Displaying publications 1 - 20 of 124 in total

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  1. Size selectivity in antibiofilm activity of 3-(diphenylphosphino)propanoic acid coated gold nanomaterials against Gram-positive Staphylococcus aureus and Streptococcus mutans
    Ahmed D, Anwar A, Khan AK, Ahmed A, Shah MR, Khan NA
    AMB Express, 2017 Nov 21;7(1):210.
    PMID: 29164404 DOI: 10.1186/s13568-017-0515-x
    Biofilm formation by pathogenic bacteria is one of the major threats in hospital related infections, hence inhibiting and eradicating biofilms has become a primary target for developing new anti-infection approaches. The present study was aimed to develop novel antibiofilm agents against two Gram-positive bacteria; Staphylococcus aureus (ATCC 43300) and Streptococcus mutans (ATCC 25175) using gold nanomaterials conjugated with 3-(diphenylphosphino)propionic acid (Au-LPa). Gold nanomaterials with different sizes as 2-3 nm small and 9-90 nm (50 nm average size) large were stabilized by LPa via different chemical synthetic strategies. The nanomaterials were fully characterized using atomic force microscope (AFM), transmission electron microscope, ultraviolet-visible absorption spectroscopy, and Fourier transformation infrared spectroscopy. Antibiofilm activity of Au-LPa nanomaterials was tested using LPa alone, Au-LPa and unprotected gold nanomaterials against the both biofilm-producing bacteria. The results showed that LPa alone did not inhibit biofilm formation to a significant extent below 0.025 mM, while conjugation with gold nanomaterials displayed manifold enhanced antibiofilm potential against both strains. Moreover, it was also observed that the antibiofilm potency of the Au-LPa nanomaterials varies with size variations of nanomaterials. AFM analysis of biofilms further complemented the assay results and provided morphological aspects of the antibiofilm action of Au-LPa nanomaterials.
    Matched MeSH terms: Gram-Positive Bacteria
  2. Fulltext Bioactive Compounds from the Bornean Endemic Plant Goniothalamus longistipetes
    Teo SP, Bhakta S, Stapleton P, Gibbons S
    Antibiotics (Basel), 2020 Dec 16;9(12).
    PMID: 33339285 DOI: 10.3390/antibiotics9120913
    The present study aimed to screen plants for bioactive compounds with potential antibacterial activities. In our efforts to evaluate plants from Borneo, we isolated and elucidated the structures of four natural products from the bioactive fraction of a chloroform extract of Goniothalamus longistipetes using various chromatographic and spectroscopic techniques. The bioactive compounds were identified as a known styryllactone, (+)-altholactone ((2S,3R,3aS,7aS)-3-hydroxy-2-phenyl-2,3,3a,7a-tetrahydrobenzo-5(4H)-5-one) (1), a new styryllactone, (2S,3R,3aS,7aS)-3-hydroxy-2-phenyl-2,3,3a,7a-tetrahydrobenzo-5(4H)-5-one) (2) as well as a new alkaloid, 2,6-dimethoxyisonicotinaldehyde (3) and a new alkenyl-5-hydroxyl-phenyl benzoic acid (4). 1 and 4 showed broad-spectrum anti-bacterial activities against Gram-positive and Gram-negative bacteria as well as acid-fast model selected for this study. Compound 2 only demonstrated activities against Gram-positive bacteria whilst 3 displayed selective inhibitory activities against Gram-positive bacterial strains. Additionally, their mechanisms of anti-bacterial action were also investigated. Using Mycobacterium smegmatis as a fast-growing model of tubercle bacilli, compounds 1, 2 and 4 demonstrated inhibitory activities against whole-cell drug efflux and biofilm formation; two key intrinsic mechanisms of antibiotic resistance. Interestingly, the amphiphilic compound 4 exhibited inhibitory activity against the conjugation of plasmid pKM101 in Escherichia coli using a plate conjugation assay. Plasmid conjugation is a mechanism by which Gram-positive and Gram-negative-bacteria acquire drug resistance and virulence. These results indicated that bioactive compounds isolated from Goniothalamus longistipetes can be potential candidates as 'hits' for further optimisation.
    Matched MeSH terms: Gram-Positive Bacteria
  3. Identification and characterization of the yellow pigment synthesized by Cupriavidus sp. USMAHM13
    Ramachandran H, Iqbal MA, Amirul AA
    Appl Biochem Biotechnol, 2014 Sep;174(2):461-70.
    PMID: 25099372 DOI: 10.1007/s12010-014-1080-2
    Microbial pigments are gaining intensive attention due to increasing awareness of the toxicity of synthetic colours. In this study, a novel polymer-producing bacterium designated as Cupriavidus sp. USMAHM13 was also found to produce yellow pigment when cultivated in nutrient broth. Various parameters such as temperature, pH and ratio of culture volume to flask volume were found to influence the yellow pigment production. UV-Visible, Fourier transform infrared and (13)C-nuclear magnetic resonance analyses revealed that the crude yellow pigment might probably represent new bioactive compound in the carotenoid family. The crude yellow pigment also exhibited a wide spectrum of antimicrobial activity against Gram-negative and Gram-positive bacteria with their inhibition zones and minimal inhibitory concentrations ranged from 25 to 38 mm and from 0.63 to 2.5 mg/ml, respectively. To the best of our knowledge, this is the first report on the identification and characterization of yellow pigment produced by bacterium belonging to the genus Cupriavidus.
    Matched MeSH terms: Gram-Positive Bacteria/drug effects
  4. Fulltext Evaluation of anti-bacterial and anti-oxidant potential of andrographolide and echiodinin isolated from callus culture of Andrographis paniculata Nees
    Arifullah M, Namsa ND, Mandal M, Chiruvella KK, Vikrama P, Gopal GR
    Asian Pac J Trop Biomed, 2013 Aug;3(8):604-10; discussion 609-10.
    PMID: 23905016 DOI: 10.1016/S2221-1691(13)60123-9
    To evaluate the anti-bacterial and anti-oxidant activity of andrographolide (AND) and echiodinin (ECH) of Andrographis paniculata.
    Matched MeSH terms: Gram-Positive Bacteria/drug effects
  5. Fulltext In vitro antimicrobial activity of mangrove plant Sonneratia alba
    Saad S, Taher M, Susanti D, Qaralleh H, Awang AF
    Asian Pac J Trop Biomed, 2012 Jun;2(6):427-9.
    PMID: 23569943 DOI: 10.1016/S2221-1691(12)60069-0
    To investigate the antimicrobial property of mangrove plant Sonneratia alba (S. alba).
    Matched MeSH terms: Gram-Positive Bacteria/drug effects*
  6. Fulltext Pharmacological screening of methanolic extract of Ixora species
    Latha LY, Darah I, Jain K, Sasidharan S
    Asian Pac J Trop Biomed, 2012 Feb;2(2):149-51.
    PMID: 23569886 DOI: 10.1016/S2221-1691(11)60210-4
    OBJECTIVE: To investigate the antimicrobial activity of methanolic extracts of different parts of Ixora species.

