Krasner Ami, Durden Wendy Noke, Stolen Megan, Jablonski Teresa, Fabry Agatha, Page Annie, Marks Wendy, Costa Cecilia, Marley H C D, Fire Spencer
Department of Ocean Engineering and Marine Sciences, Florida Institute of Technology, Melbourne, FL 32901, USA.
Hubbs-SeaWorld Research Institute, Melbourne Beach, San Diego, FL 32951, USA.
Toxics. 2024 Nov 27;12(12):858. doi: 10.3390/toxics12120858.
Microcystin (MC), a hepatotoxin produced by cyanobacteria, was introduced into the Indian River Lagoon (IRL), Florida, in 2005 through freshwater outflows. Since then, MC has been detected in humans, domestic animals, and wildlife in the lagoon. Potential public health effects associated with MC exposure along the IRL include an increased risk of non-alcoholic liver disease among area residents. Yet, there are limited studies characterizing liver disease, as well as the potential role of MC, in humans and animals in this region. Thus, histopathology reports ( = 133) were reviewed in the stranded common bottlenose dolphin () ( = 156, 2005-2024) to describe liver lesions in this important IRL sentinel. Liver and fecal samples ( = 161) from stranded individuals were screened for MC via an enzyme immunoassay (ELISA). These samples were then confirmed via the 2-methyl-3-methoxy-4-phenylbutyric acid technique (MMPB) to evaluate whether liver histopathologic lesions were linked to MC exposure. Minimally invasive MC screening methods were also assessed using respiratory swabs and vapor. Inflammation (24%, = 32), fibrosis (23%, = 31), lipidosis/vacuolation (11%, = 15), and necrosis (11%, = 14) were the most common liver anomalies observed. These non-specific lesions have been reported to be associated with MC exposure in numerous species in the peer-reviewed literature. Ten bottlenose dolphins tested positive for the toxin via ELISA, including two individuals with hepatic lipidosis, but none were confirmed by MMPB. Thus, this study did not provide evidence for MC-induced liver disease in IRL bottlenose dolphins. Other causes should be considered for the lesions observed (e.g., heavy metals, metabolic disease, and endoparasites). Respiratory swabs require further validation as a pre-mortem MC screening tool in free-ranging wildlife.
微囊藻毒素（MC）是一种由蓝藻产生的肝毒素，于2005年通过淡水流出物进入佛罗里达州的印度河泻湖（IRL）。从那时起，在该泻湖的人类、家畜和野生动物中都检测到了MC。IRL沿线与MC暴露相关的潜在公共卫生影响包括该地区居民患非酒精性肝病的风险增加。然而，关于该地区人类和动物肝病以及MC潜在作用的研究有限。因此，对搁浅的宽吻海豚（Tursiops truncatus）（n = 156，2005 - 2024年）的组织病理学报告（n = 133）进行了回顾，以描述这一重要的IRL哨兵的肝脏病变。通过酶免疫测定（ELISA）对搁浅个体的肝脏和粪便样本（n = 161）进行MC筛查。然后通过2 - 甲基 - 3 - 甲氧基 - 4 - 苯基丁酸技术（MMPB）对这些样本进行确认，以评估肝脏组织病理学病变是否与MC暴露有关。还使用呼吸拭子和蒸汽评估了微创MC筛查方法。炎症（24%，n = 32）、纤维化（23%，n = 31）、脂肪变性/空泡化（11%，n = 15）和坏死（11%，n = 14）是观察到的最常见的肝脏异常。在同行评审的文献中，这些非特异性病变已被报道与许多物种的MC暴露有关。通过ELISA检测，有10只宽吻海豚毒素检测呈阳性，其中包括2只患有肝脏脂肪变性的个体，但通过MMPB均未得到证实。因此，本研究没有提供IRL宽吻海豚中MC诱导的肝病的证据。对于观察到的病变应考虑其他原因（例如重金属、代谢疾病和体内寄生虫）。呼吸拭子作为自由放养野生动物死前MC筛查工具需要进一步验证。
