A CASE SERIES OF COMPLICATED PANTOEA DISPERSA BACTEREMIA: IS PANTOEA SPECIES ANOTHER PANDORA'S BOX?

Abstract

Intro: Pantoea sp is a non-encapsulated, ubiquitous Gram-negative rod organism isolated from ecological sources such as plant surfaces, human feces, and the environment, and has been reported to cause respiratory infections, neonatal sepsis, and bloodstream infections. Methods: We report 2 cases of Pantoea dispersa bacteremia with different presentations. The organism was identified using MALDI-ToF and 16s ribosomal RNA. Pantoea dispersa isolated for both patients showed similar antibiotic susceptibility profile. Findings: Case 1: A 55 year old diabetic man presented with 2-day history of fever and vomiting and diabetic ketoacidosis; initial blood culture revealed Pantoea dispersa, and incidental findings of liver abscess on ultrasound abdomen and treated with iv ceftriaxone for 6 weeks with clinical resolution. Case 2: A 30 year old pregnant lady at 27 weeks presented with breathlessness and thyroid storm; clinical examination revealed poor oral hygiene and dentition and blood culture showed Pantoea dispersa. Transthoracic ECHO revealed severe thickened mitral valve with mitral regurgitation and was treated as infective endocarditis with iv ceftriaxone for 4 weeks. Discussion: In both cases, blood culture was positive for Gram negative rods and grew umbilicated yellow pigmented colonies on blood agar and pale pink umbilicated colonies on MacConkey agar. Identification by Matrix-assisted laser desorption/ionization time-of-flight (MALDI-ToF) mass spectrometry analysis identified the organism as Pantoea dispersa with (log) score of ≥2.0 indicating high confidence identification. The identification was corroborated by 16s ribosomal RNA. Antimicrobial susceptibility testing following Clinical and Laboratory Standards Institute criteria for Enterobacterales, revealed all antimicrobials tested were susceptible. Conclusion: The epidemiology and clinical features of Pantoea dispersa are still unknown. With the development of MALDI-ToF mass spectrometry in routine laboratory practice more cases of Pantoea dispersa may be identified. Clinicians must know that a variety of infections caused by Pantoea dispersa could occur in immunocompromised as well as immunocompetent patients.