Lower Recovery of Nontuberculous Mycobacteria from Outdoor Hawai’i Environmental Water Biofilms Compared to Indoor Samples

Abstract

Nontuberculous mycobacteria (NTM) are environmental organisms that can cause opportunistic pulmonary disease with species diversity showing significant regional variation. In the United States, Hawai’i shows the highest rate of NTM pulmonary disease. The need for improved understanding of NTM reservoirs led us to identify NTM from patient respiratory specimens and compare NTM diversity between outdoor and indoor locations in Hawai’i. A total of 545 water biofilm samples were collected from 357 unique locations across Kaua’i (n = 51), O’ahu (n = 202), Maui (n = 159), and Hawai’i Island (n = 133) and divided into outdoor (n = 179) or indoor (n = 366) categories. rpoB sequence analysis was used to determine NTM species and predictive modeling applied to develop NTM risk maps based on geographic characteristics between environments. M. chimaera was frequently identified from respiratory and environmental samples followed by M. chelonae and M. abscessus; yet significantly less NTM were consistently recovered from outdoor compared to indoor biofilms, as exemplified by showerhead biofilm samples. While the frequency of M. chimaera recovery was comparable between outdoor and indoor showerhead biofilms, phylogenetic analyses demonstrate similar rpoB gene sequences between all showerhead and respiratory M. chimaera isolates, supporting outdoor and indoor environments as possible sources for pulmonary M. chimaera infections.

Healthcare-associated links in transmission of nontuberculous mycobacteria among people with cystic fibrosis (HALT NTM) study: Rationale and study design

“…In common spaces within the healthcare system, one sample will be obtained from each water source including water dispensers, ice machines, drinking fountains, patient-utilized coffee machines, and decorative water features as well as one dust sample from a vent. Environmental healthcare-associated dust and water biofilms will be selectively cultured for NTM using standard microbiological approaches as described [ 34 ]. Genomic DNA will be extracted from bacterial pellets [ 35 ] and isolates recovered will be identified to the species or subspecies level through amplification and sequencing of the RNA polymenrase beta subunit ( rpo B) gene as described [ 7 , 34 , 36 ].…”

“…Environmental healthcare-associated dust and water biofilms will be selectively cultured for NTM using standard microbiological approaches as described [ 34 ]. Genomic DNA will be extracted from bacterial pellets [ 35 ] and isolates recovered will be identified to the species or subspecies level through amplification and sequencing of the RNA polymenrase beta subunit ( rpo B) gene as described [ 7 , 34 , 36 ]. Clinically-relevant NTM that are also isolated from pwCF will be further analyzed by WGS.…”

Comparative survival of environmental and clinical Mycobacterium abscessus isolates in a variety of diverse host cells

“…Isolates 1–3 and 5–8 were identified as MABS and Isolate 4 was identified as Arthrobacter sp . as determined by Sanger sequencing of a partial region in the rpoB gene as we have published (Honda et al, 2016 ; Virdi et al, 2021 ). The MABS type strain ATCC 19977 was included as a positive control (Isolate 7).…”

“…Within our studies of nontuberculous mycobacteria (NTM) in the US geographic hot spot of Hawai'i, we have demonstrated recovery of viable MABS from a variety of built and natural environments (Honda et al, 2016;Virdi et al, 2021). From this collection, a panel of environmental and clinical MABS was studied to fill in the current knowledge gaps of understudied environmental MABS isolates.…”

Sex, ancestry, senescence, and aging (SAnSA) are stark drivers of nontuberculous mycobacterial pulmonary disease

“…Susceptibility also extends to individuals with prior lung infections, bronchiectasis, and genetic diseases such as cystic fibrosis, alpha-1 antitrypsin deficiency, and primary ciliary dyskinesia [8] . These vulnerabilities and other exposures have been previously reviewed in the literature [9] , [10] .…”