Antimicrobial Activities of Ceragenins against Clinical Isolates of Resistant Staphylococcus aureus

ABSTRACT The rise in the rates of glycopeptide resistance among Staphylococcus aureus isolates is concerning and underscores the need for the development of novel potent compounds. Ceragenins CSA-8 and CSA-13, cationic steroid molecules that mimic endogenous antimicrobial peptides, have previously been demonstrated to possess broad-spectrum activities against multidrug-resistant bacteria. We examined the activities of CSA-8 and CSA-13 against clinical isolates of vancomycin-intermediate S. aureus (VISA), heterogeneous vancomycin-intermediate S. aureus (hVISA), as well as vancomycin-resistant S. aureus (VRSA) and compared them to those of daptomycin, linezolid, and vancomycin by susceptibility testing and killing curve analysis. We also examined CSA-13 for its concentration-dependent activity, inoculum effect, postantibiotic effect (PAE), and synergy in combination with various antimicrobials. Overall, the MICs and minimal bactericidal concentrations of CSA-13 were fourfold lower than those of CSA-8. Time-kill curve analysis of the VRSA, VISA, and hVISA clinical isolates demonstrated concentration-dependent bactericidal killing. An inoculum effect was also observed when a higher starting bacterial density was used, with the time required to achieve 99.9% killing reaching 1 h with a 6-log10-CFU/ml starting inoculum, whereas it was ≥24 h with a 8- to 9-log10-CFU/ml starting inoculum with 10× the MIC (P ≤ 0.001). A concentration-dependent PAE was demonstrated with CSA-13, nearly doubling from 2× to 4× the MIC (P = 0.03). With respect to the CSA-13 antimicrobial combinations, time-kill curve analysis showed no difference in the log10 CFU/ml at 24 h for the majority of the organisms tested. However, early synergy at 4 to 8 h was detected against the VRSA Pennsylvania strain (2002) when CSA-13 was tested in combination with gentamicin, while early additivity was demonstrated against all of the other organisms.

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Comparative In Vitro Activities of First and Second-Generation Ceragenins Alone and in Combination with Antibiotics Against Multidrug-Resistant Klebsiella pneumoniae Strains

Antibiotics ◽

10.3390/antibiotics8030130 ◽

2019 ◽

Vol 8 (3) ◽

pp. 130 ◽

Cited By ~ 5

Author(s):

Berna Ozbek-Celik ◽

Damla Damar-Celik ◽

Emel Mataraci-Kara ◽

Cagla Bozkurt-Guzel ◽

Paul B. Savage

Keyword(s):

Klebsiella Pneumoniae ◽

Second Generation ◽

Synergistic Effects ◽

Multidrug Resistant ◽

Antimicrobial Activities ◽

Resistant Bacteria ◽

Microdilution Method ◽

Kill Curve ◽

Time Kill

Objectives: The ceragenins, or CSAs, were designed to mimic the activities of antimicrobial peptides and represent a new class of antimicrobial agent. The aim of this study was to comparatively investigate the antimicrobial activities of first/second generation ceragenins and various antibiotics against multidrug-resistant (MDR) Klebsiella pneumoniae, including colistin-resistant bacteria. Also, the synergistic effects of two ceragenins with colistin or meropenem were investigated with six K. pneumoniae strains presenting different resistant patterns. Methods: Minimal inhibition concentrations (MICs) were determined by the microdilution method according to the CLSI. Antibiotic combination studies were evaluated by the time–kill curve method. Results: MIC50 and MIC90 values of tested ceragenins ranged from 8 to 32 mg/L and 16 to 128 mg/L. Overall, among the ceragenins tested, CSA-131 showed the lowest MIC50 and MIC90 values against all microorganisms. The MICs of the ceragenins were similar or better than tested antibiotics, except for colistin. Synergistic activities of CSA-131 in combination with colistin was found for strains both at 1× MIC and 4× MIC. No antagonism was observed with any combination. Conclusions: First-generation ceragenins CSA-13 and CSA-44 and second-generation ceragenins CSA-131, CSA-138 and CSA-142 have significant antimicrobial effects on MDR K. pneumoniae. Mechanisms allowing resistance to clinical comparator antibiotics like colistin did not impact the activity of ceragenins. These results suggest that ceragenins may play a role in treating infections that are resistant to known antibiotics.

