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The Results of Two-stage Revision for Methicillin-resistant Periprosthetic Joint Infection (PJI) of the Hip

Santoso A, Yoon TR, Park KS, Anwar IB, Utomo P, Soetjahjo B, et al.

Malays Orthop J, 2020 Mar;14(1):18-23.
PMID: 32296477 DOI: 10.5704/MOJ.2003.003

Introduction: Periprosthetic joint infection (PJI) of the hip due to methicillin-resistant bacteria is difficult to treat and remain a challenge for arthroplasty surgeon.
Material and Methods: Retrospective review was done to the patients who received two-stage revisions with an antibiotic loaded cement-spacer for PJI of the hip between January 2010 to May 2015. We found 65 patients (65 hips) with positive culture findings. Eight patients were lost to follow-up and excluded from the study. Among the rest of the 57 patients, methicillin-resistant infection (MR Group) was found in 28 cases. We also evaluate the 29 other cases that caused by the other pathogen as control group. We compared all of the relevant medical records and the treatment outcomes between the two groups.
Results: The mean of follow-up period was 33.7 months in the methicillin-resistant group and 28.4 months in the control group (p = 0.27). The causal pathogens in the methicillin-resistant group were: Methicillin-resistant Staphylococcus aureus (MRSA) in 10 cases, Methicillin-resistant Staphylococcus epidermidis (MRSE) in 16 cases and Methicillin-resistant coagulase-negative Staphylococcus (MRCNS) in two cases. The reimplantation rate was 92.8% and 89.6% in the methicillin-resistant and control group, respectively (p= 0.66). The rates of recurrent infection after reimplantation were 23.1% (6/26) in the methicillin-resistant group and 7.6% (2/26) in the control group (p= 0.12). The overall infection control rate was 71.4% (20/28) and 89.6% (26/29) in the methicillin-resistant and control group, respectively (p = 0.08). Both groups showed comparable baseline data on mean age, BMI, gender distribution, preoperative ESR/CRP/WBC and comorbidities.
Conclusions: Two-stage revision procedure resulted in low infection control rate and high infection recurrency rate for the treatment of methicillin-resistant periprosthetic joint infection (PJI) of the hip. Development of the treatment strategy is needed to improve the outcome of methicillin-resistant periprosthetic joint infection (PJI) of the hip.

Matched MeSH terms: Methicillin-Resistant Staphylococcus aureus
Fulltext The Photocatalytic Effects of Modified Hydrothermal Nanotitania Extraction on the Skin and Behavior of Sprague-Dawley Rats

Harun AM, Awang H, Noor NFM, Makhatar NM, Yusoff ME, Affandi NDN, et al.

Biomed Res Int, 2021;2021:6173143.
PMID: 34859102 DOI: 10.1155/2021/6173143

BACKGROUND: Potential antibacterial substances, such as titanium dioxide (TiO2), are being extensively studied throughout the research world. A modified hydrothermal nanotitania extraction was shown to inhibit Staphylococcus aureus growth in the laboratory. However, the toxicity effect of the extract on rats is unknown. In this study, we observed the effects of a modified hydrothermal nanotitania extraction on the skin and behavior of Sprague-Dawley rats.
METHODS: Sprague-Dawley (Rattus norvegicus) rats were used as the experimental animals. The skin around the dorsum of the tested animals was shaved and pasted with 0.1 mg and 0.5 mg of the nanotitania extraction. The color and condition of the pasted area and the behavior of the animals were observed.
RESULTS: 0.1 mg nanotitania extraction application on the dorsum of the rat produced no skin color changes at day 1, day 3, day 5, or day 7 postapplication. There were no changes in their behavior up to day 7 with no skin rashes or skin scratches seen or fur changes. However, 0.5 mg of nanotitania extraction resulted in redness and less fur regrowth at day 7.
CONCLUSIONS: A 0.1 mg modified nanotitania extraction was observed to have no effect on the skin of Sprague-Dawley rats.

