joaquim de Almeida Dultra, Daiana Cristina Pereira Santana, Fátima Karoline Alves Araújo Dultra, Liliane Akemi Kawano Shibasaki, Mariana Machado Mendes de Carvalho, Ieda Margarida Crusoé Rocha Rebello

Abstract:

Defects originating from mandibular resections can cause significant functional impairment and facial disharmony, and they have complex rehabilitation. The aim of this report is to demonstrate the authors' experience facing challenging rehabilitation after mandibular resection in a patient with ameloblastoma. Clinical and surgical steps are described simultaneously, highlighting the adaptation of the final fixed prosthesis, reported in an unprecedented way in the literature. A 37-year-old male patient was seen after a sports accident, where a pathological fracture in the symphysis and left mandibular body was identified, where a large radiolucent lesion was found. The patient underwent resection, bone graft, distraction osteogenesis, rehabilitation with dental implants, prosthesis, and finally, orofacial harmonization, in an interval of six years. Rehabilitation should consider the patient's needs individually and should have as the main objective to provide similar aesthetics and function to that present before the disease. We also emphasize the importance of interdisciplinary work during the course of rehabilitation.

Keywords: ameloblastoma, mandibular reconstruction, distraction osteogenesis, dental implants. dental prosthesis, implant-supported, treatment outcome

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1610 The Use of Microbiological Methods to Reduce Aflatoxin M1 in Cheese

Authors: Bruna Goncalves, Jennifer Henck, Romulo Uliana, Eliana Kamimura, Carlos Oliveira, Carlos Corassin

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Studies have shown evidence of human exposure to aflatoxin M1 due to the consumption of contaminated milk and dairy products (mainly cheeses). This poses a great risk to public health, since milk and milk products are frequently consumed by a portion of the population considered immunosuppressed, children and the elderly. Knowledge of the negative impacts of aflatoxins on health and economics has led to investigations of strategies to prevent their formation in food, as well as to eliminate, inactivate or reduce the bioavailability of these toxins in contaminated products This study evaluated the effect of microbiological methods using lactic acid bacteria on aflatoxin M1 (AFM1) reduction in Minas Frescal cheese (typical Brazilian product, being among the most consumed cheeses in Brazil) spiked with 1 µg/L AFM1. Inactivated lactic acid bacteria (0,5%, v/v de L. rhamnosus e L. lactis) were added during the cheese production process. Nine cheeses were produced, divided into three treatments: negative controls (without AFM1 or lactic acid bacteria), positive controls (AFM1 only), and lactic acid bacteria + AFM1. Samples of cheese were collected on days 2, 10, 20 and 30 after the date of production and submitted to composition analyses and determination of AFM1 by high-performance liquid chromatography. The reductions of AFM1 in cheese by lactic acid bacteria at the end of the trial indicate a potential application of inactivated lactic acid bacteria in reducing the bioavailability of AFM1 in Minas frescal cheese without physical-chemical and microbiological modifications during the 30-day experimental period. The authors would like to thank São Paulo Research Foundation – FAPESP (grants #2017/20081-6 and #2017/19683-1).

Keywords: aflatoxin, milk, minas frescal cheese, decontamination

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1609 Isolation and Identification of the Dominant Flora of the Intestinal Microbiota of Rattus norvegicus an Algerian Firm West

Authors: Karima Ould Yerou, B. Meddah, A. Tir Touil

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The intestinal flora also called the intestinal microbiota, consists of different bacteria and other microorganisms which occur naturally in the gastrointestinal tract organs components. These intestinal bacteria are present in their millions and help the functioning of the body in particular allowing aid to degradation of certain molecules into absorbable substrates. They also protect against invasion of the gut by other pathogenic bacteria, that is to say which may be responsible for disease. Factors like stress, antibiotics and diet can affect the balance of intestinal flora and in case of imbalance, digestive disorders type bloating, diarrhea or vomiting may occur. Rattus norvegicus of bad weight of 100 kg, an Algerian firm West are scarified and isolation of their ileum and colon respectively two Bactrian strains Escherichia coli and Lactobacillus are then purified and identified.

Keywords: intestinal flora, Rattus norvegicus, Escherichia coli, lactobacillus, West Algerian farm

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1608 Microwave Sanitization of Polyester Fabrics

Authors: K. Haggag, M. Salama, H. El-Sayed

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Polyester fabrics were sanitized by exposing them to vaporized water under the influence of conventional heating or microwave irradiation. Hydrogen peroxide was added the humid sanitizing environment as a disinfectant. The said sanitization process was found to be effective towards two types of bacteria, namely Escherichia coli ATCC 2666 (G –ve) and Staphylococcus aureus ATCC 6538 (G +ve). The effect of the sanitization process on some of the inherent properties of polyester fabrics was monitored.

