scholarly journals The Optimum Duration of Flushing Dental Unit Waterlines for Microbial Removal

2021 ◽  
Vol 16 (1) ◽  
pp. 13-23
Author(s):  
John Chong Keat Hon ◽  
Siti Noor Adnalizawati Adnan ◽  
Nur Aqilah Ismail
Keyword(s):  
Heterotrophic Bacteria ◽  
Dental Treatment ◽  
Oral Surgery ◽  
Plate Count ◽  
Optimum Duration ◽  
Plate Count Agar ◽  
Dental Clinics ◽  
Number Of Microorganisms ◽  
Control And Prevention ◽  
Dental Unit Waterlines

This study aims to evaluate the optimum duration of flushing dental unit waterlines (DUWLs) in Universiti Sains Islam Malaysia (USIM) dental polyclinics for removal of heterotrophic bacteria. Water samples were obtained from triple air syringes at each dental chair from oral surgery clinic, outpatient clinic and polyclinic 17 at Faculty of Dentistry, USIM after 16 and 64 hours of not operating the dental units as baseline samples. This is followed by sampling after continuous flushing at 30 seconds, 1 minute, 2 minutes and 3 minutes of flushing duration. The levels of heterotrophic plate count (HPC) for each flushing duration were determined by quantification of colony forming units (CFUs) after cultivation of samples on plate count agar (PCA), R2A agar and 5% sheep blood agar (SBA). Statistically, there was no significant reduction in CFUs of HPC for all flushing duration compared to baseline (P > 0.05) with the most notable HPC reducing level after 1 minute and 3 minutes of flushing DUWLs. However, HPC level at USIM dental clinics is still exceeding the recommendation by Centers for Disease Control and Prevention (CDC) which should be less than 500 CFU/mL. The existing method of controlling DUWLs contamination in USIM dental clinics is only by flushing DUWLs 1 minute every morning prior to dental treatment as recommended by Malaysian Dental Council (MDC) without the use of chemical germicides. Thus, the flushing method alone is not reliable to reduce the number of microorganisms in the DUWLs.

scholarly journals Microbial contamination in dental unit waterlines

2003 ◽  
Vol 14 (1) ◽  
pp. 55-57 ◽  
Author(s):  
Maria Cristina Monteiro de Souza-Gugelmin ◽  
Carolina Della Torre Lima ◽  
Sergio Narciso Marques de Lima ◽  
Henis Mian ◽  
Izabel Yoko Ito
Keyword(s):  
High Speed ◽  
Microbial Contamination ◽  
Water Reservoir ◽  
Plate Count ◽  
Plate Count Agar ◽  
Quality Of Water ◽  
Colony Forming Units ◽  
Dental Staff ◽  
Dental Unit Waterlines

The quality of water in a dental unit is of considerable importance because patients and dental staff are regularly exposed to water and aerosol generated from the dental unit. The aim of this study was to evaluate the occurrence of microbial contamination in dental unit waterlines. Water samples were collected aseptically from the waterlines (reservoir, triple-syringe, high-speed) of 15 dental units. After serial dilution to 1:10(6) in APHA, the samples were seeded by the pour-plate technique and cultured in plate count agar (Difco) for 48 h at 32ºC. Analysis was based on the number of colony forming units (CFU). The Wilcoxon non-parametric test indicated that the levels of water contamination were highest in the triple-syringe (13 of 15) and in the high-speed (11 of 15); both levels were higher than those of the water reservoir. There was no significant statistical difference between the level of contamination in the triple-syringe and the high-speed as determined by the Mann-Whitney test [p(H0) = 40.98%; Z = - 0.2281]. Because biofilm forms on solid surfaces constantly bathed by liquid where microorganisms are present, these results indicate that the water in the dental unit may be contaminated by biofilm that forms in these tubules.

scholarly journals Bacteriological and Phytochemical Assessment of Ficus asperifolia Linn. Infusion

2020 ◽  
Vol 2020 ◽  
pp. 1-5
Author(s):  
Kolapo Ayoola Fasina ◽  
Titilayo O. Adesetan ◽  
Faithfulness Oseghale ◽  
Haneefat O. Egberongbe ◽  
O. O. Aghughu ◽  
...  
Keyword(s):  
Heterotrophic Bacteria ◽  
Analytical Techniques ◽  
Plate Count ◽  
Phytochemical Analysis ◽  
Microbiological Analysis ◽  
Determinative Bacteriology ◽  
Biochemical Tests ◽  
Plate Method ◽  
Plate Count Agar ◽  
Yoruba Language