Matched MeSH terms: Staphylococcus aureus/drug effects
Fulltext The Antibacterial Activity of Dayak Onion (Eleutherine palmifolia (L.) Merr) towards Pathogenic Bacteria

Harlita TD, Oedjijono, Asnani A

Trop Life Sci Res, 2018 Jul;29(2):39-52.
PMID: 30112140 DOI: 10.21315/tlsr2018.29.2.4

Antibacterial activity of indigenous Dayak onion (Eleutherine palmifolia (L.) Merr) was investigated. The Dayak onion was solvent extracted with n-hexane, ethyl acetate, and ethanol 96% consecutively. Each extract was tested its antibacterial activity towards methicillin-resistant Staphylococcus aureus (MRSA), Bacillus cereus, Shigella sp., and Pseudomonas aeruginosa using disc diffusion method. The test results showed that the n-hexane, ethyl acetate, and ethanol 96% extracts positively inhibited the growth of MRSA, B. cereus, Shigella sp., and P. aeruginosa. The highest inhibition activity of each extract was obtained with 10 mg/mL of extract concentration; whereas the minimum inhibitory concentration (MIC) of each extract was 2 mg/mL. Extract with the highest inhibition activity was ethyl acetate extract against B. cereus (139.58%). TLC evaluation of ethyl acetate extract showed four spots and bioautography indicated that ethyl acetate extract contained four types of compounds with inhibition activity against B. cereus, in which two compounds have higher antibacterial activity than the other two.

Matched MeSH terms: Methicillin-Resistant Staphylococcus aureus
Temporal changes in the genotypes of methicillin-resistant Staphylococcus aureus strains isolated from a tertiary Malaysian hospital based on MLST, spa, and mec-associated dru typing

Lim KT, Hanifah YA, Yusof MY, Goering RV, Thong KL

Diagn Microbiol Infect Dis, 2012 Oct;74(2):106-12.
PMID: 22770652 DOI: 10.1016/j.diagmicrobio.2012.05.033

Methicillin-resistant Staphylococcus aureus (MRSA) is one of the main bacterial pathogens responsible for nosocomial infections leading to pneumonia, bloodstream, skin, and soft tissue infections. The objective of this study was to investigate the genomic changes of MRSA in a tertiary hospital between the years 2003, 2004, 2007, and 2008. One hundred fifty-four MRSA strains were characterized by multilocus sequence typing (MLST), spa, and mec-associated dru typing. Among the 154 strains, 29 different dru, 15 spa, and 8 MLST types were identified. Seven sequence types (STs) (ST239, ST22, ST5, ST6, ST80, ST573, and ST241) were identified among 2007-08 strains, although only 2 STs (ST239 and ST20) were observed among 2003 strains. Clones ST239-t037-dt13g, ST22-t032-(dt10a and dt10aw), and 28 other MRSA clones being introduced in 2007-2008 have replaced the ST239-t037 (dt13d, 14h, 13i, 13l, 13m, 15m, 15l, and 11al) clones present in 2003. The predominant MLST clone, ST239 (90.3%), was further distinguished into 7 different spa types and 26 different dru types, including 17 novel dru types. Maximum parsimony tree based on dru repeats revealed that 10 dru types (dt11am, dt13j, dt15n, dt13q, dt13n, dt13p, dt13f, dt13ao, dt12j, dt7v) shared the same MLST-spa types with dt13d, suggesting that these MRSA clones might have evolved from ST239-t037-dt13d. In conclusion, our data showed that the ST239-t037-dt13d clone and other MRSA clones in 2003 were replaced by ST239-t037-dt13g and other new emerging spa and dru types.

