Chapters authored
The Role of Pseudomonas aeruginosa RNA Methyltransferases in Antibiotic Resistance
Methyltransferases play a fundamental role in aminoglycoside resistance of Gram-negative bacteria, and some of its mechanisms were described in the past years, especially in Escherichia coli; however, it remains unsolved for other resistant bacteria such as Pseudomonas aeruginosa. Despite hurdles to determine resistance acquisition, high-throughput approaches (genomics, transcriptomics, and proteomics) have allowed data mining and analysis in a systemic way. Likewise, bioinformatics modelling of homologous genes or proteins has permitted to elucidate the emerging resistance in this pathogen. P. aeruginosa is a bacterial resistance treat since practically all known resistance mechanisms can be described using this model, particularly RNA methyltransferases. The RNA methyltransferases perform methylation or demethylation of ribosomal RNA to allow or restrict the antibiotic resistance development. The Kgm and Kam methyltransferases families are found in P. aeruginosa and confer resistance to several aminoglycosides. Loss of native methylations may also confer a resistant phenotype. The P. aeruginosa RsmG has high structural homology with Thermus aquaticus protein. Today, molecular data will promote a new paradigm on antibiotic therapy for treatment against P. aeruginosa. This chapter provides an overview of what role P. aeruginosa’s methyltransferases play in antibiotic resistance, induced by methylation or demethylation in the ribosome.
Part of the book: Pseudomonas Aeruginosa
Searching for the Resistance Interactome of Pseudomonas aeruginosa
Pseudomonas aeruginosa is one of the most important emerging Gram-negative pathogenic bacilli worldwide. The development of antibiotic resistance and its ability to adapt to multiple environmental conditions keep triggering alarms in global hospitals since the invasion of different types of tissues. This facultative anaerobe can adapt easily to aerobic or anaerobic conditions. It invades tissues, such as the lung, gastrointestinal tract, skin, renal system, and urinary tract, to the extreme of causing a variety of punctate gangrene. The considerable size of its genome (core and accessory genome) shows that this bacterium carries a huge battery of genes that allow it to develop resistance to various antibiotics, emerging as an MDR bacterium. The most studied mechanisms for resistance development have been quorum sensing and biofilm formation, among others. The research of resistance genes has been a long and time-consuming task. Genes such as CARB-3, CARB-4, PSE-1 (CARB-2), PSE-4 (CARB-1), OXA-18, OXA-2, OXA-21, OXA-10 (PSE-2), GyrA, GyrB, OprM, OprJ, OprN, MexB, MODx, MexF, and MexY, are among the best-characterized genes in P. aeruginosa. Another group of not-so-conventional genes is the methyltransferases, which have been negligible studied in P. aeruginosa. In this article, we propose to give a state of the art of the most important resistance genes of P. aeruginosa and their relationship with the interactome-resistome.
Part of the book: Pseudomonas aeruginosa
The Pangenome of Pseudomonas aeruginosa
This review summarizes the most important reports about Pseudomonas aeruginosa pangenome. Pan-genomics has tackled some fundamental concerns in pathogenic bacteria. PATRIC and other databases, store more than 9000 P. aeruginosa genomes. This data mining is an opportunity to develop discoveries related to antibiotic resistance, virulence, pathogenicity, fitness, and evolution, among others. Observing the different pangenomes of P. aeruginosa, it is concluded that this species has an open pangenome, and its accessory genome is larger than the central genome. HGT is one important source for P. aeruginosa genome. In recent years various authors developed P. aeruginosa pangenomes, from works with five genomes to more than 1300 genomes. This last work analyzed 54,272 genes, and they found a short and tiny core genome (only 665 genes). Other research with lesser strains or genomes identified a core genome bigger, almost 20% of the pangenome. Nevertheless, the total work proves that the accessory plus unique genome is larger than the core genome in P. aeruginosa.
Part of the book: Pseudomonas aeruginosa