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Vila Real de Santo António, Portugal

Monteiro R.,Royal University | Hebraud M.,French National Institute for Agricultural Research | Chafsey I.,French National Institute for Agricultural Research | Chambon C.,French National Institute for Agricultural Research | And 6 more authors.
Biochemistry and Biophysics Reports | Year: 2015

For many years Staphylococcus aureus has been recognized as an important human pathogen. In this study, the surfacome and exoproteome of a clinical sample of MRSA was analyzed. The C2355 strain, previously typed as ST398 and spa-t011 and showing a phenotype of multiresistance to antibiotics, has several resistance genes. Using shotgun proteomics and bioinformatics tools, 236 proteins were identified in the surfaceome and 99 proteins in the exoproteome. Although many of these proteins are related to basic cell functions, some are related to virulence and pathogenicity like catalase and isdA, main actors in S. aureus infection, and others are related to antibiotic action or eventually resistance like penicillin binding protein, a cell-wall protein. Studying the proteomes of different subcellular compartments should improve our understanding of this pathogen, a microorganism with several mechanisms of resistance and pathogenicity, and provide valuable data for bioinformatics databases. © 2015 The Authors. Source


Goncalves A.,Royal University | Goncalves A.,Center for Animal Science and Veterinary | Igrejas G.,Royal University | Radhouani H.,Royal University | And 16 more authors.
Letters in Applied Microbiology | Year: 2013

The aim of this study was to report the antimicrobial resistance, the molecular mechanisms associated and the detection of virulence determinants within faecal Enterococcus spp. and Escherichia coli isolates of Iberian wolf. Enterococci (n = 227) and E. coli (n = 195) isolates were obtained from faecal samples of Iberian wolf (Canis lupus signatus). High rates of resistance were detected for tetracycline and erythromycin among the enterococci isolates, and most of resistant isolates harboured the tet(M) and/or tet(L) and erm(B) genes, respectively. The blaTEM, tet(A) and/or tet(B), and aadA or strA-strB genes were detected among most ampicillin-, tetracycline- or streptomycin-resistant E. coli isolates, respectively. E. coli isolates were ascribed to phylogroups A (n = 56), B1 (91), B2 (13) and D (35). The occurrence of resistant enterococci and E. coli isolates in the faecal flora of Iberian wolf, including the presence of resistant genes in integrons, and virulence determinants was showed in this study. Iberian wolf might act as reservoir of certain resistance genes that could be spread throughout the environment. © 2013 The Society for Applied Microbiology. Source


Goncalves A.,Royal University | Goncalves A.,Center for Animal Science and Veterinary | Poeta P.,Center for Animal Science and Veterinary | Poeta P.,Royal University | And 13 more authors.
Journal of Proteomics | Year: 2014

The Iberian wolf ( Canis lupus signatus) is an endangered species native to the Iberian Peninsula. Due to their predatory and wild nature, these wolves serve as important indicators of environmental contamination by antimicrobial-resistant bacteria. β-Lactam antibiotics like cefotaxime are the most commonly used antibacterial agents. Bacterial resistance to these antibiotics occurs predominantly through enzymatic inactivation by extended-spectrum beta-lactamases. Escherichia coli strain WA57, isolated from Iberian wolf feces, is a cefotaxime-resistant strain that produces extended-spectrum beta-lactamases. In this study, using 2D-GE combined with MS and bioinformatics, we report significant differences in the abundance of 40 protein spots (p. <. 0.01) from the extracellular, periplasmic, cytoplasmic, and membrane sub-proteomes and the whole-cell proteome of WA57 exposed and non-exposed to cefotaxime. A total of 315 protein spots were collected for protein identification. The comparative proteomics presented gives an overview of the complex changes in expression and metabolism that occur when WA57 is stressed with cefotaxime. Abundance of chaperone, porin and export proteins is particularly affected showing that the stress response and transport functions might directly influence the antibiotic resistance of this strain. © 2014 Elsevier B.V. Source


Goncalves A.,Royal University | Goncalves A.,Center for Animal Science and Veterinary | Igrejas G.,Royal University | Radhouani H.,Royal University | And 10 more authors.
Science of the Total Environment | Year: 2011

The aim of this study was to perform the molecular characterization of vancomycin resistant enterococci (VRE) within the faecal flora of Iberian wolf and Iberian lynx. The association with other resistance genes and the detection of virulence genes were also analysed. From 2008 to 2010, 365 faecal samples from Iberian wolf and Iberian lynx were collected and tested for VRE recovery. Mechanisms of resistance to vancomycin and other antibiotics, as well as genes encoding virulence factors were detected through PCR. Multilocus Sequence Typing (MLST) was performed for Enterococcus faecium strains. VRE were recovered in 8 of the 365 analysed samples. The vanA gene was identified in two E. faecium isolates recovered from Iberian wolf faecal samples and the remaining six showed intrinsic resistance (3 vanC1- E. gallinarum and 3 vanC2- E. casseliflavus, from Iberian wolf and Iberian lynx faecal samples, respectively). One vanA. -containing isolate showed tetracycline and erythromycin resistance [with erm(B) and tet(L) genes] and the other one also exhibited ampicillin and kanamycin resistance [with erm(B), tet(M) and aph(3')-III genes]. One of the vanA-isolates revealed a new sequence type named ST573 and the other one belonged to the CC17 clonal complex (ST18). The hyl gene was detected in one E. casseliflavus and three E. gallinarum but not among vanA-positive isolates, and the occurrence of cylA and cylL genes was confirmed in two E. casseliflavus isolates. A low prevalence of VRE has been detected in faecal samples of Iberian wolf and Iberian lynx and strains with an acquired mechanism of resistance to vancomycin have not been detected among Iberian lynx. © 2011 Elsevier B.V. Source


Goncalves A.,Royal University | Goncalves A.,Center for Animal Science and Veterinary | Igrejas G.,Royal University | Radhouani H.,Royal University | And 13 more authors.
Microbial Drug Resistance | Year: 2012

The intensive use of antibiotics in human and veterinary medicine, associated with mechanisms of bacterial genetic transfer, caused a selective pressure that contributed to the dissemination of antimicrobial resistance in different bacteria groups and throughout different ecosystems. Iberian wolf, due to his predatory and wild nature, may serve as an important indicator of environmental contamination with antimicrobial resistant bacteria. The aim of this study was to characterize the diversity of extended-spectrum β-lactamase (ESBL)-producing Escherichia coli isolates within the fecal microbiota of Iberian wolf. Additionally, the identification of other associated resistance genes, phylogenetic groups, and the detection of virulence determinants were also focused on in this study. From 2008 to 2009, 237 fecal samples from Iberian wolf were collected in Portugal. E. coli isolates with TEM-52, SHV-12, CTX-M-1, and CTX-M-14-type ESBLs were detected in 13 of these samples (5.5%). This study reveals the presence of ESBL-producing E. coli isolates, in a wild ecosystem, which could be disseminated through the environment. Moreover, the presence of resistant genes in integrons and the existence of virulence determinants were shown. The association between antibiotic resistance and virulence determinants should be monitored, as it constitutes a serious public health problem. © 2012 Mary Ann Liebert, Inc. Source

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