Keywords: polyester, fabric, sanitization, microwave, bacteria

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1607 Development of Antibacterial Surface Based on Bio-Inspired Hierarchical Surface

Authors: M.Ayazi, N. Golshan Ebrahimi

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The development of antibacterial surface has devoted extensive researches and important field due to the growing antimicrobial resistance strains. The superhydrophobic surface has raised attention because of reducing bacteria adhesion in the absence of antibiotic agents. Evaluating the current development antibacterial surface has to be investigating to consider the potential of applying superhydrophobic surface to reduce bacterial adhesion or role of patterned surfaces on it. In this study, we present different samples with bio-inspired hierarchical and microstructures to consider their ability in reducing bacterial adhesion. The structures have inspired from rice-like pattern and lotus-leaf that developed on the polydimethylsiloxane (PDMS) and polypropylene (PP). The results of the attachment behaviors have considered on two bacteria strains of gram-negative Escherichia coli (E. coli) bacteria and gram-positive Staphylococcus aureus (S. aureus). The reduction of bacteria adhesion on these roughness surfaces demonstrated the effectiveness of rinsing ability on removing bacterial cells on structured plastic surfaces. Results have also offered the important role of bacterial species, material chemistry and hierarchical structure to prevent bacterial adhesion.

Keywords: hierarchical structure, self-cleaning, lotus-effect, bactericidal

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1606 Evaluation of Polymerisation Shrinkage of Randomly Oriented Micro-Sized Fibre Reinforced Dental Composites Using Fibre-Bragg Grating Sensors and Their Correlation with Degree of Conversion

Authors: Sonam Behl, Raju, Ginu Rajan, Paul Farrar, B. Gangadhara Prusty

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Reinforcing dental composites with micro-sized fibres can significantly improve the physio-mechanical properties of dental composites. The short fibres can be oriented randomly within dental composites, thus providing quasi-isotropic reinforcing efficiency unlike unidirectional/bidirectional fibre reinforced composites enhancing anisotropic properties. Thus, short fibres reinforced dental composites are getting popular among practitioners. However, despite their popularity, resin-based dental composites are prone to failure on account of shrinkage during photo polymerisation. The shrinkage in the structure may lead to marginal gap formation, causing secondary caries, thus ultimately inducing failure of the restoration. The traditional methods to evaluate polymerisation shrinkage using strain gauges, density-based measurements, dilatometer, or bonded-disk focuses on average value of volumetric shrinkage. Moreover, the results obtained from traditional methods are sensitive to the specimen geometry. The present research aims to evaluate the real-time shrinkage strain at selected locations in the material with the help of optical fibre Bragg grating (FBG) sensors. Due to the miniature size (diameter 250 µm) of FBG sensors, they can be easily embedded into small samples of dental composites. Furthermore, an FBG array into the system can map the real-time shrinkage strain at different regions of the composite. The evaluation of real-time monitoring of shrinkage values may help to optimise the physio-mechanical properties of composites. Previously, FBG sensors have been able to rightfully measure polymerisation strains of anisotropic (unidirectional or bidirectional) reinforced dental composites. However, very limited study exists to establish the validity of FBG based sensors to evaluate volumetric shrinkage for randomly oriented fibres reinforced composites. The present study aims to fill this research gap and is focussed on establishing the usage of FBG based sensors for evaluating the shrinkage of dental composites reinforced with randomly oriented fibres. Three groups of specimens were prepared by mixing the resin (80% UDMA/20% TEGDMA) with 55% of silane treated BaAlSiO₂ particulate fillers or by adding 5% of micro-sized fibres of diameter 5 µm, and length 250/350 µm along with 50% of silane treated BaAlSiO₂ particulate fillers into the resin. For measurement of polymerisation shrinkage strain, an array of three fibre Bragg grating sensors was embedded at a depth of 1 mm into a circular Teflon mould of diameter 15 mm and depth 2 mm. The results obtained are compared with the traditional method for evaluation of the volumetric shrinkage using density-based measurements. Degree of conversion was measured using FTIR spectroscopy (Spotlight 400 FT-IR from PerkinElmer). It is expected that the average polymerisation shrinkage strain values for dental composites reinforced with micro-sized fibres can directly correlate with the measured degree of conversion values, implying that more C=C double bond conversion to C-C single bond values also leads to higher shrinkage strain within the composite. Moreover, it could be established the photonics approach could help assess the shrinkage at any point of interest in the material, suggesting that fibre-Bragg grating sensors are a suitable means for measuring real-time polymerisation shrinkage strain for randomly fibre reinforced dental composites as well.

Keywords: dental composite, glass fibre, polymerisation shrinkage strain, fibre-Bragg grating sensors

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1605 Effect of Fiddler Crab Burrows on Bacterial Communities of Mangrove Sediments

