Publication: Çeşitli liken özütlerinin escherichia coli türü bakterilerde anti-quorum sensing, anti-biyofilm ve anti-efflux pompası özelliklerinin incelenmesi
Abstract
Escherichia coli’nin antibiyotik direnci, dünya genelinde halk sağlığını ayrıca gıda ve içme sularının güvenliğini ciddi oranda tehdit etmektedir. Son yıllarda çoklu ilaç direnci gösteren bakteri enfeksiyon vakalarındaki artış tedaviyi zorlaştırmanın yanında tedavi maliyetinin de artmasına sebep olmaktadır. E. coli’nin çoklu ilaç direnci göstermesindeki en önemli mekanizmalardan birinin efflux pompa sistemleri olduğu bilinmektedir. Efflux pompaları, bakteri hücresi için zararlı moleküllerin dışa atımında görevli olmasının yanında biyofilm oluşumunda gerekli ekzopolisakkaritlerin de hücre dışına atımında görev aldığı bilinmektedir. İdrar yolu enfeksiyonlarında en sık görülen etmen olan E. coli, kataterler gibi medikal gereçlerde oluşturduğu biyofilm formu nedeniyle hem enfeksiyonların devamlılığını sağlamakta, hem de planktonik formlara göre antbiyotiğe daha yüksek direnç göstermektedir. E. coli’de bu formun ve çeşitli virulans faktörlerinin ayrıca çeşitli direnç genlerinin aktivasyonunun bakteriyel iletişim mekanizması olan Quorum Sensing sistemiyle ilişkili olduğu bilinmektedir. Bu mekanizmaların inhibisyonunun doğal kaynaklar kullanılarak gerçekleştirilmesinin, düşük maliyetli ve sürdürülebilir bir şekilde antibiyotik direnci ile mücadeleye katkı sağlayacağı düşünülmektedir. Bu bilgiler ışığında yapmış olduğumuz çalışmada, Bursa-Alaçam, Balıkesir ve Kastamonu bölgelerinden toplanan çeşitli likenlerin tür tayinleri yapılmış ve aseton özütleri çıkarılmıştır. Elde edilen özütlerin E. coli üzerinde anti-biyofilm, anti-QS ve anti-efflux özellikleri araştırılmıştır. Cetraria islandica ve Umbilicaria. deusta aseton özütlerinin kristal viyole boyama metoduyla anti-biyofilm özellikleri incelendiğinde, uygulanan en yüksek konsantrasyonların negatif kontrole göre sırasıyla yaklaşık olarak %75 ve %85 inhibisyon etkisi olduğu görülmüştür. Aynı liken özütlerinin EtBr birikim metoduyla efflux özellikleri incelendiğinde pozitif kontrol olarak kullanılan klorpromazine yakın bir aktivite gösterdiği gözlenmiştir. Elde edilen sonuçların antibiyotik direnç mekanizmalarını potansiyel olarak baskılayabileceği ve yapılacak ileri çalışmalara yol gösterici olarak literatüre katkı sağlayacağı düşünülmektedir.
Antibiotic resistance of Escherichia coli seriously threatens public health and the safety of food and drinking water worldwide. In recent years, the increase in cases of multi-drug resistant bacterial infections not only makes treatment difficult, but also causes an increase in the costs. It is known that one of the most important mechanisms for multi-drug resistant E. coli is efflux pump systems. Efflux pumps are involved in excretion of harmful compounds from bacteria cells, as well as the excretion of exopolysaccharides necessary for biofilm formation. E. coli, which is the most common factor in urinary tract infections, not only ensures the continuity of infections, but also shows higher resistance to antibiotics compared to planktonic forms, due to its biofilm form on medical equipments such as catheters. It is known that biofilm form and various virulence factors in addition to activation of various resistance genes in E. coli are associated with quorum sensing system, which is known as the bacterial communication mechanism. It is thought that the inhibition of these systems using natural resources will contribute to the fight against antibiotic resistance in a low-cost and sustainable way. Accordingly in this study, various lichens collected from Bursa-Alaçam, Balıkesir and Kastamonu regions were identified and their acetone extracts were obtained. Anti-biofilm, anti-QS and anti-efflux properties of the obtained extracts against E. coli were investigated. Anti-biofilm properties of C. islandica and U. deusta acetone extracts were examined via crystal violet staining method. It was observed that the highest applied concentrations had inhibition percentages of approximately 75% and 85%, respectively. When the efflux properties of the same lichen extracts were examined through EtBr accumulation method, it was observed that they performed close to chlorpromazine, which was used as a positive control. It is thought that the results obtained can potentially suppress antibiotic resistance mechanisms and will contribute to the literature by guiding further studies.
Antibiotic resistance of Escherichia coli seriously threatens public health and the safety of food and drinking water worldwide. In recent years, the increase in cases of multi-drug resistant bacterial infections not only makes treatment difficult, but also causes an increase in the costs. It is known that one of the most important mechanisms for multi-drug resistant E. coli is efflux pump systems. Efflux pumps are involved in excretion of harmful compounds from bacteria cells, as well as the excretion of exopolysaccharides necessary for biofilm formation. E. coli, which is the most common factor in urinary tract infections, not only ensures the continuity of infections, but also shows higher resistance to antibiotics compared to planktonic forms, due to its biofilm form on medical equipments such as catheters. It is known that biofilm form and various virulence factors in addition to activation of various resistance genes in E. coli are associated with quorum sensing system, which is known as the bacterial communication mechanism. It is thought that the inhibition of these systems using natural resources will contribute to the fight against antibiotic resistance in a low-cost and sustainable way. Accordingly in this study, various lichens collected from Bursa-Alaçam, Balıkesir and Kastamonu regions were identified and their acetone extracts were obtained. Anti-biofilm, anti-QS and anti-efflux properties of the obtained extracts against E. coli were investigated. Anti-biofilm properties of C. islandica and U. deusta acetone extracts were examined via crystal violet staining method. It was observed that the highest applied concentrations had inhibition percentages of approximately 75% and 85%, respectively. When the efflux properties of the same lichen extracts were examined through EtBr accumulation method, it was observed that they performed close to chlorpromazine, which was used as a positive control. It is thought that the results obtained can potentially suppress antibiotic resistance mechanisms and will contribute to the literature by guiding further studies.