Matched MeSH terms: Methicillin-Resistant Staphylococcus aureus/classification*; Methicillin-Resistant Staphylococcus aureus/genetics; Methicillin-Resistant Staphylococcus aureus/isolation & purification*
Tea Polyphenols Inhibit the Activity and Toxicity of Staphylococcus aureus by Destroying Cell Membranes and Accumulating Reactive Oxygen Species

Zhong W, Tang M, Xie Y, Huang X, Liu Y

Foodborne Pathog Dis, 2023 Jul;20(7):294-302.
PMID: 37347934 DOI: 10.1089/fpd.2022.0085

Staphylococcus aureus can cause bacterial food intoxication and seriously affect human health. Tea polyphenols (TP) are a kind of natural, safe, and broad-spectrum bacteriostatic substances, with a wide range of bacteriostatic effects. In the study, we explored the possible bacteriostatic mode of TP. The minimum inhibitory concentration of TP against S. aureus was 64 μg/mL. Protein, DNA, and K+ leak experiments, fluorescence microscopy, and transmission electron microscopy suggested that TP disrupt cell membranes, leading to intracellular component loss. By studying the effect of TP on the toxicity of S. aureus, it was found that the expression levels of two toxin genes, coa and spa, were downregulated by 2.37 and 32.6, respectively. Furthermore, after treatment with TP, a large number of reactive oxygen species (ROS) were propagated and released, leading to oxidative stress in cells. We speculated that the bacteriostatic mechanism of TP may be through the destruction of the cell membrane and ROS-mediated oxidative stress. Meanwhile, the hemolysis activity proved the safety of TP. Our results suggested that TP may be a potential antimicrobial agent for food.

Matched MeSH terms: Staphylococcus aureus*
Fulltext Targeting the hard to reach: challenges and novel strategies in the treatment of intracellular bacterial infections

Kamaruzzaman NF, Kendall S, Good L

Br J Pharmacol, 2017 Jul;174(14):2225-2236.
PMID: 27925153 DOI: 10.1111/bph.13664

Infectious diseases continue to threaten human and animal health and welfare globally, impacting millions of lives and causing substantial economic loss. The use of antibacterials has been only partially successful in reducing disease impact. Bacterial cells are inherently resilient, and the therapy challenge is increased by the development of antibacterial resistance, the formation of biofilms and the ability of certain clinically important pathogens to invade and localize within host cells. Invasion into host cells provides protection from both antibacterials and the host immune system. Poor delivery of antibacterials into host cells causes inadequate bacterial clearance, resulting in chronic and unresolved infections. In this review, we discuss the challenges associated with existing antibacterial therapies with a focus on intracellular pathogens. We consider the requirements for successful treatment of intracellular infections and novel platforms currently under development. Finally, we discuss novel strategies to improve drug penetration into host cells. As an example, we discuss our recent demonstration that the cell penetrating cationic polymer polyhexamethylene biguanide has antibacterial activity against intracellular Staphylococcus aureus.
LINKED ARTICLES: This article is part of a themed section on Drug Metabolism and Antibiotic Resistance in Micro-organisms. To view the other articles in this section visit http://onlinelibrary.wiley.com/doi/10.1111/bph.v174.14/issuetoc.

Matched MeSH terms: Staphylococcus aureus/drug effects
Synthesis, spectral analysis and biological evaluation of 2-{[(morpholin-4-yl)ethyl]thio}-5-phenyl/aryl-1,3,4-oxadiazole derivatives

Ur-Rehman A, Khan SG, Naqvi SAR, Ahmad M, Akhtar N, Bokhari TH, et al.

Pak J Pharm Sci, 2021 Jan;34(1(Special)):441-446.
PMID: 34275792

A series of new derivatives of 4-(2-chloroethyl)morpholine hydrochloride (5) were efficiently synthesized. Briefly, different aromatic organic acids (1a-f) were refluxed to acquire respective esters (2a-f) using conc. H2SO4 as catalyst. The esters were subjected to nucleophillic substitution by monohydrated hydrazine to acquire hydrazides (3a-f). The hydrazides were cyclized with CS2 in the presence of KOH to yield corresponding oxadiazoles (4a-f). Finally, the derivatives, 6a-f, were prepared by reacting oxadiazoles (4a-f) with 5 using NaH as activator. Structures of all the derivatives were elucidated through 1D-NMR EI-MS and IR spectral data. All these molecules were subjected to antibacterial and hemolytic activities and showed good antibacterial and hemolytic potential relative to the reference standards.

