Tetrodotoxin-Producing Bacteria: Detection, Distribution and Migration of the Toxin in Aquatic Systems

Abstract

This review is devoted to the marine bacterial producers of tetrodotoxin (TTX), a potent non-protein neuroparalytic toxin. In addition to the issues of the ecology and distribution of TTX-producing bacteria, this review examines issues relating to toxin migration from bacteria to TTX-bearing animals. It is shown that the mechanism of TTX extraction from toxin-producing bacteria to the environment occur through cell death, passive/active toxin excretion, or spore germination of spore-forming bacteria. Data on TTX microdistribution in toxic organs of TTX-bearing animals indicate toxin migration from the digestive system to target organs through the transport system of the organism. The role of symbiotic microflora in animal toxicity is also discussed: despite low toxin production by bacterial strains in laboratory conditions, even minimal amounts of TTX produced by intestinal microflora of an animal can contribute to its toxicity. Special attention is paid to methods of TTX detection applicable to bacteria. Due to the complexity of toxin detection in TTX-producing bacteria, it is necessary to use several methods based on different methodological approaches. Issues crucial for further progress in detecting natural sources of TTX investigation are also considered.

Stable Tetrodotoxin Production by Bacillus sp. Strain 1839

“…Tetrodotoxin (TTX), being one of the most famous low molecular weight neurotoxins capable of voltage-gated sodium channels blocking in nerve and muscle tissues was found in a great variety of marine and terrestrial organisms and sea and freshwater sediments [1]. Its origin in organisms and ecosystems is still a controversial issue, but the discovery of numerous bacterial strains capable of TTX production isolated from the above-mentioned sources indicates the link between bacteria and toxin occurrence.…”

“…Another important question is the method for TTX detection. Despite different methodological approaches based on antigen specificity, neurotoxic effect, or physicochemical properties of the toxin used by researches in studies with bacteria, only liquid chromatography with tandem mass spectrometry could be considered the most specific and reliable to date [1].…”

Was macht Molche giftig?

“…Dies legt die Vermutung nahe, dass sie in ihrem Habitat entweder aus ihrer Nahrung Tetrodotoxin entnehmen und speichern oder dass sie zumindest eine Toxin‐Vorstufe, ebenfalls aus der Umwelt, benötigen, um daraus Tetrodotoxin zu synthetisieren. So werden für den marinen Bereich Bakterien als eigentliche Toxin‐Produzenten diskutiert . Aus Kugelfischen und marinen Invertebraten wie Krabben und dem erwähnten Oktopus wurden in der Tat eine Reihe von Bakterienstämmen isoliert, die in Kultur Tetrodotoxin produzierten, wenn auch nur in marginalen Mengen.…”

Genetic structure of the grey side-gilled sea slug (Pleurobranchaea maculata) in coastal waters of New Zealand

“…TTX is a potent neurotoxin found in numerous terrestrial and marine organisms, but neither the origin of TTX nor the causes of variation in TTX levels among species are understood. The structure of TTX suggests a microbial origin [7] and while certain microbes have been implicated in TTX production (reviewed in Magarlamov et al , 2017), all such claims have been refuted [8, 9]. Nonetheless, while not excluding a microbial origin, there is recognition that TTX in animals is often acquired via diet.…”