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Status unknownNCT05751317Updated Apr 19, 2023

Phenotypic and Genotypic Variations of Enterococcus Spp

An observational study in Isolation of Enterococci From Samples, Demonstration of Enterococci Antibiotic Susceptibility and Detection of Strains Enterococci Produce Biofilm, sponsored by Sohag University. Status unknown at 1 site in Egypt. Open to participants aged 1 Month to 90 Years. Per ClinicalTrials.gov, last updated 2023-04-19.

Sponsored by Sohag University · Observational

The sponsor has not verified this record recently (last verified Apr 2023), so the status shown — last known as Recruiting — may be out of date.
Study type
Observational
Model
Case-control
Time perspective
Cross-sectional
Enrollment
100
Ages
1 Month to 90 Years
Sex
All
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Study summary

Enterococci are Gram-positive facultative anaerobic cocci arranged in short and medium chains. Enterococci reside in the gastrointestinal tract and usually function commensally with humans. They can, however, cause several infections, such as urinary tract infections (UTIs), intra-abdominal infection, bacteremia, or endocarditis.

Among many species identified, E. faecalis and E. faecium are the most common species capable of causing infection and posing a threat of antimicrobial resistance, with E. faecalis accounting for the majority of infections.

Read the detailed description

Enterococci are Gram-positive facultative anaerobic cocci arranged in short and medium chains.

Enterococci reside in the gastrointestinal tract and usually function commensally with humans. They can, however, cause several infections, such as urinary tract infections (UTIs), intra-abdominal infection, bacteremia, or endocarditis.

Among many species identified, E. faecalis and E. faecium are the most common species capable of causing infection and posing a threat of antimicrobial resistance, with E. faecalis accounting for the majority of infections.

Pathogenic species of enterococci express many virulence factors such as adhesins, gelatinase, Enterococcus surface protein, aggregation substances and cytolysins along with biofilm formation. These factors enhance the ability of the pathogen to invade, attach and survive through the acquisition of nutrients in the host tissue. Their presence in drug resistant strains increases the severity of the infection

Enterococci are intrinsically resistant to antibiotics such as aminoglycosides and β-lactam-based antibiotics. Moderate resistance to aminoglycosides is due to the intrinsic low permeability of the enterococcal cell wall to the large aminoglycoside molecules and is more prevalent in E. faecium than E. faecalis. Intrinsic β-lactam resistance is due to the overexpression of penicillin-binding proteins with low affinity for β-lactams, which makes E. faecalis more resistant to penicillin than E. faecium

Moreover, enterococci can readily acquire resistance to antimicrobials, and vancomycin-resistant enterococci (VRE) are among the priority pathogens for which new antibiotics are needed.

In addition, biofilm formation is one of the strategies for the enterococci to evade the host's immune response and the inhibitory or killing effects of antibiotics.

This self-produced extracellular matrix also provides a suitable microenvironment for enterococci to grow and facilitates the transmission of mobile genetic elements (MGEs) between bacteria. Enterococcal biofilms have been implicated in indwelling device-related infections such as prosthetic valve endocarditis, prosthetic joint infections and catheter-related infections.

Biofilm forming bacteria show resistance to many antibiotics and immune response which results in treatment failure. Given the difficulty of treating and eradicating biofilm associated infections, there is an unmet need for therapeutic options other than antibiotics to prevent biofilm formation.

Nanoparticles are attracting attention given their very small size and various antibacterial properties. Nanoparticles can interact with bacteria per unit area, which can make the antibacterial activity of nanoparticles more powerful. Nanoparticles can also initiate several bactericidal pathways, such as disrupting the bacterial membrane and release of intracellular components, making it difficult for bacteria to become resistant.

02

Conditions studied

  • Isolation of Enterococci From Samples
  • Demonstration of Enterococci Antibiotic Susceptibility
  • Detection of Strains Enterococci Produce Biofilm
  • Studying Effect of Nanoparticles on Enterococci Antimicrobial Resistance
  • Studying Effect of Nanoparticles on Enterococci Biofilm
  • Genotyping of Enterococci

Keywords

  • phenotypic
  • genotypic
  • Enterococci
  • biofilm
03

In context

Disease Susceptibility

141 studies on the registry are indexed under Disease Susceptibility; 31 are open to participants now.

This study's planned enrollment of 100 is below the median of 200 across 84 observational studies indexed under Disease Susceptibility.

Browse Disease Susceptibility studies →

Lead sponsor

Sohag University is the lead sponsor of 1,183 studies on the registry; 612 are open to participants now.

Counted across the registry records on this site, refreshed daily.

04

Who can participate

Ages eligible
1 Month to 90 Years
Sexes eligible
All
Sampling method
Non-probability sample

Study population

All the selected patients will be subjected to complete history taking (personal, clinical, associated comorbidities, history of drug intake, and length of hospital stay before sampling).

* Collected samples will be transported to the Medical Microbiology and Immunology research laboratory as soon as possible.

Inclusion criteria

  • All patients suffering from infections that can be caused by Enterococci.

