Littérature scientifique sur le sujet « Poxa-48 »

AbstractObjectivesThe prevalence of infections caused by OXA-48-like carbapenemase-producing organisms in Ireland has increased dramatically since 2011 and is an urgent public health issue. Genome-based high-resolution genotyping was used to analyse clinical isolates submitted to the Irish Carbapenemase-Producing Enterobacteriaceae Reference Laboratory Service for a 13 month period (2016–17).MethodsA total of 109 OXA-48-producing non-duplicate clinical isolates from 16 submitting centres were sequenced. Using a gene-by-gene approach, isolate genomes were characterized by MLST and core genome MLST, and the presence of antimicrobial resistance determinants was determined. Reference mapping and a novel plasmid MLST-type approach was applied to determine plasmid background.ResultsThe OXA-48-like-producing isolates were Escherichia coli (n = 56), Klebsiella spp. (n = 46) and Enterobacter cloacae (n = 7). Amongst the E. coli isolates there were 37 different STs and amongst the Klebsiella spp. isolates there were 27 different STs. blaOXA-48 was present in 105/109 (96.3%) of isolates. Based on mapping analysis and detection of the pOXA-48 IncL-type plasmid replicon and backbone genes, a pOXA-48-like plasmid was identified in 93/109 isolates (85.3%). The remaining isolates (n = 16; 14.7%) harboured blaOXA-48-like genes in unknown environments. Using a gene-by-gene approach two pOXA-48-like plasmid groups with 2/71 pOXA-48-like locus differences between them were identified.ConclusionsIn Ireland we found a diversity of genotypes associated with OXA-48-like-producing clinical isolates with the IncL pOXA-48 plasmid type predominating as the blaOXA-48 genetic environment. A plasmid MLST approach can rapidly identify plasmids associated with outbreaks and monitor spread of types temporally and geographically.

ABSTRACTComplete sequencing of plasmid pOXA-48a carrying theblaOXA-48gene from aKlebsiella pneumoniaeisolate was performed. Its backbone corresponded to that of an IncL/M-type plasmid, in which theblaOXA-48gene had been integrated through the acquisition of the Tn1999composite transposon without any other antibiotic resistance gene. Molecular epidemiology using a collection of international OXA-48 producers revealed the wide diffusion of pOXA-48a or closely related plasmids.

Abstract Objectives Carbapenemase-producing Enterobacterales (CPE) are increasingly recognized in nosocomial infections, also affecting ICU patients. We aimed to characterize the carbapenemase-producing Serratia marcescens (CPSm) isolates recovered in our hospital in Madrid (Spain) between March 2016 and December 2018. Methods Overall, 50 isolates from clinical and epidemiological surveillance samples were recovered from 24 patients admitted to the medical ICU and 10 non-ICU-related patients based on their phenotypic resistance. Carbapenemase characterization, antibiotic susceptibility, PFGE clonal relatedness, plasmid characterization, WGS (Illumina-NovaSeq 6000) and phylogenetic analysis were performed. Results A single isolate was finally considered for each patient, except for Patient 8 that was colonized by two different isolates (n = 35). Isolates were characterized as VIM-1 (n = 29) or OXA-48 producers (n = 6). Up to seven genetic lineages were found by PFGE, with dominance of two clones. Plasmid characterization confirmed that almost all CPSm carried the same ∼60 kb IncL OXA-48- or VIM-1-encoding plasmid, which was related to the globally disseminated IncL-pOXA-48a. WGS allowed plasmid reconstruction with two variants: IncL-pVIM-1 (∼65 kb) and IncL-pOXA-48 (∼62 kb). blaOXA-48–Tn1999 (∼5 kb) was the unique antibiotic resistance gene in pOXA-48, whereas pVIM-1 plasmids (∼8 kb) harboured a class 1 integron containing 5′-blaVIM-1+aacA4+dfrB1+aadA1+catB2+qacEDelta1+sul1-3′. Conclusions Our results confirm the dissemination of CPSm within our institution in both ICU and non-ICU environments, representing two prevalent CPSm clones, and the same IncL-pOXA-48 plasmid previously described in other Enterobacterales, but containing the blaVIM-1 gene. This also reinforces the relevance of species different from Klebsiella pneumoniae or Escherichia coli in the CPE landscape and circulating lineages and plasmids in local CPE epidemiology.

