Abstract
We describe a case of yellow grains actinomycetoma in the second toe of the left foot of Sudanese female caused by Micromonospora olivasterospora that does not match any known agent of this infection. The strain was identified as a Micromonospora olivasterospora based on the cultural and molecular techniques in combination with an updated taxonomy were successfully used to identify the yellow grain- producing bacterial Micromonospora olivasterospora as a new causative agent of human actinomycetoma. The clinical strain showed low MIC to doxycycline (0.5 µg/ml) followed by amikacin (4µg/ml), ceftriaxone (4µg/ml), trimethoprim/sulfamethoxazole (TMP-SXT) (≤ 2/38µg/ml), linezolid (8µg/ml), imipenem (≤ 13 µg/ml), and cefotaxime (≥ 14 µg/ml). In contrast, was not susceptible to minocycline (≥ 4µg/ml), amoxicillin-clavulanic acid (> 32µg/ml) and ciprofloxacin (≥ 21µg/ml). Therefore our patient received amikacin sulfate (15 mg/kg twice daily for 5 weeks), folic acid 5 mg once per day and trimethoprim/sulfamethoxazole (TMP-SXT) (co-trimoxazole 960 mg twice daily for 6 weeks); the cycles are repeated until the patient is cured. In conclusion: Updated taxonomy is essential to identify the new causative agents to the species level and is fundamental to elucidate the actinomycetoma associated with this unusual bacterial and to determine the appropriate therapy.