|
|
Biofilm formation in probiotic cultures and its application in pharmacy
Ryšávka, Petr ; Obruča, Stanislav (referee) ; Vorlová, Lenka (referee) ; Márová, Ivana (advisor)
The work was comprehensively focused on the development of adhesive forms of probiotics in the form of a biofilm on combined carriers with a prebiotic component. The second part dealed with the influence of food on the multiplication and survival of selected types of probiotic bacteria. Subsequently, the effect of individualized probiotic supplements on changes in the human intestinal microbiome was monitored. Suitable adherent probiotic strains for biofilm formation were selected and tested. Methods have been introduced and different variants of carriers for culturing and binding bacteria have been tested. In vitro experiments verified the stability of biofilm stucture and its resistance to low pH, bile and antibiotics in comparison with the planktonic cell form. The antimicrobial effect of probiotic strains in the form of a biofilm was studied. The cultivation of the multispecies biofilm on the combined carrier was optimized and the stability of the biofilm and the final viability of probiotic bacteria were confirmed. Furthermore, the influence of various foods and beverages on the viability of probiotic bacteria was evaluated with emphasis on the simulation of passage through the gastrointestinal tract. Both models, solutions with standardised concentrations of alcohol, sugar, salts, proteins or different pH and different types of real foods and beverages were tested. The effect of food and beverages was tested on monocultures of Lactobacillus acidophilus, Bifidobacterium breve and on probiotic capsules containing a mixed culture of probiotic microorganisms. The survival of probiotics in various food matrices in the simulated gastrointestinal tract was quantitatively different. We managed to define foods suitable for supporting the multiplication of probiotic bacteria. A separate part of the work was focused on the targeted modulation of the intestinal microbiome by individualized probiotics that were prepared on the basis of molecular biological analyzes of the intestinal microbiome aimed at detecting the percentage of lactobacilli, bifidobacteria and phylum Firmicutes and Bacteroidetes. Personalized probiotic supplementation confirmed the positive effect of this approach on microbiome changes, especially on the increase of the content of lactobacilli, bifidobacteria and the overall diversity of the microbiome.
|
|
|
Výskyt antimikrobiální rezistence u streptokoků (převážně beta-hemolytických) z ran pacientů
Kuropata, Daniel
Recently, a frequent occurrence of antibiotic resistance has been observed, and is still increasing. Therefore, it is important to constantly monitor this resistance, which was the aim of this work for Streptococcus genera. The literature review is focused on the selected species of streptococci (S. agalactiae, S. dysga-lactiae subsp. equisimilis, S. pyogenes, S. mitis and S. oralis), antibiotics, including their mechanism of action, and antibiotic resistance with an emphasis on its emergence, spread, mechanisms, determining genes and the risks it presents. In the experimental part, the occurrence of resistance in streptococci (especially beta-haemolytic) isolated from patients’ wounds at the Trauma Hospital in Brno was monitored. For this purpose, determination of the minimum inhibitory concentration (MIC), analysis of the resistance phenotype to macrolides, lincosamides and streptogramin B (MLS) using the D-test and resistance gene screening by polymerase chain reaction (PCR) were used. Among the 31 clinical isolates the prevalence of resistance to cotrimoxazole (96.8%), ciprofloxacin (71%), tetracycline (29%), erythromycin (25.5%), clidamycin (16 .1%), ampicillin (3.2%) and oxacillin (3.2%) was found by using MIC. Resistance to chloramphenicol, gentamicin, vancomycin, teicoplanin, linezolid, tigecycline and nitrofurantoin has not been detected. The D-test was performed with erythromycin-resistant isolates. The constitutive (cMLS) phenotype was detected in 62.5% of erythromycin-resistant isolates, inducible (iMLS) in 25% and M phenotype in 12.5%. The PCR method confirmed the presence of selected resistance genes, namely ermA (16.1%), ermB (6.5%), mefA (3.2%), tetO (3.2%), tetM (25.8%) and intTn (32.3%). This study demonstrated that all streptococcal isolates from patients’ wounds are resistant to some of the tested antibiotics. Moreover, multiresistance was detected in some isolates.
