Microbiological contamination of dental unit water systems in general practices from Barcelona (Spain)

2004 ◽  
Vol 4 (2) ◽  
pp. 1-5 ◽  
Author(s):  
R. Araujo ◽  
N. Contreras
Keyword(s):  
Hard Water ◽  
Water Systems ◽  
Microbial Pathogens ◽  
Microbial Load ◽  
Oral Streptococci ◽  
Candida Sp ◽  
Microbial Biofilms ◽  
Colony Forming Units ◽  
General Practices ◽  
Evidence Based Guidelines

Dental Unit Water Systems (DUWS) can be a source of contamination to dentists and patients, especially those who are immunocompromised. Such organisms may originate from incoming water supplies and from oral cavities. The most common cause of dental unit water contamination is believed to be the formation and subsequent sloughing off of microbial biofilms from tubing within DUWS. There are no evidence-based guidelines currently available to dentists for the control of DUWS contamination in Europe. The aim of this study was to investigate the microbial load of water from DUWS, especially the presence of microbial pathogens which can be a source of cross-contamination between patients. Water and tube samples were obtained from 40 dental surgeries in Barcelona. The samples were taken from turbine and from air/water syringe. Twelve of these DUWS were fed with hard water from mains (with chlorine) and 28 dental units with bottle or tank deionized water. Microbial load was ranged from 0 to 3.6 × 103 colony-forming units/mL. Legionella sp., Mycobacterium sp., Pseudomonas aeruginosa and Candida sp. were found in 4, 8, 6, and 2 different surgeries, respectively. Inclusive oral streptococci were found in 2 dental units indicating that there is a back siphonage in the systems analysed.

Influence of Resin Monomers on Growth of Oral Streptococci

2004 ◽  
Vol 83 (4) ◽  
pp. 302-306 ◽  
Author(s):  
Y. Takahashi ◽  
S. Imazato ◽  
R.R.B. Russell ◽  
Y. Noiri ◽  
S. Ebisu
Keyword(s):  
Morphological Observation ◽  
Bacterial Suspension ◽  
Bacterial Cells ◽  
Oral Streptococci ◽  
Streptococcus Sobrinus ◽  
Associated Bacteria ◽  
Streptococcus Sanguis ◽  
Colony Forming Units ◽  
Biomass Increase

Ethyleneglycol dimethacrylate monomers have been previously reported to stimulate the growth of certain caries-associated bacteria on the basis of turbidity measurements. To elucidate the detail of this effect, we examined the influence of resin monomers on the growth of Streptococcus sobrinus and Streptococcus sanguis by determination of bacterial numbers (colony-forming units), morphological observation, and chemical analysis. Although the absorbance values in the stationary phase of bacterial suspension were increased in the presence of ethyleneglycol monomers, no significant differences were observed for bacterial numbers throughout the incubation period. Scanning electron microscopy observation revealed the formation of sparse vesicular material surrounding bacterial cells when incubated with ethyleneglycol monomers, and these products were proved to be resin polymers. The results demonstrate that the apparent biomass increase during incubation with ethyleneglycol monomers is due not to promotion of bacterial multiplication, but to the polymerization of resin monomers to form vesicular structures attached to cells.

scholarly journals Surface Wiping Test to Study Biocide -Cinnamaldehyde Combination to Improve Efficiency in Surface Disinfection

2020 ◽  
Vol 21 (21) ◽  
pp. 7852
Author(s):  
Joana F. Malheiro ◽  
Catarina Oliveira ◽  
Fernando Cagide ◽  
Fernanda Borges ◽  
Manuel Simões ◽  
...  
Keyword(s):  
Cetyltrimethylammonium Bromide ◽  
Bacterial Resistance ◽  
Mechanical Action ◽  
Microbial Pathogens ◽  
Health Impacts ◽  
Cross Resistance ◽  
Efficacy Evaluation ◽  
Surface Disinfection ◽  
E Coli ◽  
Colony Forming Units

