scholarly journals Determination of decimal reduction time (D-value) of chemical agents used in hospitals for killing airborne isolated bacteria

2013 ◽  
Vol 7 (26) ◽  
pp. 3321-3330 ◽  
Author(s):  
Aly Amer Ranya ◽  
Aly Mady Safinaz ◽  
H Yusef Hoda ◽  
Sabry Soraya
Keyword(s):  
Decimal Reduction Time ◽  
Reduction Time ◽  
Chemical Agents ◽  
D Value

scholarly journals Determination of decimal reduction time (D-value) of chemical agents used in hospital disinfection

2003 ◽  
Vol 34 ◽  
pp. 33-34 ◽  
Author(s):  
Priscila Gava Mazzola ◽  
Alzira Maria da Silva Martins ◽  
Thereza Christina Vessoni Penna
Keyword(s):  
Decimal Reduction Time ◽  
Reduction Time ◽  
Chemical Agents ◽  
D Value

scholarly journals Determination of decimal reduction time (D value) of chemical agents used in hospitals for disinfection purposes

2003 ◽  
Vol 3 (1) ◽  
Author(s):  
Priscila Gava Mazzola ◽  
Thereza Christina Vessoni Penna ◽  
Alzira M da S Martins
Keyword(s):  
Decimal Reduction Time ◽  
Reduction Time ◽  
Chemical Agents ◽  
D Value

scholarly journals Clean-Test self-contained biological indicator performance used to steam sterilization process validation.

2012 ◽  
Vol 2 (1) ◽  
pp. 38
Author(s):  
Thiago José Pelissari ◽  
Heron Oliveira dos Santos Lima ◽  
Mirela Vanin dos Santos Lima
Keyword(s):  
Incubation Time ◽  
Time Pressure ◽  
Biological Indicators ◽  
Biological Indicator ◽  
Initial Population ◽  
Steam Sterilization ◽  
Microbial Resistance ◽  
Decimal Reduction Time ◽  
D Value

<p>Clean-Test self-contained biological indicators are used to monitor steam sterilization cycles. Each biological indicator has a minimum population of 10<sup>5</sup> or 10<sup>6</sup> UFC bacterial spores of <em>Geobacillus stearothermophilus</em> ATCC 7953. The purpose of this work was to study the behavior of Clean-Test self-contained biological indicator used to monitor and validate steam sterilization systems, in relation to the incubation time (24, 48 hours and 7 days) and the performance of microbial resistance at different conditions of time, pressure and temperature. The analyses were performed starting with the evaluation of lots of biological indicators by determining the initial population (N<sub>0</sub>), determination of D value (decimal reduction time), determination of survival and death times for the microorganisms. Then&nbsp; was studied the resistance performance&nbsp; of the biological indicator Clean-Test at different exposure times, temperatures and pressure, as well as the evaluation and analysis of the relationship between incubation time and growth rate for periods of 24, and 48 hours 7 days. The behavior of biological indicator when the temperature and pressure were increased was inversely proportional to D value (microbial resistance). The lot behavior of positive biological indicators by the end of seven days of incubation indicated minimal results of 97%, satisfactory acceptability which is acceptable according to ANSI/AAMI/ISO 11138-1:(2006)because the lots of biological indicators tested met its requirements.</p><p>&nbsp;</p><p>DOI: http://dx.doi.org/10.14685/rebrapa.v2i1.45</p>

Fungicidal Activity of Five Disinfectants on Isolates of Candida Species

2021 ◽  
Author(s):  
Helena Lucia Martinez Bajaire ◽  
Claudia Marcela Parra Giraldo ◽  
Jorge Alberto Cortes Luna ◽  
Janeth Arias Palacios
Keyword(s):  
Death Rate ◽  
Quantitative Methods ◽  
Fungicidal Activity ◽  
Culture Media ◽  
Infectious Agent ◽  
Media Analysis ◽  
Candida Auris ◽  
Environmental Strain ◽  
Decimal Reduction Time ◽  
Reduction Time

