S3658 Liver, Lung, Brain Abscess 2/2 Strep Intermedius

Abstract

Introduction: Streptococcus intermedius is a beta-hemolytic, non-motile, catalase-negative, gram-positive member of the Streptococcus anginosus group (SAG) and also a member of normal human microbiota in the respiratory, gastrointestinal, and genitourinary tracts. S. intermedius has a unique tropism in the brain, liver, and lungs leading to abscess formation. Case Description/Methods: A 47-year-old male presented with a 5-day history of nonproductive cough, shortness of breath, pleuritic chest pain and progressively worsening fever/chills. He has a medical history of diabetes mellitus type 2. He denied nausea, vomiting, diarrhea, abdominal pain, headache, recent travel, or recent dental procedures. He denied alcohol use, smoking, and recreational drug use. Vital signs were stable. Labs revealed WBC 27.93, CRP 208, Procalcitonin 1.11, Ferritin 2,568. CT of chest/abdomen/pelvis with contrast revealed a large multiloculated right-sided pleural effusion versus empyema and multiple hepatic abscesses. Prior to broad-spectrum antibiotics the empyema and hepatic abscess were drained and cultures grew streptococcus intermedius and the patient was continued on IV ceftriaxone. On the day of discharge, the patient lost balance while walking and a head CT was obtained which identified multiple basal ganglia and right occipital lesions, with a follow-up MRI brain that confirmed ring-enhancing lesions concerning brain abscesses. These lesions were deemed inaccessible by neurosurgery and then treated as a hematogenous spread of streptococcus intermedius in the setting of recent bacteremia. Follow-up imaging confirmed the lesions to have decreased bin size prior to discharge. Discussion: S. intermedius release pro-inflammatory proteins as well as hydrolytic enzymes such as hyaluronidase and sialidase to induce tissue liquefaction and the formation of pus. S. intermedius is unique to the other bacteria in SAG due to the expression of intermedilysin (ILY), allowing it to cause cell necrosis with membrane bleb formation. The ILY gene is being used as a specific marker to detect S. intermedius via PCR. Risk factors include dental manipulation, sinusitis, diabetes, alcohol use, and malignancy. Treatment is based on susceptibility. An untreated liver abscess may lead to hematogenous spread which increases the risk for mortality. The mortality rate for SAG-associated bacteremia is 10-16%. Early recognition and timely intervention are important for successful treatment and improved outcomes.Figure 1.: One of the multiple hepatic abscess 2/2 strep intermedius.