二仁溪河口區域弧菌抗重金屬及抗藥能力之研究

Occurrence of heavy-metal and antibiotic resistance in Vibrio species isolated from Erhjen River estuary

陳淑娟(Shu-Chuan Chen)

指導教授 ： 洪慶宜

長榮大學/健康科學學院/職業安全與衛生學系(所)/碩士(2014年)

https://doi.org/10.6833/CJCU.2014.00046

摘要

近年來國外許多研究顯示微生物抗重金屬與抗藥性基因能存在於質體DNA中，並跨菌種傳遞，在受污染環境下，具抗藥性的致病菌可能更普遍存在。考量國內之人口、畜牧場密度高、廢污水處理率低及處理效果差等特性，探討污染環境對抗藥性致病菌分布的影響有其必要性。本研究以二仁溪底泥弧菌物種為研究對象，比較底泥重金屬含量與弧菌抗重金屬的相關性，並檢測抗重金屬能力與抗藥性是否關聯，弧菌抗重金屬與抗藥性能力並與七股底泥弧菌、花蓮北濱菌株比較，初探不同環境區域的弧菌的耐受力差異。本研究探討的重金屬包含銅、鋅、鎳；探討的抗生素包含gentamicin、Ciprofloxacin及tetracycline。
然而，本研究結果顯示，二仁溪底泥重金屬濃度與弧菌的重金屬最小抑制濃度無相關性(P>0.05)。三區域弧菌的各重金屬與各抗生素MIC間皆未具顯著性(P>0.05)，顯示抗重金屬能力與抗藥能力間不具關聯。與七股及北濱弧菌相較，二仁溪弧菌對gentamicin及ciprofloxacin抗藥性顯著較高(Kruskal-Wallis ANOVA，P值分別為0.008及0.007)；所有樣本皆對tetracycline有極高的抗藥性，顯示此類抗生素已無法治療弧菌感染。
此研究初步建構污染河川弧菌生態資訊，嘗試瞭解在此一有高重金屬污染潛能底泥環境，弧菌的生存策略；而獲知致病性弧菌的其抗藥程度，可作為公共衛生的參考。

關鍵字

弧菌 ； 重金屬 ； 抗生素 ； 最小抑制濃度 ； 二仁溪

並列摘要

Recent researches have indicated that the antibiotic-resistant gene and pollutant-resistant gene are co-exist on plasmid and subjected to conjugative transfer from cell to cell. Under the selective pressure of anthropogenic pollutants, antibiotic-resistant pathogens might present in a higher population than in a related pristine environment. Considering the situations of dense human population and pig farms with unsatisfied wastewater treatment practice, research on how pollution affects the distribution of antibiotic resistant pathogens is deemed necessary. To explicit the relationship between the occurrence of resisting strains and the anthropogenic stress, this research conducted investigation on metal and antibiotic susceptibility of Vibrio spp. in the estuary of Erhjen River, characterized by its long history of metal pollution by the past scrap metal factories and recent industrial activities, in southern Taiwan. Vibrio spp. isolated from Chiku Lagoon in Tainan, a related pristine water body in Southern Taiwan, as well as strains from Beibin in Hwalian, seashore located at Eastern Taiwan, were compared to extend the spatial variability. The study assessed three metals (Cu, Zn, and Ni) and three antibiotics (gentamicin, ciprofloxacin, and tetracycline).
The study suggested, however, metal susceptibility of Vibrio spp. isolated from Erhjen River was unrelated to environmental stress with non-significant correlation coefficients (P>0.05) between minimum inhibitory concentrations (MIC) for Cu, Zn, Ni and sediment concentrations for the same metals. There was also no relationship found between metal resistance and antibiotic resistance for the Vibrio spp. isolated from the three sampling area. Correlation coefficients between MIC for heavy metals and MIC for antibiotics were non-significance (P>0.05). Comparing with Chiku and Beibin strains, Vibrio spp. isolated in Erhjen had significantly higher MICs for gentamicin and ciprofloxacin (Kruskal-Wallis ANOVA, P=0.008 and 0.007, respectively). All isolated Vibrio were resistance to tetracycline, suggesting ineffective curability of the antibiotic.
The preliminary study explored the ecology of Vibrio in a highly polluted environment. Attempts were made to understand the survival strategy of Vibrio in sediment with potential of heavy metal and antibiotic contaminations. The findings are expected not only benefit to the scientific communities but also to the policy makers who may use the information to protect the seafood consumption safety as well as to regulate the uses of antibiotics and heavy metals in the watershed.

並列關鍵字

Vibrio ； heavy metal ； antibiotic ； MIC ； Erhjen River

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