2(5H)-Furanone Derivatives as Inhibitors of Staphylococcal Biofilms

© 2016, Springer Science+Business Media New York.The opportunistic bacteria Staphylococcus aureus and Staphylococcus epidermidis often form rigid biofilms on wounds and artificial surfaces and thereby become extremely resistant to antimicrobials. Here, we report the effect of four novel 2(5H)-furanone derivatives on the cell growth and biofilm formation by these microorganisms. Using the differential fluorescence staining of viable and dead cells, we demonstrated that furanones increase the antibacterial efficacy of chloramphenicol against both biofilm-embedded S. aureus and S. epidermidis with F35 being the most efficient compound, probably by increasing the accessibility of cells against antimicrobials. Compounds F6, F8, and F83 inhibited the biofilm formation at concentrations of 2.5–10 μg/ml, although exhibiting high cytotoxicity for human skin fibroblasts with CC50 of 0.5–1.1 μg/ml. F35 demonstrated minimal biofilm inhibition concentration of 10 μg/ml, while its cytotoxicity was ten times lower than that of the other compounds (CC50 13.1 μg/ml), suggesting its chemotype seems a promising starting point for the development of new antibiofilm agents

Thio derivatives of 2(5H)-furanone as inhibitors against Bacillus subtilis biofilms

© 2015 Park-media, Ltd. Gram-positive bacteria cause a wide spectrum of infectious diseases, including nosocomial infections. While in the biofilm, bacteria exhibit increased resistance to antibiotics and the human immune system, causing difficulties in treatment. Thus, the development of biofilm formation inhibitors is a great challenge in pharmacology. The gram-positive bacterium Bacillus subtilis is widely used as a model organism for studying biofilm formation. Here, we report on the effect of new synthesized 2(5H)-furanones on the biofilm formation by B.subtilis cells. Among 57 compounds tested, sulfur-containing derivatives of 2(5H)-furanone (F12, F15, and F94) repressed biofilm formation at a concentration of 10 μg/ml. Derivatives F12 and F94 were found to inhibit the biosynthesis of GFP from the promoter of the eps operon encoding genes of the biofilm exopolysaccharide synthesis (EPS). Using the differential fluorescence staining of alive/dead cells, we demonstrated an increased bacterial sensitivity to antibiotics (kanamycin and chloramphenicol) in the presence of F12, F15, and F94, with F12 being the most efficient one. The derivative F15 was capable of disrupting an already formed biofilm and thereby increasing the efficiency of antibiotics

Targeting microbial biofilms using Ficin, a nonspecific plant protease

© The Author(s) 2017.Biofilms, the communities of surface-attached bacteria embedded into extracellular matrix, are ubiquitous microbial consortia securing the effective resistance of constituent cells to environmental impacts and host immune responses. Biofilm-embedded bacteria are generally inaccessible for antimicrobials, therefore the disruption of biofilm matrix is the potent approach to eradicate microbial biofilms. We demonstrate here the destruction of Staphylococcus aureus and Staphylococcus epidermidis biofilms with Ficin, a nonspecific plant protease. The biofilm thickness decreased two-fold after 24 hours treatment with Ficin at 10 μg/ml and six-fold at 1000 μg/ml concentration. We confirmed the successful destruction of biofilm structures and the significant decrease of non-specific bacterial adhesion to the surfaces after Ficin treatment using confocal laser scanning and atomic force microscopy. Importantly, Ficin treatment enhanced the effects of antibiotics on biofilms-embedded cells via disruption of biofilm matrices. Pre-treatment with Ficin (1000 μg/ml) considerably reduced the concentrations of ciprofloxacin and bezalkonium chloride required to suppress the viable Staphylococci by 3 orders of magnitude. We also demonstrated that Ficin is not cytotoxic towards human breast adenocarcinoma cells (MCF7) and dog adipose derived stem cells. Overall, Ficin is a potent tool for staphylococcal biofilm treatment and fabrication of novel antimicrobial therapeutics for medical and veterinary applications

Inhibition of biofilm formation in Bacillus subtilis by new halogenated furanones

© 2015 Japan Antibiotics Research Association All rights reserved. Gram-positive bacteria can cause various infections including hospital-acquired infections. While in the biofilm, the resistance of bacteria to both antibiotics and the human immune system is increased causing difficulties in the treatment. Bacillus subtilis, a non-pathogenic Gram-positive bacterium, is widely used as a model organism for studying biofilm formation. Here we investigated the effect of novel synthesized chloro- and bromo-containing 2(5H)-furanones on biofilm formation by B. subtilis. Mucobromic acid (3,4-dibromo-5-hydroxy-2(5H)-furanone) and the two derivatives of mucochloric acid (3,4-dichloro-5-hydroxy-2(5H)-furanone) - F8 and F12 - were found to inhibit the growth and to efficiently prevent biofilm formation by B. subtilis. Along with the low production of polysaccharide matrix and repression of the eps operon, strong repression of biofilm-related yqxM also occurred in the presence of furanones. Therefore, our data confirm that furanones affect significantly the regulatory pathway(s) leading to biofilm formation. We propose that the global regulator, Spo0A, is one of the potential putative cellular targets for these compounds

