Fenotipska in genotipska opredelitev kliničnih izolatov bakterije Legionella pneumophila

Ražman, Nuša (author), Keše, Darja (mentor)

Bakterije rodu Legionella so znotrajcelični mikroorganizmi, ki pri ljudeh povzročajo pljučnico imenovano legionarska bolezen. V nalogi smo preučili podatke iz Laboratorijskega informacijskega sistema, o številu izvedenih testov, številu bolnikov, njihovi starosti in spolu. Ugotovili smo, da z leti število legioneloz in število testiranih vzorcev narašča. Rezultati so pokazali, da so okužbe pogostejše pri moških in pri starejših ljudeh. Razmerje med ženskami in moškimi je bilo 1 : 2,8, medtem, ko je bilo 74,3 % bolnikov starih med 41 in 80 let. S testom ELISA za dokaz legionelnega antigena v urinu (UAg) in s testom PCR je bilo hkrati testiranih 1.200 bolnikov, testa sta se ujemala v 98,3 %. V drugem delu naloge smo na podlagi fenotipizacije in genotipizacije želeli ugotoviti razširjenost posameznih legionelnih sevov v našem okolju. Klinične izolate smo serotipizirali z monoklonskimi protitelesi dresdenskega panela. Od 72 kliničnih izolatov je 68 izolatov sodilo v L. pneumophila sg. 1 in 85,3 % omenjenih izolatov je bilo MAb 3/1 pozitivnih. Najpogostejši fenotip je bil Allentown/France (47,1 %). S sekvenčno analizo smo dokazali tudi prisotnost 23 različnih sekvenčnih tipov, pri čemer je bil najpogostejši sekvenčni tip ST 1 (22,1 %). V primerjavi rezultatov tipizacij smo ugotovili, da ima lahko en sekvenčni tip več različnih fenotipov in obratno.

• Language: Slovenian
• Keywords: legionela, Legionella pneumophila, fenotipizacija, monoklonska protitelesa, genotipizacija
• Work type: Master's thesis/paper
• Typology: 2.09 - Master's Thesis
• Organization: BF - Biotechnical Faculty
• Publisher: [N. Ražman]
• Year: 2019
• PID: 20.500.12556/RUL-111581
• UDC: 579.253:579.841:577.2.083
• COBISS.SI-ID: 5105016
• Publication date in RUL: 04.10.2019

Secondary language

• Language: English
• Title: Phenotyping and genotyping of clinically important Legionella pneumophila isolates

Abstract

Legionella is an intracellular pathogen that is the causative agent of pneumonia termed Legionnaires' disease. In the first part our thesis, we studied the data from Laboratory information system. The number of cases of Legionnaires' disease has been on a rise. The results showed that male are more likely to be infected with Legionella. The male to female ratio was 2.8. Age is also a contributing factor as 74.3% of patients were 41 to 80 years old. 1,200 patient samples were tested with ELISA UAg test and PCR. The results of tests correlated in 98.3%. Secondly, we determinated the extent of different Legionella isolates in our environment. Clinical isolates were typed using monoclonal antibodies (MAbs) of Dresden panel. 68 of 72 collected clinical samples belonged to L. pneumophila serogroup 1. 85,3% of serogroup 1 isolates belonged to the MAb 3/1 positive soubgroup. The most frequently detected subgroup was Allentown/France (47.1%). Sequence-based typing detected 23 different sequence types, with the most represented ST 1 (22,1%). We concluded that the one sequence type can have various MAb subgroups and the contrary.

• Keywords: legionella, Legionella pneumophila, phenotyping, monoclonal antibodies, genotyping