In- vitro susceptibility of Mycobacterium tuberculosis to amoxicillin- clavulanate

The evidence of rapid spread of multidrug resistant Mycobacterium tuberculosis (MDR–TB) strains especially in high risk communities, persuade clinicians to find new drugs for this problem. b– lactams with few or no side effects has been reviewed as an alternative drugs for this issue. This study carried out to determine the effectiveness of amoxicillin–clavulanate in a group of Iranian patients. Amoxicillin–clavulanate was studied in five different minimal inhibitory concentrations (32- 512mg/ml) on 90 clinical strains of Mycobacterium tuberculosis (50 strains were sensitive and 40 were resistant to first- line anti-TB drugs). All strains were found resistant to amoxicillin–clavulanate in concentration of 32mg/ml. Only in concentration of 64mg/ml, sensitive strains (to first-line anti-TB drugs) were significantly more susceptible to amoxicillin–clavulanate than resistant strains. Five different MICs showed a non-significant difference in susceptibility to amoxicillin–clavulanate between strains with various resistance patterns to first-line anti-TB drugs. However, in 29 strains MIC were above 512mg/ml. Although amoxicillin–clavulante might be a suitable candidate as a second-line anti-TB drug, further clinical trials are required to draw a firm conclusion.