Antimicrobial Resistance, Virulence Factors, and Genotypes of Enterococcus faecalis and Enterococcus faecium Clinical Isolates in Northern Japan: Identification of optrA in ST480 E. faecalis

and are the major pathogens causing community- and healthcare-associated infections, with an ability to acquire resistance to multiple antimicrobials. The present study was conducted to determine the prevalence of virulence factors, drug resistance and its genetic determinants, and clonal lineages of and clinical isolates in northern Japan. A total of 480 (426 and 54 ) isolates collected over a four-month period were analyzed. Three virulence factors promoting bacterial colonization ( , , and ) were more prevalent among (46-59%) than , while a similar prevalence of enterococcal surface protein gene ( ) was found in these species. Between and , an evident difference was noted for resistance to erythromycin, gentamicin, and levofloxacin and its responsible resistance determinants. Oxazolidinone resistance gene and phenicol exporter gene were identified in an isolate of belonging to ST480 and revealed to be located on a cluster similar to those of isolates reported in other Asian countries. The isolates analyzed were differentiated into 12 STs, among which ST179 and ST16 of clonal complex (CC) 16 were the major lineage. Nearly all the isolates were assigned into CC17, which consisted of 10 different sequence types (STs), including a dominant ST17 containing multidrug resistant isolates and ST78 with isolates harboring the hyaluronidase gene ( ). The present study revealed the genetic profiles of and clinical isolates, with the first identification of in ST480 in Japan.