Triclosan-tolerant bacteria: changes in susceptibility to antibiotics.

Faculty of Health and Medical Science, University of Surrey, Surrey, UK.
The Journal of hospital infection (Impact Factor: 3.01). 03/2009; 72(1):71-6. DOI: 10.1016/j.jhin.2009.01.014
Source: PubMed

ABSTRACT There is no clear consensus regarding the effect of biocide tolerance on antibiotic susceptibility. In this work, triclosan-tolerant strains of Escherichia coli, Staphylococcus aureus and Acinetobacter johnsonii were compared with sensitive strains in order to ascertain their susceptibility to a range of antibiotics. The minimum inhibitory concentrations of triclosan were measured using broth- and agar-dilution techniques. Antibiotic susceptibilities were determined using the British Society for Antimicrobial Chemotherapy guidelines. No triclosan-tolerant strains were resistant to antibiotics, and there was no overall tendency for triclosan-tolerant strains to have significantly smaller zones of inhibition compared with counterpart strains. Triclosan-tolerant strains of E. coli were significantly more susceptible to aminoglycoside antibiotics. The mechanism by which E. coli develops tolerance to triclosan appears to be linked to aminoglycoside susceptibility. It is proposed that changes in outer membrane, or the loss of plasmids, may be responsible for this relationship.

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    ABSTRACT: Objective The aim of this study is to obtain a better understanding regarding the origin of recurrent contamination by Enterobacter gergoviae in diverse cosmetics formula. We studied 65 isolates collected from various sources (clinical, food, cosmetics).MethodsRAPD analysis using AP12H, REP and ERIC-PCR were carried out for epidemiological typing. Evaluation of susceptibility to preservatives currently used in cosmetics for a representative panel of collection strains was measured. Preservatives efficacy and involvement of the pH were evaluated by MICs and MBCs.Results80% of isolates was unrelated. E. gergoviae showed significant levels of resistance to preservatives. MIC and MBC were higher than concentration recommended by cosmetics industry (CI) and European commission (EC). Variation in pH reduced the efficacy of preservatives. Association of preservatives showed in rare case additive effects, no synergic effects were observed.Conclusion Most of the cosmetic formulations are contaminated with unrelated E. gergoviae strains. Recommended concentrations are inefficient to limit proliferation and control adaptability to this bacterium in cosmetics products. Efflux mechanisms should be involved in Kathon cg and Irgasan adaptation.This article is protected by copyright. All rights reserved.
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    ABSTRACT: Salmonella sp. continues to be one of the most important foodborne pathogens. Control measures in terms of cleaning and disinfection on food production plants are very important for limiting the risk of contaminated food products to reach the consumer. In the last decade concern has arisen that bacteria exposed to disinfectants can develop resistance toward disinfectants and can have a higher risk of developing antibiotic resistance. The objectives of this study were to examine the prevalence of biocide resistant Salmonella sp. in Danish pig slaughterhouses, to evaluate if there was a correlation between susceptibilities to biocides and antibiotics, and to examine if cleaning and disinfection select isolates with changed susceptibility toward biocides or antibiotics. Salmonella sp. was isolated from the environment in Danish pig slaughterhouses before and after cleaning and disinfection. The susceptibility toward three different biocides, triclosan and two commercial disinfection products: Desinfect Maxi, a quaternary ammonium compound, and Incimaxx DES, an acetic compound, was determined. We found no resistance toward the biocides tested, but we did find that isolates obtained after cleaning had higher minimum inhibitory concentration (MIC) values toward one of the disinfectants (Incimaxx DES) compared to isolates obtained before cleaning and disinfection. This could indicate selection of strains that are more tolerant, due to the cleaning and disinfection. Furthermore, we found that there was a weak statistical correlation between MICs toward the biocides and some antibiotics, but no difference in log(MIC)s toward antibiotics between isolates obtained before and after cleaning, nor did we find any difference in the number of resistances of isolates obtained before and after cleaning and disinfection.
    International journal of food microbiology 04/2014; 181C:53-59. · 3.01 Impact Factor
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    Biotechnology and Bioprocess Engineering 06/2014; 19(3):526-533. · 1.28 Impact Factor

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