Two Novel Semisynthetic Lipoglycopeptides Active against Staphylococcus aureus Biofilms and Cells in Late Stationary Growth Phase

The increase in antibiotic resistance among Gram-positive bacteria underscores the urgent need to develop new antibiotics. New antibiotics should target actively growing susceptible bacteria that are resistant to clinically accepted antibiotics including bacteria that are not growing or are protected in a biofilm environment. In this paper, we compare the in vitro activities of two new semisynthetic glycopeptide antibiotics, MA79 and ERJ390, with two clinically used glycopeptide antibiotics—vancomycin and teicoplanin. The new antibiotics effectively killed not only exponentially growing cells of Staphylococcus aureus, but also cells in the stationary growth phase and biofilm.

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EttA is likely non-essential in Staphylococcus aureus persistence, fitness or resistance to antibiotics

BMC Microbiology ◽

10.1186/s12866-020-01970-w ◽

2020 ◽

Vol 20 (1) ◽

Author(s):

Michal Meir ◽

Anna Rozenblit ◽

Simona Fliger ◽

Yuval Geffen ◽

Daniel Barkan

Keyword(s):

Staphylococcus Aureus ◽

Antibiotic Resistance ◽

Growth Phase ◽

Cell Formation ◽

Stationary Growth Phase ◽

Clinical Isolates ◽

Beta Lactam ◽

Stationary Growth ◽

Mechanisms Of Persistence

Abstract Background Tolerance to antibiotics and persistence are associated with antibiotic treatment failures, chronic-relapsing infections, and emerging antibiotic resistance in various bacteria, including Staphylococcus aureus. Mechanisms of persistence are largely unknown, yet have been linked to physiology under low-ATP conditions and the metabolic-inactive state. EttA is an ATP-binding cassette protein, linked in Eschrechia coli to ribosomal hibernation and fitness in stationary growth phase, yet its role in S. aureus physiology is unknown. Results Using whole genome sequencing (WGS) of serial clinical isolates, we identified an EttA-negative S. aureus mutant (ettAstop), and its isogenic wild-type counterpart. We used these two isogenic clones to investigate the role of ettA in S. aureus physiology in starvation and antibiotic stress, and test its role in persistence and antibiotic tolerance. ettAstop and its WT counterpart were similar in their antibiotic resistance profiles to multiple antibiotics. Population dynamics of ettAstop and the WT were similar in low-nutrient setting, with similar recovery from stationary growth phase or starvation. Supra-bacteriocidal concentration of cefazolin had the same killing effect on ettAstop and WT populations, with no difference in persister formation. Conclusions Lack of ettA does not affect S. aureus antibiotic resistance, beta-lactam tolerance, resilience to starvation or fitness following starvation. We conclude the role of ettA in S. aureus physiology is limited or redundant with another, unidentified gene. WGS of serial clinical isolates may enable investigation of other single genes involved in S. aureus virulence, and specifically persister cell formation.

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In Vitro and In Vivo Activities of DA-7867, a New Oxazolidinone, against Aerobic Gram-Positive Bacteria

Antimicrobial Agents and Chemotherapy ◽

10.1128/aac.49.6.2498-2500.2005 ◽

2005 ◽

Vol 49 (6) ◽

pp. 2498-2500 ◽

Cited By ~ 7

Author(s):

Eun Jeong Yoon ◽

Yeong Woo Jo ◽

Sung Hak Choi ◽

Tae Ho Lee ◽

Jae Keol Rhee ◽

...

Keyword(s):

Staphylococcus Aureus ◽

Streptococcus Pneumoniae ◽

Gram Positive ◽

Methicillin Resistant ◽

Gram Positive Bacteria ◽

Vancomycin Resistant Enterococci ◽

Infection Models ◽

Vancomycin Resistant

ABSTRACT In vitro and in vivo activities of DA-7867 were assessed against methicillin-resistant Staphylococcus aureus, vancomycin-resistant enterococci, and penicillin-resistant Streptococcus pneumoniae. All isolates were inhibited by DA-7867 at ≤0.78 μg/ml, a four-times-lower concentration than that of inhibition by linezolid. For murine infection models, DA-7867 also exhibited greater efficacy than linezolid against all isolates tested.

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A Novel Point Mutation Promotes Growth Phase-Dependent Daptomycin Tolerance in Staphylococcus aureus

Antimicrobial Agents and Chemotherapy ◽

10.1128/aac.00643-15 ◽

2015 ◽

Vol 59 (9) ◽

pp. 5366-5376 ◽

Cited By ~ 46

Author(s):

Lukas Mechler ◽

Alexander Herbig ◽

Kerstin Paprotka ◽

Martin Fraunholz ◽

Kay Nieselt ◽

...

