Project description:The exchange of mobile genomic islands (MGIs) between microorganisms is often mediated by phages. As a consequence, not only phage genes are transferred, but also genes that have no particular function in the phage's lysogenic cycle. If they provide benefits to the phage's host, such genes are referred to as ‘morons’. The present study was aimed at characterizing a set of Enterobacter cloacae, Klebsiella pneumoniae and Escherichia coli isolates with exceptional antibiotic resistance phenotypes from patients in a neonatal ward. Unexpectedly, these analyses unveiled the existence of a novel family of closely related MGIs in Enterobacteriaceae. The respective MGI from E. cloacae was named MIR17-GI. Importantly, our observations show that MIR17-GI-like MGIs harbor genes associated with high-level resistance to cephalosporins. Further, we show that MIR17-GI-like islands are associated with integrated P4-like prophages. This implicates phages in the spread of cephalosporin resistance amongst Enterobacteriaceae. The discovery of a novel family of MGIs spreading ‘cephalosporinase morons’ is of high clinical relevance, because high-level cephalosporin resistance has serious implications for the treatment of patients with Enterobacteriaceal infections.
Project description:Neisseria meningitidis (meningococcus) is usually transmitted via respiratory droplets, whereas its close relative, the gonococcus is sexually transmitted. Invasive meningococcal disease due to isolates of serogroup C increased in Europe and the United States among men who have sex with men (MSM). These isolates were also recovered from cases of urethritis suggesting sexual transmission. Genome sequencing of representative strains revealed that isolates from MSM and urethritis cases belonged to a unique clade within clonal complex11. Proteome analysis showed expression of nitrite reductase by these isolates, enabling anaerobic growth as in gonococci. Invasive isolates from MSM, but not urethritis isolates expressed functional human factor H (hfH) binding protein associated with enhanced survival in transgenic mice expressing hfH, a complement regulatory protein. Our data provide a unique example of meningococcal evolution with adaptation to sexual transmissibility, initially associated with low virulence but with subsequent fHbp-associated invasiveness. Implications for vaccination strategies are discussed.
Project description:The increasing spread of drug-resistant bacterial strains presents great challenges to clinical antibacterial treatment and public health, particularly with regard to β-lactamase-producing Enterobacteriaceae. A rapid and accurate detection method that can expedite precise clinical diagnosis and rational administration of antibiotics is urgently needed.