Authors: Mohammad Mokhtari, Gires Usup, Zaidi Che Cob

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Bacteria communities as mediators of the biogeochemical process are the main component of the mangrove ecosystems. Crab burrows by increasing oxic-anoxic interfaces and facilitating the flux rate between sediment and tidal water affect biogeochemical properties of sediments. The effect of fiddler crab burrows on the density and diversity of bacteria were investigated to elucidate the effect of burrow on bacterial distribution. Samples collected from the burrow walls of three species of fiddler crabs including Uca paradussumieri, Uca rosea, and Uca forcipata. Sediment properties including grain size, temperature, Redox potential, pH, chlorophyll, water and organic content were measured from the burrow walls to assess the correlation between environmental variables and bacterial communities. Bacteria were enumerated with epifluorescence microscopy after staining with SYBR green. Bacterial DNA extracted from sediment samples and the community profiles of bacteria were determined with Terminal Restriction Fragment Length Polymorphism (T-RFLP). High endemism was observed among bacterial communities. Among the 152 observed OTU’s, 22 were found only in crab burrows. The highest bacterial density and diversity were recorded in burrow wall. The results of ANOSIM indicated a significant difference between the bacterial communities from the three species of fiddler crab burrows. Only 3% of explained bacteria variability in the constrained ordination model of CCA was contributed to depth, while much of the bacteria’s variability was attributed to coarse sand, pH, and chlorophyll content. Our findings suggest that crab burrows by affecting sediment properties such as redox potential, pH, water, and chlorophyll content induce significant effects on the bacterial communities.

Keywords: bioturbation, canonical corresponding analysis, fiddler crab, microbial ecology

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1604 One Health Approach: The Importance of Improving the Identification of Waterborne Bacteria in Austrian Water

Authors: Aurora Gitto, Philipp Proksch

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The presence of various microorganisms (bacteria, fungi) in surface water and groundwater represents an important issue for human health worldwide. The matrix-assisted laser desorption/ionization-time of flight mass spectrometry (MALDI-TOF-MS) has emerged as a promising and reliable tool for bacteria identification in clinical diagnostic microbiology and environmental strains thanks to an ionization technique that uses a laser energy absorbing matrix to create ions from large molecules with minimal fragmentation. The study aims first to conceptualise and set up library information and create a comprehensive database of MALDI-TOF-MS spectra from environmental water samples. The samples were analysed over a year (2021-2022) using membrane filtration methodology (0.45 μm and 0.22 μm) and then isolated on R2A agar for a period of 5 days and Yeast extract agar growing at 22 °C up to 4 days and 37 °C for 48 hours. The undetected organisms by MALDI-TOF-MS were analysed by PCR and then sequenced. The information obtained by the sequencing was further implemented in the MALDI-TOF-MS library. Among the culturable bacteria, the results show how the incubator temperature affects the growth of some genera instead of others, as demonstrated by Pseudomonas sp., which grows at 22 °C, compared to Bacillus sp., which is abundant at 37 °C. The bacteria community shows a variation in composition also between the media used, as demonstrated with R2A agar which has been defined by a higher presence of organisms not detected compared to YEA. Interesting is the variability of the Genus over one year of sampling and how the seasonality impacts the bacteria community; in fact, in some sampling locations, we observed how the composition changed, moving from winter to spring and summer. In conclusion, the bacteria community in groundwater and river bank filtration represents important information that needs to be added to the library to simplify future water quality analysis but mainly to prevent potential risks to human health.

Keywords: water quality, MALDI-TOF-MS, sequencing, library

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1603 Evaluation of Antimicrobial Susceptibility Profile of Urinary Tract Infections in Massoud Medical Laboratory: 2018-2021

Authors: Ali Ghorbanipour

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The aim of this study is to investigate the drug resistance pattern and the value of the MIC (minimum inhibitory concentration)method to reduce the impact of infectious diseases and the slow development of resistance. Method: The study was conducted on clinical specimens collected between 2018 to 2021. identification of isolates and antibiotic susceptibility testing were performed using conventional biochemical tests. Antibiotic resistance was determined using kibry-Bauer disk diffusion and MIC by E-test methods comparative with microdilution plate elisa method. Results were interpreted according to CLSI. Results: Out of 249600 different clinical specimens, 18720 different pathogenic bacteria by overall detection ratio 7.7% were detected. Among pathogen bacterial were Gram negative bacteria (70%,n=13000) and Gram positive bacteria(30%,n=5720).Medically relevant gram-negative bacteria include a multitude of species such as E.coli , Klebsiella .spp , Pseudomonas .aeroginosa , Acinetobacter .spp , Enterobacterspp ,and gram positive bacteria Staphylococcus.spp , Enterococcus .spp , Streptococcus .spp was isolated . Conclusion: Our results highlighted that the resistance ratio among Gram Negative bacteria and Gram positive bacteria with different infection is high it suggest constant screening and follow-up programs for the detection of antibiotic resistance and the value of MIC drug susceptibility reporting that provide a new way to the usage of resistant antibiotic in combination with other antibiotics or accurate weight of antibiotics that inhibit or kill bacteria. Evaluation of wrong medication in the expansion of resistance and side effects of over usage antibiotics are goals. Ali ghorbanipour presently working as a supervision at the microbiology department of Massoud medical laboratory. Iran. Earlier, he worked as head department of pulmonary infection in firoozgarhospital, Iran. He received master degree in 2012 from Fergusson College. His research prime objective is a biologic wound dressing .to his credit, he has Published10 articles in various international congresses by presenting posters.

