The seed-borne bacterial diseases of family solanaceae cause significant economic losses worldwide. In the present study, fourteen bacterial isolates were recovered from seeds of different varieties of tomato, eggplant, black nightshade and tobacco.  The seed samples were collected from different locations in Egypt. Isolated bacteria were identified based on morphological, physiological and biochemical tests as well as colonial morphology aspects on the differential medium, yeast extract dextrose calcium carbonate (YDC) besides the selective media (PA 20, King's B and Tween B). Pathogenicity of the isolated bacteria was assessed for causing graywall, bacterial speck and bacterial spot symptoms on tomato seedlings. Disease symptoms were recognized on leaves and stems of the inoculated seedlings. Re-isolation from collected seeds of the inoculated tomato plants was performed. Results indicated that Pantoea spp. was an endophytic bacteria, Pseudomonas spp. was an epiphytic bacteria, while Xanthomonas spp. was both epiphytic and endophytic bacteria. Furthermore, cellular fatty acids composition were identified and quantified to give a profile for tested bacterial isolates. Moreover, the bacterial isolates were identified at the molecular level via PCR reactions utilizing the 16S rRNA gene. Partial DNA sequences were analyzed using BLAST tool revealed that the inferred 16S rRNA partial sequences of the 7 isolates  showed similarity to Pantoea ananatis (3 isolates), Pseudomonas syringae pv. tomato (2 isolates) and Xanthomonas vesicatoria (2 isolates). To the best of our knowledge the bacterium associated with the graywall seems to be first report of P. ananatis isolated from tomato fruits and black nightshade seeds in Egypt.

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A survey of the occurrence of strains of Erwinia amylovora resistant to streptomycin in certain Egyptian pear orchards was earned out during April and May 1988. Twenty‐two isolates out of 604 isolates collected from 11 orchards showed resistance to streptomycin. All the streptomycin resistant (Strr) strains isolated in the present work were resistant to high levels of streptomycin with minimal inhibitory concentrations ranging from 1000 to 3000 μg/ml. The occurrence of Strr strains in Egypt is still limited and the population of resistant strains was at relatively low level. However, such occurrence of E. amylovora with resistance to streptomycin is a potentially serious situation.

Bacterial metal reducers were isolated from water samples collected from harsh condition locations in Egypt. Four selected isolates were identified as Enterococcus thailandicus, Pseudomonas putida, Marinobacter hydrocarbonoclasticus, and P. geniculata for Copper (Cu), Iron (Fe), Cobalt (Co) and Zinc (Zn) Nanoparticles (NPs) production sequentially. Nitrate reductase enzyme was assayed for bacterial isolates which demonstrated that P. putida, and M. hydrocarbonoclasticus have the maximum enzyme production. The produced NPs were characterized by using XRD, TEM, UV–VIS spectroscopy. Magnetic properties for all selected metals NPs were measured using Vibrating Sample Magnetometer (VSM) and demonstrated that FeNPs recorded the highest magnetization value. The antibacterial activity of selected metals NPs was tested against some phytopathogenic bacteria causing the following diseases: soft rot (Pectobacterium carotovorum, Enterobacter cloacae), blackleg (Pectobacterium atrosepticum and Dickeya solani), brown rot (Ralstonia solanacearum), fire blight (Erwinia amylovora) and crown gall (Agrobacterium tumefaciens). All metals NPs showed an antagonistic effect against the tested isolates, particularly, FeNPs showed the highest antibacterial activity followed by CuNPs, and ZnNPs. Due to the small size, high reactivity, and large surface area of biologically synthesized NPs, they are used as a good disinfector, and can be considered as a new and alternative approach to traditional disease management methods.

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