Antibiotic resistance / susceptibility of 30 isolates of Bacillus anthracis isolated in Iran between 2007 and 2008

Thirty isolates of Bacillus anthracis recovered from animal carcasses, soil and human in different localities in Iran between 2007 and 2008. They were tested by standard disc diffusion susceptibility method for their resistant/ susceptibility to different kinds of antibiotics. According to American National Committee of Clinical Laboratory Standards (NCCLS) guidelines all isolates were sensitive to levofloxacin (100%), cefixime (100%). Other isolates showed different kinds of sensitivity to: doxycycline (96.7%), cephalothin (95.6%), ampicillin (95.6%), nitrofurantoin (95.6%), tetracycline (94.4%), ofloxacin (89.9%), gentamycin (77.8%), nalidixic acid (72.2%), kanamycin (75.6%), erythromycin (71.1%), piperacillin (78.9%), tobramycin(64.4%), choramphenicol (59.9%), cefotaxime (33.3%), ciprofloxacin (1.1%), cefuroxime (33.3%), azithromycin (44.4%), streptomycin (55.6%), ticacillin (35.6%), rifampicin (34.4%), clindamycin (74.4%), ceftriaxon (26.7%), methicillin (55.6%), trimethoprim (8.9%), cloxacillin (31.1%) and penicillin(74.4%). One of the isolates was complete reistance to penicillin.Therefore, preventive and therapeutic strategies involving the use of antibiotics should take the possibility of resistance and/or susceptibility of the isolates into account and not decided without antibiotic sensitivity testing.