All posts by Postępy Mikrobiologii

Koncepcja chromidu i jej znaczenie dla klasyfikacji pozachromosomowych replikonów bakterii

The concept of chromid and its influence on the classification of bacterial extrachromosomal replicons
J. Czarnecki, D. Bartosik
1 July 2017

1. Wprowadzenie. 2. Nazewnictwo replikonów niezbędnych. 3. Koncepcja chromidu. 4. Identyfikacja i klasyfikacja chromidów. 5. Chromidy w genomach bakterii. 6. Ewolucyjne korzyści wynikające z obecności chromidów. 7. Podsumowanie

Abstract: Extrachromosomal replicons are common components of bacterial genomes. While the genetic information essential for growth and division of bacterial cells is located within the chromosome, the extrachromosomal replicons, usually classified as plasmids, can provide functions which are critical for the survival of a bacterium in a specific environment; however, they are not indispensable for the viability of the host cells. Comparative genomic studies revealed that in many bacterial genomes some chromosomal genes had been transferred into the co-occurring plasmids. This phenomenon has led to the generation of essential extrachromosomal replicons, called chromids, sharing features of both chromosomes and plasmids. The prevalence of chromids in bacteria and their conserved character within certain taxonomic groups suggest an important role for these replicons in the evolution of bacteria.

1. Introduction. 2. Nomenclature of essential replicons. 3. The concept of chromid. 4. Identification and classification of chromids. 5. Chromids in bacterial genomes. 6. Evolutionary significance of chromids. 7. Summary

Autor: Postępy Mikrobiologii
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Mikrobiosensory beleczkowe w mikrobiologii

Application of cantilever-based microbiosensors in microbiology
A. Wańczyk, B. Łabędź, Z. Rajfur
1 July 2017

1. Wstęp. 2. Przystosowanie układu do precyzyjnych pomiarów biologiczno-chemicznych. 3. Zastosowanie mikrobiosensorów beleczkowych w pomiarach  biologicznych. 3.1. Mikrobiologia. 3.1.1. Wykrywanie mikroorganizmów. 3.1.2. Określanie masy mikroorganizmów. 3.1.3.Badanie wzrostu mikroorganizmów. 3.2. Proteomika. 3.3. Inne zastosowania mikrobiosensorów beleczkowych. 4. Podsumowanie

Abstract: This paper presents applications of cantilever-based microbiosensors in microbiology and other biological fields. These devices can be employed in a wide range of experiments due to their high sensitivity and capability of performing label-free and real-time measurements. Cantilever-based microbiosensors are employed in a variety of measurements, such as single cell mass, concentration of specific substances, their density and viscosity, fluid flow velocity, heat of reaction or detection of trace amounts of specified substances. All these applications ares possible, because cantilever surface can be specifically functionalized. In the last few years, the cantilever-based microbiosensors have been significantly improved to obtain even higher precision of measurement which allows for their new, unique applications with live biological systems.

1. Introduction. 2. Adaptation of the system for precise bio-chemical measurements. 3. Application of cantilever-based microbiosensors in biological  measurements. 3.1. Microbiology. 3.1.1. Detection of microorganisms. 3.1.2. Microorganism mass determination. 3.1.3. Microorganism growth studies. 3.2. Proteomics. 3.3. Other applications of cantilever-based microbiosensors. 4. Summary

Autor: Postępy Mikrobiologii
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Drożdże w bioindykacji zanieczyszczeń rolniczych

Yeast as bioindicators of agricultural pollution
U. Wachowska, A. D. Stasiulewicz-Paluch
1 July 2017

1. Wstęp. 2. Drożdże. 3. Przydatność drożdży do oceny zanieczyszczeń środowiska. 3.1. Środki ochrony roślin w środowisku. 3.2. Biotesty w oparciu o hamowanie wzrostu. 3.3. Testy genotoksyczności. 3.4. Testy endokrynne. 4. Drożdże w toksykogenomice. 4.1. Zalety drożdży wykorzystywanych w toksykogenomice. 4.2. Narzędzia transkrypto-, proteo- i matabolomiczne stosowane w toksykogenomice drożdży. 4.3. Toksykogenomika funkcjonalna genów drożdży. 4.4.  Toksykogenomika drożdży w ocenie zanieczyszczenia środowiska rolniczego. 5. Podsumowanie

Abstract: This review paper discusses a new set of biotests used for toxicity assessment of plant protection products and their residues in agricultural ecosystems. Recent regulations have imposed restrictions on the use of animals for scientific purposes, and also the obligation to analyze auxiliary substances in plant protection products and to identify endocrine disrupters. The major characteristics of yeasts and their taxonomic classification are describedin the study. Commercial yeast-based biotests and potential uses of yeasts in environmental studies and toxicogenomics are also analyzed.

