In vitro estimation of the infectious potential of the enterococcal strain by an analysis of monocytes’ response to the formed biofilm

The aim of our study was to assess the possibility of predicting Enterococcus faecalis pathogenicity based on morphological changes of monocytes interacting with of bacteria and their adherence to biofilm. Changes in the size and granularity of monocytes, as well as their adherence to biofilm were assessed using FACScan flow cytometer after 1h co-incubation of monocytes and enterococcal biofilm in 37°C. The obtained results were validated with respect to monocytes incubated without bacteria. The most prominent changes in size of monocytes were observed in the case of commensal bacteria. The interaction with bacteria isolated from the blood stream and urine caused comparable changes in the size of THP-1 cells and were smaller than the changes of cells incubated with commensal bacteria. Changes in THP-1 granularity were comparable regardless of the source of bacteria forming biofilm. The parameter which differed the most was connected to the adherence index relating to the monocytes remaining on the surface of biofilm after 1h of incubation. Taking into consideration the obtained results, we conclude that changes in the morphology of monocytes can be treated as a tool assessing the potential pathogenicity of the bacteria. What is more, the adhesive properties towards bacterial biofilm alone might be considered as a tool allowing for the assessment of the pathogenicity of the isolated strain bypassing time-consuming techniques.

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Persistence of Enterococcus faecalis in Aquatic Environments via Surface Interactions with Copepods

Applied and Environmental Microbiology ◽

10.1128/aem.71.5.2756-2761.2005 ◽

2005 ◽

Vol 71 (5) ◽

pp. 2756-2761 ◽

Cited By ~ 31

Author(s):

Caterina Signoretto ◽

Gloria Burlacchini ◽

Carla Pruzzo ◽

Pietro Canepari

Keyword(s):

Enterococcus Faecalis ◽

Microbiological Quality ◽

Lipoteichoic Acid ◽

Survival Strategies ◽

Natural Environments ◽

Human Pathogens ◽

Vbnc State ◽

Adhesive Properties ◽

Main Component

ABSTRACT Several human pathogens and fecal-pollution indicators may persist as viable organisms in natural environments, owing to their ability to activate different types of survival strategies. These strategies include adhesion on both abiotic and biotic surfaces and the entrance to the so-called viable but nonculturable (VBNC) state. In an 18-month survey for the detection of enterococci in both lake water and seawater, C. Signoretto et al. (Appl. Environ. Microbiol. 70:6892-6896, 2004) have shown that Enterococcus faecalis was detected mostly bound to plankton and in the VBNC state. In the present study, we show that in vitro adhesion of E. faecalis to copepods accelerated the entry of cells into the VBNC state relative to that of planktonic bacteria. VBNC E. faecalis cells maintained their adhesive properties to copepods and chitin (the main component of the copepod carapace), though to a reduced extent in comparison with growing cells. Sugar competition experiments showed interference with adhesion to both copepods and chitin by GlcNAc and only to copepods by d-mannose. Four enterococcal cell wall proteins present in both growing and VBNC cells and lipoteichoic acid were shown to be capable of binding chitin. The results indicate that copepods may represent an additional environmental reservoir of enterococci, thus suggesting the advisability of redesigning the protocols currently used for microbial detection during the evaluation of the microbiological quality of environmental samples.

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In vitro adhesive properties and virulence factors of Enterococcus faecalis strains

Research in Microbiology ◽

10.1016/s0923-2508(01)01291-8 ◽

2002 ◽

Vol 153 (2) ◽

pp. 75-80 ◽

Cited By ~ 52

Author(s):

Christine Archimbaud ◽

Nathan Shankar ◽

Christiane Forestier ◽

Arto Baghdayan ◽

Michael S Gilmore ◽

...

Keyword(s):

Enterococcus Faecalis ◽

Virulence Factors ◽

Adhesive Properties

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Once-versus thrice-daily netilmicin combined with amoxicillin, penicillin, or vancomycin against Enterococcus faecalis in a pharmacodynamic in vitro model.

