Resistance against two lytic phage variants attenuates virulence and antibiotic resistance in Pseudomonas aeruginosa

Reviving the past for a healthier future: ancient molecules and remedies as a solution to the antibiotic crisis

Options to combat bacterial infections are becoming scarce. We require innovative approaches to enhance the discovery of effective antimicrobials capable of combating bacteria resistant to multiple or all antibiotics. These methods should either directly eliminate resistant bacteria or indirectly influence their viability by inhibiting their virulence or reducing their resistance to antibiotics. One interesting approach is to analyze ancient remedies used to treat bacterial infections, formulate them, and test them against modern microbes. This field has recently been named "ancientbiotics." This approach allows us to leverage centuries of empirical knowledge accumulated, from traditional medicines across various ancient cultures worldwide. The strategy has already yielded promising formulations to combat the ESKAPE group of nosocomial pathogens. Additionally, molecular de-extinction, which involves genome analysis of extinct species to search for useful antimicrobials, such as peptides, offers another avenue. In this review, we compile the antimicrobial effects of ancient remedies and de-extinct molecules known to modern science and discuss possible new strategies to further harness the potential of past remedies and molecules to fight the rise of superbugs.

Study of the probability of resistance to phage infection in a collection of clinical isolates of Pseudomonas aeruginosa in relation to the presence of Pf phages

Pseudomonas aeruginosa is a bacterial pathogen that is a major cause of lung infections in cystic fibrosis (CF) and other patients. Isolates of P. aeruginosa from CF patients commonly carry filamentous phages (Pf phages), which constitute a family of temperate phages known to be related to biofilm production and antibiotic sequestration. In this study, we identified 12 new Pf phage genomes in a collection of clinical isolates of P. aeruginosa from CF patients. Study of the anti-phage defense systems in the bacterial isolates revealed the presence of 89 such systems, of which eight were encoded in the Pf phage genomes. Finally, although a weak relation between resistance to phage infection and the number of anti-phage defense systems was detected, it was observed that the phage resistance was related to the presence of Pf phages and the anti-phage defense systems encoded in these phages.IMPORTANCEBacteria harbor a wide range of defense mechanisms to avoid phage infections that hamper the application of phage therapy because they can lead to the rapid acquisition of phage resistance. In this study, eight anti-phage defense systems were found in the genome of 12 Pf phages that were presents in 56% of the CF isolates of P. aeruginosa. The high prevalence of these phages underlines the importance of our findings about newly discovered filamentous phages and the role of these phages in resistance to phage infections. Thus, the knowledge of the anti-defense system in the Pf phage genomes could be useful in assessing the possible application of phage therapy to treat an infectious disease.

Phage therapeutic delivery methods and clinical trials for combating clinically relevant pathogens

The ongoing global health crisis caused by multidrug-resistant (MDR) bacteria necessitates quick interventions to introduce new management strategies for MDR-associated infections and antimicrobial agents' resistance. Phage therapy emerges as an antibiotic substitute for its high specificity, efficacy, and safety profiles in treating MDR-associated infections. Various in vitro and in vivo studies denoted their eminent bactericidal and anti-biofilm potential. This review addresses the latest developments in phage therapy regarding their attack strategies, formulations, and administration routes. It additionally discusses and elaborates on the status of phage therapy undergoing clinical trials, and the challenges encountered in their usage, and explores prospects in phage therapy research and application.

Current developments and prospects of the antibiotic delivery systems

Antibiotics have remained the cornerstone for the treatment of bacterial infections ever since their discovery in the twentieth century. The uproar over antibiotic resistance among bacteria arising from genome plasticity and biofilm development has rendered current antibiotic therapies ineffective, urging the development of innovative therapeutic approaches. The development of antibiotic resistance among bacteria has further heightened the clinical failure of antibiotic therapy, which is often linked to its low bioavailability, side effects, and poor penetration and accumulation at the site of infection. In this review, we highlight the potential use of siderophores, antibodies, cell-penetrating peptides, antimicrobial peptides, bacteriophages, and nanoparticles to smuggle antibiotics across impermeable biological membranes to achieve therapeutically relevant concentrations of antibiotics and combat antimicrobial resistance (AMR). We will discuss the general mechanisms via which each delivery system functions and how it can be tailored to deliver antibiotics against the paradigm of mechanisms underlying antibiotic resistance.