Morphological, biochemical, and molecular identification of Curtobacterium flaccumfaciens isolated from Olea europaea trees

Abstract

Curtobacterium flaccumfaciens induces a bacterial wilt disease in many kinds of plants, including Olea europaea. The current study intends to isolate and identify C. flaccumfaciens, from the nodes of O. europaea based on morphological, biochemical and molecular features. The pure colonies were subjected to multiple tests included gram stain, motility, oxidase, catalase and antibiotic sensitivity. The findings showed that C. flaccumfaciens strains were motile gram-positive short rods, catalase-positive, oxidase-negative and catalase-positive. C. flaccumfaciens sensitivity against 9 antibiotics was tested using the disc diffusion method. The results revealed that the 5 strains varied in their antibiotic resistance pattern, however, SHGH3 strain is more sensitive to the antibiotics tested compared to the other strains and Meropenem is more efficient than others. The 16S rRNA sequences of the strains SHGH1, SHGH2, SHGH3, SHGH4, and SHGH5 strains were submitted to NCBI and given the accession numbers: OQ799009, OQ7990010, OQ799011, OQ799012, OR230004, respectively. Sequences showed a homology of (99.49%, 97.36%, 99.20%, 99.00%, and 99.32%,) with deposited sequences in GenBank carrying the accessions: KP898898, MT323132, KT614051, MK389451, and MN826580, respectively. The findings of the current study helps to better understanding C. flaccumfaciens in morphological, molecular, and biochemical aspects and shows for the first time the isolation of C. flaccumfaciens from the nodes of O. europaea.