scholarly journals Evaluation of antimicrobial and antibiofilm activities of stingless bee Trigona honey (Malaysia) against Streptococcus pneumoniae

10.3823/856 ◽  
2021 ◽  
Vol 11 (2) ◽  
Author(s):  
Mohammad A. Alkafaween ◽  
Hamid A. Nagi Al-Jamal ◽  
Abu Bakar Mohmd Hilmi
Keyword(s):  
Antibacterial Activity ◽  
Streptococcus Pneumoniae ◽  
Biofilm Formation ◽  
Stingless Bee ◽  
Expression Of Genes ◽  
Zones Of Inhibition

Background: The study aims to evaluate the antibacterial activity of Trigona honey against S. pneumonia. Methods: The effect of Trigona honey on S. pneumonia investigated using agar well diffusion, MIC, MBC, biofilm formation and RT-qPCR. Results: Trigona honey samples showed the larger zones of inhibition against S. pneumonia, 22.2±0.4 at 100% concentration. Trigona honey possessed the lowest MIC, MBC, MIC50 and MIC90 against S. pneumoniae, 25%, 30%, 12.5% and 25% (w/v) respectively. Trigona honey permeated established biofilms of S. pneumonia, resulting in significant decreased the cells from the biofilm. RT-qPCR revealed that the expression of genes amiF, ftsY, mvaS, pnpA, argG, mvd1, purN, miaA and pbp2a were upregulated, glcK, marR, prmA and ccpA­­­ were downregulated after exposure to honey. Conclusion: Trigona honey demonstrated the highest antibacterial activity against S. pneumoniae. By limiting study in vitro on Trigona honey, we infer that Trigona honey impacts on S. pneumoniae.

scholarly journals Antibacterial Activity of Locally Prepared Herbal Cough Extracts against Klebsiella pneumoniae and Streptococcus pneumoniae

2019 ◽  
pp. 1-9
Author(s):  
Atuheirwe Maxine ◽  
Jacob Stanley Iramiot
Keyword(s):  
Antibacterial Activity ◽  
Streptococcus Pneumoniae ◽  
Klebsiella Pneumoniae ◽  
Diffusion Method ◽  
Dilution Method ◽  
Herbal Extracts ◽  
Bacterial Strains ◽  
Zones Of Inhibition ◽  
Tract Infections

Aim: Cough due to Klebsiella pneumoniae and Streptococcus pneumoniae is currently managed by conventional antibiotics and herbal extracts in Uganda. However, much as these herbal extracts are extensively used, their antibacterial activity is not known. This study aimed at determining the antibacterial activity of the selected locally prepared herbal cough extracts against two bacterial strains i.e. Klebsiella pneumoniae (ATCC 700603), and Streptococcus pneumoniae (ATCC 49619). Methods: The herbal cough extracts were screened for antibacterial activity using Agar-well diffusion method for determining zone of inhibition, macro broth dilution method for Minimum Inhibitory Concentration (MIC) determination and Streak plate method for Minimum Bactericidal Concentration (MBC). Results: In vitro evaluation of antibacterial activity of the 5 brands of herbal cough extracts against K. pneumoniae and S. pneumoniae   revealed that all extracts possessed significant antimicrobial effects against all microorganisms tested (p < 0.05). However, MM04 (35.6±0.0) mm and MM03 (33.6±1.5) mm had maximum zones of inhibition as compared to other herbal extracts against K. pneumoniae and S. pneumoniae respectively. Average MIC results for extracts against K. pneumoniae   indicated that MM01 had the highest MIC (2.5000 mg/ml) while MM03 had the least MIC (0.0625 mg/ml). Average MIC results for extracts against S. pneumoniae showed MM01 had the highest MIC (2.0000 mg/ml) while MM03 3 had the least MIC (0.0438 mg/ml). Average MBC results for extracts against K. pneumoniae indicated that MM01 had the highest MBC (4.000 mg/ml) while MM03 had the least MBC (0.030 mg/ml). Average MBC results for extracts against S. pneumoniae showed MM01 had the highest MBC (4.000 mg/ml) while MM03 had the least MBC (0.033 mg/ml). Conclusion: The results obtained in present study were revealed that locally prepared herbal extracts had significant antibacterial activity. Hence they can be used as promising alternatives of antibiotics used against Respiratory Tract Infections due to K. pneumoniae and S. pneumoniae.

