scholarly journals The presence of opportunistic pathogens, Legionella spp., L. pneumophila and Mycobacterium avium complex, in South Australian reuse water distribution pipelines

2014 ◽  
Vol 13 (2) ◽  
pp. 553-561 ◽  
Author(s):  
H. Whiley ◽  
A. Keegan ◽  
H. Fallowfield ◽  
R. Bentham
Keyword(s):  
Mycobacterium Avium ◽  
Water Reuse ◽  
Water Distribution ◽  
Mycobacterium Avium Complex ◽  
Human Pathogens ◽  
Opportunistic Pathogens ◽  
Potential Health ◽  
Reuse Water ◽  
Chlorine Residual ◽  
Polymerase Chain

Water reuse has become increasingly important for sustainable water management. Currently, its application is primarily constrained by the potential health risks. Presently there is limited knowledge regarding the presence and fate of opportunistic pathogens along reuse water distribution pipelines. In this study opportunistic human pathogens Legionella spp., L. pneumophila and Mycobacterium avium complex were detected using real-time polymerase chain reaction along two South Australian reuse water distribution pipelines at maximum concentrations of 105, 103 and 105 copies/mL, respectively. During the summer period of sampling the concentration of all three organisms significantly increased (P < 0.05) along the pipeline, suggesting multiplication and hence viability. No seasonality in the decrease in chlorine residual along the pipelines was observed. This suggests that the combination of reduced chlorine residual and increased water temperature promoted the presence of these opportunistic pathogens.

Nontuberculous Mycobacteria

2021 ◽  
Vol 42 (04) ◽  
pp. 567-586
Author(s):  
Shera Tan ◽  
Shannon Kasperbauer
Keyword(s):  
Risk Factor ◽  
Pulmonary Disease ◽  
Mycobacterium Avium ◽  
Mycobacterium Avium Complex ◽  
Nontuberculous Mycobacteria ◽  
Mycobacterium Abscessus ◽  
Pulmonary Infections ◽  
Human Pathogens ◽  
Common Manifestation

AbstractNontuberculous mycobacteria (NTM) are ubiquitous in the environment and 193 species of NTM have been discovered thus far. NTM species vary in virulence from benign environmental organisms to difficult-to-treat human pathogens. Pulmonary infections remain the most common manifestation of NTM disease in humans and bronchiectasis continues to be a major risk factor for NTM pulmonary disease (NTM PD). This article will provide a useful introduction and framework for clinicians involved in the management of bronchiectasis and NTM. It includes an overview of the epidemiology, pathogenesis, diagnosis, and management of NTM PD. We will address the challenges faced in the diagnosis of NTM PD and the importance of subspeciation in guiding treatment and follow-up, especially in Mycobacterium abscessus infections. The treatment of both Mycobacterium avium complex and M. abscessus, the two most common NTM species known to cause disease, will be discussed in detail. Elements of the recent ATS/ERS/ESCMID/IDSA NTM guidelines published in 2020 will also be reviewed.

scholarly journals Mycobacterium avium Complex (MAC) in Water Distribution Systems and Household Plumbing in the United States

Water ◽  
2020 ◽  
Vol 12 (12) ◽  
pp. 3338
Author(s):  
Joseph O. Falkinham
Keyword(s):  
Drinking Water ◽  
Mycobacterium Avium ◽  
Distribution Systems ◽  
Water Distribution ◽  
Mycobacterium Avium Complex ◽  
Water Distribution Systems ◽  
Treatment Plant ◽  
The United States ◽  
Fecal Coliforms ◽  
Plate Count

Members of the Mycobacterium avium complex (MAC) are waterborne, opportunistic pathogens whose characteristics make urban water distribution systems and household plumbing ideal habitats for their survival, persistence and growth. Rather than contaminants, MAC are colonists of drinking water systems. MAC are normal inhabitants of natural soils and water, and enter drinking water treatment systems through surface sources. A proportion of MAC survive transmission through the treatment plant, and regrow in the distribution system and household plumbing. Once within household plumbing, MAC adhere to surfaces and form biofilms, thus preventing their washout. The thermal tolerance of MAC leads to growth in water heating systems. Stagnation does not reduce MAC numbers, as MAC can grow at low oxygen levels. MAC present challenges to current water monitoring approaches as their numbers do not correlate with E. coli, fecal coliforms or heterotrophic plate count bacteria.

scholarly journals Mycobacterium avium complex (MAC) genomics and transmission in a London hospital

2022 ◽  
Author(s):  
Andries J van Tonder ◽  
Huw C Ellis ◽  
Colin P Churchward ◽  
Kartik Kumar ◽  
Newara Ramadan ◽  
...  
Keyword(s):  
Mycobacterium Avium ◽  
Mycobacterium Avium Complex ◽  
Mycobacterium Abscessus ◽  
Control Measures ◽  
Opportunistic Pathogens ◽  
Future Studies ◽  
Asymptomatic Carriage ◽  
Royal Brompton Hospital ◽  
Population Structures ◽  
Global Population

Non-tuberculous mycobacteria (NTM) are ubiquitous environmental microorganisms and opportunistic pathogens in individuals with pre-existing lung conditions such as cystic fibrosis (CF) and non-CF bronchiectasis (BX). Whilst recent studies of Mycobacterium abscessus have identified transmission within single CF centres as well as nationally and globally, transmission of other NTM species is less well studied. We sequenced 1000 Mycobacterium avium complex (MAC) isolates from CF and non-CF patients at the Royal Brompton Hospital (RBH), London. Epidemiological links were identified from patient records. Previously published genomes were used to characterise global population structures. Analysis of the three most predominant MAC species identified putative transmission clusters that contained patients with CF, BX and other lung conditions, although few epidemiological links could be identified. For M. avium, lineages were largely limited to single countries, whilst for M. chimaera, global transmission clusters previously associated with heater cooler units (HCUs) were found. However, the origin of the major HCU-associated outbreak was a lineage already circulating in patients with pre-existing lung conditions. CF and non-CF patients share transmission chains even in the presence of CF patient-focussed hospital control measures, although the lack of epidemiological links suggests that most transmission is indirect and may be due to environmental foci or else asymptomatic carriage in the wider population. The major HCU-associated M. chimaera lineage being derived from an already circulating lineage, suggests that HCUs are not the sole vector nor the ultimate source of this lineage. Future studies should include sampling of environmental reservoirs and potential asymptomatic carriers.

scholarly journals Discrimination of members of the Mycobacterium avium complex by polymerase chain reaction

1999 ◽  
Vol 30 (2) ◽  
pp. 144-148
Author(s):  
Marcelo Palma Sircili ◽  
Eliana Roxo ◽  
Sylvia Cardoso Leão
Keyword(s):  
Mycobacterium Avium ◽  
Mycobacterium Avium Complex ◽  
Insertion Sequence ◽  
Protein Gene ◽  
Single Copy ◽  
Polymorphism Analysis ◽  
Chain Reaction ◽  
Biochemical Identification ◽  
Restriction Polymorphism ◽  
Polymerase Chain

Mycobacterium avium complex (MAC) species cannot be discriminated by the usual methods of biochemical identification of mycobacteria. This study showed that amplification by PCR of DT1 and DT6, two single copy sequences identified in the genome of M. avium serotype 2, the insertion sequence IS1245, found to be consistently present in M. avium strains and the heat-shock protein gene hsp65, followed by restriction polymorphism analysis, are rapid and accurate tests for the differentiation of the species M. avium, M. intracellulare, and M. scrofulaceum.

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