    METHODS: Antimicrobial activity was carried out using disc diffusion assay against fungi, gram-positive and gram-negative bacteria.

    RESULTS: All methanolic extracts of different parts of Ixora species showed a broad-spectrum of antibacterial and antiyeast activities, which inhibited the growth of at least one bacterium or yeast. There was no remarkable difference between different Ixora species observed in this study.

    CONCLUSIONS: The significant antimicrobial activity shown by this Ixora species suggests its potential against infections caused by pathogens. The extract may be developed as an antimicrobial agent.

    Matched MeSH terms: Gram-Positive Bacteria/drug effects*
  7. Fulltext Blechnum orientale Linn - a fern with potential as antioxidant, anticancer and antibacterial agent
    Lai HY, Lim YY, Kim KH
    BMC Complement Altern Med, 2010;10:15.
    PMID: 20429956 DOI: 10.1186/1472-6882-10-15
    Blechnum orientale Linn. (Blechnaceae) is used ethnomedicinally for the treatment of various skin diseases, stomach pain, urinary bladder complaints and sterilization of women. The aim of the study was to evaluate antioxidant, anticancer and antibacterial activity of five solvent fractions obtained from the methanol extract of the leaves of Blechnum orientale Linn.
    Matched MeSH terms: Gram-Positive Bacteria/drug effects
  8. Fulltext In vitro assessment of Pediococcus acidilactici Kp10 for its potential use in the food industry
    Abbasiliasi S, Tan JS, Bashokouh F, Ibrahim TAT, Mustafa S, Vakhshiteh F, et al.
    BMC Microbiol, 2017 May 23;17(1):121.
    PMID: 28535747 DOI: 10.1186/s12866-017-1000-z
    BACKGROUND: Selection of a microbial strain for the incorporation into food products requires in vitro and in vivo evaluations. A bacteriocin-producing lactic acid bacterium (LAB), Pediococcus acidilactici Kp10, isolated from a traditional dried curd was assessed in vitro for its beneficial properties as a potential probiotic and starter culture. The inhibitory spectra of the bacterial strain against different gram-positive and gram-negative bacteria, its cell surface hydrophobicity and resistance to phenol, its haemolytic, amylolytic and proteolytic activities, ability to produce acid and coagulate milk together with its enzymatic characteristics and adhesion property were all evaluated in vitro.

    RESULTS: P. acidilactici Kp10 was moderately tolerant to phenol and adhere to mammalian epithelial cells (Vero cells and ileal mucosal epithelium). The bacterium also exhibited antimicrobial activity against several gram-positive and gram-negative food-spoilage and food-borne pathogens such as Listeria monocytgenes ATCC 15313, Salmonella enterica ATCC 13311, Shigella sonnei ATCC 9290, Klebsiella oxytoca ATCC 13182, Enterobacter cloaca ATCC 35030 and Streptococcus pyogenes ATCC 12378. The absence of haemolytic activity and proteinase (trypsin) and the presence of a strong peptidase (leucine-arylamidase) and esterase-lipase (C4 and C8) were observed in this LAB strain. P. acidilactici Kp10 also produced acid, coagulated milk and has demonstrated proteolytic and amylolactic activities.

    CONCLUSION: The properties exhibited by P. acidilactici Kp10 suggested its potential application as probiotic and starter culture in the food industry.

