粘桿菌素對斑馬魚胚胎之毒性並探討鈣離子對粘桿菌素的影響

Investigation of the toxicity of colistin in zebrafish embryos and the influence of calcium on the toxicity

林佳柔(Lin Jia-Rou)

指導教授 ： 林豊益

國立臺灣師範大學/理學院/生命科學系/碩士(2021年)

https://doi.org/10.6345/NTNU202100948

摘要

近年來因為抗生素的過度使用導致環境汙染的問題逐漸受到重視。目前在臨床上使用之粘桿菌素colistin 會對人體造成腎毒性及神經毒性等副作用，因此被列為對抗格蘭氏陰性細菌感染的最後一線用藥。在許多國家中粘桿菌素也被大量使用在畜產業上作為動物傳染病的防治，進而導致粘桿菌素隨著動物排泄物及未食用完畢的食物進入水域環境中，產生具有抗藥性的大腸桿菌。然而，粘桿菌素對水生動物可能的危害卻仍未被研究。因此本研究目的是利用斑馬魚胚胎為模式以探討粘桿菌素暴露對魚類可能產生的毒性以及水中離子濃度對其毒性之影響。結果發現斑馬魚胚胎暴露粘桿菌素 96小時之半致死濃度約為3 μM，死亡個體出現皮膚細胞破損現象，但未產生發育異常與畸形；在亞致死濃度下桿菌素會減少側線毛細胞數量以及離子細胞數量，並損害角質細胞結構。 綜合上述 在隨時間的觀察發現 魚體皮膚角質細胞在暴露粘桿菌素後會逐漸破損，最終導致皮膚細胞瓦解，體內離子失衡，魚體死亡。藉由改變水中的離子濃度，發現鈣離子濃度對粘桿菌素的毒性有關鍵性的影響。提高鈣濃度可以有效減低其毒性，降低鈣濃度會提高毒性。本研究證實了粘桿菌素在水域汙染後可能對魚類產生危害，藉由提高水中的鈣離子濃度可減低其毒性。

關鍵字

粘桿菌素 ； 毒性 ； 毛細胞 ； 角質細胞 ； 離子細胞

並列摘要

In recent years, the problem of environmental pollution caused by the excessive use of antibiotics has gradually attracted attention. In clinical, colistin is listed as the last-line drug to combat Gram-negative bacterial infections due to the side effects such as nephrotoxicity and neurotoxicity to the human. However, colistin has been widely used in the animal industry to prevent and treat animal infectious diseases in many countries. Colistin was found to contaminate water environments and produced drug-resistant Escherichia coli. However, the potential toxicity of colistin to aquatic animals has not been studied yet. The purpose of this study was to use zebrafish embryos as a model to explore the toxicity of colistin. The result showed that the 50% lethal concentration after 96 hrs colistin exposure was about 3 μM. The skin was damaged in the dead individual. However, developmental abnormalities and deformities were not found. Colistin decreased the number of lateral hair cells and ionocytes, and damaged the keratinocytes structure. We found that skin keratinocytes were severely damaged and detached after exposure, leading to hypotonic swelling of the yolk sac, loss of ion contents, cell lysis, and eventual death. We also found that increasing the calcium concentration of water reduced the toxicity of colistin. In conclusion, this study demonstrated that colistin can pose a threat to fishes by impairing skin cells and functions.

並列關鍵字

colistin ； toxicity ； hair cell ； keratinocyte ； ionocyte

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