All posts by Postępy Mikrobiologii

Ocena działania chemicznych preparatów dezynfekcyjnych przeznaczonych do powierzchni z zastosowaniem metod nośnikowych. Działanie bakteriobójcze, drożdżobójcze i sporobójcze

Evaluation of chemical agents intended for surface disinfection with the use of carrier methods. Bactericidal, yeasticidal and sporocidal activity
P. Tarka, K. Kanecki, K. Tomasiewicz
2 July 2017

1. Wprowadzenie. 2. Co obowiązuje dzisiaj? Metody zawiesinowe w ocenie działania bakterio/drożdzo/grzybo/sporobójczego chemicznych preparatów dezynfekcyjnych przeznaczonych do powierzchni. 3. Co będzie obowiązywało? Metody nośnikowe w ocenie działania bakterio/drożdżobójczego chemicznych preparatów dezynfekcyjnych przeznaczonych do powierzchni. 4. Interakcje między materiałem chusteczki, a środkiem dezynfekcyjnym. 5. Przedłużony efekt działania preparatu dezynfekcyjnego. 6. Czas kontaktu preparatu dezynfekcyjnego z powierzchnią. 7. Perspektywy standaryzacji badań działania sporobójczego chemicznych preparatów dezynfekcyjnych przeznaczonych do powierzchni z użyciem nośników. 8. Podsumowanie

Abstract: Disinfection of surfaces in medical facilities is an important element in the control of hospital infections, including these caused by bacteria, viruses and spores. Disinfecting agents need to exhibit specific characteristics, namely potential killing activity towards test bacteria which was determined experimentally in the laboratory. The methods in which a suspension of test bacteria is subject to the given agent are most often applied. However, the suspension methods do not fully imitate the conditions present in reality. Thus, in order to determine the concentrations of chemical disinfecting agents, carrier methods are applied. The new European standard i.e. EN 16615 Chemical disinfectants and antiseptics – Quantitative test method for the evaluation of bactericidal and yeasticidal activity on non-porous surfaces with mechanical action employing wipes in the medical area (4-field test) – Test method and requirements (phase 2, step 2), is a completely new standard for testing chemical surface disinfecting agents. It allows not only to assess the reduction in the number of test bacteria on the carrier, but also to examine possible interactions between the disinfecting agent and the material of which tissues and cloths are made. Additionally, it enables the evaluation of possible transfer of bacteria to adjucent areas via wiping.

1. Introduction. 2. What is obligatory today? Suspension-based tests used for the evaluation of antimicrobial activity of chemical products used for surface cleaning. 3. What will be obligatory? Carrier tests used for the antimicrobial activity evaluation of chemical products used for surface cleaning. 4. Interaction between the carrier material and the disinfectant 5. Prolonged effect of disinfectants. 6. Interaction time between the disinfectant and the surface. 7. Estimation of anti-spore activity of disinfectants used for surface cleaning. Perspectives of standardization. 8. Summary

Autor: Postępy Mikrobiologii
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Model patogenezy enteropatogennych szczepów Escherichia coli – kluczowa rola adhezji

Model of enteropathogenic Escherichia coli pathogenesis – a key role of adherence
B. K. Pawłowska, B. M. Sobieszczańska
2 July 2017

1. Wprowadzenie. 2. Wyspa patogenności LEE. 2.1. Adhezja EPEC. 2.1.1. Fimbrie BFP. 2.1.2. Fimbrie typu 1. 2.1.3. Fimbrie powszechne E. coli. 2.1.4. Rzęski. 3. System sekrecji typu III. 3.1. Białka efektorowe EPEC. 3.2. Intimina. 3.3. Tir. 3.4. Destrukcja połączeń międzykomórkowych. 3.5. Zdolność inwazji i unikanie fagocytozy. 4. Wpływ EPEC na apoptozę komórek gospodarza. 5. Inne systemy sekrecji. 6. Typowe i atypowe EPEC. 7. Podsumowanie

Abstract: Escherichia coli is a highly diverse and one of the best characterized bacterial genus. The species comprises many commensal strains, colonizing human and animal intestines, as well as pathogenic strains, which can cause gastrointestinal infections. Enteropathogenic E. coli (EPEC) group strains is the pathotype of diarrheagenic E. coli, which is associated with infant diarrhea. The hallmark of EPEC infections is their ability to produce attaching and effacing (A/E) lesions as a result of intimate bacterial adherence to enterocytes and the translocation of bacterial proteins through type III secretion system. The multifunctional and interdependent properties of the effectors contribute to the host cell disruption. The consequences of EPEC infection are: the reorganization of the host cell cytoskeleton underneath adherent bacteria, inhibition of nutrient and water transport, mitochondrial dysfunctions, weak intestinal inflammation, epithelial barrier function disruption and severe watery diarrhea. Despite the recent knowledge development, the mechanism of EPEC diarrhea is still ambiguous. Due to the absence of a proper animal model, further studies should be conducted in volunteers or at least in primates to determine the underlying mechanisms.

