Abstract
ObjectiveAntibiotic-resistant bacteria are becoming a global crisis, causing death of thousands of people and significant economic impact. The discovery of novel antibiotics is crucial to saving lives and reducing healthcare costs. To address the antibiotic-resistant crisis, in collaboration the Small World Initiative, which aims to crowdsource novel antibiotic discovery, this study aimed to identify antimicrobial producing bacteria and bacterial diversity in the soil of the Stimpson Wildlife Sanctuary, an inland area with a soil salt gradient.ResultsApproximately 4500 bacterial colonies were screened for antimicrobial activity and roughly 100 bacteria were identified as antimicrobial producers, which belong to Entrococcaceae (74%), Yersiniaceae (19%), and unidentified families (7%). Several bacterial isolates showed production of broad spectrum inhibitory compounds, while others were more specific to certain pathogens. The data obtained from the current study provide a resource for further characterization of the soil bacteria with antimicrobial activity, with an aim to discover novel ones. The study showed no correlation between soil salt level and the presence of bacteria with antimicrobial activities. However, most of the identified antimicrobial producing bacteria do not belong to actinomycetes, the most common phyla of antibiotic producing bacteria and this could potentially lead to the discovery of novel antibiotics.
Highlights
While the increasing use of antibiotics in medical and agricultural applications has been beneficial, in recent years overuse of broad-spectrum antibiotics combined with the evolution of bacteria has led to the evolution of deadly antibiotic-resistant bacteria [1,2,3,4]
This bacterial strain was effective in inhibiting the growth of S. newport and B. subtilis
Sample 12B isolated from Cypress Knees and identified as E. faecalis had the lowest inhibition of bacteria (Fig. 1)
Summary
Bacterial isolation Samples from Cypress Knees, which frequently are submerged in water, demonstrated the lowest number of bacterial colonies (1454 CFU/ml). Sample 8A isolated from soil near Cypress Knees and identified as Enterococcus faecalis showed the highest antibiotic production (Fig. 1) This bacterial strain was effective in inhibiting the growth of S. newport and B. subtilis. Sample 12B isolated from Cypress Knees and identified as E. faecalis had the lowest inhibition of bacteria (Fig. 1) This strain was effective in inhibiting B. subtilis only. Among samples of the same nature (Tree Log/Cypress Knees vs soil samples), a number of unique bacterial strains were isolated (Additional file 3: Table S3). The Cypress Knees and the Tree Log have 5 and 6 unique bacterial strains, respectively, while other bacteria were common in other samples The different soil samples showed a number of unique bacterial isolates, with soil near fresh water showing the minimum uniqueness (2 isolates), while soil near 50 PPT water showed the number of unique isolates (5 isolates) (Additional file 3: Table S3)
Sign-in/Register to view highlights & summary Sign-in/Register to access full text options 
Free) 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a call
