All posts by Postępy Mikrobiologii

Wybrane metody molekularne wykorzystywane w ocenie bioróżnorodności mikroorganizmów glebowych

Selected molecular methods used in assessing the biodiversity of soil organisms
M. Łyszcz, A. Gałązka
1 July 2017

1. Wstęp. 2. Metody klasyczne stosowane do identyfikacji bakterii. 3. Metody molekularne stosowane do identyfikacji mikroorganizmów glebowych. 4. Analiza zawartości zasad G+C w DNA. 5. Hybrydyzacja kwasów nukleinowych. 6. Analiza sekwencji kwasów nukleinowych. 7. Podsumowanie

Abstract: Biodiversity and the identification of new important features of microorganisms is crucial for the development of biotechnology. The current knowledge about microbs in natural environments is limited, thus the analysis of the microbial diversity in nature is not an easy task. So far, only a small percentage of prokaryotic microorganisms has been identified. It is believed that the soil environment is one of the richest reservoirs of microorganisms, as approximately 2 000 to 18 000 prokaryotic genomes can be isolated from one gram of soil. In this publication the selected methods used to identify microorganisms are presented. The first molecular marker used in the genetic identification of soil microorganisms was the analysis of the G+C base content, sincemicroorganisms exhibit differences in the (G+C)/(A+T) relative factor. Another method used to identify bacteria is the nucleic acid hybridization. This technique involves a determination of the degree of similarity of DNA-DNA between two organisms. One of the most frequently used hybridization technique is FISH – fluorescent in situ hybridization. The most precise method for analyzing the nucleic acids is sequencing, i.e. determining the order of nucleotides which form the genetic information of the microorganism studied. Very often in molecular studies the 16S rDNA molecule is subjected to sequencing.

1. Introduction. 2. Classical methods used to identify bacteria. 3. Molecular methods used in the identification of soil microorganisms. 4. Analysis of the G+C DNA content. 5. Nucleic acid hybridization. 6. Analysis of nucleic acid sequences. 7. Summary

Autor: Postępy Mikrobiologii
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Właściwości i zastosowanie podłoży bakteriologicznych

Properties and uses of bacteriological media
A. Mikołajczyk, E. Stefaniuk, K. Bosacka, W. Hryniewicz
1 July 2017

1. Wstęp. 2. Przygotowywanie i przechowywanie podłoży. 3. Kontrola jakości. 4. Podział podłoży. 4.1. Podział ze względu na skład chemiczny. 4.2. Podział ze względu na konsystencję. 4.3. Podział ze względu na zawartość substancji odżywczych. 4.4. Podział ze względu na zastosowanie. 5. Podsumowanie

Abstract: The aim of this article was to collate information about bacteriological media, presenting their composition, properties and the resultingpossible applications of a particular medium or group of media in bacteriological diagnostics. The most important groups of culture media were classified basing on their composition (synthetic, semi-synthetic and natural), consistency (liquid, semi-solid, solid), nutrient content (minimum, nutrient-enriched) and use (transport, nutrient, selective, differential, selective-differentiating, for susceptibility testing). Taking into account the practical aspect, much space is devoted to the classification of culture media based on their possible use. For each group, several examples of culture media with their major components and bacterial species for which they are intended are given. Brief information about the quality assurance and control of media during their preparation, transport and storage is also presented.

1. Introduction. 2. Preparation and storage of media. 3. Quality control. 4. Classification of culture media. 4.1. Classification of culture media based on their composition. 4.2. Classification of culture media based on their consistency. 4.3. Classification of culture media based on their nutrient content. 4.4. Classification of culture media based on their use. 5. Summary

Autor: Postępy Mikrobiologii
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Probiotyki, a układ odpornościowy przewodu pokarmowego ssaków

Probiotics and mammalian gastrointestinal immune system
B. Tokarz-Deptuła, W. Deptuła
1 July 2017

1. Wstęp. 2. Probiotyki, a układ odpornościowy przewodu pokarmowego. 3. Podsumowanie

Abstract: Probiotics are microorganisms that provide health benefits when consumed. These are also food supplements or food products containing specified probiotic microorganisms. Probiotic microorganisms colonize the gastrointestinal tract of the host environment, reducing the risk of pathogenic bacteria growth and their potential impact on the regulation of host immune responses. They also have the ability to eliminate pathogenic bacteria. The administration of probiotic microorganisms in addition to chemotherapeutic agents and antibiotics improves therapy efficiency, since it results in restoration of the equilibrium between the local and general pro- and anti-inflammatory response.