    Matched MeSH terms: Gram-Positive Bacteria/drug effects
  9. Fulltext Purpura Fulminans: A rare presentation of Streptococcus Pneumoniae infection
    Teo HG, Wong JY, Ting TLL
    BMJ Case Rep, 2017 Oct 20;2017.
    PMID: 29054893 DOI: 10.1136/bcr-2017-221150
    A previously healthy man presented with fever for 2 days and rapidly progressive purpuric rash for 1 day. He progressed into hypotension, disseminated intravascular coagulation and refractory shock despite resuscitation and early antibiotic commencement. Blood culture grew Streptococcus pneumoniae This case report highlights the fact that purpura fulminans can be a rare presentation of S. pneumoniae infection as well.
    Matched MeSH terms: Gram-Positive Bacteria
  10. Short cationic lipopeptides as effective antibacterial agents: Design, physicochemical properties and biological evaluation
    Azmi F, Elliott AG, Marasini N, Ramu S, Ziora Z, Kavanagh AM, et al.
    Bioorg Med Chem, 2016 05 15;24(10):2235-41.
    PMID: 27048775 DOI: 10.1016/j.bmc.2016.03.053
    The spread of drug-resistant bacteria has imparted a sense of urgency in the search for new antibiotics. In an effort to develop a new generation of antibacterial agents, we have designed de novo charged lipopeptides inspired by natural antimicrobial peptides. These short lipopeptides are composed of cationic lysine and hydrophobic lipoamino acids that replicate the amphiphilic properties of natural antimicrobial peptides. The resultant lipopeptides were found to self-assemble into nanoparticles. Some were effective against a variety of Gram-positive bacteria, including strains resistant to methicillin, daptomycin and/or vancomycin. The lipopeptides were not toxic to human kidney and liver cell lines and were highly resistant to tryptic degradation. Transmission electron microscopy analysis of bacteria cells treated with lipopeptide showed membrane-damage and lysis with extrusion of cytosolic contents. With such properties in mind, these lipopeptides have the potential to be developed as new antibacterial agents against drug-resistant Gram-positive bacteria.
    Matched MeSH terms: Gram-Positive Bacteria/drug effects*; Gram-Positive Bacterial Infections/drug therapy
  11. Synthesis, in vitro antimycobacterial evaluation and docking studies of some new 5,6,7,8-tetrahydropyrido[4',3':4,5]thieno[2,3-d]pyrimidin-4(3H)-one schiff bases
    Narender M, Jaswanth S B, Umasankar K, Malathi J, Raghuram Reddy A, Umadevi KR, et al.
    Bioorg Med Chem Lett, 2016 Feb 01;26(3):836-840.
    PMID: 26755393 DOI: 10.1016/j.bmcl.2015.12.083
    Development of multidrug resistant (MDR) and extensively drug resistant (XDR) tuberculosis (TB) has been considered as major health burden, globally. In order to develop novel, potential molecules against drug resistant TB, twenty two (22) new 3-substituted-7-benzyl-5,6,7,8-tetrahydropyrido[4',3':4,5]thieno[2,3-d]pyrimidin-4(3H)-one (6a-k) and 3-substituted-7-benzyl-2-methyl-5,6,7,8-tetrahydropyrido[4',3':4,5]thieno[2,3-d]pyrimidin-4(3H)-one (7a-k) derivatives were designed and synthesized by using appropriate synthetic protocols. Pantothenate synthetase (PS) was considered as the target for the molecular docking studies and evaluated the binding pattern at active site, as PS plays a significant role in the biosynthesis of pantothenate in Mycobacterium tuberculosis (MTB). The preliminary in vitro antibacterial screening of test compounds was carried out against two strains of Gram-positive (Bacillus subtilis and Staphylococcus aureus) and Gram-negative (Escherichia coli and Klebsiella pneumoniae) bacteria. The antimycobacterial screening was performed against MTB H37Rv and an isoniazid-resistant clinical isolate of MTB. The compounds 6b, 6c, 6d, 6k, 7b, 7c, 7d and 7k exhibited promising antibacterial activity MIC in the range of 15-73 μM against all bacterial strains used and compounds 6d and 7b showed antimycobacterial activity (IC50 <340 μM in LRP assay) and (MIC <9 μM in broth microdilution method).
    Matched MeSH terms: Gram-Positive Bacteria/drug effects; Gram-Positive Bacteria/metabolism
