|
|
One Health approach to understand emerging zoonotic pathogens in the Trichophyton benhamiae complex
Čmoková, Adéla ; Hubka, Vít (advisor) ; Buchta, Vladimír (referee) ; Gené, Josepa (referee)
The Trichophyton benhamiae complex encompasses several zoonotic pathogens that are of increasing concern to the scientific community due to their epidemic spread among pets and their owners. Of particular concern is the sudden appearance and rapid spread of T. benhamiae yellow phenotype strains in Europe. Considerable genetic and phenotypic variability has been revealed in the pathogens from the complex, yet the species limits and host spectra have not been clearly elucidated. To explore the diversity, epidemiology, and taxonomy of the T. benhamiae complex, my colleagues and I formed an international, cross-disciplinary team and applied a holistic One Health approach. We collected a large dataset of strains from several continents, along with associated data about host, clinical picture, and locality. Due to the high level of clonality in commonly used DNA sequence markers, I developed a new typing schema based on ten microsatellite markers and four DNA sequence markers. We then used a polyphasic approach combining data from independent analyses to decide on species limits in the T. benhamiae complex, including phylogenetic and population-genetic analyses, phenotypic and physiological analyses, mating-type gene characterization, ecological data and MALDI- TOF mass spectrometry analysis. Thanks to...
|
|
|
The Study of Bacterial and Fungal Microbiota of Human and Pets as a Possible Source of Antibiotic Resistance
Wipler, Jan ; Buchta, Vladimír (advisor) ; Kolář, Milan (referee) ; Bardoň, Jan (referee)
The study of shared bacterial and fungal microbiota of human and pets as a possible source of antibiotic resistance Summary: The microbiological aspect of the pet and owner relationship focuses on the microorganisms forming the microbiome. The sharing of the household by the owner and the pet is reflected in the two-way communication of the microbiota. The aims of the dissertation is to determine the microbial spectrum of bacteria and yeasts that can be cultivated in vitro in standard laboratory conditions. Antibiotic treatment in the last year could influence colonization by resistant microorganisms, therefore the abundance of shared bacterial and yeast species showing the same antimicrobial resistance phenotype between owners and their pets were monitored with respect to behavioral models. A total of 1156 samples were obtained from 120 owners' households and 80 control group participants without pet. Nasal mucosa, intertoe space, axillae, and auditory cannula swabs were collected from 145 owners and nasal mucosa and auditory cannula samples from 128 pets. 320 samples from the same anatomical locations like in owners were also provided to a control group of 80 people who have no contact with any animal for more than 1 year. All owners filled in a questionnaire with a statement regarding their relationship...
|
|
| |
|
|
Penetration of B-lactam antibiotics into cerebrospinal fluid and its relationship to inflammatory markers during invasive bacterial infection
Prášil, Petr ; Buchta, Vladimír (advisor) ; Marešová, Vilma (referee) ; Boštík, Pavel (referee)
Penetration of β-lactam antibiotics into cerebrospinal fluid and its relationship to inflammatory markers during invasive bacterial infection Aim: The penetration of β-lactam antibiotics (ceftriaxone, crystalic penicillin G - potassium salt and cefotaxime) into the cerebrospinal fluid (CSF) was estabilished and the correlation between the penetration and laboratory markers of inflammation was evaluated. Materials and methods: Levels of β-lactam antibiotics in serum and CSF were determined in 24 patients (76 samples). In all patients (n = 24) the CSF/serum ratio for antibiotics was calculated and it was correlated with laboratory markers of inflammation (C-reactive protein, fibrinogen, and CSF numbers of neutrophils). Besides, CSF was examined by a modified bactericidal test in patients (n = 13) with positive bacterial culture. In 14 patients (28 samples) levels of serum antibiotic concentration, both before and after its administration, were measured. Results: Serum levels of ceftriaxone before and after administration (31.2 mg/l ± SD 12.29 and 300.0 mg/l ± SD 125.9, respectively) differed with a statistical significance (p = 0.000156). Further, a significant difference between value of inflammatory markers and value of CSF/serum ratio (Kl/s) of ceftriaxone was observed. Patients with ratio values...
|
|
|
The antimicrobial activity of selective serotonine reuptake inhibitors.
