Evaluation of biofilm-specific antimicrobial resistance genes in Pseudomonas aeruginosa isolates in Farabi Hospital

Saffari, Mahmood; Karami, Shabnam; Firoozeh, Farzaneh; Sehat, Mojtaba

doi:10.1099/jmm.0.000521

Cited by 25 publications

(15 citation statements)

References 31 publications

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“…Notably, laboratory evolution often lead to adapted strains having different physiological characteristics compared with their parent strains, which are usually related to a tness cost that is typically observed as a reduced bacterial growth rate [29,30]. Our results showed a statistically signi cant decreased growth rate and enhanced bio lm formation for DAP-R mutants, which were similar with previous ndings that the ability of bio lm formation was associated with increased resistance [31]. And the lethality and pathogenicity in Galleria mellonella larvae were also weakened for mutants.…”

Section: Discussionsupporting

confidence: 89%

Development of in Vitro Resistance to Daptomycin in Enterococcus Faecium and Estimation of Its Fitness Cost

Zeng

Chen

et al. 2020

Preprint

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BackgroundDaptomycin has broad-spectrum antibacterial activity against Gram-positive pathogens, but recent studies have revealed cases where daptomycin has failed to treat multidrug-resistant bacteria, such as vancomycin-resistant Enterococcus faecium. However, the resistance evolution of E. faecium to daptomycin in vitro and fitness cost remain unclear. In this study, we sought to analyze the resistance development and mechanism of E. faecium to datomycin, and futher to investigate the relationship between daptomycin resistance and fitness cost.MethodsTo investigate the development of daptomycin resistance in E. faecium, 6 daptomycin-susceptible (DAP-S) clinical isolates, including 3 vancomycin-resistant E. faecium (VRE) and 3 vancomycin-susceptible E. faecium (VSE), were exposured to daptomycin in vitro by serial passage experiment. Then the different resistance mechanisms of daptomycin-resistant (DAP-R) mutants were analyzed by polymerase chain reaction (PCR), cytochrome C binding assay and transmission electron microscopy. Furthermore, we also estimated the changes of fitness cost among each highly DAP-R mutants by bacterial growth curve measurement, in vitro competition experiments, infection model of Galleria mellonella larvae and biofilm formation assays.ResultsIn vitro, a total of 21 DAP-R mutants with minimal inhibitory concentration (MIC) of 4 to 512 μg/mL were obtained, and these mutants carried more than one mutation of LiaFSR and YycFG system encoding genes. More positive charges were detected among highly DAP-R mutants than parent isolates, and the cell walls of SC1174-D and SC1762-D mutants were remarkly thicker than those of the parent isolates. In comparison with parent isolates, besides, the growth, competition ability and virulence were significantly reduced, while the biofilm formation capacity was markedly elevated among each highly DAP-R mutants.ConclusionsOur findings suggest that E. faecium isolates are able to rapidly acquire DAP resistance in vitro through different dynamic resistance mechanisms, which often accompany by significant fitness cost. Intriguingly, DAP and glycopeptide antibiotics may present collateral-sensitivity during E. faecium acquired DAP resistance in vitro.

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Section: Discussionsupporting

confidence: 89%

Development of in Vitro Resistance to Daptomycin in Enterococcus Faecium and Estimation of Its Fitness Cost

Zeng

Chen

et al. 2020

Preprint

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“…An important factor contributing to the pathogenesis of P. aeruginosa is the formation of biofilms on biological surfaces, including within wounds (24,25). Antimicrobial resistance within biofilms results in a combination of factors that include slow infiltration of antibiotics through the biofilm and induction of lipid-modifying operons by extracellular matrix DNA (24)(25)(26)(27)(28)(29). We found that Pse-T2 significantly inhibited biofilm formation by E. coli, P. aeruginosa, and S. aureus, including their MDR strains (Fig.…”

Section: Discussionmentioning

confidence: 78%

Pse-T2, an Antimicrobial Peptide with High-Level, Broad-Spectrum Antimicrobial Potency and Skin Biocompatibility against Multidrug-Resistant Pseudomonas aeruginosa Infection

