Scientific Reports (Aug 2021)

Citral modulates virulence factors in methicillin-resistant Staphylococcus aureus

  • Hellen Braga Martins Oliveira,
  • Nathan das Neves Selis,
  • Beatriz Almeida Sampaio,
  • Manoel Neres Santos Júnior,
  • Suzi Pacheco de Carvalho,
  • Jéssica Bomfim de Almeida,
  • Palloma Porto Almeida,
  • Icaro Bonyek Santos da Silva,
  • Caline Novais Teixeira Oliveira,
  • Thamara Louisy Santos Brito,
  • Letícia de Oliveira da Silva,
  • Mariana Morais Teixeira,
  • Hanna Izadora Laís Novaes Coelho,
  • Camila Dutra Barbosa,
  • Yasmin Monara Ferreira de Sousa Andrade,
  • Rafaela de Souza Bittencourt,
  • Jully Chayra Santos Viana,
  • Guilherme Barreto Campos,
  • Jorge Timenetsky,
  • Ana Paula T. Uetanabaro,
  • Regiane Yatsuda,
  • Lucas Miranda Marques

DOI
https://doi.org/10.1038/s41598-021-95971-y
Journal volume & issue
Vol. 11, no. 1
pp. 1 – 11

Abstract

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Abstract Methicillin-resistant Staphylococcus aureus (MRSA) is responsible for high morbidity and mortality rates. Citral has been studied in the pharmaceutical industry and has shown antimicrobial activity. This study aimed to analyze the antimicrobial activity of citral in inhibiting biofilm formation and modulating virulence genes, with the ultimate goal of finding a strategy for treating infections caused by MRSA strains. Citral showed antimicrobial activity against MRSA isolates with minimum inhibitory concentration (MIC) values between 5 mg/mL (0.5%) and 40 mg/mL (4%), and minimum bactericidal concentration (MBC) values between 10 mg/mL (1%) and 40 mg/mL (4%). The sub-inhibitory dose was 2.5 mg/mL (0.25%). Citral, in an antibiogram, modulated synergistically, antagonistically, or indifferent to the different antibiotics tested. Prior to evaluating the antibiofilm effects of citral, we classified the bacteria according to their biofilm production capacity. Citral showed greater efficacy in the initial stage, and there was a significant reduction in biofilm formation compared to the mature biofilm. qPCR was used to assess the modulation of virulence factor genes, and icaA underexpression was observed in isolates 20 and 48. For icaD, seg, and sei, an increase was observed in the expression of ATCC 33,591. No significant differences were found for eta and etb. Citral could be used as a supplement to conventional antibiotics for MRSA infections.