Matched MeSH terms: Staphylococcus aureus/drug effects
Synthesis, evaluation, molecular docking, and molecular dynamics studies of novel N-(4-[pyridin-2-yloxy]benzyl)arylamine derivatives as potential antitubercular agents

Verma R, Boshoff HIM, Arora K, Bairy I, Tiwari M, Varadaraj BG, et al.

Drug Dev Res, 2020 05;81(3):315-328.
PMID: 31782209 DOI: 10.1002/ddr.21623

A new series of novel triclosan (2,4,4'-trichloro-2'-hydroxydiphenylether) analogues were designed, synthesized, and screened for their in vitro antimycobacterial and antibacterial activities. Most of the compounds showed significant activity against Mycobacterium tuberculosis H37Rv strain with minimum inhibitory concentration (MIC) values in 20-40 μM range in GAST/Fe medium when compared with triclosan (43 μM) in the first week of assay, and after additional incubation, seven compounds, that is, 2a, 2c, 2g, 2h, 2i, 2j, and 2m, exhibited MIC values at the concentration of 20-40 μM. The compounds also showed more significant activity against Bacillus subtilis and Staphylococcus aureus. The synthesized compounds showed druggable properties, and the predicted ADME (absorption, distribution, metabolism, and excretion) properties were within the acceptable limits. The in silico studies predicted better interactions of compounds with target protein residues and a higher dock score in comparison with triclosan. Molecular dynamics simulation study of the most active compound 2i was performed in order to further explore the stability of the protein-ligand complex and the protein-ligand interaction in detail.

Matched MeSH terms: Staphylococcus aureus
Fulltext Synthesis, characterization, controlled release, and antibacterial studies of a novel streptomycin chitosan magnetic nanoantibiotic

Hussein-Al-Ali SH, El Zowalaty ME, Hussein MZ, Ismail M, Webster TJ

Int J Nanomedicine, 2014;9:549-57.
PMID: 24549109 DOI: 10.2147/IJN.S53079

This study describes the preparation, characterization, and controlled release of a streptomycin-chitosan-magnetic nanoparticle-based antibiotic in an effort to improve the treatment of bacterial infections. Specifically, chitosan-magnetic nanoparticles were synthesized by an incorporation method and were characterized by Fourier transform infrared spectroscopy, X-ray diffraction, thermogravimetric analysis, and vibrating sample magnetometry. Streptomycin was incorporated into the nanoparticles to form a streptomycin-coated chitosan-magnetic nanoparticle (Strep-CS-MNP) nanocomposite. The release profiles showed an initially fast release, which became slower as time progressed. The percentage of drug released after 350 minutes was around 100%, and the best fit mathematical model for drug release was the pseudo-second order model. The Strep-CS-MNP nanocomposite showed enhanced antibacterial activity against methicillin-resistant Staphylococcus aureus. This study forms a significant basis for further investigation of the Strep-CS-MNP nanocomposite in the treatment of various bacterial infections.

Matched MeSH terms: Methicillin-Resistant Staphylococcus aureus/drug effects
Fulltext Synthesis, characterization and application of gelatin-carboxymethyl cellulose blend films for preservation of cherry tomatoes and grapes

Samsi MS, Kamari A, Din SM, Lazar G

J Food Sci Technol, 2019 Jun;56(6):3099-3108.
PMID: 31205364 DOI: 10.1007/s13197-019-03809-3

