Anti-Virulence Strategy against the Multidrug-Resistant Bacterial Pathogen Pseudomonas aeruginosa: Pseudolysin (Elastase B) as a Potential Druggable Target

2019 ◽  
Vol 20 (5) ◽  
pp. 471-487 ◽  
Author(s):  
Anna Clara M. Galdino ◽  
Matheus P. de Oliveira ◽  
Teodorico C. Ramalho ◽  
Alexandre A. de Castro ◽  
Marta H. Branquinha ◽  
...  

Pseudomonas aeruginosa is a non-fermentative, gram-negative bacterium that is one of the most common pathogens responsible for hospital-acquired infections worldwide. The management of the infections caused by P. aeruginosa represents a huge challenge in the healthcare settings due to the increased emergence of resistant isolates, some of them resistant to all the currently available antimicrobials, which results in elevated morbimortality rates. Consequently, the development of new therapeutic strategies against multidrug-resistant P. aeruginosa is urgent and needful. P. aeruginosa is wellrecognized for its extreme genetic versatility and its ability to produce a lush variety of virulence factors. In this context, pseudolysin (or elastase B) outstands as a pivotal virulence attribute during the infectious process, playing multifunctional roles in different aspects of the pathogen-host interaction. This protein is a 33-kDa neutral zinc-dependent metallopeptidase that is the most abundant peptidase found in pseudomonal secretions, which contributes to the invasiveness of P. aeruginosa due to its ability to cleave several extracellular matrix proteins and to disrupt the basolateral intercellular junctions present in the host tissues. Moreover, pseudolysin makes P. aeruginosa able to overcome host defenses by the hydrolysis of many immunologically relevant molecules, including antibodies and complement components. The attenuation of this striking peptidase therefore emerges as an alternative and promising antivirulence strategy to combat antibiotic-refractory infections caused by P. aeruginosa. The anti-virulence approach aims to disarm the P. aeruginosa infective arsenal by inhibiting the expression/activity of bacterial virulence factors in order to reduce the invasiveness of P. aeruginosa, avoiding the emergence of resistance since the proliferation is not affected. This review summarizes the most relevant features of pseudolysin and highlights this enzyme as a promising target for the development of new anti-virulence compounds.

2021 ◽  
Author(s):  
Tran Hai Anh ◽  
Tran Huy Hoang ◽  
Vu Thi Ngoc Bich ◽  
Trinh Son Tung ◽  
Tran Dieu Linh ◽  
...  

Abstract Background: Multidrug-resistant bacteria including carbapenem resistant Pseudomonas aeruginosa are recognised as an important cause of hospital-acquired infections worldwide. To determine the molecular characterisation and antibiotic resistant genes associated with carbapenem-resistant P. aeruginosa. Methods: we conducted whole-genome sequencing and phylogenetic analysis of 72 carbapenem-resistant P. aeruginosa isolated from hospital-acquired infection patients from 2010 to 2015 in three major hospitals in Hanoi, Vietnam. Results: We identified three variants of IMP genes, among which IMP-15 gene was the most frequent (n= 34) in comparison to IMP-26 (n= 2) and IMP-51 (n=12). We observed two isolates with imipenem MIC >128mg/L that co-harboured IMP-15 and DIM-1 genes and seven isolates (imipenem MIC> 128mg/L) with KPC-1 gene from the same hospital. MLST data showed that sequence types (ST) of 72 isolates were classified into 18 STs and phylogenetic tree analysis divided these isolates into nine groups. Conclusion: Our results provide evidence that not only IMP-26, but other variants of IMPs like IMP-15 and IMP-51 genes and several STs (ST235, ST244, ST277, ST310, ST773 and ST3151) have been disseminated in health care settings in Vietnam. Also, we report the first finding in Vietnam that two isolates belonging to ST1240 and ST3340 harboured two important carbapenemase genes (IMP-15 and, DIM-1) and seven isolates belonging to ST3151 of P. aeruginosa carried the KPC-1 gene, which could be a potential cause of seriously restricted available treatment options in healthcare settings.


