All posts by Postępy Mikrobiologii

Fruktofilne bakterie kwasu mlekowego (FLAB) – nowa grupa heterofermentatywnych mikroorganizmów ze środowiska roślinnego

Fructophilic lactic acid bacteria (FLAB) – a new group of heterofermentative microorganisms from the plant environment
K. Gustaw, M. Michalak, M. Polak-Berecka, A. Waśko
30 June 2017

1. Wstęp. 2. Występowanie. 3. Cechy morfologiczne FLAB. 4. Cechy fizjologiczne FLAB. 5. Właściwości biochemiczne FLAB. 6. Filogenetyka. 7. Krótka charakterystyka wybranych gatunków z rodzaju Fructobacillus. 7.1. Fructobacillus fructosus. 7.2. Fructobacillus ficulneus. 7.3. Fructobacillus durionis. 7.4. Fructobacillus psedoficulneus. 7.5. Fructobacillus tropaeoli. 7.6. Lactobacillus kunkeei. 7.7. Lactobacillus florum. 8. Podsumowanie

Abstract: Recently, a unique kind of lactic acid bacteria (LAB) i.e. fructophilic lactic acid bacteria (FLAB), has been described. This specific group prefers D-fructose over D-glucose as a carbon source to growth. They can be found in fructose rich environments such as flowers, fruits and food products made of fermented fruits, for example tempoyak. In recent years, it has been revealed that insects which feed on food high in fructose are an abundant source of fructophilic bacteria. Bacterial communities inhabiting intestinal tracts of honeybees, bumblebees, Camponotus ants and tropical fruit flies were examined. At present FLAB includes six species: Fructobacillus fructosus, Fructobacillus durionis, Fructobacillus ficulneus, Fructobacillus pseudoficulneus, Fructobacillus tropaeoli and Lactobacillus kunkeei classified by Endo as obligatorily fructophilic, and only one species, namely Lactobacillus florum, as facultatively fructophilic. Latest publications describe new species of potential fructophilic characteristics, which suggests that there is still much to discover in that group.

1. Introduction. 2. Occurrence / Habitat. 3. Morphological characteristics of FLAB. 4. Physiological characteristics of FLAB. 5. Biochemical properties of FLAB. 6. Philogenetics. 7. Characterization of selected species of the genus Fructobacillus. 7.1. Fructobacillus fructosus. 7.2. Fructobacillus ficulneus. 7.3. Fructobacillus durionis. 7.4. Fructobacillus psedoficulneus. 7.5. Fructobacillus tropaeoli. 7.6. Lactobacillus kunkeei. 7.7. Lactobacillus florum. 8. Summary

Autor: Postępy Mikrobiologii
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Bacteroides spp. – znaczenie kliniczne, lekooporność i metody jej oznaczania

Bacteroides spp. – clinical significance, antibiotic resistance and identification methods
S. Niestępski, M. Harnisz E. Korzeniewska, A. Osińska, B. Dziuba
30 June 2017

1. Wstęp. 2. Systematyka bakterii z rodzaju Bacteroides. 3. Znaczenie kliniczne Bacteroides spp. 4. Oporność na leki u Bacteroides spp.
4.1. Bakterie z rodzaju Bacteroides jako rezerwuar determinantów oporności. 4.2. Oporność na środki przeciwdrobnoustrojowe. 5. Metody określania lekowrażliwości. 6. Podsumowanie

Abstract: Anaerobic Bacteroides species are dominant microbiota of the digestive tract of mammals. Along with other symbiotic bacteria located in the gastrointestinal tract, they contribute to the proper functioning of the organism. Some Bacteroides species are highly pathogenic. Virulence of these bacteria is related to their polysaccharide capsule, lipopolysaccharide and a variety of enzymes and enterotoxin. In recent years, an increase of antibiotic resistance in Bacteroides spp. has been noted, therefore the changes to the antibiotic resistance patterns in these bacteria should be monitored. This study summarizes the current knowledge about the bacteria of Bacteroides species.

1. Introduction. 2. Taxonomy of Bacteroides species. 3. Clinical significance of Bacteroides spp. 4. Antibiotic resistance. 4.1. Bacteroides species as a reservoir of antimicrobial resistance determinants. 4.2. Antimicrobial resistance. 5. Methods of drug resistance determination. 6. Summary

Autor: Postępy Mikrobiologii
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Amyloidy, białka powszechne wśród drobnoustrojów

Amyloids, common proteins among microorganisms
B.K. Pawłowska, B.M. Sobieszczańska
30 June 2017

1. Wprowadzenie. 2. Amyloidy bakteryjne. 2.1. Fimbrie spiralne. 2.1.1. Synteza fimbrii spiralnych. 2.1.2. Regulacja ekspresji operonu csg. 2.1.3. Udział fimbrii spiralnych w wirulencji bakterii. 2.1.4. Rola fimbrii spiralnych w patogenezie zakażeń człowieka. 2.2. Inne amyloidy bakteryjne. 2.3. Amyloidy grzybicze. 3. Podsumowanie

Abstract: Historically, the term amyloid was used strictly with reference to human neurodegenerative diseases. Nowadays, it is known that many proteins have the potential to conformational changes into β-sheet structures with tendency to form insoluble amyloid fibrils. Moreover, amyloid proteins are widespread among microorganisms. Bacteria and fungi produce functional amyloids which exhibit all characteristics of amyloid proteins, but in contrast to a numerous group of human toxic amyloids, they play important physiological functions in microorganisms. There is growing evidence that functional amyloids are important in bacterial adhesion and invasion. Furthermore, amyloids make biofilms thicker, rougher, and more resistant to drying out. The increasing interest in better understanding of the nature of these unusual microbial proteins and their role in pathogenesis are likely to contribute to the effective treatment or prevention of infectious diseases in humans.

