scholarly journals In vitro adherence of antibiotic-resistant Escherichia coli to biomaterial surfaces: Effect of conditioning film

2009 ◽  
Vol 11 (1) ◽  
Author(s):  
YB Ngwai ◽  
JA Onaolapo ◽  
JO Ehinmidu ◽  
K Ibrahim
Keyword(s):  
Escherichia Coli ◽  
Antibiotic Resistant ◽  
Biomaterial Surfaces ◽  
Conditioning Film

Mechanisms involved in effects of antimicrobial peptides, bactenectins ChBac3.4, ChBac5, and mini-ChBac7.5Nb, on bacterial cells

2017 ◽  
pp. 43-50
Author(s):  
О.В. Шамова ◽  
М.С. Жаркова ◽  
П.М. Копейкин ◽  
Д.С. Орлов ◽  
Е.А. Корнева
Keyword(s):  
Escherichia Coli ◽  
Antimicrobial Activity ◽  
Innate Immunity ◽  
Infectious Diseases ◽  
Metabolic Activity ◽  
Capra Hircus ◽  
Bacterial Cells ◽  
Antibiotic Resistant ◽  
Resistant Strains

Антимикробные пептиды (АМП) системы врожденного иммунитета - соединения, играющие важную роль в патогенезе инфекционных заболеваний, так как обладают свойством инактивировать широкий спектр патогенных бактерий, обеспечивая противомикробную защиту живых организмов. В настоящее время АМП рассматриваются как потенциальные соединения-корректоры инфекционной патологии, вызываемой антибиотикорезистентными бактериями (АБР). Цель данной работы состояла в изученим механизмов антибактериального действия трех пептидов, принадлежащих к семейству бактенецинов - ChBac3.4, ChBac5 и mini-ChBac7.5Nb. Эти химически синтезированные пептиды являются аналогами природных пролин-богатых АМП, обнаруженных в лейкоцитах домашней козы Capra hircus и проявляющих высокую антимикробную активность, в том числе и в отношении грамотрицательных АБР. Методы. Минимальные ингибирующие и минимальные бактерицидные концентрации пептидов (МИК и МБК) определяли методом серийных разведений в жидкой питательной среде с последующим высевом на плотную питательную среду. Эффекты пептидов на проницаемость цитоплазматической мембраны бактерий для хромогенного маркера исследовали с использованием генетически модифицированного штамма Escherichia coli ML35p. Действие бактенецинов на метаболическую активность бактерий изучали с применением маркера резазурина. Результаты. Показано, что все исследованные пептиды проявляют высокую антимикробную активность в отношении Escherichia coli ML35p и антибиотикоустойчивых штаммов Escherichia coli ESBL и Acinetobacter baumannii in vitro, но их действие на бактериальные клетки разное. Использован комплекс методик, позволяющих наблюдать в режиме реального времени динамику действия бактенецинов в различных концентрациях (включая их МИК и МБК) на барьерную функцию цитоплазматической мембраны и на интенсивность метаболизма бактериальных клеток, что дало возможность выявить различия в характере воздействия бактенецинов, отличающихся по структуре молекулы, на исследуемые микроорганизмы. Установлено, что действие каждого из трех исследованных бактенецинов в бактерицидных концентрациях отличается по эффективности нарушения целостности бактериальных мембран и в скорости подавления метаболизма клеток. Заключение. Полученная информация дополнит существующие фундаментальные представления о механизмах действия пролин-богатых пептидов врожденного иммунитета, а также послужит основой для биотехнологических исследований, направленных на разработку на базе этих соединений новых антибиотических препаратов для коррекции инфекционных заболеваний, вызываемых АБР и являющимися причинами тяжелых внутрибольничных инфекций. Antimicrobial peptides (AMPs) of the innate immunity are compounds that play an important role in pathogenesis of infectious diseases due to their ability to inactivate a broad array of pathogenic bacteria, thereby providing anti-microbial host defense. AMPs are currently considered promising compounds for treatment of infectious diseases caused by antibiotic-resistant bacteria. The aim of this study was to investigate molecular mechanisms of the antibacterial action of three peptides from the bactenecin family, ChBac3.4, ChBac5, and mini-ChBac7.5Nb. These chemically synthesized peptides are analogues of natural proline-rich AMPs previously discovered by the authors of the present study in leukocytes of the domestic goat, Capra hircus. These peptides exhibit a high antimicrobial activity, in particular, against antibiotic-resistant gram-negative bacteria. Methods. Minimum inhibitory and minimum bactericidal concentrations of the peptides (MIC and MBC) were determined using the broth microdilution assay followed by subculturing on agar plates. Effects of the AMPs on bacterial cytoplasmic membrane permeability for a chromogenic marker were explored using a genetically modified strain, Escherichia coli ML35p. The effect of bactenecins on bacterial metabolic activity was studied using a resazurin marker. Results. All the studied peptides showed a high in vitro antimicrobial activity against Escherichia coli ML35p and antibiotic-resistant strains, Escherichia coli ESBL and Acinetobacter baumannii, but differed in features of their action on bacterial cells. The used combination of techniques allowed the real-time monitoring of effects of bactenecin at different concentrations (including their MIC and MBC) on the cell membrane barrier function and metabolic activity of bacteria. The differences in effects of these three structurally different bactenecins on the studied microorganisms implied that these peptides at bactericidal concentrations differed in their capability for disintegrating bacterial cell membranes and rate of inhibiting bacterial metabolism. Conclusion. The obtained information will supplement the existing basic concepts on mechanisms involved in effects of proline-rich peptides of the innate immunity. This information will also stimulate biotechnological research aimed at development of new antibiotics for treatment of infectious diseases, such as severe in-hospital infections, caused by antibiotic-resistant strains.

