The arsenic resistance listeria genomic island LGI2 exhibits sequence and integration site diversity and propensity for three Listeria monocytogenes clones with enhanced virulence.

The arsenic resistance listeria genomic island LGI2 exhibits sequence and integration site diversity and propensity for three Listeria monocytogenes clones with enhanced virulence. Appl Environ Microbiol. 2017 Aug 25;: Authors: Lee S, Ward TJ, Jima DD, Parsons C, Kathariou S Abstract In the foodborne pathogen Listeria monocytogenes, arsenic resistance is primarily encountered in serotype 4b clones considered to have enhanced virulence, and is associated with an arsenic resistance gene cluster within a 35 kb chromosomal region, Listeria genomic island 2 (LGI2). LGI2 was first identified in strain Scott A and includes genes putatively involved in arsenic and cadmium resistance, DNA integration, conjugation and pathogenicity. However, genomic localization and sequence content of LGI2 remain poorly characterized. Here we investigated 85 arsenic-resistant L. monocytogenes strains, mostly of serotype 4b. All but one of the 70 serotype 4b strains belonged to clonal complexes CC1, CC2 and CC4, three major clones associated with enhanced virulence. PCR analysis suggested that 53 strains (62.4%) harbored an island highly similar to LGI2 of Scott A, frequently (42/53) in the same location as Scott A (LMOf2365_2257 homolog). Random-primed PCR and whole genome sequencing revealed seven novel insertion sites, mostly internal to chromosomal coding sequences, among strains harboring LGI2 outside the LMOf2365_2257 homolog. Interestingly, many CC1 str...
Source: Applied and Environmental Microbiology - Category: Microbiology Authors: Tags: Appl Environ Microbiol Source Type: research