Antibacterial activity of a Tribolium castaneum defensin in an in vitro infection model of Streptococcus pneumoniae. Issue 1 (1st January 2019)

• Record Type: Journal Article
• Authors: Lindhauer, Nora S.; Bertrams, Wilhelm; Pöppel, Anne; Herkt, Christina E.; Wesener, Andre; Hoffmann, Kerstin; Greene, Brandon; Van Der Linden, Mark; Vilcinskas, Andreas; Seidel, Kerstin; Schmeck, Bernd
• Is Part Of: Virulence. Volume 10:Issue 1(2019)
• Page Start: 902
• Page End: 909
• Publication Date: 2019-01-01
• Subjects: Antimicrobial peptides -- Streptococcus pneumoniae -- macrophages -- inflammation -- insect -- antibiotic resistance -- defensin; Virulence (Microbiology) -- Periodicals; Bacterial diseases -- Periodicals; Molecular microbiology -- Periodicals; 579.05
• DOI: 10.1080/21505594.2019.1685150
• Languages: English
• ISSNs: 2150-5608

Abstract

ABSTRACT: Streptococcus pneumoniae ( S. pneumoniae ) is the most common bacterial cause of community-acquired pneumonia. Increasing rates of antibiotic-resistant S. pneumoniae strains impair therapy and necessitate alternative treatment options. In this study, we analysed insect-derived antimicrobial peptides (AMPs) for antibacterial effects on S. pneumoniae in a human in vitro infection model. AMP effects on bacterial growth were examined by colony forming unit (CFU)-assays, and growth curve measurements. Furthermore, cytotoxicity to primary human macrophages was detected by measuring lactate-dehydrogenase release to the supernatant. One AMP (Defensin 1) was tested in a model of primary human monocyte-derived macrophages infected with S. pneumoniae strain D39 and a multi-resistant clinical isolate. Inflammatory reactions were characterised by qPCR and multiplex-ELISA. In total, the antibacterial effects of 23 AMPs were characterized. Only Tribolium castaneum Defensin 1 showed significant antibacterial effects against S. pneumoniae strain D39 and a multi-resistant clinical isolate. During in vitro infection of primary human macrophages with S. pneumoniae D39, Defensin 1 displayed strong antibacterial effects, and consequently reduced bacteria-induced cytokine expression and release. In summary, Tribolium castaneum Defensin 1 showed profound antibacterial effectivity against Streptococcus pneumoniae D39 and a multi-resistant clinical isolate without unwanted cytotoxic or inflammatory side effects on human blood-derived macrophages.