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Antimicrobial activities of widely consumed herbal tea’s alone or in combination with antibiotics: An in vitro study

10.7287/peerj.preprints.2029v1 ◽

2016 ◽

Author(s):

Mayram Tuysuz ◽

Sibel Dosler ◽

Ayse Seher Birteksoz Tan ◽

Gulten Otuk

Keyword(s):

Escherichia Coli ◽

Staphylococcus Aureus ◽

In Vitro Study ◽

Antimicrobial Activities ◽

Combination Studies ◽

Kill Curve ◽

Time Kill ◽

Microbroth Dilution ◽

Antagonistic Interactions

Background: Because of increasing antibiotic resistance, herbal teas are the most popular natural alternatives, which are gaining even more importance. We examined the antimicrobial activities of 31 herbal teas both alone and in combination with antibiotics or antifungals against the standard and clinical isolates of Pseudomonas aeruginosa, Acinetobacter baumannii, Escherichia coli, Klebsiella pneumoniae, Enterococcus faecalis, methicillin susceptible/resistant Staphylococcus aureus and Candida albicans. Methods: The antimicrobial activities of the teas were determined by using the disk diffusion and microbroth dilution methods, and the combination studies were examined by using the microbroth checkerboard and time killing curve methods. Results: Rosehip, rosehip bag, pomegranate blossom, thyme, wormwood, mint, echinacea bag, cinnamon, black, and green teas were active against most of the studied microorganisms. In the combination studies, we characterized all the expected effects (synergistic, additive, and antagonistic) between the teas and the antimicrobials. While synergy was observed more frequently between ampicillin, ampicillin-sulbactam, or nystatine, and the various tea combinations, most of the effects between the ciprofloxacin, erythromycin, cefuroxime, or amikacin and various tea combinations, particularly rosehip, rosehip bag, and pomegranate blossom teas, were antagonistic. The results of the time kill curve analyses showed that none of the herbal teas were bactericidal in their usage concentrations; however, in combination they were. Discussion: Some herbal teas, particularly rosehip and pomegranate blossom should be avoided because of antagonistic interactions during the course of antibiotic treatment or should be consumed alone.

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Antimicrobial Activities of Laurus nobilis Leaves Ethanol Extract on Staphylococcus aureus, Salmonellae typhi, and Escherichia coli.

Indonesian Journal of Tropical and Infectious Disease ◽

10.20473/ijtid.v9i2.22873 ◽

2021 ◽

Vol 9 (2) ◽

pp. 119

Author(s):

Khawla Abdullah Sakran ◽

Dadik Raharjo ◽

Ni Made Mertaniasih

Keyword(s):

Escherichia Coli ◽

Staphylococcus Aureus ◽

Minimum Bactericidal Concentration ◽

Ethanol Extract ◽

Multidrug Resistant ◽

Antimicrobial Activities ◽

Resistant Bacteria ◽

Zone Of Inhibition ◽

Laurus Nobilis

Laurus nobilis is one of the most well-known, most frequently used plants is from Lauraceae family which contains up 2.500 species that grow in the subtropics and tropics of the Mediterranean region and Indonesia. This study was supposed to investigate the antimicrobial eﬀ ect of L.nobilis leaves ethanol extract on Staphylococcus aureus, Salmonellae typhi, and Escherichia coli. This preliminary study examined the antimicrobial eﬀ ect of L.nobilis leaves ethanol extract. The method used Agar-well diﬀ usion for determination of the zone of inhibition and the minimum bactericidal concentration to investigate the activity of L.nobilis leaves ethanol extract at 100% concentration . The results revealed that extract of L. nobilis leaves had the antibacterial activity against Staphylococcus aureus with a zone of inhibition (16.3 ±1.5 mm), Staphylococcus aureus with (14.5±0.5 mm), and weak antimicrobial activity against Escherichia coli (11.3±1.1mm). Also, through the minimum bactericidal concentration experiment, the L.nobilis leaves ethanol extract had activity on Staphylococcus aureus and Salmonellae typhi, it’s killed the bacteria in all concentration start it from 5×107 to 5×104. But the activity on Escherichia coli just weaken concentration 5×107 and 106. This research has concluded that the L.nobilis leaves ethanol extract exhibited a signiﬁ cant antimicrobial eﬀ ect against Staphylococcus aureus and Salmonellae typhi then Escherichia coli that is considered a kind of multidrug-resistant bacteria.

