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

Mazzola, Priscila Gava; Penna, Thereza Christina Vessoni; Martins, Alzira Maria da Silva

doi:10.1186/1471-2334-3-24

Cited by 96 publications

(64 citation statements)

References 9 publications

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“…Several CECMEL11 antifungal peptides have been found to be sporicidal against F. oxysporum and P. expansum at concentrations around the MIC. Notably, the best peptides killed 99 to 99.9% of the F. oxysporum spores in 35 min at 20 M. These results correspond to decimal reduction times of 10 to 15 min, which are comparable with the ones reported for currently used antiseptics and disinfectants (30). Moreover, the correlation observed between sporicidal activity and Sytox green uptake suggests that fungal membrane disruption could be the primary mode of action.…”

Section: Discussionsupporting

confidence: 73%

Sporicidal Activity of Synthetic Antifungal Undecapeptides and Control of Penicillium Rot of Apples

Badosa

Ferré

Francés

et al. 2009

Appl Environ Microbiol

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The antifungal activity of cecropin A(2-8)-melittin(6-9) hybrid undecapeptides, previously reported as active against plant pathogenic bacteria, was studied. A set of 15 sequences was screened in vitro against Fusarium oxysporum, Penicillium expansum, Aspergillus niger, and Rhizopus stolonifer. Most compounds were highly active against F. oxysporum (MIC < 2.5 M) but were less active against the other fungi. The best peptides were studied for their sporicidal activity and for Sytox green uptake in F. oxysporum microconidia. A significant inverse linear relationship was observed between survival and fluorescence, indicating membrane disruption. Next, we evaluated the in vitro activity against P. expansum of a 125-member peptide library with the general structure R-X 1 KLFKKILKX 10 L-NH 2 , where X 1 and X 10 corresponded to amino acids with various degrees of hydrophobicity and hydrophilicity and R included different N-terminal derivatizations. Fifteen sequences with MICs below 12.5 M were identified. The most active compounds were BP21 {Ac,F,V} and BP34 {Ac,L,V} (MIC < 6.25 M), where the braces denote R, X 1 , and X 10 positions and where Ac is an acetyl group. The peptides had sporicidal activity against P. expansum conidia. Seven of these peptides were tested in vivo by evaluating their preventative effect of inhibition of P. expansum infection in apple fruits. The peptide Ts-FK LFKKILKVL-NH 2 (BP22), where Ts is a tosyl group, was the most active with an average efficacy of 56% disease reduction, which was slightly lower than that of a commercial formulation of the fungicide imazalil.

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Section: Discussionsupporting

confidence: 73%

Sporicidal Activity of Synthetic Antifungal Undecapeptides and Control of Penicillium Rot of Apples

Badosa

Ferré

Francés

et al. 2009

Appl Environ Microbiol

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“…Treatment efficiency can be proved by the release of DPA to the suspension after the alkaline treatment and TEM observations. It has been previously reported that inactivation of G. stearothermophilus at low temperatures (<100 o C) can be achieved using chemicals agents (Mazzola et al, 2003;Rogers et al, 2007), high-pressure carbon dioxide (Watanabe et al, 2003) and supercritical carbon dioxide with added hydrogen peroxide (Hemmer et al, 2007) but the time required to inactivate spores is high. The D-values found in literature for inactivation assays carried out at temperature 100 o C were higher than those obtained in this work (Table S1), except when using high pressure treatments (Patazca et al, 2006).…”

Section: Discussionmentioning

confidence: 99%

Inactivation of Geobacillus stearothermophilus spores by alkaline hydrolysis applied to medical waste treatment

Pinho

Nunes

Lobo-da-Cunha

et al. 2015

Journal of Environmental Management

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Although alkaline hydrolysis treatment emerges as an alternative disinfection/sterilization method for medical waste, information on its effects on the inactivation of biological indicators is scarce. The effects of alkaline treatment on the resistance of Geobacillus stearothermophilus spores were investigated and the influence of temperature (80 o C, 100 o C and 110 o C) and NaOH concentration was evaluated. In addition, spore inactivation in the presence of animal tissues and discarded medical components, used as surrogate of medical waste, was also assessed. were approximately 3 times lower than those at 100 o C (8.8e1.6 min). Independent of the presence of animal tissues and discarded medical components, 6 log10 reduction times varied between 66 and 5 min at 100 o C-0.1 M NaOH and 110 o C-1 M NaOH, respectively. The alkaline treatment may be used in future as a disinfection or sterilization alternative method for contaminated waste.

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“…To be able to put a value to biocide activity, two measures have been used, the D and E values. The D value is the time taken to reduce a population of indicator organisms either in suspension or attached to a surface (carrier test) by 90% (126). For instance, the D value of 0.025% sodium hypochlorite at pH 7 against E. coli is 6.1 min (126).…”

Section: Biocidesmentioning

confidence: 99%

“…The D value is the time taken to reduce a population of indicator organisms either in suspension or attached to a surface (carrier test) by 90% (126). For instance, the D value of 0.025% sodium hypochlorite at pH 7 against E. coli is 6.1 min (126). Carrier tests are considered to be a more appropriate measure of biocide activity; these are tests in which the bacteria are attached to a surface, often after formation of a biofilm, and are considered to be less susceptible to antimicrobial compounds than bacteria grown in suspension (109).…”

Section: Biocidesmentioning

confidence: 99%

Clinically Relevant Chromosomally Encoded Multidrug Resistance Efflux Pumps in Bacteria

2006

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SUMMARY Efflux pump genes and proteins are present in both antibiotic-susceptible and antibiotic-resistant bacteria. Pumps may be specific for one substrate or may transport a range of structurally dissimilar compounds (including antibiotics of multiple classes); such pumps can be associated with multiple drug (antibiotic) resistance (MDR). However, the clinical relevance of efflux-mediated resistance is species, drug, and infection dependent. This review focuses on chromosomally encoded pumps in bacteria that cause infections in humans. Recent structural data provide valuable insights into the mechanisms of drug transport. MDR efflux pumps contribute to antibiotic resistance in bacteria in several ways: (i) inherent resistance to an entire class of agents, (ii) inherent resistance to specific agents, and (iii) resistance conferred by overexpression of an efflux pump. Enhanced efflux can be mediated by mutations in (i) the local repressor gene, (ii) a global regulatory gene, (iii) the promoter region of the transporter gene, or (iv) insertion elements upstream of the transporter gene. Some data suggest that resistance nodulation division systems are important in pathogenicity and/or survival in a particular ecological niche. Inhibitors of various efflux pump systems have been described; typically these are plant alkaloids, but as yet no product has been marketed.

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

Abstract: Background: Prior to the selection of disinfectants for low, intermediate and high (sterilizing) levels, the decimal reduction time, D-value, for the most common and persistent bacteria identified at a health care facility should be determined.

Cited by 96 publications

References 9 publications

Sporicidal Activity of Synthetic Antifungal Undecapeptides and Control of Penicillium Rot of Apples

Sporicidal Activity of Synthetic Antifungal Undecapeptides and Control of Penicillium Rot of Apples

Inactivation of Geobacillus stearothermophilus spores by alkaline hydrolysis applied to medical waste treatment

Clinically Relevant Chromosomally Encoded Multidrug Resistance Efflux Pumps in Bacteria

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