Autor(es):
Cleto, S. 
; Simões, M. ; Matos, S. ; Vieira, M. J.
Data: 2008
Identificador Persistente: http://hdl.handle.net/1822/8541
Origem: RepositóriUM - Universidade do Minho
Detalhes do Documento
Serratia plymuthica dairy industry isolates and their antimicrobial metabolites...
Descrição
Background and aims: Phenotypical differences from interstrain variability is a known phenomenon, assessed in this study for V4 and Y S. plymuthica isolates, particularly at antimicrobial metabolites production and effect on pathogens biofilms. Methods: Isolates were biochemically characterized, specific growth rates in Tryptic Soy/Skim Milk Broth determined, and the antimicrobial activity of cell-free spent media tested on Staphylococcus aureus, Staphylococcus epidermidis, Pseudomonas aeruginosa, Bacillus cereus and Escherichia coli lawns. Their biofilm removal capacity was assessed on 24h pathogens biofilms, through 30min treatments, and biofilm formation impairment ability by 10min substratum pre-conditioning. Results: These siderophores and quorum-sensing inhibitors releasers isolates showed different protease expression and growth rates in both media. Droplets of isolates cell-free spent TSB presented positive inhibitory capacity. V4-SMB biofilms had equal mass and specific respiratory activity values, while low mass Y biofilms were extremely active. Its biofilms in TSB showed the opposite, being V4 biofilms particularly metabolically active and thicker. All cell-free SMB/TSB supernatants pre-conditioning led to a steep reduction of the respiratory activity of S. aureus, E. coli and S. epidermidis biofilms later formed, though increasing their mass. Biofilms treatment with any supernatant similarly decreased their mass. L. monocytogenes, was particularly affect by all, S.aureus by TSB/SMB V4-spent, and S. epidermidis by SMB V4-spent. Conclusions: S. plymuthica isolates registered different biofilm formation ability and cell-free spent TSB/SMB antimicrobial activity. An understanding of mechanisms underlying antimicrobials actionmode in single/mixed Gram positive/negative species biofilms is sought.
Background and aims: Phenotypical differences from interstrain variability is a known phenomenon, assessed in this study for V4 and Y S. plymuthica isolates, particularly at antimicrobial metabolites production and effect on pathogens biofilms. Methods: Isolates were biochemically characterized, specific growth rates in Tryptic Soy/Skim Milk Broth determined, and the antimicrobial activity of cell-free spent media tested on Staphylococcus aureus, Staphylococcus epidermidis, Pseudomonas aeruginosa, Bacillus cereus and Escherichia coli lawns. Their biofilm removal capacity was assessed on 24h pathogens biofilms, through 30min treatments, and biofilm formation impairment ability by 10min substratum pre-conditioning. Results: These siderophores and quorum-sensing inhibitors releasers isolates showed different protease expression and growth rates in both media. Droplets of isolates cell-free spent TSB presented positive inhibitory capacity. V4-SMB biofilms had equal mass and specific respiratory activity values, while low mass Y biofilms were extremely active. Its biofilms in TSB showed the opposite, being V4 biofilms particularly metabolically active and thicker. All cell-free SMB/TSB supernatants pre-conditioning led to a steep reduction of the respiratory activity of S. aureus, E. coli and S. epidermidis biofilms later formed, though increasing their mass. Biofilms treatment with any supernatant similarly decreased their mass. L. monocytogenes, was particularly affect by all, S.aureus by TSB/SMB V4-spent, and S. epidermidis by SMB V4-spent. Conclusions: S. plymuthica isolates registered different biofilm formation ability and cell-free spent TSB/SMB antimicrobial activity. An understanding of mechanisms underlying antimicrobials actionmode in single/mixed Gram positive/negative species biofilms is sought.
Tipo de Documento
Documento de conferência
Idioma Inglês
Idioma Inglês
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