SORDELLI Daniel Oscar
congresos y reuniones científicas
Effect of phenolic compounds on Staphylococcus aureus biofilm development.
LOMBARTE SERRAT A; DOTTO C; HRAST M; SOVA L; GOBEC S; SULIGOY LOZANO CM; SORDELLI DO; SASO L; GIACOMODONATO MN; BUZZOLA FERNANDA R.
Conferencia; Conferencia bianual de la Society for General Microbiology (SAMiGe-Argentina).; 2015
Society for General Microbiology (SAMiGe-Argentina).
Staphylococcus aureus causes a wide range infectious diseases inhumans and animals. Biofilms have been linked to bovine mastitis since S. aureus biofilm-producer strains showed anincreased ability to attach to mammary mucosal surfaces and cause persistentinfections compared with non-biofilm forming strains. S. aureus biofilm formation partially depends uponthe production of polysaccharide intercellular adhesin (PIA), coded by the ica operon. Antibiotic therapy is becoming increasingly ineffective in thetreatment of biofilm-associated infections. Therefore, the search for newchemical compounds with anti-biofilm properties becomes necessary. The aim ofthis study was to investigate the inhibitory effect of four phenolic compounds(named F1-F4 for simplicity) prior-to and post- biofilm formation by S. aureus. To avoid the identification of strain-specific hits,the study was performed on five S.aureus isolatesfrom milk of bovines with mastitis and two laboratory reference (Newman andSA113) S. aureus strains. The isolates were selected fortheir ability to produce large amounts of biofilm by either ica-dependent or -independent mechanisms. Bacteria were treated withcompounds before biofilm formation takes place (prior-to-exposure) and 24 hafter biofilms were formed (post-exposure). The biofilm biomass was stainedwith crystal violet for spectrophotometric Congreso Argentino de MicrobiologíaGeneral SAMIGE - 2015 Página: 106 quantification. The initial screening in theNewman strain allowed to classify the phenolic compounds as inactive (F1), moderatelyactive (F2, F4) or highly active (F3). Only N-(3-cyano-4,5,6,7-tetrahydrobenzo [b] thiophen-2-yl)-3-hydroxybenzamide (F3)presented a moderate but significant dose-dependent effect on the inhibition ofbiofilm formed by the strains under study. The different phenolic compoundsshowed no bacteriostatic or bactericidal activity. The prior-to-exposureevaluation revealed that F2 induced 89%, 86% and 43% biofilm inhibition inAR99, RF122 and SA113 S. aureusstrains, respectively.F3 was able to inhibit by 77% to 23% the biofilm formation in all strains underscrutiny except AR77. F4 decreased biofilm production by 23% only in the Newmanstrain. No compound affected the AR77 biofilm formation. Results obtained bypost-exposure of phenolic compounds indicated that F3 showed an anti-biofilmeffect in most strains analyzed except V329 and RF122. Data obtained from F1experiments did not show any significant effect on biofilm inhibition orinactivation in any of the strains under study confirming its inactivity. It islikely that in the presence of F3, certain bacterial cells are able to attachand form biofilms, but their maturation process is significantly hampered. Thisstudy highlights the potential of F3 as a successful agent that can actprior-to and post- biofilm development.