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In Vitro Antifungal Susceptibilities of Uncommon Basidiomycetous Yeasts. Carolina Serena, 2004.The in vitro activities of eight antifungal drugs against 50 isolates of basidiomycetous yeasts were determined by a microdilution method . In general fluconazole and micafungin were inactive . Terbinafine was active only against Sporobolomyces salmonicolor . The activities of the other antifungals were variable and depended on the species tested . The new triazoles showed the lowest MICs, but amphotericin B and itraconazole were the only drugs active against Cryptococcus albidus . The Superoxide Dismutase Gene sodM Is Unique to Staphylococcus aureus: Absence of sodM in Coagulase-Negative Staphylococci. Michelle Wright Valderas, 2002.Superoxide dismutase (SOD) profiles of clinical isolates of Staphylococcus aureus and coagulase-negative staphylococci (CoNS) were determined by using whole-cell lysates and activity gels . All S . aureus clinical isolates exhibited three closely migrating bands of activity as previously determined for laboratory strains of S . aureus: SodM, SodA, and a hybrid composed of SodM and SodA (M . W . Valderas and M . E . Hart, J . Bacteriol . 183:3399-3407, 2001) . In contrast, the CoNS produced only one SOD activity, which migrated similarly to SodA of S . aureus . Southern analysis of eight CoNS species identified only a single sod gene in each case . A full-length sod gene was cloned from Staphylococcus epidermidis and determined to be more similar to sodA than to sodM of S . aureus . Therefore, this gene was designated sodA . The deduced amino acid sequence of the S . epidermidis sodA was 92 and 76% identical to that of the SodA and SodM proteins of S . aureus, respectively . The S . epidermidis sodA gene expressed from a plasmid complemented a sodA mutation in S . aureus, and the protein formed a hybrid with SodM of S . aureus . Both hybrid SOD forms as well as the SodM and SodA proteins of S . aureus and the S . epidermidis SodA protein exist as dimers . These data indicate that sodM is found only in S . aureus and not in the CoNS, suggesting an important divergence in the evolution of this genus and a unique role for SodM in S . aureus . Metagenomic Analyses of an Uncultured Viral Community from Human Feces. Mya Breitbart, 2003.Here we present the first metagenomic analyses of an uncultured viral community from human feces, using partial shotgun sequencing . Most of the sequences were unrelated to anything previously reported . The recognizable viruses were mostly siphophages, and the community contained an estimated 1,200 viral genotypes . IS6110-Mediated Deletion Polymorphism in the Direct Repeat Region of Clinical Isolates of Mycobacterium tuberculosis. S. L. Sampson, 2003.This study investigates the phenomenon of IS6110-mediated deletion polymorphism in the direct repeat (DR) region of the genome of Mycobacterium tuberculosis . Clinical isolates and their putative predecessors were compared using a combination of DR region restriction fragment length polymorphism, IS6110 DNA fingerprinting, spoligotyping, and DNA sequencing, which allowed the mapping of chromosome structure and deletion junctions . The data suggest that adjacently situated IS6110 elements mediate genome deletion . However, in contrast to previous reports, deletions appear to be mediated by inversely oriented IS6110 elements . This suggests that these events may occur via mechanisms other than RecA-mediated homologous recombination . The results underscore the important role of IS6110-associated deletion hypervariability in driving M . tuberculosis genome evolution . Disinfection of Water Containing Natural Organic Matter by Using Ozone-Initiated Radical Reactions. Min Cho, 2003.Ozone is widely used to disinfect drinking water and wastewater due to its strong biocidal oxidizing properties . Recently, it was reported that hydroxyl radicals (·OH), resulting from ozone decomposition, play a significant role in microbial inactivation when Bacillus subtilis endospores were used as the test microorganisms in pH controlled distilled water . However, it is not yet known how natural organic matter (NOM), which is ubiquitous in sources of drinking water, affects this process of disinfection by ozone-initiated radical reactions . Two types of water matrix were considered for this study . One is water containing humic acid, which is commercially available . The other is water from the Han River . This study reported that hydroxyl radicals, initiated by the ozone chain reaction, were significantly effective at B . subtilis endospore inactivation in water containing NOM, as well as in pH-controlled distilled water . The type of NOM and the pH have a considerable effect on the percentage of disinfection by hydroxyl radicals, which ranged from 20 to 50% . In addition, the theoretical  T value of hydroxyl radicals for 2-log B . subtilis removal was estimated to be about 2.4 x 104 times smaller than that of ozone, assuming that there is no synergistic activity between ozone and hydroxyl radicals .
Evidence of Chemolithoautotrophy in the Bacterial Community Associated with Alvinella pompejana, a Hydrothermal Vent Polychaete. Barbara J. Campbell, 2003.The deep-sea polychaete Alvinella pompejana colonizes tubes on the sides of black smoker chimneys along the East Pacific Rise . A diverse, yet phylogenetically constrained episymbiotic community is obligately associated with its dorsal surface . The morphologically and phylogenetically distinct dominant episymbionts have not yet been cultured, and there are no clearly defined roles for these bacteria in this symbiosis . A large insert fosmid library was screened for the presence of the two dominant phylotypes . Two fosmids, 35.2 and 38 kb, containing phylotype-specific 16S ribosmal DNA sequences were fully sequenced . Each fosmid had a gene encoding ATP citrate lyase, a key enzyme in the reverse tricarboxylic acid (rTCA) cycle, a CO2 fixation pathway . A selection of episymbiont communities from various geographic locations and vent sites were screened for the presence, diversity, and expression (via reverse transcription-PCR) of the ATP citrate lyase gene . Our results indicate that the ATP citrate lyase gene is not only a consistent presence in these episymbiont communities but is also expressed . Phylogenetically distinct forms of ATP citrate lyase were also found associated with and expressed by bacteria extracted from the tubes of A . pompejana . Utilizing PCR with degenerate primers based on a second key enzyme in the rTCA cycle, 2-oxoglutarate:acceptor oxidoreductase, we also demonstrated the persistent presence and expression of this gene in the episymbiont community . Our results suggest that members of both the episymbiont and the surrounding free-living communities display a chemolithoautotrophic form of growth and therefore contribute fixed carbon to other organisms in the vent community .
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