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Antimicrobial activities of widely consumed herbal tea’s alone or in combination with antibiotics: An in vitro study

10.7287/peerj.preprints.2029 ◽

2016 ◽

Author(s):

Mayram Tuysuz ◽

Sibel Dosler ◽

Ayse Seher Birteksoz Tan ◽

Gulten Otuk

Keyword(s):

Escherichia Coli ◽

Staphylococcus Aureus ◽

In Vitro Study ◽

Antimicrobial Activities ◽

Combination Studies ◽

Kill Curve ◽

Time Kill ◽

Microbroth Dilution ◽

Antagonistic Interactions

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Antimicrobial activities of widely consumed herbal teas, alone or in combination with antibiotics: anin vitrostudy

PeerJ ◽

10.7717/peerj.3467 ◽

2017 ◽

Vol 5 ◽

pp. e3467 ◽

Cited By ~ 10

Author(s):

Mayram Hacioglu ◽

Sibel Dosler ◽

Ayse Seher Birteksoz Tan ◽

Gulten Otuk

Keyword(s):

Escherichia Coli ◽

Staphylococcus Aureus ◽

Pseudomonas Aeruginosa ◽

Bactericidal Effect ◽

Antimicrobial Activities ◽

Combination Studies ◽

Kill Curve ◽

Time Kill ◽

Microbroth Dilution ◽

Antagonistic Interactions

BackgroundBecause of increasing antibiotic resistance, herbal teas are the most popular natural alternatives for the treatment of infectious diseases, and are currently gaining more importance. We examined the antimicrobial activities of 31 herbal teas both alone and in combination with antibiotics or antifungals against some standard and clinical isolates ofPseudomonas aeruginosa,Acinetobacter baumannii,Escherichia coli,Klebsiella pneumoniae,Enterococcus faecalis, methicillin susceptible/resistantStaphylococcus aureusandCandida albicans.MethodsThe antimicrobial activities of the teas were determined by using the disk diffusion and microbroth dilution methods, and the combination studies were examined by using the microbroth checkerboard and the time killing curve methods.ResultsRosehip, rosehip bag, pomegranate blossom, thyme, wormwood, mint, echinacea bag, cinnamon, black, and green teas were active against most of the studied microorganisms. In the combination studies, we characterized all the expected effects (synergistic, additive, and antagonistic) between the teas and the antimicrobials. While synergy was observed more frequently between ampicillin, ampicillin-sulbactam, or nystatine, and the various tea combinations, most of the effects between the ciprofloxacin, erythromycin, cefuroxime, or amikacin and various tea combinations, particularly rosehip, rosehip bag, and pomegranate blossom teas, were antagonistic. The results of the time kill curve analyses showed that none of the herbal teas were bactericidal in their usage concentrations; however, in combination with antibiotics they showed some bactericidal effect.DiscussionSome herbal teas, particularly rosehip and pomegranate blossom should be avoided because of their antagonistic interactions with some antibiotics during the course of antibiotic treatment or they should be consumed alone for their antimicrobial activities.

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Combination Therapy of Sophoraflavanone B against MRSA:In VitroSynergy Testing

Evidence-based Complementary and Alternative Medicine ◽

10.1155/2013/823794 ◽

2013 ◽

Vol 2013 ◽

pp. 1-7 ◽

Cited By ~ 8

Author(s):

Su-Hyun Mun ◽

Ok-Hwa Kang ◽

Dae-Ki Joung ◽

Sung-Bae Kim ◽

Yun-Soo Seo ◽

...

