Comparative Evaluation of Medicinal Plant Extracts and Antimicrobial Magistrals.

The in vitro antimicrobial activity of the active ingredient in antimicrobial magistral drug formulations and plant extracts used in folk medicine were investigated comparatively. Borax, sulfur colloid, hydrogen peroxide, benzoic acid, rivanol, brilliant green and plant extracts as active ingredients, namely: Helianthus tuberosus tuber-H2O (aqueous extract), Cydonia oblonga leaves-H2O, Allium porrum whole plant-H2O, Cistus laurifolius leaves-EtOH, Solanum muricalum-H2O, and Fumaria cilicica leaves-EtOH were studied to determine their antimicrobial activity against different bacteria and fungi (S. pyogenes, S. aureus, S. epidermidis, E. faecalis, K. pneumonia, H. influenza, P. aeruginosa, A. baumannii, E. coli, Candida albicans, C. tropicalis, C. parapsilosis, C. krusei) by using the microdilution method. The active ingredients and plant extracts showed different activities as MIC between 1->128 µg/mL. Brilliant green and rivanol as active ingredients had MIC values of 1 µg/mL against all tested microorganisms. C. oblonga leaves-H2O as well as C. laurifolius leaves-EtOH as plant extracts were indicated as having the highest antimicrobial effect in MIC value of 16 µg/ml against A. baumannii and S. pyogenes, respectively. On the other hand, F. cilicica leaves-EtOH and C. laurifolius leaves-EtOH showed the highest antifungal activity (MIC; 16 µg/mL).

Antimicrobial Activity of Ceragenins against Vancomycin-Susceptible and -Resistant Enterococcus spp.

Ceragenins (CSAs) are a new class of antimicrobial agents designed to mimic the activities of endogenous antimicrobial peptides. In this study, the antibacterial activities of various ceragenins (CSA-13, CSA-44, CSA-90, CSA-131, CSA-138, CSA-142, and CSA-192), linezolid, and daptomycin were assessed against 50 non-repeated Enterococcus spp. (17 of them vancomycin-resistant Enterococcus-VRE) isolated from various clinical specimens. Among the ceragenins evaluated, the MIC50 and MIC90 values of CSA-44 and CSA-192 were the lowest (2 and 4 µg/mL, respectively), and further studies were continued with these two ceragenins. Potential interactions between CSA-44 or CSA-192 and linezolid were tested and synergistic interactions were seen with the CSA-192-linezolid combination against three Enterococcus spp., one of them VRE. The effects of CSA-44 and CSA-192 on the MIC values of vancomycin were also investigated, and the largest MIC change was seen in the vancomycin-CSA-192 combination. The in vivo effects of CSA-44 and CSA-192 were evaluated in a Caenorhabditis elegans model system. Compared to no treatment, increased survival was observed with C. elegans when treated with ceragenins. In conclusion, CSA-44 and CSA-192 appear to be good candidates (alone or in combination) for the treatment of enterococcal infections, including those from VRE.

Phenotypic Investigation of Virulence Factors, Susceptibility to Ceragenins, and the Impact of Biofilm Formation on Drug Efficacy in Candida auris Isolates from Türkiye.

Candida auris has emerged as a significant fungal threat due to its rapid worldwide spread since its first appearance, along with its potential for antimicrobial resistance and virulence properties. This study was designed to examine virulence characteristics, the efficacy of ceragenins, and biofilm-derived drug resistance in seven C. auris strains isolated from Turkish intensive care patients. It was observed that none of the tested strains exhibited proteinase or hemolysis activity; however, they demonstrated weak phospholipase and esterase activity. In addition, all strains were identified as having moderate to strong biofilm formation characteristics. Upon determining the minimum inhibitory concentrations (MIC) of ceragenins, it was discovered that CSA-138 exhibited the highest effectiveness with a MIC range of 1-0.5 µg/mL, followed by CSA-131 with a MIC of 1 µg/mL. Also, antimicrobial agents destroyed mature biofilms at high concentrations (40-1280 µg/mL). The investigation revealed that the strains isolated from Türkiye displayed weak exoenzyme activities. Notably, the ceragenins exhibited effectiveness against these strains, suggesting their potential as a viable treatment option.

