Abstract
This study aimed to determine spectrum of antimicrobial activity of crude ethanolic extract (CEE), chloroform (CHCl3) and ethyl acetate (EtOAc) fractions, to determine influence of CHCl3 fraction on Staphylococcus aureus growth and hemolytic activity. Antimicrobial screening of CEE, CHCl3 and EtOAc fractions was carried out using broth microdilution technique against standard strains: Staphyloccocus aureus ATCC25923, Escherichia coli ATCC25922, Pseudomonas aeruginosa ATCC27853 and Candida albicans ATCC76645 to determine the minimum inhibitory concentration (MIC) and minimum bactericidal concentration (MBC). Time kill curves were performed to determine influence of CHCl3 fraction on MIC and ½ MIC concentrations on S. aureus growth. Hemolytic activity of CHCl3 was performed in human erythrocytes to report the cytotoxic effect. CHCl3 fraction showed activity against S. aureus with MIC=1024 µg mL-1 and MBC=2048 µg mL-1. This fraction did not show activity against other tested strains, as well as the CEE and EtOAc fraction. Time kill curve of S. aureus treated with CHCl3 fraction showed that at MIC this fraction has bacteriostatic activity, which was not observed with the ½ MIC. Hemolytic activity demonstrated that when CHCl3 fraction in MIC does not present membrane damage of erythrocytes, since it did not cause hemolysis. Studies should be conducted to evaluate the activity of CHCl3 fraction against S. aureus with different antimicrobial resistance profiles, in addition to evaluating the potential for resistance reversion by in vitro combination studies. The study demonstrated that the species P. montealegreanum can be an important source of compounds of importance for combating microorganisms of clinical importance.
Highlights
Microbial resistance to antimicrobials from community and nosocomial isolates represents a serious public health problem
Antimicrobial screening of crude ethanolic extract (CEE), CHCl3 and EtOAc fractions was carried out using broth microdilution technique against standard strains: Staphyloccocus aureus ATCC25923, Escherichia coli ATCC25922, Pseudomonas aeruginosa ATCC27853 and Candida albicans ATCC76645 to determine the minimum inhibitory concentration (MIC) and minimum bactericidal concentration (MBC)
Minimum inhibitory concentration (MIC) and minimum bactericidal concentration (MBC) was observed that only CHCl3 fraction from P. montealegreanum was able to inhibit the growth of S. aureus American Type Culture Collection (ATCC) 25923 strain
Summary
Microbial resistance to antimicrobials from community and nosocomial isolates represents a serious public health problem. Microorganisms that were previously susceptible to antimicrobial agents, started to show resistance and this selection is mainly due to the indiscriminate use of these drugs (World Health Organization, 2020). The increase in microbial resistance over the years, driven by the indiscriminate use of antibiotics and the emergence of new species of microorganisms not yet reported and with important resistance profiles, resulting on reduction in the clinical treatment options for infections caused by these microorganisms (Roca, et al, 2015), increasing the interest in the search for molecules and new treatment alternatives. The emergence of multi-drug resistant (MDR) microorganisms is cited as a global health problem (Roca, et al, 2015). A recent study showed that there was an increase in the isolation of species of yeast-like fungi such as species of Candida that are resistant to azoles making treatment approaches more difficult (Castanheira, Messer, Rhomberg & Pfaller, 2016)
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
