Wyniki wyszukiwania - Biblioteka Nauki

1

Measurement of bacterial adhesion to metal surfaces with different chemical composition - evaluation of different methods

100%

Żywicka A. , Fijałkowski K.

Environmental Biotechnology

|

2017

|

tom Vol. 13, No. 2

14--22

EN

In the current study attention has been focused on the evaluation of different methods of measurement of bacterial adhesion to the metal surfaces with different chemical composition. The direct methods, which included determination of the number of bacterial cells using fluorescence microscopy and Colony Forming Units (CFU) on agar medium, and indirect methods using Alamar Blue (AB) and MTT assays, were evaluated. The chemical compositions of the metal surfaces included: copper, iron, chromium and nickel. Interaction effects of assay and metal compound have been specifically demonstrated in this study. It was found that metal ions reacted with components of the indirect colorimetric tests used in his study (AB and MTT assay). Consequently, those tests gave positive false results. In contrast to the indirect methods, direct counting methods such as microscopy techniques and CFU counting, were successfully applied for evaluation of bacterial adhesion to the metal surfaces. However, considering the limits for the surfaces of the examined samples for microscopy, the determination of the CFU was found to be the best method for testing the adhesion to metal surfaces. The method, combined with the appropriate detachment procedures allowed for a precise determination of the number of bacteria on the entire surface of the evaluated metal samples.

2

The influence of iron occurring in the growth medium of Staphylococcus aureus on the bacterial adhesion to collagen

75%

Krajewska-Pietrasik D. , Sobis-Glinkowska M. , Sidorczyk Z. , Mikucki J,

Acta Microbiologica Polonica

|

1997

|

tom 46

|

nr 4

3

Application of rapid Caco-2 cell culture system in the studies on the bacterial adhesion and transepithelial transport

75%

Olejnik A. , Marecik R. , Skrzypczak M. , Czaczyk K. , Grajek W.

|

tom 58

|

nr 3

EN

The aim of the presented work was the functional comparison of conventional 21-day-old and modified 6-day-old Caco-2 cell cultures for their application in studies on the bacterial adhesion and transepithelial transport. In the short-term culture system, the cells were grown on polycarbonate filters in serum reduced medium supplemented with a combination of growth factors. Morphological comparison of two Caco-2 monolayers showed that the short-term culture had the similar ultrastructural characteristics of the long-term well-developed culture. The transepithelial electrical resistance measurement confirmed the high Caco-2 monolayer integrity in both cell culture systems. As a result, the modified 6-day-old Caco-2 culture could be applied in permeability and adhesion investigations. In the transport study, atrazine was used as a model molecule. The transport of atrazine was symmetric between the apical to basolateral and the basolateral to apical directions and independent of its concentration. No significant difference was found in atrazine permeability through conventional and modified Caco-2 cultures. In order to investigate the role of Caco-2 culture protocol might play in the adhesion of probiotic bacteria, three lactobacilli strains were used. The effect of Caco-2 culture modification on adhesion capacity of all tested bacteria was not observed. The proposed system of Caco-2 cell culture can be a considerable alternative to the conventional 21-day system.

4

Efficacy of UV treatment in the management of bacterial adhesion on hard surfaces

63%

Kolappan A. , Satheesh S.

|

nr 2

EN

The efficacy of UV treatment to control bacterial adhesion onto hard surfaces was investigated in laboratory conditions. The major characteristics necessary for biofilm formation like extracellular polymeric substance (EPS) production, carbohydrate and protein concentration in EPS, and adhesion ability onto hard surface were studied using two bacterial strains isolated from marine biofilms. The results showed that there was a considerable difference between the control and UV treated bacterial cultures in their viability, production of EPS, and adhesion ability. The protein and carbohydrate concentration of the EPS and the adhesion of bacterial cells to surface were also considerably reduced due to UV treatment. This study indicates that treatment of water with UV light may be used to control biofilm development on hard surfaces.

5

Exopolysaccharide production by Bacillus strains colonizing packaging foils

51%

Szumigaj J. , Zakowska Z. , Klimek L.

|

2008

|

tom 57

|

nr 4

EN

The influence of the chemical composition of medium, availability of glucose and pH on the production of exopolysaccharides (EPS) by different Bacillus strains were investigated. Bacillus strains were isolated from the surface of polyethylene foils modified with mineral compounds after their biodégradation in compost soil. Moreover, the effect of EPS production on bacterial adhesion onto the surface of the materials was examined. The enhanced synthesis of exopolysaccharides in nutrient-starved conditions was revealed. The most effective synthesis of polymers was observed during the logarithmic phase of culture growth. The increased amount of EPS facilitated bacterial adhesion to material surfaces. It was determined that the biofilm on the material surface positively affects its biodégradation. Based on the results, we conclude that the biodégradation of polymers may be accelerated in low-nutrient environment.