Antibacterial and Antibiofilm Activities of Ceragenins Alone and in Combination with Levofloxacin Against Multidrug Resistant Myroides spp. Clinical Isolates from Patients with Urinary Tract Infections.

Myroides spp. are rare opportunistic pathogens, but they can be life-threatening because of their multidrug-resistant drug properties and their potential to cause outbreaks, especially in immunosuppressed patients. In this study, 33 isolates isolated from intensive care patients with urinary tract infections were examined for drug susceptibility. All isolates except three proved to be resistant to the tested conventional antibiotics. The effects of ceragenins, a class of compounds developed to mimic endogenous antimicrobial peptides, were evaluated against these organisms. The MIC values of nine ceragenins were determined, and the most effective ceragenins were CSA-131 and CSA-138. Three isolates that were susceptible to levofloxacin and two isolates resistant to all antibiotics underwent 16 s rDNA analysis, and whereas resistant isolates were identified as M. odoratus, susceptible isolates were identified as M. odoratimimus. CSA-131 and CSA-138 showed rapid antimicrobial effects observed in time-kill analyses. Combinations of ceragenins and levofloxacin caused a significant increase in antimicrobial and antibiofilm activities against M. odoratimimus isolates. In this study, Myroides spp. were found to be multidrug-resistant and have biofilm forming capacity, and ceragenins CSA-131 and CSA-138 were found to be especially effective on both planktonic and biofilm forms of Myroides spp.

Effects of Ceragenins and Antimicrobial Peptides on the A549 Cell Line and an In Vitro Co-Culture Model of A549 Cells and Pseudomonas aeruginosa.

Pseudomonas aeruginosa is an important pathogen that can adhere to host tissues and epithelial surfaces, especially during chronic infections such as cystic fibrosis (CF) lung infections. The effect of ceragenins and antimicrobial peptides (AMP) on this colonization was investigated in a co-culture infection model. After determining the antimicrobial effects of the substances on P. aeruginosa planktonic cells, their cytotoxicity on the A549 cell line was also determined. After the A549 cell line was infected with P. aeruginosa, the effect of antimicrobials on intracellular bacteria as well as the effects in inhibiting the adhesion of P. aeruginosa were investigated. In addition, LDH release from cells was determined by performing an LDH experiment to understand the cytotoxicity of bacterial infection and antimicrobial treatment on cells. CSA-131 was determined as the antimicrobial agent with the highest antimicrobial activity, while the antimicrobial effects of AMPs were found to be much lower than those of ceragenins. The antimicrobial with the lowest IC50 value was determined as the combination of CSA-131 with Pluronic F127. CSA-13 has been determined to be the most effective antimicrobial with its effectiveness to both intracellular bacteria and bacterial adhesion. Nevertheless, further safety, efficacy, toxicity, and pharmacological studies of ceragenins are needed to evaluate clinical utility.

Comparative Fungicidal Activities of N-Chlorotaurine and Conventional Antiseptics against Candida spp. Isolated from Vulvovaginal Candidiasis.

N-chlorotaurine (NCT), the N-chloro derivative of the amino acid taurine, is a long-lived oxidant produced by stimulated human leucocytes. NCT has antimicrobial activities which are generally enhanced in the presence of organic material. The aim of this study was to investigate fungicidal effects of NCT and conventional antiseptics against Candida isolated from vulvovaginal candidiasis (VVC). Chlorhexidine (CHX, 1.6%), octenidine dihydrochloride (OCT, 0.08%), povidone iodine (PVP-I, 8%), boric acid (8%), and NCT (0.1% (5.5 mM)) were evaluated against forty-four Candida isolates, according to European Standard methods, at 30, 60, 90, and 120 min and 24 h in the presence of skim milk as an organic material. CHX, OCT, and PVP-I showed rapid fungicidal activity against all Candida isolates with 5-6 log10 reduction of viable counts after 30 min, whereas boric acid and NCT needed 1 h against Candida albicans and 2 h against non-albicans Candida for a significant 3 log10 reduction. NCT showed fungicidal activity (defined as ≥4 log10 reduction) against C. albicans within 90 min and C. non-albicans within 24 h. Based upon all presently available data, including our results, NCT could be used as a new agent for treatment of local fungal infections such as VVC.

