Project description:Enterobacter cloacae is a Gram-negative nosocomial pathogen of the ESKAPE priority group with increasing multi-drug resistance via the acquisition of resistance plasmids. However, E. cloacae can also display phenotypic antimicrobial resistance, such as heteroresistance or persistence. Here we report that E. cloacae ATCC 13047 and six strains isolated from patients with blood infections display heteroresistance or persistence to aminoglycosides. E. cloacae heteroresistance is transient, accompanied with formation of "petite" colonies and increased MIC against gentamicin and other aminoglycosides used in the clinic, but not other antibiotic classes. To explore the underlying mechanisms, we performed RNA sequencing of heteroresistant bacteria, which revealed global gene-expression changes and a signature of the CpxRA cell envelope stress response. Deletion of the cpxRA two-component system abrogated aminoglycoside heteroresistance and petite colony formation, pointing to its indispensable role in phenotypic resistance. The introduction of a constitutively active allele of cpxA led to high aminoglycoside MICs, consistent with cell envelope stress driving these behaviours in E. cloacae. Cell envelope stress can be caused by environmental cues, including heavy metals. Indeed, bacterial exposure to copper increased gentamicin MIC in the wild type, but not the ΔcpxRA mutant. Moreover, copper exposure also elevated the gentamicin MICs of bloodstream isolates, suggesting that CpxRA- and copper-dependent aminoglycoside resistance is broadly conserved in E. cloacae strains. Altogether, we establish that E. cloacae relies on transcriptional reprogramming via the envelope stress response pathway for transient resistance to a major class of frontline antibiotic.
2023-10-18 | GSE236124 | GEO
Project description:Carriage of mcr-9 and mcr-10 in Enterobacter cloacae complex
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.
2018-08-21 | PXD007113 | Pride
Project description:Serratia marcescens (NDM-1 and non-NDM-1Klebsiella pneumoniae (NDM-1)Enterobacter cloacae (NDM-1) Raw sequence reads
Project description:Recently, we have reported on a highly drug-resistant carbapenemase-producing isolate of Enterobacter cloacae (Nepal et al., Virulence. 2018; 9: 1377-1389). In the present study, we asked the question whether and, if so, how this isolate responds to a sub-inhibitory challenge with the antibiotic imipenem. To answer this question, we applied a SILAC proteomics approach that allowed the quantification of changes in the relative abundance of bacterial protein in response to imipenem. The results show that the investigated E. cloacae isolate mounts a highly specific response to counteract the detrimental effects of imipenem.