Virulentni čimbenici bakterije Enterococcus faecalis iz različitih izolacijskih izvora

master's thesis

• Title (english): Virulence factors of the bacterium Enterococcus faecalis from different isolation sources
• Author: Željka Novosel
• Mentor: Ivan Kosalec (mentor)
• Committee member: Ivan Kosalec (predsjednik povjerenstva)
• Committee member: Petra Turčić (član povjerenstva)
• Committee member: Josipa Vlainić (član povjerenstva)
• Granter: University of Zagreb; Faculty of Pharmacy and Biochemistry; (Department of microbiology); Zagreb
• Defense date and country: 2023-07-11, Croatia
• Scientific / art field, discipline and subdiscipline: BIOMEDICINE AND HEALTHCARE; Pharmacy; Pharmacy

Abstract

Bakterija Enterococcus faecalis je oportunistički patogen, poznata po komenzalističkom životu kao dio mikrobiote
različitih organskih sustava, a nalazi se i u okolišu. Uzrokuje infekcije urinarnog sustava, inficira kože i rane, a također
je specifična kao uzročnik endokarditisa. Sadrži mnoge virulentne čimbenike, a u ovom radu su detaljnije obrađeni
hidrofobnost stanične površine, sposobnost stvaranja biofilma, β-hemolitička aktivnost te osjetljivost na vankomicin.
Cilj diplomskog rada je bio utvrditi postoje li značajne razlike u uvjetima in vitro u virulenciji sojeva E. faecalis
izoliranih iz bolnice, hrane i otpadnih voda nakon statističke obrade rezultata. Istraživanjem hidrofobnosti stanične
površine zaključuje se da sojevi izolirani iz hrane imaju najveću hidrofobnost, dok između bolničkih izolata i onih iz
otpadnih voda nije bilo značajne razlike. Prema metodi iz rada Stępień-Pyśniak (2019), sposobnost stvaranja biofilma
je podijeljena u četiri kategorije te su sojevi iz bolničkog izvora najjači produktori biofilma, zatim sojevi iz hrane i
sojevi iz otpadnih voda kao najslabiji produktori biofilma. Ako se gleda sposobnost stvaranja biofilma samo prema
izmjerenoj optičkoj gustoći sojeva, najjači produktori biofilma su sojevi iz hrane potom iz otpadnih voda i konačno
bolnički izolati. Hemoliza je utvrđena u 20,00% sojeva iz bolničkog izvora, 16,67% iz hrane te 26,67% iz otpadnih
voda pri čemu Bonfferonijev test ukazuje da razlike između rezultata različitih sojeva nisu statistički značajne. Od
ukupno 30 sojeva iz svakog izvora, rezistenciju na vankomicin iz bolničkog izvora je pokazalo 10,00%, iz hrane 3,33%
i iz otpadnih voda 20,00%. Može se zaključiti da se nakon provedenih ispitivanja nulta hipoteza pokazala točnom kod
svih virulentnih čimbenika osim hemolize.

Abstract (english)

The bacterium Enterococcus faecalis is an opportunistic pathogen known for its commensal life as part of the microbiota
of various organic systems and it can also be found in the environment. It causes infections of the urinary system, infects
skin and wounds, and is also a specific cause of endocarditis. It holds many virulent factors, of which the hydrophobicity
of the cell surface, the ability to form biofilm, β-hemolytic activity and susceptibility to vancomycin are discussed in
more detail in this paper. The aim of the thesis was to determine whether there are significant differences in in vitro
conditions the virulence of E. faecalis strains isolated from the hospital, food and wastewater after statistical data
processing. By investigating the hydrophobicity of the cell surface, it was concluded that the strains isolated from food
have the highest hydrophobicity, while there was no significant difference between hospital isolates and those from
wastewater. According to the method from the work of Stępień-Pyśniak (2019), the ability to form biofilm is divided
into four categories and those isolated from a hospital source are the strongest biofilm producers followed by strains
from food and strains from wastewater as the weakest biofilm producers. If the ability to form a biofilm is viewed only
according to the measured optical density of the strains, the strongest biofilm producers are strains isolated from food,
followed by isolates from wastewater and finally hospital isolates. Hemolysis was shown by 20,00% of strains from a
hospital source, 16,67% from food and 26,67% from wastewater, while the Bonfferoni test indicates that the differences
between the results of different strains are not statistically significant. Out of a total of thirty strains from each source,
10,00% showed resistance to vancomycin from a hospital source, 3,33% from food and 20,00% from wastewater. It can
be concluded that after the conducted tests, the null hypothesis proved to be correct for all virulence factors except
hemolytic activity.

• Keywords: Enterococcus faecalis; hidrofobnost stanične površine; biofilm; hemoliza; rezistencija; vankomicin
• Keywords (english): Enterococcus faecalis; cell surface hydrophobicity; biofilm; hemolysis; resistancet; vancomycin
• Language: croatian
• URN:NBN: urn:nbn:hr:163:911202
• Study programme: Title: Pharmacy; Study programme type: university; Study level: integrated undergraduate and graduate; Academic / professional title: magistar/magistra farmacije (magistar/magistra farmacije)
• Type of resource: Text
• File origin: Born digital
• Access conditions: Open access
• Created on: 2023-11-16 13:02:24