Izolacija in karakterizacija bakterij s kože močerila in njegovega vodnega okolja

Bokan, Ivana (author), Turk, Martina (mentor)

Močeril je, zaradi svoje edinstvene biologije, najbolj prepoznavna žival v dinarskem podzemlju. Sodi med najbolj ogrožene živali v Evropi, ogrožajo jo predvsem različni patogeni in spremembe v njenem naravnem okolju, ki so predvsem posledica onesnaževanja. Cilj magistrskega dela je bil raziskati sestavo bakterijske kožne mikrobiote močerila in njegovega vodnega okolja. S kože 32 osebkov podvrste Proteus anguinus anguinus in dveh osebkov podvrste Proteus anguinus parkelj ter 18 vzorcev vode različnih lokacij smo izolirali 2196 aerobnih kemoorganoheterotrofnih bakterij. Ugotovili smo, da sta sestavi kožne in vodne mikrobiote precej podobni, sestava pa je izredno pestra. Največ izolatov pripada rodovom Pseudomonas, Aeromonas, Acinetobacter, Flavobacterium in Bacillus, ki so ubikvitarni, izolirali smo jih iz brisov in vode, zato sklepamo, da večina kožne mikrobiote močerila izvira iz njegovega vodnega okolja. Izolati rodov Brevundimonas, Janthinobacter, Serratia in Stenotrophomonas, pa bi po literaturi lahko bili sestavni del zaščitne mikrobiote dvoživk in tako imeli podobno funkcijo tudi pri močerilu. Primerjava mikrobiote kože med prostoživečimi osebki in osebki v ujetništvu je pokazala, da je diverziteta izolatov večja pri živalih v ujetništvu. Primerjava med zdravimi in bolnimi osebki pa je pokazala, da je diverziteta bakterij večja pri zdravih osebkih. Preverili smo tudi odpornost 112 od 2196 izolatov proti ampicilinu, cefotaksimu, imipenemu, tetraciklinu, eritromicinu, kanamicinu, enrofloksacinu in kloramfenikolu. Največ testiranih sevov je bilo odpornih proti cefotaksimu (47,5 %), nižji delež pa proti tetraciklinu (3,3 %). Enrofloksacin, ki se uporablja v veterinarski medicini, je učinkoval proti večini testiranih izolatov. Z metodami strojnega učenja smo ugotovili, da ni podobnosti med vzorci glede lokacije, sezono vzorčenja ter tipom vzorca. Statistično značilno razliko med skupinami vzorcev smo dokazali samo med vzorci iz lokacij Jelševnik in jamski laboratorij Tular. Magistrska naloga je bila opravljena v okviru projekta 'Porajajoči mikrobni patogeni človeške ribice (Proteus anguinus), endemne troglobiontske dvoživke'.

• Language: Slovenian
• Keywords: močeril, Proteus anguinus, bakterije, mikrobiota kože, mikrobiota vode, odpornost proti antibiotikom
• Work type: Master's thesis/paper
• Typology: 2.09 - Master's Thesis
• Organization: BF - Biotechnical Faculty
• Place of publishing: Ljubljana
• Publisher: [I. Bokan]
• Year: 2021
• PID: 20.500.12556/RUL-126333
• UDC: 579.25/.26:597.92:577.2.088
• COBISS.SI-ID: 60161795
• Publication date in RUL: 17.04.2021

Secondary language

• Language: English
• Title: Isolation and characterization of the bacteria from the skin of the olm and its aquatic environment

Abstract

Due to its unique biology, the blind cave salamander (olm) is the most recognizable animal in the Dinaric underground. It is one of the most endangered animals in Europe, threatened mainly by various pathogens and changes in its natural environment, mainly by pollution. The aim of the master thesis was to investigate the composition of the bacterial skin microbiota of the olm and its aquatic environment. The 2196 aerobic chemoorganoheterotrophic bacteria were isolated from the skin of 32 specimens of the subspecies Proteus anguinus anguinus and two specimens of the subspecies Proteus anguinus parkelj, as well as 18 water samples from different locations. We found that the composition of microbiota is highly diverse and when comparing the cutaneous and aqueous microbiota they are quite similar. Most isolates belong to the genera Pseudomonas, Aeromonas, Acinetobacter, Flavobacterium and Bacillus, which are ubiquitous, we isolated them from swabs and water, so we conclude that most of the skin microbiota originates from their aquatic environment. Isolates of the genera Brevundimonas, Janthinobacter, Serratia and Stenotrophomonas could be an integral part of the protective microbiota of amphibians according to the literature and thus have a similar function in the salamander. The comparison of skin microbiota between wild and captive specimens showed that the diversity of isolates is higher in captive animals. Comparison of skin microbiota between healthy and diseased specimens showed that bacterial diversity was greater in healthy specimens. We also tested the resistance of 112 of the 2196 isolates to ampicillin, cefotaxime, imipenem, tetracycline, erythromycin, kanamycin, enrofloxacin and chloramphenicol. Most strains tested were resistant to cefotaxime (47.5%) and a smaller proportion to tetracycline (3.3%). Enrofloxacin, used in veterinary medicine, was effective against most of the isolates tested. Using machine learning methods, we found that there was no similarity between samples in terms of location, sampling season, and sample type. A statistically significant difference between sample groups was only found between samples from different sites, namely between Jelševnik and the Tular cave laboratory sites. The master thesis was completed as part of the project 'Emerging microbial threats to endemic troglobiotic amphibian Proteus anguinus'.

• Keywords: blind cave salamander, Proteus anguinus, bacteria, skin microbiota, water microbiota, antibiotic resistance