Alzhraa Ali Mohamed
Zagazig University,Egypt
Title: Characterization of R-pyocin activity against Gram-positive pathogens for the first time with special focus on Staphylococcus aureus
Biography
Biography: Alzhraa Ali Mohamed
Abstract
Aim: This study is aimed at characterization of both antimicrobial and anti-biofilm activity of R-pyocin from clinical Pseudomonas aeruginosa against Gram-positive pathogens including Staphylococcus aureus. Methods and Results: Pyocinogenic P. aeruginosa was detected using reverse-side method, and pyocinogeny typing was confirmed using revised-spotting method. Transmission electron microscopy (TEM) was used for morphological characterization of R-pyocin and for detection of changes in membrane of R-pyocintreated S. aureus. SDS-PAGE analysis was used for detection of the molecular weight of R-pyocin protein-subunits and Poisson-killing-distribution assay for burstsize calculation. Lipotechoic-acid (LTA) adsorption-assay was used to confirm whether LTA in Gram-positive bacteria served as R-pyocin receptor. Moreover, Rpyocin production at 10–60°C was assessed herein. Host-range of activity of Rpyocin was tested against antimicrobial resistant (AMR) pathogens. The anti-biofilm activity of R-pyocin was detected against sensitive bacterial strains. Chemical, enzymatic, pH and thermo-stability of R-pyocin were evaluated. TEM micrographs revealed a typical morphology of myotailocins indicating the production of R-pyocin designated as RPU15. TEM revealed pores formation in S. aureus membrane, and bacteriophage-like plaques were obvious on plates of R-pyocin-treated S. aureus. Rpyocin activity was neutralized by LTA of S. aureus and Listeria monocytogenes. Pseudomonas aeruginosa PU15 produced ~428 non-inducible R-pyocin particles. RPU15 sheath and tube protein-subunits exhibited a molecular weight of 38 and 23 kDa, respectively. RPU15 possessed activity against S. aureus, L. monocytogenes, Bacillus cereus and Candida albicans and reduced biofilm-biomasses of tested AMR strains.