RESUMO
Leuconostoc species, which are the members of Streptococcaceae family, have recently been recognized as potential pathogens. They usually cause infections in patients with underlying disease, with venous catheters or previously treated with vancomycin. In this report, we have presented two cases of Leuconostoc bacteremia. The first case was a 42 years old male patient who was diagnosed to have colon adenocarcinoma. He had undergone colon, stomach and distal pancreas resection operation and had given chemotherapy. Blood and catheter cultures yielded methicillin-resistant Staphylococcus aureus. Blood cultures were repeated since teicoplanin therapy had failed, and Gram positive cocci resistant to vancomycin were isolated. The other case was a 26 years old male patient who had undergone a shunt operation because of pineal lesion and hydrocephaly. He had given ampirical vancomycin therapy since he had post-operative high fever, however the therapy had failed. The catheter culture yielded Gram positive cocci resistant to vancomycin. Both isolates were identified as Leuconostoc spp. with API 20 strep identification kit (Bio Merieux), and both of them were found sensitive to penicillin, ampicillin, clindamycin, gentamicin and chloramphenicol, while they were resistant to teicoplanin and vancomycin. The patients were successfully treated with clindamycin. It is concluded that, Leuconostoc spp. should be considered when vancomycin-resistant organisms resembling streptococci are isolated from blood cultures.