Increasing of the Aminoglicosyde Antibiotic Activity Against a Multidrug-Resistant E. coli by Turnera ulmifolia L. and Chlorpromazine

2009 ◽  
Vol 11 (4) ◽  
pp. 332-335 ◽  
Author(s):  
Henrique D. M. Coutinho ◽  
José G. M. Costa ◽  
Edeltrudes O. Lima ◽  
Vivyanne S. Falcão-Silva ◽  
José P. Siqueira-Júnior
Keyword(s):  
Bacterial Resistance ◽  
Inhibitory Concentration ◽  
Ethanol Extract ◽  
Multidrug Resistant ◽  
Coli Strain ◽  
Minimal Bactericidal Concentration ◽  
Efflux System ◽  
E Coli ◽  
Turnera Ulmifolia ◽  
Conventional Antibiotics

In this study, an ethanol extract of Turnera ulmifolia L. (EETU) and chlorpromazine (CPZ) were tested for their antimicrobial activity alone or in combination with conventional antibiotics against two strains of Escherichia coli (E. coli). The growth of neither E. coli strain was inhibited by the extract. The minimal inhibitory concentration (MIC) and minimal bactericidal concentration values were ≥1 mg/ml for both the strains of E. coli. However, the extract did increase the antimicrobial effects of amikacin, neomycin, and tobramycin. A similar effect of CPZ on amikacin, kanamycin, and tobramycin indicated the involvement of an efflux system in the resistance to these aminoglycosides. Results suggest that extracts from T. ulmifolia could be used as a plant-derived natural product with resistance-modifying activity, constituting a new weapon against bacterial resistance to antibiotics.

Antimicrobial Peptides and their Multiple Effects at Sub-Inhibitory Concentrations

2020 ◽  
Vol 20 (14) ◽  
pp. 1264-1273 ◽  
Author(s):  
Bruno Casciaro ◽  
Floriana Cappiello ◽  
Walter Verrusio ◽  
Mauro Cacciafesta ◽  
Maria Luisa Mangoni
Keyword(s):  
Antimicrobial Peptides ◽  
Inhibitory Concentration ◽  
Multidrug Resistant ◽  
Mechanisms Of Action ◽  
New Drugs ◽  
Lead Compounds ◽  
Bacterial Pathogenicity ◽  
Growth Inhibitory ◽  
Resistant Strains ◽  
Conventional Antibiotics

The frequent occurrence of multidrug-resistant strains to conventional antimicrobials has led to a clear decline in antibiotic therapies. Therefore, new molecules with different mechanisms of action are extremely necessary. Due to their unique properties, antimicrobial peptides (AMPs) represent a valid alternative to conventional antibiotics and many of them have been characterized for their activity and cytotoxicity. However, the effects that these peptides cause at concentrations below the minimum growth inhibitory concentration (MIC) have yet to be fully analyzed along with the underlying molecular mechanism. In this mini-review, the ability of AMPs to synergize with different antibiotic classes or different natural compounds is examined. Furthermore, data on microbial resistance induction are reported to highlight the importance of antibiotic resistance in the fight against infections. Finally, the effects that sub-MIC levels of AMPs can have on the bacterial pathogenicity are summarized while showing how signaling pathways can be valid therapeutic targets for the treatment of infectious diseases. All these aspects support the high potential of AMPs as lead compounds for the development of new drugs with antibacterial and immunomodulatory activities.

In Vitro Antibacterial activity of ethanolic extract of Myrsine africana against laboratory Strains of Pathogenic Organisms

2016 ◽  
Vol 5 (04) ◽  
pp. 4512
Author(s):  
Jackie K. Obey ◽  
Anthoney Swamy T* ◽  
Lasiti Timothy ◽  
Makani Rachel
Keyword(s):  
Antibacterial Activity ◽  
Minimum Inhibitory Concentration ◽  
Inhibitory Concentration ◽  
Ethanolic Extract ◽  
Ethanol Extract ◽  
E Coli ◽  
Zones Of Inhibition ◽  
In Vitro Antibacterial Activity ◽  
Myrsine Africana

