Antimicrobial activity of seven Piper species from Colombian coffee-growing Eco-region against multidrug resistant bacteria

2020 ◽  
Vol 3 (3) ◽  
pp. 33-37
Author(s):  
Oscar M Mosquera ◽  
◽  
Roman Y. Ramirez-Rueda ◽  
Aura M. Blandon ◽  
◽  
...  

Species of Piper genus are known for their numerous biological activities and their diverse phytochemical composition. The object of this work was to evaluate the antibacterial activity of extracts obtained from seven Piperaceae species. Broth microdilution technique was used for biological evaluation and some phytochemical nuclei present in the bioactive extracts were identified by thin layer chromatography and characterization reactions. Among the most important results, it is highlighted the inhibitory effect of the methanolic extract from Piper pesaresanum against Methicillin-resistant Staphylococcus aureus ATTC 43300, with minimum inhibitory concentration of 62.5 μg/mL. Additionally, secondary metabolites such as alkaloids, phenols and flavonoids were detected in this extract. In conclussion, the species P. pesaresanum showed high potential for bioguided search of antibacterial compounds against multidrug resistant S. aureus.

Fluids ◽  
2020 ◽  
Vol 5 (2) ◽  
pp. 76 ◽  
Author(s):  
Raquel Portela ◽  
Filipe Valcovo ◽  
Pedro L. Almeida ◽  
Rita G. Sobral ◽  
Catarina R. Leal

Multidrug resistant bacteria are one of the most serious public health threats nowadays. How bacteria, as a population, react to the presence of antibiotics is of major importance to the outcome of the chosen treatment. In this study we addressed the impact of oxacillin, a β-lactam, the most clinically relevant class of antibiotics, in the viscosity profile of the methicillin resistant Staphylococcus aureus (MRSA) strain COL. In the first approach, the antibiotic was added, at concentrations under the minimum inhibitory concentration (sub-MIC), to the culture of S. aureus and steady-state shear flow curves were obtained for discrete time points during the bacterial growth, with and without the presence of the antibiotic, showing distinct viscosity progress over time. The different behaviors obtained led us to test the impact of the sub-inhibitory concentration and a concentration that inhibited growth. In the second approach, the viscosity growth curves were measured at a constant shear rate of 10 s−1, over time. The obtained rheological behaviors revealed distinctive characteristics associated to the presence of each concentration of the tested antibiotic. These results bring new insights to the bacteria response to a well-known bacteriolytic antibiotic.


2020 ◽  
Vol 21 (10) ◽  
pp. 997-1004
Author(s):  
Leila Azimi ◽  
Sahel V. Tahbaz ◽  
Reza Alaghehbandan ◽  
Farank Alinejad ◽  
Abdolaziz R. Lari

Background: Burn is still an important global public health challenge. Wound colonization of antibiotic resistant bacteria such as Acinetobacter baumannii can lead to high morbidity and mortality in burn patients. The aim of this study was to evaluate the inhibitory effect of tazobactam on efflux pump, which can cause aminoglycoside resistant in A. baumannii isolated from burn patients. Methods: In this study, 47 aminoglycoside resistant A. baumannii spp. were obtained from burn patients, admitted to the Shahid Motahari Burns Hospital in Tehran, Iran, during June-August 2018. The inhibitory effect of tazobactam against adeB such as efflux pump was evaluated by Minimum Inhibitory Concentration (MIC) determination of amikacin alone and in combination with tazobactam. Fractional Inhibitory Concentration index (FIC) was used to determine the efficacy of tazobactam/ amikacin combination. Further, semi-quantitative Real- Time PCR was performed to quantify the expression rates of the adeB gene before and after addition of tazobactam/amikacin. Results: The MIC values were significantly reduced when a combined amikacin and tazobactam was utilized. The most common interaction observed was synergistic (78.2%), followed by additive effects (21.8%), as per FIC results. The adeB mRNA expression levels were found to be downregulated in 60.7% of isolates treated with tazobactam. Conclusions: Tazobactam can have impact on resistance to aminoglycoside by inhibiting efflux pump. Thus, the combination of tazobactam with amikacin can be used as an alternative treatment approach in multidrug resistant A. baumannii infections.


Antibiotics ◽  
2021 ◽  
Vol 10 (6) ◽  
pp. 678
Author(s):  
Abdallah S. Abdelsattar ◽  
Rana Nofal ◽  
Salsabil Makky ◽  
Anan Safwat ◽  
Amera Taha ◽  
...  

The emergence and evolution of antibiotic-resistant bacteria is considered a public health concern. Salmonella is one of the most common pathogens that cause high mortality and morbidity rates in humans, animals, and poultry annually. In this work, we developed a combination of silver nanoparticles (AgNPs) with bacteriophage (phage) as an antimicrobial agent to control microbial growth. The synthesized AgNPs with propolis were characterized by testing their color change from transparent to deep brown by transmission electron microscopy (TEM) and Fourier-Transform Infrared Spectroscopy (FTIR). The phage ZCSE2 was found to be stable when combined with AgNPs. Both minimum inhibitory concentration (MIC) and minimum bactericidal concentration (MBC) were evaluated for AgNPs, phage, and their combination. The results indicated that MIC and MBC values were equal to 23 µg/mL against Salmonella bacteria at a concentration of 107 CFU/mL. The combination of 0.4× MIC from AgNPs and phage with Multiplicity of Infection (MOI) 0.1 showed an inhibitory effect. This combination of AgNPs and phage offers a prospect of nanoparticles with significantly enhanced antibacterial properties and therapeutic performance.