In vitro activity of ceragenins against Burkholderia cepacia complex.

Burkholderia cepacia complex (Bcc) species are aerobic, Gram-negative and non-fermantative bacilli. Bcc can cause clinical symptoms in patients with cystic fibrosis, ranging from asymptomatic carriage to fatal pneumonia. A pressing need exists for new antimicrobial agents that target Bcc. Ceragenins, CSA-13, CSA-131 and CSA-131 with 5% Pluronic® F127 (CSA-131P), were evaluated against Bcc clinical isolates (n = 42). MICs of ceragenins and conventional antibiotics were determined. Time-kill curve experiments were performed with 1x, 4x MICs of ceragenins and sulfamethoxazole-trimethoprim (SXT), levofloxacin. MIC50/ MIC90 results (mg l-1) of CSA-13, CSA-131 and CSA-131P were determined as 16/64, 16/128 and 16/128, respectively. CSA-13 and CSA-131 showed bactericidal activity. CSA-13 - levofloxacin combination displayed synergistic activity against Bcc. First-generation (CSA-13) and second-generation (CSA-131 and CSA-131P) ceragenins have significant antimicrobial effects on Bcc. The findings of this study demonstrate that combinations of ceragenins with currently marketed antibiotics could be synergistic in vitro against Bcc isolates. These results suggest that combination therapy with conventional antibiotics could be an alternative approach for treating Bcc infections in the future.

Oregano essential oil inhibits Candida spp. biofilms.

Candida spp. can form biofilms on mucosal surfaces and epithelial cells as well as on devices implanted in the body such as catheters and dentures, which are thought to underlie the most recalcitrant infections. It was aimed to show antifungal and antibiofilm activities of oregano oil (Origanum onites). The antifungal activities of some essential oils were investigated against C. spp. and among them, oregano oil was found to be the most effective oil and further biofilm studies were conducted with it. Oregano oil inhibited biofilm adhesion and formation of C. spp. and mature biofilms and also displayed the ability to reduce biofilm formation when they were allowed to form on surfaces previously coated with oil (up to 50% inhibition rates). In addition, oregano oil was found to be effective against dual biofilms of Candida albicans + Staphyloccocus aureus at different concentrations. This study suggests that O. onites essential oil has useful antibiofilm effects against C. spp. The inhibitory effects of O. onites essential oil, against C. spp., were demonstrated for the first time. It also had antifungal effect on biofilm formation and established biofilm even at MIC level.

In vitro assessment of CSA-131 and CSA-131 poloxamer form for the treatment of Stenotrophomonas maltophilia infections in cystic fibrosis.

BACKGROUND: Stenotrophomonas maltophilia is a Gram-negative bacterium resistant to several antibiotics and its prevalence in cystic fibrosis (CF) patients is increasing. OBJECTIVES: To evaluate the effects of ceragenins, non-peptide mimics of antimicrobial peptides, against both planktonic and biofilm forms of S. maltophilia and the cytotoxicity of ceragenins to the IB3-1 CF cell line. METHODS: Ceragenin CSA-131, with and without 5% Pluronic® F127 (a non-ionic amphiphilic poloxamer), and ceragenin CSA-13 were evaluated against S. maltophilia clinical isolates (n = 40). MICs and MBCs of ceragenins and conventional antibiotics were determined. Time-kill curve experiments were performed with 1×, 2× and 4× MICs of ceragenins. The highest non-cytotoxic concentrations of ceragenins against IB3-1, a CF cell line, were determined by MTT assay. The effects of ceragenins against biofilm adhesion, formation and mature biofilms were investigated. RESULTS: CSA-131 with Pluronic® F127 displayed the lowest MICs (MIC50/MIC90: 1/2 mg/L) followed by CSA-131 (MIC50/MIC90: 2/4 mg/L), while those of CSA-13 were much higher (MIC50/MIC90: 16/32 mg/L). According to time-kill curve results, all concentrations at 4× MICs of ceragenins showed bactericidal activity (3 log reduction) after 4 h. While CSA-131 and CSA-131-poloxamer inhibited biofilm adhesion and formation by 87.74% and 83.42%, respectively, after 24 h, CSA-131 was more effective on mature biofilms. Formulating CSA-131 in poloxamer micelles did not affect the cytotoxicity of CSA-131 to IB3-1 cells. CONCLUSIONS: CSA-131 could be a potential antimicrobial agent for the treatment of S. maltophilia infections in CF, due to its low cytotoxicity on the CF cell line and good antimicrobial and antibiofilm effects.