In the present study, gelatin-carboxymethyl cellulose blend film was synthesized, characterized and applied for the first time to preserve cherry tomatoes (Solanum lycopersicum var. cerasiforme) and grapes (Vitis vinifera). Gelatin (Gel) film forming solution was incorporated with carboxymethyl cellulose (CMC) at three volume per volume (Gel:CMC) ratios, namely 75:25, 50:50 and 25:75. CMC treatment has improved the transparency, tensile strength (TS), elongation at break (EAB), water vapor permeability and oxygen permeability of gelatin films. A pronounced effect was obtained for 25Gel:75CMC film. The TS and EAB values were increased from 25.98 MPa and 2.34% (100Gel:0CMC) to 37.54 MPa and 4.41% (25Gel:75CMC), respectively. A significant improvement in antimicrobial property of gelatin films against two food pathogens, namely Escherichia coli (E. coli) and Staphylococcus aureus (S. aureus) was obtained in the presence of CMC. The effectiveness of gelatin-CMC blend films to extend the shelf life of agricultural products was evaluated in a 14-day preservation study. The gelatin-CMC films were successfully controlled the weight loss and browning index of the fruits up to 50.41% and 31.34%, respectively. Overall, gelatin-CMC film is an environmental friendly film for food preservation.

Matched MeSH terms: Staphylococcus aureus
Synthesis, characterization and antimicrobial investigation of mechanochemically processed silver doped ZnO nanoparticles

Talari MK, Abdul Majeed AB, Tripathi DK, Tripathy M

Chem Pharm Bull (Tokyo), 2012;60(7):818-24.
PMID: 22790812

The application of nanomaterials has gained considerable momentum in various fields in recent years due to their high reactivity, excellent surface properties and quantum effects in the nanometer range. The properties of zinc oxide (ZnO) vary with its crystallite size or particle size and often nanocrystalline ZnO is seen to exhibit superior physical and chemical properties due to their higher surface area and modified electronic structure. ZnO nanoparticles are reported to exhibit strong bacterial inhibiting activity and silver (Ag) has been extensively used for its antimicrobial properties since ages. In this study, Ag doped ZnO nanoparticles were synthesized by mechanochemical processing in a high energy ball mill and investigated for antimicrobial activity. The nanocrystalline nature of zinc oxide was established by X-ray diffraction (XRD) studies. It is seen from the XRD data obtained from the samples, that crystallite size of the zinc oxide nanoparticles is seen to decrease with increasing Ag addition. Field emission scanning electron microscopy (FESEM) and transmission electron microscopy (TEM) data also supported the nanoparticle formation during the synthesis. The doped nanoparticles were subjected to antimicrobial investigation and found that both increase in Ag content and decrease in particle size contributed significantly towards antimicrobial efficiency. It was also observed that Ag doped ZnO nanoparticles possess enhanced antimicrobial potential than that of virgin ZnO against the studied microorganisms of Escherichia coli and Staphylococcus aureus.

Matched MeSH terms: Staphylococcus aureus/drug effects
Synthesis, characterization and antibacterial activity of mono-, di- and tri-tosylate of glycerol

Yusrabbil Amiyati Yusof, Azhar Ariffin

Sains Malaysiana, 2016;45:621-625.

Glycerol is a valuable co-product from oleochemical industry such as from fatty acid and biodiesel production. By having three hydroxyl groups in its molecule, glycerol can undergo chemical modifications that lead to many possible applications. This paper reports the tosylation process of glycerol with para-toluenesulfonyl chloride (p-TsCl). Reaction of glycerol with p-TsCl in the presence of a base produced mono-, di- and tri-tosylate of glycerol even though the reaction was carried out at the mole ratio of 1.2:1.0 of glycerol to p-TsCl. The compounds were successfully isolated and characterized. Mono-, di- and tri-tosylate of glycerol exhibited inhibitory activity against Staphylococcus aureus (gram positive bacteria) and Pseudomonas aeruginosa (gram negative bacteria).