Ficus asperifolia Linn. known as “Eepin” in Yoruba language, or sand paper tree, is a monoecious fig tree whose leaves, bark, seeds, and roots have been used locally in treating many infectious and noninfectious diseases. The study is aimed at investigating the bacteriological and phytochemical potential of Ficus asperifolia Linn. The roots of the plant were harvested and washed, and phytochemical analysis was carried out using standard analytical techniques. Infusion was aseptically prepared, and incubation for 24 hours and microbiological analysis were carried out using the pour plate method on Plate Count Agar (PCA) and Nutrient Agar (NA). Microorganisms were subcultured and identified using morphological and biochemical tests according to “Bergey’s Manual of Determinative Bacteriology.” Phytochemical analysis of the fresh and dry roots revealed the presence of alkaloids, cardenolides, and saponins, while anthraquinones and tannins were absent. Total heterotrophic bacteria count on PCA was 5.6×105 CFU/ml, while on NA, it was 2.3×105 CFU/ml, and four classes of bacteria were isolated including Klebsiella sp., Escherichia coli, Proteus sp., and Bacillus sp. Although the presence of medicinal phytochemicals in F. asperifolia Linn. indicates strong potentials for its use in infusions, the presence of potential pathogens found in the infusions makes it unsafe for consumption.

Comparison of Methods for Determining Coliform and Escherichia coli Levels in Apple Cider†

1997 ◽  
Vol 60 (11) ◽  
pp. 1302-1305 ◽  
Author(s):  
TODD M. SILK ◽  
ELLIOT T. RYSER ◽  
CATHERINE W. DONNELLY
Keyword(s):  
Escherichia Coli ◽  
Heterotrophic Bacteria ◽  
High Sensitivity ◽  
Low Ph ◽  
Coliform Bacteria ◽  
Plate Count ◽  
Apple Cider ◽  
E Coli ◽  
Plate Count Agar ◽  
Positive Results

The main objective of this research was to determine the easiest and most reliable media for enumerating coliform bacteria and Escherichia coli levels in apple cider. During the autumn of 1994 a total of 59 apple cider samples were collected directly from 12 cider producers and were assessed for bacterial levels and pH. Plate count agar was used to determine heterotrophic bacteria levels. Coliform levels were determined using three different media: violet red bile agar (VRBA), Petrifilm High Sensitivity Coliform Count Plates (PHSCCP), and Trypticase soy agar with a VRBA overlay (TSA/VRBA) for attempted recovery of coliforms injured by the low pH of the apple cider. Eosin methylene blue agar (EMBA) and Petrifilm E. coli Count Plates were used to screen cider samples for E. coli. Apple cider had an average pH of 3.34 ± 0.08. Heterotrophic bacterial levels ranged from 2.30 to 7.11 log CFU/ml. All cider samples contained coliform bacteria with levels varying greatly; on the different media, we found the following: on VRBA, <1.00 to 4.37 log CFU/ml; on TSA/VRBA, 1.20 to 4.40 log CFU/ml; and on PHSCCP, < 1.00 to 4.56 log CFU/ml. Coliform levels were most easily determined in apple cider by using PHSCCP. However TSA/VRBA proved to be more reliable; coliform detection was significantly (P < 0.05) increased. EMBA was ineffective for screening apple cider for E. coli, with the low pH of the cider producing many false-positive results. E. coli was only recovered by using Petrifilm E. coli Count Plates with one of the 59 samples positive for E. coli (non-O157:H7) at a level of 10 CFU/ml.

Improved detection of acid mine water stressed coliform bacteria on media containing catalase and sodium pyruvate

1990 ◽  
Vol 36 (8) ◽  
pp. 544-550 ◽  
Author(s):  
Joseph P. Calabrese ◽  
Gary K. Bissonnette
Keyword(s):  
Mine Water ◽  
Membrane Filtration ◽  
Heterotrophic Bacteria ◽  
Coliform Bacteria ◽  
Plate Count ◽  
Acid Mine Water ◽  
Sodium Pyruvate ◽  
Acid Mine ◽  
Plate Count Agar

