Enterococcus faecalis is a Gram-positive facultative anaerobe involved in many fatal or refractory infections of humans. Silver, often used as silver ions (Ag+) or nanoparticles (AgNPs), is a strong and broad-spectrum antibacterial agent, but E. faecalis shows resistance against it. Despite this, the knowledge about the resistance of E. faecalis against silver is still lacking. In this study, the silver-resistant E. faecalis strains (AgR and ANR E. faecalis) were established through a serial selection method. Their biological and silver-resistant features as well as the Gene Ontology (GO) in comparison with the original E. faecalis were evaluated. The results showed that the silver-resistant E. faecalis could proliferate as original bacteria and had strong resistance against both Ag+ and AgNPs. The minimum bactericidal concentrations (MBCs) of AgNO3 on original, AgR, and ANR E. faecalis were 400 mg/L, 600 mg/L, and 500 mg/L, and the MBCs of AgNPs on these strains were 80 mg/L, 110 mg/L, and 130 mg/L, respectively. GO analysis revealed significant difference (P < 0.05) in gene expressions of biological process (BP), cellular component (CC), and molecular function (MF) among original, AgR, and ANR E. faecalis. These findings provided a significant basis for further understanding and managing the silver-resistance of E. faecalis in infection-control environments. The mechanism behind Ag+/AgNPs resistance of E. faecalis needs to be further investigated.
- MeSH
- antibakteriální látky chemie farmakologie MeSH
- bakteriální léková rezistence účinky léků genetika MeSH
- bakteriální proteiny genetika MeSH
- dusičnan stříbrný metabolismus farmakologie MeSH
- Enterococcus faecalis účinky léků genetika růst a vývoj fyziologie MeSH
- kovové nanočástice chemie MeSH
- lidé MeSH
- mikrobiální testy citlivosti MeSH
- regulace genové exprese u bakterií MeSH
- stříbro chemie farmakologie MeSH
- Check Tag
- lidé MeSH
- Publikační typ
- časopisecké články MeSH
UNLABELLED: PURPOSE OF THE STUDY The alloplastic materials currently used for protective surface layers on implants were tested in vitro under microbiological laboratory conditions by contamination with microbial agents most frequently found in deep infection of total joint replacements. The objective was to find out how the resistance to bacterial colonisation was related to different surface finishes. MATERIAL AND METHODS Each of 14 samples of alloplastic material currently used in the manufacture of orthopaedic implants was inoculated with each of the group of microorganisms most frequently infecting joint replacements; these were Staphylococcus aureus, Staphylococcus epidermidis, Pseudomonas aeruginosa, Enterococcus faecalis and Escherichia coli. At 24 hours of incubation, biofilms produced on sample surfaces were collected, stained with crystalline violet and assessed by spectrophotometry. The average value of biofilm absorbances (AV595) for the group of microorganism tested was taken as a basic characteristic of each material sample indicating its sensitivity to bacterial. RESULTS Of the metal materials with smooth surface finish, Vitalium (AV595, 0.368) showed the lowest affinity to microbial colonisation; next was titanium (AV595, 0.459) and steel (AV595, 0.505). A significant increase in sensitivity to bacterial colonisation was recorded in all types of surface finish of steel (AV595, 0.571) and in titanium alloy with a rough surface texture (AV595, 0.737 to 1.676); p < 0.05. Porous titanium surfaces significantly increased material affinity to colonisation. DISCUSSION Our study had certain limitations concerning in vitro evaluation of porous surfaces that have high affinity to bacterial colonisation. Porous titanium, and its hydroxyapatite layer in particular, considerably promotes osteoblast colonisation of the surface as well as implant osseointegration in the bone bed. Microorganisms therefore have no room for surface colonisation. Problematic may remain the surface parts outside contact with bone that keep their affinity to bacterial colonisation. CONCLUSIONS The material of choice for cemented implants is Vitalium which, of all metal surfaces, has the lowest sensitivity to bacterial colonisation. The materials of choice for cementless implants are titanium alloys. However, an osteoactive surface not in contact with bone remains a problem. On the one hand, its roughness and porosity are crucial to good osseointegration, on the other hand, its affinity to bacterial colonisation is high. KEY WORDS: alloplastic material, biofilm, joint replacement infection.
