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Changes in Resistome After Dental Extraction and Amoxicillin.

The safety and scientific validity of this study is the responsibility of the study sponsor and investigators. Listing a study does not mean it has been evaluated by the U.S. Federal Government. Read our disclaimer for details. Identifier: NCT02830347
Recruitment Status : Unknown
Verified July 2016 by Dr Michael G. Botelho, The University of Hong Kong.
Recruitment status was:  Active, not recruiting
First Posted : July 12, 2016
Last Update Posted : October 27, 2017
Information provided by (Responsible Party):
Dr Michael G. Botelho, The University of Hong Kong

Brief Summary:

The aim of this study is to evaluate the nature of the change in oral and gut bacterial resistance profiles after antibiotic therapy for a surgical procedure in two groups. The intervention group will receive a course of amoxicillin and analgesics after surgical extraction and have bacterial samples taken from saliva, tongue coatings and stool samples at four appointments over a period of six months. This will be compared to the control group which receive only analgesics after the surgical extraction.

An examination of the development and sustainability of antibiotic resistance in the oral and gut microbiome of healthy cohorts will be followed up for 6 months, after surgical extraction of impacted teeth.

Change in proportion of antibiotic resistant bacterial components will be studied using Metagenomic DNA sequencing and quantification of resistant genes .

Condition or disease Intervention/treatment
Impacted Third Molar Tooth Drug: Amoxicillin Procedure: Extraction

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Study Type : Observational
Estimated Enrollment : 16 participants
Observational Model: Cohort
Time Perspective: Prospective
Official Title: Evaluation of the Changes in Oral and Gut Bacterial Resistance Caused by Short Term Antibiotic Treatment Following a Surgical Dental Procedure - A Prospective Clinical Study.
Study Start Date : June 2015
Estimated Primary Completion Date : March 2018
Estimated Study Completion Date : March 2018

Resource links provided by the National Library of Medicine

MedlinePlus related topics: Antibiotics

Group/Cohort Intervention/treatment
No randomization is performed. Patients who are prescribed antibiotics by the clinician performing the tooth extraction ( based on case complexity and intra operative judgement) are recruited into this group.The principal investigator is not involved in the decision to prescribe antibiotics or not.
Drug: Amoxicillin
Other Name: Aroxin

Procedure: Extraction
Extraction of third molars

No Amoxicillin
Patients who do not receive antibiotics after extractions are recruited into this group.
Procedure: Extraction
Extraction of third molars

Primary Outcome Measures :
  1. Quantification of antibiotic resistance genes by Resistance genes output at each timepoint from HUmanN 1.0 .Validation by QPCR values for Blatem and erm genes at each timepoint. [ Time Frame: Baseline,One week,One month,Six months ]

    Resistome analysis Changes in the (relative) concentration of total resistance genes (the resistome) in the metagenomic DNA sequences will be analyzed as follows: Antibiotic resistance genes will be downloaded from the Antibiotic Resistance Genes Database (20). The downloaded dataset (ardbAnno1.0), containing 7828 entries, will be made non-redundant first and UBLAST from USEARCH v7.0.1090 (20) will be used to map the reads to the (ARDB) proteins (E-value threshold 10, post-filtered to include hits with a maximum E-value of 1E-10 inclusive).

    The results will be processed with HUMAN (21) to assign weights to the proteins. These weights were then normalized by dividing by the total number of filtered (non-human) reads, and summarized per antibiotic resistance type in the resistome. Next, fold changes will calculated for all resistance types with a baseline weight larger than 1E-8.

Biospecimen Retention:   Samples With DNA


Toungue coatings

Stool samples

Information from the National Library of Medicine

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Ages Eligible for Study:   18 Years to 45 Years   (Adult)
Sexes Eligible for Study:   All
Accepts Healthy Volunteers:   Yes
Sampling Method:   Non-Probability Sample
Study Population

Patients will be recruited from the waiting list from the Prince Philip Dental Hospital, Subjects scheduled for third molar extraction will be recruited based on the inclusion and exclusion criteria, provided they give a written informed consent for the acquisition of Saliva, tongue coatings and stool samples at the specified time points, after the study design and objectives have been explained in detail by the investigator.

The prescription of antibiotics will be based on clinical judgment based on case complexity and the extent of the surgical trauma intra-operative Group 1- Surgical extraction with antibiotics-Amoxicillin 250 mg three times daily for 5 days and analgesics for pain relief.

Group 2- Surgical extraction without antibiotics- Only analgesics for pain relief


Inclusion Criteria:

  1. Men and women aged between 18 and 45 years
  2. Subjects who are scheduled to have a surgical tooth extraction.
  3. Subjects who have signed an informed consent after being informed of the study design, objectives and, risks/benefits
  4. No history of use of antibiotics up to three months prior to participation in the study.
  5. No medical condition that prevents the surgical procedure or antibiotic therapy.
  6. No history of hypersensitivity to beta lactams.
  7. No contraindication to amoxicillin therapy.
  8. Subjects are not pregnant or currently breast feeding.
  9. No known or suspected immunodeficiency.

Exclusion Criteria:

  1. History of antibiotic use within 3 months from baseline evaluation.
  2. Any medical condition that prevents the surgical procedure or antibiotic therapy.
  3. History of hypersensitivity to beta lactams
  4. Contraindication for amoxicillin therapy
  5. Pregnant or breast feeding women.
  6. Subjects with known or suspected immunodeficiency.
  7. Caries active subjects defined as subjects with active caries involving more than 3 teeth.
  8. Subjects diagnosed with chronic periodontitis.
  9. Subjects regularly using an antibacterial mouth rinse or planning to use one after the extraction.

Information from the National Library of Medicine

To learn more about this study, you or your doctor may contact the study research staff using the contact information provided by the sponsor.

Please refer to this study by its identifier (NCT number): NCT02830347

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Oral Rehabilitation, Faculty of Dentistry, The University of Hong Kong
Hong Kong, China
Sponsors and Collaborators
The University of Hong Kong
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Principal Investigator: Michael G Botelho, BDS MSc PhD The University of Hong Kong

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Responsible Party: Dr Michael G. Botelho, Clinical Associate Professor, The University of Hong Kong Identifier: NCT02830347    
Other Study ID Numbers: Version 1.1 (22.4.15)
First Posted: July 12, 2016    Key Record Dates
Last Update Posted: October 27, 2017
Last Verified: July 2016
Individual Participant Data (IPD) Sharing Statement:
Plan to Share IPD: Yes
Plan Description: Deidentified patient data will be published within 6 months of the study completion.
Keywords provided by Dr Michael G. Botelho, The University of Hong Kong:
antibiotic resistance
oral microbiome
Additional relevant MeSH terms:
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Tooth, Impacted
Tooth Diseases
Stomatognathic Diseases
Anti-Bacterial Agents
Antibiotics, Antitubercular
Anti-Infective Agents
Antitubercular Agents