Polymyxin B nonapeptide potentiates the eradication of Gram-negative bacterial persisters

Microbiology Spectrum, Journal Year: 2024, Volume and Issue: 12(4)

Published: Feb. 23, 2024

ABSTRACT Antibiotic-resistant Gram-negative bacteria remain a globally leading cause of bacterial infection-associated mortality, and it is imperative to identify novel therapeutic strategies. Recently, the advantage using antibacterials selective against has been demonstrated with polymyxins that specifically target lipopolysaccharides bacteria. However, severe cytotoxicity limits their clinical use. Here, we demonstrate polymyxin B nonapeptide (PMBN), derivative without terminal amino acyl residue, can significantly enhance effectiveness commonly used antibiotics only persister cells. We show although PMBN itself does not exhibit antibacterial activity or well above 100-fold minimum inhibitory concentration B, increase potency co-treated antibiotics. also in combination other reduces frequency resistant mutant formation. Together, this work provides evidence utilities as potentiator for insights eradication cells during antibiotic treatment. IMPORTANCE The significance our study lies addressing problem antibiotic-resistant bacteria, which continue be global mortality associated infections. Therefore, identifying innovative approaches an urgent need. Recent research highlighted potential like polymyxins, use limited by cytotoxicity. This unveils (PMBN) enhancing Although cytotoxicity, remarkably treatment Moreover, combining emergence mutants. Our emphasizes utility decrease treatments

Language: Английский

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3D bioprinting of E. coli MG1655 biofilms on human lung epithelial cells for building complex in vitro infection models

Biofabrication, Journal Year: 2023, Volume and Issue: 15(3), P. 035019 - 035019

Published: May 26, 2023

Abstract Biofilm-associated infections are causing over half a million deaths each year, raising the requirement for innovative therapeutic approaches. For developing novel therapeutics against bacterial biofilm infections, complex in vitro models that allow to study drug effects on both pathogens and host cells as well their interaction under controlled, physiologically relevant conditions appear highly desirable. Nonetheless, building such is quite challenging because (1) rapid growth release of virulence factors may lead premature cell death (2) maintaining status suitable co-culture requires controlled environment. To approach problem, we chose 3D bioprinting. However, printing living biofilms defined shapes human models, bioinks with very specific properties. Hence, this work aims develop bioprinting method build robust infection models. Based rheology, printability growth, bioink containing 3% gelatin 1% alginate Luria-Bertani-medium was found optimal Escherichia coli MG1655 biofilms. Biofilm properties were maintained after printing, shown visually via microscopy techniques antibiotic susceptibility assays. Metabolic profile analysis bioprinted showed high similarity native After bronchial epithelial (Calu-3), shape printed even dissolution non-crosslinked bioink, while no cytotoxicity observed 24 h. Therefore, presented here provide platform comprising cells.

Language: Английский

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The artemisinin-induced dormant stages of Plasmodium falciparum exhibit hallmarks of cellular quiescence/senescence and drug resilience

Nature Communications, Journal Year: 2024, Volume and Issue: 15(1)

Published: Aug. 29, 2024

Recrudescent infections with the human malaria parasite, Plasmodium falciparum, presented traditionally major setback of artemisinin-based monotherapies. Although introduction artemisinin combination therapies (ACT) largely solved problem, ability to induce dormant parasites still poses an obstacle for current as well future chemotherapeutics. Here, we use a laboratory model induction P. falciparum and characterize their transcriptome, drug sensitivity profile, cellular ultrastructure. We show that dormancy requires ~ 5-day maturation process during which genome-wide gene expression pattern gradually transitions from ring-like state unique form. The transcriptome mature stage carries hallmarks both quiescence senescence, downregulation most functions associated growth development upregulation selected metabolic DNA repair. Moreover, is considerably more resistant antimalaria drugs compared fast-growing asexual stages. Finally, irregular ultrastructure further suggests properties this developmental life cycle should be taken into consideration by control strategies. Artemisinin can forms likely resulting in treatment failure. Here authors viability, sensitivities, after demonstrate senescence.

Language: Английский

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Non-Canonical Aspects of Antibiotics and Antibiotic Resistance

Antibiotics, Journal Year: 2024, Volume and Issue: 13(6), P. 565 - 565

Published: June 17, 2024

The understanding of antibiotic resistance, one the major health threats our time, is mostly based on dated and incomplete notions, especially in clinical contexts. “canonical” mechanisms action pharmacodynamics antibiotics, as well methods used to assess their activity upon bacteria, have not changed decades; same applies definition, acquisition, selective pressures, drivers resistance. As a consequence, strategies improve usage overcome resistance ultimately failed. This review gathers most “non-canonical” notions antibiotics resistance: from alternative limitations susceptibility testing wide variety lateral gene transfer mechanisms, ubiquity, societal factors maintaining Only by having “big picture” view problem can adequate harness be devised. These must global, addressing many aspects that drive increasing prevalence resistant bacteria aside use antibiotics.