- MeSH
- artroplastiky kloubů přístrojové vybavení MeSH
- biofilmy růst a vývoj MeSH
- biokompatibilní materiály škodlivé účinky chemie MeSH
- Enterococcus faecalis fyziologie MeSH
- Escherichia coli fyziologie MeSH
- infekce spojené s protézou mikrobiologie MeSH
- lidé MeSH
- povrchové vlastnosti MeSH
- protézy a implantáty škodlivé účinky MeSH
- Pseudomonas aeruginosa fyziologie MeSH
- Staphylococcus aureus fyziologie MeSH
- Staphylococcus epidermidis fyziologie MeSH
- testování materiálů MeSH
- titan chemie MeSH
- vitalium chemie MeSH
- Check Tag
- lidé MeSH
- Publikační typ
- časopisecké články MeSH
Enterococcus faecalis is a ubiquitous bacterium of the gut that is observed in persistent periradicular infections. Its pathogenicity is associated with biofilm formation and the ability to survive under nutrient-poor (starvation) conditions. However, characteristics of chemical composition of biofilm cells developed by starved E. faecalis cells remain poorly understood. In this study, E. faecalis cells in exponential, stationary, and starvation phases were prepared and separately cultured to form biofilms. Confocal laser scanning microscopy was performed to verify biofilm formation. Raman microscopy was used to investigate the chemical composition of cells within the biofilms. Compared to cells in exponential or stationary phase, starved cells developed biofilms with fewer culturable cells (P < 0.05). Raman analysis revealed that cells produced in the biofilms from starved planktonic cells contained more protein and less nucleic acids than either the corresponding planktonic cells or the cells in biofilms from planktonic cells in exponential or stationary phases, suggesting that biofilm-grown cells from the starvation phase were characterized by increased synthesis of proteins and decreased nucleic acids. This study provides an insight into the chemical composition of biofilm cells developed by starved E. faecalis.
The subject of this study was to test the influence of regular consumption of kefir beverage (Danone company) comprising probiotic bacterial strains (Bifidobacterium animalis 108 CFU/g–1, Lactococcus lactis, Streptococcus thermophilus, Lactobacillus sp., Leuconostoc mesenteroides…), inulin, and yeasts (Debaryomyces hansenii, Pichia fermentas, Torulopsis holmii) on the incidence of Enterococcus faecalis in the human stool. Five hundred women (age 18–55), who had suffered from various forms of indigestion, were selected by questionnaires. We then selected from this group 50 volunteers who consumed a 200 ml kefir beverage regularly, each evening, after dinner. Their stool samples were taken before the research period started, and after two weeks of kefir beverage consumption. The women also filled in the questionnaire about their subjective feeling (alimentary function) after 14 days of kefir beverage consumption. The microbiological cultivation was carried out on a special medium Slanetz Bartley – pick-up Enterococcus faecalis (M 612 HiMEDIA). The average number of Enterococcus faecalis per 1 g of stool was 4.48.108 CFU at the beginning of the study (median 5.25.107 CFU, SD 1.18.109 CFU), while after 14 days of regular daily consumption of the kefir beverage the value determined was 3.32.107 CFU (median 2.65.106 CFU, SD 8.56.107 CFU). The sign test, resultant value u = 4.808326 (critical value 2.58 for statistical significance p = 0.01) showed that the difference in the counts of Enterococcus faecalis in the stool of individuals intervened prior and subsequent to the consumption of kefir beverage was statistically significant, p < 0.01. The counts of Enterococcus faecalis in the stool of individuals after kefir beverage consumption were significantly lower. A subjective evaluation of the women in the questionnaire showed that 93.5 % noticed, after a regular 14 days’ consumption of 200 ml kefir beverage, improved alimentary function in comparison with the period before the study (p< 0.001).
- MeSH
- bakteriologické techniky metody přístrojové vybavení využití MeSH
- Enterococcus faecalis fyziologie izolace a purifikace metabolismus MeSH
- feces enzymologie chemie mikrobiologie MeSH
- inulin fyziologie metabolismus MeSH
- kvasinky fyziologie metabolismus MeSH
- kysané mléčné výrobky fyziologie metabolismus využití MeSH
- lidé MeSH
- probiotika metabolismus terapeutické užití MeSH
- průzkumy a dotazníky MeSH
- trávicí systém - fyziologické jevy MeSH
- Check Tag
- lidé MeSH
- ženské pohlaví MeSH