The determination of the antibacterial activity (zone of inhibition) and minimum inhibitory concentration of medicinal plants a crucial step in drug development. In this study, the antibacterial activity and minimum inhibitory concentration of the ethanol extract of Myrsine africana were determined for Escherichia coli, Bacillus cereus, Staphylococcus epidermidis and Streptococcus pneumoniae. The zones of inhibition (mm±S.E) of 500mg/ml of M. africana ethanol extract were 22.00± 0.00 for E. coli,20.33 ±0.33 for B. cereus,25.00± 0.00 for S. epidermidis and 18. 17±0.17 for S. pneumoniae. The minimum inhibitory concentration(MIC) is the minimum dose required to inhibit growth a microorganism. Upon further double dilution of the 500mg/ml of M. africana extract, MIC was obtained for each organism. The MIC for E. coli, B. cereus, S. epidermidis and S. pneumoniae were 7.81mg/ml, 7.81mg/ml, 15.63mg/ml and 15.63mg/ml respectively. Crude extracts are considered active when they inhibit microorganisms with zones of inhibition of 8mm and above. Therefore, this study has shown that the ethanol extract of M. africana can control the growth of the four organisms tested.

scholarly journals Independent Behavior of Commensal Flora for Carriage of Fluoroquinolone-Resistant Bacteria in Patients at Admission

2010 ◽  
Vol 54 (12) ◽  
pp. 5193-5200 ◽  
Author(s):  
Victoire de Lastours ◽  
Françoise Chau ◽  
Florence Tubach ◽  
Blandine Pasquet ◽  
Etienne Ruppé ◽  
...  
Keyword(s):  
Risk Factors ◽  
Bacterial Resistance ◽  
Care Facility ◽  
Health Care Facility ◽  
Epidemiological Data ◽  
Multidrug Resistant ◽  
Resistant Bacteria ◽  
E Coli ◽  
Commensal Flora ◽  
Resistant Strains

ABSTRACT The important role of commensal flora as a natural reservoir of bacterial resistance is now well established. However, whether the behavior of each commensal flora is similar to that of other floras in terms of rates of carriage and risk factors for bacterial resistance is unknown. During a 6-month period, we prospectively investigated colonization with fluoroquinolone-resistant bacteria in the three main commensal floras from hospitalized patients at admission, targeting Escherichia coli in the fecal flora, coagulase-negative Staphylococcus (CNS) in the nasal flora, and α-hemolytic streptococci in the pharyngeal flora. Resistant strains were detected on quinolone-containing selective agar. Clinical and epidemiological data were collected. A total of 555 patients were included. Carriage rates of resistance were 8.0% in E. coli, 30.3% in CNS for ciprofloxacin, and 27.2% in streptococci for levofloxacin; 56% of the patients carried resistance in at least one flora but only 0.9% simultaneously in all floras, which is no more than random. Risk factors associated with the carriage of fluoroquinolone-resistant strains differed between fecal E. coli (i.e., colonization by multidrug-resistant bacteria) and nasal CNS (i.e., age, coming from a health care facility, and previous antibiotic treatment with a fluoroquinolone) while no risk factors were identified for pharyngeal streptococci. Despite high rates of colonization with fluoroquinolone-resistant bacteria, each commensal flora behaved independently since simultaneous carriage of resistance in the three distinct floras was uncommon, and risk factors differed. Consequences of environmental selective pressures vary in each commensal flora according to its local specificities (clinical trial NCT00520715 [http://clinicaltrials.gov/ct2/show/NCT00520715 ]).