Keyword(s):

Staphylococcus Aureus ◽

Point Mutation ◽

Growth Phase ◽

Drug Tolerance ◽

Stationary Growth Phase ◽

Cellular Functions ◽

Upstream Gene ◽

Content Type ◽

High Degree

ABSTRACTRecalcitrance of genetically susceptible bacteria to antibiotic killing is a hallmark of bacterial drug tolerance. This phenomenon is prevalent in biofilms, persisters, and also planktonic cells and is associated with chronic or relapsing infections with pathogens such asStaphylococcus aureus. Here we report thein vitroevolution of anS. aureusstrain that exhibits a high degree of nonsusceptibility to daptomycin as a result of cyclic challenges with bactericidal concentrations of the drug. This phenotype was attributed to stationary growth phase-dependent drug tolerance and was clearly distinguished from resistance. The underlying genetic basis was revealed to be an adaptive point mutation in the putative inorganic phosphate (Pi) transporter genepitA. Drug tolerance caused by this allele, termedpitA6, was abrogated when the upstream genepitRwas inactivated. Enhanced tolerance toward daptomycin, as well as the acyldepsipeptide antibiotic ADEP4 and various combinations of other drugs, was accompanied by elevated intracellular concentrations of Piand polyphosphate, which may reversibly interfere with critical cellular functions. The evolved strain displayed increased rates of survival within human endothelial cells, demonstrating the correlation of intracellular persistence and drug tolerance. These findings will be useful for further investigations ofS. aureusdrug tolerance, toward the development of additional antipersister compounds and strategies.

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In vitro activity of the trinem sanfetrinem (GV104326) against gram-positive organisms.

Antimicrobial Agents and Chemotherapy ◽

10.1128/aac.40.9.2142 ◽

1996 ◽

Vol 40 (9) ◽

pp. 2142-2146 ◽

Cited By ~ 11

Author(s):

K V Singh ◽

T M Coque ◽

B E Murray

Keyword(s):

Staphylococcus Aureus ◽

Vitro Activity ◽

In Vitro Activity ◽

Gram Positive ◽

Gram Positive Bacteria ◽

Microdilution Method ◽

Broth Microdilution Method ◽

Gentamicin Resistance ◽

High Level

The in vitro activity of the trinem sanfetrinem (formerly GV104326) (GV) was compared with that of vancomycin, ampicillin, and/or nafcillin against 287 gram-positive bacteria, including methicillin-resistant Staphylococcus aureus and multiresistant enterococci, by the agar and microbroth dilution methods. GV demonstrated 2 to 16 times more activity than ampicillin and nafcillin against the majority of these organisms. The MIC range of GV was 16 to 64 micrograms/ml for 19 Enterococcus faecium strains that were highly resistant to ampicillin (ampicillin MIC range, 64 to 512 micrograms/ml) and vancomycin resistant and 0.25 to 32 micrograms/ml for resistant Rhodococcus spp. Similar activities (+/-1 dilution) were observed by either the agar or the broth microdilution method. GV demonstrated bactericidal activity against a beta-lactamase-producing Enterococcus faecalis strain and against two methicillin-susceptible Staphylococcus aureus strains in 10(5)-CFU/ml inocula. Synergy between GV and gentamicin was observed against an E. faecalis strain that lacked high-level gentamicin resistance. The activity of GV suggests this compound warrants further study.

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The Effect of Adding Blood on the Virulence Genes Expression of Staphylococcus aureus in Exponential and Stationary Growth Phase

Jundishapur Journal of Microbiology ◽

10.5812/jjm.14380 ◽

2017 ◽

Vol 10 (6) ◽

Cited By ~ 1

Author(s):

Hadi Koohsari ◽

Ezzat Allah Ghaemi ◽

Noor Amir Mozaffari ◽

Abdolvahhab Moradi ◽

Maryam Sadegh-Sheshpoli ◽

...

Keyword(s):

Staphylococcus Aureus ◽

Growth Phase ◽

Virulence Genes ◽

Stationary Growth Phase ◽

Stationary Growth ◽

Genes Expression

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Postantibiotic Suppression of Growth of Erythromycin A-Susceptible and -Resistant Gram-Positive Bacteria by the Ketolides Telithromycin (HMR 3647) and HMR 3004

Antimicrobial Agents and Chemotherapy ◽

10.1128/aac.44.6.1749-1753.2000 ◽

2000 ◽

Vol 44 (6) ◽

pp. 1749-1753 ◽

Cited By ~ 17

Author(s):

Wendy J. Munckhof ◽

Glenn Borlace ◽

John D. Turnidge

Keyword(s):

Staphylococcus Aureus ◽

Streptococcus Pneumoniae ◽

Streptococcus Pyogenes ◽

Gram Positive ◽

Gram Positive Bacteria ◽

Resistant Strains ◽

Erythromycin A

ABSTRACT We investigated the in vitro postantibiotic effects (PAEs) of the ketolides telithromycin (HMR 3647) and HMR 3004 and analyzed the results using the sigmoid E max model. Mean maximum telithromycin PAEs against erythromycin A-susceptible strains of Staphylococcus aureus, Streptococcus pyogenes, and Streptococcus pneumoniae were 3.7, 8.9, and 9.7 h, respectively, while maximum PAEs for erythromycin A-resistant strains were much shorter. Mean maximum HMR 3004 PAEs were 3.2 to 4.4 h for all species.

