Complete genome sequence and lifestyle of black-pigmented <it>Corynebacterium aurimucosum </it>ATCC 700975 (formerly <it>C. nigricans </it>CN-1) isolated from a vaginal swab of a woman with spontaneous abortion

• Main Authors: Gartemann Karl-Heinz, Blom Jochen, Bekel Thomas, Arnold Walter, Viehoever Prisca, Tilker Alexandra, Szczepanowski Rafael, Schneiker-Bekel Susanne, Schneider Jessica, Götker Susanne, Trost Eva, Linke Burkhard, Goesmann Alexander, Pühler Alfred, Shukla Sanjay K, Tauch Andreas
• Format: Article
• Language: English
• Published: BMC 2010-02-01
• Series: BMC Genomics
• Online Access: http://www.biomedcentral.com/1471-2164/11/91

<p>Abstract</p> <p>Background</p> <p><it>Corynebacterium aurimucosum </it>is a slightly yellowish, non-lipophilic, facultative anaerobic member of the genus <it>Corynebacterium </it>and predominantly isolated from human clinical specimens. Unusual black-pigmented variants of <it>C. aurimucosum </it>(originally named as <it>C. nigricans</it>) continue to be recovered from the female urogenital tract and they are associated with complications during pregnancy. <it>C. aurimucosum </it>ATCC 700975 (<it>C. nigricans </it>CN-1) was originally isolated from a vaginal swab of a 34-year-old woman who experienced a spontaneous abortion during month six of pregnancy. For a better understanding of the physiology and lifestyle of this potential urogenital pathogen, the complete genome sequence of <it>C. aurimucosum </it>ATCC 700975 was determined.</p> <p>Results</p> <p>Sequencing and assembly of the <it>C. aurimucosum </it>ATCC 700975 genome yielded a circular chromosome of 2,790,189 bp in size and the 29,037-bp plasmid pET44827. Specific gene sets associated with the central metabolism of <it>C. aurimucosum </it>apparently provide enhanced metabolic flexibility and adaptability in aerobic, anaerobic and low-pH environments, including gene clusters for the uptake and degradation of aromatic amines, L-histidine and L-tartrate as well as a gene region for the formation of selenocysteine and its incorporation into formate dehydrogenase. Plasmid pET44827 codes for a non-ribosomal peptide synthetase that plays the pivotal role in the synthesis of the characteristic black pigment of <it>C. aurimucosum </it>ATCC 700975.</p> <p>Conclusions</p> <p>The data obtained by the genome project suggest that <it>C. aurimucosum </it>could be both a resident of the human gut and possibly a pathogen in the female genital tract causing complications during pregnancy. Since hitherto all black-pigmented <it>C. aurimucosum </it>strains have been recovered from female genital source, biosynthesis of the pigment is apparently required for colonization by protecting the bacterial cells against the high hydrogen peroxide concentration in the vaginal environment. The location of the corresponding genes on plasmid pET44827 explains why black-pigmented (formerly <it>C. nigricans</it>) and non-pigmented <it>C. aurimucosum </it>strains were isolated from clinical specimens.</p>