Disinfection is crucial to control and prevent microbial pathogens on surfaces. Nonetheless, disinfectants misuse in routine disinfection has increased the concern on their impact on bacterial resistance and cross-resistance. This work aims to develop a formulation for surface disinfection based on the combination of a natural product, cinnamaldehyde, and a widely used biocide, cetyltrimethylammonium bromide. The wiping method was based on the Wiperator test (ASTM E2967−15) and the efficacy evaluation of surface disinfection wipes test (EN 16615:2015). After formulation optimization, the wiping of a contaminated surface with 6.24 log10 colony-forming units (CFU) of Escherichia coli or 7.10 log10 CFU of Staphylococcus aureus led to a reduction of 4.35 log10 CFU and 4.27 log10 CFU when the wipe was impregnated with the formulation in comparison with 2.45 log10 CFU and 1.50 log10 CFU as a result of mechanical action only for E. coli and S. aureus, respectively. Furthermore, the formulation prevented the transfer of bacteria to clean surfaces. The work presented highlights the potential of a combinatorial approach of a classic biocide with a phytochemical for the development of disinfectant formulations, with the advantage of reducing the concentration of synthetic biocides, which reduces the potentially negative environmental and public health impacts from their routine use.

scholarly journals Oral streptococci growth on aging and non-aging esthetic restorations after radiotherapy

2010 ◽  
Vol 21 (4) ◽  
pp. 346-350 ◽  
Author(s):  
Adriana D. da Cruz ◽  
Karina Cogo ◽  
Cristiane de C. Bergamaschi ◽  
Frab N. Bóscolo ◽  
Francisco C. Groppo ◽  
...  
Keyword(s):  
Streptococcus Mutans ◽  
Bacterial Biofilm ◽  
Oral Streptococci ◽  
Restorative Material ◽  
Biofilm Growth ◽  
Aged Group ◽  
Dental Resins ◽  
Colony Forming Units ◽  
Therapeutic Doses ◽  
Therapeutic Irradiation

The aim of this study was to examine Streptococcus mutans biofilm growth on both aged and non-aged restorative dental resins, which were submitted to therapeutic irradiation. Sixty-four disks of an esthetic restorative material (Filtek Supreme) were divided into 2 groups: aged group (AG) and a non-aged group (NAG). Each group was subdivided into 4 subgroups: non-irradiated and irradiated with 10Gy, 35Gy, and 70Gy. The biofilms were produced by Streptococcus mutans UA159 growing on both AG and NAG surfaces. The colony-forming units per mL (CFU/mL) were evaluated by the ANOVA and the Tukey LSD tests (α=0.05). AG presented smaller amounts of CFU/mL than the NAG before irradiation and after 10Gy of irradiation (p<0.05). AG irradiated with 35 and 70Gy showed increased amount of bacterial biofilm when compared to non-irradiated and 10Gy-irradiated disks (p<0.05). The exposure to ionizing radiation at therapeutic doses promoted changes in bacterial adherence of aged dental restorative material.

Identifying and Reducing Scaling Problems in Solar Hot Water Systems

2003 ◽  
Vol 125 (1) ◽  
pp. 61-66 ◽  
Author(s):  
Derek K. Baker ◽  
Gary C. Vliet
Keyword(s):  
Heat Exchanger ◽  
Potable Water ◽  
Hard Water ◽  
Water Systems ◽  
Hot Water ◽  
Tank Wall ◽  
Rate Model ◽  
Premature Failure ◽  
Water Side ◽  
Freeze Damage

In areas with hard water, scaling can reduce the reliability of solar hot water (SHW) systems. Common reliability problems associated with scaling are both mechanical (collector freeze damage, clogged passages, premature failure of pumps and valves) and thermal (efficiency degradation). A mechanistic and a mathematical scaling rate model are presented. Results from controlled experiments investigating the affect of key water chemistry and heat transfer parameters on the scaling rate are summarized. The implications of these results for designing SHW systems for scaling environments are discussed. Most importantly, indirect systems where the potable water side of the heat exchanger is integrated into the storage tank wall, such as in a wrap-around heat exchanger, are shown to be the most mechanically and thermally reliable systems for scaling environments. A new version of the software SolScale is discussed, which is intended to aid in the design of SHW systems to reduce scaling related reliability problems.

