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J Bacteriol. 2012 October; 194(19): 5481.
PMCID: PMC3457201

Draft Genome Sequences of Enterobacter sp. Isolate Ag1 from the Midgut of the Malaria Mosquito Anopheles gambiae


An isolate of Enterobacter sp. was obtained from the microbial community within the gut of the Anopheles gambiae mosquito, a major malaria vector in Africa. This genome was sequenced and annotated. The genome sequences will facilitate subsequent efforts to characterize the mosquito gut microbiome.


The mosquito gut ecosystem harbors a complex microbiota with a dynamic taxonomic composition at different stages of the insect's life. Taxa from the family Enterobacteriaceae were selectively enriched by blood meals in adult mosquitoes (8). Enterobacter sp. is one of the abundant gut inhabitants and has been identified in various mosquitoes, such as Anopheles gambiae, Anopheles stephensi, Anopheles funestus, Anopheles albimanus, Aedes triseriatus, Aedes aegypti, Culex pipiens, and Psorophora columbiae (3, 58). Furthermore, an isolate of Enterobacter sp. from wild mosquitoes has demonstrated the ability to interfere with the development of Plasmodium falciparum, the causative agent of malaria, in the mosquito midgut (2). We have sequenced the genome of an isolate of Enterobacter sp. that was obtained from the midgut of Anopheles gambiae. Here we report the draft genome sequences.

The cultivatable bacteria from the midgut of mosquito Anopheles gambiae were grown on a BBL PC agar plate. Several colonies were identified as Enterobacter sp. based on the 16S rRNA gene sequences. The genome of one isolate, the Enterobacter sp. strain Ag1, was sequenced using Illumina paired-end technology at BGI America. The sequence reads (~650 Mbp) were de novo assembled with the DNAStar SeqMan NGen assembler (v.10.0), which generated 64 contigs totaling 4.75 Mbp. The genome was annotated using NCBI Prokaryotic Genome Automatic Annotation Pipeline (, which predicted 4,433 protein-coding features and 83 RNA genes. Among them, 3,614 protein features were assigned to 530 subsystems by the SEED subsystem at the RAST server (1). One thousand nine hundred seventy-one (54.5%) protein features belong to the following subsystems: carbohydrates, amino acids and derivatives, cofactors, vitamins, prosthetic groups, pigments, cell wall and capsule, and protein metabolism. In the blood-fed gut, blood digestion imposes acute oxidative stress (4). Enterobacter is among the bacteria that expand in the blood-fed gut (8). The presence of 179 stress response genes demonstrates the genetic capability of Enterobacter to live in the stressful blood-fed gut. This is consistent with the speculation that the gut-resident microbes may provide additional genetic capacity to cope with the blood meal-associated oxidative stress in the gut ecosystem (4, 8).

The draft genome sequences, in combination with other genomes of mosquito-associated bacteria, such as Elizabethkingia sp. strain Ag1 (accession no. AHHG01000000) and Pseudomonas sp. strain Ag1 (accession no. AKVH01000000), will serve as references for functional characterization of the mosquito gut microbiome.

Nucleotide sequence accession numbers.

This Whole Genome Shotgun project has been deposited at DDBJ/EMBL/GenBank under the accession no. AKXM00000000. The version described in this paper is the first version, AKXM01000000.


This work was supported by the NIH grant 1SC2GM092789-01A1. C.A. was an undergraduate research scholar supported by the NMSU Howard Hughes Medical Institute (HHMI) research scholars program.


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