Conjugative Plasmid pPPUT-Tik1-1 from a Permafrost Strain and Its Present-Day Counterparts Inhabiting Environments and Clinics.

A novel group of conjugative plasmids of is characterized. The prototype plasmid pPPUT-Tik1-1 (153,663 bp), isolated from a permafrost strain of Tik1, carries a defective mercury transposon, Tn, and a streptomycin resistance transposon, Tn Ten plasmids and 34 contigs with backbone regions closely related to pPPUT-Tik1-1 have been found in GenBank. Two of these plasmids from clinical strains of and are almost identical to the ancient plasmid.

Predictive model for preoperative risk calculation of cerebrospinal fluid leak after resection of midline craniofacial mass lesions.

Background: Complex anterior skull base defects produced by resection of mass lesions vary in size and configuration and may be extensive. We analyzed the largest single-center series of midline craniofacial lesions extending intra- and extracranially. The study aims at the development of a predictive model for preoperative measurement of the risk of the postoperative cerebrospinal fluid (CSF) leak based on patients' characteristics and surgical plans.

Plasmids as Key Players in Adaptation.

This review briefly summarizes the data on the mechanisms of development of the adaptability of to various living conditions in the environment and in the clinic. A comparative analysis of the genomes of free-living and clinical strains of , as well as the genomes of and has been carried out. It has been shown that plasmids, both large and small, play a key role in the formation of the adaptability of to their living conditions.

Ubiquitous Conjugative Mega-Plasmids of Species and Their Role in Horizontal Transfer of Multi-Drug Resistance.

Conjugative mega-plasmids play a special role in adaptation since they carry a huge number of accessory genes, often allowing the host to develop in new niches. In addition, due to conjugation they are able to effectively spread themselves and participate in the transfer of small mobilizable plasmids. In this work, we present a detailed characterization of a recently discovered family of multiple-drug resistance mega-plasmids of species, termed group III-4a.