title: Application of real-time PCR in the assessment of the toxic cyanobacterium Cylindrospermopsis raciborskii abundance and toxicological potential.
abstract: Cyanobacteria are prokaryotic photosynthetic microorganisms that pose a serious threat to aquatic environments because they are able to form blooms under eutrophic conditions and produce toxins. Cylindrospermopsis raciborskii is a planktonic heterocystous filamentous cyanobacterium initially assigned to the tropics but currently being found in more temperate regions such as Portugal, the southernmost record for this species in Europe. Cylindrospermopsin originally isolated from C. raciborskii is a cytotoxic alkaloid that affects the liver, kidney, and other organs. It has a great environmental impact associated with cattle mortality and human morbidity. Aiming in monitoring this cyanobacterium and its related toxin, a shallow pond located in the littoral center of Portugal, Vela Lake, used for agriculture and recreational purposes was monitored for a 2-year period. To accomplish this, we used the real-time PCR methodology in field samples to quantify the variation of specific genetic markers with primers previously described characterizing total cyanobacteria (16S rRNA), C. raciborskii (rpoC1), and cylindrospermopsin synthetase gene (pks). The results report the high abundance of both cyanobacteria and C. raciborskii in Vela Lake, with C. raciborskii representing 0.4% to 58% of the total cyanobacteria population. Cylindrospermopsin synthetase gene was detected in one of the samples. We believe that with the approach developed in this study, it will be possible to monitor C. raciborskii population dynamics and seasonal variation, as well as the potential toxin production in other aquatic environments.
authors.affiliation: CIMAR/CIIMAR, Laboratory of Ecotoxicology, Genomics and Evolution, University of Porto, Portugal.
authors.forename: Cristiana
authors.initials: C
authors.lastname: Moreira
authors.forename: António
authors.initials: A
authors.lastname: Martins
authors.forename: Joana
authors.initials: J
authors.lastname: Azevedo
authors.forename: Marisa
authors.initials: M
authors.lastname: Freitas
authors.forename: Ana
authors.initials: A
authors.lastname: Regueiras
authors.forename: Micaela
authors.initials: M
authors.lastname: Vale
authors.forename: Agostinho
authors.initials: A
authors.lastname: Antunes
authors.forename: Vitor
authors.initials: V
authors.lastname: Vasconcelos
mesh_terms: D000470:Alkaloids; D001426:Bacterial Proteins / Q000235:genetics; D001427:Bacterial Toxins; D001431:Bacteriological Techniques / Q000379:methods*; D000087522:Cyanobacteria Toxins; D046891:Cylindrospermopsis / Q000235:genetics / Q000302:isolation & purification* / Q000472:pathogenicity*; D017931:DNA Primers / Q000235:genetics; D004269:DNA, Bacterial / Q000235:genetics; D004275:DNA, Ribosomal / Q000235:genetics; D008025:Ligases / Q000235:genetics*; D011174:Portugal; D012336:RNA, Ribosomal, 16S / Q000235:genetics; D060888:Real-Time Polymerase Chain Reaction / Q000379:methods*; D014498:Uracil / Q000031:analogs & derivatives* / Q000096:biosynthesis; D014871:Water Microbiology
chemical_list: D000470:Alkaloids; D001426:Bacterial Proteins; D001427:Bacterial Toxins; D000087522:Cyanobacteria Toxins; D017931:DNA Primers; D004269:DNA, Bacterial; D004275:DNA, Ribosomal; D012336:RNA, Ribosomal, 16S; C089595:cylindrospermopsin; D014498:Uracil; D008025:Ligases