Infectious Cellulitis Caused by Streptococcus halichoeri

Abstract

Infectious cellulitis is mainly caused by Streptococcus pyogenes or Staphylococcus aureus (1,2). Other less frequently isolated bacteria include Pasteurella from animal bites, non-typable streptococci or Bacillus anthracis in intravenous drug users, Vibrio spp. or Aeromonas spp. due to skin wounds in sea water (1, 2). We present here, to our knowlegde, the first human case of a cellulitis caused by a new pathogen, Streptococcus halichoeri. CASE REPORTAn 84-year-old man was hospitalized due to bacterial cellulitis of his left thigh in November 2015. His past medical history was marked by obesity, diabetes mellitus treated with gliclazide, insulin and metformin, dyslipidaemia treated with atorvastatin, hypertension treated with bisoprolol and perindopril, hyperuricaemia treated with allopurinol, atrial fibrillation, and prostatic adenocarcinoma treated with surgery and radiotherapy. Sixteen months earlier he had been hospitalized due to cellulitis in the same location. Streptococcus agalactiae was isolated from blood cultures. Cardiac ultrasonography revealed left-sided endocarditis and the patient was treated with parenteral amoxicillin (100 mg/kg) associated with gentamicin (3 mg/kg) for 15 days, followed by oral amoxicillin alone for one month. The outcome was favourable. An infected chronic ulcer of the left leg was thought to be the likely route of entry of infection.The new hospitalization, 16 months later, was marked by cellulitis of the thigh in the same location with persisting chronic ulceration of the left leg (Fig. 1). On admission, the patient's body temperature was 38.5°C, associated with a large erythematous skin plaque on his thigh consistent with bacterial skin cellulitis. The patient was treated empirically with intravenous amoxicillin (100 mg/kg). Blood cultures, and samples from the leg ulcer, grew non-haemolytic colonies on sheep-blood agar plates. Gramstaining revealed Gram-positive cocci, in chains. The identification results were discordant: S. pyogenes (91% probability) by VITEK ActaDV ActaDV Advances in dermatology and venereology Acta Dermato-Venereologica 379 Short communicationActa Derm Venereol 2018

Comparison of Streptococcus halichoeri isolates from canine and fur animal infections: biochemical patterns, molecular characteristics and genetic relatedness

“…A recent publication concerning infectious cellulitis in a human patient reported that a S. halichoeri "subsp. hominis" strain was resistant to ERY and CLI due to the presence of the ermB gene, and resistant to TET due to the tetO gene [7]. The ermB gene is frequent in streptococcal species such as S. pneumoniae [16].…”

“…Since then, it has been isolated from wild animals, including a European badger (Meles meles) with pyogranulomatous pleuropneumonia [2], and from the kidney of a dead Steller sea lion (Eumetopias jubatus) [3]. S. halichoeri has also been associated with severe human infections such as postoperative empyema [4], and from blood, wound and sinus infections [5], vulvar abscess and paronychia [6] and infectious cellulitis [7]. Due to phenoand genotypic differences between strains of animal and human origin, Shewmaker et al [5] suggested that this bacterial species should be divided into two subspecies: S. halichoeri subsp.…”

Pup mortality in New Zealand sea lions (Phocarctos hookeri) at Enderby Island, Auckland Islands, 2013-18

“…Recent cases published with associated details on pathology associated with infection with S . halichoeri , in a European badger ( Meles meles )[42] and several humans [43–45] showed similarities in presentation with the NZ sea lion pup case, often exhibiting suppurative respiratory lesions, sepsis and, in one case, cellulitis. S .…”

Streptococcal Infections in Marine Mammals

“…However, this was not tested. Another human infection was reported in 2018, where a man suffered from skin cellulitis due to S. halichoeri [118]. Shewmaker et al [119] compared human and seal strains and concluded two subspecies S. halichoeri subsp.…”