1. Introduction. 2. The probiotics and the gastrointestinal immune system. 3. Conclusions

Autor: Postępy Mikrobiologii
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Mikroflora i parazytofauna obcych i inwazyjnych gatunków żółwi

Microflora and parasitofauna of alien and invasive turtle species
O. Goławska, M. Demkowska-Kutrzepa, E. Borzym, P. Różański, M. Zając, A. Rzeżutka, D. Wasyl
1 July 2017

1. Wstęp. 2. Inwazyjne gatunki żółwi. 3. Bakterie. 3.1. Salmonella spp. 3.1.1. Reptile Associated Salmonellosis (RAS). 3.2. Prątki. 3.3. Inne bakterie. 4. Parazytofauna żółwi. 4.1. Żółwie inwazyjne źródłem zarażenia helmintami żółwia błotnego. 4.2. Występowanie i patogenność obcych pasożytów u natywnych i obcych gatunków żółwi. 5. Infekcje wirusowe. 6. Infekcje grzybicze. 7. Podsumowanie

Abstract: Invasiveness of alien turtles results from their impact on the functioning of the local ecosystem. It is due to predation on or competing with resident species, but also transfer of new and unknown pathogenic bacteria, viruses, parasites, or fungi. Salmonella is the most often reported microorganism, both in free-living and captive turtles. Zoonotic aspect of Salmonella spp. carriage has led to the definition of RAS (Reptile Associated Salmonellosis) acquired from domestic pet reptiles. Mycobacterium spp., Leptospira spp. and aquatic bacteria are also found in turtles. Additionally, nematode transmissions from invasive turtles to the autochthonic ones have been described. Alien turtles were less affected by parasitic invasion than animals living in a native location, but the infestation of alien parasites in native turtle species was usually more severe. Reports on viral or fungal infections in turtles are scarce. The identified knowledge gaps justify the need for research which will provide basic and systematic data on microbial threats related to alien and invasive turtles present in the natural environment of Poland. It will also give more insight in the scope and the impact of the problem on epidemiology and public health.

1. Introduction. 2. Invasive turtle species. 3. Bacteria. 3.1. Salmonella spp. 3.1.1. Reptile Associated Salmonellosis (RAS). 3.2. Mycobacteria. 3.3. Other bacteria. 4. Parasitofauna of turtles. 4.1. Invasive turtles as a source of helminth invasion of European pond turtle. 4.2. Occurrence and invasiveness of alien parasites in native and alien turtles. 5. Viral infections. 6. Mycotic infection. 7. Conclusions

Autor: Postępy Mikrobiologii
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Metalotioneiny bakteryjne

Bacterial metallothioneins
A. Mierek-Adamska, W. Tylman-Mojżeszek, Z. Znajewska, G. B. Dąbrowska
1 July 2017

1. Wstęp. 2. Historia odkryć metalotionein u bakterii. 3. Budowa i sposób wiązania jonów metali ciężkich przez bakteryjne MT. 4. Funkcje metalotionein bakteryjnych. 5. Regulacja ekspresji bakteryjnych metalotionein. 6. Obecność metalotionein u bakterii. 7. Podsumowanie

Abstract: Heavy metals are found in all living organisms where, as indispensable microelements (e.g. zinc, iron, copper), are involved in endless metabolic processes. However, living organisms are also at a risk of exposure to highly toxic metals, including cadmium or lead, which do not play any physiological role. Among multiple mechanisms associated with the maintenance of micronutrient homeostasis and detoxification of unwanted metals, there is a family of low-molecular-weight, cysteine-rich proteins, able to chelate multiple metal ions i.e. the metallothioneins (MTs). They are widely distributed among Eucaryota, however, they have also been found in some limited Procaryota, including cyanobacteria, pseudomonads and mycobacteria. These bacterial MTs differ in terms of primary structure, the number and type of metal ions they bind, as well as with regard to their physiological functions. The expression of bacterial MTs is regulated by metals via metalosensors. MTs from cyanobacteria seem to be involved in zinc homeostasis, while in Pseudomonas they are linked to cadmium detoxification. In Mycobacterium, MTs bind copper ions and may play a pivotal role in the virulence of these bacteria. The presence of MTs in other groups of bacteria remains questionable. Problems with identification of new bacterial MTs are mainly associated with low level of homology between MT amino acid sequences of different bacterial groups. Further research is needed to evaluate the physiological functions of metallothioneins in Procaryota.

1. Introduction. 2. The history of discoveries of bacterial metallothioneins. 3. Structure and metal-binding properties of bacterial MTs. 4. Functions of bacterial metallothioneins. 5. Regulation of metallothionein gene expression. 6. Presence of metallothioneins in bacteria. 7. Summary

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

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PTM

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