Novel Antimicrobial Agents Against Multi-drug-resistant Gram-positive Bacteria: An Overview

ABSTRACTLeguminous plants establish symbiosis with nitrogen-fixing alpha- and betaproteobacteria, collectively called rhizobia, which provide combined nitrogen to support plant growth. Members of the inverted repeat-lacking clade of legumes impose terminal differentiation on their endosymbiotic bacterium partners with the help of the nodule-specific cysteine-rich (NCR) peptide family composed of close to 600 members. Among the few tested NCR peptides, cationic ones had antirhizobial activity measured by reduction or elimination of the CFU and uptake of the membrane-impermeable dye propidium iodide. Here, the antimicrobial spectrum of two of these peptides, NCR247 and NCR335, was investigated, and their effect on the transcriptome of the natural targetSinorhizobium melilotiwas characterized. Both peptides were able to kill quickly a wide range of Gram-negative and Gram-positive bacteria; however, their spectra were only partially overlapping, and differences were found also in their efficacy on given strains, indicating that the actions of NCR247 and NCR335 might be similar though not identical. Treatment ofS. meliloticultures with either peptide resulted in a quick downregulation of genes involved in basic cellular functions, such as transcription-translation and energy production, as well as upregulation of genes involved in stress and oxidative stress responses and membrane transport. Similar changes provoked mainly in Gram-positive bacteria by antimicrobial agents were coupled with the destruction of membrane potential, indicating that it might also be a common step in the bactericidal actions of NCR247 and NCR335.

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Emerging Resistance to Antimicrobial Agents in Gram-Positive Bacteria

Drugs ◽

10.2165/00003495-199600511-00004 ◽

1996 ◽

Vol 51 (Supplement 1) ◽

pp. 6-12 ◽

Cited By ~ 86

Author(s):

Martin G. Cormican ◽

Ronald N. Jones

Keyword(s):

Antimicrobial Agents ◽

Gram Positive ◽

Gram Positive Bacteria

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Ribosome Rescue Pathways in Bacteria

Frontiers in Microbiology ◽

10.3389/fmicb.2021.652980 ◽

2021 ◽

Vol 12 ◽

Author(s):

Claudia Müller ◽

Caillan Crowe-McAuliffe ◽

Daniel N. Wilson

Keyword(s):

Messenger Rna ◽

Pathogenic Bacteria ◽

Antimicrobial Agents ◽

Polypeptide Chain ◽

Drug Resistant ◽

Bacterial Survival ◽

Gram Positive Bacteria ◽

Small Protein B ◽

Recent Developments ◽

Rescue System

Ribosomes that become stalled on truncated or damaged mRNAs during protein synthesis must be rescued for the cell to survive. Bacteria have evolved a diverse array of rescue pathways to remove the stalled ribosomes from the aberrant mRNA and return them to the free pool of actively translating ribosomes. In addition, some of these pathways target the damaged mRNA and the incomplete nascent polypeptide chain for degradation. This review highlights the recent developments in our mechanistic understanding of bacterial ribosomal rescue systems, including drop-off, trans-translation mediated by transfer-messenger RNA and small protein B, ribosome rescue by the alternative rescue factors ArfA and ArfB, as well as Bacillus ribosome rescue factor A, an additional rescue system found in some Gram-positive bacteria, such as Bacillus subtilis. Finally, we discuss the recent findings of ribosome-associated quality control in particular bacterial lineages mediated by RqcH and RqcP. The importance of rescue pathways for bacterial survival suggests they may represent novel targets for the development of new antimicrobial agents against multi-drug resistant pathogenic bacteria.

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Construction of Leaderless-Bacteriocin-Producing Bacteriophage Targeting E. coli and Neighboring Gram-Positive Pathogens

Microbiology Spectrum ◽

10.1128/spectrum.00141-21 ◽

2021 ◽

Author(s):

Yoshimitsu Masuda ◽

Shun Kawabata ◽

Tatsuya Uedoi ◽

Ken-ichi Honjoh ◽

Takahisa Miyamoto

Keyword(s):

Antimicrobial Agents ◽

Host Strain ◽

Phage Resistance ◽

Gram Positive ◽

Gram Negative ◽

E Coli ◽

Gram Positive Bacteria ◽

T7 Phage

We demonstrated that we could combine LLB and phage to construct promising novel antimicrobial agents, LLB-phage. The first LLB-phage, lnqQ -T7 phage, can control the growth of both the Gram-negative host strain and neighboring Gram-positive bacteria while preventing the emergence of phage resistance in the host strain.

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Design, synthesis and biological evaluations of novel 7-[3-(1-aminocycloalkyl)pyrrolidin-1-yl]-6-desfluoro-8-methoxyquinolones with potent antibacterial activity against multi-drug resistant Gram-positive bacteria

Bioorganic & Medicinal Chemistry ◽

10.1016/j.bmc.2009.08.026 ◽

2009 ◽

Vol 17 (19) ◽

pp. 6879-6889 ◽

Cited By ~ 11

Author(s):

Rie Miyauchi ◽

Katsuhiro Kawakami ◽

Masao Ito ◽

Norikazu Matsuhashi ◽

Hitoshi Ohki ◽

...

