Acute Myelogenous Leukemia with <i>Leptotrichia trevisanii</i> Bacteremia

Abstract

A 74-year-old woman visited an otolaryngology clinic with pharyngeal pain, and was diagnosed with a peritonsillar abscess. She received antibiotics and underwent incisional drainage, but displayed high white blood cell and blast cell counts, and was referred to our hospital. Gram-negative rods (Leptotrichia trevisanii) were detected in blood cultures performed on admission. She was diagnosed with bacteremia and acute myelogenous leukemia (FAB classification: M1). After antibiotic therapy, she temporarily recovered from the bacteremia, but subsequently died on day 34. Although Leptotrichia trevisanii bacteremia is extremely rare, clinicians should consider it in cases involving immunocompromised patients with oral lesions.

Leptotrichia species in human infections II

“…Description of Leptotrichiaceae is based on phylogenetic analyses of the 16S rRNA gene sequences. Leptotrichia species are facultative anaerobic/anaerobic Gram-negative rods that inhabit the oral cavity, intestines, urogenital system, and female genital tract of humans [1–5]. They are non-motile and ferment carbohydrates to produce various organic acids, including lactic acid, and traces of acetic, formic, or succinic acid, depending on the substrates and species.…”

“…buccalis was for centuries the only known Leptotrichia species, but new species have now been formally accepted, which include L. goodfellowii , L. hofstadii , L. shahii , L. trevisanii , and L. wadei (Figure 1) [2,4,5] and L. hongkongensis [6]. As with other members of the oral commensal microbiota, Leptotrichia species are also associated with periodontal diseases and oral cavity abscesses [5,7,8], typically as opportunistic infections. However, isolation of Leptotrichia species from infective endocarditis patients with normally functioning immune systems has been also reported [5,9–12].…”

“…As with other members of the oral commensal microbiota, Leptotrichia species are also associated with periodontal diseases and oral cavity abscesses [5,7,8], typically as opportunistic infections. However, isolation of Leptotrichia species from infective endocarditis patients with normally functioning immune systems has been also reported [5,9–12]. Leptotrichia species can cause opportunistic infections that lead to bacteremia in neutropenic patients with oral mucosal injuries [2,5] and bacteremia due to L. trevisanii after an allogeneic bone-marrow transplant [13].…”

“…However, isolation of Leptotrichia species from infective endocarditis patients with normally functioning immune systems has been also reported [5,9–12]. Leptotrichia species can cause opportunistic infections that lead to bacteremia in neutropenic patients with oral mucosal injuries [2,5] and bacteremia due to L. trevisanii after an allogeneic bone-marrow transplant [13]. Although systemic infections involving Leptotrichia species are infrequent, severe infections have been reported in immunocompromised patients [2,4,7,9,10,13–19].…”

“…Since previous reviews [2,3], Leptotrichia species have been reported in >124 cases [4,7,16,18–69,87–93], whereby 30 cases involved L. buccalis [4,8,15,21,34,52,56,70–79,87], 24 cases L. wadei [4,20,24,34,37,42,48,56,67,80,81,90,93], 16 cases L. trevisanii [4,5,9,10,13,14,17,37,87], 14 cases L. hofstadii [34,40,49,56,81–84,93], 10 cases L. goodfellowii [4,11,12,21,56,74,85,87], eight cases L. hongkongensis [4,6,18,45,47,56], and five L. shahii [34,56,86]. L. trevisanii and L. wadei bacteremia are extremely rare; clinicians should consider these species in cases involving immunocompromised patients with oral lesions [4,5,13,17,87]. The aim of the present review is to update the knowledge on the genus Leptotrichia as given in previous reports, adding information published after 2008 [2,3].…”