Pure culture suspensions of two strains of exponential and stationary phase Escherichia coli exhibited significant reductions in catalase activity following exposure to acid mine water (AMW). The exogenous addition of catalase (500–2000 U) or sodium pyruvate (0.05–5%) to a nonselective recovery medium resulted in enhanced detection (12- to 465-fold) of AMW-stressed E. coli as compared with recovery on the medium lacking these supplements, whereas addition of 3,3′-thiodipropionic acid failed to improve recovery. Additional in vitro experiments utilizing selective M-FC, mT7, and M-Endo media containing 1000 U catalase or 1.0% pyruvate similarly resulted in improved detection of AMW-stressed cells, with the exception of M-Endo containing pyruvate. Appropriately modified media were then used to analyze an AMW-impacted stream by the membrane filtration technique. Addition of catalase, pyruvate, or a combination of both significantly improved recovery of fecal and total coliforms without promoting growth of noncoliforms. Supplementation of plate count agar with pyruvate and (or) catalase enhanced detection of total heterotrophs. These findings suggest that addition of catalase or pyruvate to standard recovery media may improve detection of coliform and total heterotrophic bacteria in AMW-impacted waters. Key words: acid mine water, coliforms, stress.

An estuarine agar medium for enumeration of aerobic heterotrophic bacteria associated with water, sediment, and shellfish

1980 ◽  
Vol 26 (11) ◽  
pp. 1366-1369 ◽  
Author(s):  
Ronald M. Weiner ◽  
David Hussong ◽  
Rita R. Colwell
Keyword(s):  
Yeast Extract ◽  
Heterotrophic Bacteria ◽  
Agar Medium ◽  
Plate Count ◽  
Bacterial Populations ◽  
Standard Plate Count ◽  
Plate Count Agar ◽  
Standard Plate ◽  
Plate Counts ◽  
Yeast Extract Agar

A plate count agar was formulated for use in bacteriological analysis of estuarine samples and was tested together with standard plate count agar and an estuarine salts yeast extract agar for growth of aerobic, heterotrophic bacteria in water, sediment, and oysters. The estuarine agar was found to be efficient for enumerating aerobic, heterotrophic bacterial populations of water, sediment, and oysters, and is recommended for plate counts of estuarine samples.

scholarly journals Evaluation of bacterial and fungal contamination of kitchens of Birjand University of Medical Sciences

2019 ◽  
Vol 12 (1) ◽  
Author(s):  
Seyyedeh Masoomeh Rahimi ◽  
Maryam Ebrahimi ◽  
Behnam Barikbin ◽  
Tayebeh Zeinali
Keyword(s):  
Disease Transmission ◽  
Bacterial Contamination ◽  
Plate Count ◽  
Storage Site ◽  
Medical Sciences ◽  
Fungal Contamination ◽  
Sabouraud Dextrose Agar ◽  
Plate Count Agar ◽  
Control And Prevention ◽  
The Mean

Abstract Objective This study aims to evaluate the total bacterial and fungal count of tools, devices and surfaces of kitchens of the centers affiliated to Birjand University of Medical Sciences. In this study, 200 samples from four kitchens of Birjand University of Medical Sciences were obtained. After the preparation of serial dilutions, samples were cultured in plate count agar (PCA) plates and Sabouraud dextrose agar (SDA). After incubation at 37 and 25 °C for 24–48 and 72–96 h respectively, the microbial and fungal colonies were counted. Results The mean bacterial and fungal count of kitchens was 7.7 * 107 and 7.6 * 104, respectively. The highest and lowest levels of bacterial contamination were related to tools/devices and cover of tools/work clothes and the highest and lowest levels of fungal count were related to forks and spoons and the tools and devices of the storage site. The rate of contamination in the kitchens of Birjand University of Medical Sciences was relatively high. Thus, serious, continuous and accurate monitoring of the units, training of people working in all stages of cooking and disinfection the tools and devices are essential for control and prevention of disease transmission.

scholarly journals Perspectives from Dentists, Dental Assistants, Students, and Patients on Dental Care Adapted to the COVID-19 Pandemic: A Cross-Sectional Survey

2021 ◽  
Vol 18 (8) ◽  
pp. 3940
Author(s):  
Maximiliane Amelie Schlenz ◽  
Alexander Schmidt ◽  
Bernd Wöstmann ◽  
Andreas May ◽  
Hans-Peter Howaldt ◽  
...  
Keyword(s):  
Patient Care ◽  
Dental Care ◽  
Health Care Professionals ◽  
Dental Treatment ◽  
Cross Sectional Survey ◽  
Cross Sectional ◽  
Safety Measures ◽  
Dental Clinics ◽  
Positive Perspective ◽  
Dental Assistants