1. Introduction. 2. Bacterial amyloids. 2.1. Curli fibers. 2.1.1. Curli biogenesis. 2.1.2. Regulation of csg operon. 2.1.3. Participation of curli in bacterial virulence. 2.1.4. Role of curli in pathogenesis. 2.2. Other bacterial amyloids. 2.3. Fungal amyloids. 3. Recapitulation

Autor: Postępy Mikrobiologii
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Mechanizmy toksyczności i transportu arsenu u mikroorganizmów

Mechanisms of arsenic toxicity and transport in microorganisms
S. Mucha, M. Berezowski, K. Markowska
30 June 2017

1. Wstęp. 2. Właściwości chemiczne i występowanie arsenu w środowisku. 3. Sposoby wnikania arsenu do komórek. 4. Mechanizmy toksycznego działania arsenu trójwartościowego. 4.1. Stres oksydacyjny. 4.2. Wiązanie z białkami. 4.3. Agregacja białek. 5. Toksyczność pięciowartościowego arsenu. 6. Mechanizmy detoksykacji komórek ze związków arsenu. 6.1. Operony ars. 6.2. Geny ACR. 6.3. Usuwanie koniugatów arsenu przez pierwotne transportery ABC. 6.4. Dwukierunkowy transport arsenu. 7. Podsumowanie

Abstract: Arsenic is an ubiquitous element present in the environment either through geological or anthropogenic activities. Millions of people all over the world are exposed to arsenic mainly via air, drinking water and food sources, which results in higher incidence of cancer. Several mechanisms by which arsenic compounds induce tumorigenesis have been proposed. Arsenic mediates its toxicity by generating oxidative stress, inducing protein misfolding, promoting genotoxicity, hampering DNA repair and disrupting signal transduction. Thus, all organisms have developed multiple pathways for arsenic detoxification. In this article, we review recent advances in the understanding of arsenic toxicity and its transport routes in prokaryotes and eukaryotes, including a dual role of aquaglyceroporins in the uptake and efflux, active transport out of the cell via secondary ion pumps and sequestration of metalloid-thiol conjugates into vacuoles by primary ABC transporters. We believe that such studies are of high importance due to the increasing usage of arsenic-based drugs in the treatment of certain types of cancer and diseases caused by protozoan parasites as well as for the development of bio- and phytoremediation strategies for metalloid-polluted areas.

1. Introduction. 2. The chemical properties and the presence of arsenic in the environment. 3. Pathways for arsenic uptake. 4. Mechanism of trivalent arsenic toxicity. 4.1. Oxidative stress. 4.2. Arsenic binding to proteins. 4.3. Protein aggregation. 5. Pentavalent arsenic toxicity. 6. Cellular detoxification mechanisms of arsenic compounds. 6.1. ars operons. 6.2. ACR genes. 6.3. Removal of arsenic conjugates by the ABC transporters. 6.4. Bi-directional transport of arsenic. 7. Summary

Autor: Postępy Mikrobiologii
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Czynniki odpowiedzialne za rozwój Lyme carditis

Factors responsible for the development of Lyme carditis
T. Chmielewski, S. Tylewska-Wierzbanowska
30 June 2017

1. Wstęp. 2. Lyme carditis – objawy, rozpoznanie i leczenie. 3. Patomechanizm zapalenia serca. 3.1. Ruch krętków. 3.2. Chemotaksja i adhezja. 3.3. Reakcje autoimmunologiczne. 4. Podsumowanie

Abstract: Borrelia burgdorferi sensu lato spirochetes are unique in many aspects. They are the etiological agents of Lyme borreliosis, meta-zoonotic, tick-borne disease of mammals, including humans. Ixodes spp. ticks are the vector. With the exception of erythema chronicum migrant (EM), manifestations of the disease may vary depending on the genospecies of Borrelia burgdorferi sensu lato. One of the symptoms is Lyme carditis. To date, the causative factors and the mechanisms of pathogenesis have not been well-described.
Borrelia burgdorferi spirochetes are considered as one of the most invasive mammalian pathogen. They are able to move through the skin, as well as break into and out of blood vessels, easily crossing the blood-brain barrier. Genes encoding various motility forms are bound with chemotaxis signaling system which leads and coordinates motion functions. The attachment of bacteria to host cells or extracellular matrix may promote colonization and disease development. Lyme disease spirochetes encode several surface proteins including decorin binding adhesion (DbpA), which varies among strains contributing to strain-specific differences in tissue tropism. The strains demonstrating the greatest decorin-binding activity promote the greatest colonization of heart and cause the most severe carditis. Moreover, the manifestation of Lyme carditis in certain hosts may be a result of an autoimmunological reaction due to molecular mimicry between B. burgdorferi and host self-components. In mammals, infection with B. burgdorferi induces the development of antibodies which may cross-react with myosin and neural tissue.

1. Introduction. 2. Lyme carditis – symptoms, recognition and treatment. 3. Patho-mechanism of Lyme carditis. 3.1. Spirochetes motility. 3.2. Chemotaxis and adhesion. 3.3. Autoimmunological reactions. 4. Summary

Autor: Postępy Mikrobiologii
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Current Issue

Advancements of Microbiology
Volume 63 (2024): Issue 3

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PTM

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