ABSTRACTThe current emergence of the carbapenemase OXA-48 amongEnterobacteriaceaeis related to the spread of a single IncL/M-type plasmid, pOXA-48a. This plasmid harbors theblaOXA-48gene within a composite transposon, Tn1999, which is inserted into thetirgene, encoding a transfer inhibition protein. We showed that the insertion of Tn1999into thetirgene was involved in a higher transfer frequency of plasmid pOXA-48a. This may likely be the key factor for the successful dissemination of this plasmid.

Resistance to carbapenems is a severe threat to human health. These last resort antimicrobials are indispensable for the treatment of severe human infections with multidrug-resistant Gram-negative bacteria. In accordance with their increasing medical impact, carbapenemase-producing Enterobacteriaceae (CPE) might be disseminated from colonized humans to non-human reservoirs (i.e., environment, animals, food). In Germany, the occurrence of CPE in livestock and food has been systematically monitored since 2016. In the 2019 monitoring, an OXA-48-producing E. coli (19-AB01443) was recovered from a fecal sample of a fattening pig. Phenotypic resistance was confirmed by broth microdilution and further characterized by PFGE, conjugation, and combined short-/long-read whole genome sequencing. This is the first detection of this resistance determinant in samples from German meat production. Molecular characterization and whole-genome sequencing revealed that the blaOXA-48 gene was located on a common pOXA-48 plasmid-prototype. This plasmid-type seems to be globally distributed among various bacterial species, but it was frequently associated with clinical Klebsiella spp. isolates. Currently, the route of introduction of this plasmid/isolate combination into the German pig production is unknown. We speculate that due to its strong correlation with human isolates a transmission from humans to livestock has occurred.

Carbapenem-resistant Klebsiella pneumoniae (CRKP) is a common nosocomial pathogen causing severe infectious diseases, and ST307 CRKP is an emerging clone. In this study, we collected five ST307 CRKP isolates, evaluated their antimicrobial susceptibility using microbroth dilution, and their clonality and population structure by PFGE, cgMLST, and SNP-based phylogenetic analysis. Then, the genome characteristics, such as antimicrobial resistance genes and plasmid profiles, were studied by subsequent genomic analysis. The plasmid transfer ability was evaluated by conjugation, and the carbapenem resistance mechanism was elucidated by gene cloning. The results showed that all five ST307 CRKP isolates harboured blaCMY-6, blaOXA-48, and blaNDM-1; however, the end of the blaNDM-1 signal peptide was interrupted and truncated by an IS10 element, resulting in the deactivation of carbapenemase. The ST307 isolates were closely related, and belonged to the globally disseminated clade. blaOXA-48 and blaNDM-1 were located on the different mobilisable IncL/M- and IncA/C2-type plasmids, respectively, and either the pOXA-48 or pNDM-1 transconjugants were ertapenem resistant. Gene cloning showed that blaCMY-6 could elevate the MICs of carbapenems up to 64-fold and was located on the same plasmid as blaNDM-1. In summary, ST307 is a high-risk clone type, and its prevalence should be given additional attention.

Molecular and genomic surveillance systems for bacterial pathogens currently rely on tracking clonally evolving lineages. By contrast, plasmids are usually excluded or analyzed with low-resolution techniques, despite being the primary vectors of antibiotic resistance genes across many key pathogens. Here, we used a combination of long- and short-read sequence data of Klebsiella pneumoniae isolates (n = 1,717) from a European survey to perform an integrated, continent-wide study of chromosomal and plasmid diversity. This revealed three contrasting modes of dissemination used by carbapenemase genes, which confer resistance to last-line carbapenems. First, blaOXA-48-like genes have spread primarily via the single epidemic pOXA-48–like plasmid, which emerged recently in clinical settings and spread rapidly to numerous lineages. Second, blaVIM and blaNDM genes have spread via transient associations of many diverse plasmids with numerous lineages. Third, blaKPC genes have transmitted predominantly by stable association with one successful clonal lineage (ST258/512) yet have been mobilized among diverse plasmids within this lineage. We show that these plasmids, which include pKpQIL-like and IncX3 plasmids, have a long association (and are coevolving) with the lineage, although frequent recombination and rearrangement events between them have led to a complex array of mosaic plasmids carrying blaKPC. Taken altogether, these results reveal the diverse trajectories of antibiotic resistance genes in clinical settings, summarized as using one plasmid/multiple lineages, multiple plasmids/multiple lineages, and multiple plasmids/one lineage. Our study provides a framework for the much needed incorporation of plasmid data into genomic surveillance systems, an essential step toward a more comprehensive understanding of resistance spread.

