Ralstonia pickettii bacteremia: An emerging infection in a Tertiary care hospital setting

Abstract

Background: Ralstonia species are Gram-negative bacilli that have increasingly been recognized as emerging nosocomial pathogens particularly in immunocompromised hosts. Ralstonia pickettii is the most clinically important pathogen from the Ralstonia genus. Nosocomial outbreaks of Ralstonia pickettii infections brought about by use of contaminated medical solutions including saline, sterile water as well as disinfectants have been reported. There have been case reports of invasive infections with variable presentations. Here we describe three cases of Ralstonia pickettii bacteremia during a period of one year in a tertiary care hospital in Karachi, Pakistan. Case description: Case1: A 76 year old male known case of Type 2 Diabetes Mellitus, Hypertension and Amyotrophic lateral sclerosis presented with complaints of burning micturition, hematuria and fever. Patient had history of multiple hospital admissions in the recent past. His blood culture was found to be positive for Ralstonia pickettii. CT KUB was suggestive of pyelonephritis. Patient improved on intravenous Meropenem. Case 2: A 47 year old gentleman with no prior co-morbids was admitted with gunshot injury to the neck resulting in complete cervical cord resection and mild hydrocephalus with intraventricular haemorrhage. Patient had a prolonged ICU stay which was complicated by ventilator associated pneumonia with Acinetobacter and central line associated bloodstream infection with Ralstonia pickettii. He was treated with Meropenem and colistin but continued to deteriorate and expired. Case 3: 46 year old lady, known case of end stage renal disease, admitted with prosthetic valve endocarditis, had prolonged hospital stay complicated by central line associated blood stream infection with Ralstonia pickettii, improved on Meropenem but later died due to fungemia. Discussion: Ralstonia pickettii is an emerging gram-negative opportunistic pathogen. Ralstonia pickettii has been rarely known to cause severe invasive infections, including pneumonia, endocarditis, osteomyelitis, meningitis, and septic arthritis. It is a waterborne organism of low virulence, with a propensity to cause severe infections in the immunocompromised. Among our cases, two of the patients had chronic debilitating illnesses, which could have predisposed them to infection with this organism. Conclusion: Ralstonia pickettii is an emerging cause of nosocomial infection in patients particularly those with prolonged hospital stay and can cause invasive and severe infections.