François Malouin

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The intramammary colonisation by Staphylococcus aureus provokes mastitis in the cow. Once established, the infection is difficult to eradicate with available therapies and may become chronic. The present article focuses on the use of the experimental mouse model of S. aureus-induced mastitis as a practical approach for the study of bovine mastitis. Results(More)
Staphylococcus aureus small-colony variants (SCVs) are believed to account in part for the persistence of S. aureus during chronic infections. Little is understood about the gene expression profile that may explain the phenotype and distinguish SCVs from prototype S. aureus strains. In this study, DNA array transcriptional profiles of clinical SCVs isolated(More)
To protect themselves, plants accumulate an armoury of antimicrobial secondary metabolites. Some metabolites represent constitutive chemical barriers to microbial attack (phytoanticipins) and others inducible antimicrobials (phytoalexins). They are extensively studied as promising plant and human disease-controlling agents. This review discusses the(More)
Staphylococcus aureus is an important pathogen that is responsible for a wide range of infections, including bovine mastitis. Previously, 54 genes from S. aureus that were up-regulated in an iron-restricted medium and in mice were identified. Seven of those genes were selected from five iron-acquisition systems (isd, feo, sir, sst, and fhu), and the(More)
Genes encoding cell-surface proteins regulated by SigB are stably expressed in Staphylococcus aureus small-colony variants (SCVs) isolated from cystic fibrosis (CF) patients. Our hypothesis is that CF-isolated SCVs are locked into a colonization state by sustaining the expression of adhesins such as fibronectin-binding proteins (FnBPs) throughout growth.(More)
Staphylococcus aureus and Pseudomonas aeruginosa are often found together in the airways of cystic fibrosis (CF) patients. It was previously shown that the P. aeruginosa exoproduct 4-hydroxy-2-heptylquinoline-N- oxide (HQNO) suppresses the growth of S. aureus and provokes the emergence of small-colony variants (SCVs). The presence of S. aureus SCVs as well(More)
Staphylococcus aureus is a common cause of bovine mastitis and foodborne and other diseases in humans. This study tested the hypothesis that small colony variants (SCVs) of S. aureus are implicated in chronic bovine mastitis. Six S. aureus isolates from foremilk samples from 11 chronically infected cows were investigated. Five isolates had typical(More)
RWJ-54428 (MC-02,479) is a new cephalosporin active against gram-positive bacteria, including methicillin-resistant Staphylococcus aureus (MRSA). The potency of this new cephalosporin against MRSA is related to a high affinity for penicillin-binding protein 2a (PBP 2a), as assessed in a competition assay using biotinylated ampicillin as the reporter(More)
Staphylococcus aureus small-colony variants (SCVs) and biofilms are linked to chronic infections. It is known that the presence of aminoglycoside antibiotics may contribute to the emergence of SCVs and it is thought that molecular mechanisms are involved in the ability of S. aureus to adopt this phenotype. No study has addressed the possible role of the(More)
OBJECTIVES This study evaluated the affinity of ceftaroline and comparator beta-lactams for penicillin-binding proteins (PBPs) of methicillin-susceptible Staphylococcus aureus (MSSA), methicillin-resistant S. aureus (MRSA) and Streptococcus pneumoniae with varying susceptibility to penicillin. Ceftaroline is currently in Phase 3 development for the(More)