Bacterial diversity and tetrodotoxin analysis in the viscera of the gastropods from Portuguese coast

Pratheepa, V.; Alex, Anoop; Silva, Marisa; Vasconcelos, Vı́tor

doi:10.1016/j.toxicon.2016.06.003

Cited by 20 publications

(26 citation statements)

References 66 publications

(68 reference statements)

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“…Among the Vibrio spp. isolated, a total of 53 strain contained the NRPS gene, which, according to other authors, is associated with the biosynthesis of toxins in bacteria [ 11 ]. The presence of the NRPS gene has been also observed in the samples where TTX was detected; nevertheless, this presence was also observed in other Vibrios isolated from samples where TTX was not detected.…”

Section: Discussionmentioning

confidence: 99%

“…Hypotheses on the occurrence of TTX include the TTX biosynthesis by host-associated bacteria TTX and a range of TTX analogues are evidenced to be produced by a wide range of bacterial species, including those from the genera of Vibrio , Bacillus , Aeromonas , Shewanella , Alteromonas , and Pseudomonas as reviewed in [ 11 ]. The link of TTX with marine phytoplankton was suggested by [ 9 ], who noted a correlation between TTX occurrence in shellfish and the prevalence of Prorocentrum minutum in seawater.…”

Section: Introductionmentioning

confidence: 99%

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Preliminary Results on the Evaluation of the Occurrence of Tetrodotoxin Associated to Marine Vibrio spp. in Bivalves from the Galician Rias (Northwest of Spain)

et al. 2018

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Tetrodotoxins (TTX) are a potent group of natural neurotoxins putatively produced by symbiotic microorganisms and affecting the aquatic environment. These neurotoxins have been recently found in some species of bivalves and gastropods along the European Coasts (Greece, UK, and The Netherlands) linked to the presence of high concentrations of Vibrio, in particular Vibrio parahaemolyticus. This study is focused on the evaluation of the presence of Vibrio species and TTX in bivalves (mussels, oysters, cockles, clams, scallops, and razor clams) from Galician Rias (northwest of Spain). The detection and isolation of the major Vibrio spp. and other enterobacterial populations have been carried out with the aim of screening for the presence of the pathways genes, poliketide synthase (PKS) and non-ribosomal peptide synthetase (NRPS) possibly involved in the biosynthesis of these toxins. Samples containing Vibrio spp. were analyzed by biochemical (API20E-galery) and genetic tests (PCR-RT). These samples were then screened for TTX toxicity by a neuroblastoma cell-based assay (N2a) and the presence of TTX was further confirmed by LC-MS/MS. TTX was detected in two infaunal samples. This is the first confirmation of the presence of TTX in bivalve molluscs from the Galician Rias.

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Section: Discussionmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

Preliminary Results on the Evaluation of the Occurrence of Tetrodotoxin Associated to Marine Vibrio spp. in Bivalves from the Galician Rias (Northwest of Spain)

et al. 2018

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“…Another promising method used to evaluate the potential of a given bacteria to produce TTX is to search for the genes involved in TTX biosynthesis using PCR analysis [22]. This method is less labor intensive, allows processing of a large number of samples simultaneously and does not require a large biomass of bacterial cells for analysis.…”

Section: Methods For Ttx Detectionmentioning

confidence: 99%

“…Ne-1. Another study revealed the presence of non-ribosomal peptide-transferase, which is presumed to take part in TTX guanidine group synthesis, in TTX-producing bacterial strains [22]. Decoding the biosynthetic pathways and functions of TTX in bacterial cells is crucial for investigating further natural sources of TTX.…”

Section: Conclusion and Future Perspectivementioning

confidence: 99%

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

Magarlamov

Melnikova

Chernyshev

2017

Toxins

119

105

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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.

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“…Tetrodotoxin is a non-proteic basic alkaloid neurotoxin (M W = 319.27 g/mol) with a tricyclic structure and a positively charged guanidinium group. Although found mainly in the liver and ovaries of Tetraodontiform fish, TTX it is not synthesized by fish but produced by bacterial strains, of the Vibrionaceae and Pseudomonas families, which were isolated from the intestine of the puffer fish Fugu vermicularis radiates [ 110 ]. TTX has also been described in invertebrates such as octopus, crabs, and starfish [ 111 ], and in terrestrial vertebrates such as newts and tree frogs from North America.…”

Section: Aptasensors For Aquatic Phycotoxins and Cyanotoxins Detecmentioning

confidence: 99%

Aptamer-Based Biosensors to Detect Aquatic Phycotoxins and Cyanotoxins

Cunha

Biltes

Sales

et al. 2018

Sensors

Self Cite

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Aptasensors have a great potential for environmental monitoring, particularly for real-time on-site detection of aquatic toxins produced by marine and freshwater microorganisms (cyanobacteria, dinoflagellates, and diatoms), with several advantages over other biosensors that are worth considering. Freshwater monitoring is of vital importance for public health, in numerous human activities, and animal welfare, since these toxins may cause fatal intoxications. Similarly, in marine waters, very effective monitoring programs have been put in place in many countries to detect when toxins exceed established regulatory levels and accordingly enforce shellfish harvesting closures. Recent advances in the fields of aptamer selection, nanomaterials and communication technologies, offer a vast array of possibilities to develop new imaginative strategies to create improved, ultrasensitive, reliable and real-time devices, featuring unique characteristics to produce and amplify the signal. So far, not many strategies have been used to detect aquatic toxins, mostly limited to the optic and electrochemical sensors, the majority applied to detect microcystin-LR using a target-induced switching mode. The limits of detection of these aptasensors have been decreasing from the nM to the fM order of magnitude in the past 20 years. Aspects related to sensor components, performance, aptamers sequences, matrices analyzed and future perspectives, are considered and discussed.

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Bacterial diversity and tetrodotoxin analysis in the viscera of the gastropods from Portuguese coast

Cited by 20 publications

References 66 publications

Preliminary Results on the Evaluation of the Occurrence of Tetrodotoxin Associated to Marine Vibrio spp. in Bivalves from the Galician Rias (Northwest of Spain)

Preliminary Results on the Evaluation of the Occurrence of Tetrodotoxin Associated to Marine Vibrio spp. in Bivalves from the Galician Rias (Northwest of Spain)

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

Aptamer-Based Biosensors to Detect Aquatic Phycotoxins and Cyanotoxins

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