In vitro and in vivo antibacterial activity of environmental bacteriophages against Pseudomonas aeruginosa strains from cystic fibrosis patients

Abstract

The goal of the study was to determine the relationship between in vitro/in vivo efficacy of environmental Pseudomonas phages and certain phenotypical properties of Pseudomonas aeruginosa (PA) strains. We studied the diversity between particular isolates and determined phage sensitivity in vitro and in vivo in the Galleria mellonella insect model. Twenty-eight lytic bacteriophages specific for PA were tested against 121 CF PA isolates including 29 mucoid PA strains. Most strains from cystic fibrosis (CF) patients were lysed by at least three phages (93.6 %), but completely insensitive strains were also present (6.4 %). Two phages PA5oct and KT28 exhibited high rates of lytic potency on 55–68 % of PA strains (72–86 % of mucoid isolates). We further explored phage activity against six PA strains (CF and non-CF) in vitro, comparing clonal differences in phage susceptibility with bacterial properties such as the ability to form biofilms, mucosity, twitching motility, and biochemical profiles. We observed the relationship between variation in phage susceptibility and Fourier transform infrared spectroscopy (FTIR) analysis in the spectra window of carbohydrates. The protective efficacy of two selected phages against PA PAO1 and 0038 infection was confirmed in vivo in G. mellonella larvae. Generally, the wax moth model results confirmed the data from in vitro assays, but in massive infection of CF isolates, the application of lytic phages probably led to the release of toxic compound causing an increase in larvae mortality. We assumed that apart of in vitro phage activity testing, a simple and convenient wax moth larvae model should be applied for the evaluation of in vivo effectiveness of particular phage preparations.

Production of highly stable spray dried phage formulations for treatment of Pseudomonas aeruginosa lung infection

“…Potential advantages of phage therapy over conventional antibiotic treatment are due to the facts that phages are (i) naturally occurring antibacterials with low inherent toxicity, (ii) self-amplifying agents, and (iii) highly specific limiting unnecessary damage to non-targeted bacteria [7, 8]. The activity of phages against MDR bacteria has been shown in in vitro studies [9, 10] as well as their efficacy in animals [10–12] and humans [13–15]. A recent study used intranasal administration of phages to reduce the infective burden and inflammation in a P. aeruginosa lung infection model in mice [11].…”

Characterization of the first double-stranded RNA bacteriophage infecting Pseudomonas aeruginosa

“…Given that P. aeruginosa is becoming resistant to most antibiotics, a common infection may be fatal. Therefore, the feasibility of treating bacterial infections with bacteriophages has been extensively studied2728293031. Several studies have reported the efficacy of phage therapy against P. aeruginosa .…”

The temperate Burkholderia phage AP3 of the Peduovirinae shows efficient antimicrobial activity against B. cenocepacia of the IIIA lineage

“…Phage AP3 was isolated from a natural wastewater treatment plant (irrigated fields) in Wroclaw (Poland) as previously described (Olszak et al 2015). AP3 was isolated from and propagated in the clinical isolate 7780 of B. cenocepacia IIIA lineage (Table 1).…”

“…Bacterial burden was determined by plating 10 μl of the serial dilutions onto LB agar and colonies were counted after 24 h. The injected larvae were incubated at 37 °C for 24 h; the numbers of dead larvae were counted and the LD 50 values determined and presented as a mean ( N  = 3 experiments). The in vivo phage treatment assay was conducted on a wax moth larvae model as described previously (Olszak et al 2015). To assess the antibacterial activity of AP3, larvae ( N  = 60) were sequentially injected with a 10-μl lethal dose of 10 5 cells of B. cenocepacia 7780 host strain and 10 μl of phage lysate at the titration equal to multiplicity of infection (MOI) 10.…”

“…Treatment with bacteriophages allows targeting pathogens that are resistant to conventional drugs without damaging the host’s natural flora. The efficacy of bacteriophages against CF pathogens has been shown in vivo using the Galleria mellonella insect model and various mouse pulmonary infection models (Seed and Dennis 2009; Carmody et al 2010; Lynch et al 2010; Saussereau et al 2014; Olszak et al 2015; Danis-Włodarczyk et al 2016). The synergistic effect of combining bacterial viruses with antibiotics may lead to higher production of phage progeny and increased phage activity, improving bacterial killing (Kamal and Dennis 2015).…”