scholarly journals Antimicrobial activity of selected natural products against Gram-positive, Gram-negative and Acid-fast bacterial pathogens

2012 ◽  
Vol 2 (1) ◽  
pp. 13 ◽  
Author(s):  
Niket Yadav ◽  
Ekta Yadav ◽  
Jagjit S. Yadav

Recurring epidemics of drug resistant bacterial diseases such as those caused by mycobacteria (tuberculosis and non-tuberculous infections), staphylococci (methicillin-resistant <em>Staphylococcus aureus</em> or MRSA infections) and various Gram-negative enterobacteria (enterobacterial infections) have reinforced the need to search for alternative antimicrobials. In this context, we investigated the anti-bacterial potential of nine different natural products and compared them with the antibiotic controls, using three test bacterial species, representing the Gram-negative (<em>Escherichia coli</em>), Gram-positive (<em>Staphylococcus epidermidis</em>), and Acid-fast (<em>Mycobacterium smegmatis</em>) pathogen groups. Six of the nine products showed detectable but variable zones of inhibition (mm2). The anti-bacterial activity (mm2 per 100 mg) of the extracts from the four solid natural products was in the following order for all three pathogen groups: Mint (<em>Mentha arvensis</em>) leaf extract, 264-930&gt;Mushroom (<em>Agaricus bisporus</em>) cap extract, 112-241&gt;Turmeric (<em>Curcuma longa</em>) root extract, 4-10&gt;Ginger (<em>Zingiber officinale</em>) root extract, 3-9. For the liquid products, the activity measured on 100 μL aliquots was in the following order: Eucalyptus (<em>Eucalyptus globules</em>) oil, 264-1044&gt;Mustard (<em>Brassica campestris</em> L. var. brown sarson) oil, 45-96. Taken together, these results indicated the highest activity in Mint extract and Eucalyptus oil against all three test organisms. However, the individual test strains showed the following variable order of susceptibility: Mint extract (<em>M. smegmatis</em>&gt;<em>E. coli</em>&gt;<em>S</em>. <em>epidermidis</em>); Eucalyptus oil (<em>M. smegmatis</em>&gt;<em>S. epidermidis</em>&gt;<em>E</em>. <em>coli</em>). Based on these results it can be concluded that Mint leaves and Eucalyptus oil have an unusually broad spectrum activity and may, therefore, be promising sources of new broad spectrum antimicrobials.

2021 ◽  
Author(s):  
◽  
Hadeel Alhazmi

This thesis describes phytochemical studies on the methanolic extract of Curcuma longa; a medicinally important plant used as indigenous medicine for the treatment of wounds in South Asian and African countries. The crude extract displayed antibacterial activity against the Gram-positive bacterium, Staphylococcus aureus, but was inactive against Gram-positive bacterium Streptococcus agalactiae. This extract also did not show antibacterial activity against Gram-negative bacteria, Escherichia coli and Pseudomonas aeruginosa. Based on the observed antibacterial activity, it was decided to carry out phytochemical investigation of crude methanolic extract of C. longa to isolate and characterize natural products and evaluate them for antimicrobial activity. These efforts resulted in the identification of three known natural products: curcumin (39) sclareolide (40) and atalantoflavone (41). Structures of these compounds were established with the aid of NMR spectroscopic studies. Compounds (40) and (41) have been isolated for the first time from this plant. Compounds (39-41) were found to be inactive against the Gram-positive bacterium, Staphylococcus aureus, and Gram-negative bacterium, Escherichia coli.


2021 ◽  
Author(s):  
Byungji Kim ◽  
Qinglin Yang ◽  
Leslie W. Chan ◽  
Sangeeta N. Bhatia ◽  
Erkki Ruoslahti ◽  
...  

RNAi-mediated immunotherapy provided by fusogenic porous silicon nanoparticles demonstrates superior therapeutic efficacy against both Gram-positive and Gram-negative bacterial infections compared with first-line antibiotics.


