scholarly journals Efficacy of leaf extracts of Psidium guajava (L.) on enteric bacterial isolates from faecally impacted groundwater

Author(s):  
A. O. Sule ◽  
A. O. Olalemi ◽  
A. O. Ogundare

Abstract The efficacy of leaf extracts of guava Psidium guajava (L.) were assessed on enteric bacteria isolated from two wells (W1 and W2) prone to faecal contamination in Akure, Nigeria. The load of enteric bacteria in the water samples were determined using standard microbiological method. Leaf extracts of P. guajava (L.) were prepared using ethanol and hot distilled water and the antibacterial effects of the extracts on bacterial isolates were determined using agar well diffusion method. Phytochemical components of the leaf extracts were carried out using standard methods. Results revealed the following mean concentrations of enteric bacteria in W1 and W2: Salmonella (3.8 and 3.9 log10 CFU/100 ml) and Shigella (3.6 and 3.7 log10 CFU/100 ml). The ethanol leaf extracts of P. guajava (L.) exhibited a zone of inhibition of 22 mm at 200 mg/ml on Shigella and no zone of inhibition was observed on Salmonella. The phytochemical components of ethanol and hot distilled water leaf extracts of P. guajava (L.) revealed the presence of saponin as (13.64 mg/g) and (59.82 mg/g). The findings of this study revealed that ethanol leaf extracts of P. guajava (L.) may be useful as antibacterial agent against Shigella.

Author(s):  
D. Muthuselvam ◽  
Kathick Kathick

Delonix elata L., belongs to family Fabaceae used by the traditional various medicinal practices to cure jaundice, skin disease, heart disease, cancer cell formation, physiological abnormalities, heptoprotective, bronchial and rheumatic problems. The present study was screen the antimicrobial and phytochemical activity of alkaloid leaf extracts. This extracts was assessed on multidrug resistant clinical isolated from both gram positive, gram negative and antifungal strains including Bacillus subtilis, Staphylococcus aureus, Escherchia coli, Pseudomonas aeruginosa, Candida albicans and Aspergillus niger. The zone of inhibition was determined by Agar well diffusion method with various concentration. GC- MS analysis was performed to identify major bioactive compounds present in the extracts. The GC – MS studies shown the present of 25 compound were identified in the leaf extract composition. The antimicrobial analysis revealed that C. albicans showed a highest zone of inhibition 25mm at 100 mg/ml of extracts. Present finding suggest that D. elata as plant pharmaceutical and pharmacological importance.


2018 ◽  
Vol 54 (4) ◽  
pp. 294
Author(s):  
S Zuhaira ◽  
Noorhaniz Mohd Nizam ◽  
PM Ridzuan

Antibiotic is a type of medication that helps in fighting bacterial infection. Treating bacterial infections in clinical setting become more complicated and costly due to drug resistance. This study was conducted to determine the antibacterial potential of Psidium guajava Linn leaf extracts against Gram-positive and Gram-negative bacteria. P. guajava Linn leaf was obtained from Research Orchards at University Putra Malaysia (UPM). Leaves were extracted using three types of extracts; hot, cold and methanol extract. Freeze dried was used in this study and temperature was set at -104°C for 24 hours. Antibacterial testing was determined using disc diffusion and well diffusion method. Antibacterial activity was evaluated by measuring the inhibitory zone of the tested bacteria. Phytochemical analysis was conducted by adding few drop of diluted NaOH (Sodium Hydroxide) solution to detect the active flavanoid from leaves extract. Antimicrobial activity showed all extracts were effective against Gram-positive and Gram-negative bacteria. Phytochemical analysis of P. guajava Linn leaf extracts showed the methanol extract indicating the presence of tannins, phenols, flavonoids, terpenoids, glycosides and saponins. Results showed that P. guajava Linn leaf was effective against Gram-positive and Gram-negative bacteria, and pythochemical analysis also exhibited a few active compounds that were determined. P. guajava Linn leaf had potential natural product that may be used for further analysis in the future research.


