amylovora strains with the European strain CFBP1430 and North-American strain ATCC49946. Analysis of single nucleotide polymorphisms (SNPs) revealed genetic homogeneity

of Moroccan’s strains and their proximity to the European strain CFBP1430. Moreover, the collected sequences allowed the assembly of a 65 kpb plasmid, which is highly similar to the plasmid pEI70 harbored by several European E. amylovora isolates. This plasmid was found in 33% of the 40 E. amylovora strains collected from several host plants in 2009 and 2010 in Morocco. (C) 2013 Institut Pasteur. Published by Elsevier Masson SAS. All rights reserved.”
“In this study, we identified an antimicrobial compound produced by the Gram-negative bacterium Serratia marcescens. Colonies of S. marcescens inhibited the growth of nine different methicillin-resistant Staphylococcus aureus (MRSA) isolates and several other tested Gram-positive bacterial 4SC-202 in vitro species, but not Gram-negative bacteria. Genetic analysis revealed the CAL-101 solubility dmso requirement for the swrW gene which codes for a non-ribosomal peptide synthetase that generates the cyclodepsipeptide antibiotic serratamolide, also known

as serrawettin W1. This is the first report describing the anti-MRSA properties of serratamolide. (C) 2013 Institut Pasteur. Published by Elsevier Masson SAS. All rights reserved.”
“Bartonella henselae is a zoonotic pathogen that possesses a flea-cat-flea transmission cycle and causes cat scratch disease in humans via cat scratches and bites. In order to establish infection, B. NU7026 henselae must overcome oxidative stress damage produced by the mammalian host and arthropod vector. B. henselae encodes for putative Fe2+ and Mn2+ transporter SitABCD. In B. henselae, SitAB knockdown increases sensitivity to hydrogen peroxide. We consistently show that SitAB knockdown decreases the ability of B. henselae to survive in both human endothelial cells

and cat fleas, thus demonstrating that the SitABCD transporter plays an important role during the B. henselae infection cycle. (C) 2013 Institut Pasteur. Published by Elsevier Masson SAS. All rights reserved.”
“The alternative sigma factor RpoS is a central regulator of the stress response in many Proteobacteria, acting both during exponential growth and in stationary phase. The small protein Crl increases the interaction between RpoS and RNA polymerase and thereby activates certain RpoS-dependent promoters. However, the growth-phase dependence of the interaction of Crl with different forms of polymerase remains unknown. We use 41 GFP transcriptional fusions to study the dynamics of gene regulation by RpoS and Crl during growth transition from exponential to stationary phase in Escherichia coli. We confirm that RpoS can regulate gene expression in exponential phase, both positively and negatively. Crl slightly stimulates transcription by RpoS in exponential phase and controls a subset of RpoS-dependent genes in stationary phase.