Microbiological Characterization and Clinical Facets of Elizabethkingia Bloodstream Infections in a Tertiary Care Hospital of Eastern India.

PURPOSE: Elizabethkingia is an emerging non-fermenting Gram-negative bacillus (NFGNB) causing bloodstream infections (BSI) associated with high mortality. It demonstrates a unique antimicrobial profile in showing susceptibility to antimicrobials effective against Gram-positive bacteria. This study was undertaken to determine the overall frequency of Elizabethkingia BSI, associated risk factors, microbiological susceptibility, and clonal relationship of Elizabethkingia isolates using Enterobacterial Repetitive Intergenic Consensus Polymerase Chain Reaction (ERIC-PCR).

PATIENTS AND METHODS: Elizabethkingia isolates obtained from the blood culture of admitted patients (August 2020-December 2021) were identified by the VITEK 2 system and subjected to an antimicrobial susceptibility test by standard procedures. Demographics, co-morbidities, risk factors for survival, and outcome were summarized and analyzed by Chi-square test, Kaplan-Meier curve, and Cox regression. Clonal relatedness between Elizabethkingia isolates was analyzed using ERIC‑PCR fingerprinting with the "PAST: Paleontological statistics software package".

RESULTS: Of 13,747 blood samples received during the study period, 13.59% were culture positive, and 14.60% were NFGNBs. The frequency of Elizabethkingia spp. among all NFGNBs in BSI was 29.30%, and the overall prevalence in BSI was 4.21%. In patients with Elizabethkingia BSI, Foley's catheter was present in 81.25% of the cases. 100% susceptibility was observed to linezolid, followed by vancomycin (98.75%) and chloramphenicol (89.5%). The 30-day mortality rate in the patients of Elizabethkingia BSI was 26.25%. The Presence of COVID-19, pneumonia, diabetes mellitus (DM), mechanical ventilation (MV), and prior antibiotics were significantly different (p<0.05) between the survival and death groups. ERIC-PCR profile dendrogram of Elizabethkingia isolates showed ten major clusters indicating high genetic diversity.

CONCLUSION: Elizabethkingia was responsible for one-third of NFGNB BSI in a single-center study, with approximately 26% of 30-day all-cause mortality. Most isolates were susceptible to linezolid, vancomycin, and chloramphenicol. COVID-19 was the most significant risk factor associated with mortality. ERIC-PCR of Elizabethkingia isolates exhibited high genetic diversity.