1. Introduction. 2. Yeast. 3. Yeast as indicators of environmental pollution. 3.1. Plant protection products in the environment. 3.2. Growth inhibition biotests. 3.3. Genotoxicity tests. 3.4. Endocrine tests. 4. Yeasts in toxicogenomics. 4.1. The advantages of using yeasts in toxicogenomics. 4.2. Transcriptomics, proteomics and metabolomics tools in yeast toxicogenomics. 4.3. Yeast functional toxicogenomics. 4.4. Yeast toxicogenomics in agricultural pollution assessment. 5. Conclusions

Autor: Postępy Mikrobiologii
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Udział czynników wirulencji Enterococcus faecalis w rozwoju chorób miazgi i tkanek okołowierzchołkowych

Virulence factors of Enterococcus faecalis in relation to pulp diseases and periapical infections
E. Prażmo, R. Godlewska, M. Kwaśny, A. Mielczarek
1 July 2017

1. Wstęp. 2. Znaczenie E. faecalis w zakażeniach endodontycznych zębów. 3. Czynniki wirulencji E. faecalis. 4. Mechanizmy zjadliwości E. faecalis. 5. Podsumowanie

Abstract: Enterococci are Gram-positive, catalase-negative, facultative anaerobic bacteria. They inhabit the oral cavity and gastrointestinal tract in humans as normal commensals. However, they can also cause infections of the urinary tract, surgical wound infections, neonatal sepsis and endocarditis. Enterococcus faecalis is associated with great number of refractory endodontic infections. The prevalence of these bacteria ranges from 24 to 77% in teeth with failed endodontic treatment and E. faecalis very often coexists with chronic apical periodontitis. Understanding the virulence, ecology and epidemiology of E. faecalis is essential for limiting all kinds of diseases caused by this pathogen. This article focuses on the bacterial mechanisms related to endodontic infections and periradicular inflammatory response. The most explored virulence factors are: the aggregation substance, surface adhesins, lytic enzymes, lipoteicholic acid, sex pheromones. All of them are associated with specific stages of tissue invasion. E. faecalis has also developed elaborated mechanisms of antibiotic resistance, as well as the ability to organize in a biofilm and overcome low-nutrient conditions. These adaptations help in the modulation of host immune response and make E. faecalis very difficult to eradicate by available antibiotics and disinfectants. Recognition and understanding of the nature of this pathogen will help endodontic microbiology to completely eliminate endodontic infections for successful endodontic treatment.

1. Introduction. 2. Importance of E. faecalis in endodontic infections. 3. Virulence factors of E. faecalis. 4. Virulence mechanisms of E. faecalis. 5. Summary

Autor: Postępy Mikrobiologii
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Modulacja humoralnej odpowiedzi odpornościowej gąsienic Galleria mellonella przez enzymy proteolityczne bakterii Pseudomonas aeruginosa

Modulation of the humoral immune response in Galleria mellonella larvae by proteolytic enzymes produced by Pseudomonas aeruginosa
M. Andrejko
1 July 2017

1. Wstęp. 2. Barciak większy (Galleria mellonella) jako organizm modelowy. 3. Wrażliwość gąsienic G. mellonella na zakażenie P. aeruginosa. 4. Wpływ proteaz P. aeruginosa na reakcje immunologiczne gąsienic G. mellonella. 4.1. Układ oksydazy fenolowej. 4.2. Lizozym (muramidaza, glikohydrolaza mukopeptydowa, EC 3.2.1.17). 4.3. Peptydy o właściwościach przeciwdrobnoustrojowych (peptydy odpornościowe). 4.4. Apolipoforyna III (apoLp-III). 5. Podsumowanie

Abstract: The greater wax moth G. mellonella is a useful model organism for investigations of pathogenicity and identification of P. aeruginosa virulence factors. Strains differing in the protease profiles elicit different responses of the G. mellonella immune system to infection. The immune response depends on the bacterial strain used and the composition of the bacterial culture medium. Proteases in the initial phase of infection activate the immune system (involving increased lysozyme synthesis, induction of synthesis of immune peptides and metalloproteinase inhibitors, and altered apolipophorin III levels), thereby increasing the antibacterial activity of insect hemolymph. As bacteraemia progresses, they overcome the humoral immune response of the host by inhibiting the phenoloxidase activity, degradation of immune peptides and apolipophorin III. Different proteases exhibit different involvement in the degradation of key elements of insect immune response and/or proteins, while immune peptides display varied sensitivity to proteolytic activity. Elastase B has a double role during infection: it is an inducer of immune response (involving induction of antimicrobial peptide synthesis and metalloproteinase inhibitors, and increasing expression and activity of lysozyme and the level of apolipophorin III) and a virulence factor involved in the degradation of antimicrobial peptides. Increased quantities and activity of lysozyme in the hemolymph of larvae infected with the P. aeruginosa indicates that lysozyme is not very sensitive to the activity of bacterial proteases. Induction of synthesis of humoral immune response factors in G. mellonella larvae in the presence of metalloproteinases (elastase B) implies the “danger” resistance model in this organism.

1. Introduction. 2. Greater wax moth Galleria mellonella as a model system. 3. Sensitivity of G. mellonella larvae to infection with P. aeruginosa. 4. Effect of P. aeruginosa proteases on G. mellonella immune response. 4.1. Phenoloxidase system. 4.2. Lysozyme (muramidase, mucopeptide glycohydrolase, EC2.2.1.17). 4.3. Antimicrobial peptides (immune peptides). 4.4. Apolipophorin-III. 5. Summary

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Advancements of Microbiology
Volume 63 (2024): Issue 3

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PTM

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