title: Genetic variability of the invasive cyanobacteria Cylindrospermopsis raciborskii from Bir M'cherga reservoir (Tunisia).
abstract: Cylindrospermopsis raciborskii is an invasive freshwater cyanobacteria of tropical origin, also found in temperate regions. Due to its known ability to produce potent toxins, such as cylindrospermopsin and the paralytic shellfish poisoning, this species is of major concern from a water quality perspective. This study presents a genetic characterization of four C. raciborskii strains isolated from the Bir M'cherga Tunisian reservoir. The toxicity assessment was investigated via molecular biology tools, which suggested that all the isolated strains were not producing cylindrospermopsin, saxitoxin, or microcystin. This result was further confirmed by HPLC and MALDI-TOF analyses. However, we report for the first time in C. raciborskii the presence of mcyA and mcyE, two segments of the microcystin synthetase mcy cluster. All the strains were identified taxonomically based on the 16S rRNA sequences, and their phylogenetic relationships were assessed using the rpoC1 region. Tunisian strains formed a distinct clade separated from the other African strains.
authors.affiliation: Unité de Recherche Ecosystèmes et Ressources Aquatiques, Institut National Agronomique de Tunisie, 43, Avenue Charles-Nicolle, 1082, Tunis Mahrajène, Tunisie.
authors.forename: Afef
authors.initials: A
authors.lastname: Fathalli
authors.forename: Amel Ben Rejeb
authors.initials: AB
authors.lastname: Jenhani
authors.forename: Cristiana
authors.initials: C
authors.lastname: Moreira
authors.forename: Joana
authors.initials: J
authors.lastname: Azevedo
authors.forename: Martin
authors.initials: M
authors.lastname: Welker
authors.forename: Mohamed
authors.initials: M
authors.lastname: Romdhane
authors.forename: Agostinho
authors.initials: A
authors.lastname: Antunes
authors.forename: Vitor
authors.initials: V
authors.lastname: Vasconcelos
mesh_terms: D000470:Alkaloids; D001427:Bacterial Toxins; D002851:Chromatography, High Pressure Liquid; D000087522:Cyanobacteria Toxins; D046891:Cylindrospermopsis / Q000145:classification / Q000235:genetics* / Q000302:isolation & purification / Q000378:metabolism; D004269:DNA, Bacterial / Q000235:genetics; D005618:Fresh Water / Q000382:microbiology; D014644:Genetic Variation; D052998:Microcystins / Q000096:biosynthesis*; D005810:Multigene Family; D010802:Phylogeny; D012336:RNA, Ribosomal, 16S / Q000235:genetics; D012530:Saxitoxin / Q000096:biosynthesis*; D019032:Spectrometry, Mass, Matrix-Assisted Laser Desorption-Ionization; D014416:Tunisia; D014498:Uracil / Q000031:analogs & derivatives* / Q000096:biosynthesis; D014871:Water Microbiology; D014881:Water Supply
chemical_list: D000470:Alkaloids; D001427:Bacterial Toxins; D000087522:Cyanobacteria Toxins; D004269:DNA, Bacterial; D052998:Microcystins; D012336:RNA, Ribosomal, 16S; C089595:cylindrospermopsin; D012530:Saxitoxin; D014498:Uracil; C078588:microcystin