Myiasis-induced sepsis: a rare case report of Wohlfahrtiimonas chitiniclastica and Ignatzschineria indica bacteremia in the continental United States

Abstract

Rationale:The presentation of sepsis and bacteremia in cutaneous and cavitary myiasis is uncommon. We present a patient, residing in a temperate region of the United States, with myiasis and sepsis from the emerging human pathogens Wohlfahrtiimonas chitiniclastica and Ignatzschineria indica.Patient concerns:A 37-year-old male patient with an 8-month history of chronic lymphedema and ulcers of the lower left extremity presented with myiasis of the left foot and leg. The patient was initially seen by his family practitioner many times and was prescribed antibiotics which he could not afford. Debridement of the myiasis was not conducted by the family practitioner due to the belief that the patient's current state of myiasis would effectively debride and eventually heal the chronic ulcers along with multiple antibiotic regimens. Over the 8-month period, the patient developed a progressive, painful, necrotizing infection of his lower left extremity.Diagnoses:Physical examination clearly showed myiasis of the patient's lower left extremity, believed to be caused by Lucilia sericata (green bottle fly). Blood cultures revealed the presence of Providencia stuartii, W chitiniclastica, and I indica to be the underlying cause of sepsis and bacteremia.Interventions:All visible maggots were extracted, debridement of devitalized tissue was performed, and the leg ulcers were wrapped in pH neutral bleach. The patient was initially treated with a broad-spectrum antibiotic regimen of vancomycin, clindamycin, piperacillin, and tazobactam which, following clinical improvement, was de-escalated to cefepime.Outcomes:The fly larvae and maggots were removed from the extremity by scrubbing, pulse lavage, and filing away the callused tissue. Additionally, the patient's sepsis and bacteremia, caused by W chitiniclastica and I indica, were successfully treated through antibiotic intervention. Amputation was avoided.Lessons:The use of pulse lavage and chlorhexidine-soaked brushes for the removal of cavitary myiasis is an effective and minimally invasive procedure which does not cause additional damage to surrounding tissue. W chitiniclastica and I indica are emerging bacteria that have known association to parasitic fly myiasis in humans and are capable of causing sepsis and/or bacteremia if not accurately identified and treated promptly.

Ignatzschineria indica bloodstream infection associated with maggot infestation of a wound in a patient from Canada

“…In (7)(8)(9)(10)(11). The case presented here highlights this connection and is, to our knowledge, the second such case described in Canada (12).…”

“…Most clinical cases from Europe have described infection due to the species I. larvae and I. ureiclastica (9)(10)(11)13). In contrast, I. indica is the only species that has been reported in cases from the United States and Canada (8,12,14,15). All four Ignatzschineria spp have been isolated from the gut contents or larvae of flesh flies (Diptera: Sarcophagidae), but it remains unclear which fly larvae are predominantly associated with Ignatzschineria infections in humans (3,5).…”

“…Identification of Ignatzschineria spp in the clinical microbiology laboratory can be difficult. Commercial phenotypic identification systems may misidentify or fail to identify bacteria belonging to this genus (8)(9)(10)13,17,18). Bacteria that have been misidentified as Ignatzschineria spp include Acinetobacter lwoffii (VITEK 2 Combo, ID-GN card, bio-Mérieux), Acinetobacter lwoffii/Moraxella spp (VITEK 2, bioMérieux), Acinetobacter spp (VITEK 2, bioMérieux), Alcaligenes faecalis (RapidID NF Plus, Remel), Oligella ureolytica (VITEK 2 ID-GNB, bioMérieux), Oligella urethralis (API20 NE, bioMérieux), and Psychrobacter phenylpyruvicus (API20 NE, bioMérieux) (8)(9)(10)13,18).…”

“…Commercial phenotypic identification systems may misidentify or fail to identify bacteria belonging to this genus (8)(9)(10)13,17,18). Bacteria that have been misidentified as Ignatzschineria spp include Acinetobacter lwoffii (VITEK 2 Combo, ID-GN card, bio-Mérieux), Acinetobacter lwoffii/Moraxella spp (VITEK 2, bioMérieux), Acinetobacter spp (VITEK 2, bioMérieux), Alcaligenes faecalis (RapidID NF Plus, Remel), Oligella ureolytica (VITEK 2 ID-GNB, bioMérieux), Oligella urethralis (API20 NE, bioMérieux), and Psychrobacter phenylpyruvicus (API20 NE, bioMérieux) (8)(9)(10)13,18). In most cases of Ignatzschineria infection reported in the literature, organism identification has been made by molecular methods (most often 16S rDNA amplification and sequencing) (8)(9)(10)(11)13,17).…”

Maggot Wound Therapy Associated with Wohlfahrtiimonas chitiniclastica Blood Infection

“…Three were primarily treated with a cephalosporin [7,15,17] while two cases including this one had a quinolone in the regimen. There were nine patient reports that had W. chitiniclastica as part of a polymicrobial blood infection and most utilized a beta-lactam antibiotic [5,6,9,[11][12][13][18][19][20].…”