Naslov
Autochthonous intestinal Enterovibrio sp. or commercial Lactobacillus casei: Which one fits better as an immunostimulator in the European sea bass (Dicentrarchus labrax)?

Autori
Hrabar, Jerko ; Bušelić, Ivana ; Vrbatović, Anamarija ; Radonić, Ivana ; Jozić, Slaven ; Mladineo, Ivona

Vrsta, podvrsta i kategorija rada
Sažeci sa skupova, sažetak, ostalo

Izvornik
Book of Abstracts of 6th Croatian Congress of Microbiology / Roberto Antolović - Zagreb : Hrvatsko mikrobiološko društvo, 2016, 48-48

Skup
6th Croatian Congress of Microbiology

Mjesto i datum
Sveti Martin na Muri, Hrvatska, 15.06.2016. - 18.06.2016

Vrsta sudjelovanja
Predavanje

Vrsta recenzije
Domaća recenzija

Ključne riječi
autochthonous bacteria; peripheral blood leukocytes; probiotic; sea bass

Sažetak
Greece, Turkey, Italy, Spain, Croatia and Egypt are the biggest producers of the European sea bass (Dicentrarchus labrax). However, specific rearing systems in different geographic regions can express different etiological and epidemiological picture of the fish health status, necessary to account for when planing prophylactic measures. Among those, the use of probiotics represents a safe, environmentally sustainable and economic option in intensive aquaculture, where different bacteria have been already tested as probiotics ; Lactobacillus fructivorans, L. plantarum, L. delbruckii delbruckii, Enterococcus spp., Bacillus subtilis , Tetraselmis chuii and Phaeodactylum tricornutum. Bacteria of autochthonous origin have been accepted as having a greater capability to compete with resident pathogens, being more prone to dominate and persist over other potentially pathogenic microbes. Therefore, we have isolated an autochthonous bacteria from intestine of farmed sea bass ; Enterovibrio sp., chosen based on its biochemical properties, and compared its immunomodulatory properties with a commercially available Lactobacillus casei. Both bacteria were cultured, PCR-identified and tested for pathogenicity in fish at two concentrations (low 105 CFU/ ml and high 108 CFU/ ml). For in vitro assay, sea bass peripheral blood leukocytes (PBL) were prepared using 51% iso- osmotic Percoll solution, seeded in 6-well plates with L-15 medium (with 15% FCS and 1% penicillin/streptomycin). After 2 h of PBL settlement in wells, bacterial isolates were added in culture media (108 CFU/ ml), except in control wells and left for 1 h, 3 h, 5 h and 12 h. RNA was extracted, quantified and transcribed in cDNA, and sea bass specific primers for target genes ; lysozyme g (lys), Mx protein (Mx), caspase 3 (casp3), inteleukine 10 (IL-10), tumour necrosis factor α (TNF-α), and reference genes 18s rRNA, β-actin (β-act) and elongation factor (ef) were used for real-time PCR in a LightCycler 480 System. Although immunomodulatory properties of both isolates were evident, better effect was observed with L. casei. Target genes were differentially expressed already 1 h post-stimulation compared to untreated control PBL, and lasted till the termination of the experiment. Similar expression pattern was observed in cells stimulated by both bacteria.

Izvorni jezik
Engleski

Znanstvena područja
Biologija, Veterinarska medicina, Biotehnologija

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