Keywords: antimicrobial profile, MIC & MBC Method, microplate antimicrobial assay, E-test

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1602 Entomopathogenic Bacteria as Biological Control Agents: Review Paper

Authors: Tadesse Kebede Dabsu

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Insect pest is one the major limiting factor for sustainable food production. To overtake insect pest problem, since Second World War, producers have used excessive insecticide for insect pest management. However, in the era of 21st Century, the excessive use of insecticide caused insect resistant, insecticide bioaccumulation, insecticide hazard to environment, human health problem, and the like. Due to these problems, research efforts have been focused on the development of environmental free sustainable insect pest management method. To minimize all above mentioned risk utilizing of biological control such as entomopathogenicmicroorganism include bacteria, virus, fungus, and their productsare the best option for suppress insect population below certain density level. The objective of this review was to review the updated available studies and recent developments on the entomopathogenic bacteria (EPB) as biological control of insect pest and challenge of using them for control of insect pest. EPB’s mechanisms of insecticidal activities, type, taxonomy, and history are included in this paper body. EPB has been successfully used for the suppression of populations of insect pests. Controlling of harmful insect by entomopathogenic bacteria is an effective, low bioaccumulation in environment and food, very specific, reduce resistance risk in insect pest, economically and sustainable method of major insect pest management method. Identified and reported as potential major common type of entomopathogenic bacteria include Bacillus thuringiensis, Photorhabdus sp., Xenorhabdus spp.Walbachiaspp, Actinomycetesspp.etc. These bacteria being enter into insect body through natural opening or by vector release toxin protein inside of insect and disrupt the cell’s content cause natural mortality under natural condition. As per reported by different scientists, insect orders like Lepidoptera, Hemiptera, Hymenoptera, Coleoptera, and Dipterahave been successful controlled by entomopathogenic bacteria. As per coming across in different scientific research journals, much of the work was emphasised on Bacillus thuringiensisbsp. Therefore, for commercial production like Bacillus thuringiensi, detail research should be done on other bacteria species. The efficacy and practical application of EPB are restricted to some crops and greenhouse area, but their field application at farmers’ level very less. So still much work needs to be done to the practical application of the EPB at widely application. Their efficacy, pathogenicity, and host range test should be tested under environmental condition.

Keywords: insect pest, entomopathogenic bacteria, biological control, agent

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1601 Preparation and Fabrication of Lithium Disilicate Glass Ceramic as Dental Crowns via Hot Pressing Method

Authors: A. Srion, W. Thepsuwan, N. Monmaturapoj

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Two Lithium disilicate (LD) glass ceramics based on SiO2-Li2O-K2O-Al2O3 system were prepared through glass melting method and then fabricated into dental crowns via hot pressing at 850˚C and 900˚C in order to study the effect of the pressing temperatures on theirs phase formation and microstructure. The factor such as heat treatment temperature (as-cast glass, 600˚C and 700˚C) of the glass ceramics used to press was also investigated the effect of an initial microstructure before pressing. X-ray diffraction (XRD) and scanning electron microscopy (SEM) were used to determine phase formation and microstructure of the samples, respectively. X-ray diffraction result shows that the main crystalline structure was Li2Si2O5 by having Li3PO4, Li0.6Al0.6Si2O6, Li2SiO3, Ca5 (PO4)3F, SiO2 as minor phases. Glass compositions with different heat treatment temperatures exhibited a difference phase formation but have less effect during pressing. Scanning electron microscopy analysis showed microstructure of lath-like of Li2Si2O5 in all glasses. With increasing the initial heat treatment temperature, the longer the lath-like crystals of lithium disilicate were increased especially when using glass heat treatment at 700˚C followed by pressing at 900˚C. This could be suggested that LD1 heat treatment at 700˚C which pressing at 900˚C presented the best formation by hot pressing and compiled microstructure.

Keywords: lithium disilicate, hot pressing, dental crown, microstructure

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1600 Length of Pregnancy and Dental Caries Observation in Relation to BMI

Authors: Edit Xhajanka, Gresa Baboci, Irene Malagnino, Mimoza Canga, Vito Antonio Malagnino

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Purpose: This study aimed at identifying dental caries increment or reduction, based on factors such as smoking, the scaling of teeth, BMI before and during pregnancy, carbohydrates consumption in relation to childbirth. Material and method: In this observational study, the sample included a total of 98 pregnant women and their age class was 18-45 years old, with a median age of 31.5 years. The setting of the participants resides in Vlora –Albania. Moreover, 64.4% were from the city and 35.6% were from the nearby villages. The study was conducted in the time period January 2018 –June 2021. Body mass index (BMI) was calculated using the standard formula (kg/m²). Maternal pre, during and post-pregnancy BMI was collected by using a validated questionnaire. Statistical analysis was performed using IBM SPSS Statistics 23.0. The significance level (α) was set at 0.05, whereas P-value and analysis of variance (ANOVA) were used to analyze the data. Results: Based on the data analysis, 44.4% of the sample declared that they did smoke before pregnancy and 55.6% not smoked during their pregnancy. As a result, no association was found between smoking and length of pregnancy P=0.95. There is also a strong relation (P=0.000) between the number of teeth with caries before pregnancy and the number of teeth with caries during pregnancy. There is a significant relationship between the scaling of teeth and childbirth, P=0.05. BMI before and during pregnancy in relation to carbohydrates consumption have a significant correlation P=0.004 and P=0.002. The values of BMI before and during pregnancy in relation to childbirth have a strong correlation: P=0.043 and P=0.040, respectively. As a result, obesity was associated with preterm birth. The percentage of children born during 34-36 weeks of pregnancy was 69%, and children born during 32-34 weeks of pregnancy were 31%. CONCLUSION: There was a positive association between dental caries experience, BMI and carbohydrates consumption. Obesity in pregnancy is increasing worldwide; that is why this study suggests the importance of an appropriate weight before and during pregnancy.