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 Antibiofilm and antivirulence potential of silver nanoparticles against multidrug-resistant Acinetobacter baumannii

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Helal F. Hetta ◽  
Israa M. S. Al-Kadmy ◽  
Saba Saadoon Khazaal ◽  
Suhad Abbas ◽  
Ahmed Suhail ◽  
...  
Keyword(s):  
Silver Nanoparticles ◽  
Antibacterial Activity ◽  
Acinetobacter Baumannii ◽  
Biofilm Formation ◽  
Microtiter Plate ◽  
Diffusion Method ◽  
Resistance Pattern ◽  
Infection Model ◽  
The Impact

AbstractWe aimed to isolate Acinetobacter baumannii (A. baumannii) from wound infections, determine their resistance and virulence profile, and assess the impact of Silver nanoparticles (AgNPs) on the bacterial growth, virulence and biofilm-related gene expression. AgNPs were synthesized and characterized using TEM, XRD and FTIR spectroscopy. A. baumannii (n = 200) were isolated and identified. Resistance pattern was determined and virulence genes (afa/draBC, cnf1, cnf2, csgA, cvaC, fimH, fyuA, ibeA, iutA, kpsMT II, PAI, papC, PapG II, III, sfa/focDE and traT) were screened using PCR. Biofilm formation was evaluated using Microtiter plate method. Then, the antimicrobial activity of AgNPs was evaluated by the well-diffusion method, growth kinetics and MIC determination. Inhibition of biofilm formation and the ability to disperse biofilms in exposure to AgNPs were evaluated. The effect of AgNPs on the expression of virulence and biofilm-related genes (bap, OmpA, abaI, csuA/B, A1S_2091, A1S_1510, A1S_0690, A1S_0114) were estimated using QRT-PCR. In vitro infection model for analyzing the antibacterial activity of AgNPs was done using a co-culture infection model of A. baumannii with human fibroblast skin cell line HFF-1 or Vero cell lines. A. baumannii had high level of resistance to antibiotics. Most of the isolates harbored the fimH, afa/draBC, cnf1, csgA and cnf2, and the majority of A. baumannii produced strong biofilms. AgNPs inhibited the growth of A. baumannii efficiently with MIC ranging from 4 to 25 µg/ml. A. baumannii showed a reduced growth rate in the presence of AgNPs. The inhibitory activity and the anti-biofilm activity of AgNPs were more pronounced against the weak biofilm producers. Moreover, AgNPs decreased the expression of kpsMII , afa/draBC,bap, OmpA, and csuA/B genes. The in vitro infection model revealed a significant antibacterial activity of AgNPs against extracellular and intracellular A. baumannii. AgNPs highly interrupted bacterial multiplication and biofilm formation. AgNPs downregulated the transcription level of important virulence and biofilm-related genes. Our findings provide an additional step towards understanding the mechanisms by which sliver nanoparticles interfere with the microbial spread and persistence.

scholarly journals Evaluation of Antibacterial Activity of Cymbopogon citratus Ethanolic Leaf Crude Extract against Streptococcus pneumoniae isolated from Kampala International University Teaching Hospital Western Campus, Uganda

2019 ◽  
Vol 7 (1) ◽  
pp. 31-38
Author(s):  
Ibrahim Ntulume ◽  
Ninsiima Victoria ◽  
Abubakar Sunusi Adam ◽  
Adamu Almustapha Aliero
Keyword(s):  
Antibacterial Activity ◽  
Streptococcus Pneumoniae ◽  
Crude Extract ◽  
Clinical Isolates ◽  
University Teaching ◽  
Zone Of Inhibition ◽  
Cymbopogon Citratus ◽  
Alternative Intervention ◽  
Adults And Children

Streptococcus pneumoniae is the common cause of pneumonia, meningitis, bacteremia and Septicemia among adults and children worldwide. Resistance to antimicrobials agents has been reported among S. pneumoniae which necessitate the need for alternative intervention such as ethno-medicinal plants. Cymbopogon citratus is an ethno-medicinal plant which is known to have pharmacological activities including antibacterial activity. This study aimed at determining the in vitro antibacterial activity of C. citratus ethanolic leaves crude extract against clinical isolates of S.  pneumoniae. A fresh leaves of C. citratus were collected early in the morning; shed dried, pulverized and extracted using ethanol (96%) using standard extraction method. The antibacterial activity, Minimum Inhibitory and Minimum Bactericidal Concentrations of C. citratus ethanolic leaves crude extract were determined against clinical isolates of S. pneumoniae. C. citratus ethanolic leaves extract crude showed antibacterial activity against S. pneumoniae at 500mg/ml concentration with mean and standard deviation zone of inhibition (26.33 ± 1.53 mm) in comparison with that of 250mg/ml concentration which gave 20.33 ± 2.08 mm mean and standard zone of inhibition. The minimum inhibitory concentration of the plant crude extract against S. pneumoniae was 15.63 mg/ml while the minimum bactericidal concentration was 125mg/ml. The study found that C. citratus leaves ethanolic crude extract was active against S. pneumoniae. It is recommended that studies should be done focusing on isolation of specific phytochemicals of the C. citratus leaves crude extract and then determines their antibacterial activity against clinical isolates of S. pneumoniae. Int. J. Appl. Sci. Biotechnol. Vol 7(1): 31-38