Abstract Background The molecular epidemiology of carbapenem-resistant Klebsiella species is not well investigated in Qatar. The objective of this work was to characterize the genetic context of carbapenemase-producing Klebsiella isolates recovered from clinical specimens. Methods Klebsiella isolates (n=100) were collected at 7 tertiary hospitals from 2015-2017. Identification and susceptibility testing were performed using MALDI-TOF MS and BD Phoenix system, respectively. Whole Genome Sequencing was performed on the Illumina NextSeq platform. Phylogenomic analysis, screening of resistance and virulence genes, and comparison of genetic environment of carbapenemase were carried out. Results Klebsiella pneumoniae was common (80), followed by K. quasipneumoniae (16), K. aerogenes (3) and K. oxytoca (1). The most prevalent were genes encoding NDM-1 (39), OXA-48 (20), OXA-232 (10) and OXA-181 (12). KPC-2 (3) and KPC-3 (2) were also identified; no carbapenemase-encoding genes could be identified in 15 isolates. Plasmid locations of 24 carbapenemase-encoding genes were determined; blaNDM-1 was localized on IncFII replicon, while blaOXA-181 and blaOXA-232 were commonly associated with ColKP3 plasmids. pOXA-48-like plasmid was detected in 17/20 isolates harboring blaOXA-48. blaKPC-3 was located on a contig with ‘traditional’ Tn4401a mobile genetic element. Sequence types (STs) were diverse and the ‘traditional’ clonal group (CG) 258 was rare. K. pneumoniae ST147 was predominant (13), followed by ST231 (7) and ST11 (5). Nine K. quasipneumoniae isolates belonged to ST196 and were highly clonal. The virulence loci such as yersiniabactin (ybt) and rmpA were not detected within the study’s K. quasipneumoniae isolates. Amongst K. pneumoniae, there were 50 ybt+ isolates; 8 isolates had rmpA, and of these, 3 belonged to ST383. K. pneumoniae serotype K2, the capsular serotype associated with invasive liver abscess syndrome, was detected in 5 isolates. Genetic relationship of carbapenem-resistant Klebsiella pneumoniae and K. quasipneumoniae isolates in Qatar inferred from core genome SNPs. The tree is overlaid with predicted antimicrobial resistance genes and virulence factors for each isolate. Conclusion The predominant carbapenemases among clinical Klebsiella species isolates in Qatar are NDM and OXA-48 like enzymes, disseminated through various plasmids. The detection of carbapenemase-producing isolate bearing rmpA and serotype K2 reflect the presence of both multidrug resistance and hypervirulence in K. pneumoniae. Disclosures Yohei Doi, MD, PhD, AstraZeneca (Speaker’s Bureau)bioMerieux (Consultant)FujiFilm (Advisor or Review Panel member, Speaker’s Bureau)Gilead (Consultant)GSK (Consultant)Meiji (Consultant)MSD (Consultant)Shionogi (Consultant) Yohei Doi, MD, PhD, Astellas (Individual(s) Involved: Self): Grant/Research Support; AstraZeneca (Individual(s) Involved: Self): Speakers’ bureau; bioMerieux (Individual(s) Involved: Self): Consultant, Speakers’ bureau; Chugai (Individual(s) Involved: Self): Consultant; Entasis (Individual(s) Involved: Self): Consultant; FujiFilm (Individual(s) Involved: Self): Advisor or Review Panel member; Gilead (Individual(s) Involved: Self): Consultant; GSK (Individual(s) Involved: Self): Consultant; Kanto Chemical (Individual(s) Involved: Self): Grant/Research Support; MSD (Individual(s) Involved: Self): Speaking Fee; Pfizer (Individual(s) Involved: Self): Grant/Research Support; Shionogi (Individual(s) Involved: Self): Grant/Research Support, Speakers’ bureau; Teijin Healthcare (Individual(s) Involved: Self): Speakers’ bureau; VenatoRx (Individual(s) Involved: Self): Consultant

