Evaluation of Antibacterial Effects of Matrix-Induced Silver Ions against Antibiotic-Resistant ESKAPE Pathogens

Ya-Chi Huang; Tsung-Ying Yang; Bo-Xuan Chen; Jung-Chang Kung; Chi-Jen Shih

doi:10.3390/ph14111094

Evaluation of Antibacterial Effects of Matrix-Induced Silver Ions against Antibiotic-Resistant ESKAPE Pathogens

Pharmaceuticals (Basel). 2021 Oct 28;14(11):1094. doi: 10.3390/ph14111094.

Authors

Ya-Chi Huang¹, Tsung-Ying Yang^{2

3}, Bo-Xuan Chen², Jung-Chang Kung^{4

5

6}, Chi-Jen Shih^{1

7}

Affiliations

¹ Department of Fragrance and Cosmetic Science, College of Pharmacy, Kaohsiung Medical University, Kaohsiung 807, Taiwan.
² Department of Medical Laboratory Science and Biotechnology, College of Health Sciences, Kaohsiung Medical University, Kaohsiung 807, Taiwan.
³ Center for Liquid Biopsy and Cohort Research, Kaohsiung Medical University, Kaohsiung 807, Taiwan.
⁴ School of Dentistry, College of Dental Medicine, Kaohsiung Medical University, Kaohsiung 807, Taiwan.
⁵ Department of Dentistry, Division of Family Dentistry, Kaohsiung Medical University Hospital, Kaohsiung 807, Taiwan.
⁶ Department of Dentistry, Kaohsiung Municipal Ta-Tung Hospital, Kaohsiung 801, Taiwan.
⁷ Department of Medical Research, Kaohsiung Medical University Hospital, Kaohsiung 807, Taiwan.

Abstract

Recently, drug-resistant bacterial infections, especially ESKAPE pathogens (Enterococcus faecium, Staphylococcus aureus, Klebsiella pneumoniae, Acinetobacter baumannii, Pseudomonas aeruginosa, and Enterobacter spp.), have become a critical health issue worldwide, highlighting the emerging need for novel antibacterial agents. In this study, silver nanoparticles were extracted from silver-containing mesoporous bioactive glass (MBG-Ag) using four different matrixes, including water, phosphate buffer saline (PBS), tryptic soy broth (TSB), and taurine (Tau). The inductively coupled plasma-mass spectrometer (ICP-MS) results demonstrated that the silver concentration of Tau-Ag was the highest among the four matrixes. The Tau-Ag was also observed to have 87.35% silver ions in its X-ray photoelectron spectrometer (XPS) spectra. The micrograph of transmission electron microscope (TEM) displayed a uniform distribution of silver nanoparticles, which was confined in a smaller size compared to that in TSB-Ag. Moreover, the peak shifts observed in the Fourier-transform infrared spectrometer (FTIR) spectrum implied that the -SO₃^2- and -NH groups in taurine may interact with silver. A low cytotoxicity was noted for Tau-Ag, with approximately 70% of cells surviving at 0.63 mg/mL. Compared to the other three matrix-induced silver agents, Tau-Ag represented a better antibacterial effect against methicillin-resistant Staphylococcus aureus, with a minimum inhibitory concentration (MIC) value of 0.63 mg/mL and a postponed growth of 0.31 mg/mL observed. Further antibacterial examinations illustrated the presence of remarkable antibacterial activities against vancomycin-resistant Enterococcus feacium, carbapenem-resistant Klebsiella pneumoniae, carbapenem-resistant Acinetobacter baumannii, and carbapenem-resistant Pseudomonas aeruginosa. Given our observations and multiple bioactive functions of taurine (prevent patients from inflammation and oxidative-stress injuries), we anticipate that taurine matrix-induced silver ions would be a biomedical material with a high potential for combatting drug-resistant ESKAPE pathogens.

Keywords: ESKAPE pathogens; antibacterial agent; carbapenem resistance; matrix induction; methicillin resistance; silver ion; silver-containing mesoporous bioactive glass; vancomycin resistance.

Abstract

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