Title Utjecaj ameba na broj bakterija u riječnoj vodi
Author Ivan Žagar
Mentor Marina Šantić (mentor)
Committee member Mateja Ožanič (predsjednik povjerenstva)
Committee member Dijana Detel (član povjerenstva)
Committee member Marina Šantić (član povjerenstva)
Committee member Valentina Marečić (član povjerenstva)
Granter University of Rijeka Faculty of Medicine (Department of Microbiology and Parasitology) Rijeka
Defense date and country 2021, Croatia
Scientific / art field, discipline and subdiscipline BIOMEDICINE AND HEALTHCARE Public Health and Health Care Health Ecology
Scientific / art field, discipline and subdiscipline BIOMEDICINE AND HEALTHCARE Clinical Medical Sciences Medical Microbiology
Abstract Ameba Acanthamoeba castellanii protozoa je koja pripada rodu Amoebae. Živi slobodno u prirodi; na tlu i u vodi. Većina vrsta su tzv. oportunistički patogeni, međutim neke vrste ipak mogu izazvati infekcije, posebice kod životinja i imunokomprimitiranih osoba. Acanthamoeba vrste opasne su zbog toga što mogu uzrokovati bolesti poput encefalitisa i amebnog keratitisa. Vrste Acanthamoeba domaćini su mnogobrojnim unutarstaničnim patogenima poput bakterija iz roda Legionella, Mycobacterium, Chlamydia i Francisella. Brojna istraživanja su pokazala da se Francisella razmnožava unutar ameba poput A. castellanii, te se stoga ova protozoa smatra važnom u prijenosu tularemije, posebice putem izvorskih i površinskih voda. Evolucijskim mehanizmima mnoge vrste bakterija su razvile sposobnosti da prežive unutar ameba. Mogućnost bakterije F. novicida da preživi i razmnožava se unutar ameba veoma je važna za njezin opstanak u vodenom okolišu. Cilj rada bio je ispitati utjecaj ameba A. castellanii na broj bakterija u riječnoj vodi Gorskog kotara – rijeci Čabranki. U uzorke su inokulirane određene koncentracije amebe A. castellanii te bakterije F. novicida. U jedan od uzoraka inokulirana je samo ameba A. castellanii, u drugi uzorak inokulirana je samo bakterija F. novicida, a u treći uzorak inokulirane su istovremeno i F. novicida i ameba A. castellanii. Broj bakterija između tri različite vrste uzoraka praćen je u periodu od 10 dana. Broj ameba A. castellanii utvrđen je pomoću Neubauer komorice pod invertnim mikroskopom, a broj ostalih bakterija utvrđen je metodom membranske filtracije te metodom nasađivanja na hranjive podloge. Nakon dobivenih rezultata za svaki od pojedine vrste uzoraka, rezultati su statistički obrađeni, a zatim međusobno uspoređeni. Zaključeno je da A. castellanii nema utjecaj na broj ostalih prethodno prisutnih bakterija u uzorcima. Rezultati istraživanja pokazuju da je amebama je pogodnije kada se nalaze samostalno u uzorku rijeke Čabranke, nego kada se nalaze zajedno s F. novicida, dok F. novicida bolje preživljava kada se u uzorku nalazi zajedno s amebama. Utvrđeno je i da bakterija najslabije preživljavaju u uzorku vode iz rijeke Čabranke u koji je dodana samo F. novicida. Prema Uredbi o kakvoći voda za kupanje rijeka Čabranka nije pokazala zadovoljavajući kriterij zbog prevelikog broja crijevnih enterokoka, međutim u rijeka Čabranka nije pogodan medij za rast C. perfringens, E. coli te fekalnih koliforma. Četvrtog dana nakon inokulacije (dan 4.) nije zabilježena prisutnost A. castellanii u nijednome od uzoraka.
Abstract (english) The amoeba Acanthamoeba castellanii is a protozoan belonging to the genus Amoebae. This
amoeba lives freely in nature; on land and in water. Most species are so-called opportunistic
pathogens, however, some species can still cause infections, especially in animals and
immunocompromised individuals. Acanthamoeba species are dangerous because they can
cause diseases such as encephalitis and amoebic keratitis. Acanthamoeba species host
numerous intracellular pathogens such as bacteria of the genera Legionella, Mycobacterium,
Chlamydia, and Francisella. Numerous studies have shown that Francisella reproduces
within amoebae such as A. castellanii, and therefore this protozoa is considered important in
the transmission of tularemia, especially through spring and surface waters. Through
evolutionary mechanisms, many species of bacteria have developed the ability to survive
within amoebae. The ability of F. novicida to survive and multiply within amoebae is very
important for its survival in the aquatic environment. The aim of this study was to examine
the influence of the amoeba Acanthamoeba castellanii on the number of bacteria in water
from river of Gorski kotar - the river Čabranka. Certain concentrations of amoeba A.
castellanii and bacteria F. novicida were added to the samples. To one of the samples was
inoculated only amoeba A. castellanii, to the second sample was inoculated only the
bacterium F. novicida, and to the third sample were inoculated both amoeba A. castellanii and
bacteria F. novicida. The number of bacteria between the three different types of samples was
monitored over a period of 10 days. The number of amoebae A. castellanii was determined
using a Neubauer chamber and invert microscope, and the number of other bacteria was
determined by membrane filtration and by planting on nutrient media. After the obtained
results for each of the individual types of samples, the results were statistically processed and
then compared with each other. It was concluded that the amoeba A. castellanii had no effect
on the number of other previously present bacteria in the samples. The results of the research
show that for amoebae is more suitable enviroment when they are found alone in a sample of
the river Čabranka, than when they are found together with the bacterium F. novicida, while
F. novicida survives better when is in the sample along with amoebae. It was also found that
the bacteria the least survives in a sample of water to which only F. novicida was previously
added. According to the document „Uredbi o kakvoći voda za kupanje“ , the river Čabranka
did not show a satisfactory criterion due to the excessive number of intestinal enterococci. the
The river Čabranka is not a suitable medium for the growth of bacteria such as C. perfringens,E. coli and fecal coliforms. On the fourth day after inoculation (day 4), the presence of A.
castellanii was not recorded in any of the samples.
Keywords
Acanthamoeba castellanii
Francisella novicida
rijeka Čabranka
vodeni okoliš
tularemija
unutarstanični život
Keywords (english)
Acanthamoeba castellanii
Francisella novicida
the river Čabranka
aquatic environment
tularemia
intracellular life
Language croatian
URN:NBN urn:nbn:hr:184:150757
Study programme Title: Study of Sanitary Engineering Study programme type: university Study level: graduate Academic / professional title: magistar/magistra sanitarnog inženjerstva (magistar/magistra sanitarnog inženjerstva)
Type of resource Text
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Created on 2021-06-17 08:37:59