In vitro activity of piperazine derivates against multidrug-resistance bacteria

Motivation: The increasing prevalence of multidrug-resistance represent a serious challenge for clinical management and public health. Multidrug-resistant (MDR) bacteria is a common cause of infections, especially in inmunocompromised patient. Nowadays, colistin has re-emerged as one of the last therapeutic option against these kinds of infections, but colistin resistant strains have been reported, leaving no alternative of treatment. The aim of this work is to study in vitro the activity of piperazine derivates against MDR and colistin resistant bacteria. Methods: Clinical and standard strains: MDR: Acinetobacter baumannii (Ab; n=1), Klebsiella pneumoniae carbapenemases producing (n=4), Pseudomonas aeruginosa (Pa; n=2), Escherichia coli ATCC 25922 (n=1), colistin resistant A. baumannii (n=13). Piperazine derivatives: four different families were tested: 1, 2, 3, and 4. The derivivates were synthesized in the Pharmacy Faculty of Seville. A) Inhibition screening: all strains at a concentration of 5x105 CFU/mL were tested at 50 µM of each derivative. B) Minimal Inhibitory Concentration (MIC): were calculated for the derivates that inhibit the bacterial growth. C) Time-kill curves: were performed for six derivates against two colistin resistant A. baumannii clinical strains.  Results: A) Inhibition was observed only in colistin resistant A. baumannii clinical strains. B) Family 1, inhibited the growth of 46 % (6/13) of the strains. Family 2, inhibited the growth of 30% (4/13) of the strains. Family 3, inhibited the growth of 30% (4/13) of the strains. Family 4, inhibited the growth of 38% (5/13) of the strains. C) Family 1: MIC range was 50-3.12 µM. Family 2: MIC range was 50-6.25 µM. Family 3: MIC range was 50-1.56 µM. Family 4: MIC range was 50-3.12 µM. D) One piperazine derivates presented bactericidal activity at 24 hours against one of the tested strains.  Conclusions: Piperazine derivatives showed in vitro activity against colistin resistant A. baumannii clinical strains. Further studies, in vitro and in vivo need to be performed in order to confirm the activity of the piperazine derivates against infections due to these kinds of infections

Perspectives for clinical use of engineered human host defense antimicrobial peptides.

Infectious diseases caused by bacteria, viruses or fungi are among the leading causes of death worldwide. The emergence of drug-resistance mechanisms, especially among bacteria, threatens the efficacy of all current antimicrobial agents, some of them already ineffective. As a result, there is an urgent need for new antimicrobial drugs. Host defense antimicrobial peptides (HDPs) are natural occurring and well-conserved peptides of innate immunity, broadly active against Gram-negative and Gram-positive bacteria, viruses and fungi. They also are able to exert immunomodulatory and adjuvant functions by acting as chemotactic for immune cells, and inducing cytokines and chemokines secretion. Moreover, they show low propensity to elicit microbial adaptation, probably because of their non-specific mechanism of action, and are able to neutralize exotoxins and endotoxins. HDPs have the potential to be a great source of novel antimicrobial agents. The goal of this review is to provide an overview of the advances made in the development of human defensins as well as the cathelicidin LL-37 and their derivatives as antimicrobial agents against bacteria, viruses and fungi for clinical use

In vitro activity of pentamidine alone and in combination with antibiotics against multidrug-resistant clinical Pseudomonas aeruginosa strains

