Modulation of the drug resistance by Platonia insignis Mart. extract, ethyl acetate fraction and Morelloflavone/Volkensiflavone (biflavonoids) in Staphylococcus aureus strains overexpressing efflux pump genes

2020 ◽  
Vol 21 ◽  
Author(s):  
Andressa Kelly Ferreira e Silva ◽  
Antonielly Campinho dos Reis ◽  
Emanuelly Elanny Andrade Pinheiroc ◽  
Jonas Nascimento de Sousa ◽  
Felipe Araújo de Alcântara Oliveira ◽  
...  

Background: Microbial resistance to antibiotics is a global public health problem, which requires urgent attention. Platonia insignis is a native species from the eastern Brazilian Amazon, used in the treatment of burns and wounds. Objectives: To evaluate the antimicrobial activity of the hydroalcoholic extract of P. insignis (PIHA), the ethyl acetate fraction (PIAE), and its subfraction containing a mixture of biflavonoids (BF). Moreover, the effect of these natural products on the antibiotic activity against S. aureus strains overexpressing efflux pump genes was also evaluated. Methods: Minimal inhibitory concentrations were determined against different species of microorganisms. To evaluate the modulatory effect on the Norfloxacin-resistance, the MIC of this antibiotic was determined in the absence and presence of the natural products at subinhibitory concentrations. Inhibition of the EtBr efflux assays were conducted in the absence or presence of the natural products. Results: PIHA showed a microbicidal effect against S. aureus and C. albicans, while PIAE was bacteriosctatic for S. aureus. PIAE and BF at subinhibitory concentrations were able to reduce the MIC of Norfloxacin acting as modulating agents. BF was able to inhibit the efflux of EtBr efflux in S. aureus strains overexpressing specific efflux pump genes. Conclusion: P. inignisis a source of efflux pump inhibitors, including volkensiflavone and morelloflavone which were able to potentiate the Norfloxacin activity by NorA inhibition, being also able to inhibit QacA/B, TetK and MsrA. Volkensiflavone and morelloflavone could be used as adjuvant in the antibiotic therapy of multidrug resistant S. aureus strains overexpressing efflux pumps.

1988 ◽  
Vol 43 (10) ◽  
pp. 1347-1350 ◽  
Author(s):  
Shaheen Bano ◽  
Mohammad Shaiq Ali ◽  
Viqar Uddin Ahmad

Abstract From the ethyl acetate fraction of methanolic extract of red alga, L.pinnatifida, a new halogenated sesquiterpene named as pinnatifidone [1] has been isolated and the structure of this compound has been elucidated with the help of intensive spectroscopic studies.


2019 ◽  
Vol 2019 ◽  
pp. 1-8 ◽  
Author(s):  
Oumer Abdu Muhie

Background. In the last decades, medicines have had an unprecedented positive effect on health, leading to reduced mortality and disease burden and consequently to an improved quality of life. The rapid and ongoing spread of antimicrobial-resistant organisms threatens our ability to successfully treat a growing number of infectious diseases. In the absence of the development of new generations of antibiotic drugs, appropriate use of existing antibiotics is needed to ensure the long-term availability of effective treatment for bacterial infections. Irrational use of antibiotics is an ongoing global public health problem that deserves more attention. This review is conducted to evaluate the prevalence of inappropriate antibiotic utilization and resistance to antibiotics in Ethiopia. Methods. Electronic search in PubMed/MEDLINE and Google was used to find published literature with reference lists of relevant articles searched manually. Titles and abstracts were initially screened for eligibility. The full texts of articles judged to be eligible were reviewed if they meet the inclusion criteria. Data were extracted on important variables like the sample size, region of the study, the inappropriate antibiotic use, bacterial detection rate, multidrug resistance pattern, and more other variables. Microsoft Excel was used for data extraction. Quantitative analysis was performed using STATA version 11. Results. The electronic searches identified 193 articles of which 33 were found eligible. The random-effects model was used to provide point estimates (with 95% confidence interval (CI)) of bacterial detection rate, inappropriate antibiotic use, and multidrug resistance rate to account for heterogeneity. The pooled bacteria detection rate was 29.1 with 95% CI (16.6–41.7). The pooled prevalence of multidrug resistant strains identified was 59.7% (95% CI: 43.5–75.9). The pooled estimate of inappropriate antibiotic use was 49.2% (95% CI: 32.2–66.2). The pooled proportion of self-antibiotic prescription was 43.3% (95% CI: 15.7–70.9). Other reasons for inappropriate antibiotic use included a wrong indication, wrong duration, improper route of administration, use of leftover antibiotics from a family member, and immature discontinuation of antibiotics. Conclusion and Recommendations. Inappropriate antibiotic use is a huge problem in Ethiopia, and many bacteria were resistant to commonly used antibiotics and similarly, multidrug-resistant bacterial strains are numerous. Appropriate antibiotic use should be ensured by prohibiting over-the-counter sale of antibiotics and strengthening antimicrobial stewardship.


