scholarly journals Antibacterial Activity of Chalcone and Dihydrochalcone Compounds from Uvaria chamae Roots against Multidrug-Resistant Bacteria

2018 ◽  
Vol 2018 ◽  
pp. 1-10 ◽  
Author(s):  
H. Koudokpon ◽  
N. Armstrong ◽  
T. V. Dougnon ◽  
L. Fah ◽  
E. Hounsa ◽  
...  

This study presents antimicrobial properties of Uvaria chamae roots, commonly used for the treatment of various infections in south Benin. Their constituents were extracted and then fractionated in order to isolate the active ingredients. Antimicrobial susceptibility tests were performed against several multidrug-resistant bacteria using the Mueller Hilton well agar diffusion method. Results showed that ethanol extracts were highly active against Gram-positive cocci. This activity was more extensive than that measured from conventional broad-spectrum antibiotics. Indeed, vancomycin-resistant enterococcus (VRE) and methicillin-resistant Staphylococcus aureus (MRSA) strains were all sensitive to this root extract. The aim of this study was to link the antimicrobial activity of the root to chemical structures. The ion mobility mass spectrometry analysis revealed for the first time the presence of ten chalcone and dihydrochalcone structures responsible for the antimicrobial activity of Uvaria chamae ethanol extracts. Two structures were described here for the first time in these roots. These findings confirm and justify the medical properties of these roots used as a traditional medicine.

Author(s):  
Amita Shobha Rao ◽  
Shobha Kl ◽  
Prathibha Md’almeida ◽  
Kiranmai S Rai

  Objective: Infections caused by Gram-negative bacteria are important causes of morbidity and mortality. Extracts of plants and herbs such as Clitorea ternatea are used as diuretic. This work attempts to find out antimicrobial activity of aqueous and alcoholic extract of C. ternatea roots against Pseudomonas aeruginosa (ATCC 27853), Escherichia coli (ATCC 25922), clinical strains of Klebsiella pneumoniae, and Candida albicans.Methods: The agar well-diffusion method was done using Mueller Hinton agar and Sabouraud’s dextrose agar. The microorganism grown in peptone water was inoculated into culture medium. 4 mm diameter well punched into the agar was filled with 20 μl of aqueous and alcoholic root extracts C. ternatea extracts in various concentrations (100-25 μg/ml). The plates were incubated and antimicrobial activity was evaluated.Results: Aqueous root extract of C. ternatea with the concentration of 100 μg/ml showed zone of inhibition against E. coli (ATCC 25922) 18 mm, P. aeruginosa (ATCC 27853) 14 mm, multidrug resistant strain of K. pneumoniae 15 mm. Alcoholic extract of C. ternatea with the concentration of 100 μg/ml showed zone of inhibition of 35 mm against E. coli (ATCC 25922), P. aeruginosa (ATCC 27853) 22 mm, and multidrug resistant strain of K. pneumoniae 28 mm. C. albicanswas resistant to both extract of C. ternatea root. Conclusions: Alcoholic extract of C. ternatea is a better antibacterial agent against multidrug resistant Klebsiella species and other Gram-negative pathogens. Further, studies are required to identify active substances from the alcoholic extracts of C. ternatea for treating infections.


2020 ◽  
Vol 149 ◽  
pp. 104529
Author(s):  
Jorge Belém Oliveira-Júnior ◽  
Everton Morais da Silva ◽  
Dyana Leal Veras ◽  
Karla Raíza Cardoso Ribeiro ◽  
Catarina Fernandes de Freitas ◽  
...  

2007 ◽  
Vol 38 (4) ◽  
pp. 704-709 ◽  
Author(s):  
Paulo André Vicente Fernandes ◽  
Isabel Renata de Arruda ◽  
Antônio Fernando Amatto Botelho dos Santos ◽  
Ana Albertina de Araújo ◽  
Ana Maria Souto Maior ◽  
...  

2017 ◽  
Vol 66 (2) ◽  
pp. 171-180 ◽  
Author(s):  
Fevronia Kolonitsiou ◽  
Matthaios Papadimitriou-Olivgeris ◽  
Anastasia Spiliopoulou ◽  
Vasiliki Stamouli ◽  
Vasileios Papakostas ◽  
...  