  12. Fulltext Evaluation of two transformation protocols and screening of positive plasmid introduction into Bacillus cereus EB2, a gram-positive bacterium using qualitative analyses
    Sirajuddin SA, Sundram S
    Braz J Microbiol, 2020 Sep;51(3):919-929.
    PMID: 32078730 DOI: 10.1007/s42770-020-00241-0
    Both Gram-positive and Gram-negative bacteria can take up exogenous DNA when they are in a competent state either naturally or artificially. However, the thick peptidoglycan layer in Gram-positive bacteria's cell wall is considered as a possible barrier to DNA uptake. In the present work, two transformation techniques have been evaluated in assessing the protocol's ability to introduce foreign DNA, pBBRGFP-45 plasmid which harbors kanamycin resistance and green fluorescent protein (GFP) genes into a Gram-positive bacterium, Bacillus cereus EB2. B. cereus EB2 is an endophytic bacterium, isolated from oil palm roots. A Gram-negative bacterium, Pseudomonas aeruginosa EB35 was used as a control sample for both transformation protocols. The cells were made competent using respective chemical treatment to Gram-positive and Gram-negative bacteria, and kanamycin concentration in the selective medium was also optimized. Preliminary findings using qualitative analysis of colony polymerase chain reaction (PCR)-GFP indicated that the putative positive transformants for B. cereus EB2 were acquired using the second transformation protocol. The positive transformants were then verified using molecular techniques such as observation of putative colonies on specific media under UV light, plasmid extraction, and validation analyses, followed by fluorescence microscopy. Conversely, both transformation protocols were relatively effective for introduction of plasmid DNA into P. aeruginosa EB35. Therefore, this finding demonstrated the potential of chemically prepared competent cells and the crucial step of heat-shock in foreign DNA transformation process of Gram-positive bacterium namely B. cereus was required for successful transformation.
    Matched MeSH terms: Gram-Positive Bacteria/drug effects; Gram-Positive Bacteria/genetics; Gram-Positive Bacteria/growth & development
  13. Fulltext Characterization and safety evaluation of partially purified bacteriocin produced by Escherichia coli E isolated from fermented pineapple Ananas comosus (L.) Merr
    Le VT, Leelakriangsak M, Lee SW, Panphon S, Utispan K, Koontongkaew S
    Braz J Microbiol, 2019 Jan;50(1):33-42.
    PMID: 30637641 DOI: 10.1007/s42770-018-0014-5
    Antibacterial activity of cell-free supernatant from Escherichia coli E against selected pathogenic bacteria in food and aquaculture was the highest against Edwardsiella tarda 3, a significant aquaculture pathogen. Biochemical properties of the bacteriocins were studied and bacteriocin was found to be sensitive to proteinase K, demonstrating its proteinaceous nature. In addition, pH and temperature affected bacteriocin activity and stability. The bacteriocins were partially purified by ammonium sulfate precipitation. The antibacterial activity was only detected in 20% ammonium sulfate fraction and direct detection of its activity was performed by overlaying on the indicator strains. The inhibition zone associated with the antibacterial activity was detected in the sample overlaid by E. tarda 3 and Staphylococcus aureus DMST8840 with the relative molecular mass of about 27 kDa and 10 kDa, respectively. Bacteriocin showed no cytotoxic effect on NIH-3T3 cell line; however, two virulence genes, aer and sfa, were detected in the genome of E. coli E by PCR. The characteristics of bacteriocins produced by E. coli E exhibited the antibacterial activity against both Gram-positive and Gram-negative pathogenic bacteria and the safe use determined by cytotoxicity test which may have interesting biotechnological applications.
    Matched MeSH terms: Gram-Positive Bacteria/drug effects; Gram-Positive Bacteria/growth & development
  14. Antimicrobial properties of starch films incorporated with chitosan nanoparticles: In vitro and in vivo evaluation
