In addition, a relationship was demonstrated between the absence of capsule and the incapacity to assign a known serotype to S. suis isolates. We are grateful to K. Kim (Johns Hopkins University School of Medicine) for providing the HBMEC. We wish to thank Sonia Lacouture, Louis Grignon, and Richard Janvier for their technical assistance. This study was supported by the Fond Québécois de la Recherche sur la Nature
BGB324 et les Technologies (FQRNT) and the Natural Sciences and Engineering Research Council of Canada (NSERC). All authors report no conflicts of interest related to their study. “
“In this study, we investigated the β-lactamase-encoding genes responsible for β-lactam resistance phenotypes detected among 56 Gram-negative isolates (Gamma- and Alpha-proteobacteria) recovered PF-2341066 from wastewater, urban streams, and drinking water. The β-lactam resistance mechanisms detected in 36 isolates comprised the presence of class A (blaTEM-1, blaSHV-1, blaSHV-11, blaGES-5), class B (ImiS, L1), class C (blaCMY-2, blaCMY-34, blaCMY-65, blaCMY-89, blaCMY-90, blaACC-5, blaACT-13), and class D (blaOXA-309)β-lactamase-encoding genes, some variants described for the first time here. Notably, the results showed antimicrobial resistance genes related not only to commonly used antibiotics, but also to carbapenems, providing the first
description of a GES-5-producing Enterobacteriaceae. The importance of ubiquitous bacteria thriving in aquatic environments as reservoirs or carriers of clinically relevant resistance determinants was confirmed, and the need to monitor water habitats as potential sources for the emergence and/or spread of antibiotic resistance in the environment was highlighted. “
“Medizinische Fakultät, Klinik für Kinder-Onkologie-Hämatologie und Klinische Immunologie, Heinrich-Heine Universität
Düsseldorf, Düsseldorf, Germany Medizinische Fakultät, Max von Pettenkofer-Institut für Hygiene und Medizinische Mikrobiologie, Ludwig-Maximilians-Universität München, acetylcholine München, Germany The ubiquitous pathogen Listeria monocytogenes lives either saprophytically in the environment or within cells in a vertebrate host, thus adapting its lifestyle to its ecological niche. Growth experiments at 24 and 37 °C (environmental and host temperature) with ammonium or glutamine as nitrogen sources revealed that ammonium is the preferred nitrogen source of L. monocytogenes. Reduced growth on glutamine is more obvious at 24 °C. Global transcriptional microarray analyses showed that the most striking difference in temperature-dependent transcription was observed for central nitrogen metabolism genes, glnR (glutamine synthetase repressor GlnR), glnA (glutamine synthetase GlnA), amtB (ammonium transporter AmtB), glnK (PII regulatory protein GlnK), and gdh (glutamate dehydrogenase) when cells were grown on glutamine.