Biofilm modelling on the contact lenses and comparison of the in vitro activities of multipurpose lens solutions and antibiotics.

During the contact lens (CL) usage, microbial adhesion and biofilm formation are crucial threats for eye health due to the development of mature biofilms on CL surfaces associated with serious eye infections such as keratitis. For CL related eye infections, multi drug resistant Pseudomonas aeruginosa or Staphylococcus aureus (especially MRSA) and Candida albicans are the most common infectious bacteria and yeast, respectively. In this study, CL biofilm models were created by comparing them to reveal the differences on specific conditions. Then the anti-biofilm activities of some commercially available multipurpose CL solutions (MPSs) and antibiotic eye drops against mature biofilms of S. aureus, P. aeruginosa, and C. albicans standard and clinical strains were determined by the time killing curve (TKC) method at 6, 24 and 48 h. According to the biofilm formation models, the optimal biofilms occurred in a mixture of bovine serum albumin (20% v/v) and lysozyme (2 g/L) diluted in PBS at 37 °C for 24 h, without shaking. When we compared the CL types under the same conditions, the strongest biofilms according to their cell density, were formed on Pure Vision ≥ Softens 38 > Acuve 2 âˆ¼ Softens Toric CLs. When we compared the used CLs with the new ones, a significant increase at the density of biofilms on the used CLs was observed. The most active MPS against P. aeruginosa and S. aureus biofilms at 24 h was Opti-Free followed by Bio-True and Renu according to the TKC analyses. In addition, the most active MPS against C. albicans was Renu followed by Opti-Free and Bio-True at 48 h. None of the MPSs showed 3 Log bactericidal/fungicidal activity, except for Opti-Free against S. aureus and P. aeruginosa biofilms during 6 h contact time. Moreover, all studied antibiotic eye drops were active against S. aureus and P. aeruginosa biofilms on CLs at 6 h and 24 h either directly or as 1/10 concentration, respectively. According to the results of the study, anti-biofilm activities of MPSs have changed depending on the chemical ingredients and contact times of MPSs, the type of infectious agent, and especially the CL type and usage time.

Synergistic Activity of Ceragenins Against Carbapenem-Resistant Acinetobacter baumannii Strains in Both Checkerboard and Dynamic Time-Kill Assays.

Acinetobacter baumannii is an emerging opportunistic pathogen that primarily infects critically ill patients in nosocomial settings and there is a need for identifying new alternative therapeutic agents against these organisms. Ceragenins are non-peptide, membrane-active agents that mimic the antimicrobial properties of antimicrobial peptides (AMPs) and affect the membrane permeability of microorganisms. The in vitro activities of CSA-8, CSA-13, CSA-44, CSA-131, CSA-138 either alone or in combination with colistin (sulphate) were determined against 25 carbapenem-resistant A. baumannii strains. Minimum inhibitory concentrations (MICs) and minimum bactericidal concentrations (MBCs) of selected ceragenins and colistin against these isolates were measured by in vitro microbroth dilution techniques. Checkerboard techniques and time-kill assays were performed to determine the activities of combinations. The MIC50 values (mg/L) of CSA-8, CSA-13, CSA-44, CSA-131, CSA-138 and colistin were 32, 4, 8, 2, 4 and 0.5, respectively. The MIC90 (mg/L) of CSA-8, CSA-13, CSA-44, CSA-131, CSA-138 and colistin were 128, 8, 16, 8, 16 and 16, respectively. At 6 h, 1×MIC and 2×MIC of CSA-13 were bactericidal. CSA-13 + colistin combination displayed synergistic interaction. Antagonism between antimicrobials was not observed. According to the results, CSA-13 and CSA-131 can be good alternatives for infections caused by carbapenem-resistant A. baumannii.

