Журнал бактериологии и паразитологии

Абстрактный

Fitness dynamics and costs of genetically modified Entrobacter cloacae expressing a defensin for paratransgenesis in Phlebotomus papatasi

Rangin Abassi, Maryam Akhlaghi, Mohammed Ali Oshaghi, Amir Ahmad Akhavan, Mohammad Reza Yaghoubi-Ershadi, Runak Bakhtiari and Fatemeh Mokhtarami

Background: Enterobacter cloacae subsp. dissolvens is a known commensal of the gut microbiota of Phlebotomus papatasi , the major vector of zoonotic cutaneous leishmaniasis, and has been nominated for paratransgenesis in sandflies. In this study, we assessed the dynamics and fitness costs of an engineered E. cloacae for its potential to serve as a Trojan horse for P. papatasi .

Methods: An engineered E. cloacae strain was transformed with a constitutively active red fluorescent protein plus defensin (EC-DR) expression plasmid and fed to mosquito colonies via larval food. Wild-type bacteria (EC-WT) and undamaged food were used as controls. Fitness characteristics as well as the dynamics of EC-DR at different stages of mosquito larval development were tested by plating homogenized samples and counting colonies expressing the fluorescent signal on Tet-BHI agar medium.

Results: Enterobacter cloacae DR producing red fluorescent protein could be isolated from the larval gut after 36 days when the bacteria were added once to the larval pots. EC-DR, when applied multiple times, had no negative effect on the emergence time of instar larvae, pupae and adults, but slightly increased the mortality rate of P. papatasi larvae . The experiment also confirmed the absence or weak transstadial transmission of E. cloacae DR in P. papatasi . It has minimal effect on the feeding behavior and survival of P. papatasi .

Conclusion: The results of this study showed that E. cloacae DR is suitable for paratransgenesis of P. papatasi only at the adult stage, since it is not transmitted transstadially.