Discipline: Biological Sciences
Subcategory: Microbiology/Immunology/Virology
Berliza Soriano - Univeristy of Puerto Rico Mayaguez Campus
Co-Author(s): Laura del Valle-Perez and Carlos Rios-Velazquez, Univeristy of Puerto Rico, Mayaguez, PR
Antimicrobials have revolutionized human health care, but in recent years, their effectiveness has been diminishing. Over 70% of bacterial pathogens found in US hospitals are resistant to at least one antibiotic and more than 14,000 patients die annually from resistant nosocomial infections. Being aware of the enormous repercussions of this problem and the scarcity of novel antimicrobials discovered by culture-dependent methods is necessary to implement culture-independent methods such as Metagenomics. For this, an antimicrobial agent production functional analysis methods were performed to four high molecular weight aquatic bodies Metagenomic libraries (AML) generated from samples of Guajataca water reservoir (GWR- G1 and G2), Rio Grande de Añasco (RGA), Playuela Beach (PB). The functional screening was done using two assays: (1) overlay inhibition test and (2) Kirby Bauer assay (KBA). In the first test, 500 clones of the respective AML was spread on Petri plates with Luria Bertani (LB) and after 24 hours of incubation, an overlay of Staphylococcus aureus as the target was done on top of the AML clones. A total of 1% of the clones per AML was screened for antimicrobial agents production. In the KBA, supernatants of the AML, one after centrifuging the un-lysed AML culture (S1) and the other one after lysing the AML culture (S2). After spreading S, aureus on LB plates, 5mm individual disks impregnated with S1 and S2 were placed on top and incubated for 24 hrs. Halos with variable inhibition zones were found in S1 and S2 for the four libraries tested. For PB 57.14% for S1 & 100% for S2 of the disk demonstrated inhibition halos, for G1 57.14% (S1) & 50% (S2) inhibition halos, for G2 the inhibition ratio was 57.14% (S1) & 21.4% (S2) and 78.57% (S1) & 21.4% (S2) inhibition ratio for RGA. These results demonstrated the reliability of Metagenomics in the discovery of antimicrobial products in these environments, representing an opportunity and a new alternative in solving the antibiotic resistant issue.
Funder Acknowledgement(s): Puerto Rico Louis Stokes Alliance for Minority Participation
Faculty Advisor: Carlos Rios-Velazquez, carlos.rios5@upr.edu
Role: This research that I am going to be presenting was completely done by me as part of a major project by Laura del Valle a graduate student in the Microbial Laboratory of Biotechnology and Bioprospects of Carlos Rios Velazquez.