Browsing by Author "Aybey, Aynur"
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Publication Antibacterial and antibiofilm properties of phlomis and stachys species(Bangladesh Botanical Soc, 2020-06-01) Aybey, Aynur; Aybey, Aynur; Bursa Uludağ Üniversitesi/Fen-Edebiyat Fakültesi/Biyoloji Bölümü; 0000-0003-2743-9745; CJN-1872-2022The ethyl acetate and methanol extracts of Phlomis pungens var. pungens, P. nissolii, P. armeniaca and Stachys byzantina, S. cretica L. subsp. mersiaea and S. cretica L. subsp. Smyrnaea were evaluated for their antibacterial and antibiofilm activities. Five bacterial species were used are Bacillus subtilis, Pseudomonas aeruginosa, Shigella sonnei, Salmonella typhimurium and Yersinia enterocolitica. The ethyl acetate and methanol extracts of plant species showed good antibacterial activity against all bacterial strains. More significantly, ethylacetate and methanol extracts of all Phlomis species were found to be more effective on degredation of mature biofilm against all used bacterial strains than extracts of Stachys species. The findings of the present study highlight the promising role of Phlomis and Stachys extracts as new lead structures in the search for novel antibacterial and antibiofilm agents.Item Bir antimikrobiyal ajan olarak paraoksonaz1 (laktonaz) enziminin pseudomonas aerugınosa quorum sensıng ilişkili davranışlarına etkisinin incelenmesi(Uludağ Üniversitesi, 2014) Aybey, Aynur; Demirkan, Elif; Uludağ Üniversitesi/Fen Bilimleri Enstitüsü/Biyoloji Anabilim Dalı.Pseudomonas aeruginosa'da birçok virulans faktörü üretiminin düzenlenmesinde Quorum sensing (QS)'in rolü gösterilmiştir. P. aeruginosa'da yüksek antibiyotik direnci yeni tedavi seçenekleri arayışına yol açmış ve QS sisteminin inhibisyonu mercek altına alınmıştır. Bakterinin virulansında azalmaya yol açacak QS inhibitörü ajanların bulunması ile P. aeruginosa infeksiyonları tedavisinde yeni yaklaşımlar geliştirilebilir. Bu amaçla çalışmada, P. aeruginosa'da QS sinyal moleküllerini laktonaz aktivitesi ile hidroliz eden insan serum paraoksonaz 1 (hPON1) enzimi kullanılmıştır. hPON1 enzimi, amonyum sülfat çöktürmesi ve hidrofobik etkileşim kromatografisi (Sepharose 4B-L-tirozin-1-Naftilamin) yöntemleri kullanılarak saflaştırılmıştır. Saf enzim, SDS-poliakrilamid jel elektroforezi ile 43 kDa olan tek bir bant olarak saptanmıştır. 3 adet P. aeruginosa suşları büyüme eğrisi için değerlendirilmiş ve durağan faz süreleri tespit edilmiştir. Durağan fazdaki bakteri örnekleri hPON1 enziminin artan konsantrasyonu katılarak (0,1-10 mg/ml) üretilmiştir. Bu suşlar arasında, P. aeruginosa ATCC35032 üremesinin 2,5 mg/ml konsantrasyondan itibaren azaldığı bulunmuştur ve çalışmalara bu suş ile devam edilmiştir. Çalışmada, her bir davranış için farklı konsantrasyonlarda kullanılan hPON1 enziminin bakterinin virulans faktörlerini, hareketliliğini ve biyofilm oluşumunu azalttığı bulunmuştur. Ancak, hPON1 enzimi (0,1-10 mg/ml) virulans faktörlerinden elastaz ve LasA proteaz üzerine azaltıcı yönde bir etki göstermemiş, alkali proteaza karşı ise 0,1 mg/ml gibi düşük konsantrasyonda azaltıcı etkisi saptanmıştır. 0,3-5 mg/ml konsantrasyonları arasında piyosiyanin ve ramnolipid üretimlerinin 1,25 mg/ml'de önemli ölçüde azalmıştır. hPON1 enzimi (0,1-10 mg/ml), biyofilm oluşumu ve olgun biyofilmleri de 1 mg/ml'de %50 oranında azaltmıştır. Olgun biyofilmlerin EPS bileşenini yıkıma uğratmıştır. Enzimin 0,003-30 mg/ml konsantrasyonları arasında kayma, yüzme ve titreme hareketlerine azaltıcı etkisi düşük konsantrasyon olan 0,3 mg/ml'de oldukça yüksek olmuştur.Item Inhibition of quorum sensing-controlled virulence factors in Pseudomonas aeruginosa by human serum paraoxonase(Microbiology, 2015-12-07) Aybey, Aynur; Demirkan, Elif; Uludağ Üniversitesi/Fen-Edebiyat Fakültesi/Biyoloji Bölümü.; ABI-4472-2020; 55353798200; 23469245200The role of quorum sensing (QS) in the regulation of virulence factor production in Pseudomonas aeruginosa is well established. Increased antibiotic resistance in this bacterium has led to the search for new treatment options, and inhibition of the QS system has been explored for potential therapeutic benefits. If