INDIAN DRUGS ◽  
2015 ◽  
Vol 52 (04) ◽  
pp. 37-41
Author(s):  
S. M Pawaskar ◽  
◽  
K. C. Sasangan

The present study was undertaken to evaluate in vitro antimicrobial activity of the successive leaf extracts of Cynodon dactylon in petroleum ether, ethyl acetate, acetone, ethanol, methanol and water, against various gram positive & gram negative bacterial strains using zone of inhibition. Both Agar well diffusion method & Agar disc diffusion method were used to evaluate the antibacterial efficacy. The microorganisms used in the test were – Escherichia coli, Proteus vulgaris, Staphylococcus aureus, Klebsiella pneumoniae, Pseudomonas aeruginosa, Shigella flexneri, Salmonella typhi, Salmonella paratyphi A, Salmonella paratyphi B, Bacillus subtilis, Streptococcus pyogenes, Vibrio cholerac and Enterobacter aerogenes. Two fungal strains - Candida albicans and Saccharomyces cerevisiae were also tested to evaluate the antifungal potential of the said plant extract. The reference antibiotics chloramphenicol & ampicillin (antibacterial); nystatin & clotrimazole and (antifungal) were also tested against these standard microorganisms used in the assay and the results were compared with that of the plant extracts.The results of the study revealed that all the seven successive extracts of the leaf powder of Cynodon dactylon ( L.) Pers. exhibited prominent antimicrobial and antifungal activity against all microorganisms used in the study. The nonpolar extracts i.e. petroleum ether, ethyl acetate and acetone showed the most significant antibacterial and antifungal activity against all tested organisms. The petroleum ether and ethyl acetate extracts showing maximum inhibition in the range of 8 mm - 15 mm. This was closely followed by, acetone extract, which showed the inhibition in the range of 9 mm - 13 mm.


Author(s):  
Flávia A. Gonçalves ◽  
Manoel Andrade Neto ◽  
José N. S. Bezerra ◽  
Andrew Macrae ◽  
Oscarina Viana de Sousa ◽  
...  

Guava leaf tea of Psidium guajava Linnaeus is commonly used as a medicine against gastroenteritis and child diarrhea by those who cannot afford or do not have access to antibiotics. This study screened the antimicrobial effect of essential oils and methanol, hexane, ethyl acetate extracts from guava leaves. The extracts were tested against diarrhea-causing bacteria: Staphylococcus aureus, Salmonella spp. and Escherichia coli. Strains that were screened included isolates from seabob shrimp, Xiphopenaeus kroyeri (Heller) and laboratory-type strains. Of the bacteria tested, Staphylococcus aureus strains were most inhibited by the extracts. The methanol extract showed greatest bacterial inhibition. No statistically significant differences were observed between the tested extract concentrations and their effect. The essential oil extract showed inhibitory activity against S. aureus and Salmonella spp. The strains isolated from the shrimp showed some resistance to commercially available antibiotics. These data support the use of guava leaf-made medicines in diarrhea cases where access to commercial antibiotics is restricted. In conclusion, guava leaf extracts and essential oil are very active against S. aureus, thus making up important potential sources of new antimicrobial compounds.


2018 ◽  
Vol 29 ◽  
pp. 70-77 ◽  
Author(s):  
Anjana Devkota ◽  
Ritu Kumari Das

Antibacterial activities of Xanthium strumarium L. (Asteraceae) was carried out in laboratory. Distilled water and methanol extracts of the leaves of plant was prepared. The antibacterial activity was studied against six pathogenic bacteria, three gram negative: Klebsiella pneumoniae (ATCC 15380), Proteus mirabilis (ATCC 49132), Escherichia coli (ATCC 25922) and three gram positive: Bacillus subtilis (ATCC 6633), Enterococcus faecalis (ATCC 29212), Staphylococcus aureus (ATCC 25932) at different concentrations (50 mg/ml, 100 mg/ml, 150 mg/ml, 200 mg/ ml, 250 mg/ml) of leaf extracts of X. strumurium. The phytochemical screening depicted the presence of terpenoids, saponins, flavonoids, tannins and alkaloids. The antibacterial activity of extracts was determined by disc diffusion method and zone of inhibition (ZOI) was measured. Gram negative bacteria was found more resistant than gram positive bacteria. The most susceptible bacterium was S. aureus while the most resistant bacterium was E. coli. Methanolic extract was found more effective than distilled water. These findings suggest that extracts obtained from leaves of X. strumurium possess biobactericidal potential, which can suitably be exploited for making antibacterial drugs.J. Nat. Hist. Mus. Vol. 29, 2015, Page: 70-77


