Comparative genomic analysis of malaria mosquito vector-associated novel pathogen Elizabethkingia anophelis

Acquisition of Elizabethkingia infections in intensive care units (ICUs) has risen in the past decade. Treatment of Elizabethkingia infections is challenging due to the lack of effective therapeutic regimens, leading to a high mortality rate. Elizabethkingia infections have long been attributed to Elizabethkingia meningoseptica. Recently, we used whole-genome sequencing to reveal that E. anophelis is the pathogenic agent for an Elizabethkingia outbreak at two ICUs. We performed comparative genomic analysis of seven hospital-isolated E. anophelis strains with five available Elizabethkingia spp. genomes deposited in the National Center for Biotechnology Information Database. A pan-genomic approach was applied to identify the core- and pan-genome for the Elizabethkingia genus. We showed that unlike the hospital-isolated pathogen E. meningoseptica ATCC 12535 strain, the hospital-isolated E. anophelis strains have genome content and organization similar to the E. anophelis Ag1 and R26 strains isolated from the midgut microbiota of the malaria mosquito vector Anopheles gambiae. Both the core- and accessory genomes of Elizabethkingia spp. possess genes conferring antibiotic resistance and virulence. Our study highlights that E. anophelis is an emerging bacterial pathogen for hospital environments.