In Silico Identification of Three Types of Integrative and Conjugative Elements in Elizabethkingia anophelis Strains Isolated from around the World

Abstract

Elizabethkingia anophelis is an opportunistic human pathogen, and the genetic diversity between strains from around the world becomes apparent as more genomes are sequenced. Genome comparison identified three types of putative ICEs in 31 of 36 strains. The diversity of ICEs suggests that they had different origins. One of the ICEs was discovered previously from a large E. anophelis outbreak in Wisconsin in the United States; this ICE has integrated into the mutY gene of the outbreak strain, creating a mutator phenotype. Similar to ICEs found in many bacterial species, ICEs in E. anophelis carry various cargo genes that enable recipients to resist antibiotics and adapt to various ecological niches. The adaptive immune CRISPR-Cas system is present in nine of 36 strains. An ICE-derived spacer was found in the CRISPR locus in a strain that has no ICE, suggesting a past encounter and effective defense against ICE.