Medical Microbiology & Diagnosis

Isolation and Identification of Bacterial Fauna from the Midgut of Anopheles gambiae complex in Malaria Endemic Areas of Northern Nigeria

Abstract

Habibu U. Abdu

Malaria parasites transmission in Nigeria is primarily due to the genus Anopheles. This study was carried out with the aim to isolate and identify bacteria from midgut of Anopheles species. A total of 200 Anopheles mosquito larvae, 100 each from Agricultural field sites (strain A) and residential sites (strain R) were collected and reared to adults. Susceptibility bio-assay performed on the adults Anopheles. Anopheles mosquitoes were anesthetized by chloroform and dissected. 70% of ethanol was used for surface sterilization of mosquitoes and laboratory equipment, followed by rinsing Anopheles mosquitoes four times with 1X PBS. Each dissected midgut from the Anopheles mosquitoes was transferred in 1X PBS and squashed, labeled and incubated in the water bath and enriched in tryptic soya broth for 24 h at 35 ± 2 °C.  The culture dependent approach using different mediums was used to investigate the bacterial biodiversity. The microbiota in the two pools of Anopheles was diverse with strain R showing a greater gut bacterial diversity than strain A, with both strains dominated by Gram-negative bacteria. The more resistant strain (Strain A) showed lower bacterial diversity. This finding can be used as a baseline for studying the relationship between microbiota and mosquitoes, and for the development of a new malaria biological control. The gut bacterial populations of Anopheles gambiae could be a crucial determinant of their life histories, and the expression of insecticide resistance.