Urban wastewater disinfection for agricultural reuse: effect of solar driven AOPs in the inactivation of a multidrug resistant E. coli strain

2015 ◽  
Vol 178 ◽  
pp. 65-73 ◽  
Author(s):  
Giovanna Ferro ◽  
Antonino Fiorentino ◽  
María Castro Alferez ◽  
M. Inmaculada Polo-López ◽  
Luigi Rizzo ◽  
...  
Keyword(s):  
Multidrug Resistant ◽  
Coli Strain ◽  
Urban Wastewater ◽  
E Coli ◽  
Wastewater Disinfection

scholarly journals Effects of biocide exposure on P. Aeruginosa, E. coli and A. Baumannii complex isolates from hospital and household environments

Infectio ◽  
2017 ◽  
Vol 21 (4) ◽  
Author(s):  
Daniel Felipe Vásquez-Giraldo ◽  
Gerardo Andrés Libreros-Zúñiga ◽  
María Del Pilar Crespo-Ortiz
Keyword(s):  
Escherichia Coli ◽  
Benzalkonium Chloride ◽  
Inhibitory Concentration ◽  
Minimum Bactericidal Concentration ◽  
Multidrug Resistant ◽  
Environmental Isolates ◽  
E Coli ◽  
Acinetobacter Baumannii Complex ◽  
Cleaning And Disinfection ◽  
Reference Strains

Background: Bacterial responses to biocide exposure and its effects on survival and persistence remain to be studied in greater detail.Aim: To analyse the viability and survival of environmental isolates from household and hospital settings after biocide exposure.Methods: The minimum inhibitory concentration (MIC) and minimum bactericidal concentration (MBC) of chlorhexidine (CHxG), benzalkonium chloride (BAC) and triclosan (TC) were determined in isolates of Pseudomonas aeruginosa, Acinetobacter baumannii complex and Escherichia coli collected from hospital and households environments. Viability was monitored after exposure and removal of biocides using agar cultures and flow cytometry.Findings: P. aeruginosa isolates showed greater tolerance for all biocides tested whereas A. baumannii complex and E. coli were less tolerant.When compared with reference strains, biocide tolerance was up to 8 to 13-fold higher for TC and BAC respectively. Flow cytometry showed that biocide exposure may induce viable but non-growing states in P. aeruginosa and E. coli isolates before becoming fully replicative. Changes in the susceptibility profile in one isolate of A. baumannii complex were observed after biocide exposure.Discussion: Bacteria isolates from hospital and households were able to recover after biocide exposure at bactericidal concentrations favouring persistence and spread of biocide-tolerant strains. This study reinforces that cleaning compliance should be monitored by non-culture based tests. Novel formulations in cleaning and disinfection protocols should be revisited in hospitals harbouring P. aeruginosa and A. baumannii multidrug resistant isolates.

scholarly journals Design, Overproduction and Purification of the Chimeric Phage Lysin MLTphg Fighting against Staphylococcus aureus

Processes ◽  
2020 ◽  
Vol 8 (12) ◽  
pp. 1587
Author(s):  
Feng Wang ◽  
Xiaohang Liu ◽  
Zhengyu Deng ◽  
Yao Zhang ◽  
Xinyu Ji ◽  
...  
Keyword(s):  
Staphylococcus Aureus ◽  
Bacterial Infections ◽  
Antimicrobial Agents ◽  
Multidrug Resistant ◽  
Resistant Bacteria ◽  
Antibiotic Resistant ◽  
E Coli ◽  
Conventional Antibiotics ◽  
Phage Lysin ◽  
Shed Light

With the increasing spread of multidrug-resistant bacterial pathogens, it is of great importance to develop alternatives to conventional antibiotics. Here, we report the generation of a chimeric phage lysin, MLTphg, which was assembled by joining the lysins derived from Meiothermus bacteriophage MMP7 and Thermus bacteriophage TSP4 with a flexible linker via chimeolysin engineering. As a potential antimicrobial agent, MLTphg can be obtained by overproduction in Escherichia coli BL21(DE3) cells and the following Ni-affinity chromatography. Finally, we recovered about 40 ± 1.9 mg of MLTphg from 1 L of the host E. coli BL21(DE3) culture. The purified MLTphg showed peak activity against Staphylococcus aureus ATCC6538 between 35 and 40 °C, and maintained approximately 44.5 ± 2.1% activity at room temperature (25 °C). Moreover, as a produced chimera, it exhibited considerably improved bactericidal activity against Staphylococcus aureus (2.9 ± 0.1 log10 reduction was observed upon 40 nM MLTphg treatment at 37 °C for 30 min) and also a group of antibiotic-resistant bacteria compared to its parental lysins, TSPphg and MMPphg. In the current age of growing antibiotic resistance, our results provide an engineering basis for developing phage lysins as novel antimicrobial agents and shed light on bacteriophage-based strategies to tackle bacterial infections.

