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Opis: Background : Campylobacter spp. are a major cause of bacterial food-borne diarrhoeal disease. This mainly arises through contamination of meat products during processing. For infection, Campylobacter spp. must adhere to epithelial cells of the mucus layer, survive conditions of the gastrointestinal tract, and colonise the intestine of the host. Addition of probiotic bacteria might promote competitive a dhesion to epithelial cells, consequently reducing Campylobacter jejuni colonisation. Effect of Lactobacillus spp. (PCS20, PCS22, PCS25, LGG, PCK9) on C. jejuni adhesion, invasion and translocation in pig (PSI cl.1) and chicken (B1OXI) small-intestine cell lines, as well as pig enterocytes (CLAB) was investigated. Results : Overall, in competitive adhesion assays with PSI cl.1 and CLAB cell monolayers, the addition of Lactobacillus spp. reduced C. jejuni adherence to the cell surface, and negatively affected the C. jejuni invasion. Interestingly, Lactobacillus spp. significantly impaired C. jejuni adhesion in three-dimensional functional PSI cl.1 and B1OXI cell models. Also, C. jejuni did not translocate across PSI cl.1 and B1OXI cell monolayers when co-incubated with probiotics. Among selected probiotics, Lactobacillus rhamnosus LGG was the strain that reduced adhesion efficacy of C. jejuni most significantly under co-culture conditions. Conclusion : The addition of Lactobacillus spp. to feed additives in livestock nutrition might be an effective novel strategy that targets Campylobacter adhesion to epithelial cells, and thus prevents colonisation, reduces the transmission, and finally lowers the incidence of human campylobacteriosis.
Ključne besede: Campylobacter jejuni, Lactobacillus spp., chicken and pig cell line, adhesion, invasion, translocation
Objavljeno v DKUM: 06.02.2025; Ogledov: 0; Prenosov: 2
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Opis: Izrabljen substrat za gobe (IGS) je stranski proizvod gojenja gob, ki sestoji iz raznovrstnih organskih materialov. Po nekaj sezonah rabe se substrat izčrpa in praviloma velja za odpadek, vendar sodobne raziskave nakazujejo številne koristne možnosti uporabe izrabljenega gobjega substrata. V projektni raziskavi se je IGS uporabljal kot organsko gnojilo na treh različnih lokacijah v ekološki, integrirani in biodinamični pridelavi paradižnika v rastlinjakih. V vsaki od pridelav se je v triplikatih testiralo gnojenje z SMS, standardno gnojenje (S), SMS+S in kontrola brez gnojenja. V sklopu magistrskega dela smo na obravnavanih lokacijah jemali vzorce zemlje v vseh letnih časih, v vzorcih pa smo analizirali aktivnost encimov N-acetil-glukozaminidaza (NAG), fosfataza (PHOS), beta-glukozidaza (β0GLU), arilsulfataza (ARS), ureaza (URE), arilamidaza (ARN), alkalna fosfataza (PAK) in kisla fosfataza (PAC) po standardu ISO 20130:2018- Kakovost tal - Merjenje encimske aktivnosti v vzorcih tal s kolorimetričnimi substrati na mikrotitrski plošči. Primerjali smo razlike v encimski aktivnosti med posameznimi letnimi časi ter med različnimi načini gnojenja. Rezultati so pokazali, da različni letni časi vplivajo na aktivnost encimov v tleh, medtem ko dodatek gobjega substrata kot gnojila ne povzroči nujno povišanja encimske aktivnosti.
