BACTERIAL WILT OF POTATOES : II-SENSITIVITY OF THE PATHOGEN TO ANTIBIOTICS AND PATHOGENESIS BY STREPTOMYCIN-RESISTANT MUTANTS

HABASHY, WADEA H. S.; FAWZI, FAIZA G.; EL-HUSEINY, TALAT M.; NEWEIGY, NASEM A.

doi:10.21608/ejar.1993.457479

BACTERIAL WILT OF POTATOES : II-SENSITIVITY OF THE PATHOGEN TO ANTIBIOTICS AND PATHOGENESIS BY STREPTOMYCIN-RESISTANT MUTANTS

Document Type : Original Article

Authors

¹ Agricultural Foreign Relation, Ministry of Agriculture, Dokki, Giza, Egypt

² Plant Pathology Research Institute, Agricultural Research Centre, Giza, Egypt.

³ Faculty of Agriculture-Moshtohor, Zagazig University , Egypt

10.21608/ejar.1993.457479

Abstract

Sensitivity of Pseudomonas solanacearum to antibiotics was test‌ed by the disk diffusion method. The eight isolates under investigation showed considerable variation against erythromycin and streptomycin, as well as low sensitivity to cephalosporin. No sensitivity could be de‌tected against penicillin at any concentration used. The least cidal concentration (LCC) of the afore-mentioned anti‌biotics and relative sensitivity (RS) of isolates were determined. Penicillin did not show any detrimental effect at the used concentrations, hence the recorded RS was zero. Cephalosporin showed low cidal effect as indi‌cated by high LCC and low RS. Considerable variation in sensitivity was observed in case of erythromycin and streptomycin; however, both showed high deterimental effect. The mode of action of antibiotics ei‌ther on protein synthesis or cell wall formation was considered. Mutants resistant to streptomycin (100 ug/ml) were tested for virulence. Resistant mutants produced earlier onset of the disease and more severe wilt symptoms as compared with the parent isolates. The use of streptomycin in bacterial wilt control is not recom‌mended. Further investigations on other antimicrobial agents are need‌ed.