ABSTRACT

The lack of new therapeutic options to replace many antimicrobial agents that are losing their efficacy against resistant bacteria is a growing concern. The search for new antimicrobials from rare and/or existing sources have thus become a worthwhile effort in recent years. Soil samples collected from Umudike were studied in an effort to screen for novel antibiotics produced by soil microbes. A total of 45 bacterial and 19 fungal isolates were successfully obtained from the soil samples. Antibiotic activity screening using the paper disc diffusion technique was used to evaluate the antagonistic potentials of the isolates against Strains of bacteria including Staphylococcus aureus, Salmonella typhi, Escherichia coli. of the 64 isolates, 6.25% (4/64) were active against at least one of the test organisms with diameter zones of clearing that ranged from 10.0mm to 17.0mm. Isolate Enterobacter species exhibited the strongest antibacterial activity against S. typhi and E. coli with diameter zones of clearing of 17mm and 11.0mm respectively followed by bacillus species which recorded a zone of inhibition of 14mm and 10mm against E. coli and S. aureus respectively. Enterobacter species was tentatively identified as an Enterobacter species based on their colonial morphology and biochemical tests results. Among the isolates which demonstrated antagonism against the test bacteria, bacillus species, Penicillium species, and Enterobacter species were identified as Bacillus spp., Penicillium spp and Enterobacter spp respectively