The aim of the study was to assess the epidemiology, the incidence of multidrug-resistant bacteria and bloodstream infections’ (BSIs) seasonality in a university hospital. This retrospective study was carried out in the University General Hospital of Patras, Greece, during 2011–13 y. Blood cultures from patients with clinical presentation suggestive of bloodstream infection were performed by the BacT/ALERT System. Isolates were identified by Vitek 2 Advanced Expert System. Antibiotic susceptibility testing was performed by the disk diffusion method and E-test. Resistance genes (mecA in staphylococci; vanA/vanB/vanC in enterococci; blaKPC/blaVIM/blaNDM in Klebsiella spp.) were detected by PCR. In total, 4607 (9.7%) blood cultures were positive from 47451 sets sent to Department of Microbiology, representing 1732 BSIs. Gram-negative bacteria (52.3%) were the most commonly isolated, followed by Gram-positive (39.5%), fungi (6.6%) and anaerobes bacteria (1.8%). The highest contamination rate was observed among Gram-positive bacteria (42.3%). Among 330 CNS and 150 Staphylococcus aureus, 281 (85.2%) and 60 (40.0%) were mecA-positive, respectively. From 113 enterococci, eight were vanA, two vanB and two vanC-positives. Of the total 207 carbapenem-resistant Klebsiella pneumoniae (73.4%), 202 carried blaKPC, four blaKPC and blaVIM and one blaVIM. A significant increase in monthly BSIs’ incidence was shown (R2: 0.449), which may be attributed to a rise of Gram-positive BSIs (R2: 0.337). Gram-positive BSIs were less frequent in spring (P < 0.001), summer (P < 0.001), and autumn (P < 0.001), as compared to winter months, while Gram-negative bacteria (P < 0.001) and fungi (P < 0.001) were more frequent in summer months. BSIs due to methicillin resistant S. aureus and carbapenem-resistant Gram-negative bacteria increased during the study period. The increasing incidence of BSIs can be attributed to an increase of Gram-positive BSI incidence, even though Gram-negative bacteria remained the predominant ones. Seasonality may play a role in the predominance of Gram-negative’s BSI.


Diagnostics ◽  
2021 ◽  
Vol 11 (9) ◽  
pp. 1617
Author(s):  
Raouaa Maaroufi ◽  
Olfa Dziri ◽  
Linda Hadjadj ◽  
Seydina M. Diene ◽  
Jean-Marc Rolain ◽  
...  

Hospital environments constitute the main reservoir of multidrug-resistant bacteria. In this study we aimed to investigate the presence of Gram-negative bacteria in one Northwestern Tunisian hospital environment, and characterize the genes involved in bacterial resistance. A total of 152 environmental isolates were collected from various surfaces and isolated using MacConkey medium supplemented with cefotaxime or imipenem, with 81 fermenter bacteria (27 Escherichia coli, and 54 Enterobacter spp., including 46 Enterobacter cloacae), and 71 non-fermenting bacteria (69 Pseudomonas spp., including 54 Pseudomonas aeruginosa, and 2 Stenotrophomonas maltophilia) being identified by the MALDI-TOF-MS method. Antibiotic susceptibility testing was performed by disk diffusion method and E-Test was used to determine MICs for imipenem. Several genes implicated in beta-lactams resistance were characterized by PCR and sequencing. Carbapenem resistance was detected among 12 isolates; nine E. coli (blaNDM-1 (n = 8); blaNDM-1 + blaVIM-2 (n = 1)) and three P. aeruginosa were carbapenem-resistant by loss of OprD porin. The whole-genome sequencing of P. aeruginosa 97H was determined using Illumina MiSeq sequencer, typed ST285, and harbored blaOXA-494. Other genes were also detected, notably blaTEM (n = 23), blaCTX-M-1 (n = 10) and blaCTX-M-9 (n = 6). These new epidemiological data imposed new surveillance strategies and strict hygiene rules to decrease the spread of multidrug-resistant bacteria in this area.


2021 ◽  
Author(s):  
Riju Maharjan ◽  
Anup Bastola ◽  
Nabaraj Adhikari ◽  
Komal Raj Rijal ◽  
Megha Raj Banjara ◽  
...  

Abstract Background Bacterial opportunistic infections are quite common in HIV patients. Besides HIV-TB coinfection, lower respiratory tract infections by multidrug-resistant bacteria cause significant morbidity and mortality among HIV patients. This study was done to evaluate the bacterial coinfection of LRT and detect plasmid-mediated blaTEM and blaCTX−M genes among Extended-Spectrum β-Lactamase (ESBL) producing isolates from sputum samples in HIV patients. Methods A total of 263 sputum samples from HIV-positive cases were processed with standard microbiological methods to isolate and identify the possible pathogens. The identified bacterial isolates were assessed for antibiotic susceptibility pattern by using modified Kirby Bauer disk diffusion method following Clinical Laboratory Standard Institute (CLSI) guidelines. Plasmid DNA was extracted from multidrug-resistant and ESBL producers for screening of ESBL genes; blaCTX−M and blaTEM by conventional PCR method using specific primers. Results Of 263 sputum samples, 67 (25.48%) were culture positive showing Klebsiella pneumoniae; 17(25.37%) as the most predominant one. A higher rate of infection (4/8, 50%) was observed among old-aged people of 61 -70 years, whereas no infection was observed below 20 years. About 30.0% (15/50) of smokers, 32.86% (23/70) cases with previous pulmonary tuberculosis and 52.38% (11/21) with CD4 count <200 cells/µl were found to be susceptible to LRTIs. Among 53 bacterial isolates, 52.83% (n=28) were multidrug-resistant and 43.4% (n=23) were ESBL producers. All ESBL producers were sensitive to Colistin and Polymyxin B. Of 23 ESBL producers, 47.83% (11/23) and 8.6% (2/23) possessed only blaCTX−M and blaTEM genes respectively and 43.48% (10/23) possessed both ESBL genes. Conclusion The increasing rate of MDR bacterial infections mainly ESBL producers of LRTIs causes difficulty in the management of diseases leading to high morbidity and mortality of HIV patients.