scholarly journals 611. Fosfomycin Resistance of Multidrug-Resistant Escherichia coli and Mechanisms of Fosfomycin Resistance

2019 ◽  
Vol 6 (Supplement_2) ◽  
pp. S285-S285
Author(s):  
Hyeri Seok ◽  
Ji Hoon Jeon ◽  
Hee Kyoung Choi ◽  
Won Suk Choi ◽  
Dae Won Park ◽  
...  
Keyword(s):  
Escherichia Coli ◽  
Antimicrobial Agents ◽  
Multidrug Resistant ◽  
Resistance Rate ◽  
Coli Strain ◽  
Resistant Bacteria ◽  
E Coli ◽  
Broth Microdilution Method ◽  
Fosfomycin Resistance

Abstract Background Fosfomycin is one of the antibiotics that may be a candidate for the next-generation antimicrobial agents againt multidrug-resistant bacteria. To date, it is known that the resistance rate is not high for Escherichia coli. However, it is necessary to update the fosfomycin resistance rates in E. coli according to the studies that extended spectrum β-lactamase (ESBL) producing E. coli strains are highly resistance to fosfomycin. We evaluated the resistance rate of fosfomycin, the resistant mechanism of fosfomycin in E. coli, and the activity of fosfomycin against susceptible and resistant strains of E. coli. Methods A total of 283 clinical isolates was collected from patients with Escherichia coli species during the period of January 2018 to June 2018, in three tertiary hospitals of Republic of Korea. In vitro antimicrobial susceptibility tests were performed in all E. coli isolates using the broth microdilution method according to the Clinical and Laboratory Standard Institute (CLSI). Multilocus sequence typing (MLST) of the Oxford scheme was conducted to determine the genotypes of E. coli isolated. Fosfomycin genes were investigated for all fosfomycin-resistant E. coli strains. Results The overall resistance rate to fosfomycin was 10.2%, compared with 53.4%, 46.3%, 41.3%, 31.1%, 10.6%, 2.5%, and 2.1% for ciprofloxacin, cefixime, cefepime, piperacillin/tazobactam, colistin, ertapenem, and amikacin, respectively. The 29 fosfomycin-resistant isolates did not show a clonal pattern on the phylogenetic tree. MurA and glp genes were identified in all strains. FosA3 were identified in two strains and uhp gene were identified in 4 strains. In time-kill curve studies, fosfomycin was more bactericidal than cefixime against all sensitive E. coli strain. Morever, fosfomycin was more bactericidal than piperacillin/tazobactam against ESBL-producing E. coli strain. Conclusion The resistant rate of fosfomycin to E. coli is still low. Fosfomycin was active against E. coli including ESBL producing strains. Disclosures All authors: No reported disclosures.

Direct antibacterial and antibiotic resistance modulatory activity of chalcones synthesized from the natural product 2-hydroxy-3,4,6-trimethoxyacetophenone

2020 ◽  
Vol 367 (15) ◽  
Author(s):  
Thiago Sampaio de Freitas ◽  
Jayze da Cunha Xavier ◽  
Raimundo L S Pereira ◽  
Janaina E Rocha ◽  
Dédora F Muniz ◽  
...  
Keyword(s):  
Natural Product ◽  
Bacterial Resistance ◽  
Inhibitory Concentration ◽  
Multidrug Resistant ◽  
Antibiotic Activity ◽  
Antibacterial Drug ◽  
Clinical Use ◽  
Synergistic Interactions ◽  
Resistance Reversal ◽  
Over Time

