Linezolid and vancomycin decrease the therapeutic effect of methylene blue-photodynamic therapy in a mouse model of MRSA bacterial arthritis

Masamitsu Tanaka, Pawel Mroz, Tianhong Dai, Liyi Huang, Yuji Morimoto, Manabu Kinoshita, Yasuo Yoshihara, Nariyoshi Shinomiya, Shuhji Seki, Koichi Nemoto, Michael R. Hamblin

Research output: Contribution to journalArticlepeer-review

11 Scopus citations

Abstract

We previously reported that photodynamic therapy (PDT) using intra-articular methylene blue (MB) could be used to treat arthritis in mice caused by bioluminescent methicillin-resistant Staphylococcus aureus (MRSA) either in a therapeutic or in a preventative mode. PDT accumulated neutrophils into the mouse knee via activation of chemoattractants such as inflammatory cytokines or chemokines. In this study, we asked whether PDT combined with antibiotics used for MRSA could provide added benefit in controlling the infection. We compared MB-PDT alone, systemic administration of either linezolid (LZD) alone or vancomycin (VCM) alone or the combination of PDT with either LZD or VCM. Real-time noninvasive imaging was used to serially follow the progress of the infection. PDT alone was the most effective, whereas LZD alone was ineffective and VCM alone showed some benefit. Surprisingly the addition of LZD or VCM reduced the therapeutic effect of PDT alone (P < 0.05). Considering that PDT in this mouse model stimulates neutrophils to be antibacterial rather than actively killing the bacteria, we propose that LZD and VCM might inhibit the activation of inflammatory cytokines without eradicating the bacteria, and thereby reduce the therapeutic effect of PDT.

Original languageEnglish (US)
Pages (from-to)679-682
Number of pages4
JournalPhotochemistry and Photobiology
Volume89
Issue number3
DOIs
StatePublished - May 2013

Fingerprint

Dive into the research topics of 'Linezolid and vancomycin decrease the therapeutic effect of methylene blue-photodynamic therapy in a mouse model of MRSA bacterial arthritis'. Together they form a unique fingerprint.

Cite this