Vlach, Jaromír ; Jílek, Petr (advisor) ; Buchta, Vladimír (referee)
1. Souhrn V naší práci jsme prokázali, že paroxetin a fluoxetin, látky ze skupiny selektivních inhibitorů zpětného vychytávání serotoninu (SSRI), mají antibakteriální účinek proti širokému spektru bakteriálních kmenů. Stanovili jsme minimální inhibiční koncentrace (MIC) obou látek mikrodiluční metodou v bujónu. MIC pro jednotlivé kmeny se pohybovaly v řádech desítek až stovek mg/l. Hodnoty MIC jsou vyšší v porovnání s průměrnými plazmatickými hladinami paroxetinu a fluoxetinu (desítky až stovky μg/l). Plazmatické hladiny však mohou stačit k ovlivnění patogenity mikroorganismu. Za určitých okolností, např. při kumulaci v centrálním nervovém sytému se mohou koncentrace in vivo blížit MIC stanoveným in vitro. SSRI vykazují aktivitu i proti houbám, rodům Candida a Aspergillus. Tyto látky jsou schopny potencovat účinek klasických antibiotik a zvrátit rezistenci odolných mikroorganismů. Svým působením na hladinu serotoninu v těle a inhibicí tvorby prostaglandinů ovlivňují a podporují činnost imunitního systému. SSRI mohou být nadějnou skupinou pro léčbu infekčních nemocí, mohou se stát užitečným doplňkem a alternativou stávajícím terapeutickým postupům, je však třeba je podrobit dalším a detailnějším výzkumům.
|
|
|
Study of stress factors in Candida albicans.
Vindušková, Renata ; Buchta, Vladimír (advisor) ; Podholová, Beata (referee)
Yeast cells, when growing on solid surfaces, form multicellular structures, colonies, with a characteristic organised morphologies, formed during the division of non- motile yeast cells. Organisation of yeast colonies should, therefore be ensured by signals transmitted and received by dividing cells within a colony In this regard, the yeast colony exhibits an analogy to embryogenesis of higher organisms, One of the characteristic attributes of multicellular organisms is their ability to emit and receive signals over long distances. Yeast colonies use for the long-range inter-colony signalling a simple volatile compound ammonia, produced by colonies in pulses. Ammonia action results in synchronisation of the development in neighbouring colonies. The transition of colonies from acidic phase to the phase of intense ammonia production (alkali phase) is connected with intensive metabolical changes. In this regard volatile ammonia acts as starvation signal between colonies. If we are able to influence cell communication for exampel by new antibiotics, we would protect ourselves against several mycoses.
|
|
|
Production of secreted aspartic proteinases by pathogenic yeasts.
Šlajchová, Andrea ; Buchta, Vladimír (advisor) ; Konečná, Klára (referee)
Charles University in Prague Faculty of Pharmacy in Hradec Králové Department of Biological and Medical Sciences Candidate: Andrea Šlajchová Supervisor: Doc. RNDr. Vladimír Buchta, CSc. Title of diploma thesis: Production of secreted aspartic proteinases by pathogenic yeasts The objective of this thesis was to identify the effect of farnesol as a quorum sensing molecule, which facilitates intracellular communication of Candida albicans, on the production of secreted aspartic proteinases (Sap). The theoretical section summarizes the morphology of Candida, the virulence factors, the illnessess cause by Candida and its treatment. A separate chapter focuses on secreted aspartic proteinases and on farnesol. The strains tested came from clinical isolates belonging to the Clinical Microbiology Institute of FN Hradec Kralove; two further strains were collected as well (10231 and 25188). The ATCC 10231 strain, which did not show farnesol production but the production of farnesol acid, was included in the test. Special media contained a source of bovine hemoglobin as the only source of nitrogen and had differing pHs. The strains were first pre-incubated to exogenous farnesol and later transfered to test media at various different concentrations of farnesol. The results were read after seven days of...
|
|
| |
|
|
Study of morphological and physiological aspects of Candida albicans growth in the relation to human hormones.
Vaculíková, Petra ; Buchta, Vladimír (advisor) ; Vejsová, Marcela (referee)
1. ABSTRACT Vaginal infection caused by yeasts is very frequent complication of women in fertile age.. One the most important predisposed factor are considered sexual hormones, especially estardiol. The results of clinical observations shows that this infection often occurs in women during the luteal phase of menstrual cycle, when estrogen and progesteron levels are elevated. We studied antifunal effect of sexual hormones on the growth of Candida albicans in combination with antifungal drugs. We used six clinical strains of Candida albicans from the patients with vulvovaginal candidiasis. A combination of one antifungal drug (fluconazole, amphotericin B, flucytosine) with a hormone (testosterone, progesterone, estradiol) was tested in all these strins. The results expressed as MIC of these combinations of hormone and antifungals were determined visually and spectrophotometrically. The best combination in terms of antifungal activity in vitro was amfotericin B with progesterone which showed addition. In contrast, combinations of flukonazol with all hormones were indifferent or antagonistic.
|
|
| |
guest ::
RSS feed.