Microbiome and Association With Implant Infections: Investigating the Impact of Antibiotics on the Gut and Breast Microbiomes Post-mastectomy With Implant-based Breast Reconstruction
Summary
The most common tissue expander-related infections are from Staphylococcus and Pseudomonas species. In addition, from breast tissue microbiome studies, Staphylococcus and Pseudomonas show variable abundance across samples. The investigator hypothesizes that participants undergoing mastectomy with high initial abundance of Staphylococcus and/or Pseudomonas are more likely to develop subsequent tissue expander-related infections from these respective organisms.
Detailed description
PRIMARY OBJECTIVE: I. To determine the feasibility of breast microbiome sampling using the study techniques SECONDARY OBJECTIVES: I. To define the differences in the gut and breast microbiomes between participants undergoing mastectomy with implant-based reconstruction who develop post-operative implant infection and those who do not. II. To determine the effects of post-operative antibiotics on the gut and breast microbiomes after mastectomy with implant-based reconstruction. OUTLINE: Participants are randomized to 1 of 2 cohorts. COHORT A: Participants receive postoperative antibiotics to take for at least 7 days post-operatively. COHORT B: Participants receive no antibiotics post-operatively in the absence of clinical evidence of infection. Participants are followed up for 90 days.
Arms & interventions
- DrugCephalexin
Given orally (PO)
Outcome measures
Primary
Proportion of tissue samples obtained successfully over time
The feasibility of success in obtaining samples from breast tissue will be measured as a binary outcome (successful or not successful) over time (intra-operatively, week 1, week 2, week 3, and week 4). The investigators will assess and document success in obtaining a tissue sample immediately at the time of sampling of each participant.
Time frame: 90 days
Proportion of aspirate samples obtained successfully overall
The feasibility of success in obtaining samples from the tissue expander aspiration ports will be measured as a binary outcome (successful or not successful) over time (intra-operatively, week 1, week 2, week 3, and week 4). The investigators will assess and document success in obtaining a aspirate sample immediately at the time of sampling of each participant.
Time frame: 90 days
Proportion of tissue samples successfully producing microbiome data
Feasibility based off of the success rates in producing microbiome data from tissue samples in each patient will be measured as a binary outcome (successful or not successful) and will be reported.
Time frame: 90 days
Proportion of aspirate samples successfully producing microbiome data
Feasibility based off of the success rates in producing microbiome data from tissue samples in each patient will be measured as a binary outcome (successful or not successful) and will be reported.
Time frame: 90 days
Proportion of any samples successfully producing microbiome data
Feasibility based off of the success rates in producing microbiome data from tissue or aspirate samples in each patient will be measured as a binary outcome (successful or not successful) and will be reported.
Time frame: 90 days
Correlation of the change in breast microbiome over time with total duration of antibiotics (Cohort A only)
The investigators will analyze the microbiomes between groups, between microbiome environments (gut v. breast, inter-individual). The correlate of change in breast microbiome over time will be compared to the total duration of antibiotics for Cohort A only. The measure of association ranges from +1 to -1, with a value of zero equal to no association.
Time frame: 90 days
Secondary
Proportion of participants with post-operative infection
Time frame: 90 days
Shannon Diversity Index Score for species of microbiome
Time frame: 90 days
Number of overall identified microbes
Time frame: 90 days
Eligibility criteria
Study locations (1)
University of California, San Francisco
San Francisco, California, 94143