    Shapi'i RA, Othman SH, Nordin N, Kadir Basha R, Nazli Naim M
    Carbohydr Polym, 2020 Feb 15;230:115602.
    PMID: 31887886 DOI: 10.1016/j.carbpol.2019.115602
    Chitosan nanoparticles (CNP) were synthesized via ionic gelation and used for the preparation of starch-based nanocomposite films containing different concentration of CNP (0, 5, 10, 15, 20% w/w). Antimicrobial properties of starch/CNP films was evaluated via in vitro (disc diffusion analysis) and in vivo (microbial count in wrapped cherry tomatoes) study. It was found that inhibitory zone of the 15 and 20% of starch/CNP films were clearly observed for all the tested bacteria including Bacillus cereus, Staphylococcus aureus, Escherichia coli and Salmonella typhimurium. In vivo study revealed that the starch/CNP film (15% w/w) was more efficient to inhibit the microbial growth in cherry tomatoes (7 × 102 CFU/g) compared to neat starch film (2.15 × 103 CFU/g) thus confirmed the potential application of the films as antimicrobial food packaging.
    Matched MeSH terms: Gram-Positive Bacteria/drug effects
  15. Fulltext Streptococcus pneumoniae Meningitis and Intracranial Vasculopathy: Clinical Correlation with Improving Transcranial Doppler Hemodynamics
    Idris MI, Tai SML, Tan CT, Tan KS
    Case Rep Neurol, 2020 12 14;12(Suppl 1):106-109.
    PMID: 33505281 DOI: 10.1159/000500950
    Streptococcus pneumoniae are Gram-positive bacteria that are responsible for many types of illnesses including pneumonia, sinus infections, and community-acquired meningitis. One important complication of bacterial meningitis is intracranial vasculopathy. Possible etiologies include vasculitis, vasospasm, endocarditis, or intra-arterial thrombosis. We present a case report of S. pneumoniae meningitis treated with antibiotics in which clinical improvement correlated with serial transcranial Doppler ultrasonography (TCD) improvement, suggesting vasospasm or vasculitis as a possible mechanism for intracranial vasculopathy.
    Matched MeSH terms: Gram-Positive Bacteria
  16. Biological properties of sodium alkyl methyl ester sulfonate/alkyltrimethylammonium bromide surfactant mixtures
    Wong SP, Lim WH, Cheng SF, Chuah CH
    Colloids Surf B Biointerfaces, 2012 Jan 1;89:48-52.
    PMID: 21937202 DOI: 10.1016/j.colsurfb.2011.08.021
    Quaternary ammonium compounds (QACs) are commonly used as disinfectant in medical care, food industry, detergents and glue industries. This is due to a small concentration of QACs is sufficient to inhibit the growth of various bacteria strains. In this work, the inhibitive power of cationic surfactants, alkyltrimethylammonium bromide (C(n)TAB) in the presence of anionic surfactants, sodium alkyl methyl ester α-sulfonate (C(n)MES) was studied. The growth inhibition test with gram-positive (Staphylococcus aureus) and gram-negative (Escherichia coli and Pseudomonas aeruginosa) bacteria were used to determine the toxicity of single and mixed surfactants. Results from this work showed that certain mixed surfactants have lower minimum inhibition concentration (MIC) as compared to the single C(n)TAB surfactants. Besides that, it was also found that alkyl chain length and the mixing ratios of the surfactants play a significant role in determining the mixture inhibitive power.
    Matched MeSH terms: Gram-Positive Bacteria/drug effects
  17. Graphene oxide exhibits differential mechanistic action towards Gram-positive and Gram-negative bacteria
    Pulingam T, Thong KL, Ali ME, Appaturi JN, Dinshaw IJ, Ong ZY, et al.
    Colloids Surf B Biointerfaces, 2019 Sep 01;181:6-15.
    PMID: 31103799 DOI: 10.1016/j.colsurfb.2019.05.023
