SORDELLI Daniel Oscar
congresos y reuniones científicas
Synthetic compounds as potential inhibitors of biofilm formation by methicillin-resistant and -sensitive Staphylococcus aureus.
LOMBARTE SERRAT A; DOTTO C; HRAST M; SOVA M; GOBEC S; SULIGOY LOZANO CM; SORDELLI DO; SASO L; GIACOMODONATO MN; BUZZOLA FR
Simposio; International Symposium on Staphylococcus and Staphylococcal Infections; 2016
ISSSI and Korean Society for Chemotherapy
Background: biofilms are involved in chronic persistent infections, such as bovine mastitis, osteomyelitis and foreign body-related infections. Biofilms may be responsible, in part, of late reactivation of staphylococcal chronic infections after the initial disease has been cured. The increasing prevalence of methicillin-resistant S. aureus (MRSA) and the emergence of vancomycin-resistant S. aureus have created major problems to the Public Health. Since antibiotics are becoming increasingly ineffective in the treatment of biofilm-associated infections, the search for new compounds with anti-biofilm properties are urgently need.Methods: this study investigates the inhibitory effect of four phenolic compounds (named F1-F4 for simplicity) prior-to and post-biofilm formation by methicillin-sensitive S. aureus (MSSA) and MRSA strains related to the USA300 and USA100 clones. To avoid the identification of strain-specific hits, the study was performed on isolates from milk of bovines with mastitis, isolates from human osteomyelitis and laboratory strains. Bacteria were treated with compounds before biofilm formation takes place (prior-to-exposure) and 24 h after biofilms were formed (post-exposure). The biofilm biomass was stained with crystal violet for spectrophotometric quantification. The inhibitory effect of compounds on biofilms was visualized by scanning electron microscopy.Results: the initial screening using the Newman strain showed the phenolic compounds as inactive (F1), moderately active (F2, F4) or highly active (F3). The prior-to-exposure evaluation revealed that F2 induced 89% to 39% biofilm inhibition showing higher activity on MSSA from bovines than those S. aureus isolates from humans. It is important to note that F3 (N-(3-cyano-4,5,6,7-tetrahydrobenzo [b] thiophen-2-yl)-3-hydroxybenzamide) presented a significant biofilm inhibitory effect by 77% to 23% in all but one strains under scrutiny. F4 decreased biofilm production by 23% only in the Newman strain. No compound affected the formation of biofilm by AR77, a MSSA strain of bovine origin.Conclusions: post-exposure of S. aureus to F3 produced an anti-biofilm effect in most strains analysed. It is likely that, in the presence of F3, certain bacterial cells are able to attach and form biofilms, but their maturation process is significantly hampered. This study highlights the potential of F3 as a successful agent that can act prior-to and post- biofilm development.