Ugotavljanje intenzivnosti pritrjevanja bakterij vrste Legionella pneumophila na površine materialov za vodovodne napeljave : doktorska disertacija

Oder, Martina (author), Godič Torkar, Karmen (mentor), Kompare, Boris (comentor)

V raziskavi smo ţeleli preučiti, kako na oprijem bakterijskih celic Legionella pneumophila subsp. pneumophila ATCC 33152 vplivajo lastnosti različnih vrst materialov, kot so njihova hrapavost, hidrofobnost in naboj, vpliv različnih temperaturnih pogojev, striţnih sil in prisotnost razkuţila dikloroizocianurne kisline ter mehčala natrijevega polifosfata. V prvem delu raziskave smo ugotavljali oprijem bakterijskih celic na steklene borosilikatne ploščice različnih hrapavosti, v drugem delu pa na površine materialov, ki se najpogosteje uporabljajo za vodovodne napeljave v zgradbah. Ti materiali so imeli različno sestavo, hrapavost in mejni kot. Za ugotavljanje intenzivnosti oprijema bakterij na površine smo uporabili spektrofotometrično metodo merjenja optične gostote barvila kristal vijolično, ki se sprosti iz predhodno obarvanih bakterijskih celic, oprijetih na testno površino. V prvem delu študije smo ugotovili, da hrapavost materiala vpliva na oprijem bakterijskih celic, saj je bil oprijem na bolj hrapavih steklenih ploščicah večji. Pri študiju oprijema na materiale, ki se najpogosteje uporabljajo za vodovodne inštalacije, pa so rezultati pokazali, da oprijem na površine ni bil odvisen samo od hrapavosti materiala, ampak tudi od ostalih lastnosti, saj oprijem na najmanj hrapavem materialu ni bil najmanjši. Testna bakterija se je najintenzivneje oprijela na pocinkane cevi, najmanj pa na cevi iz polipropilena. Na oprijem bakterije je vplivala tudi temperatura inkubacije, saj je bil največji pri temperaturi 36 ºC, najmanjši pa pri temperaturi 15 ºC. Temperatura inkubacije 15 ºC je na bakterijske celice delovala bakteriostatično, temperatura 55 ºC pa baktericidno.

• Language: Slovenian
• Keywords: sanitarno inženirstvo, gradbeništvo, doktorske disertacije, Legionella pneumophila, bakterijska adhezija, biofilmi
• Work type: Dissertation
• Typology: 2.08 - Doctoral Dissertation
• Organization: FGG - Faculty of Civil and Geodetic Engineering
• Publisher: [M. Oder]
• Year: 2015
• Number of pages: XXIII, 135 str., [4] str. pril.
• PID: 20.500.12556/RUL-80157
• UDC: 628.19:628.1.032(043)
• URN: URN:NBN:SI:DOC-2AZTI018
• COBISS.SI-ID: 4968043
• Publication date in RUL: 28.01.2016

ODER, Martina, 2015, Ugotavljanje intenzivnosti pritrjevanja bakterij vrste Legionella pneumophila na površine materialov za vodovodne napeljave : doktorska disertacija [online]. Doctoral dissertation. M. Oder. [Accessed 5 April 2025]. Retrieved from: https://repozitorij.uni-lj.si/IzpisGradiva.php?lang=eng&id=80157

Secondary language

• Language: English
• Title: Determination of the intensity of bacteria Legionella pneumophila attachment to the surface materials for plumbing : doctoral thesis

Abstract

In this study we wanted to examine how the adhesion of Legionella pneumophila subsp. pneumophila ATCC 33152 bacterial cells is affected by the properties of various types of materials, such as roughness, hydrophobicity and charge, and how the bacteria are affected by different temperature conditions, shear forces and the presence of disinfectants dichloroisocyanuric acid and water softeners sodium polyphosphate. In the first part of the study we determined the adhesion of bacterial cells on borosilicate glass coupons of different roughness, while in the second part adhesion on the surface of materials that are most commonly used for plumbing and ventilation sistems in buildings. The materials differed in composition, roughness and contact angle. The adhesion of the bacteria to different surfaces was determined by the spectrophotometric measurement of the optical density of crystal violet dye released from the stained bacterial cells adhering to the test surface. In the first part of the study, it was established that the roughness of the material affects the adhesion of bacterial cells, as adhesion was higher on rougher glass coupons. The results of the study of bacterial adhesion to materials most commonly used in plumbing showed that adhesion not only depended on the roughness of the material but also on its other properties, as adhesion was not the lowest on the smoothest material. The test bacteria adhered the most firmly to galvanised pipes and the least firmly to polypropylene pipes. Bacteria adhesion was also affected by the incubation temperature, because adhesion was the highest at a temperature of 36 ° C and the lowest at a temperature of 15 ° C. The results show that incubation temperature of 15 ° C is bacteriostatic and temperature of 55 ° C is bactericidal.

• Keywords: sanitary engineering, civil engineering, doctoral thesis, Legionella pneumophila, bacterial adhesion, biofilms