Multidrug-resistant (MDR) Pseudomonas aeruginosa is a public health problem causing both community and hospital-acquired infections, and thus the development of new therapies for these infections is critical. The objective of this study was to analyze in vitro the activity of pentamidine as adjuvant in combinations to antibiotics against seven clinical P. aeruginosa strains. The Minimum Inhibitory Concentration (MIC) was determined following standard protocols, and the results were interpreted according to the European Committee on Antimicrobial Susceptibility Testing (EUCAST) breakpoints; however, the gentamicin activity was interpreted according to the Clinical and Laboratory Standards Institute (CLSI) recommendations. The bactericidal in vitro activity was studied at 1×MIC concentrations by time–kill curves, and also performed in three selected strains at 1/2×MIC of pentamidine. All studies were performed in triplicate. The pentamidine MIC range was 400–1600 µg/mL. Four of the strains were MDR, and the other three were resistant to two antibiotic families. The combinations of pentamidine at 1×MIC showed synergistic activity against all the tested strains, except for pentamidine plus colistin. Pentamidine plus imipenem and meropenem were the combinations that showed synergistic activity against the most strains. At 1/2×MIC, pentamidine plus antibiotics were synergistic with all three analyzed strains. In summary, pentamidine in combination with antibiotics showed in vitro synergy against multidrug-resistant P. aeruginosa clinical strains, which suggests its possible use as adjuvant to antibiotics for the therapy of infections from MDR P. aeruginosa.Instituto de Salud Carlos III Proyectos de Investigación en Salud PI18-01842Subdirección General de Redes y Centros de Investigación Cooperativa, Ministerio de Economía, Industria y Competitividad, Red Española de Investigación en Enfermedades Infecciosas REIPI RD16 / 0016/0009Fondo Regional de Desarrollo Europeo Una forma de lograr Europa, Operativa programa Crecimiento inteligente 2014-2020. T.CUniversidad de Sevilla. Servicio Andaluz de Salud, Junta de Andalucía C1-0038-2019Ministerio de Ciencia, Innovación y Universidades, Instituto de Salud Carlos III, cofinanciado por la Unión Fondo Regional de Desarrollo RD16 / 0016/0009Ministerio de Ciencia, Innovación y Universidades, Instituto de Salud Carlos III, cofinanciado por European Development Regional Fund (A Way to Achieve Europe) y por la Red Española de Investigación en Enfermedades Infecciosas JR17 / 0002

In silico discovery of Acinetobacter baumannii genes involved in microaerobiosis resistance

Motivation: the infectious ability of Acinetobacter baumannii combined with its antibiotic resistant profile turn this bacteria into a objective with global priority, being currently highlighted by the World Health Organization as one of the most relevant resistant bacteria. Thanks to the development of Next-Generation Sequencing Methods, we can apply bioinformatics tools to analyse data that give us information about the behaviour of the bacteria under different conditions, which gives us the opportunity to discover new pharmacological targets that allow us to fight against infections by A. baumannii.Methods: We use data from RNA-Seq technique, obtained from A. baumannii ATCC 17978 growth in two different conditions: normoxia (21% O2) and microaerobiosis (0.1-0.3% O2). The first one is the regular situation, while the second one is the condition that the bacteria suffer when an infection occurs, especially across an injury, during the inflammatory phase. The results of this transcriptomic experiment were subjected to a bioinformatic workflow, starting with the quality analysis and trimming process, followed by the alignment of the reads and their quantification, until the differential expression analysis, whose results were filtered according to fold change value (R2>=1) and p-value (padj<0.05). Additionally, we want to improve the current annotation from A. baumannii ATCC 17978 genome. For that purpose, three sources of candidates were combined: GenBank available information, Prokka predictions and AnaBlast predictions. With this annotation, we can associate possible paths and processes in which the differential expression genes could be implicated, by a functional enrichment analysis using GO terms and KEGG, and the packages from R programming languages, such as Bioconductor and Clusterprofiler.Results: Resultados obtenidos. No tienen porqué aparecer todos los apartados (se puede prescindir de alguno de ellos, o todos). No más de 2500 caracteres el total del resumen. Incluir aparte (en el apartado de debajo) 1-3 referencias bibliográficas.Conclusions: The differentially expressed genes are enriched in X and Y, and these pathways have later been reviewed and completed by manual annotation using specific proteins databases. This could give us key information about the behaviour of the bacteria when it is found in hypoxia during the infection, and we could even find some factors involved in its virulence

Statistical analysis plan. Study protocol for a randomized clinical trial to assess 7 versus 14-days of treatment for Pseudomonas aeruginosa bloodstream infections (SHORTEN-2 trial)

Efficacy and safety of 7 versus 14 days of antibiotic treatment for Pseudomonas aeruginosa bacteraemia: a multicentre, randomized clinical trial (SHORTEN-2) with a DOOR/RADAR analysis.Peer reviewe

Full-length study protocol (Spanish). Study protocol for a randomized clinical trial to assess 7 versus 14-days of treatment for Pseudomonas aeruginosa bloodstream infections (SHORTEN-2 trial)

Eficacia y seguridad de 7 versus 14 días de tratamiento antibiótico para la bacteriemia producida por Pseudomonas aeruginosa: un ensayo clínico multicéntrico, aleatorizado (SHORTEN-2) con un análisis DOOR/RADAR.Peer reviewe

Results of the survey among participating centers regarding diagnostic and clinical routines for the management of BSI-PA

S4 File. Results of the survey among participating centers regarding diagnostic and clinical routines for the management of BSI-PAPeer reviewe