|
|
|
Study of phosphorylation of inorganic pyrophosphatase from Streptococcus pneumoniae
Štechová, Michaela ; Doubravová, Linda (advisor) ; Svobodová, Jaroslava (referee)
The human patogen Streptococcus pneumoniae encodes a single copy of eukaryotic-like Ser/Thr protein kinase StkP. StkP regulates virulence, competence, stress resistence, gene expression and plays a role in the regulation of cell division cycle. Analysis of phosphoproteome maps of the wild type and stkP mutant strain of S. pneumoniae showed that in vivo StkP phosphorylates several putative substrates including Mn-dependent inorganic pyrophosphatase PpaC. Mass spectrometry analysis identified two phosphorylation sites in an active site of the protein. Pyrophosphatases are essential enzymes that catalyze hydrolysis of inorganic pyrophosphate produced during various biosynthetic reactions that utilize ATP. Changes in pyrophosphatase activity have been described to have global effects on cell metabolism, growth and division of bacteria. The aim of this thesis was to investigate the phosphorylation of inorganic pyrophosphatase PpaC in S. pneumoniae. Gene ppaC was cloned, expressed in E. coli and protein was purified via affinity chromatography. Phosphorylation of PpaC by StkP was examined in a kinase assay but we did not confirm that PpaC is a direct substrate of StkP in vitro. Further we prepared a set of mutants in ppaC gene. We replaced two presumable phosphoaminoacids identified by mass-spectrometry with...
|
|
|
Biofilm formation in probiotic cultures and its application in pharmacy
Ryšávka, Petr ; Obruča, Stanislav (referee) ; Vorlová, Lenka (referee) ; Márová, Ivana (advisor)
The work was comprehensively focused on the development of adhesive forms of probiotics in the form of a biofilm on combined carriers with a prebiotic component. The second part dealed with the influence of food on the multiplication and survival of selected types of probiotic bacteria. Subsequently, the effect of individualized probiotic supplements on changes in the human intestinal microbiome was monitored. Suitable adherent probiotic strains for biofilm formation were selected and tested. Methods have been introduced and different variants of carriers for culturing and binding bacteria have been tested. In vitro experiments verified the stability of biofilm stucture and its resistance to low pH, bile and antibiotics in comparison with the planktonic cell form. The antimicrobial effect of probiotic strains in the form of a biofilm was studied. The cultivation of the multispecies biofilm on the combined carrier was optimized and the stability of the biofilm and the final viability of probiotic bacteria were confirmed. Furthermore, the influence of various foods and beverages on the viability of probiotic bacteria was evaluated with emphasis on the simulation of passage through the gastrointestinal tract. Both models, solutions with standardised concentrations of alcohol, sugar, salts, proteins or different pH and different types of real foods and beverages were tested. The effect of food and beverages was tested on monocultures of Lactobacillus acidophilus, Bifidobacterium breve and on probiotic capsules containing a mixed culture of probiotic microorganisms. The survival of probiotics in various food matrices in the simulated gastrointestinal tract was quantitatively different. We managed to define foods suitable for supporting the multiplication of probiotic bacteria. A separate part of the work was focused on the targeted modulation of the intestinal microbiome by individualized probiotics that were prepared on the basis of molecular biological analyzes of the intestinal microbiome aimed at detecting the percentage of lactobacilli, bifidobacteria and phylum Firmicutes and Bacteroidetes. Personalized probiotic supplementation confirmed the positive effect of this approach on microbiome changes, especially on the increase of the content of lactobacilli, bifidobacteria and the overall diversity of the microbiome.
|
|
|
Study of phosphorylation of inorganic pyrophosphatase from Streptococcus pneumoniae
Štechová, Michaela ; Svobodová, Jaroslava (referee) ; Doubravová, Linda (advisor)
The human patogen Streptococcus pneumoniae encodes a single copy of eukaryotic-like Ser/Thr protein kinase StkP. StkP regulates virulence, competence, stress resistence, gene expression and plays a role in the regulation of cell division cycle. Analysis of phosphoproteome maps of the wild type and stkP mutant strain of S. pneumoniae showed that in vivo StkP phosphorylates several putative substrates including Mn-dependent inorganic pyrophosphatase PpaC. Mass spectrometry analysis identified two phosphorylation sites in an active site of the protein. Pyrophosphatases are essential enzymes that catalyze hydrolysis of inorganic pyrophosphate produced during various biosynthetic reactions that utilize ATP. Changes in pyrophosphatase activity have been described to have global effects on cell metabolism, growth and division of bacteria. The aim of this thesis was to investigate the phosphorylation of inorganic pyrophosphatase PpaC in S. pneumoniae. Gene ppaC was cloned, expressed in E. coli and protein was purified via affinity chromatography. Phosphorylation of PpaC by StkP was examined in a kinase assay but we did not confirm that PpaC is a direct substrate of StkP in vitro. Further we prepared a set of mutants in ppaC gene. We replaced two presumable phosphoaminoacids identified by mass-spectrometry with...
|
guest ::
