title: Cinnamaldehyde InhibitsStaphylococcus aureusVirulence Factors and Protects against Infection in aGalleria mellonellaModel.
abstract: Bacterial resistance to the available marketed drugs has prompted the search of novel therapies; especially in regards of anti-virulence strategies that aim to make bacteria less pathogenic and/or decrease their probability to become resistant to therapy. Cinnamaldehyde is widely known for its antibacterial properties through mechanisms that include the interaction of this compound with bacterial cell walls. However, only a handful of studies have addressed its effects on bacterial virulence, especially when tested at sub-inhibitory concentrations. Herein, we show for the first time that cinnamaldehyde is bactericidal againstStaphylococcus aureusandEnterococcus faecalismultidrug resistant strains and does not promote bacterial tolerance. Cinnamaldehyde actions were stronger onS. aureusas it was able to inhibit its hemolytic activity on human erythrocytes and reduce its adherence to latex. Furthermore, cinnamaldehyde enhanced the serum-dependent lysis ofS. aureus.In vivotesting of cinnamaldehyde inGalleria mellonellalarvae infected withS. aureus, showed this compound improves larvae survival whilst diminishing bacterial load in their hemolymph. We suggest that cinnamaldehyde may represent an alternative therapy to controlS. aureus-induced bacterial infections as it presents the ability to reduce bacterial virulence/survival without promoting an adaptive phenotype.
authors.affiliation: Programa de Pós-graduação, Universidade CEUMA São Luís, Brazil.
authors.forename: Thiago A F
authors.initials: TA
authors.lastname: Ferro
authors.affiliation: Programa de Pós-graduação, Universidade CEUMA São Luís, Brazil.
authors.forename: Jéssica M M
authors.initials: JM
authors.lastname: Araújo
authors.affiliation: Programa de Pós-graduação, Universidade CEUMA São Luís, Brazil.
authors.forename: Bruna L
authors.initials: BL
authors.lastname: Dos Santos Pinto
authors.affiliation: Programa de Pós-graduação, Universidade CEUMA São Luís, Brazil.
authors.forename: Jéssica S
authors.initials: JS
authors.lastname: Dos Santos
authors.affiliation: Programa de Pós-graduação, Universidade CEUMA São Luís, Brazil.
authors.forename: Eliene B
authors.initials: EB
authors.lastname: Souza
authors.affiliation: Programa de Pós-graduação, Universidade CEUMA São Luís, Brazil.
authors.forename: Bruna L R
authors.initials: BL
authors.lastname: da Silva
authors.affiliation: Programa de Pós-graduação, Universidade CEUMA São Luís, Brazil.
authors.forename: Valderlane L P
authors.initials: VL
authors.lastname: Colares
authors.affiliation: Programa de Pós-graduação, Universidade CEUMA São Luís, Brazil.
authors.forename: Tânia M G
authors.initials: TM
authors.lastname: Novais
authors.affiliation: Universidade Federal de Pernambuco Pernambuco, Brazil.
authors.forename: Clovis M B
authors.initials: CM
authors.lastname: Filho
authors.affiliation: Statens Serum Institut Copenhagen, Denmark.
authors.forename: Carsten
authors.initials: C
authors.lastname: Struve
authors.affiliation: Centro de Inovação e Estudos Pré-clínicos Florianópolis, Brazil.
authors.forename: João B
authors.initials: JB
authors.lastname: Calixto
authors.affiliation: Programa de Pós-graduação, Universidade CEUMASão Luís, Brazil; Universidade Federal do MaranhãoSão Luís, Brazil.
authors.forename: Valério
authors.initials: V
authors.lastname: Monteiro-Neto
authors.affiliation: Programa de Pós-graduação, Universidade CEUMA São Luís, Brazil.
authors.forename: Luís C N
authors.initials: LC
authors.lastname: da Silva
authors.affiliation: Programa de Pós-graduação, Universidade CEUMA São Luís, Brazil.
authors.forename: Elizabeth S
authors.initials: ES
authors.lastname: Fernandes
keywords: S. aureus; bacterial virulence; cinnamaldehyde; essential oil; infection