Antibiotics ◽  
2021 ◽  
Vol 10 (7) ◽  
pp. 877
Author(s):  
Ana Mafalda Pinto ◽  
Alberta Faustino ◽  
Lorenzo M. Pastrana ◽  
Manuel Bañobre-López ◽  
Sanna Sillankorva

Pseudomonas aeruginosa is responsible for nosocomial and chronic infections in healthcare settings. The major challenge in treating P. aeruginosa-related diseases is its remarkable capacity for antibiotic resistance development. Bacteriophage (phage) therapy is regarded as a possible alternative that has, for years, attracted attention for fighting multidrug-resistant infections. In this work, we characterized five phages showing different lytic spectrums towards clinical isolates. Two of these phages were isolated from the Russian Microgen Sextaphage formulation and belong to the Phikmvviruses, while three Pbunaviruses were isolated from sewage. Different phage formulations for the treatment of P. aeruginosa PAO1 resulted in diversified time–kill outcomes. The best result was obtained with a formulation with all phages, prompting a lower frequency of resistant variants and considerable alterations in cell motility, resulting in a loss of 73.7% in swimming motility and a 79% change in swarming motility. These alterations diminished the virulence of the phage-resisting phenotypes but promoted their growth since most became insensitive to a single or even all phages. However, not all combinations drove to enhanced cell killings due to the competition and loss of receptors. This study highlights that more caution is needed when developing cocktail formulations to maximize phage therapy efficacy. Selecting phages for formulations should consider the emergence of phage-resistant bacteria and whether the formulations are intended for short-term or extended antibacterial application.


2019 ◽  
Vol 6 (Supplement_2) ◽  
pp. S771-S772
Author(s):  
Sarah C J Jorgensen ◽  
Trang D Trinh ◽  
Evan J Zasowski ◽  
Sara Alosaimy ◽  
Abdalhamid M Lagnf ◽  
...  

Abstract Background Ceftazidime–avibactam (CZA) is a novel cephalosporin/β-lactamase inhibitor with activity against carbapenem-resistant Enterobacteriaceae (CRE) and multidrug-resistant (MDR) Pseudomonas aeruginosa (PA). Real-world experience with CZA for CRE infections is accumulating but data on its use for MDR PA infections remains limited. Methods Retrospective, multicenter cohort study describing the clinical characteristics and outcomes of patients treated with CZA (≥ 72 hours) for MDR PA infections between 2015 and 2018. Results Fifty-one patients were included. The median (IQR) age was 61 (43, 71) years. Most patients had MDR risk factors including recent hospitalization (74.5%), recent antimicrobial exposure (84.3%), and/or previous infection or colonization with an MDR pathogen (58.8%). The median Charlson Comorbidity score was 4 (2, 6) and the median APACHE II score was 20 (12, 29). Infections were predominantly (68.6%) hospital-acquired and 52.9% of patients were in the ICU at infection onset. The common sources were respiratory tract (60.8%), osteoarticular (11.8%) and skin and soft tissue (11.8%). Two patients had positive blood cultures. PA antibiotic susceptibilities were as follows: ceftazidime 52.6% (n = 51), CZA 92.0% (n = 25), ciprofloxacin 10% (n = 30), meropenem 19.6% (n = 46), piperacillin–tazobactam 30.4% (n = 4) and tobramycin 72.9% (n = 48). Most (60.8%) infections were polymicrobial including 15 (29.4) CRE co-infections. CZA was started 97 (50, 170) hours after culture collection and continued for 9 (7, 14) days. Only 8 patients (15.7%) received active antibiotic therapy before CZA. Combination CZA therapy was used 35.3%, most often an aminoglycoside (8/18, 44.4%). Clinical cure or improvement was achieved in 40 patients (78.4%), and 42 (82.4%) were discharged alive. Among patients with repeat cultures (n = 11), CZA resistance development was not detected. Three patients (5.9%) experienced infection recurrence within 30 days of completing therapy. Conclusion The use of CZA was associated with high rates of favorable outcomes in complex patients with MDR PA infections. Future studies evaluating long-term outcomes and comparative studies are needed to more precisely define the role of CZA for MDR PA infections. Disclosures All authors: No reported disclosures.


2019 ◽  
Vol 10 (9) ◽  
pp. 5759-5767
Author(s):  
Wan-Ting Lee ◽  
Boon-Khai Tan ◽  
Su-Anne Eng ◽  
Gan Chee Yuen ◽  
Kit Lam Chan ◽  
...  

A strategy to circumvent the problem of multidrug resistant pathogens is the discovery of anti-infectives targeting bacterial virulence or host immunity.


Molecules ◽  
2020 ◽  
Vol 25 (2) ◽  
pp. 415 ◽  
Author(s):  
Elise Pierson ◽  
Marie Haufroid ◽  
Tannu Priya Gosain ◽  
Pankaj Chopra ◽  
Ramandeep Singh ◽  
...  

