Antimikrobno djelovanje i antibiotička rezistencija Peribacillus spp. izoliranih iz krške spilje

master's thesis

• Title (english): Antimicrobial activity and antibiotic resistance of Peribacillus spp. isolated from a karst cave
• Author: Lana Petković
• Mentor: Mirna Mrkonjić Fuka (mentor)
• Committee member: Mirna Mrkonjić Fuka (predsjednik povjerenstva)
• Committee member: Ivana Rajnović (član povjerenstva)
• Committee member: Kristina Krklec (član povjerenstva)
• Granter: University of Zagreb; Faculty of Agriculture; (Department of Microbiology); Zagreb
• Defense date and country: 2023-09-29, Croatia
• Scientific / art field, discipline and subdiscipline: BIOTECHNICAL SCIENCES; Agronomy

Abstract

Rod Peribacillus spada u porodicu Bacillaceae i tek je nedavno taksonomski odvojen od roda Bacillus. Budući da vrste roda Bacillus imaju značajnu ulogu u održavanju terestrijalnih ekosustava i velik potencijal primjene u poljoprivredi, pretpostavka je da pripadnici roda Peribacillus također imaju iste značajke. Cilj ovog istraživanja je ispitati potencijal vrsta roda Peribacillus izoliranih iz krške spilje za inhibiciju rasta humanih i biljnih patogena te istražiti ulogu ovih vrsta u širenju antibiotičke rezistencije u prirodi. Uzorci sedimenta i vode prikupljeni iz spilje u blizini naselja Konjevrate na području Šibensko-kninske županije korišteni su za izolaciju bakterija. Gram pozitivni izolati porasli na R2 agaru identificirani su MALDI-TOF uređajem. Nakon identifikacije testirana je njihova rezistencija na pet klasa antibiotika (karbapenemi, glikopeptidi, fluorokinoloni, makrolidi/linkozamidi i oksazolidinoni) disk difuzijskom metodom. Antimikrobno djelovanje ispitano je na osam potencijalno patogenih bakterija (E. coli, B. cereus, S. aureus, L. innocua, A. tumefaciens, E. amylovora, P. syringae i S. enterica) koje izazivaju bolesti ljudi i biljaka te na plijesan Botrytis cinerea. Od 75 izoliranih Gram pozitivnih izolata, 11,3 % je identificirano kao Peribacillus spp. Od 17 testiranih Peribacillus izolata, 35,3 % ih je rezistentno na makrolide/linkozamide, 5,9 % ih je rezistentno na fluorokinolone i oksazolidinone, dok niti jedan izolat nije pokazao rezistentnost na karbapeneme i glikopeptide. Peribacillus izolati nisu pokazali inhibitorno djelovanje prema patogenim bakterijama ili je ono vrlo slabo izraženo kod 5,9 % izolata. Jako inhibitorno djelovanje prema plijesni B. cinerea pokazalo je 47,1 % izolata.

Abstract (english)

The genus Peribacillus belongs to the family Bacillaceae and has recently been taxonomically separated from the genus Bacillus. Since species from the genus Bacillus play a significant role in maintaining terrestrial ecosystems and have great potential for agricultural applications, it is assumed that members of the Peribacillus genus also possess similar characteristics. The aim of this research is to investigate the potential of Peribacillus species isolated from a karst cave to inhibit the growth of human and plant pathogens and explore the role of these species in the spread of antibiotic resistance in nature. Sediment and water samples were collected from a cave near the settlement of Konjevrate in the Šibenik-Knin County and used for the isolation of bacteria. Gram-positive isolates that grew on R2 agar were identified using MALDI-TOF method. After identification, their resistance to five classes of antibiotics (carbapenems, glycopeptides, fluoroquinolones, macrolides/lincosamides and oxazolidinones) was tested by disk diffusion method. Antimicrobial activity was assessed against eight potentially pathogenic bacteria (E. coli, B. cereus, S. aureus, L. innocua, A. tumefaciens, E. amylovora, P. syringae and S. enterica) that cause diseases in humans and plants and on the phytopathogenic mold Botrytis cinerea. Out of 75 isolated Gram positive isolates, 11.3% were identified as Peribacillus spp. Out of 17 tested Peribacillus isolates, 35.3% were resistant to macrolides/lincosamides and 5.9% were resistant to fluoroquinolones and oxazolidinones, while none of the isolates showed resistance to carbapenems and glycopeptides. Peribacillus isolates showed no inhibitory activity against pathogenic bacteria or it was very weak in 5.9% of isolates. 47.1% of the isolates showed strong inhibitory activity against B. cinerea.

• Keywords: krška spilja; Peribacillus; antibiotička rezistencija; antimikrobno djelovanje
• Keywords (english): karst cave; Peribacillus; antibiotic resistance; antimicrobial activity
• Language: croatian
• URN:NBN: urn:nbn:hr:204:482399
• Study programme: Title: Agroecology; Study programme type: university; Study level: graduate; Academic / professional title: magistar/ magistra inženjer/inženjerka agroekologije (magistar/ magistra inženjer/inženjerka agroekologije)
• Type of resource: Text
• File origin: Born digital
• Access conditions: Open access
• Created on: 2023-11-08 11:36:14