The Effects of Silver Sulfadiazine on Methicillin-Resistant <i>Staphylococcus aureus</i> Biofilms

Methicillin-resistant <i>Staphylococcus aureus</i> (MRSA), the most commonly detected drug-resistant microbe in hospitals, adheres to substrates and forms biofilms that are resistant to immunological responses and antimicrobial drugs. Currently, there is a need to develop alternative app...

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Bibliographic Details
Main Authors: Yutaka Ueda, Motoyasu Miyazaki, Kota Mashima, Satoshi Takagi, Shuuji Hara, Hidetoshi Kamimura, Shiro Jimi
Format: Article
Language:English
Published: MDPI AG 2020-10-01
Series:Microorganisms
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Online Access:https://www.mdpi.com/2076-2607/8/10/1551
Description
Summary:Methicillin-resistant <i>Staphylococcus aureus</i> (MRSA), the most commonly detected drug-resistant microbe in hospitals, adheres to substrates and forms biofilms that are resistant to immunological responses and antimicrobial drugs. Currently, there is a need to develop alternative approaches for treating infections caused by biofilms to prevent delays in wound healing. Silver has long been used as a disinfectant, which is non-specific and has relatively low cytotoxicity. Silver sulfadiazine (SSD) is a chemical complex clinically used for the prevention of wound infections after injury. However, its effects on biofilms are still unclear. In this study, we aimed to analyze the mechanisms underlying SSD action on biofilms formed by MRSA. The antibacterial effects of SSD were a result of silver ions and not sulfadiazine. Ionized silver from SSD in culture media was lower than that from silver nitrate; however, SSD, rather than silver nitrate, eradicated mature biofilms by bacterial killing. In SSD, sulfadiazine selectively bound to biofilms, and silver ions were then liberated. Consequently, the addition of an ion-chelator reduced the bactericidal effects of SSD on biofilms. These results indicate that SSD is an effective compound for the eradication of biofilms; thus, SSD should be used for the removal of biofilms formed on wounds.
ISSN:2076-2607