A Case of Beta-Hemolytic Streptococcal Group C Bacteremia, Necrotizing Pelvic Infections and Multiple Septic Emboli Mimicking Endocarditis

Abstract

We describe 29-year-old man presenting with streptococcal group c bacteremia, extensive necrotizing soft tissue involvement and multiple septic emboli. Our case is interesting in how it mimicked endocarditis because of the finding of pulmonary septic emboli on CT scan, when Transthoracic and Transesophageal Echocardiogram didn’t show any vegetation and the source may have been a pelvic septic phlebitis though not noted on the CT scan.

Introduction

Beta-Hemolytic Streptococcal Group C Bacteremia in a paraplegic intravenous drug abuser (IVDA) with gluteal decubitus ulcers.

Case Description

A 29 year old paraplegic male with a history of active IVDA (heroin), asthma, Diabetes Mellitus type 2, presented to ER complaining of nausea, vomiting, abdominal pain, tactile fever and foul smelling urine for 3 days.

Physical exam revealed bilateral flaccid paralysis of lower extremities (2º to a gunshot wound to lower thoracic spine 6 years ago), IV marks on both arms, left sided gluteal decubitus ulcer 3×2 cm with tunneling and no discharge, erythema or signs of infection.

Labs were significant for hyponatremia (126mEq/L), hyperglycemia (424mg/dL) with anion gap (16) and positive ketones. ABG showed metabolic acidosis (pH 7.37, HCO3 19 and lactic acid 2.4mEq/L). U/A showed elevated WBC (42,000/mL) and few bacteria.

With the impression of Diabetic Ketoacidosis secondary to noncompliance and Urinary Tract Infection, the patient was admitted and started on insulin and Ciprofloxacin. On the second day of admission he became hypotensive, tachycardic and developed septic shock. He was started on Vancomycin, Piperacillin/Tazobactam, vasopressors and insulin drip. Blood cultures revealed Streptococcus beta-hemolytic group C. Penicillin G and Gentamycin were started and Vancomycin and Piperacilin/Tazobactam discontinued. CT chest C(-) showed multiple peripheral lung nodules without cavitations compatible with septic emboli (Fig 1). ^{[fig. 1]}

His hepatitis serologies revealed the presence of HBcAb and HBsAb and HCVAb but were negative for HBsAg. Transesophageal and Transthoracic Echocardiogram to rule out endocarditis didn’t show any vegetation.  Urine culture revealed yeast like organisms and Fluconazole was started. On the 11th hospital day his temperature increase to 104ºF, his hematocrit dropped to 20.6 and he developed septic shock. On physical exam his decubitus now had a purulent discharge. His antibiotics were changed to Vancomycin, IV Metronidazole and Amikacin and higher dose of Fluconazole. His repeated blood cultures grew MRSA and group C streptococcus and his decubitus drainage grew MRSA, Group C streptococcus and Klebsiella. A urine culture grew Candida kruseii. His CT chest/abdomen/pelvis C(+) showed: bilateral lung nodules now with cavitations, left hip septic arthritis with osteomyelitis involving the left acetabulum and ischium, air throughout the soft tissues overlying the left pelvis and intraperitoneal abscesses of left pelvis (Fig 2).

Total Body Gallium Scan showed intense focal uptake in the soft tissue and bony structures of left pelvis and hip. CT of left hip and thigh showed large left hip abscess and suprapatellar joint effusion.

The patient underwent extensive incision and drainage with debridement of the sacral wound with excision of loose bone shards of the pelvic rami, incision and drainage of the anterior abdominal wall abscess and a diverting colostomy was performed. Antibiotics were changed to Linezolid, Amikacin, Metronidazole, Piperacillin/Tazobactam and Eraxis. The bone pathology revealed dead bone and osteomyelitis. Cultures from the operative procedures grew MRSA and Candida glabrata. Antibiotic treatment was changed to Vancomycin, Piperacillin/Tazobactam and Caspofungin to complete at least a 6 week course total with clinical and radiologic follow-up.

Discussion

Group C streptococci (GCS) are typical Gram positive cocci in chains, facultative anaerobes that are widely distributed in animals but are also part of the normal human flora. Underlying medical conditions of patients with group C infections include cardiovascular disease, diabetes mellitus, cirrhosis, chronic alcoholism, bone and joint disease, dermatologic processes and also immunocompromised states. In a 1989 review of CWRU School of Medicine Cleveland, Ohio of Group C infections over 15 years, it was shown that major risk factors in cases of Strep C bacteremia included chronic cardiovascular disease, malignancies, diabetes and chronic alcoholism. ^{1 2}  Echocardiography or transesophageal echocardiogram in these cases should be performed to exclude endocarditis. ^{3 4 5} Our case is interesting in how it mimicked endocarditis because of the finding of pulmonary septic emboli on CT scan, when the source may have been a pelvic septic phlebitis though not noted on the CT scan of the pelvis. Group C streptococci have also been implicated in cases of necrotizing fasciitis, myositis, and pyomyositis (as was true in our patient) and clinical presentation, treatment or outcome doesn’t differ much from Group A or Group B streptococcal bacteremia. ⁶ Streptococcal toxic shock has been a complication of soft tissue infections caused by these organisms.

It is important to consider GCS in cases of bacteremia with extensive necrotizing soft tissue involvement and to look for necrotizing soft tissue infection when GCS bacteremia is identified.