[Necrotizing subcutaneous infection by Streptococcus agalactiae].

Area of Science:

• Infectious Diseases
• Microbiology
• Dermatology

Background:

• Necrotizing soft tissue infections (NSTIs) are severe bacterial infections with high mortality.
• Streptococcus pyogenes is the most common causative agent of NSTIs.
• Prompt diagnosis and treatment are crucial for patient outcomes.

Observation:

• A case of NSTI caused by Streptococcus agalactiae (group B beta-hemolytic streptococcus) in an elderly male patient is presented.
• The patient had a history of chronic lymphatic leukemia and diabetes mellitus, increasing susceptibility.
• The infection involved the leg, presenting with rapidly progressing necrotic lesions.

Findings:

• The causative pathogen was identified as Streptococcus agalactiae, an uncommon cause of NSTI.
• Intravenous antibiotic therapy with amoxicillin-clavulanate and clindamycin was initiated.
• Clinical improvement, including resolution of necrotic lesions, was observed after treatment.

Implications:

• This case expands the spectrum of pathogens implicated in NSTIs.
• It underscores the importance of considering less common bacteria, like Streptococcus agalactiae, in NSTI diagnosis.
• Effective antibiotic regimens, including amoxicillin-clavulanate and clindamycin, can successfully manage these infections, even in immunocompromised patients.