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Removal of antibiotics from wastewater by advanced oxidation technologies
Macsek, Tomáš ; Rusník,, Igor (referee) ; Bodík,, Igor (referee) ; Hlavínek, Petr (advisor)
Antibiotics are substances that inhibit the growth of microorganisms and are widely used in modern medicine. High consumption of antibiotics correlates with their elevated occurence in sewage systems, from where they are further released into the environment. The threat of their occurrence in the environment is in triggering the formation and spread of antibiotic resistance. This thesis focuses on the removal of selected antibiotics and partly on the antibiotic resistance from wastewater by advanced oxidation processes (AOPs). AOPs are based on the creation of highly reactive hydroxyl radicals, which are able to oxidize even highly persistent substances. The thesis focuses on the purification of effluents from municipal wastewater treatment plants (WWTP), which are identified as the main source of pharmaceutical pollution in the environment, by AOPs mainly based on ozonation. These processes were tested under laboratory conditions on model water as well as under real conditions as the tertiary stage of the treatment at Brno-Modřice WWTP under various operating states. As the results of the performed experiments show, it could be concluded that the studied AOPs are capable of effective degradation of studied antibiotics from the treated medium. Under real conditions, the antibiotics sulfamethoxazole, trimethoprim, azithromycin and clarithromycin were monitored. Output concentrations in each operational state were achieved to be below the limit of detection for all four antibiotics. The application of AOPs based on ozonation as the tertiary step of the treatment also had a positive effect on the reduction of microbial contamination and antibiotic resistance. Within the pilot plant experiments, a reduction of up to 4 orders of magnitude of E.coli, coliform microorganisms and a reduction of their resistant strains in the range of 1.4 - 4.0 logs were observed, compared to the effluent from the WWTP.
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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.
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Horizontální přenos genů rezistence mezi bakteriemi
Valach, Radek
Transfer of bacterial antibiotic resistence is highly discussed topic in past years. Its spreading is reason of creating super-resistant bacterial strains, that are resistant to a wide range of conventionally used drugs. Zinc oxide, used in pig farming as a feed supplement, has in recent years replaced antibiotics, given to prevent gastrointestinal disease and to promote growth. These substituent may increase transfer of genetic elements carying antibiotic resistence genes. This thesis is focussed on possible influence of zinc oxide and its nanoparts on Enterococcus faecalis bacteria. The aim of this work was to investigate whether the action of ZnO and ZnONPs would increase the transfer of a resistance gene plasmid between bacteria through the process of conjugation.
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Cellular factors influencing the antibiotic resistance by ABC-F proteins
Kýr, Jan ; Balíková Novotná, Gabriela (advisor) ; Dolejšová, Tereza (referee)
Antibiotic resistance is one of the main problems modern medicine has to face. In order to control it, it is important first to understand the mechanisms by which resistant pathogens bypass antibiotic treatment. One of the important protein families conferring resistance to 50S binding antibiotics is the ARE ABC-F protein family. A member of this protein family is the MsrA protein, which confers resistance to 14- and 15-membered macrolides. Loss-of-function mutations in the non-essential chaperone ClpX were found to a significant ly enhance the action of the MsrA protein. This leads to the significant increase in the resistance conferred by this protein. The exact mechanism by which ClpX affects MsrA function is still unknown. In this the diploma thesis was demonstrated that chaperone protein ClpX affects the resistance to erythromycin conferred by MsrA protein, due to the interaction with an unknown essential protein, which is mediated by a functional N-terminal zinc-binding domain of the chaperone. Furthermore, it was demonstrated in this work that loss of GluTR function influence the MsrA ability to confer resistance. The results of this work will bet he basis for further reasearch, which will lead to a more detailed understanding of the mechanism of resistance conferred by these proteins and...