Diagnostics ◽  
2021 ◽  
Vol 11 (2) ◽  
pp. 349
Author(s):  
Sien Ombelet ◽  
Alessandra Natale ◽  
Jean-Baptiste Ronat ◽  
Olivier Vandenberg ◽  
Liselotte Hardy ◽  
...  

Bacterial identification is challenging in low-resource settings (LRS). We evaluated the MicroScan identification panels (Beckman Coulter, Brea, CA, USA) as part of Médecins Sans Frontières’ Mini-lab Project. The MicroScan Dried Overnight Positive ID Type 3 (PID3) panels for Gram-positive organisms and Dried Overnight Negative ID Type 2 (NID2) panels for Gram-negative organisms were assessed with 367 clinical isolates from LRS. Robustness was studied by inoculating Gram-negative species on the Gram-positive panel and vice versa. The ease of use of the panels and readability of the instructions for use (IFU) were evaluated. Of species represented in the MicroScan database, 94.6% (185/195) of Gram-negative and 85.9% (110/128) of Gram-positive isolates were correctly identified up to species level. Of species not represented in the database (e.g., Streptococcus suis and Bacillus spp.), 53.1% out of 49 isolates were incorrectly identified as non-related bacterial species. Testing of Gram-positive isolates on Gram-negative panels and vice versa (n = 144) resulted in incorrect identifications for 38.2% of tested isolates. The readability level of the IFU was considered too high for LRS. Inoculation of the panels was favorably evaluated, whereas the visual reading of the panels was considered error-prone. In conclusion, the accuracy of the MicroScan identification panels was excellent for Gram-negative species and good for Gram-positive species. Improvements in stability, robustness, and ease of use have been identified to assure adaptation to LRS constraints.


Micromachines ◽  
2018 ◽  
Vol 9 (8) ◽  
pp. 367 ◽  
Author(s):  
Yuguang Liu ◽  
Dirk Schulze-Makuch ◽  
Jean-Pierre de Vera ◽  
Charles Cockell ◽  
Thomas Leya ◽  
...  

Single-cell sequencing is a powerful technology that provides the capability of analyzing a single cell within a population. This technology is mostly coupled with microfluidic systems for controlled cell manipulation and precise fluid handling to shed light on the genomes of a wide range of cells. So far, single-cell sequencing has been focused mostly on human cells due to the ease of lysing the cells for genome amplification. The major challenges that bacterial species pose to genome amplification from single cells include the rigid bacterial cell walls and the need for an effective lysis protocol compatible with microfluidic platforms. In this work, we present a lysis protocol that can be used to extract genomic DNA from both gram-positive and gram-negative species without interfering with the amplification chemistry. Corynebacterium glutamicum was chosen as a typical gram-positive model and Nostoc sp. as a gram-negative model due to major challenges reported in previous studies. Our protocol is based on thermal and chemical lysis. We consider 80% of single-cell replicates that lead to >5 ng DNA after amplification as successful attempts. The protocol was directly applied to Gloeocapsa sp. and the single cells of the eukaryotic Sphaerocystis sp. and achieved a 100% success rate.


2014 ◽  
Vol 58 (8) ◽  
pp. 4911-4914 ◽  
Author(s):  
Gerald A. Denys ◽  
Chris M. Pillar ◽  
Daniel F. Sahm ◽  
Peter O'Hanley ◽  
Jackson T. Stephens

ABSTRACTThis study summarizes the topical E-101 solution susceptibility testing results for 760 Gram-positive and Gram-negative target pathogens collected from 75 U.S. sites between 2008 and 2012 and 103 ESKAPE pathogens. E-101 solution maintained potent activity against all bacterial species studied for each year tested, with MICs ranging from <0.008 to 0.25 μg porcine myeloperoxidase (pMPO)/ml. These results confirm that E-101 solution retains its potent broad-spectrum activity against U.S. clinical isolates and organisms with challenging resistance phenotypes.