Kang

Seo

Luchian

et al. 2018

Antimicrob Agents Chemother

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Pseudin-2, isolated from the frog Pseudis paradoxa, exhibits potent antibacterial activity but also cytotoxicity. In an effort to develop clinically applicable antimicrobial peptides (AMPs), we designed pseudin-2 analogs with Lys substitutions, resulting in elevated amphipathic α-helical structure and cationicity. In addition, truncated analogs of pseudin-2 and Lys-substituted peptides were synthesized to produce linear 18-residue amphipathic α-helices, which were further investigated for their mechanism and functions. These truncated analogs exhibited higher antimicrobial activity and lower cytotoxicity than pseudin-2. In particular, Pse-T2 showed marked pore formation, permeabilization of the outer/inner bacterial membranes, and DNA binding. Fluorescence spectroscopy and scanning electron microscopy showed that Pse-T2 kills bacterial cells by disrupting membrane integrity. In vivo, wounds infected with multidrug-resistant (MDR) Pseudomonas aeruginosa healed significantly faster when treated with Pse-T2 than did untreated wounds or wounds treated with ciprofloxacin. Moreover, Pse-T2 facilitated infected-wound closure by reducing inflammation through suppression of interleukin-1β (IL-1β), IL-6, and tumor necrosis factor alpha (TNF-α). These data suggest that the small antimicrobial peptide Pse-T2 could be useful for future development of therapeutic agents effective against MDR bacterial strains.

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“…Safari et al (2017) evaluated the frequency of ndvB and Tssc1 genes among 92 P. aeruginosa isolates from patients with eye infections in Farabi Hospital, Tehran, Iran. All isolates could form biofilms and 96.7% and 90.2% harbored ndvB and Tssc1 genes, respectively, showing the significance of these genes in biofilm production [22]. The ndvB gene codes a glycosyltransferase essential for the formation of periplasmic glucose.…”

Section: Discussionmentioning

confidence: 99%

Frequency of cbrA, cbrB, ndvB, and phoBR Genes in Relation to Biofilm Formation in Pseudomonas aeruginosa Clinical Isolates

Riahy

Jahromi

Khaledi

et al. 2021

JoMMID

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Introduction: After Staphylococcus aureus and Escherichia coli, Pseudomonas aeruginosa is the third cause of hospital-acquired infection (HAI). This bacteria's ability to colonize in different environments, especially in hospitals and biofilm formation, has added to its impact as an HAI. The molecular mechanism of biofilm formation is not well understood, but several genes contribute to this phenomenon. This study investigates the frequency of cbrA, cbrB, phoBR, and ndvB genes in biofilm-forming P. aeruginosa isolates. Methods: Fifty P. aeruginosa clinical isolates were collected from various sources such as urine, ulcer, blood, secretions, and trachea in Milad Hospital, Tehran, from 2017 to 2018. Biofilm formation in the isolates was assessed by the microtiter plate assay, and the frequency of cbrA, cbrB, phoBR, and ndvB genes was investigated by PCR. Results: Among the 50 isolates, 44% were strong biofilm former, 34% moderate biofilm former, 12% weak biofilm former, and 10% did not form biofilms. PCR revealed a frequency of 94% for the cbrA gene, 78% for cbrB, 96% for ndvB, and 48% for phoBR. The coexistence of all four genes was 68% in strong biofilm former isolates, 41% in moderate biofilm former isolates, 37% in weak biofilm former, and zero in the isolates that formed no biofilm. Conclusion: The high frequency of ndvB and cbrA genes and the coexistence of ndvB and cbrB suggest the contribution of these genes in the biofilm formation of P. aeruginosa.

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Evaluation of biofilm-specific antimicrobial resistance genes in Pseudomonas aeruginosa isolates in Farabi Hospital

Abstract: Our results showed a considerable ability of biofilm production, as well as the occurrence of biofilm-specific antimicrobial resistance genes (ndvB and tssC1), in P. aeruginosa isolates from ocular infections in Farabi Hospital.

Cited by 25 publications

References 31 publications

Development of in Vitro Resistance to Daptomycin in Enterococcus Faecium and Estimation of Its Fitness Cost

Development of in Vitro Resistance to Daptomycin in Enterococcus Faecium and Estimation of Its Fitness Cost

Pse-T2, an Antimicrobial Peptide with High-Level, Broad-Spectrum Antimicrobial Potency and Skin Biocompatibility against Multidrug-Resistant Pseudomonas aeruginosa Infection

Frequency of cbrA, cbrB, ndvB, and phoBR Genes in Relation to Biofilm Formation in Pseudomonas aeruginosa Clinical Isolates

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