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Faktory ovlivňující informovanost veřejnosti o antibiotikách
TUNKOVÁ, Barbora
Adequate knowledge of antibiotic use is one of the main prerequisites for preventing the spread of antibiotic resistance, which has become a public health threat in today's world. The aim of this study was to assess the impact of gender, education, and industry (food industry, agriculture, or healthcare) on awareness of antibiotics and antibiotic resistance through a questionnaire survey (n=799) and to compare antibiotic consumption (defined daily dose per 1000 inhabitants per year, DDD) in 16 European countries for the reporting period. Women were found to be more knowledgeable about the effects of antibiotics than men (p <0,0010). There was a statistically significant effect of education level and relevant discipline on knowledge regarding antibiotic resistance (p <0,0010). The highest average antibiotic consumption (21.97 DDD) was found in southern Europe, while the lowest antibiotic consumption was found in the Nordic countries (15,62 DDD).
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Stanovení antibiotické resistence u střevních bakterií selat krmených ZnO a nanočásticemi zinku
Janošťáková, Barbora
The present thesis investigated the antibiotic resistance of gut microbiota in piglets that have been fed supplements of zinc oxide (ZnO) and two types of zinc nanoparticles (ZnA and ZnC). First, an overview has been compiled to elucidate the emergence and spread of antibiotic resistance, possible remedies and their ecologic impact. Zinc nanoparticles have been proven to be more environmentally friendly and therefore a perspective replacement of zinc oxide, which is soon to be removed from use in prevention. This aim of this thesis was to evaluate their ability to prevent antibiotic resistance. To do so, an experiment has been conducted using gut Escherichia coli isolate samples obtained from 100 weaned piglets. The piglets have been randomly sorted into groups of 10 and fed a zinc supplement of set concentration: the control group received no supplementation, the rest of the groups received either ZnO, ZnA or ZnC in a concentration of 500, 1000 or 2000 mg per kilogram of compound feed. The piglets were supplemented for 10 consecutive days, their gut microbiota samples have been collected throughout the duration of the experiment and analysed for antibiotic resistance. Nanoparticles ZnC proved to be a sound alternative to ZnO, having significantly reduced the resistance to most studied antibiotics. The most effective of ZnC group dosing appeared to be 1000 mg/kg of compound feed.
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Occurrence of Streptococcus agalactiae in pregnant women
VETCHÁ, Sára
Streptococcus agalactiae is a human opportunistic commensal pathogen. The natural reservoir of this bacteria is the vagina, gastrointestinal tract, and nasopharynx. It induces a disease only in the compromised hosts, to whom it can cause a life-threatening infection. In the female body, Streptococcus agalactiae usually spreads from the gastrointestinal tract to the vaginal and birth canal area. The birth canal is where transmission and the resulting infection of a newborn can happen during delivery. The goal of the theoretical part was to introduce a matter of the disease caused by Streptococcus agalactiae and the possibilities of its laboratory diagnosis. This thesis presents information about Streptococcus agalactiae and its cultivation and diagnosis used for obtaining evidence about its presence, leading to antibiotics sensitivity determination. Streptococcus agalactiae is a bacteria from the group of streptococcus, hence the bacterial (prokaryotic) cell composition is described, and general information about the group of streptococcus is included. The main goal of the practical part was to carry out the screening and cultivation examination of the vaginal swab of pregnant women. In case of a positive result, to observe a different antibiotic resistance followed by processing the positive findings of laboratory samples. The laboratory allowed me to process 80 samples from women 35-37 weeks pregnant. I did a screening and cultivation examination and then I confirmed or denied the presence of Streptococcus agalactiae in the sample using a latex agglutination or CAMP test. Out of 80 samples, 19 pregnant women were Streptococcus agalactiae positive, presenting 23,75 % of the total. I used a disc diffusion test method to prove an antibiotics sensitivity for positive samples. The results of this bachelor thesis can be used as a source of information.
