Anti-mycobacterial activity of amikacin

We have tested in the IUTM egg medium the susceptibility against amikacin (AKC) of 147 strains of Mycobacterium tuberculosis (M.t.) isolated from the sputum of patients affected with pulmonary Tb. Only five strains showed resistance at 5 and 10 mcg/ml: they were also resistant to other main anti-tubercular drugs (MATD). The other 59 strains resistant to MATD and the 82 ones without any resistance to MATD were found normally susceptible to AKC at 5 mcg/ml in IUTM m. The parallel test performed on a synthetic medium (7H10) with 10 firstly-observed strains, allowed us to define that AKC undergoes a 60% inactivation in the egg medium. Two patients suffering from chronic pulmonary Tb, with M.t. constantly isolable in their sputum, assumed a twice-weekly treatment (TWT) with AKC alone (total 26 gr). This management induced in them improvement of the radiological and bacteriological findings, without alteration of the checking parameters.