Keywords: BMI, dental caries, pregnancy, scaling, smoking

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1599 Production and Characterization of Silver Doped Hydroxyapatite Thin Films for Biomedical Applications

Authors: C. L Popa, C.S. Ciobanu, S. L. Iconaru, P. Chapon, A. Costescu, P. Le Coustumer, D. Predoi

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In this paper, the preparation and characterization of silver doped hydroxyapatite thin films and their antimicrobial activity characterized is reported. The resultant Ag: HAp films coated on commercially pure Si disks substrates were systematically characterized by Scanning Electron Microscopy (SEM) coupled with X-ray Energy Dispersive Spectroscopy detector (X-EDS), Glow Discharge Optical Emission Spectroscopy (GDOES) and Fourier Transform Infrared spectroscopy (FT-IR). GDOES measurements show that a substantial Ag content has been deposited in the films. The X-EDS and GDOES spectra revealed the presence of a material composed mainly of phosphate, calcium, oxygen, hydrogen and silver. The antimicrobial efficiency of Ag:HAp thin films against Escherichia coli and Staphylococcus aureus bacteria was demonstrated. Ag:HAp thin films could lead to a decrease of infections especially in the case of bone and dental implants by surface modification of implantable medical devices.

Keywords: silver, hydroxyapatite, thin films, GDOES, SEM, FTIR, antimicrobial effect

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1598 Depyritization of US Coal Using Iron-Oxidizing Bacteria: Batch Stirred Reactor Study

Authors: Ashish Pathak, Dong-Jin Kim, Haragobinda Srichandan, Byoung-Gon Kim

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Microbial depyritization of coal using chemoautotrophic bacteria is gaining acceptance as an efficient and eco-friendly technique. The process uses the metabolic activity of chemoautotrophic bacteria in removing sulfur and pyrite from the coal. The aim of the present study was to investigate the potential of Acidithiobacillus ferrooxidans in removing the pyritic sulfur and iron from high iron and sulfur containing US coal. The experiment was undertaken in 8 L bench scale stirred tank reactor having 1% (w/v) pulp density of coal. The reactor was operated at 35ºC and aerobic conditions were maintained by sparging the air into the reactor. It was found that at the end of bio-depyritization process, about 90% of pyrite and 67% of pyritic sulfur was removed from the coal. The results indicate that the bio-depyritization process is an efficient process in treating the high pyrite and sulfur containing coal.

Keywords: At.ferrooxidans, batch reactor, coal desulfurization, pyrite

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1597 Epiphytic Growth on Filamentous Bacteria Found in Activated Sludge: A Morphological Approach

Authors: Thobela Conco, Sheena Kumari, Thor Stenstrom, Simona Rosetti, Valter Tandoi, Faizal Bux

Abstract:

Filamentous bacteria are well documented as causative agents of bulking and foaming in the biological wastewater treatment process. These filamentous bacteria are however closely associated with other non-filamentous organism forming a micro-niche. Among these specific epiphytic bacteria attach to filaments in the consortium of organisms that make up the floc. Neither the eco-physiological role of the epiphytes nor the nature of the interaction between the epiphytic bacteria and the filament hosts they colonize is well understood and in need of in-depth investigations. The focus of this presentation is on the interaction between the epiphytic bacteria and the filament host. Samples from the activated sludge treatment have been repeatedly collected from several wastewater treatment plants in KwaZulu Natal. Extensive investigations have been performed with SEM and TEM electron microscopy, Polarized Light Microscopy with Congo red staining, and Thioflavin T staining to document the interaction. SEM was used to document the morphology of both the filament host and their epiphytes counterparts with the focus on the interface/point of contact between the two, while the main focus of the TEM investigations with the higher magnification aimed to document the ultra-structure features of two organisms relating to the interaction. The interaction of the perpendicular attachment partly seems to be governed by the physiological status of the filaments. The attachment further seems to trigger a response in the filaments with distinct internal visible structures at the attachment sites. It is postulated that these structures most likely are amyloid fibrils. Amyloid fibrils may play an overarching role in different types of attachments and has earlier been noted to play a significant role in biofilm formation in activated sludge. They also play a medical role in degenerative diseases such as Alzheimer’s and Diabetes. Further studies aims to define the eco-physiological role of amyloid fibrils in filamentous bacteria, based on their observed presence at interaction sites in this study. This will also relate to additional findings where selectivity within the species of epiphytes attaching to the selected filaments has been noted. The practical implications of the research findings is still to be determined, but the ecophysiological interaction between two closely associated species or groups may have significant impact in the future understanding of wastewater treatment processes and broaden existing knowledge on population dynamics.