Antimicrobial Agents and Chemotherapy ◽

10.1128/aac.40.10.2258 ◽

1996 ◽

Vol 40 (10) ◽

pp. 2258-2261 ◽

Cited By ~ 11

Author(s):

S Schwank ◽

J Blaser

Keyword(s):

Enterococcus Faecalis ◽

Half Life ◽

In Vitro Model ◽

Bacterial Biofilm ◽

In Vivo Studies ◽

Bacterial Killing ◽

Once Daily ◽

Vitro Model

Several in vitro and in vivo studies as well as clinical trials have demonstrated that once-daily aminoglycoside regimens are as effective as or more effective than multiple daily dosings. However, the most favorable aminoglycoside dosing regimen for treating enterococcal endocarditis remains controversial. The same total dose of netilmicin was administered as once-daily (24-micrograms/ml peaks) and thrice-daily (8 micrograms/ml) regimens in a pharmacodynamic in vitro model simulating exposure of Enterococcus faecalis to human serum kinetics. Netilmicin was administered in combination with continuous infusions of amoxicillin, vancomycin, or penicillin against a bacterial biofilm adhering to glass beads. No significant differences in bacterial killing were found after 24 or 48 h between the once- and thrice-daily regimens. Additional experiments considering animal kinetics (half-life of netilmicin, 20 min) instead of human kinetics (half-life, 2.5 h) in the pharmacodynamic model also revealed similar results. The addition of netilmicin synergistically increased the activity of vancomycin (P < 0.05). In contrast, amoxicillin alone was as effective as the combination with netilmicin. Thus, it could not be established in this model that once-daily dosing of aminoglycosides is contraindicated for treating infections caused by E. faecalis.

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Use of the Real Time xCelligence System for Purposes of Medical Microbiology

Polish Journal of Microbiology ◽

10.33073/pjm-2012-024 ◽

2012 ◽

Vol 61 (3) ◽

pp. 191-197 ◽

Cited By ~ 13

Author(s):

ADAM F. JUNKA ◽

ADRIANA JANCZURA ◽

DANUTA SMUTNICKA ◽

BEATA MĄCZYŃSKA ◽

ANNA SECEWICZ ◽

...

Keyword(s):

Real Time ◽

Biofilm Formation ◽

Reference Strain ◽

Morphological Changes ◽

Chinese Hamster ◽

Eukaryotic Cell ◽

Time Measurement ◽

Bacterial Biofilm ◽

Real Time Measurement

Roche's xCelligence impedance-measuring instrument is one of a few commercially available systems of such type. According to the best knowledge of authors, instrument was tested so far only for eukaryotic cell research. The aim of this work was to estimate xCELLigence suitability for the microbiological tests, including (i) measurement of morphological changes in eukaryotic cells as a result of bacterial toxin activity, (ii) measurement of bacterial biofilm formation and (iii) impact of antiseptics on the biofilm structure. To test the infuence of bacterial LT enterotoxin on eukaryotic cell lines, Chinese Hamster Ovary (CHO) cell line and reference strain Escherichia coli ATTC 35401 were used. To investigate Roche's instrument ability to measure biofilm formation and impact of antiseptics on its development, Staphylococcus aureus ATTC6538 reference strain was used. The data generated during the experiments indicate excellent ability of xCelligence instrument to detect cytopathic effect caused by bacterial LT endotoxin and to detect staphylococcal biofilm formation. However, interpretation of the results obtained during real-time measurement of antiseptic's bactericidal activity against staphylococcal biofilm, caused many difficulties. xCelligence instrument can be used for real-time monitoring of morphological changes in CHO cells treated with bacterial LT enterotoxin and for real-time measurement of staphylococcal biofilm formation in vitro. Further investigation is necessary to confirm suitability of system to analyze antiseptic's antimicrobial activity against biofilm in vitro.

