n rahimifard department of microbiology, food and drug laboratory research center (fdlrc), tehran, iran tel: +98 – 912 - 1032806, fax: +98- 21- 66417252 h hajimehdipoor department of microbiology, food and drug laboratory research center (fdlrc) b pirouz department of microbiology, food and drug laboratory research center (fdlrc) f bagheri department of microbiology, pharmaceutical sciences branches, islamic azad university o bagheri molecular biotechnology research center, baqiatalah university of medical sciences ks mirdamadi department of microbiology, pharmaceutical sciences branches, islamic azad university