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Isolation of Glucocardiolipins from Geobacillus stearothermophilus NRS 2004/3a. Christina Schäffer, 2002.Glucose-substituted cardiolipins account for about 4 mol% of total phospholipid extracted from exponentially grown cells of Geobacillus stearothermophilus NRS 2004/3a . Individual glucocardiolipin species exhibited differences in fatty acid substitution, with iso-C15:0 and anteiso-C17:0 prevailing . The compounds were purified to homogeneity by a novel protocol and precharacterized by matrix-assisted laser desorption ionization time-of-flight mass spectrometry . FarR Regulates the farAB-Encoded Efflux Pump of Neisseria gonorrhoeae via an MtrR Regulatory Mechanism. E.-H. Lee, 2003.The farAB operon of Neisseria gonorrhoeae encodes an efflux pump which mediates gonococcal resistance to antibacterial fatty acids . It was previously observed that expression of the farAB operon was positively regulated by MtrR, which is a repressor of the mtrCDE-encoded efflux pump system (E.-H . Lee and W. M . Shafer, Mol . Microbiol . 33:839-845, 1999) . This regulation was believed to be indirect since MtrR did not bind to the farAB promoter . In this study, computer analysis of the gonococcal genome sequence database, lacZ reporter fusions, and gel mobility shift assays were used to elucidate the regulatory mechanism by which expression of the farAB operon is modulated by MtrR in gonococci . We identified a regulatory protein belonging to the MarR family of transcriptional repressors and found that it negatively controls expression of farAB by directly binding to the farAB promoter . We designated this regulator FarR to signify its role in regulating the farAB operon . We found that MtrR binds to the farR promoter, thereby repressing farR expression . Hence, MtrR regulates farAB in a positive fashion by modulating farR expression . This MtrR regulatory cascade seems to play an important role in adjusting levels of the FarAB and MtrCDE efflux pumps to prevent their excess expression in gonococci . PCR Detection and Analysis of the Free-Living Amoeba Naegleria in Hot Springs in Yellowstone and Grand Teton National Parks. Kathy B. Sheehan, 2003.Free-living thermotolerant amoebae pose a significant health risk to people who soak and swim in habitats suitable for their growth, such as hot springs . In this survey of 23 different hot springs in Yellowstone and Grand Teton National Parks, we used PCR with primer sets specific for Naegleria to detect three sequence types that represent species not previously described, as well as a fourth sequence type identified as the pathogen Naegleria fowleri .
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