Prisutnost bakterija otpornih na antibiotike kao dijela mikroflore uzgojenog lubina (Dicentrarchus labrax)

master's thesis

• Title (english): Presence of antibiotic-resistant bacteria as part of the microflora of farmed european seabass (Dicentrarchus labrax)
• Author: Ana Ramljak
• Mentor: Damir Kapetanović (mentor)
• Mentor: Tomislav Ivanković (mentor)
• Committee member: Jasna Hrenović (predsjednik povjerenstva)
• Committee member: Kristina Pikelj (član povjerenstva)
• Granter: University of Zagreb; Faculty of Science; (Department of Biology); Zagreb
• Defense date and country: 2020, Croatia
• Scientific / art field, discipline and subdiscipline: NATURAL SCIENCES; Biology

Abstract

Važnost akvakulture u proizvodnji hrane sve je veća, a među vrstama ribe koje se najviše uzgajaju u Jadranskom moru je lubin (Dicentrarchus labrax). Za liječenje oboljelih riba u uzgajalištima koriste se antibiotici koji doprinose otpornosti bakterija iz okoliša na antibiotike. Cilj rada bio je usporediti sastav mikrobnih zajednica u uzgajalištima sa i bez primjene antibiotika. Istaknuta je mikrobna zajednica kože lubina zbog važnosti za obranu organizma od patogena. Uzorkovanje je provedeno tijekom ljeta na uzgajalištima kod otoka Cresa i otoka Vrgade. Obavljena je fizikalno-kemijska analiza morske vode te mikrobiološka analiza kože, morske vode i sedimenta. Ispitana je otpornost bakterija na antibiotike i provedena je izolacija bakterijske DNA. Bakterije su identificirane određivanjem slijedova nukleotida gena 16S rRNA umnoženih u lančanoj reakciji polimerazom (PCR). U uzorcima morske vode, sedimenta i brisevima kože identificirano je 55 bakterijskih vrsta, većinom specifičnih za svaki tip uzorka. Uspoređujući uzgajališta, jedini zajednički rodovi u brisevima kože bili su Pseudomonas i Vibrio, dok za otpornost bakterijskih izolata s kože nije utvrđena statistički značajna razlika (p < 0,05). Vibrio alginolyticus, V. anguillarum i V. harveyi patogene su bakterije identificirane u brisevima kože s utvrđenom otpornošću na određene antibiotike. Rezultati ukazuju na potencijalan problem u uzgajalištima u slučaju pojave bolesti.

Abstract (english)

The importance of aquaculture is continually increasing in the food-producing sector, and one of the most farmed fish in Adriatic Sea is European seabass (Dicentrarchus labrax). Antibiotics are used for treatment of diseased fish in aquaculture, thus contributing to the spread of antibiotic resistance among environmental bacteria. The aim of this paper is to compare microbial communities between two fish farms, one which uses antibiotics for treatment and the other one which holds antibiotic-free certificate. Skin microbiome is highlighted due to the role of skin in defense against pathogens. Samples were collected during summer from two fish farms, near island Cres and near island Vrgada. Physico-chemical analysis of seawater was performed, as well as microbiological analysis of skin swabs, seawater and sediment. The antibiotic susceptibility test and bacterial DNA extraction were also performed. Bacteria identification was performed with determining the nucleic acid sequence of 16S rRNA gene amplified in polymerase chain reaction (PCR). There were 55 bacteria species identified in skin swabs, seawater and sediment samples. Species were mostly specific to each sample type. Only two bacterial genera, Pseudomonas and Vibrio, were identified in skin swabs samples from both fish farms. There was no statistically significant difference (p < 0,05) in antibiotic resistance of bacterial isolates from skin swabs between two fish farms. Pathogenic bacteria identified in skin swabs were Vibrio alginolyticus, V. anguillarum and V. harveyi, and showed resistance to certain antibiotics. The results indicate a potential problem for fish health management in case of disease outbreak.

• Keywords: akvakultura; lubin; otpornost na antibiotike
• Keywords (english): aquaculture; European seabass; antibiotic resistance
• Language: croatian
• URN:NBN: urn:nbn:hr:217:709931
• Study programme: Title: Enviromental Sciences; Study programme type: university; Study level: graduate; Academic / professional title: magistar/magistra struke znanosti o okolišu (magistar/magistra struke znanosti o okolišu)
• Type of resource: Text
• File origin: Born digital
• Access conditions: Open access
• Created on: 2020-09-16 10:35:30