PLoS ONE ◽  
2021 ◽  
Vol 16 (6) ◽  
pp. e0253312
Author(s):  
Marguerite E. M. Nikiema ◽  
Maria Pardos de la Gandara ◽  
Kiswensida A. M. Compaore ◽  
Absétou Ky Ba ◽  
Karna D. Soro ◽  
...  

Background Gastrointestinal infections are a global public health problem. In Burkina Faso, West Africa, exposure to Salmonella through the consumption of unhygienic street food represents a major risk of infection requiring detailed evaluation. Methods Between June 2017 and July 2018, we sampled 201 street food stalls, in 11 geographic sectors of Ouagadougou, Burkina Faso. We checked for Salmonella contamination in 201 sandwiches (one per seller), according to the ISO 6579:2002 standard. All Salmonella isolates were characterized by serotyping and antimicrobial susceptibility testing, and whole-genome sequencing was performed on a subset of isolates, to investigate their phylogenetic relationships and antimicrobial resistance determinants. Results The prevalence of Salmonella enterica was 17.9% (36/201) and the Salmonella isolates belonged to 16 different serotypes, the most frequent being Kentucky, Derby and Tennessee, with five isolates each. Six Salmonella isolates from serotypes Brancaster and Kentucky were multidrug-resistant (MDR). Whole-genome sequencing revealed that four of these MDR isolates belonged to the emergent S. enterica serotype Kentucky clone ST198-X1 and to an invasive lineage of S. enterica serotype Enteritidis (West African clade). Conclusion This study reveals a high prevalence of Salmonella spp. in sandwiches sold in Ouagadougou. The presence of MDR Salmonella in food on sale detected in this study is also matter of concern.


2021 ◽  
Vol 12 (6) ◽  
pp. 7523-7531

Phytochemical studies on Croton species have identified the presence of secondary metabolites responsible for a wide variety of pharmacological activities, among them antimicrobial activity. Research for new substances with antimicrobial activity derived from natural products can give a major contribution to human health worldwide by finding more efficient and fewer toxic formulas in the race against pathogenic microorganisms' resistance. Among bacterial pathogens, Staphylococcus aureus species, despite being present in the skin and nasal mucosa, can cause many infections and diseases. These opportunists reach debilitated people in hospitals and are challenging to treat. Here, we performed the structural characterization, determination of antibiotic activity, and MepA efflux pump inhibition potential against S. aureus of the chalcone (2E, 4E) -1- (2-hydroxy-3,4,6-trimethoxyphenyl)-5-phenylpenta-2,4-dien-1-one, derived from natural products 2-hydroxy-3,4,6-trimethoxyacetophenone isolated from Croton anisodontus and cinnamaldehyde. The chalcone was synthesized by the Claisen-Schmidt condensation. In addition, microbiological tests were performed to investigate the antibacterial activity, modulator potential, and efflux pump inhibition against the S. aureus multi-resistant strains. MIC values obtained to chalcone were not clinically relevant (MIC ≥ 1024 µg/mL). However, chalcone hampers the binding of the antibiotic to the binding site of the MepA efflux pump. It acts as a competitive inhibitor, being expelled from the bacteria in place of the antibiotic and potentiating ciprofloxacin's action against multidrug-resistant bacterial strains of K2068. Therefore, chalcone can be used as a base for substance design with antibiotic modifying activity.