scholarly journals Legionella pneumophila and Protozoan Hosts: Implications for the Control of Hospital and Potable Water Systems

Pathogens ◽  
2020 ◽  
Vol 9 (4) ◽  
pp. 286 ◽  
Author(s):  
Muhammad Atif Nisar ◽  
Kirstin E. Ross ◽  
Melissa H. Brown ◽  
Richard Bentham ◽  
Harriet Whiley
Keyword(s):  
Legionella Pneumophila ◽  
Distribution Systems ◽  
Water Distribution ◽  
Potable Water ◽  
Water Systems ◽  
Water Disinfection ◽  
Health Concern ◽  
Waterborne Pathogen ◽  
Microbial Biofilms ◽  
Pontiac Fever

Legionella pneumophila is an opportunistic waterborne pathogen of public health concern. It is the causative agent of Legionnaires’ disease (LD) and Pontiac fever and is ubiquitous in manufactured water systems, where protozoan hosts and complex microbial communities provide protection from disinfection procedures. This review collates the literature describing interactions between L. pneumophila and protozoan hosts in hospital and municipal potable water distribution systems. The effectiveness of currently available water disinfection protocols to control L. pneumophila and its protozoan hosts is explored. The studies identified in this systematic literature review demonstrated the failure of common disinfection procedures to achieve long term elimination of L. pneumophila and protozoan hosts from potable water. It has been demonstrated that protozoan hosts facilitate the intracellular replication and packaging of viable L. pneumophila in infectious vesicles; whereas, cyst-forming protozoans provide protection from prolonged environmental stress. Disinfection procedures and protozoan hosts also facilitate biogenesis of viable but non-culturable (VBNC) L. pneumophila which have been shown to be highly resistant to many water disinfection protocols. In conclusion, a better understanding of L. pneumophila-protozoan interactions and the structure of complex microbial biofilms is required for the improved management of L. pneumophila and the prevention of LD.

Identifying and Reducing Scaling Problems in Solar Hot Water Systems

Solar Energy ◽  
2002 ◽  
Author(s):  
Derek K. Baker ◽  
Gary C. Vliet
Keyword(s):  
Heat Exchanger ◽  
Potable Water ◽  
Hard Water ◽  
Water Systems ◽  
Hot Water ◽  
Tank Wall ◽  
Rate Model ◽  
Premature Failure ◽  
Water Side ◽  
Freeze Damage

In areas with hard water, scaling can reduce the reliability of solar hot water (SHW) systems. Common reliability problems associated with scaling are both mechanical (collector freeze damage, clogged passages, premature failure of pumps and valves) and thermal (efficiency degradation). A mechanistic and a mathematical scaling rate model are presented. Results from controlled experiments investigating the effect of key water chemistry and heat transfer parameters on the scaling rate are summarized. The implications of these results for designing SHW systems for scaling environments are discussed. Most importantly, indirect systems where the potable water side of the heat exchanger is integrated into the storage tank wall, such as in a wrap-around heat exchanger, are shown to be the most mechanically and thermally reliable systems for scaling environments. A new version of the software SolScale is discussed, which is intended to aid in the design of SHW systems to reduce scaling related reliability problems.

scholarly journals Evaluation of efficacy of different tooth paste formulations in reducing the oral microbial load - An in vivo study

Biomedicine ◽  
2021 ◽  
Vol 41 (2) ◽  
pp. 465-471
Author(s):  
G Priyal ◽  
Maji Jose ◽  
Shruti Nayak ◽  
Vidya Pai ◽  
Sudeendra Prabhu
Keyword(s):  
Oral Health ◽  
Oral Hygiene ◽  
Antimicrobial Properties ◽  
Microbial Load ◽  
Lactobacillus Species ◽  
Colony Forming Units ◽  
Hygiene Measures ◽  
Microbial Analysis ◽  
Prevotella Species

