Bilateral Necrotizing Fasciitis of the Foot Associated with Group B Streptococcus

Abstract

Necrotizing fasciitis (NF) is a severe bacterial infection involving fascia and subcutaneous tissue. It generally affects upper or lower extremities unilaterally, and there are few reports of bilateral-extremity NF. Here, we report a case of a 43-year-old male with type 1 diabetes who had NF on the left foot and subsequently developed NF on the other foot 1 week later. The patient survived with antimicrobial therapy and bilateral below-knee amputation. As group B streptococcus (GBS) was isolated by blood culture and culture of excised tissues of both feet, bilateral GBS NF of the foot was diagnosed. GBS is a rare causative pathogen in NF; however, there have been two case reports of bilateral GBS NF of an extremity in which NF appeared on the opposite extremity 1 week after the primary site infection, as in our case. GBS was isolated from cultures of blood and excised tissues of both extremities in both cases. Together, these observations suggest that GBS has a potential to cause secondary NF at remote sites by hematogenous dissemination with approximately 1 week delay and thereby lead to bilateral NF.

Emerging Group B Streptococcus Infection

“…GBS is a rare NF pathogen and has been reported in only 22 cases in English based literature [3], in which none of them is a burn patient. In the particular case of burns, the acute loss of tegument leads the skin and mucosa commensals to deep planes, in a previously healthy host.…”

“…Nevertheless the hypothesis cannot be ignored given all the favorable data and being so, our case is the first of its kind. In English literature there are only other 14 reported cases of GBS TSLS, half of which starting from NF and none of them in a burn patient [3][4][5][6][7]. Even if we consider the more frequent staphylococcal toxic shock syndrome (TSS) there are only two cases in adult patients with burns [10,11].…”

“…There are only 14 reported cases in Anglo-Saxon based literature of GBS TSLS, half of which starting from NF; none of them in a burn patient [3][4][5][6][7]. This article describes, to the author's knowledge, the first published case of TSLS by GBS in a severely burned patient starting from NF.…”

“…While group A Streptococcus pyogenes (GAS) is the most frequent agent of monomicrobial NF, group B Streptococcus agalactiae (GBS) is an emerging one with only few more than 20 cases described in English-based scientific literature [2,3]. It's postulated, although not proven, that GAS virulence factors were transfected to GBS giving it added virulence and the possibility of causing a streptococcal toxic shock-like syndrome (TSLS) vehiculated by superantigens [3].…”

“…It's postulated, although not proven, that GAS virulence factors were transfected to GBS giving it added virulence and the possibility of causing a streptococcal toxic shock-like syndrome (TSLS) vehiculated by superantigens [3]. In 1993, the Working Group on Severe Streptococcal Infection (WGSSI) formalized the criteria for GAS TSLS: a definite diagnosis made by GAS isolation in sterile media, signs, symptoms and typical laboratory abnormalities of septic shock; a probable diagnosis made by the latter and GAS isolation in a non-sterile site [4].…”