scholarly journals Relationship Among Antibiotic Residues And Antibacterial Activity Of The Endemic Spurge Honey (Euphorbia Resinifera O. Berg) From Morocco

2020 ◽  
pp. 795
Author(s):  
Rania Benjamaa ◽  
Abdelkarim Moujanni ◽  
Anass Terrab ◽  
Rabiaa Eddoha ◽  
Maryam Benbachir ◽  
...  
Keyword(s):  
Escherichia Coli ◽  
Staphylococcus Aureus ◽  
Antibacterial Activity ◽  
Inhibition Zone ◽  
Health Concern ◽  
Resistant Bacteria ◽  
Antibiotic Residues ◽  
Antibiotic Resistant ◽  
Liquid Chromatography Tandem Mass

Antibiotic-resistant bacteria continue to be of major health concern worldwide. In recent years, several reports and scientific articles claim the contamination of honey by antibiotics, detectable concentrations of antibiotic residues in honey are illegal. They, may cause hypersensitivity or resistance to drug therapy in humans, and are perceived by consumers as undesirable. In this sense, the purpose of this work was to examine the antibacterial activity of the Euphorbia resinifera (E. resinifera) honey against Escherichia coli and Staphylococcus aureus in vitro using the well-agar diffusion assay followed by dilution range to obtain more precise minimum inhibitory concentration values. The second aim is to evaluate the presence of antibiotics in honey using a screening test: Evidence InvestigatorTM, an immuno-enzymatic method for detection of 27 antibiotic residues followed by a liquid chromatography-tandem mass spectrometry (LC-MS/MS) for confirmation of suspect samples; in order to assess the relationship between the presence of antibiotic residues and the antibacterial activity of honey. In this study, a total of 37 E. resinifera honey samples were analyzed. The results show that all samples of honey inhibited the growth of bacteria at the dilutions at 50% (v/v); the highest inhibition zone (25.98 ± 0.11 mm) was recorded from sample 5 for Staphylococcus aureus and (13.84 ± 1.10 mm) in sample 17 for Escherichia coli and that 50% (v/v) dilutions showed significant antibacterial effect compared to other dilutions (6.25, 12.5, 25% (v/v)). In all samples, there were no antibiotic residues detected except for one showing the detection of Trimethoprim at 6.48 µg kg-1. Our research is one of the first studies that relate the he relationship between the presence of antibiotic residues and the antibacterial activity of Euphorbia resinifera honey and showed that the antibacterial activity of honey might be due to the high osmotic nature, a low pH, its content of phenolic compounds and hydrogen peroxide and also to its content of methylglyoxal.

