Bacteria endosymbionts: a source of innovation in biotechnology for the control of vector-borne diseases

di Maurizio Calvitti - ENEA, Technical Unit for Sustainable Development and Agro-Industrial Innovation

Currently available strategies to fight mosquito vector-borne diseases are insufficient, and new approaches need to be developed according to modern economical and ecological sustainability parameters. In this review we discuss the recent advances  in the exploitation of endosymbiotic bacteria as biological tool for mosquito vector control, in particular for Aedes species, to which  the asian tiger mosquito, widely spread also in Italy, belongs.The alfa-proteobacteria Wolbachia are among the most common intracellular bacteria and have recently emerged as important drivers of arthropod biology. Wolbachia commonly act as reproductive parasites in arthropod inducing cytoplasmic incompatibility (CI) a type of conditional sterility between hosts harbouring incompatible infection types. Two main strategies of using this bacterium for mosquito vector control are presented: (1) the first, treated more extensively, since it directly involves ENEA research activity, exploits cytoplasmic incompatibility as natural source of sterility in place of ionizing radiation for the sterile insect technique (renamed Incompatible Insect Technique), (2) the second, uses the reproductive  advantages, conferred by the incompatibility cytoplasmic to infected females,  to promote the invasion and ultimately the replacement of natural populations, with individuals carrying advantageous phenotypic traits like low pathogen competence.

New scientific evidence regarding the interaction between the symbiotic bacteria and its effects on the hosts, in particular the interference with their ability to transmit pathogens, is further increasing the interest of biologists and entomologists to the study of these symbiotic associations arthropod-bacterium