Synthetic biology in Mycoplasma pneumoniae

M. pneumoniae is one of the smallest self-replicating organisms. Many organism wide studies have been performed on M. pneumoniae and provide a wealth of information on the bacteria. However, the genetic tools to manipulate and engineer this microorganism are currently insufficient. Therefore one focus of this project is to extend the genetic toolbox for M. pneumoniae. In parallel, we developed first a proof of concepts study for the use of M. pneumoniae as therapeutical vector. For this purpose the secretome of M. pneumoniae has been investigated to define all secretion signals in this bacterium. This knowledge was used to modify M. pneumoniae to secrete three proteins with therapeutical applications. Further we could show for two of the proteins that they are active after secretion and therefore that M. pneumoniae can be used to engineer therapeutic vectors for treating lungs diseases.M. pneumoniae es uno de los microrganismos auto-replicativos más pequeños descritos hasta el momento. En nuestro grupo se ha empleado como modelo en Biología de Sistemas y se ha caracterizado a diferentes niveles (genoma, transcriptoma, proteoma...etc). Sin embargo, las herramientas genéticas para manipular y emplear este microorganismo como modelo en Bilogía Sintética, son insuficientes. Por lo tanto, uno de los objetivos de este proyecto es ampliar el repertorio de herramientas moleculares de M. pneumoniae. En paralelo, hemos desarrollado por primera vez una “prueba de concepto” para el uso de M. pneumoniae con finalidades terapéuticas. Con este propósito, primero hemos determinado el secretoma de M. pneumoniae que ha permitido identificar todas las señales de secreción de esta bacteria. Posteriormente, se ha aplicado este conocimiento para obtener cepas de M. pneumoniae capaces de secretar tres proteínas con aplicaciones terapéuticas. Hemos demostrado que dos de las tres proteínas son activas tras la secreción, abriendo nuevas perspectivas en el uso de M. pneumoniae para el tratamiento de enfermedades pulmonares

Synthetic biology in Mycoplasma pneumoniae

M. pneumoniae is one of the smallest self-replicating organisms. Many organism wide studies have been performed on M. pneumoniae and provide a wealth of information on the bacteria. However, the genetic tools to manipulate and engineer this microorganism are currently insufficient. Therefore one focus of this project is to extend the genetic toolbox for M. pneumoniae. In parallel, we developed first a proof of concepts study for the use of M. pneumoniae as therapeutical vector. For this purpose the secretome of M. pneumoniae has been investigated to define all secretion signals in this bacterium. This knowledge was used to modify M. pneumoniae to secrete three proteins with therapeutical applications. Further we could show for two of the proteins that they are active after secretion and therefore that M. pneumoniae can be used to engineer therapeutic vectors for treating lungs diseases.M. pneumoniae es uno de los microrganismos auto-replicativos más pequeños descritos hasta el momento. En nuestro grupo se ha empleado como modelo en Biología de Sistemas y se ha caracterizado a diferentes niveles (genoma, transcriptoma, proteoma...etc). Sin embargo, las herramientas genéticas para manipular y emplear este microorganismo como modelo en Bilogía Sintética, son insuficientes. Por lo tanto, uno de los objetivos de este proyecto es ampliar el repertorio de herramientas moleculares de M. pneumoniae. En paralelo, hemos desarrollado por primera vez una “prueba de concepto” para el uso de M. pneumoniae con finalidades terapéuticas. Con este propósito, primero hemos determinado el secretoma de M. pneumoniae que ha permitido identificar todas las señales de secreción de esta bacteria. Posteriormente, se ha aplicado este conocimiento para obtener cepas de M. pneumoniae capaces de secretar tres proteínas con aplicaciones terapéuticas. Hemos demostrado que dos de las tres proteínas son activas tras la secreción, abriendo nuevas perspectivas en el uso de M. pneumoniae para el tratamiento de enfermedades pulmonares

From dysbiosis to healthy skin: major contributions of Cutibacterium acnes to skin homeostasis

