River Sediments Downstream of Villages in a Karstic Watershed Exhibited Increased Numbers and Higher Diversity of Nontuberculous Mycobacteria.

The impact of residential villages on the nontuberculous mycobacteria (NTM) in streams flowing through them has not been studied in detail. Water and sediments of streams are highly susceptible to anthropogenic inputs such as surface water flows. This study investigated the impact of seven residential villages in a karst watershed on the prevalence and species spectrum of NTM in water and sediments.

Nitrate and nitrite reductase activities of .

Background: In spite of the fact that the standard test for nitrate reductase activity is negative for Mycobacterium avium, it can grow in a defined minimal medium with either nitrate (NO) or nitrite (NO) as sole nitrogen sources.

Methods: NO-and NO-reductase activities were measured in soluble and membrane fractions of aerobically grown cells of M. avium and those grown aerobically and shifted to anaerobiosis.