Environmental Biotechnology Laboratory, Institute for Environment and Resources (IER), Vietnam National University Ho Chi Minh City, Viet Nam.
Central Environmental Laboratory, School of Architecture, Civil and Environmental Engineering, Ecole Polytechnique Fédérale de Lausanne, Station 2, 1015 Lausanne, Switzerland.
J Environ Manage. 2018 May 15;214:149-156. doi: 10.1016/j.jenvman.2018.02.089. Epub 2018 Mar 8.
In Vietnam, intensive shrimp farms heavily rely on a wide variety of antibiotics (ABs) to treat animals or prevent disease outbreak. Potential for the emergence of multi-resistant bacteria is high, with the concomitant contamination of adjacent natural aquatic habitats used for irrigation and drinking water, impairing in turn human health system. In the present study, quantification of AB multi-resistant bacteria was carried out in water and sediment samples from effluent channels connecting a shrimp farming area to the Vam Co River (Long An Province, Vietnam). Bacterial strains, e.g. Klebsiella pneumoniae and Aeromonas hydrophila, showing multi-resistance traits were isolated. Molecular biology analysis showed that these strains possessed from four to seven different AB resistance genes (ARGs) (e.g. sul1, sul2, qnrA, ermB, tetA, aac(6)lb, dfrA1, dfr12, dfrA5), conferring multidrug resistance capacity. Sequencing of plasmids present within these multi-resistant strains led to the identification of a total of forty-one resistance genes, targeting nine AB groups. qPCR analysis on the sul2 gene revealed the presence of high copy numbers in the effluent channel connecting to the Vam Co River. The results of the present study clearly indicated that multi-resistant bacteria present in intensive shrimp cultures may disseminate in the natural environment. This study offered a first insight in the impact of plasmid-born ARGs and the related pathogenic bacteria that could emerged due to inappropriate antibiotic utilization in South Vietnam.
在越南，集约化虾养殖场大量使用各种抗生素（ABs）来治疗动物或预防疾病爆发。出现多耐药细菌的可能性很高，同时也污染了用于灌溉和饮用水的相邻自然水生栖息地，从而损害了人类健康系统。在本研究中，对连接虾养殖区和越南范河（隆安省）的废水通道中的水和沉积物样本进行了 AB 多耐药细菌的定量检测。分离出表现出多耐药特性的细菌菌株，例如肺炎克雷伯菌和嗜水气单胞菌。分子生物学分析表明，这些菌株具有从四个到七个不同的 AB 耐药基因（ARGs）（例如 sul1、sul2、qnrA、ermB、tetA、aac(6)lb、dfrA1、dfr12、dfrA5），赋予了多药耐药能力。对这些多耐药菌株中存在的质粒进行测序，共鉴定出 41 个耐药基因，针对 9 个 AB 组。qPCR 分析 sul2 基因表明，在连接范河的废水通道中存在高拷贝数。本研究清楚地表明，集约化虾养殖中存在的多耐药细菌可能会在自然环境中传播。本研究首次揭示了质粒携带的 ARGs 以及由于在南越不当使用抗生素而可能出现的相关病原菌的影响。
