Ricardo Leon-Sampedro

Last Name

Leon-Sampedro

First Name

Ricardo

ORCID

0000-0001-5317-8310

Organisational unit

03584 - Bonhoeffer, Sebastian / Bonhoeffer, Sebastian

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Publications 1 - 10 of 24

Multi-layered ecological interactions determine growth of clinical antibiotic-resistant strains within human microbiomes
Leon-Sampedro, Ricardo; Boumasmoud, Mathilde; Reichlin , Markus; et al. (2025)
Nature Communications
The spread of antibiotic-resistant bacteria in the gut depends on their ability to establish within complex microbial communities. However, the role of various ecological factors in modulating this process, particularly in the absence of antibiotic selection, remains poorly understood. We hypothesize that different strains within the same species vary in their ability to colonize due to distinct interactions with resident microbiota. Using human gut-microbiome samples in replicated anaerobic microcosms with and without antibiotics, we test multiple clinically relevant and phylogenetically distinct Escherichia coli strains carrying extended-spectrum beta-lactamase (ESBL) or carbapenemase plasmids. While antibiotics influence the growth of incoming resistant strains, some are successful even without antibiotics. Growth outcomes depend on a combination of intrinsic growth capacities in relevant abiotic conditions, competition with resident E. coli, and strain-specific shifts in resident community composition. We also detect horizontal transfer of resistance plasmids in some conditions, but transconjugants remain rare across treatments. Here, we show that the success of antibiotic-resistant bacteria depends on strain-specific ecological interactions, helping to explain the spread and persistence of resistance in human microbiomes.
Clinical antibiotic-resistance plasmids have small effects on biofilm formation and population growth in Escherichia coli in vitro
Brülisauer, Laura; Leon-Sampedro, Ricardo; Hall, Alex R. (2023)
Plasmid
Antimicrobial resistance (AR) mechanisms encoded on plasmids can affect other phenotypic traits in bacteria, including biofilm formation. These effects may be important contributors to the spread of AR and the evolutionary success of plasmids, but it is not yet clear how common such effects are for clinical plasmids/bacteria, and how they vary among different plasmids and host strains. Here, we used a combinatorial approach to test the effects of clinical AR plasmids on biofilm formation and population growth in clinical and laboratory Escherichia coli strains. In most of the 25 plasmid-bacterium combinations tested, we observed no significant change in biofilm formation upon plasmid introduction, contrary to the notion that plasmids frequently alter biofilm formation. In a few cases we detected altered biofilm formation, and these effects were specific to particular plasmid-bacterium combinations. By contrast, we found a relatively strong effect of a chromosomal streptomycin-resistance mutation (in rpsL) on biofilm formation. Further supporting weak and host-strain-dependent effects of clinical plasmids on bacterial phenotypes in the combinations we tested, we found growth costs associated with plasmid carriage (measured in the absence of antibiotics) were moderate and varied among bacterial strains. These findings suggest some key clinical resistance plasmids cause only mild phenotypic disruption to their host bacteria, which may contribute to the persistence of plasmids in the absence of antibiotics.
Outbreak of NDM-1+CTX-M-15+DHA-1-producing Klebsiella pneumoniae high-risk clone in Spain owing to an undetectable colonised patient from Pakistan
Hernández-García, Marta; Pérez-Viso, Blanca; Leon-Sampedro, Ricardo; et al. (2019)
International Journal of Antimicrobial Agents
Here we describe an outbreak due to NDM-1+CTX-M-15+DHA-1-producing Klebsiella pneumoniae (NDM-1-Kp) in Spain related to a patient previously admitted to a healthcare centre in an endemic area (Pakistan). Nine colonised patients were detected in the Neurosurgery ward between September 2015 and February 2016 during the R-GNOSIS European Project. NDM-1-Kp isolates from clinical samples were also recovered in three of these patients. Surveillance culture at admission was negative in the index case, but NDM-1-Kp colonisation was detected 27 days later after receiving antibiotic treatment. Co-colonisation with a second NDM-1-Kp isolate was identified in this patient 61 days post-admission. Overall length of stay (LOS = 75 days) (P < 0.01) and LOS until carbapenemase detection (LOS-1 = 36 days) was longer in NDM-1-Kp carriers than in patients with other carbapenemase-producing Enterobacterales. Intervention strategies were implemented after the outbreak declaration and NDM-1-Kp transmission was contained. Among the NDM-1-Kp isolates, two clones [ST437 (index case and Patient 2) and ST101 (index case and Patients 3-9)] with different IncFIB NDM-1-containing plasmids were identified. Whole-genome sequencing revealed a high content of antimicrobial resistance genes in both isolates in addition to a large number of virulence factors. Colonisation with other epidemic (OXA-48-ST11-K. pneumoniae and VIM-1-ST54-K. pneumoniae) and non-epidemic (VIM-1-ST908-K. pneumoniae and VIM-ST431-Escherichia coli) clones was also detected in two NDM-1 carriers. Implementation of adequate infection control measures and uninterrupted active surveillance programmes for detecting patients with a low colonisation status are crucial to prevent the introduction and dissemination of NDM-type enzymes in our region.
Within-patient evolution of plasmid-mediated antimicrobial resistance
DelaFuente, Javier; Toribio-Celestino, Laura; Santos-Lopez, Alfonso; et al. (2022)
Nature Ecology & Evolution
Antimicrobial resistance (AMR) in bacteria is a major threat to public health; one of the key elements in the spread and evolution of AMR in clinical pathogens is the transfer of conjugative plasmids. The drivers of AMR evolution have been studied extensively in vitro but the evolution of plasmid-mediated AMR in vivo remains poorly explored. Here, we tracked the evolution of the clinically relevant plasmid pOXA-48, which confers resistance to the last-resort antibiotics carbapenems, in a large collection of enterobacterial clones isolated from the gut of hospitalized patients. Combining genomic and experimental approaches, we first characterized plasmid diversity and the genotypic and phenotypic effects of multiple plasmid mutations on a common genetic background. Second, using cutting-edge genomic editing in wild-type multidrug-resistant enterobacteria, we dissected three cases of within-patient plasmid-mediated AMR evolution. Our results revealed compensatory evolution of plasmid-associated fitness cost and the evolution of enhanced plasmid-mediated AMR in bacteria evolving in the gut of hospitalized patients. Crucially, we observed that the evolution of pOXA-48-mediated AMR in vivo involves a pivotal trade-off between resistance levels and bacterial fitness. This study highlights the need to develop new evolution-informed approaches to tackle plasmid-mediated AMR dissemination.
Translational demand is not a major source of plasmid-associated fitness costs
Rodríguez-Beltrán, Jerónimo; Leon-Sampedro, Ricardo; Ramiro-Martínez, Paula; et al. (2022)
Philosophical Transactions of the Royal Society B: Biological Sciences
Plasmids are key drivers of bacterial evolution because they are crucial agents for the horizontal transfer of adaptive traits, such as antibiotic resistance. Most plasmids entail a metabolic burden that reduces the fitness of their host if there is no selection for plasmid-encoded genes. It has been hypothesized that the translational demand imposed by plasmid-encoded genes is a major mechanism driving the fitness cost of plasmids. Plasmid-encoded genes typically present a different codon usage from host chromosomal genes. As a consequence, the translation of plasmid-encoded genes might sequestrate ribosomes on plasmid transcripts, overwhelming the translation machinery of the cell. However, the pervasiveness and origins of the translation-derived costs of plasmids are yet to be assessed. Here, we systematically altered translation efficiency in the host cell to disentangle the fitness effects produced by six natural antibiotic resistance plasmids. We show that limiting translation efficiency either by reducing the number of available ribosomes or their processivity does not increase plasmid costs. Overall, our results suggest that ribosomal paucity is not a major contributor to plasmid fitness costs.
Transfer dynamics of Tn6648, a composite integrative conjugative element generated by tandem accretion of Tn5801 and Tn6647 in Enterococcus faecalis
Leon-Sampedro, Ricardo; Fernández-de-Bobadilla, Miguel D.; San Millán, Álvaro; et al. (2019)
Journal of Antimicrobial Chemotherapy
