Objective: To describe Dyella species associated with cystic fibrosis (CF). Methods: Phenotypic identification by VITEK-2; mass spectrometry; 16S rDNA sequencing; minimal inhibitory concentration by Etest and categorisation as susceptible (S) or resistant (R) according to EUCAST interpretative criteria for Pseudomonas. Results: An oxidase-positive Gram-negative rod was isolated on Burkholderia cepacia selective agar in May 2009. Initially the bacterium was identified by VITEK-2 as Elizabethkingia meningoseptica, however subsequent 16S rRNA gene sequencing revealed it belonged to genus Dyella. Only one single human infection with Dyella (bacteremia in a hemodialysis patient) has been described previously. Dyella species was cultured from this patient in 5 of 11 sputum samples during 2010, and from 8 of 10 specimens in 2011, rendering the patient chronically infected when applying the "Leeds criteria" often used for Pseudomonas aeruginosa infection. An unusual antibiotic susceptibility pattern was observed: piperacillin-tazobactam, 3 mg/L (S); meropenem, >32 mg/L (R); fosfomycin, 256 mg/L (R); ciprofloxacin, 3 mg/L (R); moxifloxacin, 0.25 mg/L (no breakpoint); tobramycin, 3 mg/L (S); colistin, >256 mg/L (R). A unique MALDI-TOF mass spectrum was displayed, and the strain is easily recognised by mass spectrometry after the generation of reference spectra. The patient experienced a steep decline in FEV1 (approx. 4%/year) for several years prior to and after colonisation with Dyella. Conclusion: Bacteria of genus Dyella can colonise the CF lung and pose a diagnostic challenge for the clinical microbiology laboratory. The clinical significance of the colonisation is unknown.
Duus, L. M., Wang, M., Schiøtz, O., & Nørskov-Lauritsen, N. (2012). 128 Dyella species – a new opportunistic pathogen or an innocent bystander in cystic fibrosis? Journal of Cystic Fibrosis, 11, S89. https://doi.org/10.1016/s1569-1993(12)60298-7