Castello, L*.; Sandor, A.; De Paulis, A. N.; Paimitano, J.; Santoianni, J.E.; Predari, S.C.
Instituto de Investigaciones Médicas "A. Lanari" - Facultad de Medicina - Universidad de Buenos Aires. Argentina.
Fusobactenum mortiferum is a gram-negative anaerobic bacillus, mainly encountered in patients with intra-abdominal infections, although it is infrequently isolated from liver abscesses (LA). A 23 years-old man in hemodialysis since May 1994, was admitted on October 19%, with fever and chills for one week, malaise and a few episodes of diarrhea. Laboratory: WBC 11,300 /mm3, GOT x2 and GPT x5. Serum alkaline phosphatase, Sy GT, and bilirubin had normal values. Antibody-titres were - for HIV and CMV; + for HCV. HBsAg was -. Four sets of blood cultures (aerobic and anaerobic bottles), and 2 sets through the arterio-venous fistula (AVF), were done. On November 1st, the patient (pt) presented abdominal pain at the right flank and temperature up to 40°C. A diagnostic ultrasound and computarized axial tomography demonstrated multiple LA. The specimen obtained by percutaneous needle aspiration-drainage of one abscess, was cultured. A laparotomy did not find the source of the LA, neither previously undiagnosed diseses, nor complications of bacterial LA. From all blood cultures and the abscess, it was recovered an anaerobic gram-negative rod with a marked pleomorphism and round bodies. All the strains were identified as Fusobactenum mortiferum : on horse Brucella-agar (with vitamin K1 and hemin ) 48 h. old-colonies were 1-2 mm in diameter, semitranslucent; non haemolytic. Biochemical characteristics: vancomycin-R (5 ug disk), bile disk-R, brilliant-green disk-R, but colistin-S (10 ug disk) and kanamycin-S (1 mg disk). Growth on BBE agar +, lipase on EYA plate -, indole -, nonmotile. Glucose, fructose, mannose, cellobiose, lactose, maltose, sucrose and trehalose, were fermented. It did not ferment arabinose, marmitol and salicin. Growth in 2O% bile and esculin hydrolysis were +. Urease was not produced, and nitrate was not reduced. The strain was susceptible to penicillin G, imipenem, piperacilin, clindamycin, cephalotin, cefoxitin, chloramphenicol, and metronidazole, by broth disk elution metdod, and MICs (agar-dilution technique). The ß-lactamase test (Nitrocefin) was -. Inital therapy: ampicillin/sulbactam 6 g/day plus ciprofloxacin 500 mg/day i.v. Definitive scheme: ampicillin 2g/day plus ciprofloxacin 500 mg/day p.o. to complete 3 months. The pt had a successful recovery. Commentaries: 1. It is important to keep in mind the presence of LA, when anaerobes are recovered on blood cultures, in case of fever of unknown origin. 2. The celerity in clinical and bacteriological diagnosis, adequate and prolonged antibiotic therapy, are prioritary in the prognosis of a pt with multiple LA. 3. The source of these bacterial abscesses remained unknown. 4. The immunosuppression characteristic of the chronic renal failure condition, contributed to the pt illness.