Keywords: activated sludge, amyloid proteins, epiphytic bacteria, filamentous bacteria

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1596 Preparation and Removal Properties of Hollow Fiber Membranes for Drinking Water

Authors: Seung Moon Woo, Youn Suk Chung, Sang Yong Nam

Abstract:

In the present time, we need advanced water treatment technology for separation of virus and bacteria in effluent which occur epidemic and waterborne diseases. Water purification system is mainly divided into two categorizations like reverse osmosis (RO) and ultrafiltration (UF). Membrane used in these systems requires higher durability because of operating in harsh condition. Of these, the membrane using in UF system has many advantages like higher efficiency and lower energy consume for water treatment compared with RO system. In many kinds of membrane, hollow fiber type membrane is possible to make easily and to get optimized property by control of various spinning conditions such as temperature of coagulation bath, concentration of polymer, addition of additive, air gap and internal coagulation. In this study, polysulfone hollow fiber membrane was successfully prepared by phase inversion method for separation of virus and bacteria. When we prepare the hollow fiber membrane, we controlled various factors such as the polymer concentration, air gap and internal coagulation to investigate effect to membrane property. Morphology of surface and cross section of membrane were measured by field emission scanning electron microscope (FE-SEM). Water flux of membrane was measured using test modules. Mean pore diameter of membrane was calculated using rejection of polystyrene (PS) latex beads for separation of virus and bacteria. Flux and mean flow pore diameter of prepared membrane show 1.5 LPM, 0.03 μm at 1.0 kgf/cm2. The bacteria and virus removal performance of prepared UF membranes were over 6 logs.

Keywords: hollow fiber membrane, drinking water, ultrafiltration, bacteria

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1595 A Bacterial Foraging Optimization Algorithm Applied to the Synthesis of Polyacrylamide Hydrogels

Authors: Florin Leon, Silvia Curteanu

Abstract:

The Bacterial Foraging Optimization (BFO) algorithm is inspired by the behavior of bacteria such as Escherichia coli or Myxococcus xanthus when searching for food, more precisely the chemotaxis behavior. Bacteria perceive chemical gradients in the environment, such as nutrients, and also other individual bacteria, and move toward or in the opposite direction to those signals. The application example considered as a case study consists in establishing the dependency between the reaction yield of hydrogels based on polyacrylamide and the working conditions such as time, temperature, monomer, initiator, crosslinking agent and inclusion polymer concentrations, as well as type of the polymer added. This process is modeled with a neural network which is included in an optimization procedure based on BFO. An experimental study of BFO parameters is performed. The results show that the algorithm is quite robust and can obtain good results for diverse combinations of parameter values.

Keywords: bacterial foraging, hydrogels, modeling and optimization, neural networks

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1594 One Way to Address the Complications of Dental Implantology

Authors: Predrag Kavaric, Vladimir L. Jubic, Maxim Cadenovic

Abstract:

The patient was transferred from his dentist to our tertiary medical institution. In anamnesis, we got information that his dental intervention was two years ago when he got dental implants but because of the coronavirus pandemic event, he didn’t finish the whole procedure. After two years, he decided that he will continue his work at his dentist, then his dentist noticed that there is no earlier inserted implant in the upper jaw on the right side. They do Panoramic X-ray and find that the implant is all in the maxillary sinus cavity. The flour of the maxilla was intact without any fistula on the place where the implant was inserted in the maxilla bone, After that initial diagnostic they sent the patient to maxillofacial surgery and otorhinolaryngology. We asked for a CT scan of paranasal sinuses, which confirmed the foreign body in the right maxillary sinus. The plan was that in general anesthesia we do FESS and try to find a foreign body in the maxillary sinus or in case of failure to do Caldwel Luc on that side. After preoperative preparation in GA, we do FESS. In inspection, we find small polyps and chronically changed mucosa of osteomeatal complex and right maxillary sinus. After removing polyps we did uncinectomy and medial maxillectomy. With Heuweiser Antrum grasping forceps after several attempts we managed to extract a foreign body from the bottom of the right maxillary sinus. On the first postoperative day we did detamponade, and then we discharge the patient from hospital. The Covid pandemic has contributed to the postponement of a large number of planned operations, which has resulted in various complications in the treatment of a number of patients. In this case, it happened that the implant was most likely rejected by the bone but in the direction of the maxillary sinus, which is not a common cause. On the other hand, the success was that less traumatic intervention was able to remove the foreign body from the maxillary sinus in which it was located. Since the sinus floor is free of bone defects, it can be continued relatively quickly with dental procedures.

