Arcanobacterium pyogenes Sepsis in Farmer, Brazil

To the Editor: Arcanobacterium pyogenes is a normal inhabitant of the mucous membranes of domestic animals, such as cattle, sheep, swine, and goats (1). Diseases caused by this agent have been reported for persons who live in rural areas and have underlying illnesses such as cancer and diabetes (2–4). A recent literature review (3), elicited by a case of A. pyogenes endocarditis, found 13 unequivocal cases of human infection with this agent; many patients had a history of close contact with domestic animals. However, septicemia was not reported. In June 2006, a 27-year-old im-munocompetent man was hospitalized in Campinas (São Paulo, Brazil) for fever, cough with purulent bloody sputum, and discharge from and pain in both ears. The patient was a farmer who lived in the rural Amazon area and had extensive contact with cattle and swine. For the past 3 days he had been taking amoxicillin, 1.5 g/ day, for chronic otitis media. At the time of hospital admission, his temperature was 38.9°C, respiratory rate 24 breaths/min, and blood pressure 100/70 mm Hg. He had palpable hepa-tosplenomegaly, but no murmur was detected in the precordium. Computed tomography (CT) scan of his chest showed multiple pulmonary nodules and alveolar infiltrates with small cavities suggestive of septic infarctions. Abdominal CT scan confirmed hepa-tosplenomegaly with focal lesions in the spleen. CT scan of the middle ear showed bilateral cholesteatoma and mastoiditis. No abnormalities were found during 2 transthoracic echocar-diography procedures. Laboratory values were PaO 2 63.4 mm Hg, hemo-globin 11.9 g/dL, thrombocytes 109 × 10 3 /mm 3 , leukocytes 11.05 × 10 3 /mm 3 with a left shift, serum albumin 2.6 g/dL, alanine aminotransferase 108 U/L, and total bilirubin 2.57 mg/dL. Blood and the ear secretion were submitted for culture. Cefepime was prescribed , 2 g/twice a day. Three blood cultures grew gram-positive bacilli, initially identified as Corynebacterium spp., sensitive to penicillin, ampicillin, ceftriaxone, gentamicin, clindamycin, vancomycin, and resistant to erythromycin, as determined by disk-diffusion test. Ear discharge culture grew Proteus mirabilis, sensitive to β-lactams, cephalosporins, and aminoglycosides. Subcultures of the gram-positive bacilli on sheep blood agar grew pinpointed, grayish, β-hemolytic colonies, identified as A. pyogenes by use of API Coryne 2.0 kit (bioMérieux, Durham, NC, USA; code 4732761). Although susceptibility standards are not available for this organism, it was considered susceptible to penicillin and ampicillin by combining the disk-diffusion test with the MICs, as determined by the Etest (0.06 …