Comparison of Clinical Manifestations, Antimicrobial Susceptibility Patterns, and Mutations of Fluoroquinolone Target Genes between Elizabethkingia meningoseptica and Elizabethkingia anophelis Isolated in Taiwan

Abstract

<i>Elizabethkingia</i> <i>meningoseptica</i> and Elizabethkingia <i>anophelis</i> are two major pathogens in the genus <i>Elizabethkingia</i>. Studies have revealed that Elizabethkingia <i>anophelis</i> is frequently misidentified as <i>E. meningoseptica</i>. Therefore, our aim was to explore the clinical and molecular differences between these two species. The database of a clinical microbiology laboratory in a university-affiliated hospital of Taiwan was searched to identify patients with <i>Elizabethkingia</i> infections between January 2005 and June 2018. Species were reidentified using 16S ribosomal RNA gene sequencing. Twenty <i>E. meningoseptica</i> and 72 <i>E. anophelis</i> samples were collected from consecutive patients. <i>E. meningoseptica</i> was significantly more frequently isolated from the cerebrospinal fluid than was <i>E. anophelis</i>. The most susceptible antibiotic for all <i>Elizabethkingia</i> isolates was minocycline (91.3%), followed by levofloxacin (52.2%), tigecycline (23.9%), and piperacillin tazobactam (23.9%). Compared with <i>E. anophelis</i>, <i>E. meningoseptica</i> was significantly less susceptible to piperacillin tazobactam, minocycline, and levofloxacin. Regarding nonsynonymous substitutions in the quinolone-resistance determining regions of DNA gyrase, six sites were recognized in <i>E. meningoseptica</i> and one site was recognized in <i>E. anophelis</i>. <i>E. meningoseptica</i> had a significantly higher rate of fluoroquinolone target gene mutations than did <i>E. anophelis</i>. Because of less susceptibility to multiple antibiotics than <i>E. anophelis</i>, empirical antimicrobial therapy of <i>E. meningoseptica</i> should be more rigorous.