AUTHOR=Akorli Esinam Abla , Ubiaru Prince Chigozirim , Pradhan Sabyasachi , Akorli Jewelna , Ranford-Cartwright Lisa 

TITLE=Bio-products from Serratia marcescens isolated from Ghanaian Anopheles gambiae reduce Plasmodium falciparum burden in vector mosquitoes

JOURNAL=Frontiers in Tropical Diseases

VOLUME=3

YEAR=2022

URL=https://www.frontiersin.org/journals/tropical-diseases/articles/10.3389/fitd.2022.979615

DOI=10.3389/fitd.2022.979615

ISSN=2673-7515

ABSTRACT=<p>Novel ideas for control of mosquito-borne disease include the use of bacterial symbionts to reduce transmission. Bacteria belonging to the family Enterobacteriaceae isolated from mosquito midgut have shown promise in limiting <italic>Plasmodium</italic> intensity in the <italic>Anopheles</italic> vector. However, the mechanism of interaction between bacteria and parasite remains unclear. This study aimed at screening bio-products of two bacteria candidates for their anti-Plasmodial effects on mosquito stages of <italic>P. falciparum. Enterobacter cloacae</italic> and <italic>Serratia marcescens</italic> were isolated from field-caught <italic>Anopheles gambiae</italic> s.l. Spent media from liquid cultures of these bacteria were filtered, lyophilized and dissolved in sterile phosphate buffered saline (PBS). The re-dissolved bacterial products were added to gametocytaemic blood meals and fed to <italic>An. gambiae</italic> mosquitoes <italic>via</italic> membrane feeders. Control groups were fed on infected blood with or without lyophilized LB medium. The effect of the products on the infection prevalence and intensity of <italic>P. falciparum</italic> in mosquitoes was assessed by dissecting mosquito midguts and counting oocysts 10-11 days post-infection. <italic>S. marcescens</italic> bio-products elicited significant reduction in the number of mosquitoes infected (<italic>P</italic>=4.02 x10<sup>-5</sup>) with <italic>P. falciparum</italic> and the oocyst intensity (<italic>P</italic>&lt;2 x 10<sup>-16</sup>) than <italic>E. cloacae</italic> products (<italic>P</italic>&gt;0.05 for both prevalence and intensity) compared to the control (lyophilized LB medium). These data support the use of bioproducts released by <italic>S. marcescens</italic> for malaria control based on transmission blocking in the vector.</p>