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Anti-staphylococcal activity and mode of action of thioridazine photoproducts

Scientific Reports ◽

10.1038/s41598-020-74752-z ◽

2020 ◽

Vol 10 (1) ◽

Author(s):

Tatiana Tozar ◽

Sofia Santos Costa ◽

Ana-Maria Udrea ◽

Viorel Nastasa ◽

Isabel Couto ◽

...

Keyword(s):

Staphylococcus Aureus ◽

Antibiotic Resistance ◽

Molecular Docking ◽

Infectious Diseases ◽

Molecular Mechanisms ◽

Dynamic Surface Tension ◽

Docking Studies ◽

Gram Positive ◽

Dynamic Surface ◽

Gram Positive Bacteria

Abstract Antibiotic resistance became an increasing risk for population health threatening our ability to fight infectious diseases. The objective of this study was to evaluate the activity of laser irradiated thioridazine (TZ) against clinically-relevant bacteria in view to fight antibiotic resistance. TZ in ultrapure water solutions was irradiated (1–240 min) with 266 nm pulsed laser radiation. Irradiated solutions were characterized by UV–Vis and FTIR absorption spectroscopy, thin layer chromatography, laser-induced fluorescence, and dynamic surface tension measurements. Molecular docking studies were made to evaluate the molecular mechanisms of photoproducts action against Staphylococcus aureus and MRSA. More general, solutions were evaluated for their antimicrobial and efflux inhibitory activity against a panel of bacteria of clinical relevance. We observed an enhanced antimicrobial activity of TZ photoproducts against Gram-positive bacteria. This was higher than ciprofloxacin effects for methicillin- and ciprofloxacin-resistant Staphylococcus aureus. Molecular docking showed the Penicillin-binding proteins PBP3 and PBP2a inhibition by sulforidazine as a possible mechanism of action against Staphylococcus aureus and MRSA strains, respectively. Irradiated TZ reveals possible advantages in the treatment of infectious diseases produced by antibiotic-resistant Gram-positive bacteria. TZ repurposing and its photoproducts, obtained by laser irradiation, show accelerated and low-costs of development if compared to chemical synthesis.

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RING finger E3 ligase PPP1R11 regulates TLR2 signaling and innate immunity

eLife ◽

10.7554/elife.18496 ◽

2016 ◽

Vol 5 ◽

Cited By ~ 11

Author(s):

Alison C McKelvey ◽

Travis B Lear ◽

Sarah R Dunn ◽

John Evankovich ◽

James D Londino ◽

...

Keyword(s):

Staphylococcus Aureus ◽

Innate Immunity ◽

Ring Finger ◽

E3 Ligase ◽

Gram Positive ◽

Gram Positive Bacteria ◽

Toll Like Receptor 2 ◽

Ligand Stimulation

Toll-like receptor 2 (TLR2) is a pattern recognition receptor that recognizes many types of PAMPs that originate from gram-positive bacteria. Here we describe a novel mechanism regulating TLR2 protein expression and subsequent cytokine release through the ubiquitination and degradation of the receptor in response to ligand stimulation. We show a new mechanism in which an uncharacterized RING finger E3 ligase, PPP1R11, directly ubiquitinates TLR2 both in vitro and in vivo, which leads to TLR2 degradation and disruption of the signaling cascade. Lentiviral gene transfer or knockdown of PPP1R11 in mouse lungs significantly affects lung inflammation and the clearance of Staphylococcus aureus. There is a negative correlation between PPP1R11 and TLR2 levels in white blood cell samples isolated from patients with Staphylococcus aureus infections. These results suggest that PPP1R11 plays an important role in regulating innate immunity and gram-positive bacterial clearance by functioning, in part, through the ubiquitination and degradation of TLR2.

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Bacillus anthracis and Bacillus cereus PcrA Helicases Can Support DNA Unwinding and In Vitro Rolling-Circle Replication of Plasmid pT181 of Staphylococcus aureus

Journal of Bacteriology ◽

10.1128/jb.186.7.2195-2199.2004 ◽

2004 ◽

Vol 186 (7) ◽

pp. 2195-2199 ◽

Cited By ~ 27

Author(s):

Syam P. Anand ◽

Poulami Mitra ◽

Asma Naqvi ◽

Saleem A. Khan

Keyword(s):

Staphylococcus Aureus ◽

Bacillus Cereus ◽

Bacillus Anthracis ◽

Broad Host Range ◽

Gram Positive ◽

Rolling Circle ◽

Initiator Protein ◽

Gram Positive Bacteria ◽

Plasmid Pt181

ABSTRACT Replication of rolling-circle replicating (RCR) plasmids in gram-positive bacteria requires the unwinding of initiator protein-nicked plasmid DNA by the PcrA helicase. In this report, we demonstrate that heterologous PcrA helicases from Bacillus anthracis and Bacillus cereus are capable of unwinding Staphylococcus aureus plasmid pT181 from the initiator-generated nick and promoting in vitro replication of the plasmid. These helicases also physically interact with the RepC initiator protein of pT181. The ability of PcrA helicases to unwind noncognate RCR plasmids may contribute to the broad-host-range replication and dissemination of RCR plasmids in gram-positive bacteria.

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