Susceptibility of Elizabethkingia spp. to commonly tested and novel antibiotics and concordance between broth microdilution and automated testing methods

Abstract

Objectives We aimed to determine susceptibilities of Elizabethkingia spp. to 25 commonly tested and 8 novel antibiotics, and to compare the performance of different susceptibility testing methods. Methods Clinical isolates of Elizabethkingia spp., Chryseobacterium spp. and Flavobacterium spp. collected during 2002–18 (n = 210) in a nationwide surveillance programme in Taiwan were speciated by 16S rRNA sequencing. MICs were determined by broth microdilution. The broth microdilution results of 18 common antibiotics were compared with those obtained by the VITEK 2 automated system. Results Among the Elizabethkingia spp. identified (n = 108), Elizabethkingia anophelis was the most prevalent (n = 90), followed by Elizabethkingia meningoseptica (n = 7) and Elizabethkingia miricola cluster [E. miricola (n = 6), Elizabethkingia bruuniana (n = 3) and Elizabethkingia ursingii (n = 2)]. Most isolates were recovered from respiratory or blood specimens from hospitalized, elderly patients. PFGE showed two major and several minor E. anophelis clones. All isolates were resistant to nearly all the tested β-lactams. Doxycycline, minocycline and trimethoprim/sulfamethoxazole inhibited >90% of Elizabethkingia spp. Rifampin inhibited E. meningoseptica (100%) and E. anophelis (81.1%). Fluoroquinolones and tigecycline were active against E. meningoseptica and E. miricola cluster isolates. Novel antibiotics, including imipenem/relebactam, meropenem/vaborbactam, ceftazidime/avibactam, cefepime/zidebactam, delafloxacin, eravacycline and omadacycline were ineffective but lascufloxacin inhibited half of Elizabethkingia spp. The very major discrepancy rates of VITEK 2 were >1.5% for ciprofloxacin, moxifloxacin and vancomycin. Major discrepancy rates were >3% for amikacin, tigecycline, piperacillin/tazobactam and trimethoprim/sulfamethoxazole. Conclusions MDR, absence of standard interpretation criteria and poor intermethod concordance necessitate working guidelines to facilitate future research of emerging Elizabethkingia spp.

The Evolutionary Trend and Genomic Features of an Emerging Lineage of Elizabethkingia anophelis Strains in Taiwan

“…4 ). We also investigated 90 isolates from multiple hospitals in the TSAR program between 2002 and 2018 ( 18 ). The earliest isolate belonging to the dominant lineage was identified in 2008 from a hospital in northern Taiwan.…”

“…A study in Shanghai, China evaluated antimicrobial susceptibility of 52 Elizabethkingia isolates (including 35 E. anophelis , 14 E. meningoseptica , and 2 E. miricola ) and minocycline was more active than doxycycline and tigecycline (≤ 4 μg/ml, 100% versus 96.2% and 78.8%, respectively) ( 24 ). Another study in Taiwan also demonstrated that 100% (90/90), 96.7% (87/90), and 52.2% (47/90) of E. anophelis isolates were susceptible to minocycline, doxycycline and tigecycline, respectively ( 18 ). Though no current breakpoint value is available, the clinical use of tetracycline, especially for minocycline and doxycycline, to treat E. anophelis infections warrants more investigations.…”

“…First, molecular epidemiologic studies could be extended to investigate the local and global trends of E. anophelis infections related to the specific lineage with time. Second, while some antimicrobial agents such as vancomycin or rifampin were reported to be active in vitro against some Elizabethkingia species ( 18 , 31 ), we did not assess the impact of antimicrobial therapy chosen based on the available antimicrobial susceptibility on the outcome of E. anophelis infections.…”

“…The E. anophelis isolates collected in the Taiwan Surveillance of Antimicrobial Resistance (TSAR) program from 2002 (TSARIII) to 2018 (TSARIX) were included in trend analysis. The TSAR program is a biannual nationwide bacteria repository program in Taiwan since 1998 ( 18 ).…”

Elizabethkingia anophelis: An Important Emerging Cause of Neonatal Sepsis and Meningitis in China

“…1 Compared with E. meningoseptica , E. anophelis was significantly more susceptible to piperacillin/tazobactam, minocycline and levofloxacin, 5 but less susceptible to ciprofloxacin, moxifloxacin and tigecycline. 20 In our study, the two E. anophelis isolates were all sensitive to piperacillin/tazobactam. Due to limited laboratory conditions, we did not conduct vancomycin susceptibility tests.…”