2014 ◽  
Vol 20 ◽  
pp. 41-48
Author(s):  
MM Akhtar ◽  
MS Islam ◽  
MF Begum ◽  
M Anisuzzaman ◽  
MF Alam

Context: Emergence of multi drug resistance bacteria (MDRB) to human pathogenic infection is increasing day by day but the number of new drugs to overwhelm the problem is not sufficient. Evidences revealed that Moringa oleifera Lamk. has various pharmaceutical activities like antibacterial, antifungal, antispasmodic, anti-inflammatory, anticancer and diuretic. Herbal treatment may be one of the possible ways to treat diseases caused by multidrug-resistant bacteria. Objectives: The present research was undertaken to screen of multidrug resistant bacteria (MDRB) from antibiotic-associated diarrheal samples and to evaluate the potentiality of M. oleifera leaf extracts on these bacteria with the view to provide scientific evidence for its application in health remedy. Materials & Methods: Antibiotic-associated diarrheal fecal specimens were collected from pediatric ward of Rajshahi Medical College and cultured onto MacConkey agar. MDRB were determined by antibiotic susceptibility test, using disc-agar diffusion method. Biochemical tests of the MDRB were done according to Bergey’s Manual of Determinative Bacteriology for identification of the species. Dried and fresh leaf of M. oleifera was used to prepare exaction with or without solvents such as hot water, cold water, chloroform, petroleum ether, acetone and ethanol, separately. Antibacterial assay was done by disc diffusion method and minimum inhibitory concentration of the extracts was also measured. Results: In the present study seven isolates were screened as MDRB and the highest prevalence (42.86%) was occurred in the age group of 25-36 months and the lowest (14.28) was in the group of <1 and 1-6 months. Ethanol extract of dried leaf of M. oleifera Lamk. showed moderate inhibitory activity against all of the isolates while petroleum ether, chloroform and acetone extracts of dried leaf have no inhibitory effect. Fresh leaf sap powder in DMSO exhibited strong inhibitory effect against all of the test bacteria where as hot aqueous extract could not show any inhibition. The minimum inhibitory concentrations (MIC) of the potent extracts ranged 937.5 to 3750 ?g/ml and 7.9 to 234.4 ?g/ml in dried and fresh leaf extracts, respectively. Conclusion: The present data indicates that M. oleifera leaf extract possess antimicrobial potential to control of MDRB causes infection thus it can be used as a novel drugs in future. DOI: http://dx.doi.org/10.3329/jbs.v20i0.17652 J. bio-sci. 20: 41-48, 2012


2015 ◽  
Vol 2015 ◽  
pp. 1-20 ◽  
Author(s):  
M. F. Elkady ◽  
H. Shokry Hassan ◽  
Elsayed E. Hafez ◽  
Ahmed Fouad

Nano-ZnO has been successfully implemented in particles, rods, and tubes nanostructures via sol-gel and hydrothermal techniques. The variation of the different preparation parameters such as reaction temperature, time, and stabilizer agents was optimized to attain different morphological structures. The influence of the microwave annealing process on ZnO crystallinity, surface area, and morphological structure was monitored using XRD, BET, and SEM techniques, respectively. The antimicrobial activity of zinc oxide produced in nanotubes structure was examined against four different multidrug resistant bacteria: Gram-positive (Staphylococcus aureusandBacillus subtilis) and Gram-negative (Escherichia coliandPseudomonas aeruginosa) strains. The activity of produced nano-ZnO was determined by disc diffusion technique and the results revealed that ZnO nanotubes recorded high activity against the studied strains due to their high surface area equivalent to 17.8 m2/g. The minimum inhibitory concentration (MIC) of ZnO nanotubes showed that the low concentrations of ZnO nanotubes could be a substitution for the commercial antibiotics when approached in suitable formula. Although the annealing process of ZnO improves the degree of material crystallinity, however, it declines its surface area and consequently its antimicrobial activity.


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