scholarly journals The N-Acetylglucosaminidase LytB of Streptococcus pneumoniae Is Involved in the Structure and Formation of Biofilms

2020 ◽  
Vol 86 (10) ◽  
Author(s):  
Mirian Domenech ◽  
Ernesto García
Keyword(s):  
Streptococcus Pneumoniae ◽  
Biofilm Formation ◽  
Single Gene ◽  
Extracellular Polysaccharide ◽  
Extracellular Dna ◽  
Nasopharyngeal Colonization ◽  
Content Type ◽  
Daughter Cells ◽  
Biofilm Matrix

ABSTRACT The N-acetylglucosaminidase LytB of Streptococcus pneumoniae is involved in nasopharyngeal colonization and is responsible for cell separation at the end of cell division; thus, ΔlytB mutants form long chains of cells. This paper reports the construction and properties of a defective pneumococcal mutant producing an inactive LytB protein (LytBE585A). It is shown that an enzymatically active LytB is required for in vitro biofilm formation, as lytB mutants (either ΔlytB or producing the inactive LytBE585A) are incapable of forming substantial biofilms, despite that extracellular DNA is present in the biofilm matrix. Adding small amounts (0.5 to 2.0 μg/ml) of exogenous LytB or some LytB constructs restored the biofilm-forming capacity of lytB mutants to wild-type levels. The LytBE585A mutant formed biofilm more rapidly than ΔlytB mutants in the presence of LytB. This suggests that the mutant protein acted in a structural role, likely through the formation of complexes with extracellular DNA. The chain-dispersing capacity of LytB allowed the separation of daughter cells, presumably facilitating the formation of microcolonies and, finally, of biofilms. A role for the possible involvement of LytB in the synthesis of the extracellular polysaccharide component of the biofilm matrix is also discussed. IMPORTANCE It has been previously accepted that biofilm formation in S. pneumoniae must be a multigenic trait because the mutation of a single gene has led to only to partial inhibition of biofilm production. In the present study, however, evidence that the N-acetylglucosaminidase LytB is crucial in biofilm formation is provided. Despite the presence of extracellular DNA, strains either deficient in LytB or producing a defective LytB enzyme formed only shallow biofilms.

scholarly journals Comparative In Vitro Activities of Daptomycin and Vancomycin against Resistant Gram-Positive Pathogens

2000 ◽  
Vol 44 (12) ◽  
pp. 3447-3450 ◽  
Author(s):  
D. R. Snydman ◽  
N. V. Jacobus ◽  
L. A. McDermott ◽  
J. R. Lonks ◽  
J. M. Boyce
Keyword(s):  
Staphylococcus Aureus ◽  
Antibacterial Activity ◽  
Streptococcus Pneumoniae ◽  
Calcium Concentration ◽  
In Vitro Activity ◽  
Gram Positive ◽  
Methicillin Resistant ◽  
Vancomycin Resistant ◽  
Gram Positive Cocci

ABSTRACT The in vitro activity of daptomycin against 224 current gram-positive clinical isolates including vancomycin-resistantEnterococcus faecium (VREF), methicillin-resistantStaphylococcus aureus (MRSA), methicillin-resistantStaphylococcus spp. (MRSS), and penicillin-resistantStreptococcus pneumoniae (PRSP) was evaluated. The MICs at which 90% of isolates are inhibited for daptomycin and vancomycin, respectively, were as follows: MRSA, 1 and 2 μg/ml; MRSS, 1 and 4 μg/ml; PRSP, 1 and 0.5 μg/ml; and VREF, 2 and >64 μg/ml. Daptomycin was bactericidal against 82% of 17 VREF isolates. The antibacterial activity of daptomycin was strongly dependent on the calcium concentration of the medium. Daptomycin was active against all gram-positive cocci tested.

scholarly journals Enhanced antibacterial activity through silver nanoparticles deposited onto carboxylated graphene oxide surface