Dental care has been affected by SARS-CoV-2 (COVID-19) worldwide. In contrast to other dental clinics, the Justus-Liebig-University Giessen (Germany) decided not to limit dental treatment to emergencies alone, but to continue dental care for all patients, with increased safety measures. As such, health care professionals may be exposed to additional physical and mental stress. The aim of this study was to assess the perspectives of all persons involved in dental care (dentists, dental assistants, students, and patients) regarding the aspects of safety measures, anxiety about self-infection and infecting others, and other prospects in the period March to December 2020 using a questionnaire. Data collection was performed between 14 December 2020 and 23 January 2021. A total of 35 dentists (response rate of 79.5%), 23 dental assistants (65.7%), 84 students (80%), and 51 patients (21.8%) completed the survey. The patients did not notice any changes in the care received. Dentists and dental assistants reported a higher workload due to additional safety measures. The majority of dentists, students, and patients agreed that normal patient care was maintained. One-third of dental assistants would have preferred emergency treatment alone and expressed significantly higher anxiety about COVID-19 infection than all other groups (p < 0.05). In conclusion, all groups showed a predominantly positive perspective on dental care, and anxiety about self-infection and infecting others was especially low. However, additional measures are time-consuming and compound daily patient care. This concept, based on well-established infection control, might be a viable proposal for current and future pandemics.

O impacto da Covid-19 na Odontologia – revisão sistemática

2021 ◽  
Vol 12 (46) ◽  
pp. 15-22
Author(s):  
Ana de Lourdes Sá de Lira ◽  
Francisca Janiele de Sousa
Keyword(s):  
Risk Factors ◽  
Systematic Review ◽  
Dental Care ◽  
Dental Treatment ◽  
Dental Trauma ◽  
Urgent Care ◽  
Inclusion Criteria ◽  
Dental Clinics ◽  
Mode Of Transmission ◽  
Irreversible Pulpitis

This study aimed to review, qualify and summarize the existing evidence on associations and risk factors for Covid-19 during dental treatment and dentists’ knowledge about these risks. After being registered with PROSPERO, the systematic review was carried out in accordance with the PRISMA guidelines, with searches in electronic databases, in specific journals, manual searches and Google Scholar, without language restrictions, from December 2019 to August 2020. Two questions were asked to be investigated: did patients seek dental care in the emergency room and do dentists know the symptoms and the mode of transmission of Covid-19, feeling qualified to attend them? Only 6 articles were included because they met all defined inclusion criteria. It was concluded that endodontic urgencies and emergencies with symptomatic irreversible pulpitis are the most common, consisting of a much higher proportion of dental emergencies during Covid-19 epidemic compared with dental trauma and no-urgent care. Although dentists are aware of the symptoms, mode of transmission, infection controls, and measures in dental clinics, they do not feel confident about the correct measures to be taken to prevent Covid-19 for their staff and patients.

Comparison of the Petrifilm™ Yeast and Mold Culture Film Method to Conventional Methods for Enumerating Yeasts and Molds in Foods

1991 ◽  
Vol 54 (6) ◽  
pp. 443-447 ◽  
Author(s):  
L. R. BEUCHAT ◽  
B. V. NAIL ◽  
R.E. BRACKETT ◽  
T. L. FOX
Keyword(s):  
Correlation Coefficients ◽  
Food Group ◽  
Black Pepper ◽  
Plate Count ◽  
Food Groups ◽  
Plate Count Agar ◽  
Plate Counts ◽  
Yeasts And Molds ◽  
Potential Food ◽  
Film Method

Petrifilm™ Yeast and Mold (YM) plates were compared to acidified potato dextrose agar (APDA) and chloramphenicol-supplemented plate count agar (CPCA) for its suitability to enumerate yeasts and molds in 13 groups of food products. These products consisted of beans (dry and frozen, green), corn meal, flour (wheat), fruit (apple), a meat/vegetable entree (chicken pot pie), a precooked meat (beef), milk (dehydrated, nonfat), nuts (pecans), pasta, potatoes (dehydrated), precooked sausage, and a spice (black pepper). Correlation coefficients of Petrifilm™ YM plates versus APDA and CPCA pour plates for recovering total yeasts and molds from a composite of the thirteen test foods were, respectively, 0.961 and 0.974. Individually, Petrifilm™ YM plate counts were equivalent or higher than APDA and CPCA for some food groups and lower for other food groups. Because food particle interference can make enumeration of yeast and mold colonies on Petrifilm™ YM plates difficult for some food groups, potential food interference will need to be evaluated for each food group tested.

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