Growth in glucose-based medium and exposure to subinhibitory concentrations of imipenem induce biofilm formation in a multidrug-resistant clinical isolate of Acinetobacter baumannii
Rattachement africain : it. Niveau de preuve : code pays fourni par la source.
Le résumé fourni par la source
BACKGROUND: Acinetobacter baumannii is emerging as an important nosocomial pathogen. Multidrug resistance, as well as ability to withstand environmental stresses, makes eradication of A. baumannii difficult, particularly from hospital settings. RESULTS: Over a six-year period, 73 isolates of A. baumannii were collected from infected patients in two hospitals in Italy. While 69 out of the 73 isolates displayed identical multidrug antibiotic resistance pattern, they were susceptible to carbapenems. Genetic profiles of these 69 isolates, determined by Pulsed Field Gel Electrophoresis (PFGE), indicated that they were genetically related and could be clustered in a specific clone, called SMAL. We tested the ability of the SMAL clone to form biofilm, an important determinant for bacterial colonization of the human host and for persistence in the hospital environment. Biofilm formation by A. baumannii SMAL, measured as surface adhesion to polystyrene, is strongly affected by growth conditions, being impaired in rich growth media such as LB, while being favoured in glucose-based medium. Surface adhesion in glucose-based media is inhibited by treatment with cellulase, suggesting that it depends on production of cellulose or of a chemically related extracellular polysaccharide. Exposure of A. baumannii SMAL to subinhibitory concentrations of imipenem resulted in biofilm stimulation and increased production of iron uptake proteins. Growth in iron-supplemented medium also stimulated surface adhesion, thus suggesting that increased intracellular iron concentrations might act as an environmental signal for biofilm formation in A. baumannii SMAL. CONCLUSIONS: Our results indicate that exposure to subinhibitory concentrations of imipenem can stimulate biofilm formation and induce iron uptake in a pathogenic strain of A. baumannii, with potential implications on antibiotic susceptibility and ability to persist in the human host.
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Le contrôle bibliographique ouvert
DOI retrouvé dans Crossref DOI retrouvé ; titre concordant.
- Titre Crossref
- Growth in glucose-based medium and exposure to subinhibitory concentrations of imipenem induce biofilm formation in a multidrug-resistant clinical isolate of Acinetobacter baumannii
- Date Crossref
- 01/12/2009
- Éditeur
- Springer Science and Business Media LLC
- Type
- journal-article
Ce recoupement confirme des métadonnées liées au DOI. Il ne confirme ni la méthode ni les conclusions de l’étude, et il ne compte pas comme une seconde source scientifique indépendante.
Où se fait cette recherche
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University of Milan pays non établi dans la noticeUniversité ou école supérieure
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University of Pavia pays non établi dans la noticeUniversité ou école supérieure
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Policlinico San Matteo Fondazione pays non établi dans la noticeÉtablissement de santé
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Istituti di Ricovero e Cura a Carattere Scientifico pays non établi dans la noticeÉtablissement de santé
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Fondazione Salvatore Maugeri pays non établi dans la noticeOrganisation à but non lucratif
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Department of Biomolecular Sciences and Biotechnology pays non établi dans la noticeInstitution
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Eidological and Clinical Sciences Department of Morphological pays non établi dans la noticeÉtablissement de santé
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Microbiological Analysis Laboratory pays non établi dans la noticeStructure de recherche
University of Milan, University of Pavia et Policlinico San Matteo Fondazione, avec 5 autres affiliations.
Une affiliation ne permet pas de déduire la nationalité d’un auteur.