Campylobacter fetus of Reptile Origin as a Human Pathogen

Abstract

A Campylobacter species was isolated from blood from a febrile patient with precursor T-cell acute lymphoblastic leukemia, and after antibiotic treatment, a similar bacterium was isolated from blood 37 days later. Although phenotypic testing did not definitively identify the organisms, molecular analysis indicated that they were the same strain of Campylobacter fetus subsp. fetus and were of reptile origin. CASE REPORTA 20-year-old man presented to the hospital with a productive cough for 2 weeks and fever of 40.6°C for 1 day. Seven months earlier, a computerized tomographic scan of the chest showed a 7-cm-diameter mediastinal mass compressing the trachea. Peripheral blood flow cytometry at that time was diagnostic of precursor T-cell acute lymphoblastic leukemia. Because of pneumocystis pneumonia, which was treated, the patient then received trimethoprim-sulfamethoxazole prophylaxis three times a week on a continuing basis. Numerous courses of chemotherapy led to neutropenia, complicated by Candida tropicalis fungemia and then Streptococcus mitis bacteremia, which both resolved with treatment. Two weeks prior to admission, the patient received chemotherapy with methotrexate and 6-mercaptopurine.On the day the patient was admitted to the hospital, he reported worsening cough, fever, and epigastric pain. On examination, he appeared to be moderately ill with a temperature of 39.4°C, pulse of 110 beats/min, blood pressure of 110/48 mm of Hg, and respiratory rate of 14 breaths/min; his physical examination was otherwise normal. The leukocyte count was 3,900/mm 3 , with an absolute neutrophil count of 2,650/mm 3 and a platelet count of 52,000/mm 3 . He had 6.6 g of hemoglobin per dl. The chest X-ray was normal. After cultures were obtained, he was given cefepime intravenously. Two days after admission, one of four blood culture bottles was reported as growing Campylobacter species. Cefepime was changed to imipenem-cilastatin. He also was noted to have erythema and tenderness of the right arm in an area near a prior phlebotomy site. Vancomycin was added for presumed cellulitis and was continued for 1 week, with complete resolution of erythema. Multiple stool cultures (obtained after antibiotics were begun) were negative for Campylobacter species. Twelve days after admission to the hospital, the bloodstream Campylobacter isolate was noted to be resistant to trimethoprim-sulfamethoxazole but susceptible to levofloxacin, and the patient was discharged on oral levofloxacin (500 mg per day for 2 weeks).The patient recovered and was readmitted 3 weeks later for elective chemotherapy with cytarabine and etoposide. Four days after admission to the hospital, he developed abdominal pain and a temperature of 38.9°C. The chest X-ray was normal. After blood cultures were obtained, the patient was empirically treated with cefepime and metronidazole, which was changed 4 days later to intravenous levofloxacin and metronidazole. The absolute neutrophil count at that time was 11,300/mm 3 , which subsequently decreased to a nadir of Ͻ50...

Genetic Divergence of Campylobacter fetus Strains of Mammal and Reptile Origins

“…Of these 19 strains, 12 are type A, 6 are type B, and 1 is type A/B ( Table 1). Details of the characterization of these strains have been reported elsewhere (29,31,32,33). The strains were routinely grown on brucella broth (BBL Microbiology Systems, Cockeysville, Md.)…”

Bacteriemia por Campylobacter fetus subsp fetus en un paciente inmunosuprimido

“…6 Los sitios de recuperación de C. fetus reflejan la diversidad de cuadros clínicos posibles además de las bacteriemias y diarreas, incluyendo casos de meningitis, peritonitis, aneurisma "micótico" y artritis séptica entre otros. Las bacteriemias por C. fetus se concentran en pacientes con diabetes mellitus, cirrosis, o inmunocompromisos de diferentes causas tales como terapia corticoesteroidal, trasplante de órganos, infección por VIH o presencia de tumores sólidos o neoplasias hematoló-gicas 5,[7][8][9] . El riesgo de infecciones asociadas a corticosteroides depende de la condición de base, de la dosis diaria utilizada y/o de la dosis acumulada, apareciendo un mayor riesgo con dosis > 10 mg al día de prednisona o una dosis acumulada > 700 mg, tal como ocurrió en nuestra paciente 10 .…”

“…También se ha reportado ocasionalmente bacteriemias por C. fetus en hospederos inmunocompetentes 11 . Entre los factores de virulencia de C. fetus destaca la capacidad de resistir el efecto bactericida del suero, lo que explica su asociación con bacteriemias 9 .…”

“…La forma de adquisición de este microorganismo no fue dilucidada en este caso. Las infecciones C. fetus también han estado posiblemente ligadas al consumo de sopa de tortuga 9 , dietas naturistas que contienen extractos líquidos de vísceras crudas de animales 12 o a prácticas homosexuales 13 . Estudios previos desarrollados en Chile se han centrado en las especies C. jejuni y C. coli permitiendo establecer que el primero de ellos ocupa el tercer lugar como agente de diarrea de causa bacteriana en lactantes.…”

“…Con un tratamiento antimicrobiano apropiado, el pronóstico de las bacteriemias por C. fetus es en general favorable 5,7,9,11 . Sin embargo, es adverso en los raros casos de infección recurrente, los que no sobrepasan a 3% del total de las infecciones por esta especie 6,8 .…”