Bacterial biofilms and quorum sensing

The Ecology, Biology and Pathogenesis of Acinetobacter spp.: An Overview

Acinetobacter are a major concern because of their rapid development of resistance to a wide range of antimicrobials, and rapid profundity in transformation, surviving desiccation and persisting in the environment for a very long time. The organisms are associated with bacteraemia, pulmonary infections, meningitis, diarrhea and notorious nosocomial infections with mortality rates of 20 to 60%. Transmission is via person-to-person contact, water and food contamination, and contaminated hospital equipment. The increasing virulence and rapid development of multidrug resistance by these organisms highlights the need to search for alternatives for chemotherapy. A poor understanding of the organisms and dearth of information about their occurrence especially in developing countries informed the need for this review paper.

Comparative Biology of IncQ and IncQ-Like Plasmids

Plasmids belonging to Escherichia coli incompatibility group Q are relatively small (approximately 5 to 15 kb) and able to replicate in a remarkably broad range of bacterial hosts. These include gram-positive bacteria such as Brevibacterium and Mycobacterium and gram-negative bacteria such as Agrobacterium, Desulfovibrio, and cyanobacteria. These plasmids are mobilized by several self-transmissible plasmids into an even more diverse range of organisms including yeasts, plants, and animal cells. IncQ plasmids are thus highly promiscuous. Recently, several IncQ-like plasmids have been isolated from bacteria found in environments as diverse as piggery manure and highly acidic commercial mineral biooxidation plants. These IncQ-like plasmids belong to different incompatibility groups but have similar broad-host-range replicons and mobilization properties to the IncQ plasmids. This review covers the ecology, classification, and evolution of IncQ and IncQ-like plasmids.

The biology and potential biotechnological applications of Bacillus safensis