Biological indicators for steam sterilization: characterization of a rapid biological indicator utilizingBacillus stearothermophilusspore-associated alpha-glucosidase enzyme

1998 ◽  
Vol 85 (5) ◽  
pp. 865-874 ◽  
Author(s):  
H. Albert ◽  
D. J. G. Davies ◽  
L. P. Woodson ◽  
C. J. Soper
Keyword(s):  
Biological Indicators ◽  
Biological Indicator ◽  
Steam Sterilization ◽  
Alpha Glucosidase

scholarly journals Influence of Bacillus Stearothermophilus generations in the production of its spores

2010 ◽  
Vol 1 (1) ◽  
pp. 53
Author(s):  
Roselene Ferreira Oliveira ◽  
Heron Oliveira dos Santos Lima ◽  
Mirela Vanin dos Santos Lima
Keyword(s):  
Quality Assurance ◽  
Thermal Resistance ◽  
Bacillus Stearothermophilus ◽  
Culture Media ◽  
Biological Indicators ◽  
Biological Indicator ◽  
Physical Parameters ◽  
Steam Sterilization ◽  
Sporulation Process ◽  
Pharmaceutical Industries

<p>The validation of sterilization processes in food and pharmaceutical industries is a major tool for quality assurance, making the products safe, effective and reliable. Biological indicators, formed by spores of Bacillus stearothermophilus microorganisms considered at higher thermal resistance, are used to evaluate and monitor the physical parameters of a cycle of steam sterilization. In this way this study aimed to cultivate and characterize the microorganism Bacillus stearothermophilus generations, assessing the influence of these generations in the parameters of resistance, formation and concentration of its spores to be used in the production of biological indicators. The experiments were conducted cultivating the 1st, 2nd and 3rd generations of B. stearothermophilus in suitable culture media for sporulation, in Roux bottles, for a period of 15 days of incubation. During these 15 days, the sporulation process was evaluated by microscopy, according to Wirtz-Conklin's method, every 24 hours of incubation. The results showed that the generations do influence the sporulation process, indicating that the 3rd generation is the most suitable for the production of formed spores, in concentration and thermal resistance appropriate characteristics to the needs of a biological indicator to efficiently validate and monitor steam sterilization cycles.</p><p>&nbsp;</p><p><a href="http://dx.doi.org/10.14685/rebrapa.v4i1.116">http://dx.doi.org/10.14685/rebrapa.v1i1.12</a></p>

Comparison of a Rapid Readout Biological Indicator for Steam Sterilization With Four Conventional Biological Indicators and Five Chemical Indicators

1996 ◽  
Vol 17 (7) ◽  
pp. 423-428 ◽  
Author(s):  
William A. Rutala ◽  
Suzanne M. Jones ◽  
David J. Weber
Keyword(s):  
Exposure Time ◽  
Color Change ◽  
Biological Indicators ◽  
Biological Indicator ◽  
Failure Rates ◽  
Steam Sterilization ◽  
Chemical Indicators

AbstractObjective:In this study, we compare a new biological indicator that provides results within 3 hours with four conventional, 48-hour biological indicators and five chemical indicators.Design:Biological indicators tested included the conventional Attest 1262, Proof Plus, Assert, and Biosign, and the new Attest 1292 Rapid Readout biological indicator. Chemical indicators tested included Comply, Propper, Chemdi, Sterigage, and Thermalog S. Spore survival following 121°C in a gravity displacement sterilizer was measured by media color change after incubation for 24 and 48 hours at 56°C for the conventional biological indicators, fluorescence at 3 hours for the Attest 1292 Rapid Readout biological indicator, and color change for the chemical indicators. Each exposure time was replicated 12 times with five samples of each indicator per run (ie, 60 replicates per indicator).Results:At 48 hours, the conventional biological indicators Attest 1262, Proof Plus, Assert, and Biosign showed 100%, 95%, 88%, and 93% spore survival at 5 minutes' exposure; 0%, 0%, 0%, and 8% at 10 minutes; and all showed 0% survival at 15 minutes' exposure. Following a 3hour incubation, the Attest 1292 Rapid Readout biological indicator showed fluorescence at 100%, 72%, and 0% at 5, 10, and 15 minutes, respectively. The chemical indicators Comply, Propper, Chemdi, Sterigage, and Thermalog S revealed sterilization failure rates of 100%, 100%, 100%, 100%, and 100% at 5 minutes' exposure; 0%, 0%, 0%, 92%, and 100% at 10 minutes; and, 0%, 0%, 0%, 3%, and 27% at 15 minutes' exposure, respectively.Conclusions:The sensitivity of the Attest 1292 Rapid Readout biological indicator parallels that of conventional biological indicators. These data suggest that a 3hour rapid readout biological indicator is equivalent to a standard 48-hour biological indicator. Some chemical indicators (eg, Thermalog S) failed to indicate adequate sterilization at 15 minutes' exposure. These chemical indicators have the potential of causing unnecessary recall of adequately sterilized items.

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>

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