the use of QS inhibitory agents were to lead to a reduction in bacterial virulence, new approaches in the treatment of P. aeruginosa infections could be further developed. Accordingly, we examined whether human serum paraoxonase 1 (hPON1), which uses lactonase activity to hydrolyse N-acyl homoserine lactones, could cleave P. aeruginosa-derived signalling molecules. hPON1 was purified using ammonium sulfate precipitation and hydrophobic interaction chromatography (Sepharose 4B-L-tyrosine-1-naphthylamine). Different concentrations of hPON1 were found to reduce various virulence factors including pyocyanin, rhamnolipid, elastase, staphylolytic LasA protease and alkaline protease. Although treatment with 0.1-10 mg hPON1 ml(-1) did not show a highly inhibitory effect on elastase and staphylolytic LasA protease production, it resulted in good inhibitory effects on alkaline protease production at concentrations as low as 0.1 mg ml(-1). hPON1 also reduced the production of pyocyanin and rhamnolipid at a concentration of 1.25 mg ml(-1) (within a range of 0.312-5 mg ml(-1)). In addition, rhamnolipid, an effective biosurfactant reported to stimulate the biodegradation of hydrocarbons, was able to degrade oil only in the absence of hPON1.Publication Signal interference effect of human paraoxonase 1 using as substrates N-hexanoyl-l-homoserine lactone and N-3-oxo-octanoyl-L-homoserine lactone on growth of pathogenic bacteria(Pleiades Publishing Inc, 2015-11-01) Aybey, Aynur; Sinan, Selma; Askun, T.; Aybey, Aynur; Uludağ Üniversitesi; CJN-1872-2022Paraoxonase 1 (PON1) is human lactonase orginally described as enzyme that is capable of hydrolyzing organophosphates. The hypothesis suggested that this enzyme may also participate in attenuation of bacterial virulence through interfering with quorum sensing (QS). Recently, PON1 was shown to hydrolyze over 30 lactones. In the present study, human PON1 (hPON1) was purified using ammonium sulphate precipitation and Sepharose-4B-L-tyrosine-1-naphthylamine hydrophobic interaction chromatography. The purified enzyme had a specific activity of 11.89 U/mg protein and catalyzed the hydrolysis of N-hexanoyl-L-homoserine lactone (C10HSL) and N-3-oxo-octanoyl-L-homoserine lactone (3OC8HSL). The hydrolysis reaction was analyzed with HPLC. The K (M) values for hPON1 using 3OC8HSL or C10HSL as subtrate were calculated as 2.71 and 0.80 mM and V (max) values were detected as 1428.57 and 45.24 A mu moles mg(-1) min(-1), respectively. Also, effect of hPON1 on growth of pathogenic bacterial strains using the signal lactone molecules was investigated by microtiter plate assay. Our results demonstrated that hPON1 was responsible for inhibition of QS system by hydrolyzing of signal molecules and effecting bacterial growth.Item Synthesis, structural characterization and biological evaluation of novel mixed-ligand Co(II) complexes as quorum sensing inhibitory agent(Elsevier, 2020-02-15) Hopa, Çiğdem; Kara, Hülya; Aybey, Aynur; Uludağ Üniversitesi/Fen-Edebiyat Fakültesi/Biyoloji Bölümü.; EKR-3976-2022; 55353798200Antibiotic resistance is one of the biggest health problems of the twenty-first century. In order to cope with this global problem, alternative preventive strategies such as quorum sensing interruption are needed. Therefore, it is very important to develop new compounds with anti-quorum sensing activity. Here we present the synthesis and structural characterization of two new Co (II) complexes; [Co(btmpp)(NCO)(2)], 1 and [Co(btmpp)(NCSe)(2)], 2 (where btmpp is: 2,6-bis(3,4,5-trimethylpyrazolyl) pyridine). The crystal structures of both complexes is determined using single-crystal X-ray diffraction. The coordination environment of Co(II) atoms can be described as a distorted square pyramidal geometry. Both complexes is screened for antibacterial activities against Gram-positive (B. substilis) and Gram-negative (P. aeruginosa, S. typhimurium, S. sonnei, Y. enterocolitica) bacterial strains. The effects of these complexes on QS-regulated behaviors of bacteria such as swarming, and biofilm formation is also examined. All bacteria are found to be more sensitive to complex 2 than complex 1.