Suspected contaminated Genome sequence in public archives

Genome deposits in public archives may be less reliable, even though the genomes that are submitted to public archives are scrutinized for erroneous sequences, mistakes can slip through. These mistakes include instances of cross-species contamination. According to a study by scientists at Johns Hopkins University, a public database, GenBank, contains draft assemblies of animal and plant genomes that have been contaminated by bacterial and viral sequences. In particular, the scientists learned that a draft assembly of domestic cow, Bos taurus, contained 173 small contigs that appeared to derive from microbial contaminants. Surprised by this finding, the scientists delved deeper and discovered the presence of cow and sheep DNA in the supposedly finished genome of a pathogenic bacterium, Neisseria gonorrhoeae.