Effects of growth in the presence of subinhibitory concentrations of dicloxacillin on Staphylococcus epidermidis and Staphylococcus haemolyticus biofilms.
نویسندگان
چکیده
Low concentrations of antibiotics can inhibit microbial adherence to medical device surfaces. However, little is known about the changes that occur in the physiology of bacteria within biofilms formed in the presence of subinhibitory (sub-MIC) concentrations of antibiotics. In this study, the densities and matrix compositions of biofilms formed by two coagulase-negative Staphylococcus species in the absence and in the presence of sub-MIC concentrations of dicloxacillin were evaluated. Biofilms formed in the presence of sub-MIC concentrations of dicloxacillin contained less biomass, and there were notable changes in the composition of the biofilm matrix. Changes in the spatial structure were also verified by confocal scanning laser microscopy, indicating that biofilms grown in the presence of sub-MIC concentrations of dicloxicilln had a lower cell density. Physiological alterations in the bacteria within biofilms grown in the presence of subinhibitory concentrations of the antibiotic were also evaluated. The results showed that there were differences in bacterial surface characteristics when cultures were grown in the presence of sub-MIC concentrations of dicloxacillin, including decreased hydrophobicity and decreased expression of the exopolysaccharide poly-N-acetylglucosamine. The elemental composition of the cell surface was also analyzed, and whereas in Staphylococcus epidermidis there were decreases in the oxygen and nitrogen contents, in Staphylococcus haemolyticus there were increases in these two parameters. Additionally, increases in resistance to several antibiotics were observed for the cells within biofilms formed in the presence of dicloxacillin.
منابع مشابه
The Effect of Biosurfactant of Saccharomyces Cerevisiae on Biofilms Produced by Staphylococcus Aureus, Epidermidis and Saprophyticus: A Laboratory Study
Background and Objectives: Biosurfactants are amphiphilic molecules produced by microorganisms that due to surfactant activity, have several applications in different industries such as cleaning, emulsification, foaming and dispersion. The aim of this study was to investigate the effect of biosurfactant extracted from saccharomycess cerevisiae on biofilm formation of staphylococcus aureus (PTC...
متن کاملبررسی اثـر نانـوذرات نقـره بر بیـوفیلمهای ناشی از استافیلوکوکوس اپیدرمیدیس
Background and Objective: Staphylococcus epidermidis produces extracellular polysaccharide which is known as a biofilm. Biofilm is highly effective in establishing of this bacterium infections and can be formed on medical devices that are used in the body. The purpose of this study was to evaluate the effects of silver colloidal nanoparticles on bacterial growth and biofilm form...
متن کاملComparative assessment of antibiotic susceptibility of coagulase-negative staphylococci in biofilm versus planktonic culture as assessed by bacterial enumeration or rapid XTT colorimetry.
OBJECTIVES To quantitatively compare the antibiotic susceptibility of biofilms formed by the coagulase-negative staphylococci (CoNS) Staphylococcus epidermidis and Staphylococcus haemolyticus with the susceptibility of planktonic cultures. METHODS Several CoNS strains were grown planktonically or as biofilms to determine the effect of the mode of growth on the level of susceptibility to antib...
متن کاملEffects of oregano, carvacrol and thymol on Staphylococcus aureus and Staphylococcus epidermidis biofilms.
The aim of this study was to evaluate the effect of oregano essential oil, carvacrol and thymol on biofilm-grown Staphylococcus aureus and Staphylococcus epidermidis strains, as well as the effects of the oils on biofilm formation. For most of the S. aureus (n=6) and S. epidermidis (n=6) strains tested, the biofilm inhibitory concentration (0.125-0.500 %, v/v, for oregano, and 0.031-0.125 %, v/...
متن کاملInvestigation of the effect of biosurfactant of Bacillus subtilis against Staphylococcus strains biofilms
Background: Biosurfactants are compounds that are produced by different microorganisms and have an emulsifying property. This study aimed to investigate extractive biosurfactant from bacillus subtilis (PTCC1720) against the biofilms of Staphylococcus aureus (PTCC 1112), Staphylococcus saprophyticus (PTCC 1440) and Staphylococcus epidermidis (PTCC 1435). Materials and Methods: This study was con...
متن کاملذخیره در منابع من
با ذخیره ی این منبع در منابع من، دسترسی به آن را برای استفاده های بعدی آسان تر کنید
برای دانلود متن کامل این مقاله و بیش از 32 میلیون مقاله دیگر ابتدا ثبت نام کنید
ثبت ناماگر عضو سایت هستید لطفا وارد حساب کاربری خود شوید
ورودعنوان ژورنال:
- Applied and environmental microbiology
دوره 71 12 شماره
صفحات -
تاریخ انتشار 2005