Language: Английский

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Persistence and viable but non-culturable state induced by streptomycin in Erwinia amylovora

Frontiers in Microbiology, Journal Year: 2024, Volume and Issue: 15

Published: Feb. 21, 2024

Persister cell and viable but non-culturable (VBNC) state of bacteria are survival strategies against antibiotics various environmental stresses, respectively, they tend to be ignored in agriculture fields, even though can regain their abilities survive produce disease once those stresses disappear. This study was carried out determine whether persister VBNC Erwinia amylovora present after exposures streptomycin, the length persistence, steps needed decrease inoculum. cells were observed using biphasic killed growth curve for 4–8 h when late stationary phase E. cultured liquid medium containing streptomycin. maintained up 12 based on colony forming units (CFUs) colonies that grew mannitol glutamate yeast extract (MGY) streptomycin removed. The CFUs MGY lower than total count determined LIVE/DEAD Kit, suggesting might co-exist exposure However, h, did not continue grow 9 days, entered a at time remained persistent state. In addition, Redox Sensor Green staining method, presence both states confirmed only then became apparent. Furthermore, 24 damaged reduced culture distilled water with indicating uptake nutrients led prolonged state, which more likely treatments. addition sucrose oxytetracycline other sources did. Thus, inhibit spread fire blight, management techniques must consider hazards treatments induce dormancy, such as beyond development resistant strain.

Language: Английский

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Induced Burkholderia prophages detected from the hemoculture: a biomarker for Burkholderia pseudomallei infection

Frontiers in Microbiology, Journal Year: 2024, Volume and Issue: 15

Published: April 2, 2024

Bacteriophages (phages), viruses that infect bacteria, are found in abundance not only the environment but also human body. The use of phages for diagnosis melioidosis, a tropical infectious disease caused by Burkholderia pseudomallei , is emerging as promising novel approach, our understanding conditions under which prophages can be induced remains limited. Here, we first demonstrated isolation from hemocultures melioidosis patients. B. -positive hemoculture bottles were filtered to remove and then isolated purified spot double agar overlay plaque assays. Forty blood samples (hemoculture-confirmed melioidosis) tested, 30% samples. Transmission electron microscopy genome analysis phages, vB_HM387 vB_HM795, showed both Myoviruses. These two stable at pH 5–7 temperatures 25–37°C, suggesting their ability survive blood. sizes vB_HM795 36.3 44.0 kb, respectively. A phylogenetic indicated has homologs, Myovirus, heterogeneity key finding could patients highlights potential application phage-based assays detecting pathogen-derived biomarker infection.

Language: Английский

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The sleeping bacterium: shedding light on the resuscitation mechanism

European Biophysics Journal, Journal Year: 2025, Volume and Issue: unknown

Published: April 2, 2025

Language: Английский

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Unraveling Persistent Bacteria: Formation, Niches, and Eradication Strategies

Microbiological Research, Journal Year: 2025, Volume and Issue: 297, P. 128189 - 128189

Published: April 23, 2025

Language: Английский

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Observation of persister cell histories reveals diverse modes of survival in antibiotic persistence

eLife, Journal Year: 2025, Volume and Issue: 14

Published: May 13, 2025

Bacterial persistence is a phenomenon in which small fraction of isogenic bacterial cells survives lethal dose antibiotics. Although the refractoriness persistent cell populations has classically been attributed to growth-inactive generated before drug exposure, evidence accumulating that actively growing fractions can also generate persister cells. However, single-cell characterization history remains limited due extremely low frequencies persisters. Here, we visualize responses over one million individual wildtype Escherichia coli doses antibiotics, sampling from different growth phases and culture media into microfluidic device. We show when sampled exponentially were treated with ampicillin or ciprofloxacin, most persisters antibiotic treatment. Growing exhibited heterogeneous survival dynamics, including continuous fission L-form-like morphologies, responsive arrest, post-exposure filamentation. Incubating under stationary phase conditions increased both frequency probability non-growing ampicillin. Under however, all identified treatment, samples post-stationary culture. These results reveal diverse dynamics depend on types pre-exposure history.

Language: Английский

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Heterogeneous Distribution of Proton Motive Force in Nonheritable Antibiotic Resistance

mBio, Journal Year: 2023, Volume and Issue: 14(1)

Published: Jan. 4, 2023

Bacterial infections that are difficult to eradicate often treated by sequentially exposing the bacteria different antibiotics. Although effective, this approach can give rise epigenetic or other phenomena may help some cells adapt and tolerate Characteristics of such adapted dormancy low energy levels, which promote survival without lending long-term genetic resistance against In work, we quantified motility in Escherichia coli survived sequential exposure lethal doses populations transcriptional inhibition rifampicin, observed ~1 3 continued swimming for several hours presence concentrations ampicillin. As is powered proton motive force (PMF), our results suggested many retained a high PMF. Single-cell growth assays revealed high-PMF resuscitated divided upon removal ampicillin, just as low-PMF did, behavior reminiscent persister cells. Our consistent with notion clonal population employ multiple mechanisms antibiotic stresses. Variable PMF likely feature bet-hedging strategy: fraction cell lies dormant while retains be able swim out deleterious environment. IMPORTANCE survive stress due dormancy, favors nonheritable mutations acquisitions. On hand, less tolerant, helps uptake certain Here, flagellar an indirect measure had Despite disadvantage maintaining antibiotics, ~30% cells, evidenced their ability rapidly hours. These were idea tolerance arise via population.

Language: Английский

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