Abstract Determine fungicidal activity of five disinfectants on Candida auris of clinical and environmental origin. Assess fungicidal efficiency of each disinfectants on the microorganism. Calculate percentage of efficiency (% E) of each disinfectants on Candida strain and determine specific death rate (k) and decimal reduction time for the microorganism. An analytic and experimental research with quantitative methods. We realized a strains workbench by culturing it in corresponding culture media. Analysis was a challenge essay, performed on four surfaces and at different exposure times; 1, 5, 15 and 30 minutes of contact between disinfectant and yeast. Once disinfection process was carried out, what was expected was that after 15 minutes of contact between the yeasts and the disinfectants, a percentage of inhibition of the microorganism between 90 and 95% was presented, thus guaranteeing the duration of elimination of the infectious agent by disinfectants. Results shows that after one minute of contact between Candida auris and the disinfectant in a gloved hand, there was a removal of the yeast, when the clinical and environmental strain were analyzed. Data showing disinfectants efficiency percentages greater than 90% over strains of Candida used in the study. Decimal reduction times in seconds of the strains of Candida against the disinfectants used in the study were between 9.3 and 14.04 s. It was possible to evaluate effectiveness by means inhibition percentage of each disinfectants on the strains of Candida auris of clinical and environmental origin. Similarly, specific death rate and decimal reduction time in seconds were determined for strains under study.

scholarly journals Choice of sterilizing/disinfecting agent: determination of the Decimal ReductionTime (D-Value)

2009 ◽  
Vol 45 (4) ◽  
pp. 701-708 ◽  
Author(s):  
Priscila Gava Mazzola ◽  
Angela Faustino Jozala ◽  
Letícia Célia de Lencastre Novaes ◽  
Patricia Moriel ◽  
Thereza Christina Vessoni Penna
Keyword(s):  
Medical Devices ◽  
Cross Contamination ◽  
Decimal Reduction Time ◽  
E Coli ◽  
Health Care Unit ◽  
Sodium Dichloroisocyanurate ◽  
D Values ◽  
Spread Of Infection ◽  
Disinfectant Efficacy

Efforts to diminish the transmission of infections include programs in which disinfectants play a crucial role. Hospital surfaces and medical devices are potential sources of cross contamination, and each instrument, surface or area in a health care unit can be responsible for spread of infection. The decimal reduction time was used to study and compare the behavior of selected strains of microorganisms. The highest D-values for various bacteria were obtained for the following solutions: (i) 0.1% sodium dichloroisocyanurate (pH 7.0) - E. coli and A. calcoaceticus (D = 5.9 min); (ii) sodium hypochlorite (pH 7.0) at 0.025% for B. stearothermophilus (D = 24 min), E. coli and E. cloacae (D = 7.5 min); at 0.05% for B. stearothermophilus (D = 9.4 min) and E. coli (D = 6.1 min). The suspension studies were an indication of the disinfectant efficacy on a surface. The data in this study reflect the formulations used and may vary from product to product. The expected effectiveness from the studied formulations shows that the tested agents can be recommended for surface disinfection as stated in present guidelines and emphasize the importance and need to develop routine and novel programs to evaluate product utility.

scholarly journals Statistical Modelling of the Number of Infected Fruiting Bodies of Common Mushrooms in Cultivation Integrated with Preparations Containing Beneficial Microorganisms

2018 ◽  
Vol 22 (3) ◽  
pp. 75-84
Author(s):  
Katarzyna Szwedziak ◽  
Ewa Polańczyk
Keyword(s):  
Statistical Evaluation ◽  
Statistical Modelling ◽  
Alternative Methods ◽  
Fruiting Bodies ◽  
Chemical Agents ◽  
Beneficial Microorganisms ◽  
Protection Method

AbstractDue to low effectiveness or high costs of using chemical agents in the protection of common mushrooms, producers are forced to look for alternative methods of protection. One such method is the use of preparations containing beneficial microorganisms. A statistical evaluation of this mushroom protection method and determination of the number of infected fruiting bodies is presented in this paper

Persistence of Mycobacterium bovis BCG in Soil and on Vegetables Spray-Irrigated with Sewage Effluent and Sludge

1977 ◽  
Vol 40 (3) ◽  
pp. 160-163 ◽  
Author(s):  
DALE J. VAN DONSEL ◽  
EDWARD P. LARKIN
Keyword(s):  
Survival Rate ◽  
Mycobacterium Bovis ◽  
Sewage Effluent ◽  
Mycobacterium Bovis Bcg ◽  
Reduction Time ◽  
D Value ◽  
Current Practices

Survival of Mycobacterium bovis BCG on garden plots spray-irrigated with sewage effluent or sludge was studied to determine persistence of mycobacteria under conditions approximating current practices. The D value (90% reduction time) in effluent-sprayed soil was 11 days, and in sludge-sprayed soil it was 8 days. On effluent-sprayed radishes, the D value was 6 days, and on sludge-sprayed radishes, 4 days; however, this difference was not significant. Isolation from lettuce was too erratic to determine a true survival rate, but the organism was isolated sporadically for up to 35 days.

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