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Comparison of Enterococcus faecalis Biofilm Removal Efficiency among Bacteriophage PBEF129, Its Endolysin, and Cefotaxime

Viruses ◽

10.3390/v13030426 ◽

2021 ◽

Vol 13 (3) ◽

pp. 426

Author(s):

Hyun Keun Oh ◽

Yoon Jung Hwang ◽

Hye-Won Hong ◽

Heejoon Myung

Keyword(s):

Enterococcus Faecalis ◽

Gc Content ◽

Bacterial Biofilm ◽

Open Reading Frames ◽

Base Pairs ◽

Double Stranded Dna ◽

Biofilm Removal ◽

Query Coverage ◽

Encoding Genes

Enterococcus faecalis is a Gram-positive pathogen which colonizes human intestinal surfaces, forming biofilms, and demonstrates a high resistance to many antibiotics. Especially, antibiotics are less effective for eradicating biofilms and better alternatives are needed. In this study, we have isolated and characterized a bacteriophage, PBEF129, infecting E. faecalis. PBEF129 infected a variety of strains of E. faecalis, including those exhibiting antibiotic resistance. Its genome is a linear double-stranded DNA, 144,230 base pairs in length. Its GC content is 35.9%. The closest genomic DNA sequence was found in Enterococcus phage vB_EfaM_Ef2.3, with a sequence identity of 99.06% over 95% query coverage. Furthermore, 75 open reading frames (ORFs) were functionally annotated and five tRNA-encoding genes were found. ORF 6 was annotated as a phage endolysin having an L-acetylmuramoyl-l-alanine amidase activity. We purified the enzyme as a recombinant protein and confirmed its enzymatic activity. The endolysin’s host range was observed to be wider than its parent phage PBEF129. When applied to bacterial biofilm on the surface of in vitro cultured human intestinal cells, it demonstrated a removal efficacy of the same degree as cefotaxime, but much lower than its parent bacteriophage.

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Gelatinase Contributes to the Pathogenesis of Endocarditis Caused by Enterococcus faecalis

Infection and Immunity ◽

10.1128/iai.01118-09 ◽

2010 ◽

Vol 78 (11) ◽

pp. 4936-4943 ◽

Cited By ~ 82

Author(s):

Lance R. Thurlow ◽

Vinai Chittezham Thomas ◽

Sanjeev Narayanan ◽

Sally Olson ◽

Sherry D. Fleming ◽

...

Keyword(s):

Aortic Valve ◽

Enterococcus Faecalis ◽

Complex Disease ◽

Neutrophil Migration ◽

Rabbit Model ◽

Bacterial Biofilm ◽

Pathogenic Potential ◽

Tract Infections

ABSTRACT The Gram-positive pathogen Enterococcus faecalis is a leading agent of nosocomial infections, including urinary tract infections, surgical site infections, and bacteremia. Among the infections caused by E. faecalis, endocarditis remains a serious clinical manifestation and unique in that it is commonly acquired in a community setting. Infective endocarditis is a complex disease, with many host and microbial components contributing to the formation of bacterial biofilm-like vegetations on the aortic valve and adjacent areas within the heart. In the current study, we compared the pathogenic potential of the vancomycin-resistant E. faecalis V583 and three isogenic protease mutants (ΔgelE, ΔsprE, and ΔgelE ΔsprE mutants) in a rabbit model of enterococcal endocarditis. The bacterial burdens displayed by GelE− mutants (ΔgelE and ΔgelE ΔsprE mutants) in the heart were significantly lower than those of V583 or the SprE− mutant. Vegetations on the aortic valve infected with GelE− mutants (ΔgelE and ΔgelE ΔsprE mutants) also showed a significant increase in deposition of fibrinous matrix layer and increased chemotaxis of inflammatory cells. In support of a role for proteolytic modulation of the immune response to E. faecalis, we also demonstrate that GelE can cleave the anaphylatoxin complement C5a and that this proteolysis leads to decreased neutrophil migration in vitro. In vivo, a decreased heterophil (neutrophil-like cell) migration was observed at tissue sites infected with GelE-producing strains but not at those infected with SprE-producing strains. Taken together, these observations suggest that of the two enterococcal proteases, gelatinase is the principal mediator of pathogenesis in endocarditis.