ABSTRACT Antibiotic for clinical use lose its effectiveness over time due to bacterial resistance. In this work, four chalcones with modifications in their ligands were synthesized from the natural product 2-hydroxy-3,4,6-trimethoxyacetophenone, characterized by nuclear magnetic resonance (NMR) and infrared spectroscopy, and tested in bacterial models to investigate the direct and modifiers effects of the antibiotic activity of these four novel chalcones. The tests followed the broth microdilution methodology to obtain the Minimum Inhibitory Concentration (MIC). The MIC/8 of the products were used in the resistance reversion test. The chalcone 2 showed the best result in terms of direct activity, with MIC 645 μg/mL for Staphylococcus aureus and 812 μg/mL for Escherichia coli. While, for the bacterial resistance reversal test, the chalcones presented several synergistic interactions, being that chalcone 4 had the best interaction with the tested antibiotics. It was found that the type of ligand, as well as its position in the ring, interferes in the modulation of the antibiotic activity. Our results show that chalcones are strong candidates to be used as antibacterial drug or in combination with antibiotics for the treatment of infections caused by multidrug-resistant (MDR) strains.

scholarly journals Virulence Potential of a Multidrug-Resistant Escherichia coli Strain Belonging to the Emerging Clonal Group ST101-B1 Isolated from Bloodstream Infection

2020 ◽  
Vol 8 (6) ◽  
pp. 827 ◽  
Author(s):  
Ana Carolina M. Santos ◽  
Rosa M. Silva ◽  
Tiago B. Valiatti ◽  
Fernanda F. Santos ◽  
José F. Santos-Neto ◽  
...  
Keyword(s):  
Escherichia Coli ◽  
Antimicrobial Resistance ◽  
Bloodstream Infection ◽  
Galleria Mellonella ◽  
Multidrug Resistant ◽  
Coli Strain ◽  
Pathogenic Potential ◽  
E Coli ◽  
Antimicrobial Resistance Genes

Escherichia coli EC121 is a multidrug-resistant (MDR) strain isolated from a bloodstream infection of an inpatient with persistent gastroenteritis and T-zone lymphoma that died due to septic shock. Despite causing an extraintestinal infection, previous studies showed that it did not have the usual characteristics of an extraintestinal pathogenic E. coli. Instead, it belonged to phylogenetic group B1 and harbored few known virulence genes. To evaluate the pathogenic potential of strain EC121, an extensive genome sequencing and in vitro characterization of various pathogenicity-associated properties were performed. The genomic analysis showed that strain EC121 harbors more than 50 complete virulence genetic clusters. It also displays the capacity to adhere to a variety of epithelial cell lineages and invade T24 bladder cells, as well as the ability to form biofilms on abiotic surfaces, and survive the bactericidal serum complement activity. Additionally, EC121 was shown to be virulent in the Galleria mellonella model. Furthermore, EC121 is an MDR strain harboring 14 antimicrobial resistance genes, including blaCTX-M-2. Completing the scenario, it belongs to serotype O154:H25 and to sequence type 101-B1, which has been epidemiologically linked to extraintestinal infections as well as to antimicrobial resistance spread. This study with E. coli strain EC121 shows that clinical isolates considered opportunistic might be true pathogens that go underestimated.

scholarly journals High-Throughput Screen Identifying the Thiosemicarbazone NSC319726 Compound as a Potent Antimicrobial Lead Against Resistant Strains of Escherichia coli

Biomolecules ◽  
2018 ◽  
Vol 8 (4) ◽  
pp. 166 ◽  
Author(s):  
Carmen Sadaka ◽  
Peter Damborg ◽  
Jeffrey L. Watts
Keyword(s):  
Escherichia Coli ◽  
High Throughput ◽  
Multidrug Resistant ◽  
Coli Strain ◽  
High Throughput Screen ◽  
Lead Discovery ◽  
E Coli ◽  
Resistant Strains ◽  
Susceptibility Profiles ◽  
Antibiotic Discovery

Antibiotic discovery is vital when considering the increasing antimicrobial resistance threat. The aim of this work was to provide a high-throughput screen (HTS) assay using multidrug-resistant Escherichia coli strains to enable further research into antimicrobial lead discovery and identify novel antimicrobials. This study describes a primary HTS of a diverse library of 7884 small molecules against a susceptible E. coli strain. A secondary screening of 112 molecules against four E. coli strains with different susceptibility profiles revealed NSC319726 as a potential antimicrobial lead serving as a novel template. NSC319726 is a good candidate for an analoguing program.

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