Microbiology
Forough Goodarzi; Masoumeh Hallajzadeh; Mohammad Sholeh; Malihe Talebi; Vahid Pirhajati Mahabadi; Nour Amirmozafari
Abstract
Background & Objective: This study aims to isolate a lytic bacteriophage against planktonic Enterococcus faecalis V583 culture and evaluate its ability to disrupt and inhibit biofilm.Methods: An anti-E. faecalis phage was isolated from sewage and visualized by electron microscopy, the vB_EfsS_V583 ...
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Background & Objective: This study aims to isolate a lytic bacteriophage against planktonic Enterococcus faecalis V583 culture and evaluate its ability to disrupt and inhibit biofilm.Methods: An anti-E. faecalis phage was isolated from sewage and visualized by electron microscopy, the vB_EfsS_V583 (V583) host range was determined by spot test on 13 E. faecalis clinical strains. Inhibition and degradation experiments were designed to investigate the effect of phage on biofilm. In the inhibition and degradation assay, biofilms were formed in the presence and absence of phage, respectively. Finally, crystal violet method tested the effect of phage on biofilm.Results: Phage V583 belongs to the Siphoviridae family and can infect all E. faecalis strains. Antibacterial activity has been shown to degrade and inhibit biofilm produced by V583. The study results showed that phage v583 is more efficient in biofilm inhibition than biofilm degradation. In both assays, phage-treated wells' absorption is less than untreated wells. These results were confirmed by Colony-forming unit reduction in the treated biofilm.Conclusion: The anti-biofilm activity showed that phage therapy using phage V583 might be an alternative tool to remove E. faecalis biofilms.
Microbiology
Sara Masoumi Zavaryani; Reza Mirnejad; Vahhab Piranfar; Mehrdad Moosazadeh Moghaddam; Nikta Sajjadi; Somayyeh Saeedi
Abstract
Background & Objective: Enterococcus Species are the common cause of nosocomial infections, which are highly resistant to different antibiotics. Therefore, determination of their antibiotic susceptibility patterns and simultaneous resistance to antibiotics is important for better treatment strategies. ...
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Background & Objective: Enterococcus Species are the common cause of nosocomial infections, which are highly resistant to different antibiotics. Therefore, determination of their antibiotic susceptibility patterns and simultaneous resistance to antibiotics is important for better treatment strategies. Methods: 400 clinical Enterococcus isolates were collected from different hospitals in Tehran, Iran. Standard phenotypic-biochemical tests and PCR were used to identify the Enterococcus species. The antimicrobial susceptibility patterns and simultaneous resistance to selected antibiotics were determined by disk diffusion method according to the CLSI guidelines. All data analysis was performed using Python packages Scipy and Stats models. Result: According to the biochemical and PCR analyses, among 400 Enterococcus species, 72% of samples were Enterococcus faecalis, 10.75% Enterococcus faecium, and 17.25% other Enterococcus species. The results determined antimicrobial resistances of these strains against gentamicin, vancomycin, fosfomycin trometamol, teicoplanin, and quinupristin/dalfopristin. Results confirmed a significant correlation between resistance to vancomycin and resistance to teicoplanin. This correlation remains significant when including only E. faecium or E. faecalis species. We also found a negative correlation between resistance to teicoplanin and quinupristin/dalfopristin. Additionally, Quinupristin/dalfopristin was the least effective antibiotic while vancomycin and teicoplanin were the most effective ones. Conclusion: Based on the results and association between simultaneous resistance to some antibiotics such as vancomycin and teicoplanin, in the case of antibiotic resistance, the choice of a second antibiotic can be very important which can lead to good or bad effects.