Targeted Development of Registries of Biological Parts

BACKGROUND: The design and construction of novel biological systems by combining basic building blocks represents a dominant paradigm in synthetic biology. Creating and maintaining a database of these building blocks is a way to streamline the fabrication of complex constructs. The Registry of Standard Biological Parts (Registry) is the most advanced implementation of this idea. METHODS/PRINCIPAL FINDINGS: By analyzing inclusion relationships between the sequences of the Registry entries, we build a network that can be related to the Registry abstraction hierarchy. The distribution of entry reuse and complexity was extracted from this network. The collection of clones associated with the database entries was also analyzed. The plasmid inserts were amplified and sequenced. The sequences of 162 inserts could be confirmed experimentally but unexpected discrepancies have also been identified. CONCLUSIONS/SIGNIFICANCE: Organizational guidelines are proposed to help design and manage this new type of scientific resources. In particular, it appears necessary to compare the cost of ensuring the integrity of database entries and associated biological samples with their value to the users. The initial strategy that permits including any combination of parts irrespective of its potential value leads to an exponential and economically unsustainable growth that may be detrimental to the quality and long-term value of the resource to its users

Drug resistance of Mycobacterium tuberculosis strains isolated from HIV-infected Italian patients: preliminary report from a multicentric study

A multicentric prospective study started in March '93 to describe both initial and acquired resistance of Mycobacterium Tuberculosis in Italian HIV+ patients (Pyrazinamide (pts.) to first line drugs: Rifampin (R), Isoniazid (I), Pyrazinamide (P), Ethambutol (E), Streptomycin (S). All tuberculosis (TB) cases diagnosed in HIV+ patients (pts.) were included, along with clinical-anamnestical data. Drug-susceptibility tests were performed centrally. Preliminary results indicate an overall low frequency of TB resistance to first line drugs: R=2%, P=4%, S=9%, I/E=none. However, a relevant nosocomial outbreak of multiple drug resistant (DR) TB was detected. This finding, along with some previous Italian reports of DR-TB clusters, may herald a further spread of DR-TB. Surveillance, therefore, is mandatory in Italy from now on