Global geographical and historical overview of cyanotoxin distribution and cyanobacterial poisonings

Morphological and Molecular Identification of Microcystin-Producing Cyanobacteria in Nine Shallow Bulgarian Water Bodies

“…Some hazardous toxigenic species from the phylum Cyanoprokaryota/Cyanobacteria (known also as blue-green algae) can form harmful algal blooms commonly abbreviated as CyanoHABs. The increasing and widespread concern regarding the serious threat which these algae and their toxins (cyanotoxins) pose to human and animal health is consistent with the recent growth in interest on the topic [1]. In Bulgaria, from 120 water bodies (WBs) investigated during the period 2000-2015, cyanoprokaryotic blooms were recorded in 14 WBs, and in 16 WBs cyanotoxins (mostly microcystins-MCs, but also nodularins-NODs and saxitoxins-SXTs) were found [2,3].…”

“…The results obtained during the study indicated the MC risk on studied WBs caused by the presence of 28 MC-producing strains of the genus Microcystis, seven species of which were confirmed by LM. The data obtained from the combination of conventional microscopic studies with PCR-sequencing: (1) proved the presence of toxic strains in M. wesenbergii; (2) allowed strongly to suppose their existence in M. natans; (3) confirmed the well-known presence of toxigenic strains in M. aeruginosa; (4) showed the significant morphological variability of Microcystis colonies with many transitional colonies, and, in combination with the complex genetic pool, supported the earlier opinions that taxonomic revision of the genus is needed, and (5) once more demonstrated that genetic sequencing, and the use of HEPF × HEPR pair of primers in particular, can efficiently serve in water quality monitoring for identifying the potential risk from MCs, even in cases of low amounts of Microcystis in the water. When considering the results obtained by other methods from the study of the same WBs in the same period [4], we share the widely accepted opinion that until a unique method is adopted, a combination of different approaches is more desirable, and even needed, in the studies of CyanoHABs.…”

A Mini Review on Microcystins and Bacterial Degradation

“…Metcalf et al [20] also indicated that MCs can be produced in desert environments. More than 30 cyanobacterial species are capable to produce MCs [21]. Interestingly much attention has been given to Microcystis sp.…”

“…Microcystins have shown humans and animals toxicity [9,21,42,43] with lethal dose LD 50 by the intraperitoneal route ranging from 50 (MC-LR) to 600 (MC-RR) µg/kg and oral LD 50 of 5000 µg/kg as indicated in mice [8]. The primary mechanism of MCs toxicity is the inhibition of protein phosphatases (PP1) and protein phosphatases (PP2A).…”

“…A number of human and animal fatalities and severe poisonings have been attributed to MC-containing Microcystis blooms [9,21,57,58]. MCs were noted to affect the growth and physiological functions of aquatic and terrestrial animals, livestock, pets and wildlife due to their bioaccumulation of these toxins.…”