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Diagnostics and therapy of polyresistant bacteria in the Hospital Havlíčkův Brod
KOSTKOVÁ, Monika
Antibiotic resistance is a problem not only in our country but also in the world. The incidence of polyresistant bacterial species, which cause serious and difficult-to-treat infections, is increasing. This issue has implications for both patients' health and healthcare costs. The practical part of my bachelor thesis was performed in the Laboratory of clinical mikrobiology (ONHB). Samples were taken from ONHB, from the Psychiatric Hospital and from general practitioners from around Havlíčkův Brod. In my work, I visited strains of Klebsiella pneumoniae and Pseudomonas aeruginosa, which are often the cause of nosocomial infections. The first step was the correct isolation and diagnosis of bacteria and examination of the susceptibility of bacteria to antibiotics, where I used the disk diffusion method, the minimum inhibitory concentration and methods for the detection of broad-spectrum -lactamases. The aim of this work was to determine the representation of the number of these bacteria in the community and in the hospital environment, where I assumed that the incidence of resistant bacteria in the hospital environment is higher. I also dealt with the development of resistance of these bacteria to given antibiotics in the period 2017-2022. In conclusion, I drew attention to the correct principles of antibiotics and thus to the prevention of antibiotic resistance, as well as the possibilities of prevention and treatment of nosocomial infections.
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Subcellular localization of resistant proteins Vga(A)LC and Msr(A) using fluorescence microscopy
Nguyen Thi Ngoc, Bich ; Balíková Novotná, Gabriela (advisor) ; Lichá, Irena (referee)
Vga(A)LC and Msr(A) are clinically significant resistant proteins in staphylococci that confer resistance to translational inhibitors. They belong to ARE ABC-F protein subfamily, which is part of ABC transporters. Unlike typical ABC transporters, ABC-F proteins do not have transmembrane domains that are responsible for the transport of substances through the membrane. Therefore, they do not have characteristic transport function but regulatory or resistance function. Their mechanism of action on the ribosome has been described only recently, where these proteins displace the antibiotic from the ribosome. However, some aspects of their function are still unclear. For example, what is the function of the Vga(A) location on a membrane that has been detected in the membrane fraction but not in the ribosomal. In this work, using fluorescence microscopy, I observed subcellular localization of the Vga(A)LC-mEos2, Vga(A)LC-GFP and Msr(A)-eqFP650 resistant fusion proteins in live cells of S. aureus under different culture conditions . It has been shown that Vga(A)LC-GFP and Msr(A)-eqFP650 occur in a foci near the membrane. Depending on ATPase activity or the presence of an antibiotic, the localization of Msr(A)-eqFP650 in the cell changes from focal to diffuse, presumably on ribosomes, suggesting a...
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Mechanism of inducible gene expression of resistance protein Vga(A)LC from Staphylococcus haemolyticus.
Novotná, Michaela ; Balíková Novotná, Gabriela (advisor) ; Lišková, Petra (referee)
The staphylococcal protein VgaA belongs to ARE ABCF family, which confers resistance to ribosome binding antibiotics by the target protection mechanism. VgaA confers resistance to lincosamides, streptogramins A and pleuromutilins and thus provides the so-called LSAP resistance phenotype. The expression of resistance genes often reduces fitness in the absence of an antibiotic, therefore the expression of resistance genes is often tightly controlled and triggered only in response to the presence of an antibiotic to which the protein confers resistance. The inducible expression has also been observed for the vgaA gene, nevertheless, its mechanism has not been elucidated. In the diploma thesis, it was shown that the vgaALC gene from Staphylococcus haemolyticus is regulated by ribosome-mediated attenuation. The mechanism is based on the detection of translation inhibitors via a ribosome translating a special regulatory open reading frame (uORF), which is part of an attenuator located in the 5' untranslated region of the mRNA. The vgaALC gene is regulated at the transcriptional level in response to LSAP antibiotics. Antibiotic specificity of induction is affected not only by the nature of the peptide encoded by uORF but also by the antibiotic specificity of the resistance protein. Fluorescence microscopy...
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