Introduction and Aim: Toothpastes are the most common preventive means in oral health care. Many commercially available dentifrices claim to have antimicrobial properties, but little research has been conducted to investigate these claims. Therefore, this study was conducted to evaluate the efficacy of different toothpaste formulations in reducing the oral microbial load. Methodology: A total of six types of tooth pastes-4 herbal and 2 non-herbal- were assigned to a group of 20 subjects each, who used it for a period of six weeks. During the course of the study, at the end of 1st, 3rd and 6th week, subgingival plaque samples collected were subjected to microbial analysis. Results: Microbial analysis identified colonies of organisms such as S. mitis, S. mutans, S. salivarius, Peptostreptococcus species, Prevotella species and Lactobacillus species. Colony forming units (cfu) calculated indicated a reduction in microbial load from 1st to 6th week of use of different tooth paste formulations. However statistical analysis of the results did not show significant differences between the groups (p>0.005). Conclusion: The selected tooth paste formulations were effective in controlling the microbial load and therefore contributing to maintain good oral hygiene. However, practicing appropriate oral hygiene measures & brushing technique is of utmost importance in maintaining good oral health than the effectiveness of various ingredients in the toothpastes used.

scholarly journals Evaluation of Antimicrobial Efficacy of Triphala Oral Spray in Patients Undergoing Orthodontic Treatment- A Randomized Clinical Trial

2021 ◽  
pp. 24-29
Author(s):  
Nishi Malviya ◽  
Nilima Thosar ◽  
Nilesh Rathi ◽  
Monika Khubchandani ◽  
V. G. Meshram
Keyword(s):  
Orthodontic Treatment ◽  
Antimicrobial Agents ◽  
Periodontal Diseases ◽  
Drug Formulation ◽  
Microbial Load ◽  
Antimicrobial Efficacy ◽  
Microbial Count ◽  
Oral Streptococci ◽  
Post Intervention ◽  
Plaque Score

Background: Malocclusion is one of the most susceptible causes of the development of periodontal diseases and dental caries in young individuals undergoing fixed orthodontic treatment. It provides a surface area for the accumulation of food particles, which further leads to plaque formation. Various mechanical and chemical aids are used regularly to decrease the microbial load and accumulation of plaque. Chemical adjuncts such as chlorhexidine mouthwash are widely used as antimicrobial agents that have significant efficacy against oral Streptococci and Actinomyces species. Herbal agents have replaced conventional medications due to the development of antibiotic resistance. Among herbal medicaments, Triphala is the well-known drug formulation that can be used as an adjuvant for commercially available chemical aid. Chlorhexidine mouth wash requires the assistance of the caregivers. Therefore, there is a need for a newer modality to maintain oral hygiene in patients undertaking orthodontic corrections. Objectives: 1. To evaluate the antimicrobial efficacy of Triphala oral spray on Streptococcus mutants levels in children undergoing orthodontic treatment. 2. To evaluate the efficacy of Triphala oral spray in reducing dental plaque in children undergoing orthodontic treatment. 3. To evaluate the efficacy of Triphala oral spray reducing gingivitis in children undergoing orthodontic treatment. Methodology: A randomized control trial will be done among – participants with the age group of 10 to 15 years of age. A total of 25 children were included in the study. The participants will be told to use the spray two times a day for one week. After 7 days, plaque index and the gingival index will be re-recorded, and plaque samples will be collected for post-intervention microbial analysis. Results: Triphala-based oral spray will effectively reduce plaque score, reduce gingival inflammation, and show inhibitory effects on microbial count. Conclusion: Triphala oral spray can be used as an adjuvant by the orthodontic patients for reduction of the microbial load. It also provides better acceptability by the children as it does not require any assistance of the caregivers.

scholarly journals Minimum irradiance required to inhibit microbial growth to prevent ventilatorassociated pneumonia by an endotracheal tube equipped with blue LEDs

