Streptococcus intermedius: unusual presentation and complication of lung abscess

We report a case of a 54-year-old immunocompetent male who had lung abscess secondary to Streptococcus intermedius that led to discitis by contiguous spread of infection. He initially presented with constant chest pain for 6 weeks that radiated to lower back, with no fever, chills or weight loss. He denied smoking cigarettes, alcohol use or any illicit drug. On investigation, a mass was identified on the posterior medial aspect of the right lower lobe with direct infiltration into right side of the T5–T6 vertebral bodies. Histopathology identified organising pneumonia with abscess. Tissue cultures showed S. intermedius, and were negative for other microorganisms. This case highlights a rare presentation of S. intermedius discitis by contiguous spread of infection from posterior right lower lobe lung abscess. S. intermedius usually occurs in older patients with pulmonary infections complicated with pleural effusion or lung abscess, but can present in young patients with no clear symptoms of lung infection, like our patient.

Extensive Parapharyngeal Abscess in a 4-Month-Old Infant

Parapharyngeal abscess in an infant is a very rare condition. We present the case of a 4-month-old girl with large masses on the neck’s left side. Computed tomography showed an extensive parapharyngeal abscess. Left tonsillectomy was performed under general anesthesia from a transoral approach, followed by an incision and evacuation of the abscess from the parapharyngeal space. Microbiological analysis identified a massive occurrence of Streptococcus intermedius.

Case Report: Subtherapeutic Vancomycin and Meropenem Concentrations due to Augmented Renal Clearance in a Patient With Intracranial Infection Caused by Streptococcus intermedius

Streptococcus intermedius occasionally causes brain abscesses that can be life-threatening, requiring prompt antibiotic and neurosurgical treatment. The source is often dental, and it may spread to the eye or the brain parenchyma. We report the case of a 34-year-old man with signs of apical periodontitis, endophthalmitis, and multiple brain abscesses caused by Streptococcus intermedius. Initial treatment with meropenem and vancomycin was unsuccessful due to subtherapeutic concentrations, despite recommended dosages. Adequate concentrations could be reached only after increasing the dose of meropenem to 16 g/day and vancomycin to 1.5 g × 4. The patient exhibited high creatinine clearance consistent with augmented renal clearance, although iohexol and cystatin C clearances were normal. Plasma free vancomycin clearance followed that of creatinine. A one-day dose of trimethoprim–sulfamethoxazole led to an increase in serum creatinine and a decrease in both creatinine and urea clearances. These results indicate that increased tubular secretion of the drugs was the cause of suboptimal antibiotic treatment. The patient eventually recovered, but his left eye needed enucleation. Our case illustrates that augmented renal clearance can jeopardize the treatment of serious bacterial infections and that high doses of antibiotics are needed to achieve therapeutic concentrations in such cases. The mechanisms for regulation of kidney tubular transporters of creatinine, urea, vancomycin, and meropenem in critically ill patients are discussed.