Background Tn5801 [tet(M)], a Tn916-like element with site-specific affinity for the 3′ end of the housekeeping gene guaA, may integrate at different chromosomal sites. Objectives To characterize the genetic context of Tn5801 to define its transfer dynamics and impact on the evolution of Enterococcus faecalis (Efs). Methods WGS (Illumina HiSeq 2500) was performed on the Efs clinical strain Ef1 and primary and secondary transconjugants of Efs strains JH2-2 [which naturally contains Tn5801.B23, an unusual variant that lacks tet(M)], OG1RF and OG1SS carrying different copies of Tn5801-like elements. The transposon structures were analysed using a range of bioinformatics tools allowing us to identify the context of Tn5801-like elements. Growth rates at different tetracycline concentrations (0.5–20 mg/L) were estimated using a Synergy HTX plate reader. Results Tn5801.B15 [tet(M), 20.3 kb] exists and can be transferred either singly or within Tn6648 (53.2 kb), a composite element that comprises Tn5801.B15 and Tn6647, a newly identified 32.8 kb transposon that contains the prgABCT operon of pheromone-responsive plasmids. These transposons are able to integrate at specific 11 nt sequences at the 3′ end of guaA and at other chromosomal sites in Efs genomes, thus being able to generate tandem accretions. These events may increase the number of tet(M) copies, enhancing tetracycline resistance in the recipient strain. Conclusions This study describes Tn6647 and Tn6648 (comprising Tn6647 and Tn5801.B15) and highlights the diversity of mechanisms for conjugative mobilization and chromosomal insertion of these elements, which can result in tandem accretion. This strategy would facilitate the adaptation of Efs clones to environmental challenges.
Dissemination routes of the carbapenem resistance plasmid pOXA-48 in a hospital setting
Leon-Sampedro, Ricardo; DelaFuente, Javier; Díaz-Agero, Cristina; et al. (2020)
bioRxiv
Infections caused by carbapenemase-producing enterobacteria (CPE) are a major concern in clinical settings worldwide. Two fundamentally different processes shape the epidemiology of CPE in hospitals: the dissemination of CPE clones from patient to patient (between-patient transfer), and the transfer of carbapenemase-encoding plasmids between enterobacteria in the gut microbiota of individual patients (within-patient transfer). The relative contribution of each process to the overall dissemination of carbapenem resistance in hospitals remains poorly understood. Here, we used mechanistic models combining epidemiological data from more than 9,000 patients with whole genome sequence information from 250 enterobacteria clones to characterise the dissemination routes of the carbapenemase-encoding plasmid pOXA-48 in a hospital setting over a two-year period. Our results revealed frequent between-patient transmission of high-risk pOXA-48-carrying clones, mostly of Klebsiella pneumoniae and sporadically Escherichia coli. The results also identified pOXA-48 dissemination hotspots within the hospital, such as specific wards and individual rooms within wards. Using high-resolution plasmid sequence analysis, we uncovered the pervasive within-patient transfer of pOXA-48, suggesting that horizontal plasmid transfer occurs in the gut of virtually every colonised patient. The complex and multifaceted epidemiological scenario exposed by this study provides new insights for the development of intervention strategies to control the in-hospital spread of CPE.
First Report of an OXA-48- and CTX-M-213-Producing Kluyvera Species Clone Recovered from Patients Admitted in a University Hospital in Madrid, Spain
Hernández-García, Marta; Leon-Sampedro, Ricardo; Pérez-Viso, Blanca; et al. (2018)
Antimicrobial Agents and Chemotherapy
Enterobacterales species other than Klebsiella pneumoniae also contribute to OXA-48 carbapenemase endemicity. We studied the emergence of an OXA-48-producing Kluyvera species clone, which expresses the novel CTX-M-213 enzyme, colonizing patients in our hospital. Rectal swabs from patients admitted in four wards (March 2014 to March 2016; R-GNOSIS project) were seeded onto Chromo ID-ESBL) and Chrom-CARB/OXA-48 chromogenic agar plates. Carbapenemases and extended-spectrum β-lactamases (ESBLs) were characterized (PCR, sequencing, cloning, and site-directed mutagenesis), and antibiotic susceptibility was determined. Clonal relatedness was established (XbaI pulsed-field gel electrophoresis [XbaI-PFGE]), and plasmid content was studied (transformation, S1 nuclease digestion-PFGE, SB-hybridization, restriction fragment length polymorphism [RFLP] analysis [DraI and HpaI], and PCR [incompatibility group and repA, traU, and parA genes]). Whole-genome sequencing (WGS) (Illumina HiSeq-2500) and further bioinformatics analysis of plasmids (PLACNET and plasmidSPAdes) were performed. Patients' charts were reviewed. Six