2021 ◽  
Vol 2021 ◽  
pp. 1-15
Author(s):  
Babita Aryal ◽  
Purushottam Niraula ◽  
Karan Khadayat ◽  
Bikash Adhikari ◽  
Dadhiram Khatri Chhetri ◽  
...  

Natural products have been the center of attraction ever since they were discovered. Among them, plant-based natural products were popular as analgesics, anti-inflammatory, antidiabetic, and cosmetics and possess widespread biotechnological applications. The use of plant products as cosmetics and therapeutics is deep-rooted in Nepalese society. Although there are few ethnobotanical studies conducted, extensive research of these valuable medicinal plants has not been a priority due to the limitation of technology and infrastructure. Here, we selected 4 traditionally used medicinal plants to examine their bioactive properties and their enzyme inhibition potential. α-Glucosidase and α-amylase inhibitory activities were investigated using an in vitro model followed up by antioxidant and antimicrobial activities. The present study shows that ethyl acetate fraction of Melastoma melabathrium (IC50 9.1 ± 0.3 µg/mL) and water fraction Acacia catechu (IC50 9.0 ± 0.6 µg/mL) exhibit strong α-glucosidase inhibition. Likewise, the highest α-amylase inhibition was shown by crude extracts of Ficus religiosa (IC50 29.2 ± 1.2 µg/mL) and ethyl acetate fractions of Shorea robusta (IC50 69.3 ± 1.1 µg/mL), and the highest radical scavenging activity was shown by F. religiosa with an IC50 67.4 ± 0.6 µg/mL. Furthermore, to identify the metabolites within the fractions, we employed high-resolution mass spectrometry (LC-HRMS) and annotated 17 known metabolites which justify our assumption on activity. Of 4 medicinal plants examined, ethyl acetate fraction of S. robusta, ethyl acetate fraction of M. melabathrium, and water or ethyl acetate fraction of A. catechu extracts illustrated the best activities. With our study, we set up a foundation that provides authentic evidence to the community for use of these traditional plants. The annotated metabolites in this study support earlier experimental evidence towards the inhibition of enzymes. Further study is necessary to explore the clinical efficacy of these secondary molecules, which might be alternatives for the treatment of diabetes and pathogens.


2020 ◽  
Vol 2 (2) ◽  
pp. 16-21
Author(s):  
Reh Malem Br Karo ◽  
Putranto Manalu ◽  
Jhon Patar Sinurat

Natural products can be used as an alternative in the treatment of various diseases such as infectious diseases due to the bioactive compounds contained therein. Moreover nowdays, there are many antibiotic resistance in the treatment of infectious diseases. Citrus maxima is one of the natural products. Citrus maxima have been used for many diseases in traditional medicine.The aim of this study was to investigate the antibacterial activity of flavonoid-rich fractions of citrus maxima peel extract. The bioactive compounds contained in  Citrus maxima peel were extracted by maceration method using 96% ethanol solvent. Fractionation was conducted using liquid-liquid extraction using a solvent of water and ethyl acetate obtained ethyl acetate fraction. In this fraction, the TLC test was carried out to confirm the presence of phenolic and flavonoid compounds. The antibacterial activity testing for ethyl acetate fraction  against S.aureus and E.coli was determined  by disk diffusion method with concentration of 25 ppm, 50 ppm, 75 ppm and 100 ppm. The ciprofloxacin and distilled water were used as positive and negative control, respectively. The result of this study showed that ethyl acetate fraction ( flavonoid-rich fractions) Of Citrus Maxima has potential as antibacterial for bacterial S.aureus and E.coli with medium inhibitory ability in all of concentration ranges. The highest inhibition zone for S.aureus  was found  at a concentration of 100 ppm while for E.coli was at a concentration of 75 ppm.


