Identity and virulence properties of Aeromonas isolates from diseased fish, healthy controls and water environment in China
Identity and virulence properties of Aeromonas isolates from diseased fish, healthy controls and water environment in China
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DOI：
10.1111/j.1472-765x.2012.03281.x
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发表时间：
2012-09-01
影响因子：
2.4
通讯作者：
Liu, Y. J.
中科院分区：
文献类型：
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作者：
Hu, M.;Wang, N.;Liu, Y. J.
目的：了解中国病鱼气单胞菌的种类分布、健康对照和水环境；评价气单胞菌分离株中溶气素（aer）、细胞增殖性肠毒素（alt）、细胞毒性肠毒素（act）、温度敏感蛋白酶（eprCAI）和丝氨酸蛋白酶（ahp）基因的频率；并确定这些分离株的潜在致病性。方法与结果：通过对中国病鱼（42例）、健康鱼（120例）和水环境（40例）分离的202株气单胞菌的内源基因gyrB测序，鉴定出不同种类的气单胞菌，并采用PCR方法对aer、alt、act、eprCAI和ahp 5种毒力因子的分布进行分析。病鱼中最常分离出维氏气单胞菌（25/42;60%）和嗜水气单胞菌（14/42;33%）；在健康鱼类（90/120;75%）和水样（25/40;62.5%）中最常见的种类与维罗氏菌相似。5种毒力基因均有9%（19/202）存在，其中10株来自病鱼，9株被鉴定为Aer。类似于嗜水症。对于携带5种毒力基因的菌株，来自病鱼的菌株的平均50%致死剂量（LD50s）低于来自健康鱼和水环境的菌株。结论：维罗氏气单胞菌是最常见的菌种，但从病鱼和健康鱼中分离得到的菌株无显著差异。然而,爱尔兰。与嗜水菌相似，患病鱼的嗜水菌比健康鱼的嗜水菌更常见。病鱼气单胞菌的aer+alt+act+eprCAI+ahp+基因型比健康鱼和水环境气单胞菌更常见，aer+alt+act+eprCAI+ahp+基因型对斑马鱼的毒力比其他基因型更强。研究的意义和影响：水生环境中的气单胞菌种类繁多，具有相当大的毒力潜力，因此需要进行更仔细和深入的流行病学研究。
Aims: To investigate the species distribution in Aeromonas isolates from diseased fish, healthy controls and water environment in China; to evaluate the frequency of the aerolysin (aer), cytotonic enterotoxin (alt), cytotoxic enterotoxin (act), temperature-sensitive protease (eprCAI) and serine protease (ahp) genes in Aeromonas isolates; and to determine the potential pathogenicity of these isolates. Methods and Results: Two hundred and two Aeromonas isolates from diseased fish (n = 42), healthy fish (n = 120) and water environment (n = 40) in China were identified to species levels based on sequencing of the housekeeping gene gyrB, while the distribution of five virulence factors, including aer, alt, act, eprCAI and ahp, was investigated by PCR. Aeromonas veronii (25/42; 60%) and Aeromonas hydrophila (14/42; 33%) were the species most commonly isolated from diseased fish, while Aer.similar to veronii was the most common species in healthy fish (90/120; 75%) and water samples (25/40; 62.5%). All the five virulence genes were present in 9% (19/202), among which 10 strains were from diseased fish and nine were identified as Aer.similar to hydrophila. For the strains carrying five virulence genes, the average 50% lethal doses (LD50s) of strains from diseased fish were lower when compared with the strains from healthy fish and water environment. Conclusions: Aeromonas veronii is the most common species, but no significant difference exists in the isolates obtained from diseased fish and from healthy fish. However, Aer.similar to hydrophila isolates were significantly more frequent from diseased fish than from healthy fish. aer+alt+act+eprCAI+ahp+ was more frequent virulence genotype in Aeromonas isolates from diseased fish than from healthy fish and water environment, and the aer+alt+act+eprCAI+ahp+ isolates were more virulent to zebrafish comparing to the other genetic profiles. Significant and Impact of the Study: Aeromonas species in aquatic environments are various and have considerable virulence potential, and therefore, there is a need for more careful and intensive epidemiology studies.