2020 ◽  
Vol 13 (10) ◽  
pp. 2243-2251
Author(s):  
Azhar G. Shalaby ◽  
Neveen R. Bakry ◽  
Abeer A. E. Mohamed ◽  
Ashraf A. Khalil

Background and Aim: Flinders Technology Associates (FTA) cards simplify sample storage, transport, and extraction by reducing cost and time for diagnosis. This study evaluated the FTA suitability for safe transport and storage of Gram-positive and Gram-negative bacterial cells of animal origin on its liquid culture form and from organ impression smears (tissues) under the same routine condition of microbiological laboratory along with detecting their nucleic acid over different storage conditions. Materials and Methods: Increase in bacterial count from 104 to 107 (colony-forming units/mL) of 78 isolates representing seven bacterial species was applied onto cards. FTA cards were grouped and inoculated by these bacteria and then stored at different conditions of 24-27°C, 4°C, and –20°C for 24 h, for 2 weeks, for 1 and 3 month storage, respectively. Bacteriological examination was done, after which bacterial DNA was identified using specific primers for each bacterial type and detected by polymerase chain reaction (PCR). Results: The total percentage of recovered bacteria from FTA cards was 66.7% at 24-27–C for 24 h, the detection limit was 100% in Gram-positive species, while it was 57.4% in Gram-negative ones. Regarding viable cell detection from organ impression smears, it was successful under the previous conditions. No live bacterial cells were observed by bacteriological isolation rather than only at 24-27°C for 24 h storage. All bacterial DNA were sufficiently confirmed by the PCR technique at different conditions. Conclusion: Overall, the FTA card method was observed to be a valid tool for nucleic acid purification for bacteria of animal origin in the form of culture or organ smears regardless of its Gram type and is used for a short time only 24 h for storage and transport of live bacteria specifically Gram-positive type. Moreover, the bacterial nucleic acid was intact after storage in –20°C for 3 months and was PCR amplifiable.


2021 ◽  
Vol 3 (1) ◽  
pp. 047-055
Author(s):  
Pimpliskar Mukesh ◽  
SoumyaGounder ◽  
Rahul Jadhav

Background: Handwashing is underlined as the absolute most significant measure to forestall cross-transmission of small-scale life forms and consequently to forestall nosocomial contaminations. Be that as it may, under routine emergency clinic practice consistent with this measure is still unsatisfactorily low, under half in many investigations distributed in the previous 20 years. This consistent finding is stressing because ongoing investigations have demonstrated that this degree of consistency won't decrease the danger of transmission of multi- medicate safe microscopic organisms in the emergency clinics. Results: In the present investigation effect of marketed hand washed namely Lifebuoy, Dettol and Savlon were tested on bacteria E. coli, S.aureus, S.pyogen, Klebshiella and, fungi Candida albicans. All the handwash at concentrated level found to be effective but only Dettol hand wash could give inhibitory action at 25ug/ml against Klebshiella while others at50ug/ml. Conclusions: Soapex and Dettol soap had broad spectrum activity as it inhibited the growth of Gram positive (Streptococcus pyogen) and Gram-negative (Escherichia coli). Liquid handwash such as Lifebuoy,Dettol and Savlon showed broad spectrum activity on both Gram-positive and Gram negative test microorganisms.


Parasitology ◽  
2019 ◽  
Vol 147 (1) ◽  
pp. 29-38
Author(s):  
Rory Gough ◽  
Joel Barratt ◽  
Damien Stark ◽  
John Ellis