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The Effect of Pluchea indica Less Leaves Extract Againts Biofilm of Enterococcus faecalis and Fusobacterium nucleatum In Vitro

DENTA ◽

10.30649/denta.v11i1.125 ◽

2017 ◽

Vol 11 (1) ◽

pp. 51

Author(s):

Agni Febrina Pargaputri ◽

Elly Munadziroh ◽

Retno Indrawati

Keyword(s):

Enterococcus Faecalis ◽

Root Canal ◽

Biofilm Formation ◽

Chemical Properties ◽

Fusobacterium Nucleatum ◽

Bacterial Biofilm ◽

Dilution Method ◽

Infected Root ◽

Infected Root Canal

Background: Enterococcus faecalis and Fusobacterium nucleatum are the most common bacteria found in infected root canal teeth and most of them often caused failure in endodontic treatments. These bacteria can form biofilm which makes them more resistant against antibacterial agents. Biofilm formation also causes a decrease in antibiotics and antimicrobials sensitivity. Pluchea indica Less leaves is a species of plants that has several chemical properties. It consists of flavonoids and polyphenols which have benefits to inhibit biofilm formation. Because of its benefits, the extract of Pluchea indica Less leaves can be potentially developed as one of sterilization dressing in root canal teeth. Purpose: The aim of this study was to determine biofilm formation inhibition of Pluchea indica Less leaves extract against Enterococcus faecalis and Fusobacterium nucleatum. Materials and Methods: The dilution method was done first to show the Minimum Inhibitory Concentration (MIC) of the extract. The inhibition biolfilm formation was tested using microtitter plate assay by measuring the bacterial biofilm Optical Density (OD) from ELISA reader’s results and using autoagregation assay to show the inhibition of adherance bacteria. The Pluchea indica Less leaves extract concentration used for inhibition of biofilm formation were 100%, 50%, 25%, 12,5%, and 6,25%. Results: The result of biofilm formation inhibition showed that Pluchea indica Less leaves extract were able to inhibit Enterococcus faecalis and Fusobacterium nucleatum’ biofilm formation with strong moderate effect. The autoagregation assay showed a decrease in autoagregation percentation of Enterococcus faecalis and Fusobacterium nucleatum. Conclusions: Pluchea indica Less leaves extract has effect to inhibit biofilm formation of Enterococcus faecalis and Fusobacterium nucleatum.Keywords: Pluchea indica Less leaves extract, Enterococcus faecalis, Fusobacterium nucleatum, biofilm.Correspondence: Agni Febrina Pargaputri, Department of Oral Biology, Faculty of Dentistry, Hang Tuah University, Arif Rahman Hakim 150, Surabaya, Phone.031-5912191, Email: [email protected]

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Development of an intracanal mature Enterococcus faecalis biofilm and its susceptibility to some antimicrobial intracanal medications; an in vitro study

European Journal of Dentistry ◽

10.1055/s-0039-1698929 ◽

2012 ◽

Vol 06 (01) ◽

pp. 043-050 ◽

Cited By ~ 11

Author(s):

Shehab El-Din Mohamed Saber ◽

Soha A El-Hady

Keyword(s):

