An autonomous plasmid as an inovirus phage satellite.

Bacterial viruses (phages) are potent agents of lateral gene transfer and thus are important drivers of evolution. A group of mobile genetic elements, referred to as phage satellites, exploits phages to disseminate their own genetic material. Here, we isolated a novel member of the family Inoviridae, Shewanella phage Dolos, along with an autonomously replicating plasmid, pDolos. Dolos causes a chronic infection in its host Shewanella oneidensis by phage production with only minor effects on the host cell proliferation. When present, plasmid pDolos hijacks Dolos functions to be predominantly packaged into phage virions and released into the environment and, thus, acts as a phage satellite. pDolos can disseminate further genetic material encoding, e.g., resistances or fluorophores to host cells sensitive to Dolos infection. Given the rather simple requirements of a plasmid for takeover of an inovirus and the wide distribution of phages of this group, we speculate that similar phage-satellite systems are common among bacteria.IMPORTANCEPhage satellites are mobile genetic elements, which hijack phages to be transferred to other host cells. The vast majority of these phage satellites integrate within the host's chromosome, and they all carry remaining phage genes. Here, we identified a novel phage satellite, pDolos, which uses an inovirus for dissemination. pDolos (i) remains as an autonomously replicating plasmid within its host, (ii) does not carry recognizable phage genes, and (iii) is smaller than any other phage satellites identified so far. Thus, pDolos is the first member of a new class of phage satellites, which resemble natural versions of phagemids.

Safety of a universal, virus-inactivated and prion-depleted, pharmaceutical-quality plasma: a randomized, double-blind, clinical trial in healthy volunteers.

BACKGROUND: Universal plasma is intended to be transfused irrespective of the blood group. We compared the safety and tolerability of a novel, universal blood group-independent plasma with an ABO-matched plasma. STUDY DESIGN AND METHODS: In this randomized, double-blind, active-controlled, crossover, Phase I trial, 30 healthy adult volunteers (blood group A, B, or AB) were randomly assigned to transfusion of 1200 mL of Uniplas LG and 1200 mL of Octaplas LG (both Octapharma AG) or vice versa. In both periods, plasmapheresis (PPh, 600 mL) preceded the infusion. Blood samples were drawn before and after PPh and 15 minutes, 2 hours, 24 hours, and 7 days after end of plasma transfusion, to assess safety and efficacy. The primary safety outcome was change in hemoglobin (Hb) concentration; secondary safety outcomes were direct antiglobulin test (DAT), complement activation, free Hb, haptoglobin, and indirect bilirubin. Efficacy was assessed by evaluation of coagulation variables. RESULTS: Variations of Hb concentration were similar between treatments and within normal range; 90% confidence interval was within predefined limits of equivalence. No subject exhibited a positive DAT. All other secondary variables which could reflect hemolytic transfusion reactions (HTRs) fell within normal range; this suggests that no HTRs occurred. Most adverse events were of mild intensity; two subjects experienced dyspnea, leading to the withdrawal from the study of one subject. CONCLUSION: Universal plasma was equivalent to ABO-matched plasma with respect to safety and tolerability. Eliminating the risk of ABO incompatibility, this universal plasma represents an advance over blood group-specific plasma.