Keywords: x-ray, surgery, maxillar sinus, complication, fees

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1593 Alterations in the Abundance of Ruminal Microbial Species during the Peripartal Period in Dairy Cows

Authors: S. Alqarni, J. C. McCann, A. Palladino, J. J. Loor

Abstract:

Seven fistulated Holstein cows were used from 3 weeks prepartum to 4 weeks postpartum to determine the relative abundance of 7 different species of ruminal microorganisms. The prepartum diet was based on corn silage. In the postpartum, diet included ground corn, grain by-products, and alfalfa haylage. Ruminal digesta were collected at five times: -14, -7, 10, 20, and 28 days around parturition. Total DNA from ruminal digesta was isolated and real-time quantitative PCR was used to determine the relative abundance of bacterial species. Eubacterium ruminantium and Selenomonas ruminantium were not affected by time (P>0.05). Megasphaera elsdenii and Prevotella bryantii increased significantly postpartum (P<0.001). Conversely, Butyrivibrio proteoclasticus decreased gradually from -14 through 28 days (P<0.001). Fibrobacter succinogenes was affected by time being lowest at day 10 (P=0.02) while Anaerovibrio lipolytica recorded the lowest abundance at -7 d followed by an increase by 20 days postpartum (P<0.001). Overall, these results indicate that changes in diet after parturition affect the abundance of ruminal bacteria, particularly M. elsdenii (a lactate-utilizing bacteria) and P. bryantii (a starch-degrading bacteria) which increased markedly after parturition likely as a consequence of a higher concentrate intake.

Keywords: rumen bacteria, transition cows, rumen metabolism, peripartal period

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1592 An Unusual Case of Extensive, Unilateral, Idiopathic Dental Resorption

Authors: Ceri McIntosh

Abstract:

A 25-year-old male was referred to the Maxillofacial department by his general dental practitioner with a complaint of mobile teeth. Medically he was well though he took mirtazapine for anxiety. He was found to have had previous extractions of the lower right second premolar and first molar, with grade 2 mobility of the upper right first and second molars and lower right lateral incisor. Radiographically there was significant external root resorption of these teeth, which were subsequently extracted. Over the next 18 months, the resorption continued around multiple teeth on the right side, and when the mobile teeth were removed, they showed no remaining root, including loss of coronal dentine, leaving only an enamel shell. No cause has been identified either histologically or in the patient’s blood work. A review of relevant literature will be included in this case report.

Keywords: case report, idiopathic resorption, idiopathic root resorption, external resorption

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1591 Development of Gold Nanoparticles-Antibody System for the Selective Photothermal Destruction of Multidrug Resistant Bacteria

Authors: Teodora Mocan, Lucian Mocan, Cornel Iancu, Flaviu A. Tabaran, Bartos Dana, Matea Cristian

Abstract:

Antimicrobial resistance, which threatens the efficacy of the existing antibiotics represents a worldwide public health issue. At the current time, vancomycin is the only responsive treatment although has significant cytotoxicity, is partially effective and it is poorly retained by infected tissues. From a clinical point of view, attractive alternative approaches for treating such Meticillin-Resistant Staphylococcus Aureus (MRSA) strains would be using agents that cause physical damage to the bacteria. Modular nanopharmaceuticals systems are being designed to address all of these multifunctional capabilities for the ideal bacterial treatment, with the ability to mix and match appropriate functions. Here we present a novel method of selective laser photothermal ablation of MRSA bacteria mediated by gold nanoparticles bound to PBP antibody against PBP protein located on the MRSA surface.

Keywords: MRSA, laser, nanoparticle, antibody

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1590 Tooth Fractures Following the Placement of Adjacent Dental Implants: A Case Series and a Systematic Review of the Literature

Authors: Eyal Rosen

Abstract:

This study is aimed to report a possible effect of the presence of dental implants on the development of crown or root fractures in adjacent natural teeth. A series of 26 cases of teeth diagnosed with crown or root fractures following the placement of adjacent dental implants is presented. In addition, a comprehensive systematic review of the literature was performed to detect other studies that evaluated this possible complication. The case series analysis revealed that all crown-fractured teeth were non-endodontically treated teeth (n=18), and all root fractured teeth were endodontically treated teeth (n=8). The time from implant loading to the diagnosis of a fracture in an adjacent tooth was longer than 1 year in 78% of cases. The majority of crown or root fractures occurred in female patients, over 50 years of age, with an average age of 59 in the crown fractures group, and 54 in the root fractures group. Most of the patients received 2 or more implants. Nine (50%) of the teeth with crown fracture were molars, 7 (39%) were mandibular premolars, and 2 (11%) were incisor teeth. The majority of teeth with root fracture were premolar or mandibular molar teeth (6 (75%)). The systematic review of the literature did not reveal additional studies that reported on this possible complication. To the best of the author’s knowledge this case series, although limited in its extent, is the first clinical report of a possible serious complication of implants, associated fractures in adjacent endodontically and non-endodontically treated natural teeth. The most common patient profile found in this series was a woman over 50 years of age, having a fractured premolar tooth, which was diagnosed more than 1 year after reconstruction that was based on multiple adjacent implants. Additional clinical studies are required in order to shed light on this potential serious complication.