Calcium Hydroxide ◽

Enterococcus Faecalis ◽

Chemotherapeutic Agents ◽

Bacterial Biofilm ◽

Sensitivity Testing ◽

Amoxicillin Clavulanate ◽

Biofilm Bacteria ◽

Biofilm Development ◽

Better Than

ABSTRACTObjectives: To develop a mature biofilm of Enterococcus faecalis inside the root canal system and to test its susceptibility to some antimicrobial medications in vitro.Methods: Single rooted premolars were mechanically enlarged, sterilized, and then infected with a clinical isolate of E. faecalis. Biofilm formation and maturation was monitored using SEM. Biofilm bacteria were exposed to Amoxicillin+clavulanate, Ciprofloxacin, Clindamycin, Doxycycline, and calcium hydroxide as intracanal medications for 1 week. Finally bacterial samples were collected, and colony-forming units were enumerated.Results: SEM examination confirmed the formation of a mature biofilm at the end of the incubation period. All the chemotherapeutic agents used were significantly better than Calcium hydroxide in elimination of biofilm bacteria. The antimicrobial effect of Amoxicillin + clavulanate, Ciprofloxacin and Clindamycin was significantly better than Doxycycline (P=.05). However the difference in the antimicrobial effectiveness among them was statistically non-significant (P=.05).Conclusions: The method used for bacterial biofilm development and maturation is reliable and can be used to assess the anti bacterial potential of endodontic materials. Also, the local application of antibacterial agents can be beneficial in resistant cases of apical periodontitis but only after careful culture and sensitivity testing to choose the appropriate agent for the existing flora. (Eur J Dent 2012;6:43-50)

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Correlation Between Cellular Functions and Morphological Changes of Human Trophoblast in Vitro

Proceedings, annual meeting, Electron Microscopy Society of America ◽

10.1017/s0424820100116620 ◽

1975 ◽

Vol 33 ◽

pp. 600-601

Author(s):

John C. Garancis ◽

Robert O. Hussa ◽

Michael T. Story ◽

Donald Yorde ◽

Roland A. Pattillo

Keyword(s):

Electron Microscopy ◽

Cellular Proliferation ◽

Morphological Changes ◽

Culture Fluid ◽

Cellular Functions ◽

Human Trophoblast ◽

Transmission Electron ◽

Marked Activity ◽

Malignant Trophoblast

Human malignant trophoblast cells in continuous culture were incubated for 3 days in medium containing 1 mM N6-O2'-dibutyryl cyclic adenosine 3':5'-monophosphate (dibutyryl cyclic AMP) and 1 mM theophylline. The culture fluid was replenished daily. Stimulated cultures secreted many times more chorionic gonadotropin and estrogens than did control cultures in the absence of increased cellular proliferation. Scanning electron microscopy revealed remarkable surface changes of stimulated cells. Control cells (not stimulated) were smooth or provided with varying numbers of microvilli (Fig. 1). The latter, usually, were short and thin. The surface features of stimulated cells were considerably different. There was marked increase of microvilli which appeared elongated and thick. Many cells were covered with confluent polypoid projections (Fig. 2). Transmission electron microscopy demonstrated marked activity of cytoplasmic organelles. Mitochondria were increased in number and size; some giant forms with numerous cristae were observed.

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Ultrastructural studies on the interaction of haemophilus influenzae with human endothelial cells in vitro

Proceedings, annual meeting, Electron Microscopy Society of America ◽

10.1017/s042482010016073x ◽

1990 ◽

Vol 48 (3) ◽

pp. 636-637

Author(s):

D.J.P. Ferguson ◽

M. Virji ◽

H. Kayhty ◽

E.R. Moxon

Keyword(s):

Endothelial Cells ◽

Haemophilus Influenzae ◽

Intercellular Junctions ◽

Blood Stream ◽

Ultrastructural Studies ◽

Endothelial Barriers ◽

Serotype B ◽

Meningitis In Children ◽

Respiratory Epithelial

Haemophilus influenzae is a human pathogen which causes meningitis in children. Systemic H. influenzae infection is largely confined to encapsulated serotype b organisms and is a major cause of meningitis in the U.K. and elsewhere. However, the pathogenesis of the disease is still poorly understood. Studies in the infant rat model, in which intranasal challenge results in bacteraemia, have shown that H. influenzae enters submucosal tissues and disseminates to the blood stream within minutes. The rapidity of these events suggests that H. influenzae penetrates both respiratory epithelial and endothelial barriers with great efficiency. It is not known whether the bacteria penetrate via the intercellular junctions, are translocated within the cells or carried across the cellular barrier in 'trojan horse' fashion within phagocytes. In the present studies, we have challenged cultured human umbilical cord_vein endothelial cells (HUVECs) with both capsulated (b+) and capsule-deficient (b-) isogenic variants of one strain of H. influenzae in order to investigate the interaction between the bacteria and HUVEC and the effect of the capsule.

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