Rare Elizabethkingia anophelis meningitis case in a Danish male

Abstract

Introduction: Elizabethkingia anophelis is a Gram-negative, aerobic, non-motile rod belonging to the family Flavobacteriaceae. Over the last 5 years, it has emerged as an opportunistic human pathogen involved in neonatal meningitis and sepsis, as well as nosocomial outbreaks. It has been isolated from the midgut of the Anopheles gambiae mosquito, but there is no evidence for a role of the mosquito in human infections, and very little is known regarding the routes of transmission to humans. Recent studies, primarily from South-East Asia, suggest that E. anophelis, and not Elizabethkingia meningoseptica, is the predominant human pathogen of this genus. However, identification to the species level has been difficult due to the limitations of the current MALDI-TOF MS (matrix-associated laser desorption ionization-time of flight MS) systems for correct species identification.

Case presentation: Here, we present a rare case of E. anophelis meningitis in a Danish male, who had a travel exposure to Malaysia 7 weeks before hospitalization. A multidrug-resistant Elizabethkingia species was isolated from blood and cerebrospinal fluid, and genomic sequencing was used to characterize the phylogenetic position of the isolate, which was determined as associated with previously described sublineage 11. The patient was successfully treated with intravenous moxifloxacin and rifampicin for 2 weeks with no major sequelae, but we did not find the source of transmission.

Conclusion: All clinical microbiologists should be aware of the present limitations of the MALDI-TOF MS systems for correct species identification, and therefore we recommend the use of genome sequencing for the correct identification at the species and sublineage level.

Keywords: Elizabethkingia; Elizabethkingia anopheles; antibiotic treatment; meningitis; mosquito; moxifloxacin; rifampicin; sepsis; whole-genome sequencing.

Fig. 1.

Dendrogram of the E. anophelis strains available on the Institut Pasteur server generated by use of BIGSdb software (http://bigsdb.pasteur.fr/elizabethkingia/). The tree was obtained using the UPGMA algorithm based on cgMLST allelic profiles. The scale represents the proportion of loci with distinct alleles among the 1546 gene loci. Our isolate (AAUH 98722) was shown to belong to sublineage 11, which was defined with strain CIP 60-59.