Konjugativni plazmidi in filogenetske skupine sevov bakterije Escherichia coli, izoliranih iz perutnine

Lovšin, Žana (author), Ambrožič Avguštin, Jerneja (mentor), Zorman-Rojs, Olga (comentor)

Analizirali smo 106 izolatov bakterije Escherichia coli, ki so jih osamili na Veterinarski fakulteti Univerze v Ljubljani iz vzorcev pridobljenih na različnih perutninskih farmah v Sloveniji. Pri 35,85 % izolatov smo potrdili prisotnost konjugativnih plazmidov, ki posredujejo fenotipsko odpornost proti ampicilinu, tetraciklinu, cefotaksimu, kloramfenikolu ali trimetoprimu, proti ciprofloksacinu in kolistinu ni bil odporen noben izolat. Največ konjugativnih plazmidov smo dokazali v izolatih iz zraka, fecesa in krme v hlevih, najmanj pa pri jatah s kolibacilozo (visok pogin). Za potrditev pravih transkonjugant smo uporabili različne molekularne metode, vključno z ugotavljanjem filogenetske skupine in profilov ERIC-PCR donorja in transkonjugant. V povezavi s filogenetskimi skupinami smo primerjali tudi prvotni in prenovljeni protokol za razvrščanje E. coli v skupine. Med drugim smo ugotovili, da se nekateri izolati, iz prvotne skupine A1 s prenovljenim premestijo v skupino C, kar nam olajša razlikovanje med donorji in transkonjugantami. Skupaj je bilo v druge skupine premeščenih 26,42 % izolatov. Zaradi možne povezave med uvrstitvijo v filogenetsko skupino in prisotnostjo nekaterih genov za dejavnike virulence smo analizirali prevalenco izbranih genov z zapisom za adhezine, sisteme za privzem železa, izogibanje imunskemu sistemu, toksine in porin pri izolatih v posamezni filogenetski skupini. Ugotovili smo, da je bilo največ izolatov z dejavniki virulence iz skupine B2, najmanj pa iz skupine A. Zanimiva je skupina F, v kateri so večinoma izolati iz jat s kolibacilozo (visok pogin), ki imajo zapise za več dejavnikov virulence hkrati. Med najpomembnejšimi so sistemi za privzem železa; pri vseh izolatih skupine F so namreč prisotni kar trije. Zanimivo je tudi, da iz te skupine ni bilo nobenega izolata, iz katerega bi s konjugacijo lahko prenesli genski zapis/e za odpornost.

• Language: Slovenian
• Keywords: biologija, Escherichia coli, perutnina, konjugativni plazmidi, odpornost proti protimikrobnim učinkovinam, filogenetske skupine, dejavniki virulence
• Work type: Master's thesis/paper
• Organization: BF - Biotechnical Faculty
• Year: 2019
• PID: 20.500.12556/RUL-110245
• COBISS.SI-ID: 5330767
• Publication date in RUL: 13.09.2019

LOVŠIN, Žana, 2019, Konjugativni plazmidi in filogenetske skupine sevov bakterije Escherichia coli, izoliranih iz perutnine [online]. Master’s thesis. [Accessed 23 March 2025]. Retrieved from: https://repozitorij.uni-lj.si/IzpisGradiva.php?lang=eng&id=110245

Secondary language

• Language: English
• Title: Conjugative plasmids and phylo-groups of Escherichia coli strains from poultry

Abstract

We analysed 106 Escherichia coli isolates, retrieved from poultry farm samples from different parts of Slovenia and isolated at the Veterinary faculty of the University of Ljubljana. In 35,85 % of isolates we confirmed the presence of conjugative plasmids that confer phenotypic resistance against ampicillin, tetracycline, cefotaxime, chloramphenicol or trimethoprim. None of the isolates was resistant against ciprofloxacin or colistin. While the majority of the conjugative plasmids were detected in isolates from air, feces and food in stalls, a lower proportion was found in isolates from flocks with high mortality due to colibacillosis. For transconjugant confirmation we used different molecular methods, including phylogenetic grouping and ERIC-PCR profiles of donors and transconjugants. Additionally, grouping of E. coli into phylogenetic groups according to the original and revised protocol was compared. Some isolates from previous group A1 thus were reassigned to group C, allowing a better distinction between donors and transconjugants. Together, 26.42 % of isolates were reassigned. The prevalence of selected virulence factor genes encoding adhesins, iron uptake systems, immune evasion factors and toxins was analysed in order to find possible links to phylogenetic group classification. Isolates with more or less virulence factor genes belonged to phylogenetic group B2 and A, respectively. Isolates from group F were predominantly retrieved from flocks with colibacillosis and have multiple virulence factors genes, including at least three iron acquisition systems. Interestingly, phylogenetic group F isolates were the only from which resistance determinants could not be transferred by conjugation.

• Keywords: biology, Escherichia coli, poultry, conjugative plasmids, resistances, phylogenetic groups, virulence factors