2021 ◽  
Vol 7 (2) ◽  
pp. 239-242
Author(s):  
Ben Sicks ◽  
Christina Stock ◽  
Sarah Peter ◽  
Tobias Meurle ◽  
Katharina Hoenes ◽  
...  
Keyword(s):  
Endotracheal Tube ◽  
Artificial Respiration ◽  
Antimicrobial Properties ◽  
Glass Tube ◽  
Microbial Reduction ◽  
Microbial Pathogens ◽  
Cellular Damage ◽  
Log Reduction ◽  
Colony Forming Units ◽  
Blue Wavelength

Abstract Artificial respiration is saving lives especially in the COVID-19 pandemic, but it also carries the risk to cause ventilator-associated pneumonia (VAP). VAP is one of the most common and severe nosocomial infections, often leading to death and adding a major economic burden to the healthcare system. To prevent a proliferation of microbial pathogens that cause VAP, an endotracheal tube (ETT) equipped with blue LEDs (LED-ETT) was developed. This blue wavelength exhibits antimicrobial properties but may also harm human tracheal cells at higher irradiances. Therefore, the aim of this study was to find the minimal required irradiance for microbial reduction of 1 log level in 24 h by applying LED-ETTs. A LED-ETT with 48 blue LEDs (450 nm) was fixed in a glass tube, which served as a trachea model. The investigation was carried out with irradiations of 4.2, 6.6 and 13.4 mW/cm² at 37 °C for 24 h. The experiments were performed with Acinetobacter kookii as a surrogate of Acinetobacter baumannii, which is classified as critical by the WHO. Samples of A. kookii suspensions were taken every 4 h during irradiation from the trachea model. Bacteria concentrations were quantified by determining colony forming units (CFU)/ml. A homogeneous irradiance of only 4.2 mW/cm² generated by the blue LEDs, at a LED forward current of 3.125 mA, is sufficient to achieve a 1 log reduction of A. kookii within 24 h. The total irradiation dose within this period was 360 J/cm2. Human cells survive this dose without cellular damage. Previous studies revealed that the pathogen A. baumannii is even more sensitive to blue light than A. kookii. Therefore, blue LED-ETTs are expected to reduce A. baumannii without harming human tracheal cells.

scholarly journals Rappaport-Vassiliadis Medium for Recovery of Salmonellaspp. from Low Microbial Load Foods: Collaborative Study

2001 ◽  
Vol 84 (1) ◽  
pp. 65-84 ◽  
Author(s):  
Thomas S Hammack ◽  
R Miguel Amaguaña ◽  
Wallace H Andrews ◽  
S M Al-Hasani ◽  
R Asmundson ◽  
...  
Keyword(s):  
Guar Gum ◽  
Relative Effectiveness ◽  
Collaborative Study ◽  
Egg Yolk ◽  
Black Pepper ◽  
The Other ◽  
Microbial Load ◽  
Positive Test ◽  
Colony Forming Units ◽  
Dry Milk

Abstract Twenty-three laboratories participated in a collaborative study to compare the relative effectiveness of Rappaport-Vassiliadis (RV) medium incubated at 42°C, selenite cystine (SC) broth (35°C), and tetrathionate (TT) broth (35 and 43°C) for recovery of Salmonella from the following foods with a low microbial load: dried egg yolk, dry active yeast, ground black pepper, guar gum, and instant nonfat dry milk. For dry active yeast, lauryl tryptose (LT) broth, incubated at 35°C, was used instead of SC broth. All of the foods were artificially inoculated with single Salmonella serovars, that had been lyophilized before inoculation, at high and low target levels of 0.4 and 0.04 colony forming units/g food, respectively. For analysis of 870 test portions, representing all of the foods except yeast, 249 Salmonella-positive test portions were detected by RV medium, 265 by TT broth (43°C), 268 by TT broth (35°C), and 269 by SC broth (35°C). For analysis of 225 test portions of yeast, 79 Salmonella-positive test portions were detected by RV medium, 79 by TT broth (43°C), 84 by TT broth (35°C), and 68 by LT broth (35°C). RV medium was comparable to, or even more effective than, the other selective enrichments for recovery of Salmonella from all of the foods except guar gum. It is recommended that RV (42°C) and TT (35°C) be used with foods that have a low microbial load, except for guar gum for which SC (35°C) and TT (35°C) are recommended.

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