In Vitro Antifungal Activity of (1)-N-2-Methoxybenzyl-1,10-phenanthrolinium Bromide against Candida albicans and Its Effects on Membrane Integrity

Metal-based drugs, such as 1,10-phenanthroline, have demonstrated anticancer, antifungal and antiplasmodium activities. One of the 1,10-phenanthroline derivatives compounds (1)-N-2-methoxybenzyl-1,10-phenanthrolinium bromide (FEN), which has been demonstrated an inhibitory effect on the growth of Candida spp. This study aimed to explore the in vitro antifungal activity of FEN and its effect on the membrane integrity of Candida albicans. The minimum inhibitory concentration (MIC) and the minimum fungicidal concentration (MFC) of FEN against planktonic C. albicans cells were determined using the broth microdilution method according to the Clinical and Laboratory Standards Institute guidelines. Cell membrane integrity was determined with the propidium iodide assay using a flow cytometer and were visualized using scanning electron microscopy (SEM). Planktonic cells growth of C. albicans were inhibited by FEN, with an MIC of 0.39–1.56 µg/mL and a MFC that ranged from 3.125 to 100 µg/mL. When C. albicans was exposed to FEN, the uptake of propidium iodide was increased, which indicated that membrane disruption is the probable mode of action of this compound. There was cells surface changes of C. albicans when observed under SEM.

Preliminary study of biofilm formation properties and antibiotic susceptibility pattern of MRSA and MSSA isolates obtained in Yogyakarta, Indonesia

Aims: Nowadays, Staphylococcus aureus, especially methicillin resistant Staphylococcus aureus (MRSA), emerged as a major pathogenic agent of nosocomial infection and sepsis worldwide. Infections caused by these bacteria are often difficult to treat because of the development of antibiotic resistance. Biofilm formation is an important factor in the pathogenicity of staphylococcal infections and one of the reason of antibiotic treatment failure. In this study, the relationship between biofilm formation properties, the presence of mecA, icaA/D genes and antimicrobial resistance pattern were investigated in 10 methicillin sensitive Staphylococcus aureus (MSSA) and 10 MRSA clinical isolates. Methodology and results: Staphylococcal strains were identified by conventional microbiological methods, while determination of methicillin susceptibility was distinguished by the presence of mecA gene. To investigate biofilm production, congo red agar and microtiter plate test were performed. PCR was done to detect the presence of icaA/D genes, which responsible for biofilm production. Antibiotic sensitivity was carried out by agar diffusion method. The majority of MRSA isolates (90%) were not able to form biofilm, only one isolate (10%) showed capability of weak biofilm producer. Meanwhile, fully established biofilms were formed by all of MSSA isolates (100%). In addition, all MRSA and almost MSSA isolates (90%) harboured both icaA/D genes in their chromosomes. Antibiotic resistance profile of MRSA was more dominant than MSSA isolates. Conclusion, significance, and impact of study: Biofilm production of staphylococci showed difference regulation with regard to methicillin susceptibility. Antibiotic resistance profile was more dominant in MRSA, however biofilm production was found mostly in MSSA isolates.