New derivatives of pyridoxine exhibit high antibacterial activity against biofilm-embedded staphylococcus cells

© 2015 Airat R. Kayumov et al. Opportunistic bacteria Staphylococcus aureus and Staphylococcus epidermidis often form rigid biofilms on tissues and inorganic surfaces. In the biofilm bacterial cells are embedded in a self-produced polysaccharide matrix and thereby are inaccessible to biocides, antibiotics, or host immune system. Here we show the antibacterial activity of newly synthesized cationic biocides, the quaternary ammonium, and bisphosphonium salts of pyridoxine (vitamin B6) against biofilm-embedded Staphylococci. The derivatives of 6-hydroxymethylpyridoxine were ineffective against biofilm-embedded S. aureus and S. epidermidis at concentrations up to 64 g/mL, although all compounds tested exhibited low MICs (2 g/mL) against planktonic cells. In contrast, the quaternary ammonium salt of pyridoxine (N,N-dimethyl-N-((2,2,8-trimethyl-4H-[1,3]dioxino[4,5-c]pyridin-5-yl)methyl)octadecan-1-aminium chloride (3)) demonstrated high biocidal activity against both planktonic and biofilm-embedded bacteria. Thus, the complete death of biofilm-embedded S. aureus and S. epidermidis cells was obtained at concentrations of 64 and 16 g/mL, respectively. We suggest that the quaternary ammonium salts of pyridoxine are perspective to design new synthetic antibiotics and disinfectants for external application against biofilm-embedded cells

Trypsin immobilization on the Chitosan matrix of various molecular weights

© 2017, Folium Ltd. All rights reserved. The trypsin immobilization technique on the chitosan matrix of various molecular weights allowing to reach extent of enzyme sorption about 65% is developed. Absence gene and cytotoxicity of this complexes is shown. It serves as argument in favor of safety of their application

Antimicrobial effects of sulfonyl derivative of 2(5H)-furanone against planktonic and biofilm associated methicillin-resistant and -susceptible Staphylococcus aureus

© 2017 Sharafutdinov, Trizna, Baidamshina, Ryzhikova, Sibgatullina, Khabibrakhmanova, Latypova, Kurbangalieva,Rozhina, Klinger-Strobel, Fakhrullin, Pletz, Bo gachev, Kayumov and Makarewicz. The gram-positive opportunistic bacterium Staphylococcus aureus is one of the most common causatives of a variety of diseases including skin and skin structure infection or nosocomial catheter-associated infections. The biofilm formation that is an important virulence factor of this microorganism renders the antibiotic therapy ineffective, because biofilm-embedded bacteria exhibit strongly increased tolerance to antimicrobials. Here, we describe a novel 3-chloro-5(S)-[(1R,2S,5R)-2-isopropyl-5-methylcyclohexyloxy]-4-[4-methylphenylsulfonyl] -2(5H)-furanone (F105), possessing a sulfonyl group and l-menthol moiety. Minimal inhibitory and bactericidal concentration values (MIC and MBC) of F105 were 10 and 40 mg/L, respectively, suggesting F105 biocidal properties. F105 exhibits pronounced activity against biofilm-embedded S. aureus and increases the efficacy of aminoglycosides (amikacin, gentamicin, and kanamycin) and benzalkonium chloride with fractional inhibitory concentration index values of 0.33-0.44 and 0.29, respectively, suggesting an alternative external treatment option, e.g., for wound infections. Moreover, low concentrations (0.5-1.3 mg/L) of F105 reduced the MICs of these antimicrobials twofold. By using confocal laser scanning microscopy and CFU counting, we show explicitly that F105 also restores the antimicrobial activity of gentamicin and ampicillin against S. aureus biofilms by several orders of magnitude. Biofilm structures were not destroyed but sterilized, with embedded cells being almost completely killed at twofold MBC. While F105 is quite toxic (CC 50 /MBC ratio 0.2), our data suggest that the F105 chemotype might be a promising starting point for the development of complex topical agents for combined anti-staphylococcal biofilm-therapies restoring the efficacy of some antibiotics against difficult to treat S. aureus biofilm

