Comparative proteomic analysis of Listeria monocytogenes ATCC 7644 exposed to a sublethal concentration of nisin.
Listeria monocytogenes infections have been frequently reported in many food poisoning outbreaks around the world. In this work, the protein repertoires of L. monocytogenes ATCC 7644 cells treated or not with a 10(-3)mg/mL nisin sublethal concentration, established by antimicrobial susceptibility tests, were analyzed by LC-MS/MS. Overall, 179 proteins were identified, 9 of them more abundant in nisin-treated samples, and 4 more abundant in non-treated control samples. In nisin treated cells, proteins associated to oxidative stress response showed higher abundance. Also, the higher abundance of an enzyme related to the production of cell membrane lipids upon nisin exposure is suggestive of both a failure in conventional cell division mechanism and the activation of an alternative L-form mediated division mechanism. Finally, flagellar and motility proteins' overexpression upon nisin exposure is indicative of increased bacterial motility in response to the bacteriocin. Taken together, these results provide new insights on nisin effects on L. monocytogenes cells and on how this bacterium may overcome a bacteriocin-containing environment.


CONCLUSIONS
The antimicrobial mechanism of nisin on target bacterial cells has been extensively studied since discovery of this bacteriocin. The nisin pore-forming mechanism is mediated by its binding to the pyrophosphate portion of membrane lipid II [1], but some evidences point out to alternative mechanisms. Results from assays with mutacin 1140 hybrids [2] showed that the portion of nisin that is not involved with lipid II binding could damage the bacterial cell, independently of pore formation [3,4]. Moreover, there are insufficient data to explain how nisin affects the bacterial survival. In this scenario, proteomics is an interesting approach, as a comparison between treated and untreated cells may provide insights of both antimicrobial mechanisms of action and bacterial response mechanisms [5].
Programa de Pós-Graduação em Biologia Celular e Molecular, Centro de Biotecnologia, Universidade Federal do Rio Grande do Sul (UFRGS), Porto Alegre, Brazil.
Kendi Nishino
KN
Miyamoto
Laboratório de Genômica Estrutura e Funcional, Centro de Biotecnologia, UFRGS, Porto Alegre, Brazil; Departamento de Biologia Molecular e Biotecnologia, Instituto de Biociências, UFRGS, Porto Alegre, Brazil.
Karina Mariante
KM
Monteiro
Laboratório de Genômica Estrutura e Funcional, Centro de Biotecnologia, UFRGS, Porto Alegre, Brazil.
Karin
K
da Silva Caumo
Programa de Pós-Graduação em Biologia Celular e Molecular, Centro de Biotecnologia, Universidade Federal do Rio Grande do Sul (UFRGS), Porto Alegre, Brazil; Laboratório de Genômica Estrutura e Funcional, Centro de Biotecnologia, UFRGS, Porto Alegre, Brazil.
Karina Rodrigues
KR
Lorenzatto
Programa de Pós-Graduação em Biologia Celular e Molecular, Centro de Biotecnologia, Universidade Federal do Rio Grande do Sul (UFRGS), Porto Alegre, Brazil; Laboratório de Genômica Estrutura e Funcional, Centro de Biotecnologia, UFRGS, Porto Alegre, Brazil; Departamento de Biologia Molecular e Biotecnologia, Instituto de Biociências, UFRGS, Porto Alegre, Brazil. Electronic address: henrique@cbiot.ufrgs.br.
Henrique Bunselmeyer
HB
Ferreira
Programa de Pós-Graduação em Biologia Celular e Molecular, Centro de Biotecnologia, Universidade Federal do Rio Grande do Sul (UFRGS), Porto Alegre, Brazil; Laboratório de Bioquímica e Microbiologia Aplicada, Instituto de Ciência e Tecnologia de Alimentos, UFRGS, Porto Alegre, Brazil. Electronic address: abrand@ufrgs.br.
Adriano
A
Brandelli
D000900:Anti-Bacterial Agents / Q000494:pharmacology*; D001426:Bacterial Proteins / Q000096:biosynthesis*; D004305:Dose-Response Relationship, Drug; D008089:Listeria monocytogenes / Q000378:metabolism*; D009561:Nisin / Q000494:pharmacology*; D040901:Proteomics
D000900:Anti-Bacterial Agents; D001426:Bacterial Proteins; D009561:Nisin
Bacteriocin; Listeria monocytogenes; Mass spectrometry; Mechanisms of action; Nisin