Splenectomized patient with fatal DF-2 septicemia

Case Report Splenectomized Patient with Fatal DF-2Septicemia Submitted by Frances Boyce, MT (A.S .C.P.), R. F. Price, M.D. This 22-year-old male with a history of prior traumatic splenectomy was in his usual state of good health until 2% days prior to admission, when he sustained a dog bite on the dorsum of his right hand as he was separating two fighting domestic dogs. Two days prior to admission, he exhibited slight fever. One day prior to admission he was febrile with fever to 105" F. On this day, he was given an injection of penicillin (1.2 million units) by his family physician. Four to five hours prior to admission, he began vomiting, had increased fever, and marked fatigue. At admission, the patient presented with tachycardia and ecchymoses about the nose and cheeks. The patient's blood pressure was 90/60 mrn of Hg and his temperature was 102" F. There were no focal neurologic signs. The patient's extremities exhibited marked vasoconstriction, and there was moderate swelling of tissue about the bite wound. The white blood'cell count was 5200/mm3. Examination of the blood smear, prepared for differential counting of leukocytes, revealed the presence of both intra- and extracellular bacilli. The patient was treated empirically with cefazolin, chlorarnphenicol, and tobramycin. Subsequent white counts were in the 20,000 to 25,000/mm3 range. The ecchymoses increased, and coagulation parameters revealed disseminated intravascular coagulation (DIC) characterized by prolonged prothrombin time, partial thromboplastin time, low fibrinogen level, and fibrin split products greaterthan 40pg/ml. The platelet count was 19,000/mm3.The initial hematocrit was 50, but during the course of hospitalization this fell to 31 secondary to bleeding from multiple venipuncture sites, GI melena, and hemoptysis. Intravenous fluids were given, as were units of whole blood, platelets, and fresh frozen plasma. The patient's renal function quickly deteriorated with essentialIy no urine output.

Approximately 20 hours after admission, the respiratory rate increased to greater than 50, with marked dyspnea. The patient went into ventricular tachycardia and then asystole. Cardiopulmonary resuscitation was performed without significant response. Final diagnosis was respiratory arrest, secondary to overwhelming gram-negative sepsis, with the following complications: hypotension, renal insufficiency, severe metabolic acidosis, DIC, and bleeding from multiple organ systems.

Bacteriology A smear of the patient's blood drawn for hematologic studies was grarnstained and showed multiple small pleomorphic intra- and extracellular gramnegative rods. Two blood cultures were drawn into blood culture bottles that contained 100 ml of Trypticase soy broth, supplemented with sodium polyanethol sulfonate. After 24 hr incubation, these bottles were subcultured to chocolate agar plates and incubated at 37°C in 7% COz. A small grey colony appeared on the subculture plate on the fourth day of incubation. Routine biochemical tests were inoculated, but failed to support the growth of the bacterium. The organism was then sent to the Washington State Health Department, and identified as DF-2. The following biochemical reactions were noted. Biochemical Test

Reactiorz

When 17 patient isolates of DF-2 were examined, each grew slowly on blood agar, and growth was enhanced by cultivating the organisms in an atmosphere of increased COz (3). The organisms were all susceptible to penicillin, chloramphenicol, tetracycline, and carbenicillin (3).

Summary A recently recognized organism, DF-2, is known to cause fatal infections in persons whose immunologic defenses are weakened by chronic illness or splenectomy (1). There is some evidence that these fastidious organisms may be part of the normal oral flora of dogs and may be transmitted to humans by bites and scratches (2, 3). The clinical and pathological features of this infection are indistinguishable from those caused by other bacteria, but the immunosuppressed or splenectomized patient should be considered at special risk to DF-2. The small number of reported cases of disease caused by DF-2 may be due to the organism's slow rate of growth; many laboratories may discard blood subculturesafter 48 hours. Microbiologists' awareness of this organism, notification by physician of a suspected case, and routine Gram's stains on blood cultures may show an increased prevalence of DF-2 bacteremia. References 1. Butler, T . et al. 1977. Unidentified gram

negative rod infection. Ann. Int. Med. 86: 1-5.

Glucose Lactose Maltose Mannitol Sucrose Xylose Indol Citrate MRNP Urea Nitrate Gelatin Esculin Hydrolysis Oxidase Catalase Hernolysis Motility TSI

Acid with no gas

Acid with no gas Acid with no gas Negative Negative Negative Negative Negative NegativeINegative Negative Negative Negative Weak Positive Positive Positive Alpha Negative No growth

'hlost performed in serum supplemented media.

2. Boile, W. E., E. C. Stowe, and A. M. Schmitt. 1978. Aerobic bacterid flora of

oral and nasal fluids of canines with reference to bacteria associated bites. J. Clin. Microbial. 7:223-231. 3. CDC. March 1979. An odd link between

dog bites and patients with splenectomy. CDC Veterinary Public Health Notes.