Project description:Objectives. A large OXA-48 outbreak in the Netherlands involved the spread of OXA-48producing Enterobacteriaceae among at least 118 patients, suggesting horizontal transfer of this resistance gene through one or more plasmids. Elucidating transmission dynamics of resistance plasmids is hampered by the low resolution of classic typing methods. This study aimed to investigate the molecular epidemiology of plasmids carrying OXA-48 carbapenemase using a next-generation sequencing approach.Methods. A total of 68 OXA-48-producing Enterobacteriaceae isolated from the hospital outbreak, as well as 22 non-outbreak related OXA-48-producing Enterobacteriaceae from the Netherlands, Libya and Turkey were selected. Plasmids were sequenced using the Illumina Miseq platform, and read sets were assembled and analysed.Results. In all plasmids blaOXA-48 was embedded in transposon Tn1999.2 and located on a ca. 62 kb IncL/M conjugative plasmid in 14 different species. There were a maximum of 2 SNPs (single nucleotide polymorphisms) between the core sequence alignment of all plasmids. Closely related sequence variants of this plasmid were detected in non-outbreak isolates from the Netherlands and other countries. Thirty-one of 89 OXA-48-producing isolates also harboured blaCTX-M-15, which was not located on the blaOXA-48-carrying plasmid. Sequencing of four plasmids harbouring blaCTX-M15 revealed extensive plasmid heterogeneity.Conclusions. A ca 62 kb plasmid was responsible for the OXA-48 outbreak in a Dutch hospital. Our findings provide strong evidence for both within-host inter-species and between host dissemination of plasmid-based OXA-48 during a nosocomial outbreak. These findings exemplify the complex epidemiology of carbapenemase producing Enterobacteriaceae (CPE).
Project description:Multidrug-resistant (MDR) Enterobacterales remain an increasing problem in Algeria, notably due to the emergence of carbapenemase producers. We investigated the molecular characteristics of carbapenem-resistant Enterobacterales isolates recovered from outpatients and inpatients in Eastern Algeria. Non-repetitive Enterobacterales with reduced susceptibility to carbapenems were consecutively collected from clinical specimens in Annaba University Hospital (Algeria) between April 2016 and December 2018. Isolates were characterized with regard to antibiotic resistance, resistome and virulome content, clonality, and plasmid support. Of the 168 isolates analyzed, 29 (17.3%) were carbapenemase producers and identified as K. pneumoniae (n = 23), E. coli (n = 5), and E. cloacae (n = 1). blaOXA-48 was the most prevalent carbapenemase-encoding gene (n = 26/29), followed by blaNDM-1 gene (n = 3/29). K. pneumoniae isolates harbored some virulence traits (entB, ugeF, ureA, mrkD, fimH), whereas E. coli had a commensal origin (E, A, and B1). Clonality analysis revealed clonal expansions of ST101 K. pneumoniae and ST758 E. coli. Plasmid analysis showed a large diversity of incompatibility groups, with a predominance of IncM (n = 26, 89.7%). A global dissemination of OXA-48-producing Enterobacterales in the Algerian hospital but also the detection of NDM-1-producing E. coli in community settings were observed. The importance of this diffusion must be absolutely investigated and controlled.
Project description:Purpose: The goal of this study was to elucidate the collateral effects associated with OXA-23 overexpression on the Acinetobacter baumannii global transcriptome. Results: Besides the 99.73-fold increase in blaOXA-23 transcript upon IPTG induction, no other transcripts showed more than a 2-fold change compared to the wildtype control. This suggests that OXA-23 over expression to levels similarly observed in multi drug resistant A. baumannii clinical isolates does not effect the transcriptome.