Cutibacterium acnes is the most abundant bacterium living in human, healthy and sebum-rich skin sites, such as the face and the back. This bacterium is adapted to this specific environment and therefore could have a major role in local skin homeostasis. To assess the role of this bacterium in healthy skin, this review focused on (i) the abundance of C. acnes in the skin microbiome of healthy skin and skin disorders, (ii) its major contributions to human skin health, and (iii) skin commensals used as probiotics to alleviate skin disorders. The loss of C. acnes relative abundance and/or clonal diversity is frequently associated with skin disorders such as acne, atopic dermatitis, rosacea, and psoriasis. C. acnes, and the diversity of its clonal population, contributes actively to the normal biophysiological skin functions through, for example, lipid modulation, niche competition and oxidative stress mitigation. Compared to gut probiotics, limited dermatological studies have investigated skin probiotics with skin commensal strains, highlighting their unexplored potential

Safety and efficacy of topically applied selected cutibacterium acnes strains over five weeks in patients with acne vulgaris: an open-label, pilot study

Imbalance in skin microflora, particularly related to certain Cutibacterium acnes strains, may trigger acne. Application of non-acne-causing strains to the skin may modulate the skin microbiome and thereby lead to a reduction in acne. This pilot study evaluates the safety and efficacy of microbiome modulation on acne-prone skin. The study had 2 phases: active induction (5% benzoyl peroxide gel, 7 days) and interventional C. acnes strains treatment (5 weeks). Patients were randomized to either topical skin formulations PT1 (2 strains of C. acnes Single Locus Sequence Typing [SLST] type C3 and K8, 50% each) or PT2 (4 strains of C. acnes SLST type C3 [55%], K8 [5%], A5 [30%] and F4 [10%]). Safety and efficacy was evaluated in 14 patients (PT1=8/14, PT2=6/14). Skin microbiome composition shifted towards study formulations. No untoward adverse events, visible irritation, or significant flare-up were observed. Non-inflamed lesions and skin pH were reduced. Comedone counts improved clinically with no deterioration in inflammatory lesions

Safety and efficacy of topically applied selected cutibacterium acnes strains over five weeks in patients with acne vulgaris: an open-label, pilot study

Imbalance in skin microflora, particularly related to certain Cutibacterium acnes strains, may trigger acne. Application of non-acne-causing strains to the skin may modulate the skin microbiome and thereby lead to a reduction in acne. This pilot study evaluates the safety and efficacy of microbiome modulation on acne-prone skin. The study had 2 phases: active induction (5% benzoyl peroxide gel, 7 days) and interventional C. acnes strains treatment (5 weeks). Patients were randomized to either topical skin formulations PT1 (2 strains of C. acnes Single Locus Sequence Typing [SLST] type C3 and K8, 50% each) or PT2 (4 strains of C. acnes SLST type C3 [55%], K8 [5%], A5 [30%] and F4 [10%]). Safety and efficacy was evaluated in 14 patients (PT1=8/14, PT2=6/14). Skin microbiome composition shifted towards study formulations. No untoward adverse events, visible irritation, or significant flare-up were observed. Non-inflamed lesions and skin pH were reduced. Comedone counts improved clinically with no deterioration in inflammatory lesions

Engineering selectivity of Cutibacterium acnes phages by epigenetic imprinting

Cutibacterium acnes (C. acnes) is a gram-positive bacterium and a member of the human skin microbiome. Despite being the most abundant skin commensal, certain members have been associated with common inflammatory disorders such as acne vulgaris. The availability of the complete genome sequences from various C. acnes clades have enabled the identification of putative methyltransferases, some of them potentially belonging to restriction-modification (R-M) systems which protect the host of invading DNA. However, little is known on whether these systems are functional in the different C. acnes strains. To investigate the activity of these putative R-M and their relevance in host protective mechanisms, we analyzed the methylome of six representative C. acnes strains by Oxford Nanopore Technologies (ONT) sequencing. We detected the presence of a 6-methyladenine modification at a defined DNA consensus sequence in strain KPA171202 and recombinant expression of this R-M system confirmed its methylation activity. Additionally, a R-M knockout mutant verified the loss of methylation properties of the strain. We studied the potential of one C. acnes bacteriophage (PAD20) in killing various C. acnes strains and linked an increase in its specificity to phage DNA methylation acquired upon infection of a methylation competent strain. We demonstrate a therapeutic application of this mechanism where phages propagated in R-M deficient strains selectively kill R-M deficient acne-prone clades while probiotic ones remain resistant to phage infection