Author(s):  
JHINUK BASU MULLICK ◽  
TAPAN MAJUMDAR ◽  
KUDUMULA VENKATA RAMI REDDY ◽  
SUMITA MUKHERJEE ◽  
SAMIR KUMAR SIL

Objective: The objective of this study was to look into the in vitro activity of Parkia javanica against isolates of Neisseria gonorrhoeae. Methods: Methanolic extract of P. javanica bark (MEPJ) and organic fractionation were tested against one standard strain and 10 clinical isolates including one multidrug-resistant (MDR) isolate of N. gonorrhoeae through minimum inhibitory concentrations (MIC) and minimum bactericidal concentrations (MBC) tests. Results: The MDR isolate, standard strain, as well as all the clinical isolates were inhibited by MEPJ as well as all the fractions except water fraction. Chloroform fraction showed the best activity with MIC and MBC values, both being 0.2 mg/ml. Ethyl acetate fraction also showed MIC value at 0.2 mg/ml; however, MBC value was at 0.3 mg/ml. MIC and MBC values of MEPJ were both 0.3 mg/ml. Conclusion: Chloroform fraction, ethyl acetate fraction, and MEPJ bark showed the lowest MIC values and can be considered as prospective candidates for the development of antigonococcal topical drugs.


2021 ◽  
Vol 1 (2) ◽  
pp. 20-27
Author(s):  
Jeremiah John Oloche ◽  
◽  
Bolaji Bosede Oluremi ◽  
Temiloluwa Oyindamola Koya

Global health is under constant threat due to antimicrobial drug resistance. Bacterial Infections caused by Pseudomonas aeruginosa are of importance because of their antibiotics resistance. This study aimed at evaluating the effects of extracts of Xylopia aethiopica (XA) on multidrug-resistant (MDR) Pseudomonas isolates. Fresh samples of XA leaf, stem bark and roots were collected from the botanical garden, University of Ibadan, Nigeria. Dried and pulverized samples were extracted with methanol and partitioned into n-hexane, dichloromethane and ethyl acetate. Phytochemical screening of the extracts was performed by standard methods. Antimicrobial activity and synergistic interaction were determined using microdilution and checkerboard broth dilution methods, respectively. The results revealed that crude methanol extracts of XA leaf, stem bark and root significantly (p<0.05) inhibited the growth of all tested MDR Pseudomonas isolates at 10 mg/mL. At 1 mg/mL, the ethyl acetate fraction of the leaf, and dichloromethane fraction of the roots produced clear zones of inhibition of 12 – 20 mm, and minimum inhibitory concentrations (MICs) of 1 µg/mL and 0.5 mg/mL, respectively. The modulation factor (MF) of ciprofloxacin, dichloromethane fraction of XA roots and ethyl acetate fraction of XA leaf were 4, 8, and 4 on MDR isolates E01006, OAU058 and P. aeruginosa ATCC 27853, respectively. In all tested isolates, but not E01006 and E01024, the fractional MICs of ciprofloxacin/ethylacetate fraction of XA leaf extract combination was not significantly different (p>0.05) compared with ciprofloxacin/verapamil combination. In conclusion, the root and leaf fractions Xylopia aethiopica that demonstrated antimicrobial activity against MDR P. aeruginosa and synergised with ciprofloxacin have the potential to rejuvenate the antimicrobial activity of ciprofloxacin in MDR P. aeruginosa.


2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Pakorn Aiewsakun ◽  
Pinidphon Prombutara ◽  
Tegar Adriansyah Putra Siregar ◽  
Thanida Laopanupong ◽  
Phongthon Kanjanasirirat ◽  
...  