Keyword(s):

Staphylococcus Aureus ◽

Antimicrobial Activity ◽

Antibacterial Activity ◽

Multidrug Resistant ◽

Antibacterial Drug ◽

Broth Microdilution ◽

Microdilution Method ◽

Broth Microdilution Method ◽

Kill Curve ◽

Time Kill

Sophoraflavanone B (SPF-B), a known prenylated flavonoid, was isolated from the roots ofDesmodium caudatum. The aim of this study was to determine the antimicrobial synergism of SPF-B combined with antibiotics against methicillin-resistantStaphylococcus aureus(MRSA). MRSA, a multidrug-resistant pathogen, causes both hospital- and community-acquired infections worldwide. The antimicrobial activity of SPF-B was assessed by the broth microdilution method, checkerboard dilution test, and time-kill curve assay. The MIC of SPF-B for 7 strains ofS. aureusranges from 15.6 to 31.25 μg/mL determined. In the checkerboard method, the combinations of SPF-B with antibiotics had a synergistic effect; SPF-B markedly reduced the MICs of theβ-lactam antibiotics: ampicillin (AMP) and oxacillin (OXI); aminoglycosides gentamicin (GET); quinolones ciprofloxacin (CIP) and norfloxacin (NOR) against MRSA. The time-kill curves assay showed that a combined SPF-B and selected antibiotics treatment reduced the bacterial counts below the lowest detectable limit after 24 h. These data suggest that the antibacterial activity of SPF-B against MRSA can be effectively increased through its combination with three groups of antibiotics (β-lactams, aminoglycosides, and quinolones). Our research can be a valuable and significant source for the development of a new antibacterial drug with low MRSA resistance.

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Antibacterial Effect of Persicaria thunbergii on Staphylococcus aureus

Journal of Medicinal Herbs and Ethnomedicine ◽

10.25081/jmhe.2018.v4.3501 ◽

1970 ◽

pp. 31-34

Author(s):

Maheshkumar Prakash Patil ◽

Eun-Soo Noh ◽

Yeong-Ae Seong, Gun-Do Kim

Keyword(s):

Staphylococcus Aureus ◽

Ethyl Acetate ◽

Antibacterial Effect ◽

Natural Compounds ◽

Antimicrobial Activities ◽

Diffusion Method ◽

Resistant Bacteria ◽

Disk Diffusion Method ◽

Antibiotic Resistant ◽

Time Kill

With the discovery of various antibiotic resistant bacteria, evaluations of antimicrobial activities of natural compounds have been preceded on antibiotic susceptible and resistant microorganisms. Several types of natural compounds have been reported to have similar effects on target microorganisms as compared to the widely used antibiotics. Persicaria thunbergii (Polygonaceae) has been known to have anti-tumoral, anti-angiogenesis, anti-oxidation and anti-inflammation functions. In this study, aerial parts of P. thunbergii were extracted using methanol, chloroform, and ethyl acetate to identify possible anti-bacterial effects. Agar disk diffusion method and time-kill assay were done to evaluate the antibacterial effect of P. thunbergii extracts. Two extracts ethyl acetate (EAE), and chloroform (CFE) were tested against Staphylococcus aureus. As a result, the extract from CFE and EAE showed antibacterial effect against S. aureus. The extract EAE showed the strongest inhibition effect compared to CFE. These results demonstrate that the EAE extract which originated from P. thunbergii can probably play a role as an antibacterial agent.

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Ocimum gratissimum Capped Sulfur Nanoparticles and Antibacterial Efficacy against Multidrug-Resistant Microbes

Asian Journal of Research in Biochemistry ◽

10.9734/ajrb/2020/v7i430151 ◽

2020 ◽

pp. 85-95

Author(s):

Owolabi M. Bankole ◽

Oludare Temitope Osuntokun ◽

Adedapo Adeola ◽

Afolabi Owoeye

Keyword(s):