Ključne besede: talni encimi, izrabljen gobji substrat, aktivnost, gnojenje, kmetijstvo
Objavljeno v DKUM: 03.09.2024; Ogledov: 52; Prenosov: 47
Celotno besedilo (3,58 MB)

Opis: The maintenance of a healthy status depends on the coexistence between the host organism and the microbiota. Early studies have already focused on the nutritional properties of probiotics, which may also contribute to the structural changes in the gut microbiota, thereby affecting host metabolism and homeostasis. Maintaining homeostasis in the body is therefore crucial and is reflected at all levels, including that of glucose, a simple sugar molecule that is an essential fuel for normal cellular function. Despite numerous clinical studies that have shown the effect of various probiotics on glucose and its homeostasis, knowledge about the exact function of their mechanism is still scarce. The aim of our review was to select in vivo and in vitro studies in English published in the last eleven years dealing with the effects of probiotics on glucose metabolism and its homeostasis. In this context, diverse probiotic effects at different organ levels were highlighted, summarizing their potential mechanisms to influence glucose metabolism and its homeostasis. Variations in results due to different methodological approaches were discussed, as well as limitations, especially in in vivo studies. Further studies on the interactions between probiotics, host microorganisms and their immunity are needed.
Ključne besede: probiotic, mechanism, glucose, metabolism, homeostasis
Objavljeno v DKUM: 28.06.2024; Ogledov: 415; Prenosov: 15
Celotno besedilo (2,58 MB)
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Opis: The antioxidant activity (AA) of hop extracts obtained from different hop genotypes (n = 14) was studied. For comparison, the purified β-acids-rich fraction and α-acids-with-β-acids-rich fraction were also used to test the antioxidative potential. The AA of purified hydroacetonic hop extracts was investigated using the Ferric Reducing Ability of Plasma (FRAP), Oxygen Radical Absorption Capacity (ORAC) and Intracellular Antioxidant (IA) methods. The FRAP values in different hop genotypes ranged between 63.5 and 101.6 μmol Trolox equivalent (TE)/g dry weight (DW), the ORAC values ranged between 1069 and 1910 μmol TE/g DW and IA potential values ranged between 52.7 and 118.0 mmol TE/g DW. Significant differences in AA between hop genotypes were observed with all three methods. AAs were determined using three different methods, which did not highly correlate with each other. We also did not find significant correlations between AA and different chemical components, which applies both to AA determined using individual methods as well as the total AA. Based on this fact, we assume that the synergistic or antagonistic effects between hop compounds have a more pronounced effect on AA than the presence and quantity of individual hop compounds.
Ključne besede: hop, antioxidant activity, FRAP, ORAC, intracellular antioxidative potential, genotypes
Objavljeno v DKUM: 20.03.2024; Ogledov: 271; Prenosov: 16
Celotno besedilo (1,23 MB)
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Opis: Increasing antimicrobial resistance has caused a great interest in natural products as alternatives or potentiators of antibiotics. The objective of this study was to isolate individual tannins from crude chestnut extract as well as to determine the influence of both crude extracts (tannic acid extract, chestnut extract) and individual pure tannins (gallic acid, vescalin, vescalagin, castalin, castalagin) on the growth of Gram-positive Staphylococcus aureus bacteria. Their antibacterial activity was monitored by measuring the minimum inhibitory concentration (MIC) and minimum bactericidal concentration (MBC) as well as the duration of the lag phase, growth rate and generation time. The effect of growth medium strength on the MIC of different tannins was also investigated. Bacterial growth was followed spectrophotometrically, and MIC values were determined by the microdilution method. The MIC values of various isolated compounds allowed us to determine the bioactive compounds and their contribution to antimicrobial activity. It was found that MIC values increase with increasing growth medium strength and that the lag phase lengthens with increasing tannin concentrations, while the growth rates decrease. Comparing the results of the two studies, the antimicrobial activity of tannins against S. aureus was not as pronounced as in the case of E. coli, which may indicate that a different mechanism of action is responsible for the antimicrobial effects of tannins on Gram-positive than on Gram-negative bacteria, or that a different mechanism is more pronounced.
Ključne besede: tannins, antibacterial activity, MIC, MBC, Staphylococcus aureus, lag phase, generation time
Objavljeno v DKUM: 20.02.2024; Ogledov: 363; Prenosov: 71
Celotno besedilo (1,19 MB)
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