Dual-Function Potentiation by PEG-BPEI Restores Activity of Carbapenems and Penicillins against Carbapenem-Resistant Enterobacteriaceae

Abstract

The rise of life-threatening carbapenem-resistant Enterobacteriaceae (CRE) infections has become a critical medical threat. Some of the most dangerous CRE bacteria can produce enzymes that degrade a wide range of antibiotics, including carbapenems and β-lactams. Infections by CRE have a high mortality rate, and survivors can have severe morbidity from treatment with toxic last-resort antibiotics. CRE have mobile genetic elements that transfer resistance genes to other species. These bacteria also circulate throughout the healthcare system. The mobility and spread of CRE need to be curtailed, but these goals are impeded by having few agents that target a limited range of pathogenic CRE species. Against CRE possessing the metallo-β-lactamase NDM-1, Klebsiella pneumoniae ATCC BAA-2146 and Escherichia coli ATCC BAA-2452, the potentiation of meropenem and imipenem is possible with low-molecular weight branched polyethylenimine (600 Da BPEI) and its poly­(ethylene glycol) (PEG)­ylated derivative (PEG-BPEI) that has a low in vivo toxicity. The mechanism of action is elucidated with fluorescence assays of drug influx and isothermal calorimetry data showing the chelation of essential Zn2+ ions. These results suggested that 600 Da BPEI and PEG-BPEI may also improve the uptake of antibiotics and β-lactamase inhibitors. Indeed, the CRE E. coli strain is rendered susceptible to the combination of piperacillin and tazobactam. These results expand the possible utility of 600 Da BPEI potentiators, where previously we have demonstrated the ability to improve antibiotic efficacy against antibiotic resistant clinical isolates of Pseudomonas aeruginosa, Staphylococcus aureus, and Staphylococcus epidermidis.

Eradicating Biofilms of Carbapenem‐Resistant Enterobacteriaceae by Simultaneously Dispersing the Biomass and Killing Planktonic Bacteria with PEGylated Branched Polyethyleneimine

“…This leads to the development of multi‐drug resistant CRE [23] . In addition to the anti‐biofilm results presented in this manuscript, PEG‐BPEI has been shown to render the CRE strains K. pneumoniae ATCC BAA‐2146 and E. coli ATCC BAA‐2452 more susceptible to the carbapenem antibiotics meropenem and imipenem by reducing the MIC to values below the resistance breakpoints [10d] . Because of these results, and the ability of PEG350‐BPEI to disrupt biofilms and antibiotic resistance in Pseudomonas aeruginosa and Staphylococci , [11,25] new technological pipelines are opened to address drug‐resistant pathogens and biofilm formation that place a significant burden on the health care system [24d,26]…”

“…The reasons for this observation are unclear. Nevertheless, the aim of this work was to disperse E. coli biofilms with the same agent that disables CRE antibiotic resistance mechanisms [10d] . Additionally, in a clinical setting, wounds are likely to be contaminated with multiple bacterial strains and/or species.…”

“…This compound addresses medical needs highlighted in the 2020–2025 National Action Plan for Combating Antibiotic Resistant Bacteria, [19] which calls for infection prevention through new strategies with innovative products and decolonizing agents to slow the emergence and spread of antibiotic resistance genes and antibiotic‐resistant pathogens. The action plan was developed even though there are many options to kill CRE pathogens in the planktonic state [6b,20,10a,b,d] such as polymyxins, colistin, aminoglycosides, fosfomycin, and tigecycline [1,21] . Combination therapy takes advantage of synergy amongst antimicrobial compounds [1] .…”

Neutralizing Staphylococcus aureus PAMPs that Trigger Cytokine Release from THP-1 Monocytes

“… − ,− ,− However, the toxicity concerns arising from the presence of primary amines 600 Da BPEI are significant and need to be addressed. The in vivo toxicity concerns are resolved by covalently conjugating a low-molecular-weight polyethylene glycol (350 MW PEG) moiety to 600 Da BPEI, resulting in PEG-BPEI (Figure bottom). ,− Additionally, we have shown that the PEGylated derivative possesses the potentiator characteristics of BPEI against the MDR strains and their biofilms. ,− Regardless of the BPEI ability to facilitate the uptake of drugs and lower drug influx barriers as an antibiotic potentiator against bacterial biofilms and planktonic cells, therapeutic benefits of 600 Da BPEI and PEG-BPEI can be expanded. In this work, we continue to investigate 600 Da BPEI and its PEGylated derivative as anti-PAMP molecules to help mitigate the overproduction of inflammatory response.…”

Antibiofilm Activity of PEGylated Branched Polyethylenimine

“…We have previously identified low molecular weight 600 Da branched polyethylenimine (600 Da BPEI) as a broad-spectrum antibiotic potentiator that can overcome antibiotic resistance and restore the susceptibility of MDR strains of Gram-positive and Gram-negative bacteria to existing antibiotics. − We have also reported its antibiofilm properties and suggested that the cationic nature of BPEI enables electrostatic interactions with anionic targets in biofilms. However, the primary amines of 600 Da BPEI create cytotoxicity concerns that cannot be overlooked.…”