In vitro activity of mastoparan-AF alone and in combination with clinically used antibiotics against multiple-antibiotic-resistant Escherichia coli isolates from animals

Peptides ◽  
2012 ◽  
Vol 36 (1) ◽  
pp. 114-120 ◽  
Author(s):  
Chun-Hsien Lin ◽  
Roger F. Hou ◽  
Ching-Lin Shyu ◽  
Wei-Yau Shia ◽  
Chuen-Fu Lin ◽  
...  
Keyword(s):  
Escherichia Coli ◽  
Vitro Activity ◽  
In Vitro Activity ◽  
Antibiotic Resistant

scholarly journals Sub-lethal Concentrations of Phytochemicals (Carvacrol and Oregano) Select for Reduced Susceptibility Mutants of Escherichia coli O23:H52

2020 ◽  
Vol 69 (1) ◽  
pp. 121-125
Author(s):  
AFNAN A. AL-MNASER ◽  
MARTIN J. WOODWARD
Keyword(s):  
Escherichia Coli ◽  
Antibiotic Resistance ◽  
Coli Strain ◽  
Whole Genome ◽  
Avian Pathogenic Escherichia Coli ◽  
Antibiotic Resistant ◽  
E Coli ◽  
Pathogenic Escherichia Coli ◽  
Survival Mechanisms

In vitro studies aimed at studying the mechanism of action of carvacrol and oregano as natural anti-bacterial agents to control multiple antibiotic-resistant avian pathogenic Escherichia coli (APEC) strain O23:H52 isolated from chicken were performed. Derivatives with increased minimum inhibitory concentrations (MIC) to the phytochemicals were selected after growing Escherichia coli (E. coli) strain O23:H52 at sub-lethal concentrations of carvacrol and oregano for a period of 60 days. Whole-genome sequencing (WGS) of two derivatives revealed a missense mutation in cadC and marR: the genes responsible for survival mechanisms and antibiotic resistance by efflux, respectively.

scholarly journals Multidrug-Resistant Avian Pathogenic Escherichia coli Strains and Association of Their Virulence Genes in Bangladesh

2020 ◽  
Author(s):  
Otun Saha ◽  
M. Nazmul Hoque ◽  
Ovinu Kibria Islam ◽  
Md. Mizanur Rahaman ◽  
Munawar Sultana ◽  
...  
Keyword(s):  
Escherichia Coli ◽  
Virulence Genes ◽  
Multidrug Resistant ◽  
Antibiotic Resistant ◽  
E Coli ◽  
Molecular Approaches ◽  
Clade B ◽  
High Prevalence ◽  
Resistance Patterns

AbstractThe avian pathogenic Escherichia coli (APEC) strains are the chief etiology of avian colibacillosis worldwide. The present study investigated the circulating phylotypes, existence of virulence genes (VGs) and antimicrobial resistance (AMR) in 392 APEC isolates, obtained from 130 samples belonged to six farms using both phenotypic and PCR-based molecular approaches. Congo red binding (CRB) assay confirmed 174 APEC isolates which were segregated into 10, 9 and 8 distinctive genotypes by RAPD assay (discriminatory index, D=0.8707), BOX-PCR (D=0.8591) and ERIC-PCR (D=0.8371), respectively. The combination of three phylogenetic markers (chuA, yjaA and DNA fragment TspE4.C2) classified APEC isolates into B23 (37.36%), A1 (33.91%), D2 (11.49%), B22 (9.20%) and B1 (8.05%) phylotypes. Majority of the APEC isolates (75-100%) harbored VGs (ial, fimH, crl, papC and cjrC), and of them, VGs (papC and cjrC) and phylotypes (D2 and B2) of APEC had significant (p=0.004) association with colibacillosis. Phylogenetic analysis showed two distinct clades (Clade A and Clade B) of APEC where Clade A had 98-100.0% similarity with E. coli APEC O78 and E. coli EHEC strains, and Clade B had closest relationship with E. coli O169:H41 strain. Interestingly, phylogroups B2 and D2 were found in the APEC strains of both clades while the strains from phylogroups A1 and B1 were found in clade A only. In this study, 81.71% of the isolates were biofilm formers and possessed plasmids of varying ranges (1.0 to 54 kb). In vitro antibiogram profiling revealed that 100.0% isolates were resistant to ≥3 antibiotics, of which61.96%, 55.24, 53.85, 51.16 and 45.58 % isolates in phylotypes B1, D2, B22, B23 and A1, respectively were these antimicrobials. The resistance patterns varied among different phylotypes, notably in phylotype B22 showing the highest resistance to ampicillin (90.91%), nalidixic acid (90.11%), tetracycline (83.72%) and nitrofurantoin (65.12%). Correspondence analysis also showed significant correlation of phylotypes with CRB (p=0.008), biofilm formation (p=0.02), drug resistance (p=0.03) and VGs (p=0.06). This report demonstrated that B2 and A1 phylotypes are dominantly circulating APEC phylotypes in Bangladesh; however, B2 and D2 are strongly associated with the pathogenicity. A high prevalence of antibiotic resistant APEC strains from different phylotypes suggest to use of organic antimicrobial compounds, and/or metals, and the rotational use of antibiotics in the poultry farms in Bangladesh.

