Determination of Acquired Resistance Profiles of Pseudomonas aeruginosa Isolates and Characterization of an Effective Bacteriocin-Like Inhibitory Substance (BLIS) Against These Isolates

Abstract

BackgroundThe emergence of pan-drug resistant strains (PDR) of Pseudomonas aeruginosa has led to renewed efforts to identify alternative agents, such as bacteriocins and bacteriocin-like inhibitory substances (BLISs).ObjectivesThe aims of this study were to determine the acquired resistance profiles of multidrug-resistant (MDR), extensively drug-resistant (XDR), and PDR P. aeruginosa isolates based on the revised definitions of the CDC and ECDC and to screen and characterize effective BLISs against these isolates.Patients and MaterialsIn a cross-sectional study, 96 P. aeruginosa strains were isolated during a 12-month period. The resistance profiles of these isolates were determined as MDR, XDR, and PDR, and the data were analyzed using WHONET5.6 software. A BLIS against the P. aeruginosa strains was characterized based on its physicochemical properties, size, growth curves, and production profiles.ResultsAmong the 96 isolates of P. aeruginosa, 2 (2.1%), 94 (97.9%), and 63 (65.6%) were non-MDR, MDR, and XDR, respectively, and 1 (1.1%) was PDR. The most effective antibiotics against these isolates were polymyxins and fosfomycin. A BLIS isolated from the P. aeruginosa DSH22 strain had potent activity against 92 (95.8%) of the 96 isolates. The BLIS was heat stable, (up to 100°C for 10 min), UV stable, and active within a pH range of 3 - 9. The activity of BLIS disappeared when treated with trypsin, proteinase K, and pepsin, indicating its proteinous nature. Based on its size (25 kDa), the BLIS may belong to the large colicin-like bacteriocin family. BLIS production started in the midexponential phase of growth, and the maximum level (2700 AU/mL) occurred in the late-stationary phase after 25 hours of incubation at 30°C.ConclusionsThis BLIS with broad-spectrum activity may be a potential agent for the treatment or control of drug-resistant strains of P. aeruginosa infection.

Incidence of Multidrug-Resistant, Extensively Drug-Resistant, and Pandrug-Resistant Pseudomonas aeruginosa Strains Isolated from Clinical Specimens

“…However, in foreign studies, lower prevalence rate has been reported [23][24][25] . None of the isolates showed PDR phenotype in the present and aforementioned studies; however, in the study of Shokri et al (2016), 1.1% of the isolates were PDR, and a high frequency of MDR (97.9%) and XDR (65.6%) phenotypes was observed [14] . In Ethiopia, among P. aeruginosa isolates, 6% were PDR, of which 91.8 and 9.8% were MDR and XDR, respectively [15] .…”

“…In agreement with a study from India, all the isolates were susceptible to fosfomycin (100%), but to other antibiotics, dissimilar susceptibility rates were observed [8] . In a study by Shokri et al (2016), the highest and lowest susceptibility rate was observed to ticarcillin-clavulanic acid (90%) and colistin (100%), respectively [14] . In a study conducted in Ethiopia, resistance to ceftazidime was reported as 91.8%, which is in line with the result of the present study [15] .…”

“…Considering the results of all the mentioned studies, including the present study, the susceptibility rate of P. aeruginosa isolates to antimicrobial agents and the incidence of drug-resistant isolates vary in different geographical regions. The prevalence rate of MDR, XDR, and PDR strains could be varied from 0 to 100, 2.3 to 87.5, and 0 to 6%, respectively [2,[13][14][15][18][19] . Differences in antibiotic use, geographical distribution of resistant strains, and history of antibiotic use may be the reasons for these differences [2] .…”

Antimicrobial resistance patterns of Pseudomonas aeruginosa isolated from canine clinical cases at a veterinary academic hospital in South Africa

“…Overall, 92% of P. aeruginosa isolates included in this study were MDR. Several other authors have also reported MDR levels of up to 97.9% amongst P. aeruginosa clinical isolates from humans (Shokri et al 2016). In contrast, other authors have reported low proportions of MDR-P. aeruginosa, ranging from 14% to 29% in human studies conducted in Pakistan and Saudi Arabia (Gill et al 2011;M.A.…”

Prevalence of Class I, II and III Integrons in Uropathogenic Escherichia Coli Strains Isolated from Patients with Urinary Tract Infection in Shiraz, Iran

“…Escherichia coli (E.coli) is the most predominant pathogen causing 80% of UTIs [1]. This pathogen acquires antibiotic resistance factors through chromosomal mutations, transposable plasmids, transposons, and integrons [4,5]. Integrons play a major role in spreading antibiotic resistance factors in these bacteria.…”