A patient presents with fever for 3 weeks. On examination he is observed to have splenomegaly. Ultrasonography reveals a hypoechoic shadow in spleen near the hilum. Gram negative bacilli are isolated on blood culture. Which of the following is the most likely causative organism ?

Splenic Abscess Unusual but potentially life threatening illness Moality rate of 15-20% in previously healthy patients with single unilocular lesions, to 80% for multiple abscesses in immunocompromised patients Predisposing factors for Splenic Abscess Malignancies Polycythemia vera Endocarditis Prior trauma Hemoglobinopathies Urinary tract infections IV drug use AIDS Approximately 70%of splenic abscesses result from hematogenous spread of the infective organism from another location, as in endocarditis, osteomyelitis, and IV drug use Gram-positive cocci (Staphylococcus-MC, streptococcus, or Enterococcus spp.) and gram-negative enteric organisms are typically involved Salmonella and Enterobacter spp. and other enteric organisms are commonly seen in splenic abscess in patients of sickle cell anemia Fungal abscess (e.g., Candida spp.) also occur, typically in immunocompromised patients Clinical features: Splenic abscesses present with nonspecific symptoms: vague abdominal pain, fever, peritonitis, and pleuritic chest pain Splenomegaly is not typical Diagnosis CT: Investigation of choice for diagnosis of splenic abscess USG: Diagnosis can also be made with ultrasound Treatment: Unilocular abscesses: Percutaneous drainage + antibiotics (success rates 75-90%) Multilocular lesions: Splenectomy + Drainage of the left upper quadrant + Antibiotics Ref: Sabiston 20th edition Pgno: 1564