Keywords: complications, dental implants, endodontics, fractured teeth

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1589 The Influence of Lactic Acid Bacteria Combinations on Wheat Bread Quality

Authors: Vita Lele, Vadims Bartkevics, Iveta Pugajeva, Paulina Zavistanaviciute, Daiva Zadeike, Grazina Juodeikiene, Elena Bartkiene

Abstract:

Different combinations of appropriate technological properties showing lactic acid bacteria (Pediococcus pentosaceus VLGL183 and Enterococcus pseudoavium VLGL 234, Lactobacillus plantarum VLGL135 and Pediococcus pentosaceus VLGL183, Pediococcus pentosaceus VLGL183 and Lactobacillus brevis VLGL173, Pediococcus pentosaceus VLGL183 and Leuconostoc mesenteroides VLGL242, Pediococcus pentosaceus VLGL183 and Lactobacillus curvatus VLGL51, Lactobacillus plantarum VLGL135 and Lactobacillus curvatus VLGL51) for wheat sourdough production were used, and the influence of different sourdoughs on wheat bread quality parameters was evaluated. The highest overall acceptability (135.8 mm in 140 mm hedonic scale) of the bread produced with L. plantarum VLGL135 and P. pentosaceus VLGL183 sourdough was established. Also, bread produced with above mention sourdough, has the highest specific volume, shape coefficient, moisture content, and porosity, 3.40 ml /g; 2.59, 33.7 %, and 76.6 %, respectively. It was found, that the used sourdoughs reduce acrylamide content in bread (from 29.5 to 67.2%), just, the isolated lactic acid bacteria strains could be recommended for higher quality and safer bread production.

Keywords: acrylamide, lactic acid bacteria, quality, sourdough, wheat bread

Procedia PDF Downloads 153
1588 Analysis of Probiotic Properties of Lactobacillus Acidophilus from Commercial Yoghurt

Authors: Anwar Ali Abdulla, Thekra Abdulaali Abed Al-Chaabawi, Anwar Kadhim Al-Saffar, Hussein Kadhim Al-Saffar

Abstract:

Lactic acid bacteria are very significant to human health due to the production of some antimicrobial substances and ability to inhibit pathogenic bacteria. Furthermore, the bacteria are also used as starter culture in the production of various foods. The present study was focused on isolation and characterization of Lactobacillus acidophilus from yogurt and to demonstrate some of probiotic properties of these isolates. All isolates were phenotypically characterized including studying, biochemical, effect of sodium chloride and pH during growth, carbohydrates test and characterizing the antimicrobial activity of Lactobacillus acidophilus against pathogens. The present study demonstrates that Lactobacillus acidophilus produced a bacteriocin- like inhibitory substance with a broad spectrum of antimicrobial activity directed against pathogenic indicator organism suggesting its protective value against enteric pathogens.

Keywords: lactobacillus acidophilus, bacteriocin, antimicrobial activity, probiotic

Procedia PDF Downloads 507
1587 MR-Implantology: Exploring the Use for Mixed Reality in Dentistry Education

Authors: Areej R. Banjar, Abraham G. Campbell

Abstract:

The use of Mixed Reality (MR) in teaching and training is growing popular and can improve students’ ability to perform technical procedures. This short paper outlines the creation of an interactive educational MR 3D application that aims to improve the quality of instruction for dentistry students. This application is called MRImplantology and aims to teach the fundamentals and preoperative planning of dental implant placement. MRImplantology uses cone-beam computed tomography (CBCT) images as the source for 3D dental models that dentistry students will be able to freely manipulate within a 3D MR world to aid their learning process.

Keywords: augmented reality, education, dentistry, cone-beam computed tomography CBCT, head mounted display HMD, mixed reality

Procedia PDF Downloads 159
1586 Sema4D/Plexin-B1 Signaling Regulates Osteo/Odontogenic Differentiation of Dental Pulp Stem Cells

Authors: Ting Zou, Chengfei Zhang

Abstract:

Objectives: The purpose of this study was to investigate the role of Semaphorin 4D (Sema4D)/Plexin-B1 signaling on osteo/odontogenic differentiation of human dental pulp stem cells (DPSCs) and uncover its molecular mechanism. Methods: DPSCs were cultured in osteo/odontogenic medium. After treatment with Sema4D (10μg/mL), osteo/odontogenic differentiation and mineralization was evaluated by measuring alkaline phosphatase (ALP) activity and alizarin red S staining respectively. The expression of osteo/odontogenic genes (ALP, Col1A1, BSP, and Runx2) was determined by real-time polymerase chain reaction. p-Plexin-B1, Plexin-B1, Col1A1, RhoA, and ErbB2 were analyzed by western. Results: ALP activity and mineralization formation of DPSCs were significantly decreased after treatment with Sema4D (P<0.05). Sema4D significantly down-regulated osteo/odontogenic-related genes expression (ALP, Col1A1, BSP, and Runx2). p-Plexin-B1, Plexin-B1 and RhoA protein expression levels increased after stimulated with Sema4D, while the expression of Col1A1 decreased. Pretreatment with Plexin-B1 antibody blocked Sema4D induced p-Plexin-B1 expression. Conclusion: Sema4D suppressed osteo/odontogenic differentiation of DPSCs via RhoA-mediated pathways.

Keywords: Sema4D/Plexin-B1, dental pulp stem cells, osteo/odontogenic differentiation, alkaline phosphatase (ALP)

Procedia PDF Downloads 230