2020 ◽  
Author(s):  
◽  
David Serunjogi ◽  
Kizito Muwonge

Background: Plant species such as the guava have been used in Uganda and elsewhere in the world to treat some of the medical conditions associated with bacteria, this is due to the increased number of drug resistant bacteria in the world. In this study, the antimicrobial activity of guava leaf extracts against some of the disease causing bacteria isolated from Kisubi hospital in Uganda is discussed. Methods: The guava leafs were collected from a plantation near Zika forest in Uganda (0°7′27″N 32°31′32″E / 0.12417°N 32.52556°E / 0.12417; 32.52556) and samples were put in a bag and transferred to the university laboratory where they were identified. The extracts were obtained by maceration using distilled water, 30%, 50% and 70 % methanol as the extraction solvents. Antimicrobial susceptibility testing was conducted using the disc diffusion method. Results: Gram-negative Escherichia coli was sensitive to the plant extract and synthetic commercial drugs such as trimethoprim-sulfamethozole, ciprofloxacin, and Gentamicin. Pseudomonas aeruginosa was resistant to all drugs. Streptococcus pneumonia and Staphylococcus aureus were all sensitive to the plant extracts with measurable inhibition zones. Conclusion: The Guava tree leaf crude extracts have antimicrobial activity against drug-resistant bacteria. More studies should be carried out to know the potency and the concentration of different plant origin extracts.


2020 ◽  
Author(s):  
◽  
David Serunjogi

Abstract Background: Plant species such as the guava have been used in Uganda and elsewhere in the world to treat some of the medical conditions associated with bacteria, this is due to the increased number of drug resistant bacteria in the world. In this study, the antimicrobial activity of guava leaf extracts against some of the disease causing bacteria isolated from Kisubi hospital in Uganda is discussed. Methods: The guava leafs were collected from a plantation near Zika forest in Uganda (0°7′27″N 32°31′32″E / 0.12417°N 32.52556°E / 0.12417; 32.52556) and samples were put in a bag and transferred to the university laboratory where they were identified. The extracts were obtained by maceration using distilled water, 30%, 50% and 70 % methanol as the extraction solvents. Antimicrobial susceptibility testing was conducted using the disc diffusion method. Results: Gram-negative Escherichia coli was sensitive to the plant extract and synthetic commercial drugs such as trimethoprim-sulfamethozole, ciprofloxacin, and Gentamicin. Pseudomonas aeruginosa was resistant to all drugs. Streptococcus pneumonia and Staphylococcus aureus were all sensitive to the plant extracts with measurable inhibition zones. Conclusion: The Guava tree leaf crude extracts have antimicrobial activity against drug-resistant bacteria. More studies should be carried out to know the potency and the concentration of different plant origin extracts.


2017 ◽  
Vol 2017 ◽  
pp. 1-5 ◽  
Author(s):  
Spoorthi Banavar Ravi ◽  
Sudarshini Nirupad ◽  
Prashanthi Chippagiri ◽  
Rohit Pandurangappa

