Author(s):

Mohsen Hashim Risan

Abstract: The present study was aimed for molecular identification of aminoglycoside phosphotransferase (aph) gene from Streptomyces spp. Six soil samples were collected randomly from different location of Baghdad city. Nine Streptomyces isolates were selected and purified on Glycerol yeast extract agar (GYEA). The isolates were identified as Streptomyces spp. based on their morphological, physiological and biochemical characteristics as described in the International Streptomyces Project. All Streptomyces isolates were screened for their antibacterial activity on malt extract yeast extract agar medium (ISP2) using scross-streak technique. A broad spectrum of antibacterial activity was observed in 44.4% (4 out of 9) (A3, A4, A15 and A17) against all tested pathogens. Four isolates were positive in the PCR technique. Performing PCR reactions using primer pair on DNA from soil isolates produced a single 273 bp band in all tested isolates. The results of aph gene detection clarify that one isolate (25%) of Streptomyces isolates gave a positive result and carrying aph gene while 3 (75%) of Streptomyces isolates were lack the gene and no cross reactivity could be observed with any of the A3, A4 and A15 isolates. A17 isolate gave DNA bands 1190 bp in length. The results indicated that the A17 isolate is very close to the species Streptomyces fradiae responsible for producing antibiotic neomycin.

Pages: 175-182  |  2020 Views  298 Downloads

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