scholarly journals In Vitro Activity of Rifabutin and Rifampin against Antibiotic-Resistant Acinetobacter baumannii, Escherichia coli, Staphylococcus aureus, Pseudomonas aeruginosa, and Klebsiella pneumoniae

mSphere ◽  
2021 ◽  
Author(s):  
Bosul Lee ◽  
Jun Yan ◽  
Amber Ulhaq ◽  
Sarah Miller ◽  
Wonjae Seo ◽  
...  
Keyword(s):  
Escherichia Coli ◽  
Staphylococcus Aureus ◽  
Pseudomonas Aeruginosa ◽  
Klebsiella Pneumoniae ◽  
General Effect ◽  
In Vitro Activity ◽  
Antibiotic Resistant ◽  
Content Type

Rifabutin has been recently described as a potential adjunctive therapy for antibiotic-resistant A. baumannii infections due to hypersensitivity in iron-depleted media, which may more closely mimic an in vivo environment. Here, we report that this hyperactivity is specific for A. baumannii , rather than being a general effect for other pathogens.

Molecular Docking Approaches to Suggest the Anti-Mycobacterial Targets of Natural Products

2020 ◽  
Author(s):  
Rafael Baptista ◽  
Sumana Bhowmick ◽  
Shen Jianying ◽  
Luis Mur
Keyword(s):  
Natural Products ◽  
Molecular Docking ◽  
Free Energies ◽  
Antibiotic Resistant ◽  
Drug Lead ◽  
Bisbenzylisoquinoline Alkaloids ◽  
Docking Approach ◽  
Global Threat ◽  
Physicochemical And Structural Properties

Tuberculosis (TB) is a major global threat mostly due to the development of antibiotic resistant forms of Mycobacterium tuberculosis, the causal agent of the disease. Driven by the pressing need for new anti-mycobacterial agents, several natural products (NPs) have been shown to have in vitro activities against M. tuberculosis. The utility of any NP as a drug lead is augmented when the anti-mycobacterial target(s) is unknown. To suggest these, we used a molecular docking approach to predict the interactions of 53 selected anti-mycobacterial NPs against known ‘druggable’ mycobacterial targets ClpP1P2, DprE1, InhA, KasA, PanK, PknB and Pks13. The docking scores / binding free energies were predicted and calculated using AutoDock Vina along with physicochemical and structural properties of the NPs, using PaDEL descriptors. These were compared to the established inhibitor (control) drugs for each mycobacterial target. The specific interactions of the bisbenzylisoquinoline alkaloids 2-nortiliacorinine, tiliacorine and 13’-bromotiliacorinine against the targets PknB and DprE1 (-11.4, -10.9 and -9.8 kcal.mol-1 ; -12.7, -10.9 and -10.3 kcal.mol-1 , respectively) and the lignan αcubebin and Pks13 (-11.0 kcal.mol-1 ) had significantly superior docking scores compared to controls. Our approach can be used to suggest predicted targets for the NP to be validated experimentally but these in silico steps are likely to facilitate drug optimisation.

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