Keyword(s):

Antibacterial Activity ◽

Drug Resistant ◽

Gram Positive ◽

Design Synthesis ◽

Gram Positive Bacteria

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Emerging Treatment Options for Infections by Multidrug-Resistant Gram-Positive Microorganisms

Microorganisms ◽

10.3390/microorganisms8020191 ◽

2020 ◽

Vol 8 (2) ◽

pp. 191 ◽

Cited By ~ 4

Author(s):

Despoina Koulenti ◽

Elena Xu ◽

Andrew Song ◽

Isaac Yin Sum Mok ◽

Drosos E. Karageorgopoulos ◽

...

Keyword(s):

Safety Profile ◽

Bacterial Infections ◽

Antimicrobial Agents ◽

Treatment Options ◽

Multidrug Resistant ◽

Current Treatment ◽

Multi Drug Resistance ◽

Gram Positive ◽

Treatment Regimens ◽

Gram Positive Bacteria

Antimicrobial agents are currently the mainstay of treatment for bacterial infections worldwide. However, due to the increased use of antimicrobials in both human and animal medicine, pathogens have now evolved to possess high levels of multi-drug resistance, leading to the persistence and spread of difficult-to-treat infections. Several current antibacterial agents active against Gram-positive bacteria will be rendered useless in the face of increasing resistance rates. There are several emerging antibiotics under development, some of which have been shown to be more effective with an improved safety profile than current treatment regimens against Gram-positive bacteria. We will extensively discuss these antibiotics under clinical development (phase I-III clinical trials) to combat Gram-positive bacteria, such as Staphylococcus aureus, Enterococcus faecium and Streptococcus pneumoniae. We will delve into the mechanism of actions, microbiological spectrum, and, where available, the pharmacokinetics, safety profile, and efficacy of these drugs, aiming to provide a comprehensive review to the involved stakeholders.

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In Vitro Activity of Eravacycline against Gram-Positive Bacteria Isolated in Clinical Laboratories Worldwide from 2013 to 2017

Antimicrobial Agents and Chemotherapy ◽

10.1128/aac.01715-19 ◽

2019 ◽

Vol 64 (3) ◽

Cited By ~ 1

Author(s):

Ian Morrissey ◽

Stephen Hawser ◽

Sibylle H. Lob ◽

James A. Karlowsky ◽

Matteo Bassetti ◽

...

Keyword(s):

Antimicrobial Agents ◽

Clinical Isolates ◽

Gram Positive ◽

Content Type ◽

Gram Positive Bacteria ◽

Microdilution Method ◽

Clinical Laboratories ◽

Broth Microdilution Method ◽

Doubling Dilution

ABSTRACT Eravacycline is a novel, fully synthetic fluorocycline antibiotic being developed for the treatment of serious infections, including those caused by resistant Gram-positive pathogens. Here, we evaluated the in vitro activities of eravacycline and comparator antimicrobial agents against a recent global collection of frequently encountered clinical isolates of Gram-positive bacteria. The CLSI broth microdilution method was used to determine in vitro MIC data for isolates of Enterococcus spp. (n = 2,807), Staphylococcus spp. (n = 4,331), and Streptococcus spp. (n = 3,373) isolated primarily from respiratory, intra-abdominal, urinary, and skin specimens by clinical laboratories in 37 countries on three continents from 2013 to 2017. Susceptibilities were interpreted using both CLSI and EUCAST breakpoints. There were no substantive differences (a >1-doubling-dilution increase or decrease) in eravacycline MIC90 values for different species/organism groups over time or by region. Eravacycline showed MIC50 and MIC90 results of 0.06 and 0.12 μg/ml, respectively, when tested against Staphylococcus aureus, regardless of methicillin susceptibility. The MIC90 values of eravacycline for Staphylococcus epidermidis and Staphylococcus haemolyticus were equal (0.5 μg/ml). The eravacycline MIC90s for Enterococcus faecalis and Enterococcus faecium were 0.06 μg/ml and were within 1 doubling dilution regardless of the vancomycin susceptibility profile. Eravacycline exhibited MIC90 results of ≤0.06 μg/ml when tested against Streptococcus pneumoniae and beta-hemolytic and viridans group streptococcal isolates. In this surveillance study, eravacycline demonstrated potent in vitro activity against frequently isolated clinical isolates of Gram-positive bacteria (Enterococcus, Staphylococcus, and Streptococcus spp.), including isolates collected over a 5-year period (2013 to 2017), underscoring its potential benefit in the treatment of infections caused by common Gram-positive pathogens.

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