2019 ◽  
Vol 20 (4) ◽  
pp. 956-964 ◽  
Author(s):  
DIAH AYUNINGRUM ◽  
RHESI KRISTIANA ◽  
AYUNDA AINUN NISA ◽  
SEPTHY KUSUMA RADJASA ◽  
SAKTI IMAM MUCHLISSIN ◽  
...  

Abstract. Ayuningrum D, Kristiana R, Nisa AA, Radjasa SK, Muchlissin SI, Radjasa OK, Sabdono A, Trianto A. 2019. Bacteria associated with tunicate, Polycarpa aurata, from Lease Sea, Maluku, Indonesia exhibiting anti-multidrug resistant bacteria. Biodiversitas 20: 956-964. Tunicate is a rich secondary metabolites producer with various biological activities whether as an original producer or produced by the associated microorganisms. In this study, a total of 11 tunicate specimens were identified as Polycarpa aurata with four color variations based on morphological characteristic and COI gene identification and BLAST analysis. The P. aurata associated-bacteria were isolated and tested for antimicrobial activity against multi-drug resistant (MDR) bacteria. A total of 86 axenic isolates were successfully purified. Furthermore, nine isolates (10.5%) exhibited antibacterial activity on preliminary screening. Nine prospective isolates were fermented in respective medium (Zobell 2216, modified M1 or modified ISP2 media) then extracted using ethyl acetate. The ethyl acetate extracts from liquid fermentation were tested against MDR Escherichia coli, MDR Bacillus cereus, Methicillin-Resistant Staphylococcus aureus (MRSA) and Methicillin-Sensitive and Staphylococcus aureus (MSSA). As a result, seven isolates (8.1%) still retained the activity at the extract concentration 150 µg/disk. Molecular analysis based on 16S rDNA sequencing revealed the most active isolates, TSB 47, TSC 10 and TSB 34 identified as Bacillus tropicus, Vibrio alginolyticus and Virgibacillus massiliensis, with BLAST homology 99%.


Author(s):  
Yucheng Cao ◽  
Kaiyi Wang ◽  
Jiali Wang ◽  
Haoran Cheng ◽  
Mengxin Ma ◽  
...  

Aim: With the increasing abuse of antibacterial drugs, multidrug-resistant bacteria have become a burden on human health and the healthcare system. To find alternative compounds effective against hospital-acquired methicillin-resistant Staphylococcus aureus (HA-MRSA), novel derivatives of ocotillol were synthesized. Methods & Results: Ocotillol derivatives with polycyclic nitrogen-containing groups were synthesized and evaluated for in vitro antibacterial activity. Compounds 36–39 exhibited potent antibacterial activity against hospital-acquired MRSA, with MIC = 8–64 μg/ml. Additionally, a combination of compound 37 and the commercially available antibiotic kanamycin showed synergistic inhibitory effects, with a fractional inhibitory concentration index of ≤0.375. Conclusion: Compound 37 has a strong inhibitory effect, and this derivative has potential for use as a pharmacological tool to explore antibacterial mechanisms.


Plants ◽  
2019 ◽  
Vol 9 (1) ◽  
pp. 47 ◽  
Author(s):  
Phuong-Y Mai ◽  
Marceau Levasseur ◽  
Didier Buisson ◽  
David Touboul ◽  
Véronique Eparvier

The emergence of multidrug resistant bacterial pathogens and the increase of antimicrobial resistance constitutes a major health challenge, leading to intense research efforts being focused on the discovery of novel antimicrobial compounds. In this study, endophytes were isolated from different parts of Sandwithia guyanensis plant (leaves, wood and latex) belonging to the Euphorbiaceae family and known to produce antimicrobial compounds, and chemically characterised using Molecular Network in order to discover novel antimicrobial molecules. One fungal endophyte extract obtained from S. guyanensis latex showed significant antimicrobial activity with Minimal Inhibitory Concentration on methicillin-resistant Staphylococcus aureus at 16 µg/mL. The chemical investigation of this fungus (Lecanicillium genus) extract led to the isolation of 5 stephensiolides compounds, four of which demonstrated antibacterial activity. Stephensiolide I and G showed the highest antibacterial activity on MRSA with a MIC at 4 and 16 µg/mL respectively.


2020 ◽  
Vol 12 (19) ◽  
pp. 1709-1727 ◽  
Author(s):  
Yuan-Yuan Hu ◽  
Juan Wang ◽  
Tie-Jun Li ◽  
Rammohan R Yadav Bheemanaboina ◽  
Mohammad Fawad Ansari ◽  
...  