Genome Instability and Bleomicin Sensitivity Test

Procjena individualne osjetljivosti na mutagene često je dio istraživanja u epidemiološkim studijama koje prate pojavnost zloćudnih bolesti u populacijama. Posljedica djelovanja mutagena u genomu izloženih osoba jest nastanak određene, manje ili veće, količine oštećenja, uvjetovane individualnim razlikama u osjetljivosti. Viša razina takve genomske nestabilnosti znači opasnost (rizik) od razvoja zloćudnih bolesti. Interindividualne razlike u odgovoru na mutagene obično se povezuju i s promijenjenom (većinom smanjenom) sposobnosti (kapacitetom) za popravak DNA. Citogenetičke studije su pokazale da je genom tumorskih stanica nestabilniji od normalnih, a time i skloniji akumuliranju oštećenja, bilo da je nestabilnost uzrokovana nasljeđem, izloženošću ili kombinacijom tih dvaju učinaka. U oboljelih ispitanika utvrđena je povećana učestalost kromatidnih i kromosomskih aberacija naspram normalne populacije te sklonost razvoju određenih vrsta neoplazija. U praćenju povezanosti promijenjenog odgovora i pojavnosti tumora služe nam različiti biomarkeri. Kao indirektni pokazatelji uspješnosti popravka DNA često se rabe testovi osjetljivosti na mutagene u kulturama limfocita periferne krvi. Jedan od takvih testova je i bleomicinski test. Radiomimetik i citostatik, a po strukturi glikopeptid, bleomicin se u stanici prevodi u aktivni oblik sposoban cijepati molekulu DNA što uzrokuje brojne jednolančane i dvolančane lomove. Kao jednostavna i jeftina metoda, zasniva se na utvrđivanju ukupnog broja jednolančanih lomova u kromosomima limfocita uzgajanih u staničnoj kulturi koji su u uvjetima in vitro tijekom kasne G2-faze staničnog ciklusa bili izloženi bleomicinu. Ovaj revijalni rad daje pregled utjecaja raznih faktora na rezultate samog testa i pokazuje njegovu široku primjenu u proučavanju genomske nestabilnosti koju najčešće uzrokuje kombinacija raznih faktora.Estimation of individual susceptibility to mutagens is often a part of epidemiological studies monitoring the appearance of malignant disease in different populations. Genome exposure to mutagens can lead to DNA damage. The rate of damage depends on individual differences in response, which are usually associated with differences in DNA repair capacity. Cytogenetic studies have shown that the genome of tumour cells is less stable than normal cells and therefore accumulates more damage. Tumour patients show a higher frequency of chromatid and chromosomal aberrations and a predisposition to certain types of tumours. One of the common biomarkers used in monitoring tumour appearance and changed response to DNA damage is the bleomycin test. In its active form, bleomycin (glycopeptid) is a radiomimetic cytostatic that can damage the DNA molecule and cause multiple single and double strands. The bleomycin test is simple and inexpensive, and is based on scoring chromatid breaks in lymphocytes in vitro exposed to bleomycin during the late G2 phase of the cell cycle. This review looks into different factors that may affect test results and discusses its wide implementation in studies of genome instability usually caused by a combination of factors

Degrading of the Pseudomonas Aeruginosa Biofilm by Extracellular Levanase SacC from Bacillus subtilis

© 2018, Springer Science+Business Media, LLC, part of Springer Nature. Pseudomonas aeruginosa is an opportunistic pathogenic bacterium causing variety of biofilm-related infections in patients with burns, lung cancer, chronic obstructive pulmonary disease, and cystic fibrosis. Here, we show that extracellular levanase SacC from Bacillus subtilis disrupts the matrix biofilm of P. aeruginosa and this way increasing the efficacy of antibiotics against biofilm-embedded bacteria. In particular, the biofilm thickness decreased twofold after 2 h of treatment with levanase at 1 mg/ml, while 5 mg/ml of cellulase was required for the same effect. Next, in the presence of SacC, the efficacy of ciprofloxacin against biofilm-embedded P. aeruginosa increased fourfold. While the efficacy of amikacin in the presence of SacC increased fourfold against detached cell clumps, it remained unchanged against biofilm-embedded cells. These data suggest that extracellular levanase from B. subtilis could appear an alternative to other glycoside hydrolases reported to be active against biofilms of P. aeruginosa agent for external wound treatment to suppress biofilm formation and reduce reinfection risks

Degrading of the Pseudomonas Aeruginosa Biofilm by Extracellular Levanase SacC from Bacillus subtilis

© 2018, Springer Science+Business Media, LLC, part of Springer Nature. Pseudomonas aeruginosa is an opportunistic pathogenic bacterium causing variety of biofilm-related infections in patients with burns, lung cancer, chronic obstructive pulmonary disease, and cystic fibrosis. Here, we show that extracellular levanase SacC from Bacillus subtilis disrupts the matrix biofilm of P. aeruginosa and this way increasing the efficacy of antibiotics against biofilm-embedded bacteria. In particular, the biofilm thickness decreased twofold after 2 h of treatment with levanase at 1 mg/ml, while 5 mg/ml of cellulase was required for the same effect. Next, in the presence of SacC, the efficacy of ciprofloxacin against biofilm-embedded P. aeruginosa increased fourfold. While the efficacy of amikacin in the presence of SacC increased fourfold against detached cell clumps, it remained unchanged against biofilm-embedded cells. These data suggest that extracellular levanase from B. subtilis could appear an alternative to other glycoside hydrolases reported to be active against biofilms of P. aeruginosa agent for external wound treatment to suppress biofilm formation and reduce reinfection risks