Antibiofilm activities of ceragenins and antimicrobial peptides against fungal-bacterial mono and multispecies biofilms.

Multispecies biofilms, in which both fungus and bacteria species can be present, play a significant role in persistent infections, and new therapeutic options are needed against them. In this study, the activities of ceragenins and antimicrobial peptides (AMPs) (magainin, cecropin A, LL-37) were investigated against multispecies biofilms formed by Candida albicans and four clinically important Gram-negative bacteria, including Pseudomonas aeruginosa, Acinetobacter baumannii, Escherichia coli, and Klebsiella pneumoniae. Our results show that CSA-13 and CSA-90 were the most effective agents against both mono and multispecies biofilms (P < 0.05). CSA-131 and CSA-192 showed the least antimicrobial activity against mono and fungal-bacterial multispecies biofilms. Inhibition of multispecies biofilms with CSA-13 and CSA-90 was also confirmed through fluorescence microscopy images. When AMPs evaluated alone, they proved ineffective against both C. albicans and Gram-negative bacteria at the concentrations tested. In these studies, ceragenins were much more effective than AMPs against multi or monospecies biofilms, especially those containing C. albicans.

A comparative evaluation of Juniperus species with antimicrobial magistrals.

The objective of this study was to evaluate the in vitro bioactivity of the active ingredient in selected antimicrobial magistral drug formulations and plant extracts used in folk medicine, comparatively. The active ingredients of magistrals such as; boric acid, balsam of Peru, zinc oxide, Calendula tincture, thymol, resorcinol, crystal violet were used as well as fruit or leaf extracts of Juniperus excelsa (Je), J. sabina (Js), J. foetidissima (Jf), J. communis ssp. nana (Jcsn), and J. oxycedrus spp. oxycedrus ripe (Joso) to determine the antimicrobial activity against gram positive bacteria (S. pyogenes, S. aureus, S. epidermidis, E. faecalis), gram negative bacteria (K. pneumoniae, H. influenza, P. aeruginosa, A. baumannii, E. coli), and fungi (Candida. albicans, C. tropicalis, C. parapsilosis, C. krusei) by using microdilution method. The inhibition end point of the minimum inhibition concentrations (MICs) were determined as µ mL-1. The active ingredient and plant extracts have shown antibacterial and antifungal activities with a MIC values of 1->128µmL-1. The active ingredient crystal violet (MIC; 1 µ mL-1) as well as Je- fruit ethanol, Jf-leaf and fruit ethanol, Joso-leaf and fruit ethanol extracts (MIC; 16µ mL-1) have exhibited the highest antimicrobial activities (MIC; 16µ mL-1). Although ingredients of magistrals seem to exert similar antifungal activity against C. albicans, C. tropicalis, and C. parapsilosis (MIC; 32µmL-1), thymol and resorcinol were observed to be more active against C. krusei (MIC; 16µ mL-1). Extracts were more pronounced against P. aeruginosa, A. baumannii, and S. epidermidis (MIC ranging from 16 to 32). In the mine time, the extracts showed equal antifungal activity against C. albicans and C. parapsilosis (MIC; 16µ mL-1). In our study, antimicrobial activity of the natural compounds and ingredients of selected magistrals have found to be promising with MIC values of 16-32µ mL-1. According to the results of our antimicrobial activity studies, utilization of Juniperus extracts in antimicrobial magistral formulations can be suggested.

Immunization against poly-N-acetylglucosamine reduces neutrophil activation and GVHD while sparing microbial diversity.