Skin microbiome modulation induced by probiotic solutions

Background: The skin is colonized by a large number of microorganisms, most of which are beneficial or harmless. However, disease states of skin have specific microbiome compositions that are different from those of healthy skin. Gut microbiome modulation through fecal transplant has been proven as a valid therapeutic strategy in diseases such as Clostridium difficile infections. Therefore, techniques to modulate the skin microbiome composition may become an interesting therapeutic option in diseases affecting the skin such as psoriasis or acne vulgaris. Methods: Here, we have used mixtures of different skin microbiome components to alter the composition of recipient skin microbiomes. Results: We show that after sequential applications of a donor microbiome, the recipient microbiome becomes more similar to the donor. After intervention, an initial week-long phase is characterized by the dominance of donor strains. The level of engraftment depends on the composition of the recipient and donor microbiomes, and the applied bacterial load. We observed higher engraftment using a multi-strain donor solution with recipient skin rich in Cutibacterium acnes subtype H1 and Leifsonia. Conclusions: We have demonstrated the use of living bacteria to modulate skin microbiome composition

Skin microbiome modulation induced by probiotic solutions

Background: The skin is colonized by a large number of microorganisms, most of which are beneficial or harmless. However, disease states of skin have specific microbiome compositions that are different from those of healthy skin. Gut microbiome modulation through fecal transplant has been proven as a valid therapeutic strategy in diseases such as Clostridium difficile infections. Therefore, techniques to modulate the skin microbiome composition may become an interesting therapeutic option in diseases affecting the skin such as psoriasis or acne vulgaris. Methods: Here, we have used mixtures of different skin microbiome components to alter the composition of recipient skin microbiomes. Results: We show that after sequential applications of a donor microbiome, the recipient microbiome becomes more similar to the donor. After intervention, an initial week-long phase is characterized by the dominance of donor strains. The level of engraftment depends on the composition of the recipient and donor microbiomes, and the applied bacterial load. We observed higher engraftment using a multi-strain donor solution with recipient skin rich in Cutibacterium acnes subtype H1 and Leifsonia. Conclusions: We have demonstrated the use of living bacteria to modulate skin microbiome composition

Engineering a genome-reduced bacterium to eliminate Staphylococcus aureus biofilms in vivo

Bacteria present a promising delivery system for treating human diseases. Here, we engineered the genome-reduced human lung pathogen Mycoplasma pneumoniae as a live biotherapeutic to treat biofilm-associated bacterial infections. This strain has a unique genetic code, which hinders gene transfer to most other bacterial genera, and it lacks a cell wall, which allows it to express proteins that target peptidoglycans of pathogenic bacteria. We first determined that removal of the pathogenic factors fully attenuated the chassis strain in vivo. We then designed synthetic promoters and identified an endogenous peptide signal sequence that, when fused to heterologous proteins, promotes efficient secretion. Based on this, we equipped the chassis strain with a genetic platform designed to secrete antibiofilm and bactericidal enzymes, resulting in a strain capable of dissolving Staphylococcus aureus biofilms preformed on catheters in vitro, ex vivo, and in vivo. To our knowledge, this is the first engineered genome-reduced bacterium that can fight against clinically relevant biofilm-associated bacterial infections.This work has been supported by the European Research Council (ERC) under the European Union’s Horizon 2020 research and innovation program, under grant agreement 670216 (MYCOCHASSIS). We also acknowledge the support of the Spanish Ministry of Economy, Industry and Competitiveness (MEIC) to the EMBL partnership, the Centro de Excelencia Severo Ochoa, the CERCA Program from the Generalitat de Catalunya, the European Union’s Horizon 2020 research and innovation program under grant agreement 634942 (MycoSynVac), and the La Caixa Fundation grant (Livetherapeutics HR18-00058). M.L.-S. acknowledges the support from FEDER project from Instituto Carlos III (ISCIII, Acción Estratégica en Salud 2016) (reference CP16/00094). We also acknowledge the staff of CRG/UPF Proteomics Unit, which is part of the Spanish Infrastructure for Omics Technologies (ICTS OmicsTech) unit is a member of the ProteoRed PRB3 consortium, which is supported by grant PT17/0019 of the PE I + D+i 2013-2016 from the Instituto de Salud Carlos III (ISCIII) and ERD