    The antibacterial nature of graphene oxide (GO) has stimulated wide interest in the medical field. Although the antibacterial activity of GO towards bacteria has been well studied, a deeper understanding of the mechanism of action of GO is still lacking. The objective of the study was to elucidate the difference in the interactions of GO towards Gram-positive and Gram-negative bacteria. The synthesized GO was characterized by Ultraviolet-visible spectroscopy (UV-vis), Raman and Attenuated Total Reflectance-Fourier-transform infrared spectroscopy (ATR-FTIR). Viability, time-kill and Lactose Dehydrogenase (LDH) release assays were carried out along with FESEM, TEM and ATR-FTIR analysis of GO treated bacterial cells. Characterizations of synthesized GO confirmed the transition of graphene to GO and the antibacterial activity of GO was concentration and time-dependent. Loss of membrane integrity in bacteria was enhanced with increasing GO concentrations and this corresponded to the elevated release of LDH in the reaction medium. Surface morphology of GO treated bacterial culture showed apparent differences in the mechanism of action of GO towards Gram-positive and Gram-negative bacteria where cell entrapment was mainly observed for Gram-positive Staphylococcus aureus and Enterococcus faecalis whereas membrane disruption due to physical contact was noted for Gram-negative Escherichia coli and Pseudomonas aeruginosa. ATR-FTIR characterizations of the GO treated bacterial cells showed changes in the fatty acids, amide I and amide II of proteins, peptides and amino acid regions compared to untreated bacterial cells. Therefore, the data generated further enhance our understanding of the antibacterial activity of GO towards bacteria.
    Matched MeSH terms: Gram-Positive Bacteria/cytology; Gram-Positive Bacteria/drug effects*
  18. Antibacterial action of a heat-stable form of L-amino acid oxidase isolated from king cobra (Ophiophagus hannah) venom
    Lee ML, Tan NH, Fung SY, Sekaran SD
    Comp Biochem Physiol C Toxicol Pharmacol, 2011 Mar;153(2):237-42.
    PMID: 21059402 DOI: 10.1016/j.cbpc.2010.11.001
    The major l-amino acid oxidase (LAAO, EC 1.4.3.2) of king cobra (Ophiophagus hannah) venom is known to be an unusual form of snake venom LAAO as it possesses unique structural features and unusual thermal stability. The antibacterial effects of king cobra venom LAAO were tested against several strains of clinical isolates including Staphylococcus aureus, Staphylococcus epidermidis, Pseudomonas aeruginosa, Klebsiella pneumoniae, and Escherichia coli using broth microdilution assay. For comparison, the antibacterial effects of several antibiotics (cefotaxime, kanamycin, tetracycline, vancomycin and penicillin) were also examined using the same conditions. King cobra venom LAAO was very effective in inhibiting the two Gram-positive bacteria (S. aureus and S. epidermidis) tested, with minimum inhibitory concentration (MIC) of 0.78μg/mL (0.006μM) and 1.56μg/mL (0.012μM) against S. aureus and S. epidermidis, respectively. The MICs are comparable to the MICs of the antibiotics tested, on a weight basis. However, the LAAO was only moderately effective against three Gram-negative bacteria tested (P. aeruginosa, K. pneumoniae and E. coli), with MIC ranges from 25 to 50μg/mL (0.2-0.4μM). Catalase at the concentration of 1mg/mL abolished the antibacterial effect of LAAO, indicating that the antibacterial effect of the enzyme involves generation of hydrogen peroxide. Binding studies indicated that king cobra venom LAAO binds strongly to the Gram-positive S. aureus and S. epidermidis, but less strongly to the Gram-negative E. coli and P. aeruginosa, indicating that specific binding to bacteria is important for the potent antibacterial activity of the enzyme.
    Matched MeSH terms: Gram-Positive Bacteria/drug effects
  19. Antimicrobial Exploration Between Counterpart Endosymbiont and Host Plant (Tamarindus indica Linn.)
    Chigurupati S, Vijayabalan S, Selvarajan KK, Aldubayan M, Alhowail A, Mani V, et al.
    Curr Pharm Biotechnol, 2020;21(5):384-389.
    PMID: 31657678 DOI: 10.2174/1389201020666191028105325
    BACKGROUND: Endophytic bacteria produce various bioactive secondary metabolites, which benefit human health. Tamarindus indica L. is well known for its medicinal value in human health care. Several studies have reported on its biological effects from various parts of T. indica, but only a few studies have been devoted to examining the biological activity of endophytes of T. indica.

