Elizabethkingia meningosepticum: an emerging nosocomial pathogen in a critical patient with septicaemia

Abstract

SummaryWe describe a case of sepsis due to the non-fermenter Gram-negative bacillus Elizabethkingia meningosepticum in a patient (M, 23 y.o.) hospitalized at the Intensive Care and Critical Care Medicine suffering of a severe neurological disease and acute surgical abdomen, caused by suppurative peritonitis secondary to PEG removal. Two sets of blood cultures were collected at the time of persistent fever. The culture on chocolate and blood agar showed the presence of colonies with characteristic grey-shiny appearance and 1-2 mm in diameter. No growth was instead evident on Mac-Conkey agar. The Gram stain was performed, but the final identification of the isolate as E. meningosepticum was obtained by Vitek2 System, on the basis of growth characteristics, biochemical reaction results, and the peculiar antibiotic susceptibility profile. The identification was also confirmed by Vitek MS MALDI-TOF mass spectrometry instrument (bioMérieux, Marcy-l'Étoile, France). Results of susceptibility testing highlighted the resistance to most antibiotics useful against Gram-negative bacteria and a paradoxical susceptibility to those targeting mainly Gram-positives. The vancomycin and ciprofloxacin combined therapy improved the patient's conditions, with a complete resolution of the E. meningosepticum bacteraemia. Unfortunately, due to the onset of important clinical and surgical complications, the patient died as a result of a septic shock caused by a MDR Acinetobacter baummannii. The present work underline the importance of correct species identification in the case of E. meningosepticum, a rare bacterium whose unique antimicrobial susceptibility pattern, require an ad hoc therapeutic approach. IntroductionElizabethkingia meningosepticum is a non-fermenter Gram-negative bacillus isolated for the first time in 1959 by the American bacteriologist Elizabeth King, who studied nonclassified bacilli related to childhood meningitis. The bacterium, initially classified as Flavobacterium meningosepticum, was re-classified as Cryseobacterium meningosepticum in 1994 and subsequently, after phylogenetic studies, definitely categorized as E. meningosepticum in 2005 (3, 9, 8).Widespread in nature (fresh water, salt water, or soil), is an aerobic, non-fermenter, non-spore-forming and non-mobile, saprophiticus ubiquitous bacillus. Unlike many other non-fermenter bacteria (Flavobacterium and Cryseobacterium), E. meningosepticum grows well at 37°C on blood agar and chocolate agar (4, 7). The colonies appear very pale yellow or more often not pigmented (dissimilarly to all Chryseobacterium species, that produce a not diffusible yellow-orange pigment); their growth is not easily appreciable after 24 hours of incubation (1). The grey colour of the colonies on blood agar is due to protease and gelatinase production. They grow poorly on MacConkey agar and are unable to grow on colistin-nalidixic acid (CNA) agar due to the susceptibility to quinolones such as nalidixic acid (6,10,14).E. meningosepticum has a characteristic resistance to most antibio...

Elizabethkingia Meningoseptica’ya Bağlı Bir Neonatal Bakteriyemi Olgusu

“…tarafından yapılan bir çalışmada, yenidoğan yoğun bakım ünitesinde meydana gelen bir salgında intravenöz beslenme sıvılarının enfeksiyon kaynağı olduğu belirtilmiştir(3). Nadir bir hastane enfeksiyonu etkeni olmakla birlikte özellikle son on yılda E. meningoseptica'ya bağlı nozokomiyal enfeksiyonlarda artış tespit edilmiştir (9). E.meningoseptica'nın bulaş yolu, virülans faktörleri, etkili tedavi rejimleri ve antimikrobiyal direnç paternleri hakkında henüz yeterli bilgi bulunmamaktadır (8)…”