Matched MeSH terms: Staphylococcus aureus
Fulltext Synthesis, antibacterial and thermal studies of cellulose nanocrystal stabilized ZnO-Ag heterostructure nanoparticles

Azizi S, Ahmad MB, Hussein MZ, Ibrahim NA

Molecules, 2013 May 28;18(6):6269-80.
PMID: 23760028 DOI: 10.3390/molecules18066269

Synthesis of ZnO-Ag heterostructure nanoparticles was carried out by a precipitation method with cellulose nanocrystals (CNCs) as a stabilizer for antimicrobial and thermal studies. ZnO-Ag nanoparticles were obtained from various weight percentages of added AgNO₃ relative to Zn precursors for evaluating the best composition with enhanced functional properties. The ZnO-Ag/CNCs samples were characterized systematically by TEM, XRD, UV, TGA and DTG. From the TEM studies we observed that ZnO-Ag heterostructure nanoparticles have spherical shapes with size diameters in a 9-35 nm range. The antibacterial activities of samples were assessed against the bacterial species Salmonella choleraesuis and Staphylococcus aureus. The CNC-stabilized ZnO-Ag exhibited greater bactericidal activity compared to cellulose-free ZnO-Ag heterostructure nanoparticles of the same particle size. The incorporation of ZnO-Ag hetreostructure nanoparticles significantly increased the thermal stability of cellulose nanocrystals.

Matched MeSH terms: Staphylococcus aureus/drug effects
Synthesis, Structural Characterization, and Bioactivity of the Stable Peptide RCB-1 from Ricinus communis

Boldbaatar D, Gunasekera S, El-Seedi HR, Göransson U

J Nat Prod, 2015 Nov 25;78(11):2545-51.
PMID: 26509914 DOI: 10.1021/acs.jnatprod.5b00463

The Ricinus communis biomarker peptides RCB-1 to -3 comprise homologous sequences of 19 (RCB-1) or 18 (RCB-2 and -3) amino acid residues. They all include four cysteine moieties, which form two disulfide bonds. However, neither the 3D structure nor the biological activity of any of these peptides is known. The synthesis of RCB-1, using microwave-assisted, Fmoc-based solid-phase peptide synthesis, and a method for its oxidative folding are reported. The tertiary structure of RCB-1, subsequently established using solution-state NMR, reveals a twisted loop fold with antiparallel β-sheets reinforced by the two disulfide bonds. Moreover, RCB-1 was tested for antibacterial, antifungal, and cytotoxic activity, as well as in a serum stability assay, in which it proved to be remarkably stable.

Matched MeSH terms: Staphylococcus aureus/drug effects
Synthesis, Characterization, Antimicrobial and Anticancer Studies of Metal Complexes of 2-methoxy-4-((3-methylpyridin-2-ylimino)methyl)phenol

Mishra A, Tahlan S, Ramasamy K, Lim SM, Shah SAA, Narasimhan B

Mini Rev Med Chem, 2020;20(13):1311-1317.
PMID: 32368977 DOI: 10.2174/1389557520666200505124125

BACKGROUND: Being derived from primary amine and aromatic aldehyde, Schiff base and their complexes have an imperative role in the improvement of inorganic chemistry, which are broadly studied as coordination compounds and are gradually becoming more important in biochemical and analytical applications.
METHODS: They have also been used for antibacterial, antifungal, anticancer, antitubercular activities. Novel synthesised Schiff's base 2-methoxy-4-((3-methylpyridin-2-ylimino)methyl)phenol (SB) and its metal complexes (Zn[II], Cu[II], Co[II] and Ni[II]) were characterised by UV, IR and NMR spectroscopy. Formation of the Schiff base and the metal (Zn[II], Cu[II], Co[II] and Ni[II]) chelates was supported by spectral and analytical data. The ligand and metal complexes have been screened for their antibacterial activity against Staphylococcus aureus, Salmonella typhi, Escherichia coli, Klebsiella pneumoniae and antifungal activity against the fungi Candida albicans and Aspergillus niger. Further, the synthesised compounds were also screened for antiproliferative activity against the human colorectal carcinoma (HCT116) cell line using the Sulforhodamine B assay.
RESULT: Metal complexes formed were found to enhance the potency of the Schiff base due to coordination with a copper complex, showing better activity than others.
CONCLUSION: Copper complex was observed to be more potent than other complexes against all the pathogenic microbes and cancer cell line (HCT116).

