M. lentiflavum in Drinking Water Supplies | CDC EID

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Volume 17, Number 3–March 2011
Research
Mycobacterium lentiflavum in Drinking Water Supplies, Australia
Henry M. Marshall, Robyn Carter, Matthew J. Torbey, Sharri Minion, Carla Tolson, Hanna E. Sidjabat, Flavia Huygens, Megan Hargreaves, and Rachel M. Thomson

Author affiliations: The Prince Charles Hospital, Brisbane, Queensland, Australia (H.M. Marshall); The Royal Brisbane Hospital, Brisbane (R. Carter, M.J. Torbey, S. Minion, C. Tolson); University of Queensland Centre for Clinical Research, Brisbane (H.E. Sidjabat); Queensland University of Technology, Brisbane (F. Huygens, M. Hargreaves); and Queensland Tuberculosis Control Centre, Brisbane (R.M. Thomson)

Suggested citation for this article

Abstract
Mycobacterium lentiflavum, a slow-growing nontuberculous mycobacterium, is a rare cause of human disease. It has been isolated from environmental samples worldwide. To assess the clinical significance of M. lentiflavum isolates reported to the Queensland Tuberculosis Control Centre, Australia, during 2001–2008, we explored the genotypic similarity and geographic relationship between isolates from humans and potable water in the Brisbane metropolitan area. A total of 47 isolates from 36 patients were reported; 4 patients had clinically significant disease. M. lentiflavum was cultured from 13 of 206 drinking water sites. These sites overlapped geographically with home addresses of the patients who had clinically significant disease. Automated repetitive sequence–based PCR genotyping showed a dominant environmental clone closely related to clinical strains. This finding suggests potable water as a possible source of M. lentiflavum infection in humans.

Mycobacterium lentiflavum organisms are nontuberculous mycobacteria (NTM) first identified in 1996 (1). M. lentiflavum is slow growing at 22°C–37°C and has yellow pigmentation, negative tests for Tween 80 hydrolysis, nicotinic acid, nitrate reductase and urease, distinct fatty and mycolic acid patterns, and unique 16S rRNA and 65-kDa heat-shock protein gene sequences. It shares phenotypic features with M. avium but is more closely related to M. simiae and M. genavense. Because of similarities to M. avium complex (MAC), differentiation can be difficult without molecular identification, hence, misclassification in the past is possible (2).

As with other NTM, M. lentiflavum has been isolated from soil and water samples around the world. However, links between environmental sources and human disease have not yet been demonstrated.

In Queensland, Australia (population 4.28 million), NTM disease is notifiable. A central reference laboratory performs speciation of all positive isolates. In 2008, ≈900 isolates of NTM were reported.

Strain variation within mycobacterial species is well known. Although epidemiologic studies provide useful information, molecular strain typing can be invaluable, especially if a single clone can be linked to an outbreak source. Pulsed-field gel electrophoresis (PFGE) has been considered the standard for mycobacterial strain typing but is time- and labor- intensive and requires expensive dedicated equipment. Also, DNA degradation can occur during electrophoresis, generating uninterpretable banding patterns (3). Repetitive sequence–based PCR (rep-PCR) has been used to differentiate mycobacterial strains associated with disease outbreaks in mesotherapy clinics (M. abscessus and M. chelonae) (4) and in patients after surgery (M. fortuitum) (5). An automated rep-PCR system (DiversiLab; bioMérieux, Melbourne, Victoria, Australia) showed high concordance with PFGE results (6) in identifying mycobacterial strain clusters and was faster than PFGE.

We had 2 goals for this study. First, we aimed to describe the clinical significance and outcomes of M. lentiflavum infection in Queensland. Second, we intended to explore the genotypic and geographic relationship between patient isolates and potable water isolates in the Brisbane area.

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M. lentiflavum in Drinking Water Supplies | CDC EID


Suggested Citation for this Article
Marshall HM, Carter R, Torbey MJ, Minion S, Tolson C, Sidjabat HE, et al. Mycobacterium lentiflavum in drinking water supplies, Australia. Emerg Infect Dis [serial on the Internet]. 2011 Mar [date cited].
http://www.cdc.gov/EID/content/17/3/395.htm


DOI: 10.3201/eid1703.090948


Comments to the Authors
Please use the form below to submit correspondence to the authors or contact them at the following address:

Henry M. Marshall, The Prince Charles Hospital–Thoracic Medicine, Rode Rd, Chermside, Brisbane, QLD 4032, Australia; email: henry_marshall@health.qld.gov.au