AbstractThe presence of bacterial DNA in Dientamoeba fragilis DNA extracts from culture poses a substantial challenge to sequencing the D. fragilis genome. However, elimination of bacteria from D. fragilis cultures has proven difficult in the past, presumably due to its dependence on some unknown prokaryote/s. This study explored options for removal of bacteria from D. fragilis cultures and for the generation of genome sequence data from D. fragilis. DNA was extracted from human faecal samples and xenic D. fragilis cultures. Extracts were subjected to 16S ribosomal DNA bacterial diversity profiling. Xenic D. fragilis cultures were then subject to antibiotic treatment regimens that systematically removed bacterial species depending on their membrane structure (Gram-positive or Gram-negative) and aerobic requirements. The impact of these treatments on cultures was assessed by 16S amplicon sequencing. Prior to antibiotic treatment, the cultures were dominated by Gram-negative bacteria. Addition of meropenem to cultures eliminated anaerobic Gram-negative bacteria, but it also led to protozoan death after 5 days incubation. The seeding of meropenem resistant Klebsiella pneumoniae strain KPC-2 into cultures before treatment by meropenem prevented death of D. fragilis cells beyond this 5 day period, suggesting that one or more species of Gram-negative bacteria may be an essential nutritional requirement for D. fragilis. Gram-positive cells were completely eliminated using vancomycin without affecting trophozoite growth. Finally, this study shows that genome sequencing of D. fragilis is feasible following bacterial elimination from cultures as the result of the major advances occurring in bioinformatics. We provide evidence on this fact by successfully sequencing the D. fragilis 28S large ribosomal DNA subunit gene using culture-derived DNA.


2002 ◽  
Vol 46 (10) ◽  
pp. 3133-3141 ◽  
Author(s):  
George Tegos ◽  
Frank R. Stermitz ◽  
Olga Lomovskaya ◽  
Kim Lewis

ABSTRACT Plant antimicrobials are not used as systemic antibiotics at present. The main reason for this is their low level of activity, especially against gram-negative bacteria. The reported MIC is often in the range of 100 to 1,000 μg/ml, orders of magnitude higher than those of common broad-spectrum antibiotics from bacteria or fungi. Major plant pathogens belong to the gram-negative bacteria, which makes the low level of activity of plant antimicrobials against this group of microorganisms puzzling. Gram-negative bacteria have an effective permeability barrier, comprised of the outer membrane, which restricts the penetration of amphipathic compounds, and multidrug resistance pumps (MDRs), which extrude toxins across this barrier. It is possible that the apparent ineffectiveness of plant antimicrobials is largely due to the permeability barrier. We tested this hypothesis in the present study by applying a combination of MDR mutants and MDR inhibitors. A panel of plant antimicrobials was tested by using a set of bacteria representing the main groups of plant pathogens. The human pathogens Pseudomonas aeruginosa, Escherichia coli, and Salmonella enterica serovar Typhimurium were also tested. The results show that the activities of the majority of plant antimicrobials were considerably greater against the gram-positive bacteria Staphylococcus aureus and Bacillus megaterium and that disabling of the MDRs in gram-negative species leads to a striking increase in antimicrobial activity. Thus, the activity of rhein, the principal antimicrobial from rhubarb, was potentiated 100- to 2,000-fold (depending on the bacterial species) by disabling the MDRs. Comparable potentiation of activity was observed with plumbagin, resveratrol, gossypol, coumestrol, and berberine. Direct measurement of the uptake of berberine, a model plant antimicrobial, confirmed that disabling of the MDRs strongly increases the level of penetration of berberine into the cells of gram-negative bacteria. These results suggest that plants might have developed means of delivering their antimicrobials into bacterial cells. These findings also suggest that plant antimicrobials might be developed into effective, broad-spectrum antibiotics in combination with inhibitors of MDRs.


1976 ◽  
Vol 39 (2) ◽  
pp. 90-94 ◽  
Author(s):  
MARY L. SANDFORD ◽  
B. E. LANGLOIS

Three growth patterns (no effect, slight inhibition, or complete inhibition) were observed when bacterial species common to the dairy-food industry were grown in media containing 50 or 100 ppm DDT, dieldrin, or endrin. The pattern obtained appeared to depend on species and type and concentration of pesticide. All pesticides studied had a greater inhibitory effect on gram positive species than they had on gram negative species when grown in broth. Acid production by lactic acid bacteria was inhibited in broth plus 5 ppm chlordane or heptachlor but unaffected in skimmilk plus up to 100 ppm of these pesticides. Generation times for gram negative species grown in broth plus 10 ppm chlordane or heptachlor were similar to those obtained in controls. Growth of gram positive species was inhibited in broth plus 10 ppm of these pesticides but unaffected in skimmilk containing similar pesticide concentrations. Generation times for several gram negative species were increased by 10 ppm heptachlor in skimmilk.


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