Background. Many plants or herbs exhibit potent antimicrobial activity against various microorganisms. They have no side effects and presumably act against and modulate the factors that are crucial for microbial survival or their activity. Streptococcus mutans is a pioneer bacteria implicated in dental caries. This study aims to evaluate the antimicrobial activity of garlic bulbs, pudina leaves, and mango and eucalyptus twig extracts on Streptococcus mutans by evaluating their zone of inhibition and determining their minimum inhibitory concentration (MIC). Methods. Microbiological assay (well diffusion method) to determine zone of inhibition against pure forms of Streptococcus mutans was performed. The antibacterial effects of methanolic extracts of mango twigs, eucalyptus twigs, pudina leaves, and garlic bulbs were studied. Test compounds were further evaluated for their MIC. Results. Extracts derived from mango and eucalyptus twigs showed significant antibacterial effects at test concentrations. Pudina and garlic extracts did not show any significant antibacterial effects at similar concentrations. Upon further evaluation of the 2 positive compounds for their MIC, mango twigs demonstrated more antimicrobial potential than eucalyptus twigs at a lower concentration. Conclusion. Our observations indicated that the mango twig extracts possess higher antibacterial effects against Streptococcus mutans than other compounds at specific test concentration.


2021 ◽  
pp. 030157422098818
Author(s):  
Cheepurupalli Meher Vineesha ◽  
D Praveen Kumar Varma ◽  
P Arun Bhupathi ◽  
CV Padma Priya ◽  
M Anoosha ◽  
...  

Aim and Objectives: To compare and evaluate the antibacterial efficacy of various nanoparticles incorporated in orthodontic primer with that of conventional antimicrobial agents at different concentrations on Streptococcus mutans ( S. mutans) strain. Materials and Methods: Transbond XT Primer was mixed with 2.5% and 5% benzalkonium chloride (BAC), 0.2% and 2.5% chlorhexidine, 1% and 3% titanium dioxide (TiO2) nanoparticles, 0.2% and 0.5% nanohydroxyapatite, and 0.2% and 0.5% silica-doped nanohydroxyapatite powders. Antibacterial activity against S. mutans for all the materials was evaluated by the disk diffusion method for periods of 48 (T1) and 72 (T2) hours. Results: There was a significant increase in the antimicrobial activity of the orthodontic primer modified by the addition of antibacterial agents. The highest zone of inhibition against S. mutans was observed for silica-doped nanohydroxyapatite of 0.5% (11.03 mm) among all the nanoparticles, which was similar to the conventional antibacterial agents used in our study. Conclusions: • Among all the groups, BAC at 5% concentration showed the highest antimicrobial activity, and the least activity was exhibited by 1% TiO2 nanoparticles. • Silica-doped nanohydroxyapatite at 0.5% expressed the greatest antibacterial activity among all the nanoparticles. • All the materials showed sustained antibacterial activity even after 72 hours.


Author(s):  
D. A. Awomukwu ◽  
C. K. Anumudu ◽  
A. J. Ogbolosingha

The research was undertaken to investigate the comparative phytochemical and in-vitro antibacterial activity of the single and combined strengths of the leaf extracts of Ocimum gratissimum Linn and Gongronema latifolium Benth. on some enteric bacterial isolates. The sensitivity test and minimum inhibitory concentration (MIC) were carried out using a modified agar-well diffusion method.  The enteric bacterial isolates tested included Escherichia coli, Shigella dysenteriae, Salmonella Typhi and Enterobacter aerogenes.  Standard methods were applied to obtain the ethanol and aqueous leaf extracts. The ethanol extracts of O. gratissimum and G. latifolium produced highly significant inhibitory activity against all the enteric bacterial isolates tested.  Comparatively, the ethanol plant extracts were more potent than the commercially available drug, Ciprofloxacin and the aqueous plant extracts. The isolates were sensitive at a minimum inhibitory concentration of 1.25 mg/ml for the ethanol extract but varied from 2.5 mg/ml - 5.0mg/ml in the aqueous extract.  It was also observed that the synergistic antibacterial effect of the medicinal plant extracts was greater than the singular antibacterial effect of the individual plant extracts in both the ethanol and aqueous extracts. The potency of the individual extracts and the combined effect may be due to the presence of flavonoids, alkaloids, phenols, tannins and saponins in the leaves of the plants.  This study partly validates the use of the plant extracts in the treatment of disease caused by the enteric bacterial isolates by multiple traditional medicine practitioners in Nigeria, however, strict adherence to dosage is recommended.  The leaf extract is a potential source of the new drug if the components are purified and enhanced for treating infections caused by these enteric pathogens.


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