Mycobacterium tuberculosis is still the deadliest bacterial pathogen worldwide and the increasing number of multidrug-resistant tuberculosis cases further complicates this global health issue. M. tuberculosis phosphoserine phosphatase SerB2 is a promising target for drug design. Besides being a key essential metabolic enzyme of the pathogen’s serine pathway, it appears to be involved in immune evasion mechanisms. In this work, a malachite green-based phosphatase assay has been used to screen 122 compounds from an internal chemolibrary. Trisubstituted harmine derivatives were found among the best hits that inhibited SerB2 activity. Synthesis of an original compound helped to discuss a brief structure activity relationship evaluation. Kinetics experiments showed that the most potent derivatives inhibit the phosphatase in a parabolic competitive fashion with apparent inhibition constants ( K i ) values in the micromolar range. Their interaction modes with the enzyme were investigated through induced fit docking experiments, leading to results consistent with the experimental data. Cellular assays showed that the selected compounds also inhibited M. tuberculosis growth in vitro. Those promising results may provide a basis for the development of new antimycobacterial agents targeting SerB2.


2020 ◽  
Vol 2020 ◽  
pp. 1-11
Author(s):  
Mustafa Elhag ◽  
Ruaa Mohamed Alaagib ◽  
Nagla Mohamed Ahmed ◽  
Mustafa Abubaker ◽  
Esraa Musa Haroun ◽  
...  

Pseudomonas aeruginosa is a common pathogen that is responsible for serious hospital-acquired infections, ventilator-associated pneumonia, and various sepsis syndromes. Also, it is a multidrug-resistant pathogen recognized for its ubiquity and its intrinsically advanced antibiotic-resistant mechanisms. It usually affects immunocompromised individuals but can also infect immunocompetent individuals. There is no vaccine against it available till now. This study predicts an effective epitope-based vaccine against fructose bisphosphate aldolase (FBA) of Pseudomonas aeruginosa using immunoinformatics tools. The protein sequences were obtained from NCBI, and prediction tests were undertaken to analyze possible epitopes for B and T cells. Three B cell epitopes passed the antigenicity, accessibility, and hydrophilicity tests. Six MHC I epitopes were found to be promising, while four MHC II epitopes were found promising from the result set. Nineteen epitopes were shared between MHC I and II results. For the population coverage, the epitopes covered 95.62% worldwide excluding certain MHC II alleles. We recommend in vivo and in vitro studies to prove its effectiveness.


Antibiotics ◽  
2020 ◽  
Vol 9 (12) ◽  
pp. 885
Author(s):  
Soraya Herrera-Espejo ◽  
Tania Cebrero-Cangueiro ◽  
Gema Labrador-Herrera ◽  
Jerónimo Pachón ◽  
María Eugenia Pachón-Ibáñez ◽  
...  

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.


Antibiotics ◽  
2019 ◽  
Vol 8 (3) ◽  
pp. 148 ◽  
Author(s):  
Cuong Hoang Quoc ◽  
Thao Nguyen Thi Phuong ◽  
Hai Nguyen Duc ◽  
Trung Tran Le ◽  
Hang Tran Thi Thu ◽  
...  

Background: Acinetobacter baumannii (Ab) is an opportunistic bacterial pathogen found in hospital-acquired infections including nosocomial pneumonia, especially multidrug-resistant Ab. This study aims to survey the drug resistance profiles of Ab isolated from patients in Thong Nhat Dong Nai General Hospital and assess the relationship between genotypes and antibiotic resistance; Methods: Ninety-seven Ab strains isolated from 340 lower respiratory tract specimens among pneumonia patients were used to screen the most common local carbapenemase genes. Antimicrobial susceptibility testing results and demographic data were collected and minimum inhibitory concentrations (MIC) of colistin were also determined; Results: Over 80% and 90% of Ab strains were determined as carbapenem-resistant and multidrug-resistant (MDR), respectively. Most of the strains carried carbapenemase genes, including blaOXA-51, blaOXA-23-like, blaOXA-58-like, and blaNDM-1, with proportions of 97 (100%), 76 (78.4%), 10 (10.3%), 6 (6.2%), respectively. Amongst these genes, blaOXA-23-like was the only gene which significantly influenced the resistance (p < 0.0001); and Conclusions: The severity of Ab antibiotic resistance is urgent and specifically related to carbapenemase encoding genes. Therefore, screening of MDR Ab and carbapenemase for better treatment options is necessary.


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