2021 ◽  
Author(s):  
Arturo Barjola ◽  
María Ángeles Tormo ◽  
Oscar Sahuquillo ◽  
Patricia Bernabé ◽  
José Manuel Pérez ◽  
...  
Keyword(s):  
Silver Nanoparticles ◽  
Antibacterial Activity ◽  
Graphene Oxide ◽  
Biofilm Formation ◽  
Material Surface ◽  
Oxide Surface ◽  
Main Role ◽  
Carboxylic Groups ◽  
Average Size

Abstract The strong bactericidal action of silver nanoparticles (AgNPs) is usually limited for their degree of aggregation. Deposition of AgNPs onto a graphene oxide (GO) surface to generate GO-Ag hybrids has been shown to be an effective method to control these aggregation problems. In this sense, a novel carboxylated graphene oxide-silver nanoparticle (GOCOOH-Ag) material has been synthesized and their antibacterial and biofilm formation inhibition have been studied.AgNPs decorating the GOCOOH surface achieved an average size of 6.74±0.25 nm, which was smaller than those of AgNPs deposited onto the GO surface. In addition, better distribution of AgNPs was obtained using carboxylated material. It is important to highlight the main role of the carboxylic groups in the nucleation and growth of the AgNPs that decorate the GO-based material surface.In vitro antibacterial activity and antibiofilm-forming action were tested against Gram-positive (Staphylococcus aureus and Staphylococcus epidermidis) and Gram-negative bacteria (Pseudomonas aeruginosa and Escherichia coli). Both GO-Ag and GOCOOH-Ag reduced the bacterial growth, analyzed by time-kill curves. However, the minimum inhibitory concentration and the minimum bactericidal concentration of GOCOOH-Ag were lower than those of GO-Ag for all strains studied, indicating that GOCOOH-Ag has better antibacterial activity. In addition, both nanomaterials prevent biofilm-formation, with a higher reduction of biofilm mass and cell viability in the presence of GOCOOH-Ag. The carboxylation functionalization in GO-based materials can be applied to improve the bactericidal and antibiofilm-forming action of the AgNPs.

scholarly journals Antibacterial Activity of Leaf Extracts of Anredera cordifolia (Ten.) Steenis and Muntingia calabura L. Against Streptococcus pneumoniae

2020 ◽  
Vol 7 (1) ◽  
pp. 1-9
Author(s):  
Nuke Annisa Nasution ◽  
I Made Artika ◽  
Dodi Safari
Keyword(s):  
Antibacterial Activity ◽  
Streptococcus Pneumoniae ◽  
Clinical Isolate ◽  
Antibacterial Agent ◽  
Antibacterial Agents ◽  
Leaf Extracts ◽  
Extract Concentration ◽  
Global Concern ◽  
Muntingia Calabura

Antibacterial resistance in Streptococcus pneumoniae has been increasing and is one of ongoing global concern.  The need to find new antibacterial agents against Streptococcus pneumoniae is of paramount importance. Medicinal plants are prospective sources of antibacterial agents. The aims of the present study were to determine the activity of leaf extraxt of Anredera cordifolia (Ten.) Steenis and Muntingia calabura L. against Streptococcus pneumoniae.  Leaves of Anredera cordifolia (Ten.) Steenis were extracted using 96% ethanol, while the leaves of Muntingia calabura L were extracted using 100% methanol.  The leaf extracts of the two plants obtained were bioassayed for antibacterial activity against Streptococcus pneumoniae ATCC 49619 and a clinical isolate Streptococcus pneumoniae PU 067.  Results showed that leaf extracts of both Anredera cordifolia (Ten.) Steenis and Muntingia calabura L. have antibacterial activity in vitro against Streptococcus pneumoniae ATCC 49619 at crude extract concentrations of 25%, 50%, 75% and 100% (w/v). Both plants extracts showed strongest activity against S. pneumoniae ATCC 49619 at extract concentration of 75%.   In addition, the extracts of both plants have inhibitory activity against growth of the clinical isolate Streptococcus pneumoniae PU 067. Both plant extracts showed strongest activity against S. pneumoniae PU 067 at extract concentration of 100%.  Therefore, leaf extracts of Anredera cordifolia (Ten.) Steenis and Muntingia calabura L. can potentially be used as a source of antibacterial agent for Streptococcus pneumoniae. Keywords: Antibacterial agent, Anredera cordifolia (Ten.) Steenis, Muntingia calabura L., Streptococcus pneumoniae.

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