6

Poszukiwanie prostych modeli do badania adhezji bakterii probiotycznych

44%

Czaczyk K. , Olejnik A. , Miezal P. , Grajek W.

|

tom 12

|

nr 1

84-96

PL

Przeprowadzono studia porównawcze nad możliwością zastąpienia w badaniach adhezji bakterii mlekowych modelu kultury komórek nabłonka jelitowego innymi uproszczonymi modelami. Badano przyczepność bakterii probiotycznych Lactobacillus casei Shirota ATCC 39539, Lactobacillus acidophilus LC1 oraz Lactobacillus rhamnosus GG ATCC 53103 do membran wykonanych z alginianu, karagenu, żelatyny, kolagenu, szkła, polistyrenu i karboksymetylocelulozy. Zaobserwowano największy stopień przyczepności bakterii probiotycznych do membran wykonanych z karboksymetylocelulozy i kolagenu. W większości wariantów doświadczeń liczba przyczepionych komórek bakteryjnych wzrastała wraz ze wzrostem czasu ich kontaktu z powierzchnią stałą. Wykazano także różnice w przyczepności komórek do hydrożeli o różnych stężeniach. Na podstawie przeprowadzonych badań można stwierdzić, że stopień adhezji bakterii probiotycznych do różnych powierzchni organicznych i nieorganicznych jest cechą zaleną od szczepu mikroorganizmu. Żaden z prostych modeli adhezyjnych, zastosowanych w tej pracy, nie charakteryzował się adhezyjnością porównywalną z komórkami nabłonka jelitowego Caco-2 i HT-29, stosowanego obecnie jako główny model in vitro do badań adhezji bakterii probiotycznych.

EN

Comparative studies were performed on the possibility of replacing intestinal epithelial cells by some other simplified models for the purpose of examining the adhesion of probiotic bacteria. The adhesion of Lactobacillus casei Shirota ATCC 39539, Lactobacillus acidophilus LC1, and Lactobacillus rhamnosus GG ATCC 53103 to surfaces of alginate, carrageenan, gelatin, collagen, glass, polystyrene, carboxymethylcellulose, and to intestinal epithelial cells (Caco-2 and HT-29 lines) were tested. Among the examined solid surfaces, the highest degree of adhesion was observed in the case of carboxymethylcellulose and collagen. In the majority of experimental variants, the number of bacterial cells adhering to surfaces increased parallel to the time of their contacting a solid surface. Additionally, there were stated differences in the cell adhesion to hydrogels showing varying concentration rates. On the basis of the experiments performed, it is possible to state that the adhesion degree of probiotic bacteria to various inorganic and organic surfaces is a parameter that depends on the strain of a microorganism. Among all the simplified models applied in the studies in question, no one was marked by an adhesion rate comparable to the adhesion of intestinal epithelial cells Caco-2 and HT-29, which are, nowadays, used as a major model in vitro while investigating the adhesion of probiotic bacteria.

7

Biosynteza egzopolisacharydow i ich rola w adhezji Bacillus megaterium do powierzchni stali nierdzewnej

38%

Czaczyk K. , Myszka K.

|

2004

|

tom 11

|

nr 3

PL

Celem badań było określenie wpływu dostępności składników odżywczych w środowisku wzrostu na biosyntezę egzopolisacharydów (EPS) przez Bacillus megaterium. Określano także zależność pomiędzy ilością produkowanych EPS a adhezją bakterii do powierzchni stali nierdzewnej (304L). W celu oszacowania ilości syntetyzowanych egzopolisacharydów zastosowano metodę polegającą na oddzieleniu ich za pomocą fal ultradźwiękowych i spektrofotometrycznym oznaczeniu po kwaśnej hydrolizie. Badanie adhezji Bacillus megaterium przeprowadzono nową, nieopisywaną dotąd w literaturze, metodą szacowania stopnia adhezji wg 9-stopniowej skali. Wykazano, że w większości wariantów doświadczenia biosynteza egzopolisacharydów wystąpiła w największym stopniu w początkowych etapach hodowli (4. i 8. godzina). Przy braku źródła azotu w pożywce, przez pierwsze 24 godz. hodowli nie stwierdzono obecności pozakomórkowych węglowodanów. Ich wzmożoną produkcję odnotowano dopiero w 48 godzinie trwania procesu i to na bardzo wysokim poziomie (0,035 mg EPS/106 jtk). W większości wariantów doświadczenia wykazano korelację pomiędzy ilością syntetyzowanych egzopolisacharydów na poszczególnych etapach hodowli a adhezją komórek Bacillus megaterium do powierzchni stali nierdzewnej. Zaobserwowano także pojawienie się wyższych stopni adhezji przy niskiej produkcji zewnątrzkomórkowych polisacharydów, co może świadczyć o tym, że w takich warunkach inne czynniki, oprócz biosyntezy egzopolisacharydów, odgrywają istotną rolę w procesie adhezji drobnoustrojów do powierzchni nieożywionych.

EN

The purpose of this investigation was to determine the effect of availability of nutritious components in a culture medium on the biosynthesis of exopolysaccharides (EPS) Bacillus megaterium. Furthermore, a dependence between the amount of EPS produced and the adhesion of bacteria to stainless steel surface (304L) was defined. For the purpose of determining the amount of EPS synthesized, they were separated by ultrasonic waves and, after the acid hydrolysis accomplished, a spectrophotometric assay was applied. The adhesion of Bacillus megaterium was investigated by an absolutely novel method of estimating degrees of adhesion on a nine-degree scale; so far, this method has not been mentioned in any literature. It was proved that in the majority of experimental cases, the highest level of the EPS biosynthesis occurred at the beginning of this process (during the 4th and 8th hour). When the source of nitrogen was unavailable during the initial 24 hours of the process, no extracellular carbohydrates were present. An intensified production of carbohydrates was reported only during the 48th hour of the process ensuing, with a very high production level (0,035 mg EPS/ 106 cfu). In the majority of experimental cases, it was proved that a correlation existed between the amount of synthesized exopolysaccharides, at each individual stage of development of the bacterial culture, and the adhesion of Bacillus megaterium cells to a stainless steel surface. Additionally, it was reported that the adhesion degree of bacteria was higher during a low production of extracellular polysaccharides. Tis fact shows that, besides the biosynthesis of exopolysacchariodes, some other factors play a significant role in the adhesion of micro-organisms to abiotic surfaces.