Aim: With the increasing emergence of drug-resistant bacteria, the need for new antimicrobial agents has become extremely urgent. This work was to develop sulfonyl thiazoles as potential antibacterial agents. Results & methodology: Novel hybrids of sulfonyl thiazoles were developed from commercial acetanilide and acetylthiazole. Hybrids 6e and 6f displayed excellent inhibitory efficacy against clinical methicillin-resistant Staphylococcus aureus (MRSA) (minimum inhibitory concentration = 1 μg/ml) without obvious toxicity toward normal mammalian cells (RAW 264.7). The combination uses were found to improve the antimicrobial ability. Further preliminary antibacterial mechanism experiments showed that the active molecule 6f could effectively interfere with MRSA membrane and insert into MRSA DNA. Conclusion: Compounds 6e and 6f could serve as potential DNA-targeting templates toward the development of promising antimicrobial agents.


Antibiotics ◽  
2020 ◽  
Vol 9 (7) ◽  
pp. 367
Author(s):  
Alexandre Lamas ◽  
Vicente Arteaga ◽  
Patricia Regal ◽  
Beatriz Vázquez ◽  
José Manuel Miranda ◽  
...  

Antimicrobial resistance is one of today’s major public health challenges. Infections caused by multidrug-resistant bacteria have been responsible for an increasing number of deaths in recent decades. These resistant bacteria are also a concern in the food chain, as bacteria can resist common biocides used in the food industry and reach consumers. As a consequence, the search for alternatives to common antimicrobials by the scientific community has intensified. Substances obtained from nature have shown great potential as new sources of antimicrobial activity. The aim of this study was to evaluate the antimicrobial activity of five bee venoms, also called apitoxins, against two common foodborne pathogens. A total of 50 strains of the Gram-negative pathogen Salmonella enterica and 8 strains of the Gram-positive pathogen Listeria monocytogenes were tested. The results show that the minimum inhibitory concentration (MIC) values were highly influenced by the bacterial genus. The MIC values ranged from 256 to 1024 µg/mL in S. enterica and from 16 to 32 µg/mL in L. monocytogenes. The results of this study demonstrate that apitoxin is a potential alternative agent against common foodborne pathogens, and it can be included in the development of new models to inhibit the growth of pathogenic bacteria in the food chain.


2020 ◽  
Vol 8 (10) ◽  
pp. 1487
Author(s):  
Marta Aires-de-Sousa ◽  
Claudine Fournier ◽  
Elizeth Lopes ◽  
Hermínia de Lencastre ◽  
Patrice Nordmann ◽  
...  

In order to evaluate whether seagulls living on the Lisbon coastline, Portugal, might be colonized and consequently represent potential spreaders of multidrug-resistant bacteria, a total of 88 gull fecal samples were screened for detection of extended-spectrum β-lactamase (ESBL)- or carbapenemase-producing Enterobacteriaceae for methicillin-resistant Staphylococcus aureus (MRSA) and for vancomycin-resistant Enterococci (VRE). A large proportion of samples yielded carbapenemase- or ESBL-producing Enterobacteriaceae (16% and 55%, respectively), while only two MRSA and two VRE were detected. Mating-out assays followed by PCR and whole-plasmid sequencing allowed to identify carbapenemase and ESBL encoding genes. Among 24 carbapenemase-producing isolates, there were mainly Klebsiella pneumoniae (50%) and Escherichia coli (33%). OXA-181 was the most common carbapenemase identified (54%), followed by OXA-48 (25%) and KPC-2 (17%). Ten different ESBLs were found among 62 ESBL-producing isolates, mainly being CTX-M-type enzymes (87%). Co-occurrence in single samples of multiple ESBL- and carbapenemase producers belonging to different bacterial species was observed in some cases. Seagulls constitute an important source for spreading multidrug-resistant bacteria in the environment and their gut microbiota a formidable microenvironment for transfer of resistance genes within bacterial species.


2019 ◽  
Vol 20 (5) ◽  
pp. 1083 ◽  
Author(s):  
Seindé Touré ◽  
Sandy Desrat ◽  
Léonie Pellissier ◽  
Pierre-Marie Allard ◽  
Jean-Luc Wolfender ◽  
...  

A biological evaluation of a library of extracts from entomopathogen strains showed that Pantoea sp. extract has significant antimicrobial and insecticidal activities. Three hydroxyacyl-phenylalanine derivatives were isolated from this strain. Their structures were elucidated by a comprehensive analysis of their NMR and MS spectroscopic data. The antimicrobial and insecticidal potencies of these compounds were evaluated, and compound 3 showed 67% mortality against Aedes aegypti larvae at a concentration of 100 ppm, and a minimum inhibitory concentration (MIC) of 16 µg/mL against methicillin-resistant Staphylococcus aureus. Subsequently, hydroxyacyl-phenylalanine analogues were synthesized to better understand the structure-activity relationships within this class of compounds. Bioassays highlighted the antimicrobial potential of analogues containing saturated medium-chain fatty acids (12 or 14 carbons), whereas an unsaturated long-chain fatty acid (16 carbons) imparted larvicidal activity. Finally, using a molecular networking-based approach, several close analogues of the isolated and newly synthesized lipoamino acids were discovered in the Pantoea sp. extract.


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