Demirin Vibrio vulnificus’un klinik ve çevresel suşların büyümesi ve hemolizin/sitolizin ekspresyonu üzerine etkisi

Öz

Yüksek demir seviyeleri, oldukça ölümcül olan insan patojeni Vibrio vulnificus’un büyümesi ve virülansı ile güçlü bir şekilde ilişkilidir. Bu çalışma, farklı demir konsantrasyonları altında (7, 10, 15, 30 ve 50 μM) dört klinik ve dört çevresel V. vulnificus suşlarının, büyüme oranlarını ve hemolizin/sitolizin kodlayan genin (vvhA) ekspresyon seviyelerini incelemiştir. Ekspresyon seviyeleri 2-ΔΔCT yöntemine göre belirlenmiştir. Demir konsantrasyonu arttıkça vvhA transkripsiyon aşağı regülasyonu gözlenmiştir. Test edilen tüm suşlarda, 30 ve 50 uM ferrik klorür konsantrasyonları seviyesinde düşük konsantrasyonlara kıyasla anlamlı bir fark gözlenmiştir (p <0.001). Artan demir konsantrasyonu, tüm izolatların daha hızlı büyüme oranları ile anlamlı derecede ilişkiliydi (p <0.05). Demir seviyesinin artması, suşların büyüme oranını artırmıştır. Klinik suşların demir ile korelasyonu çevresel izolatlardan daha yüksek olarak gözlenlenmiştir. Bu çalışma, yüksek demir konsantrasyonları altında V. vulnificus’un klinik suşların nispeten artmış büyüme oranlarının, altta yatan bir hastalıktan dolayı aşırı demir yükü olan hastalarda bu patojenin daha yüksek virülansını açıklayabileceğini düşündürmektedir.

Anahtar Kelimeler

• büyüme
• demir
• patojen
• virülans
• vvhA

The effect of iron on the expression of hemolysin/cytolysin and growth of clinical and environmental strains of Vibrio vulnificus

Öz

Elevated levels of iron are strongly correlated with the growth and virulence of highly lethal human-pathogen Vibrio vulnificus. The present study examined the expression level of hemolysin/cytolysin-encoding gene (vvhA) and the growth rate of four clinical and four environmental strains of V. vulnificus under different iron concentrations (7, 10, 15, 30, and 50 μM). The expression levels of vvhA were determined according to the 2-ΔΔCT method. vvhA transcription was down-regulated as iron concentration increased. A significant difference was observed at the level of 30 and 50 μM ferric chloride concentrations compared to the lower concentrations in all the strains tested (p <0.001). Conversely, elevated iron concentration was significantly correlated with the higher growth rates of all the isolates (p <0.05). Increasing iron levels elevated the growth rate of the strains. Clinical strains appeared to be more correlated with high iron levels than environmental isolates. This study suggested that relatively increased growth rates of clinical strains of V. vulnificus under elevated iron concentrations might explain higher virulence of this pathogen in patients with iron overload from an underlying disease.

Anahtar Kelimeler

• growth
• iron
• pathogen
• virulence
• vvhA

Kaynakça

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