Isolation, Identification and Antimicrobial Activities of Four Bacteria Associated with Entomopathogenic Nematodes, Steinernema spp.

Recently, the search for novel products derived from natural sources has become necessary due to decreasing effectiveness of current antibiotics in treating bacteria that are antibiotic-resistant. In this context, it is well known entomopathogenic (EPBs) produce a broad range secondary metabolites with antibacterial activities. Therefore, an in-vitro trial was conducted isolate and identify non-symbiotic associated nematodes, Steinernema spp. evaluate activity against four antibiotic-resistant bacteria. Four bacterial isolates, i.e. Pseudomonas alcaligenes ST-1, Paenibacillus barcinonensis ST-2, Bacillus mojavensis ST-3, megaterium ST-4 were non-symbiotically isolated heamolymph dead Steinernema-infected Galleria mellonella larvae molecularly characterized. The cells filtrates P. ST-1 strongly inhibited growth Staphylococcus aureus through disk diffusion (43 mm), minimum inhibitory concentration (2.5 µL/mL), minimal bactericidal (5 µL/mL) assay. Conclusively, direct application endogenous Steinernema-associated EPB as agent looked promising.