Matched MeSH terms: Staphylococcus aureus
Fulltext Synthesis of silver nanoparticles in montmorillonite and their antibacterial behavior

Shameli K, Ahmad MB, Zargar M, Yunus WM, Rustaiyan A, Ibrahim NA

Int J Nanomedicine, 2011;6:581-90.
PMID: 21674015 DOI: 10.2147/IJN.S17112

Silver nanoparticles (Ag NPs) were synthesized by the chemical reducing method in the external and interlamellar space of montmorillonite (MMT) as a solid support at room temperature. AgNO(3) and NaBH(4) were used as a silver precursor and reducing agent, respectively. The most favorable experimental conditions for synthesizing Ag NPs in the MMT are described in terms of the initial concentration of AgNO(3). The interlamellar space limits changed little (d-spacing = 1.24-1.47 nm); therefore, Ag NPs formed on the MMT suspension with d-average = 4.19-8.53 nm diameter. The Ag/MMT nanocomposites (NCs), formed from AgNO(3)/MMT suspension, were characterizations with different instruments, for example UV-visible, PXRD, TEM, SEM, EDXRF, FT-IR, and ICP-OES analyzer. The antibacterial activity of different sizes of Ag NPs in MMT were investigated against Gram-positive, ie, Staphylococcus aureus and methicillin-resistant S. aureus (MRSA) and Gram-negative bacteria, ie, Escherichia coli, Escherichia coli O157:H7, and Klebsiella pneumoniae, by the disk diffusion method using Mueller-Hinton agar (MHA). The smaller Ag NPs were found to have significantly higher antibacterial activity. These results showed that Ag NPs can be used as effective growth inhibitors in different biological systems, making them applicable to medical applications.

Matched MeSH terms: Methicillin-Resistant Staphylococcus aureus/drug effects
Fulltext Synthesis of silver nanoparticle-decorated hydroxyapatite nanocomposite with combined bioactivity and antibacterial properties

Bee SL, Bustami Y, Ul-Hamid A, Lim K, Abdul Hamid ZA

J Mater Sci Mater Med, 2021 Aug 23;32(9):106.
PMID: 34426879 DOI: 10.1007/s10856-021-06590-y

Combination of bioactive material such as hydroxyapatite (HAp) with antibacterial agents would have great potential to be used as bone implant materials to avert possible bacterial infection that can lead to implant-associated diseases. The present study aimed to develop an antibacterial silver nanoparticle-decorated hydroxyapatite (HAp/AgNPs) nanocomposite using chemical reduction and thermal calcination approaches. In this work, natural HAp that was extracted from chicken bone wastes is used as support matrix for the deposition of silver nanoparticles (AgNPs) to produce HAp/AgNPs nanocomposite. XRD, FESEM-EDX, HRTEM, and XPS analyses confirmed that spherical AgNPs were successfully synthesized and deposited on the surface of HAp particles, and the amount of AgNPs adhered on the HAp surface increased with increasing AgNO3 concentration used. The synthesized HAp/AgNPs nanocomposites demonstrated strong antibacterial activity against Staphylococcus aureus bacteria, where the antibacterial efficiency is relied on the amount and size of deposited AgNPs. In addition, the in vitro bioactivity examination in Hank's balanced salt solution showed that more apatite were grown on the surface of HAp/AgNPs nanocomposite when AgNO3 concentration used >1 wt.%. Such nanocomposite with enhanced bioactivity and antibacterial properties emerged as a promising biomaterial to be applied for dentistry and orthopedic implantology.

