Usporedba klasičnih mikrobioloških i molekularnih metoda u rutinskoj potvrdi bakterije Listeria monocytogenes iz tradicionalno mliječnih proizvoda s područja grada Zagreba

master's thesis

• Title (english): Comparasion of conventional and molecular methods for the routine confirmation of bacteria Listeria monocytogenes in milk products produced domestically from Zagreb
• Author: Kristina Kolarec
• Mentor: Jadranka Frece (mentor)
• Granter: University of Zagreb; Faculty of Food Technology and Biotechnology; (Department of Biochemical Engineering); (Laboratory for General Microbiology and Food Microbiology); Zagreb
• Defense date and country: 2009-11-05, Croatia
• Scientific / art field, discipline and subdiscipline: BIOTECHNICAL SCIENCES; Biotechnology

Abstract

Listeria monocytogenes je odavna prepoznata kao humani patogen, ali je tek ranih 80-tih godina prošlog stoljeća uočeno da je kontaminirana hrana glavni put prijenosa te bakterije iz okoliša u ljude. Svrha ovog rada bila je odrediti udovoljavaju li svježe sirovo mlijeko, sir i vrhnje koji se proizvode na tradi¬cionalan način u kućanstvu i slobodno prodaju na zagrebačkim tržnicama mikrobiološkim standardima za namirnice (NN 46/94, 20/01, 40/01). Posebna pažnja posvećena je istraživanju moguće prisutnosti bakterije L. monocytogenes u navedenim namirnicama, zbog njezine izrazite opasnosti po ljudsko zdravlje. Identifikacija je rađena klasičnim mikrobiološkim, biokemijskim (API- test) i molekularnim (PCR) metodama. Od 180 mliječnih proizvoda koji su testirani, 27,6 % su bili pozitivni na bakterije iz roda Listeria na PALCAM agaru. Od toga 21,3 % ih je bilo pozitivno na bakterije iz roda Listeria API- Listeria testom, a 17,3 % ih je potvrđeno da su pozitivni na L. monocytogenes PCR- metodom, umnažanjem hly gena (64bp). Pomoću PCR metode se mogu eliminirati lažno pozitivne i detektirati sve vrste L. monocytogenes prisutne u mliječnim proizvodima za razliku od konvencionalnih metoda korištenih u industriji.

Abstract (english)

Listeria monocytogenes has long been recognized as a human pathogen, but only the early 1980s of the past century it was noticed that contaminated food was a main way of bacterial transmission from the environment to humans. The purpose of this study was to determine whether the fresh raw milk, cheese and cream that are pro¬duced in the traditional manner at home and are free to sale on Zagreb markets, meet microbiologi¬cal requirements for foodstuffs (OG 46/94, 20/01, 40/01). Particular attention is given to research of bacteria L. monocytogenes possible presence in these foods, because of its exceptional hazards to human health. Identification was done with conventional microbiological, biochemical (API- test) and molecular methods. Of the 180 milk products samples tested, 27,6 % were presumptively positive for Listeria on PALCAM agar. Only 21,3 % of samples were confirmed to be positive for Listeria by API Listeria test, and 17,3 % were confirmed to be positive for L. monocytogenes by PCR amplification of the hly gene (64 bp). With PCR method, it' s possible to eliminate false possitive and detect presence of all species of L. monocytogenes in milk products, despite of conventional methods used in industry.

• Keywords: Listeria monocytogenes; izolacija; klasične mikrobiološke metode; PCR – metoda; API- Listeria test
• Keywords (english): Listeria monocytogenes; isolation; standard microbiological methods; PCR- method; API- Listeria test
• Language: croatian
• URN:NBN: urn:nbn:hr:159:119834
• Study programme: Title: Biotechnology; specializations in: Biochemical-Microbiology; Course: Biochemical-Microbiology; Study programme type: university; Study level: graduate; Academic / professional title: diplomirani inženjer biotehnologije; smjer biokemijsko-mikrobiološki (diplomirani inženjer biotehnologije; smjer biokemijsko-mikrobiološki)
• Type of resource: Text
• File origin: Born digital
• Access conditions: Access restricted to students and staff of home institution
• Created on: 2017-09-01 10:31:34