Department of Evolutionary and Environmental Biology, Faculty of Natural Sciences, University of Haifa, Mount Carmel, Haifa, Israel.
Department of Biology and Environment, Faculty of Natural Sciences, University of Haifa, Oranim, Tivon, Israel.
Sci Rep. 2017 Aug 11;7(1):7973. doi: 10.1038/s41598-017-08434-8.
Vibrio cholerae is the cause of cholera, a devastating epidemic and pandemic disease. Despite its importance, the way of its global dissemination is unknown. V. cholerae is abundant in aquatic habitats and is known to be borne by copepods, chironomids and fishes. Our aim was to determine if fish-eating birds act as vectors in the spread of V. cholerae by consuming infected fish. We determined the existence of V. cholerae in the microbiome of 5/7 wild cormorants' intestine. In three of these V. cholerae-positive wild cormorants, the presence of a gene for cholera toxin (ctxA) was detected. We subsequently tested eight captive, hand-reared cormorants, divided into two equal groups. Prior to the experiment, the feces of the cormorants were V. cholerae-negative. One group was fed exclusively on tilapias, which are naturally infected with V. cholerae, and the other was fed exclusively on goldfish or on koi that were V. cholerae-negative. We detected V. cholerae in the feces of the tilapia-fed, but not in the goldfish/koi-fed, cormorants. Hence, we demonstrate that fish-eating birds can be infected with V. cholerae from their fish prey. The large-scale movements of many fish-eating birds provide a potential mechanism for the global distribution of V. cholerae.
霍乱弧菌是霍乱的病原体，霍乱是一种具有毁灭性的传染病和大流行病。尽管其重要性不言而喻，但人们对其全球传播途径仍知之甚少。霍乱弧菌大量存在于水生环境中，已知可被桡足类、摇蚊和鱼类携带。我们的目的是确定食鱼鸟类是否通过食用受感染的鱼类而成为霍乱弧菌传播的媒介。我们确定了 5/7 只野生鸬鹚肠道微生物组中存在霍乱弧菌。在这 3 只霍乱弧菌阳性野生鸬鹚中，检测到霍乱毒素 (ctxA) 基因的存在。随后，我们测试了 8 只人工饲养的鸬鹚，分为两组，每组 4 只。实验前，鸬鹚的粪便中未检测到霍乱弧菌。一组只喂食天然感染霍乱弧菌的罗非鱼，另一组只喂食金鱼或锦鲤，这些锦鲤未感染霍乱弧菌。我们在喂食罗非鱼的鸬鹚的粪便中检测到了霍乱弧菌，但在喂食金鱼/锦鲤的鸬鹚的粪便中未检测到。因此，我们证明食鱼鸟类可以从它们的鱼猎物中感染霍乱弧菌。许多食鱼鸟类的大规模迁徙为霍乱弧菌的全球分布提供了一种潜在的机制。