Exclusion criteria

Exclusion Criteria:

  • All patients suffering from infections that aren't caused by Enterococci
05

Study design

Observational model
Case-control
Time perspective
Cross-sectional
Enrollment
100 participants (estimated)
Patient registry
No
Biospecimen retention
Samples with dna

Groups and cohorts

  • samples containing Enterococci

    Isolates of Enterococci will be identified by Gram staining, colony morphology, catalase test, and growth on Bile Esculin agar. All isolates will be identified to species level using Vitek2 automated system Strains confirmed as Enterococci will be examined for their antibiotic susceptibility by modified Kirby Bauer's disc diffusion method on MuellerHinton Agar. The biofilm formation activity of Enterococci isolates will be tested using the microtiter plate technique Detection of the effect of nanoparticles on the antibiotic susceptibility profile of Enterococci. Detection of the effect of nanoparticles on the biofilm producing Enterococci. Molecular identification of some virulence factors genes and antibiotic resistance genes of Enterococci using PCR

    Diagnostic Test: Culture · Diagnostic Test: Staining: · Diagnostic Test: Biochemical reactions: · Diagnostic Test: VITEK · Diagnostic Test: Antibiotic sensitivity test · Diagnostic Test: nanoparticles effect · Diagnostic Test: The biofilm formation activity · Diagnostic Test: molecular diagnosis

  • samples with bacteria other than enterococci

    Diagnostic Test: Culture · Diagnostic Test: Staining: · Diagnostic Test: Biochemical reactions: · Diagnostic Test: VITEK

Interventions

  • Diagnostic testCulture

    * Samples will be transported to Medical Microbiology and Immunology Laboratory and will be inoculated on MacConkey medium. * Pink colonies will be inoculated on bile esculin agar medium. * Enterococci produce blackening of the agar

  • Diagnostic testStaining:

    The growing colonies on bile esculin agar medium will be examined microscopically after staining by Gram stain.

  • Diagnostic testBiochemical reactions:

    * Catalase test. * Salt tolerance test

  • Diagnostic testVITEK

    Automated identification of Enterococci will be done with VITEK2 system.

  • Diagnostic testAntibiotic sensitivity test

    Strains confirmed as Enterococci will be examined for their antibiotic susceptibility by modified Kirby Bauer's disc diffusion method on Mueller-Hinton Agar.

  • Diagnostic testnanoparticles effect

    The effect of nanoparticles on Enterococci antimicrobial resistance pattern

  • Diagnostic testThe biofilm formation activity

    The biofilm formation activity of Enterococci isolates will be tested using the microtiter plate technique

  • Diagnostic testmolecular diagnosis

    Molecular identification of some virulence factors genes and antibiotic resistance genes of Enterococci using PCR

06

What researchers measure

Primary outcomes

  1. Isolation and identification of Enterococci from different clinical samples

    Isolation and identification of Enterococci from different clinical samples (pus, urine, urinary catheter samples, stool, wound swabs, sputum, central venous catheter samples) will be collected under aseptic precautions from patients admitted at different departments at Sohag university hospitals.

    Time frame: from April 2023 to December 2023

  2. Demonstration of Enterococci antibiotic susceptibility profile

    Strains confirmed as Enterococci will be examined for their antibiotic susceptibility by modified Kirby Bauer's disc diffusion method on Mueller-Hinton Agar.

    Time frame: from April 2023 to December 2023

  3. Detection of strains of Enterococci which produce biofilm

    The biofilm formation activity of Enterococci isolates will be tested using the microtiter plate technique

    Time frame: from April 2023 to December 2023

  4. Studying the effect of nanoparticles on Enterococci antimicrobial resistance pattern

    Inhibition zones of all groups will be compared to detect the effect of nanoparticles on Enterococci antimicrobial resistance pattern.

    Time frame: from April 2023 to December 2023

  5. Studying the effect of nanoparticles on Enterococci biofilm producing ability

    The effect of nanoparticles on Enterococci biofilm producing ability

    Time frame: from December 2023 to March 2024

  6. Genotypic characterization of Enterococci.

    Molecular identification of some virulence factors genes and antibiotic resistance genes of Enterococci using polymerase chain reaction.

    Time frame: rom December 2023 to March 2024

07

Study locations

1 of 1 sites recruiting
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References and documents

Publications

  • Ferguson DM, Talavera GN, Hernandez LA, Weisberg SB, Ambrose RF, Jay JA. Virulence Genes among Enterococcus faecalis and Enterococcus faecium Isolated from Coastal Beaches and Human and Nonhuman Sources in Southern California and Puerto Rico. J Pathog. 2016;2016:3437214. doi: 10.1155/2016/3437214. Epub 2016 Apr 10. PubMed 27144029 ↗

Individual participant data

Plan to share: No

09

Updates

Tracking since Sep 25, 2026
No changes since tracking began. The registry record was last updated on Apr 19, 2023, before this site started recording changes on Sep 25, 2026. Its history is on ClinicalTrials.gov ↗
10

Registry details

Key details

Study ID
NCT05751317
Lead sponsor
Sohag University
Responsible party
Mai Gamal Abdel Naser Abbas Khalifa (principal investigator, Sohag University) — Principal investigator
First posted
Mar 2, 2023
Start date
Apr 1, 2023
Primary completion
Dec 31, 2023 (estimated)
Completion
Mar 30, 2024 (estimated)
Last update
Apr 19, 2023

Study contacts

Mai G Abbas, Demonstrator
Contact
maigamal@med.sohag.edu.eg
01068298408
Noha S Shafik, Lecturer
Contact
nohasaber@med.sohag.edu.eg
01067261504
Mona F Mohamed, professor
study chair · Sohag University
Wesam A Abu El wafa
study chair · Sohag University

Oversight

Data monitoring committee
Yes
FDA-regulated drug
No
FDA-regulated device
No
View the source record on ClinicalTrials.gov ↗

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This study is status unknown, as verified in Apr 2023. You cannot join it, but the record below documents what was studied.

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