    OBJECTIVES: In the present study, an endophyte was isolated from the leaves of T. indica and screened for its antimicrobial potential.

    METHODS: The selected endophyte was identified by 16s rRNA partial genome sequencing and investigated for their antimicrobial potency. The preliminary phytochemical tests were conducted for the affirmation of phytoconstituents in the endophytic crude ethyl acetate extract of T. indica (TIM) and total phenolic content was performed. The antimicrobial potential of TIM was evaluated against human pathogenic ATCC gram-positive and gram-negative bacterial strains.

    RESULTS: TIM exhibited an appreciable amount of gallic acid equivalent phenolic content (21.6 ± 0.04 mg GAE/g of crude extract). TIM showed the Minimum Inhibitory Concentration (MIC) at 250 μg/mL and Minimum Bactericidal Concentration (MBC) at 500 μg/mL among the selected human pathogenic ATCC strains. At MIC of 500 μg/mL, TIM displayed a significant zone of inhibition against P. aeruginosa and N. gonorrhoeae.

    CONCLUSION: The results from our study highlighted for the first time the antimicrobial potential of endophytic bacterial strain Bacillus velezensis in T. indica leaves and it could be further explored as a source of natural antimicrobial agents.

    Matched MeSH terms: Gram-Positive Bacteria/drug effects
  20. Fulltext Antimycobacterial, antimicrobial, and biocompatibility properties of para-aminosalicylic acid with zinc layered hydroxide and Zn/Al layered double hydroxide nanocomposites
    Saifullah B, El Zowalaty ME, Arulselvan P, Fakurazi S, Webster TJ, Geilich BM, et al.
    Drug Des Devel Ther, 2014;8:1029-36.
    PMID: 25114509 DOI: 10.2147/DDDT.S63753
    The treatment of tuberculosis by chemotherapy is complicated due to multiple drug prescriptions, long treatment duration, and adverse side effects. We report here for the first time an in vitro therapeutic effect of nanocomposites based on para-aminosalicylic acid with zinc layered hydroxide (PAS-ZLH) and zinc-aluminum layered double hydroxides (PAS-Zn/Al LDH), against mycobacteria, Gram-positive bacteria, and Gram-negative bacteria. The nanocomposites demonstrated good antimycobacterial activity and were found to be effective in killing Gram-positive and Gram-negative bacteria. A biocompatibility study revealed good biocompatibility of the PAS-ZLH nanocomposites against normal human MRC-5 lung cells. The para-aminosalicylic acid loading was quantified with high-performance liquid chromatography analysis. In summary, the present preliminary in vitro studies are highly encouraging for further in vivo studies of PAS-ZLH and PAS-Zn/Al LDH nanocomposites to treat tuberculosis.
    Matched MeSH terms: Gram-Positive Bacteria/drug effects
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