Elizabethkingia Infections in Humans: From Genomics to Clinics

Abstract

The genus Elizabethkingia has recently emerged as a cause of life-threatening infections in humans, particularly in immunocompromised patients. Several new species in the genus Elizabethkingia have been proposed in the last decade. Numerous studies have indicated that Elizabethkingia anophelis, rather than Elizabethkingia meningoseptica, is the most prevalent pathogen in this genus. Matrix-assisted laser desorption/ionization–time of flight mass spectrometry systems with an extended spectrum database could reliably identify E. anophelis and E. meningoseptica, but they are unable to distinguish the remaining species. Precise species identification relies on molecular techniques, such as housekeeping gene sequencing and whole-genome sequencing. These microorganisms are usually susceptible to minocycline but resistant to most β-lactams, β-lactam/β-lactam inhibitors, carbapenems, and aminoglycosides. They often exhibit variable susceptibility to piperacillin, piperacillin-tazobactam, fluoroquinolones, and trimethoprim-sulfamethoxazole. Accordingly, treatment should be guided by antimicrobial susceptibility testing. Target gene mutations are markedly associated with fluoroquinolone resistance. Knowledge on the genomic characteristics provides valuable insights into in these emerging pathogens.

Risk Factors, Antimicrobial Susceptibility Patterns and Carbapenem Resistance Mechanisms of Elizabethkingia anophelis Clinical Isolates From a University Tertiary Hospital in Southwest China

“…In previous reports, the case fatality rate of patients with E. anophelis infection ranged from 24-60% in different countries [4][5][6][7][8][9][10][11][12][13][14]. In line with this, our study showed that the in-hospital mortality rate of patients with an E. anophelis infection was 51.3%.…”

“…Thereafter, the prevalence of E. anophelis infections has been rampant; it is the primary species of Elizabethkingia genus infections that have recently occurred in Singapore [3], Hong Kong [4], the United States [5,6,7,8], South Korea [9] and Taiwan [10]. E. anophelis is an important opportunistic pathogen associated with various invasive infections in adults with underlying diseases and infants (premature and neonates) [11,12]. Several outbreaks have occurred in Singapore and in the Midwestern United States of Wisconsin, Illinois, and Michigan, where the fatality rate of patients with E. anophelis infections ranged from 30-60% [5,6,7,8].…”

<p>Molecular Characteristics and Antimicrobial Susceptibility Profiles of <em>Elizabethkingia</em> Clinical Isolates in Shanghai, China</p>

“…The reports varied on the susceptibility of Elizabethkingia isolates against fluoroquinolones. 32 Favored in vitro activity of fluoroquinolones was observed in this study, and the susceptibility rate for levofloxacin was higher than that for ciprofloxacin. By contrast, fluoroquinolones exhibited poor activity against E. anophelis and E. meningoseptica while all E. miricola isolates were susceptible to levofloxacin and moxifloxacin in a hospital in South Korea.…”

“…18,20 In this study, we also found that the identification for Emi007 was ambiguous with 16S rRNA gene sequencing, which could be partly explained by the existence of multiple copies with different sequences and the hypervariable regions of 16S rRNA. 32 It has been pointed out that the rpoB gene is a single copy gene and has a higher resolution of phylogenetic evolution than the 16S rRNA gene; thus, it could accurately distinguish Elizabethkingia strains at the species level. 7,32 PFGE profiles showed finer resolution of clonal relationships, indicating that Emi007 was genetically more related to Emi099 than Emi088 with a similarity of 81.1%, thereby supporting its identity as E. miricola.…”

An Overview of the Treatment of Less Common Non–Lactose‐Fermenting Gram‐Negative Bacteria

“…It is often characterized by its "dumbbell" shape. 36 Like Chryseobacterium, Elizabethkingia species may appear thin, long, and slightly curved on gram stain. The bacterium was discovered in 1959 by Elizabeth O.…”