unrelated patients (median age, 75 years [range, 59 to 81 years]; 4/6 male patients) colonized with OXA-48-producing Kluyvera species isolates (>95% similarity of the PFGE pattern) were identified. Nosocomial acquisition was demonstrated. In two patients, OXA-48-producing Kluyvera species isolates coexisted with OXA-48-producing Raoultella ornithinolytica, K. pneumoniae, and Escherichia coli. The blaOXA-48 gene was located on an ∼60-kb IncL plasmid related to IncL/M-pOXA-48a and the novel blaCTX-M-213 gene in a conserved chromosomal region of Kluyvera species isolates. CTX-M-213, different from CTX-M-13 (K56E) but conferring a similar β-lactam resistance profile, was identified. Genomic analysis also revealed a 177-kb IncF plasmid (class I integron harboring sul1 and aadA2) and an 8-kb IncQ plasmid (IS4-blaFOX-8). We describe the first blaOXA-48 plasmid in Kluyvera spp. and the novel chromosomal CTX-M-213 enzyme and highlight further nosocomial dissemination of blaOXA-48 through clonal lineages or plasmids related to IncL/M-pOXA-48a. © 2018 American Society for Microbiology
Drivers of ecological success for Escherichia coli vary among human gut microbiome samples from different individuals
Boumasmoud, Mathilde; Leon-Sampedro, Ricardo; Beusch, Vera; et al. (2024)
bioRxiv
Gut microbial community composition varies from one person to another. Potentially, this means the ecological interactions experienced by individual strains or species also vary among microbiomes of different people. However, testing this directly in human microbiomes and identifying associated ecological drivers is challenging. Here, we use replicated anaerobic microcosms to quantify variability of population growth for a key commensal species among microbiome samples from different individuals, and to identify underlying intra- and interspecific interactions. In a reciprocal transplant experiment, both absolute and relative growth perfomance of different Escherichia coli strains varied among gut microbiome samples from different healthy individuals. This was partly explained by intraspecific competition: ecological success of individual E. coli strains was associated with displacement of resident conspecifics. However, the determinants of E. coli growth varied among samples from different individuals. In one microbiome sample with a distinctive taxonomic composition, culture acidification by resident microbes impaired growth of all E. coli strains. These results suggest inter-individual microbiome variation is a key driver of susceptibility to colonisation by incoming bacteria, impacting the relative success of different strains and thereby helping to explain the structure and diversity of human microbiomes.
Pervasive transmission of a carbapenem resistance plasmid in the gut microbiota of hospitalized patients
Leon-Sampedro, Ricardo; DelaFuente, Javier; Díaz-Agero, Cristina; et al. (2021)
Nature Microbiology
Infections caused by carbapenemase-producing enterobacteria (CPE) are a major concern in clinical settings worldwide. Two fundamentally different processes shape the epidemiology of CPE in hospitals: the dissemination of CPE clones from patient to patient (between-patient transfer), and the transfer of carbapenemase-encoding plasmids between enterobacteria in the gut microbiota of individual patients (within-patient transfer). The relative contribution of each process to the overall dissemination of carbapenem resistance in hospitals remains poorly understood. Here, we used mechanistic models combining epidemiological data from more than 9,000 patients with whole genome sequence information from 250 enterobacteria clones to characterize the dissemination routes of a pOXA-48-like carbapenemase-encoding plasmid in a hospital setting over a 2-yr period. Our results revealed frequent between-patient transmission of high-risk pOXA-48-carrying clones, mostly of Klebsiella pneumoniae and sporadically Escherichia coli. The results also identified pOXA-48 dissemination hotspots within the hospital, such as specific wards and individual rooms within wards. Using high-resolution plasmid sequence analysis, we uncovered the pervasive within-patient transfer of pOXA-48, suggesting that horizontal plasmid transfer occurs in the gut of virtually every colonized patient. The complex and multifaceted epidemiological scenario exposed by this study provides insights for the development of intervention strategies to control the in-hospital spread of CPE.

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Ricardo Leon-Sampedro

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