Structural Analysis of Biofilm Formation by Rapidly and Slowly Growing Nontuberculous Mycobacteria

Williams, Margaret M.; Yakrus, Mitchell A.; Arduino, Matthew J.; Cooksey, Robert C.; Crane, Christina B.; Banerjee, Shailen N.; Hilborn, Elizabeth D.; Donlan, Rodney M.

doi:10.1128/aem.00166-09

Cited by 83 publications

(65 citation statements)

References 36 publications

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“…The reasons for the enrichment of mycobacteria are not clear. Mycobacteria readily form biofilms and, because of their generally waxy quality, may be particularly resistant to shear forces generated in shower operation (28)(29)(30)(31)(32)(33)(34)(35)(36). Furthermore, many species of biofilm-forming mycobacteria are chlorineresistant, and thus potentially can be enriched by chlorine disinfection protocols used by many municipalities (28,29,34,37,38).…”

Section: Discussionmentioning

confidence: 99%

Opportunistic pathogens enriched in showerhead biofilms

Feazel

Baumgartner²,

Peterson³

et al. 2009

Proc. Natl. Acad. Sci. U.S.A.

497

364

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The environments we humans encounter daily are sources of exposure to diverse microbial communities, some of potential concern to human health. In this study, we used culture-independent technology to investigate the microbial composition of biofilms inside showerheads as ecological assemblages in the human indoor environment. Showers are an important interface for human interaction with microbes through inhalation of aerosols, and showerhead waters have been implicated in disease. Although opportunistic pathogens commonly are cultured from shower facilities, there is little knowledge of either their prevalence or the nature of other microorganisms that may be delivered during shower usage. To determine the composition of showerhead biofilms and waters, we analyzed rRNA gene sequences from 45 showerhead sites around the United States. We find that variable and complex, but specific, microbial assemblages occur inside showerheads. Particularly striking was the finding that sequences representative of non-tuberculous mycobacteria (NTM) and other opportunistic human pathogens are enriched to high levels in many showerhead biofilms, >100-fold above background water contents. We conclude that showerheads may present a significant potential exposure to aerosolized microbes, including documented opportunistic pathogens. The health risk associated with showerhead microbiota needs investigation in persons with compromised immune or pulmonary systems.bioaerosols ͉ Mycobacterium avium complex ͉ Non-tuberculous mycobacteria ͉ public health ͉ rRNA metagenomics

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Section: Discussionmentioning

confidence: 99%

Opportunistic pathogens enriched in showerhead biofilms

Feazel

Baumgartner²,

Peterson³

et al. 2009

Proc. Natl. Acad. Sci. U.S.A.

497

364

View full text Add to dashboard Cite

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“…A key ability of NTM, becoming regarded as very important, is the formation of biofilms in the environment and hypothetically in vivo (13). Moreover, biofilm development and formation can consist of several distinct types of structures.…”

Section: Ecology and Epidemiologymentioning

confidence: 99%

Host Response to Nontuberculous Mycobacterial Infections of Current Clinical Importance

Orme

Ordway

2014

Infect Immun

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The nontuberculous mycobacteria are a large group of acid-fast bacteria that are very widely distributed in the environment. While Mycobacterium avium was once regarded as innocuous, its high frequency as a cause of disseminated disease in HIV-positive individuals illustrated its potential as a pathogen. Much more recently, there is growing evidence that the incidence of M. avium and related nontuberculous species is increasing in immunocompetent individuals. The same has been observed for M. abscessus infections, which are very difficult to treat; accordingly, this review focuses primarily on these two important pathogens. Like the host response to M. tuberculosis infections, the host response to these infections is of the TH1 type but there are some subtle and as-yet-unexplained differences.A lthough nontuberculous mycobacteria have long been recognized, there is far less information regarding their pathogenicity than that of their more famous relatives Mycobacterium tuberculosis and Mycobacterium leprae. It is becoming increasingly clear, however, that the incidence of certain members of the nontuberculous mycobacterial family may be increasing, an observation not related simply to better recognition, typing, and diagnosis. Of this family, the host response to M. avium is perhaps the best understood, but even here there are interesting differences in the expression of immunity that have yet to be explained. NOMENCLATUREOne cannot begin to address this issue without considering the current nomenclature, a morass in itself. We are using here the term "nontuberculous mycobacteria" (NTM) but could easily use "atypical mycobacteria," "environmental mycobacteria," the subset "rapidly growing mycobacteria" (RGM), "mycobacteria other than M. tuberculosis," or even the "quasi-too-complex" term that can be applied to M. avium and M. abscessus. NTM is perhaps the most widely used, but one has to realize that "tuberculous" refers to "not tuberculosis" not "no tubercles." ECOLOGY AND EPIDEMIOLOGYNTM were suspected as potential causes of human infections in the sanatorium era, but it was not until the 1950s that direct evidence became available. Even then, NTM were initially regarded as simple saprophytes of limited, if any, virulence occurring only in people with other predisposing lung conditions (as discussed further below). This opinion, of course, changed dramatically when M. avium complex (MAC) species emerged as major opportunistic infections in patients with HIV and more recently with observations of increases in infections with other NTM such as M. abscessus in elderly patients.Because of extensive research, including seminal work by Falkinham, we now know that NTM are widely distributed in the environment and can cause opportunistic infections in multiple mammals, fish, and birds (particularly poultry) (1). In fact, it seems that NTM can grow essentially anywhere (2) and thrive where competing microbes are destroyed, such as in chlorinated water (3). In untreated water, NTM can even parasitize amoebae (4, 5). Eve...

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“…These bacteria can adhere to biomedical materials (catheters, prosthesis, filters or membranes of inhalation systems) forming a biofilm that may complicate the pharmacological treatment of such infections (Williams et al, 2009). …”

Section: General Aspectsmentioning

confidence: 99%