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undergraduate thesis
Utjecaj citokalasina D na ulazak bakterija Legionella pneumophila i Francisella novicida u amebu Dictyostelium discoideum

Valerija Nora (2016)
Metadata
TitleUtjecaj citokalasina D na ulazak bakterija Legionella pneumophila i Francisella novicida u amebu Dictyostelium discoideum
AuthorValerija Nora
Mentor(s)Marina Šantić (thesis advisor)
Abstract
Legionella pneumophila je gram-negativna aerobna bakterija koja pripada porodici Legionelaceae. Legionele su rasprostranjene posvuda u prirodi, a osobito su rasprostranjene u vodenom okolišu. Sposobnost preživljavanja u protozoama im omogućuje preživljavanje u nepovoljnim uvjetima. L. pneumophila uzrokuje blaži febrilni oblik bolesti, pontijačku groznicu te teži oblik bolesti, atipičnu pneumoniju koja se po američkim legionarima naziva legionarska bolest. Francisella tularensis je gram-negativna i asporogena bakterija koja pripada porodici Franciselaceae. U porodicu Franciselaceae pripada samo rod Francisella koji uključuje sljedeće vrste: F. tularensis, F. hispaniensis, F. philomiragia, F. noatunensis i F. novicida.F. tularensis dijeli se na tri podvrste F. tularensis subsp. tularensis (tip A), F. tularensis subsp. holarctica (tip B) i F. tularensis subsp. mediasiatica. F. tularensis subsp. tularensis (tip A) i F. tularensis subsp. holarctica (tip B) uzrokuju bolest kod čovjeka, dok se F. tularensis subsp. mediasiatica pokazalamanje virulentnom. F. tularensis subsp. tularensis je visoko virulentna bakterija,a zbog lakog prenošenja zrakom i vrlo niske infektivne doze, smatra se i potencijalnim biološkim oružjem.Donedavno se četvrtom podvrstom smatrala i novicida, ali ona je ipak svrstana u zasebnu vrstu. F. novicida je avirulentna za čovjeka,a uzrokuje bolest samo kod imunokompromitiranih.Cilj ovog rada bio je pratiti mehanizam ulaska unutarstaničnih bakterija L. pneumophila i F. novicida u D. discoideum. Također, željeli smo utvrditi ovisi li učinak citokalasina D o njegovoj koncentraciji. Citokalasin D je alkaloid gljiva koji depolimerizira aktinski filament na način da se veže za jedan njegov kraj i tako blokira njegov daljnji rast pa se zbog toga naziva inhibitor polimerizacije aktinskih niti.Kinetika rasta i razmnožavanja bakterija L. pneumophila i F. novicida u amebama D. discoideum tretiranim citokalasinom D praćena je u periodima od 1, 5, 24 i 48 sati nakon infekcije. Broj unutarstaničnih bakterija određivan je nasađivanjem desetorostrukih razrijeđenja na BCYE podlogu.Naši rezultati pokazuju da se bakterije F. novicida i L. pneumophila uspješno razmnožavaju i preživljavaju u amebi D. discoideum. Broj bakterija F. novicida u amebama doseže maksimum u periodu od 48 sati nakon infekcije. Međutim, rezultati su pokazali kako dodatak citokalasina D, kao ni njegova koncentracija, nema utjecaj na rast bakterija F. novicida i L. pneumophilau amebi D. discoideum.
KeywordsF. novicida L. pneumophila cytochalasin D D. discoideum
Committee MembersIvana Gobin (committee chairperson)
Darinka Vučković (committee member)
Marina Šantić (committee member)
GranterSveučilište u Rijeci
Medicinski fakultet
Lower level organizational unitsKatedra za mikrobiologiju i parazitologiju
PlaceRijeka
StateCroatia
Scientific field, discipline, subdisciplineBIOMEDICINE AND HEALTHCARE
Clinical Medical Sciences
Medical Microbiology
Study programme typeuniversity
Study levelundergraduate
Study programmeStudy of Sanitary Engineering
Academic title abbreviationuniv. bacc. sanit. ing.
Genreundergraduate thesis
Language Croatian
Defense date2016-09-07
Parallel abstract (English)
Legionella pneumophila is a gram-negative aerobic bacteria which belong to the family Legionelaceae. Legionella is ubiquitous in the nature, and is particularly widespread in the aquatic environment. The ability to survive in protozoa allows the bacterium to survive in unfavorable conditions. L. pneumophila causes a milder form of febrile disease, pontiac fever and severe form of the disease, atypical pneumonia, which is called legionnaires' disease. Francisella tularensis is a gram-negative bacteria which belongs to the family Franciselaceae. The family Franciselaceae contains only genus Francisella which includes the following subspecies: F. tularensis, F. hispaniensis, F. philomiragia, F. noatunensis and F. novicida.F. tularensis is divided into three subspecies of F. tularensis subsp. tularensis (type A), F. tularensis subsp. holarctica (type B) and F. tularensis subsp. mediastatica. F. tularensis subsp. tularensis (type A) and F. tularensis subsp. holarctica (type B) cause disease in humans, while F. tularensis subsp. mediastatica showed to be less virulent. F. tularensis subsp. tularensis is avery virulent bacterium, and because of a very low infection dose and airbone transmission, is considered a potential biological weapon.Until recently, the fourth subspecies considered novicida, but it is still classified as a separate species. F. novicida is the avirulent bacteria that causes disease only in immunocompromised. The aim of this study was to monitor the entry and growth of bacteria F. novicida and L. pneumophila in Dictyostelium discoideum cells after treatment with cytochalasin D. Also, we wanted to determine whether the concentration of cytochalasin D has an influence on number of intracellular bacteria. Cytochalasin D, an alkaloid fungi depolymerize actin filaments in a way that it binds to one end and thereby blocks its further growth and thus is referred to as a polymerization inhibitor of actin filaments. The kinetics of growth and reproduction of bacteria L. pneumophila and F. novicida in amoeba D. discoideum treated with cytochalasin D is followed by a period of 1, 5, 24 and 48 hours after infection. Number of intracellular bacteria was determined by seeding tenfold dilutions on BCYE surface.Our results show that the bacteria F. novicida and L. pneumophila successfully survive and replicate in amoeba D. discoideum. The number of bacteria F. novicida within the amoeba reaches maximum in the period of 48 hours after infection. However, the results showed that the addition of cytochalasin D, as well as its concentration, has no impact on the growth of F. novicida and L. pneumophila in amoeba D. discoideum.
Parallel keywords (Croatian)F. novicida L. pneumophila citokalasin D D. discoideum
Resource typetext
Access conditionAccess restricted to higher education institution's students and staff
Terms of usehttp://rightsstatements.org/vocab/InC/1.0/
URN:NBNhttps://urn.nsk.hr/urn:nbn:hr:184:334553
CommitterBosa Licul