Staphylococcus Aureus ◽

Oxalic Acid ◽

Plant Extract ◽

Research Work ◽

Multidrug Resistant ◽

Antimicrobial Activities ◽

Clinical Isolates ◽

Ocimum Gratissimum ◽

Salmonella Pullorum ◽

Sulfur Nanoparticles

This manuscript reports for the first time synthesis of sulfur nanoparticles prepared from thiosulphatepentahydrate ( ) using either oxalic acid alone ( ), or mixture of oxalic acid and aqueous solution of Ocimum gratissimum ( ). The synthesized sulfur nanoparticles were obtained in satisfactory yields, and characterized with techniques such asUV-Vis, XRD, SEM, EDX, TEM, and FT-IR. Presence of capping agents: Oxalic acid and biomolecule contents of Ocimum gratissimum were confirmed by FTIR. Crystallinity, morphology, shapes and elemental compositions of as-prepared nanoparticles were confirmed by XRD, SEM, TEM and EDX, respectively. Antimicrobial activities of the prepared sulfur nanoparticles against five (5) multidrug-resistant microbes were used for this research work. This included Staphylococcus aureus, Klebsiella pneumoniae, Escherichia coli, Pseudomonas aeruginosa and Salmonella pullorum. The zone of inhibition of the sulfur nanoparticles tested against selected clinical isolates. Staphylococcus aureus was observed to have the highest susceptibility to sulfur nanoparticles ( ) mediated with Ocimum gratissimum plant extract with diameter of 21.0mm; E.coli and Salmonella P. aeruginosa showed resistance. All tested clinical isolates were resistant to the other sulfur nanoparticles (SNP1) synthesized in the absence of Ocimum gratissimum plant extract.

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Antimicrobial Activities of Teucrium creticum against Reference Microbial Strains and Multi-drug Resistant Bacteria Isolated at an Oncology Ward

Journal of Advances in Microbiology ◽

10.9734/jamb/2019/v17i430149 ◽

2019 ◽

pp. 1-7

Author(s):

Motasem Al-Masri ◽

Ghadeer Omar ◽

Adham Taha ◽

Amira Abu Alsoud ◽

Eman Tawafsha ◽

...

Keyword(s):

Staphylococcus Aureus ◽

Aqueous Extract ◽

Multidrug Resistant ◽

Antimicrobial Activities ◽

Resistant Bacteria ◽

Dilution Method ◽

Bacterial Strains ◽

Patients With Cancer ◽

Oncology Ward ◽

National University

Aim: To determine antimicrobial activity of Teucrium creticum (T. creticum) leaves extract against bacterial and fungal reference strains and multidrug resistant bacteria isolated at an oncology ward. Study Design: Cross-sectional study. Place and Duration of Study: The study was carried out in department of biology and biotechnology in An-Najah National University in cooperation with the laboratory of the hospital of the university. An-Najah National University is located in West Bank in Palestine. The research was performed from 8th of February to the 15th of April 2017. Methodology: Teucrium creticum plant leaves were collected in Palestine, from which aqueous and methanolic extracts were prepared. Antimicrobial activities of T. creticum extracts were determined against reference bacterial and fungal strains as well as against 8 multidrug resistant bacteria isolated at an oncology ward. Antibacterial and anti-yeast activities were determined by Micro broth dilution method, while anti-mold activities were determined by agar dilution method. Teucrium creticum methanolic extract strongly inhibited the growth of the studied reference bacterial strains, which were Staphylococcus aureus (MIC= 1.56 mg/ml) and Shigella sonnie (MIC=3.125 mg/ml). In addition, most of the 8 multi-drug resistant bacterial strains isolated from patients with cancer (Pseudomonas aeruginosa, Staphylococcus aureus, Escherichia Coli and Enterobacter cloacae) were also highly susceptible to methanolic extract (MIC=3.125 mg/ml). Both the Staphylococcus aureus and Shigella sonnie reference strains were inhibited at lower level by the aqueous extract (MIC=12.5 mg/ml). All the bacterial strains isolated from patients with cancer were susceptible to aqueous extract at different levels (3.125 – 25 mg/ml). Epidermophyton floccosum mold and Candida albicans yeast were strongly inhibited by aqueous extract, where the MIC values were 1.56 and 3.125 mg/ml, respectively. Conclusion: T. creticum plant extracts showed promising antimicrobial activities against multidrug resistant bacterial isolates as well as against reference bacterial and fungal strains.

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