Three cases of Mycobacterium avium complex-related lung disorders were associated with two poorly maintained spa pools by genotypic investigations. Inadequate disinfection of the two spas had reduced the load of environmental bacteria to less than 1 CFU/ml but allowed levels of M. avium complex of 4.3 ؋ 10 4 and 4.5 ؋ 10 3 CFU/ml. Persistence of the disease-associated genotype was demonstrated in one spa pool for over 5 months until repeated treatments with greater than 10 mg of chlorine per liter for 1-h intervals eliminated M. avium complex from the spa pool. A fourth case of Mycobacterium avium complex-related lung disease was associated epidemiologically but not genotypically with another spa pool that had had no maintenance undertaken. This spa pool contained low numbers of mycobacteria by smear and was culture positive for M. avium complex, and the nonmycobacterial organism count was 5.2 ؋ 10 6 CFU/ml. Public awareness about the proper maintenance of private (residential) spa pools must be promoted by health departments in partnership with spa pool retailers.Mycobacterium species are ubiquitous in the environment and are found worldwide (7,9,14,21,30). They have a predilection for a variety of natural waters, including lakes, rivers, and streams, and have also been detected in water supply systems (1,6,7,13,14,15,30). In a study of eight water supply distribution systems across the United States, the average number of M. avium in biofilms was 0.3 CFU per cm 2 and the number of M. intracellulare was 600 CFU per cm 2 for all surfaces (13). Mycobacteria not only survive but may persist and increase in number, and waters that have traversed such systems yield mycobacteria. Human beings are regularly exposed to these waters, which represent a potential source for infection.End uses of supplied water are myriad but include industry (machine coolant fluids), hospitals, commercial buildings, residential garden watering, residential drinking and cooking, hot water systems, baths and showers, swimming pools, spa pools or hot tubs, ice machines, aquariums, and miscellaneous purposes such as foot bath whirlpools (1,6,7,12,13,14,26,29,31). Recirculating hot water systems in buildings, spas, and hot tubs have yielded high numbers of M. avium. Indeed, hot water systems may have higher numbers of M. avium than the source water (10). Swimming pools have also yielded M. avium (12), and long-term exposure to aerosols has caused granulomatous pneumonitis in lifeguards (25).A number of reports have demonstrated an association of M. avium complex (MAC) in spa pools with lung disorders in humans (5,11,16,17,18,20). However, most did not study the relationship between clinical and environmental strains except for two studies that used restriction fragment length polymorphism and multilocus enzyme electrophoresis to demonstrate a genotypic link between MAC isolates from the patient and the spa pool (17,20). The present study attempted to define the source, burden, and persistence of MAC in spa pools associated with four cases of l...

Introduction of molecular biology-based technology into an Australian mycobacterial reference laboratory has resulted in the identification of three isolates of Mycobacterium interjectum in the past 12 months. Conventional phenotypic methods failed to identify the species of these isolates, and high-performance liquid chromatography found that only one of the three isolates had a mycolic acid pattern similar to that of the type strain. In contrast, all three isolates were rapidly identified as M. interjectum by 16S rRNA gene sequence analysis. Two isolates were recovered from the lymph nodes of children with cervical lymphadenitis, confirming the pathogenicity of this organism. However, the third isolate was obtained from the sputum of an elderly male with chronic lung disease without evidence of clinical or radiological progression, suggesting that isolation of M. interjectum should not imply disease. With the increasing use of molecular biology-based technology in mycobacterial laboratories, M. interjectum may be recognized more frequently as a pathogen or commensal organism.

Fire is an important ecological process that shapes vegetation structure and habitat for faunal assemblages globally. Prescribed burns are increasingly being used in conservation and management to restore fire regimes in fire-suppressed vegetation communities. Small threatened macropods require structurally complex habitat that allows them to evade detection by predators. Given that fire can alter vegetation structure, it can be viewed as a strong ecological force in shifting the dynamics between predator and prey species. Previous studies in temperate Australia have shown that prescribed burns in the presence of European Red Fox (Vulpes vulpes) and feral Cat (Felis catus) can have negative impacts on small macropods and medium-sized mammals. Post-fire response of threatened small macropods and their predators has not been experimentally examined in subtropical Australia despite this region providing refugia for the Long-nosed Potoroo (Potorous tridactylus) and Red-legged Pademelon (Thylogale stigmatica). We conducted a before-after-control-impact fire experiment at two paired sites after low-moderate intensity burns typical of cool season prescribed burns. We used camera trapping to investigate changes in activity of threatened small macropods and their predators. We also recorded vegetation change. Despite large reductions in ground and shrub cover, activity of small macropods and the Dingo (Canis dingo) did not change in response to fires. Therefore, the threat of dingo predation appears to have remained unchanged following the fires. Although feral cats and foxes were present, they showed negligible activity across our sites. Our study suggests that small-scale patchy ecological burns may not lead to increased predation of small macropods in our landscape. We attribute this to sufficient post-fire refugia and very low densities of foxes.

A slow-growing mycobacterium was isolated from a cervical lymph node of an adolescent male. This isolate produced small, smooth, scotochromogenic colonies after 6 weeks of incubation at 25 degrees C and 30 degrees C (but not at 37 degrees C or 43 degrees C). The results of 16S-rRNA gene sequencing and high-performance liquid chromatography suggest that this isolate belongs to a hitherto unrecognised pathogenic species.

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