M. Avium WGS During Mav-PD Treatment

Longitudinal Assessment of Clinical Pulmonary Mycobacterium Avium Isolates in Treated Patients Using Whole Genome Sequencing

This is a prospective observational study using whole genome sequencing (WGS) to investigate whether new strains (other than the initially identified strain(s)) of M. avium are responsible for persistently culture positive sputum during treatment (refractory disease), or the reversion to culture positive sputum after prior conversion to negative. The study will further investigate for differences between participants living in the Toronto/York region versus participants living elsewhere.

The primary goal of this prospective observational study is to understand why some patients with M. avium lung disease have persistent or recurrent M. avium in their sputum despite treatment. The aim is to understand whether it is usually due to treatment failure or new infection.

Study Overview

• Status: Recruiting
• Conditions: Respiratory Tract Diseases; Mycobacterium Infections; Mycobacterium Infections, Nontuberculous; Nontuberculous Mycobacterial Lung Disease; Mycobacterium Avium
• Intervention / Treatment: Other: Whole genome sequencing testing

Detailed Description

Mycobacterium Avium complex (MAC) are a subset of nontuberculous mycobacteria (NTM) that are typically found in the soil and water and can cause pulmonary lung disease. Treatment of MAC is challenging as it typically requires the use of three or more antibiotics for over a long period of time and the rate of eradication is suboptimal.

Mac-WGS is an observational study that aims to understand whether new strains of M. avium are responsible for persistently culture-positive sputum during treatment. Whole genome sequencing (WGS) will be performed on M. avium isolates from the sputum of patients with Mav-PD, over the duration of the study. Additionally, home environmental samples will be collected and sequenced to identify any home source of infection.

As an observational study, participants will receive routine standard of care treatment as per discretion of the physician. Standard of care includes monthly sputum submissions. The M. avium isolated from the sputum before treatment and every three months while on treatment (until such time that the sputum becomes culture-negative) will be analyzed by WGS. If sputum becomes culture-positive again, the isolated germ will also be analyzed by whole genome sequencing. It will be determined whether the identical strain of M. avium is always present or whether more than one strain is present which would suggest either multi-strain infection or the acquisition of new strains of M. avium while on treatment. Additionally, participant's home environmental samples (i.e. faucets and showerhead biofilms) will be cultured to determine whether M. avium can be recovered and if so, it will be analyzed with WGS to assess whether it is the same strain as in the participant's sputum.

• Study Type: Observational
• Enrollment (Estimated): 40

Contacts and Locations

• Study Contact: Name: Theodore Marras, MD; Phone Number: 416-603-5767; Email: ted.marras@uhn.ca
• Study Contact Backup: Name: Matty Mehrabi, BSc, M.Ed; Phone Number: 416-603-5726; Email: matty.mehrabi@uhn.ca

Study Locations

• Canada
  • Ontario
    • Toronto, Ontario, Canada, M5G
      • Recruiting
      • University Health Network
      • Principal Investigator: Theodore Marras, MD
      • Contact: Matty Mehrabi, B.Sc. M. Ed; Phone Number: 416-603-5726; Email: matty.mehrabi@uhn.ca

Participation Criteria

Eligibility Criteria

• Ages Eligible for Study: Adult; Older Adult
• Accepts Healthy Volunteers: N/A

• Sampling Method: Non-Probability Sample

Study Population

Patients at the Toronto Western Hospital (TWH) Nontuberculous Mycobacterial (NTM) clinic who are to be initiated on therapy for Mav-PD.

Description

Inclusion Criteria:

• Age 18 and older
• Willing to provide informed consent and participate in study procedures
• Residing continuously in Ontario during the past five years
• Mav-PD, either initial or recurrent (previously treated patients will be eligible) five years
• Meet American Thoracic Society (ATS) / Infectious Diseases Society of America (IDSA) NTM disease criteria for Mav-PD

Exclusion Criteria:

• Lack of an available pre-treatment M. avium isolate in the PHOL isolate bank
• The inability to produce sputum either spontaneously or by induction with nebulized hypertonic saline
• Cavitation >3 cm internal diameter
• Known macrolide-resistant MAC infection
• HIV infection
• Known diagnosis of cystic fibrosis
• History of solid organ or hematological transplantation
• Severe comorbid illness that is reasonably expected to limit survival to <24 months
• Residing in mid/north York region (King, Aurora, Newmarket, Whitechurch-Stouffville, East Gwillimbury or Georgina)
• Having moved between regions (Toronto/southern York region vs non-Toronto/York region vs mid-northern York region) within the past 5 years

Study Plan

How is the study designed?

What is the study measuring?

Primary Outcome Measures

Outcome Measure	Measure Description	Time Frame
Proportion of patients with persistent culture-positive sputum despite antimicrobial therapy	Whole genome sequencing	24 months

Secondary Outcome Measures

Outcome Measure	Measure Description	Time Frame
Whether patients with Mav-PD have evidence of polyclonal infection as demonstrated by the presence of >1 strain of M. avium in the pre-treatment sputum or a sputum sample during treatment	Whole genome sequencing	24 months
Whether there is a source of infection from the home water environment	M. avium strains from sputum and home water source samples will determined through WGS analysis.	24 months

Collaborators and Investigators

• Sponsor: University Health Network, Toronto
• Collaborators: Western University, Canada; Public Health Ontario Laboratory, Canada
• Investigators: Principal Investigator: Theodore Marras, MD, UHN

Study record dates

Study Major Dates

• Study Start (Actual): May 13, 2024
• Primary Completion (Estimated): September 1, 2026
• Study Completion (Estimated): September 1, 2026

Study Registration Dates

• First Submitted: December 27, 2023
• First Submitted That Met QC Criteria: February 16, 2024
• First Posted (Actual): February 20, 2024

Study Record Updates

• Last Update Posted (Actual): May 21, 2024
• Last Update Submitted That Met QC Criteria: May 17, 2024
• Last Verified: May 1, 2024

More Information

Terms related to this study

• Keywords: Whole genome sequencing; Nontuberculous mycobacterium; Mycobacterium avium
• Additional Relevant MeSH Terms: Pathologic Processes; Disease Attributes; Bacterial Infections; Bacterial Infections and Mycoses; Gram-Positive Bacterial Infections; Actinomycetales Infections; Lung Diseases; Infections; Communicable Diseases; Mycobacterium Infections; Mycobacterium avium-intracellulare Infection; Respiratory Tract Diseases; Mycobacterium Infections, Nontuberculous
• Other Study ID Numbers: Mav-WGS

Drug and device information, study documents

• Studies a U.S. FDA-regulated drug product: No
• Studies a U.S. FDA-regulated device product: No