1. Introduction. 2. Pathogenicity island LEE. 2.1. Adherence. 2.1.1. BFP pili. 2.1.2. Type 1 pili. 2.1.3. E. coli common pili. 2.1.4. Flagella. 3. Type III system of secretion. 3.1. Effector proteins of EPEC. 3.2. Intimin. 3.3. Tir. 3.4. Disruption of tight junctions. 3.5. Invasion ability and avoidance of phagocytosis. 4. Impact of EPEC on host cell apoptosis. 5. Other secretion systems. 6. Typical and atypical EPEC. 7. Summary

Autor: Postępy Mikrobiologii
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Mikrobiologiczna utylizacja celulozy

Microbial cellulose utilization
K. Poszytek
2 July 2017

1. Wprowadzenie. 2. Charakterystyka celulozy. 3. Mikroorganizmy celulolityczne. 4. Enzymy celulolityczne. 4.1. Podział systemów celulolitycznych. 4.2. Zasady funkcjonowania wolnych i skompleksowanych enzymów celulolitycznych. 4.3. Biologia molekularna oraz inżynieria genetyczna celulaz. 5. Ekologiczny i  praktyczny aspekt utylizacji celulozy. 6. Podsumowanie

Abstract: Lignocellulosic biomass, consisting of lignin, cellulose and hemicellulose, can be utilized as a substrate in the production of biofuels. Before application, lignocellulosic material requires preliminary treatment. Biological pretreatment, which can be an alternative to the physical and chemical methods, is based on the activity of microorganisms, mainly bacteria and fungi. They produce cellulolytic enzymes, cellulases, which can effectively degrade lignocellulosic biomass and other materials containing cellulose. At least three major groups of cellulases are involved in the hydrolysis process: endoglucanases, exoglucanases and β-glucosidases. Various types of cellulases exist in a free form or as complexes, known as cellulosomes. In order to increase the activity, cellulolytic enzymes can be modified by means of genetic engineering. The final results are intended to increase the efficiency of hydrolysis of lignocellulosic biomass and thus the process of biochemical changes in the context of biofuel production.

1. Introduction. 2. Characteristics of cellulose. 3. Cellulolytic microorganisms. 4. Cellulolytic enzymes. 4.1. Classification of cellulolytic enzymes. 4.2. Operating principles of free and complexed cellulolytic enzymes. 4.3. Molecular biology and genetic engineering of cellulases. 5. Ecological and practical aspects of cellulose utilization. 6. Summary

Autor: Postępy Mikrobiologii
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Mikroorganizmy w bioaugmentacji zanieczyszczonych środowisk

Microorganisms in bioaugmentation of polluted environments
A. Mrozik
2 July 2017

1. Wprowadzenie. 2. Mikroorganizmy w bioaugmentacji. 2.1. Pojedyncze szczepy. 2.2. Konsorcja mikroorganizmów. 2.3. Mikroorganizmy modyfikowane genetycznie. 3. Sposoby dostarczania mikroorganizmów do środowiska. 4. Czynniki ograniczające bioaugmentację. 5. Podsumowanie

Abstract: Bioaugmentation is defined as a technique for improving the degradative capacity of contaminated soil and water by adding selected strains or consortia of microorganisms. In the treatment of environmental pollution by microorganisms, three approaches can be distinguished: autochthonous bioaugmentation, in which microorganisms isolated from contaminated site as an enriched culture are reinjected to the original environment; allochthonous bioaugmentation (bioenrichment), in which seeding material is isolated from another place and gene bioaugmentation, in which genetically engineered microorganisms equipped with genes encoding proteins related to some desired function are introduced into polluted site. In the selection of proper culture for biougmentation, the following features of microorganism should be taken into consideration: fast growth, ease of culivation, capacity to withstand high concentration of contaminants and the ability to survive in a wide range of environmental conditions. The enhancement of bioaugmentation may be also achieved by delivering microorganisms on various carriers or by the use of activated soil. The efficiency of bioaugmentation is determined by abiotic and biotic factors. The first include chemical structure of contaminants, their concentration and bioavailability as well as fluctuations or extremes in temperature, pH and nutrients level. Among biotic factors, the most important are the interactions between autochthonous and added microorganisms such a competition, predation and bacteriophages. Numerous studies have demonstrated that bioaugmentation is a promising technology in remediation of soil, water and sediments polluted with polycyclic aromatic hydrocarbons, nitrophenols, polychlorinated biphenyls, chlorophenols, crude oil, diesel oil and several pesticides.

Introduction. 2. Microorganisms in bioaugmentation. 2.1. Single strains. 2.2. Consortia of microorganisms. 2.3. Genetically engineered microorganisms. 3. Methods for delivering microorganisms into environment. 4. Factors limiting bioaugmentation. 5. Summary

Autor: Postępy Mikrobiologii
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Advancements of Microbiology
Volume 63 (2024): Issue 3

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