氯霉素暴露对杂色鲍免疫活性的影响

Effects of chloromycetin exposure on immunity activity of Haliotis diversicolor

杂色鲍的免疫机能主要是由血细胞以吞噬的方式来完成.本研究将杂色鲍分别暴露在1、2、5μg/cm3不同含量氯霉素的水体中60 d(每天暴露4 h),检测其主要免疫指标的变化.实验结果表明,经氯霉素暴露实验后,杂色鲍的主要免疫指标出现了下降.对照组与各药物含量组(1、2、5μg/cm3)中杂色鲍血细胞对溶藻弧菌的吞噬率分别为89.83%±3.66%、75.33%±4.89%、68.67%±5.05%和37.00%±9.21%;其吞噬指数分别为3.84±0.27、2.54±0.35、2.12±0.47和1.18±0.32;其血细胞密度分别为(2.72±0.33)×107、(1.87±0.09)×107、(1.46±0.17)×107、(1.03±0.14)×107个/cm3.对照组与各药物含量组在水温31℃高温胁迫下杂色鲍半致死时间(LT50)分别为10、8、6、4 h.各实验组的壳长、体重生长率、成活率与对照组比较,高含量组均显著小于对照组.含量为1μg/cm3和2μg/cm3的氯霉素暴露对杂色鲍的生长有轻微的促进作用.各实验组酸性磷酸酶(ACP)、碱性磷酸酶(AKP)、超氧化物歧化酶(SOD)的酶活指标变化与氯霉素的暴露含量无明显相关性.

Antibiotics are often used for disease prevention in the breeding of abalone. However, the effect of anti- biotics on abalone disease prevention is often unstable, and the abuse of antibiotics has had adverse effects on the ecological environment, and may in fact endanger food safety. Furthermore, antibiotics may damage the immune system of abalone and increase the death rate of abalone. Therefore, studying the influence of antibiotics on im- mune characteristics in Haliotis diversicolor has important practical significance and application value. After expo- sure in 0, 1, 2, and 5 ixg/cm^3 chloromycetin for 60 days （4 h every day）, the main immune indices ofH. diversi- color were measured. Our study indicated that some indices declined upon treatment with antibiotics. The phagocy-tosis rate （ % ） of blood corpuscles to Vibiro alginolyticus in 0, 1, 2, and 5 I.Lg/cm3 were 89.83 ± 3.66, 75.33 ＋ 4.89, 68.67 ± 5.05, and 37.00 ± 9.21, respectively. The phagocytosis index for each treatment was 3.84 ±O. 27, 2.54 ＋0.35, 2.12 ＋0.47, and 1.18 ＋0.32, respectively. The blood corpuscles density also decreased af- ter chloromycetin exposure, with （2.72 ＋ 0.33 ）× 107 cells/cm3, （ 1.87 ± 0.09） ×10v cells/era3, （ 1.46 ＋ 0. 17 ） ×107 eells/cm3, and （1.03±0.14） ×107 cells/cm3for 0, 1,2, and 5 I.zg/cm3 chloromycetin, respectively. The activity of the exposed abalone was determined by stressing at 31 ~C water temperature. The LTso for 0, 1, 2, and 5 ~g/cmz treatments were determined to be 10, 8, 6, and 4 h, respectively. The shell growth, weight growth and survival rate, under treatments were significantly lower than those of the control group. The 1 and 2μg/em3ehloro- mycetin exposures were observed to have a slight positive effect on the growth of H. diversieolor. However, changes in activities of ACP, AKP, and SOD had no correlation with chloromycetin exposure. The current study showed that multiple immune indices all declined in H. diversieolor after the treatment with ehloramphenicol; therefore, long- term use of antibiotics is likely to have adverse effects on immune and other physiological functions important for the breeding of abalone.