AbstractTuberculosis is a global public health problem with emergence of multidrug-resistant infections. Previous epidemiological studies of tuberculosis in Thailand have identified a clonal outbreak multidrug-resistant strain of Mycobacterium tuberculosis in the Kanchanaburi province, designated “MKR superspreader”, and this particular strain later was found to also spread to other regions. In this study, we elucidated its biology through RNA-Seq analyses and identified a set of genes involved in cholesterol degradation to be up-regulated in the MKR during the macrophage cell infection, but not in the H37Rv reference strain. We also found that the bacterium up-regulated genes associated with the ESX-1 secretion system during its intracellular growth phase, while the H37Rv did not. All results were confirmed by qRT-PCR. Moreover, we showed that compounds previously shown to inhibit the mycobacterial ESX-1 secretion system and cholesterol utilisation, and FDA-approved drugs known to interfere with the host cholesterol transportation were able to decrease the intracellular survival of the MKR when compared to the untreated control, while not that of the H37Rv. Altogether, our findings suggested that such pathways are important for the MKR’s intracellular growth, and potentially could be targets for the discovery of new drugs against this emerging multidrug-resistant strain of M. tuberculosis.


2021 ◽  
Author(s):  
Alex B. Green ◽  
Katelyn E. Zulauf ◽  
Katherine A. Truelson ◽  
Lucius Chiaraviglio ◽  
Meng Cui ◽  
...  

AbstractPathogen inactivation is a strategy to improve the safety of transfusion products. The Cerus Intercept technology makes use of a psoralen compound called amotosalen in combination with UVA light to inactivate bacteria, viruses and protozoa. Psoralens have structural similarity to bacterial multidrug-efflux pump substrates. As these efflux pumps are often overexpressed in multidrug-resistant pathogens and with recent reported outbreaks of transfusion-associated sepsis with Acinetobacter, we tested whether contemporary drug-resistant pathogens might show resistance to amotosalen and other psoralens based on multidrug efflux mechanisms through microbiological, biophysical and molecular modeling analysis. The main efflux systems in Enterobacterales and Acinetobacter baumannii, tripartite RND (resistance-nodulation-cell division) systems which span the inner and outer membranes of Gram-negative pathogens and expel antibiotics from the bacterial cytoplasm into the extracellular space, were specifically examined. We found that amotosalen was an efflux substrate for the TolC-dependent RND efflux pumps in E. coli and the AdeABC efflux pump from Acinetobacter baumannii, and that minimal inhibitory concentrations for contemporary bacterial isolates in vitro approached and exceeded the concentration of amotosalen used in the approved platelet and plasma inactivation procedures. These findings suggest that otherwise safe and effective inactivation methods should be further studied to exclude possible gaps in their ability to inactivate contemporary, multidrug-resistant bacterial pathogens.ImportancePathogen inactivation is a strategy to enhance the safety of transfused blood products. We identify the compound, amotosalen, widely used for pathogen inactivation, as a bacterial multidrug efflux substrate. Specifically, experiments suggest that amotosalen is pumped out of bacteria by the major TolC-dependent RND efflux pumps in E. coli and the AdeABC efflux pump in Acinetobacter baumannii. Such efflux pumps are often overexpressed in multidrug-resistant pathogens. Importantly, the minimal inhibitory concentrations for contemporary multidrug-resistant Enterobacterales, Acinetobacter baumannii, Pseudomonas aeruginosa, Burkholderia spp., and Stenotrophomonas maltophilia isolates approached or exceeded the amotosalen concentration used in approved platelet and plasma inactivation procedures, potentially as a result of efflux pump activity. Although there are important differences in methodology between our experiments and blood product pathogen inactivation, these findings suggest that otherwise safe and effective inactivation methods should be further studied to exclude possible gaps in their ability to inactivate contemporary, multidrug-resistant bacterial pathogens.


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