Microbial invasion into the intestinal mucosa after allogeneic hematopoietic cell transplantation (allo-HCT) triggers neutrophil activation and requires antibiotic interventions to prevent sepsis. However, antibiotics lead to a loss of microbiota diversity, which is connected to a higher incidence of acute graft-versus-host disease (aGVHD). Antimicrobial therapies that eliminate invading bacteria and reduce neutrophil-mediated damage without reducing the diversity of the microbiota are therefore highly desirable. A potential solution would be the use of antimicrobial antibodies that target invading pathogens, ultimately leading to their elimination by innate immune cells. In a mouse model of aGVHD, we investigated the potency of active and passive immunization against the conserved microbial surface polysaccharide poly-N-acetylglucosamine (PNAG) that is expressed on numerous pathogens. Treatment with monoclonal or polyclonal antibodies to PNAG (anti-PNAG) or vaccination against PNAG reduced aGVHD-related mortality. Anti-PNAG treatment did not change the intestinal microbial diversity as determined by 16S ribosomal DNA sequencing. Anti-PNAG treatment reduced myeloperoxidase activation and proliferation of neutrophil granulocytes (neutrophils) in the ileum of mice developing GVHD. In vitro, anti-PNAG treatment showed high antimicrobial activity. The functional role of neutrophils was confirmed by using neutrophil-deficient LysMcreMcl1fl/fl mice that had no survival advantage under anti-PNAG treatment. In summary, the control of invading bacteria by anti-PNAG treatment could be a novel approach to reduce the uncontrolled neutrophil activation that promotes early GVHD and opens a new avenue to interfere with aGVHD without affecting commensal intestinal microbial diversity.

Comparative in vitro antimicrobial activities of CSA-142 and CSA-192, second-generation ceragenins, with CSA-13 against various microorganisms.

Ceragenins, a novel family of antibiotics, are cationic derivatives of cholic acid and display broad-spectrum antimicrobial activities. Multiple ceragenins have been synthesized and studied, and most published data are with ceragenin CSA-13. This study aimed to investigate the in vitro antimicrobial properties of second-generation ceragenins, CSA-142 and CSA-192, and compare them to CSA-13. The antimicrobial activities of CSA-13, CSA-142 and CSA-192 were studied against 20 strains of Escherichia coli, Acinetobacter baumannii, Pseudomonas aeruginosa, Staphylococcus aureus and Candida albicans. Time-kill curve methods were performed to determine the bactericidal and fungicidal activities of the ceragenins against three strains of each microorganism. Overall, CSA-13 showed the lowest MIC values, but also CSA-142 and CSA-192 had good activities against tested microorganisms. The killing curves showed that ceragenins generally had bactericidal and fungicidal effects. The bactericidal and fungicidal behaviours of CSA-142 and CSA-192 may make them good alternative agents to CSA-13.

Antimicrobial effect of the extracts from Hypericum perforatum against oral bacteria and biofilm formation.

CONTEXT: One traditional medicines, Hypericum perforatum L. (Hypericaceae), possesses several beneficial effects against depression, ulcers, dyspepsia, abdominal pains, burns, bacterial infections, migraine headaches, and sciatica. OBJECTIVE: The present study investigates the antimicrobial activity of the ethanol extract (HP-EtOH) of H. perforatum and its sub-extracts, namely n-hexane (HP-hexane), chloroform (HP-CHCl3), ethyl acetate (HP-EtOAc), n-butanol (HP-n-BuOH), and water (HP-H2O) extracts, against Streptococcus mutans, S. sobrinus, Lactobacillus plantarum, and Enterococcus faecalis. MATERIALS AND METHODS: For the evaluation of the antimicrobial activity, flowering aerial parts of H. perforatum were extracted with EtOH and then this extract was fractionated to obtain five sub-extracts in different polarities. Antimicrobial activities of HP-EtOH and its sub-extracts against Streptococcus mutans, S. sobrinus, L. plantarum, and E. faecalis were assessed by using colorimetric micro-well dilution at concentration ranges of 64-0.5 µg/ml as well as resazurin microplate and modified microtiter-plate assays between the ranges of 100 and 0.78125 µg/ml. RESULTS: According to the results of the present study, HP-H2O sub-extract displayed strong antibacterial activity (MIC values 8 µg/mL) against S. sobrinus and L. plantarum, and exerted moderate activity against S. mutans and E. faecalis at 32 and 16 µg/mL concentrations, respectively. Other sub-extracts also demonstrated antimicrobial activity against S. sobrinus at a concentration of 16 µg/mL. HP-EtOAc and HP-n-BuOH showed antimicrobial activity against L. plantarum and HP-EtOAc and HP-H2O were also active against E. faecalis at the same concentrations (16 µg/mL). CONCLUSION: According to the results, we suggest that H. perforatum could be employed as a natural antibacterial agent in oral care products.