Carbapenem-hydrolysing enzymes belonging to the OXA-48-like group are encoded by bla OXA-48-like alleles and are abundant among Enterobacterales in the Netherlands. Therefore, the objective here was to investigate the characteristics, gene content and diversity of the bla OXA-48-like carrying plasmids and chromosomes of Escherichia coli and Klebsiella pneumoniae collected in the Dutch national surveillance from 2014 to 2019 in comparison with genome sequences from 29 countries. A combination of short-read genome sequencing with long-read sequencing enabled the reconstruction of 47 and 132 complete bla OXA-48-like plasmids for E. coli and K. pneumoniae , respectively. Seven distinct plasmid groups designated as pOXA-48-1 to pOXA-48-5, pOXA-181 and pOXA-232 were identified in the Netherlands which were similar to internationally reported plasmids obtained from countries from North and South America, Europe, Asia and Oceania. The seven plasmid groups varied in size, G+C content, presence of antibiotic resistance genes, replicon family and gene content. The pOXA-48-1 to pOXA-48-5 plasmids were variable, and the pOXA-181 and pOXA-232 plasmids were conserved. The pOXA-48-1, pOXA-48-2, pOXA-48-3 and pOXA-48-5 groups contained a putative conjugation system, but this was absent in the pOXA-48-4, pOXA-181 and pOXA-232 plasmid groups. pOXA-48 plasmids contained the PemI antitoxin, while the pOXA-181 and pOXA-232 plasmids did not. Furthermore, the pOXA-181 plasmids carried a virB2-virB3-virB9-virB10-virB11 type IV secretion system, while the pOXA-48 plasmids and pOXA-232 lacked this system. A group of non-related pOXA-48 plasmids from the Netherlands contained different resistance genes, non-IncL-type replicons or no replicons. Whole genome multilocus sequence typing revealed that the bla OXA-48-like plasmids were found in a wide variety of genetic backgrounds in contrast to chromosomally encoded bla OXA-48-like alleles. Chromosomally localized bla OXA-48 and bla OXA-244 alleles were located on genetic elements of variable sizes and comprised regions of pOXA-48 plasmids. The bla OXA-48-like genetic element was flanked by a direct repeat upstream of IS1R, and was found at multiple locations in the chromosomes of E. coli . Lastly, K. pneumoniae isolates carrying bla OXA-48 or bla OXA-232 were mostly resistant for meropenem, whereas E. coli bla OXA-48, bla OXA-181 and chromosomal bla OXA-48 or bla OXA-244 isolates were mostly sensitive. In conclusion, the overall bla OXA-48-like plasmid population in the Netherlands is conserved and similar to that reported for other countries, confirming global dissemination of bla OXA-48-like plasmids. Variations in size, presence of antibiotic resistance genes and gene content impacted pOXA-48, pOXA-181 and pOXA-232 plasmid architecture.

ABSTRACT The aim of this study was to characterize the first cases and outbreaks of OXA-48-like-producing Enterobacteriaceae recovered from hospital settings in the Czech Republic. From 2013 to 2015, 22 Klebsiella pneumoniae isolates, 3 Escherichia coli isolates, and 1 Enterobacter cloacae isolate producing OXA-48-like carbapenemases were isolated from 20 patients. Four of the patients were colonized or infected by two or three different OXA-48-like producers. The K. pneumoniae isolates were classified into nine sequence types (STs), with ST101 being predominant (n = 8). The E. coli isolates were of different STs, while the E. cloacae isolate belonged to ST109. Twenty-four isolates carried bla OXA-48, while two isolates carried bla OXA-181 or bla OXA-232. Almost all isolates (n = 22) carried bla OXA-48-positive plasmids of a similar size (∼60 kb), except the two isolates producing OXA-181 or OXA-232. In an ST45 K. pneumoniae isolate and an ST38 E. coli isolate, S1 nuclease profiling plus hybridization indicated a chromosomal location of bla OXA-48. Sequencing showed that the majority of bla OXA-48-carrying plasmids exhibited high degrees of identity with the pOXA-48-like plasmid pE71T. Additionally, two novel pE71T derivatives, pOXA-48_30715 and pOXA-48_30891, were observed. The bla OXA-181-carrying plasmid was identical to the IncX3 plasmid pOXA181_EC14828, while the bla OXA-232-carrying plasmid was a ColE2-type plasmid, being a novel derivative of pOXA-232. Finally, sequencing data showed that the ST45 K. pneumoniae and ST38 E. coli isolates harbored the IS1R-based composite transposon Tn6237 containing bla OXA-48 integrated into their chromosomes. These findings underlined that the horizontal transfer of pOXA-48-like plasmids has played a major role in the dissemination of bla OXA-48 in the Czech Republic. In combination with the difficulties with their detection, OXA-48 producers constitute an important public threat.