Matched MeSH terms: Staphylococcus aureus/drug effects; Staphylococcus aureus/growth & development
Synthesis of halogenated azo-aspirin analogues from natural product derivatives as the potential antibacterial agents

Ngaini Z, Mortadza NA

Nat Prod Res, 2019 Dec;33(24):3507-3514.
PMID: 29911437 DOI: 10.1080/14786419.2018.1486310

Chemical modification of medicines from natural product-based molecules has become of interest in recent years. In this study, a series of halogenated azo derivatives 1a-d were synthesised via coupling reaction, followed by Steglich esterification with aspirin (a natural product derivative) to form azo derivatives 2a-d. While, halogenated azo-aspirin 3a-d were synthesised via direct coupling reaction of aspirin and diazonium salt. Bacteriostatic activity was demonstrated against E. coli and S. aureus via turbidimetric kinetic method. Compound 3a-d showed excellent antibacterial activities against E. coli (MIC 75-94 ppm) and S. aureus (MIC 64-89 ppm) compared to ampicillin (MIC 93 and 124 ppm respectively), followed by 1a-d and 2a-d. The presence of reactive groups of -OH, N=N, C=O and halogens significantly contribute excellent interaction towards E. coli and S. aureus. Molecular dockings analysis of 3a against MIaC protein showed binding free energy of -7.2 kcal/mol (E. coli) and -6.6 kcal/mol (S. aureus).

Matched MeSH terms: Staphylococcus aureus/drug effects
Synthesis of cephradine metal complexes and its anti-bacterial evaluation

Iqbal Hussain, Syed Salman, Sarwat Iftikhar, Samin Jan, Junaid Akhter, Muhammad Ramzan, et al.

Sains Malaysiana, 2018;47:749-754.

Cephradine belongs to the first generation cephalosporin having a broad range of anti-bacterial activities. In the
present work, Cephradine wasreacted with different metal salts. These metal salts were Iron, Copper, Cobalt and Nickel
salts. All the complexes of Cephradine metals were synthesized at room temperature using a mechanical vibrator.
The reactions yielded the coordinated complexes within 5-10 min with improved product yield. The synthesized
complexes were analyzed for their antibacterial power using disc diffused assay. All the Cephradine complexes showed
powerful antibacterial activity. The Co, Cu, Ni and Sn complexes showed good antibacterial activities 18.5 mm by Cu
complexes against S. typhi, 17 mm against B. subtillus 16.5 mm against S. aureus, 16 mm against S. coccus. Similarly
Sn complexes exhibited 17 mm zone of inhibition against S. coccus and 15.5 mm against B. subtillus. Cobalt and Ni
complexes also shed significant inhibition activities against bacterial pathogenic bacterial strains. The study is of
particular importance and new, using mechanical vibrator for the first time. The product yield is also comparatively
good with short reaction time.

Matched MeSH terms: Staphylococcus aureus
Synthesis of ZnO nanoparticles with chitosan as stabilizing agent and their antibacterial properties against Gram-positive and Gram-negative bacteria

Yusof NAA, Zain NM, Pauzi N

Int J Biol Macromol, 2019 Mar 01;124:1132-1136.
PMID: 30496864 DOI: 10.1016/j.ijbiomac.2018.11.228

Antibacterial activity of zinc oxide (ZnO) nanoparticles have received significant interest, particularly by the implementation of nanotechnology to synthesize particles in nanometer region. ZnO nanoparticles were successfully synthesized through microwave heating by using chitosan as a stabilizing agent and characterized by UV-vis, FTIR, XRD and FESEM-EDX. The aim of the present study is to determine the antibacterial activity of ZnO nanoparticles against Gram-positive bacterium Staphylococcus aureus (S. aureus) and Gram-negative bacterium Escherichia coli (E. coli). The antibacterial effect of ZnO nanoparticles was investigated for the inhibition zone and inactivation of cell growth. The absorption of ZnO nanoparticles was found to be around 360 nm. FTIR results showed the stretching mode of ZnO nanoparticles at 475 cm-1 of the absorption band. EDX results indicated that ZnO nanoparticles have been successfully formed with an atomic percentage of zinc and oxygen at 23.61 and 46.57% respectively. X-ray diffraction result was confirmed the single-phase formation of ZnO nanoparticles and the particle sizes were observed to be around 50 to 130 nm. The results showed that ZnO nanoparticles have displayed inhibition zone of 16 and 13 mm against S. aureus and E. coli respectively. Gram-negative bacteria seemed to be more resistant to ZnO nanoparticles than Gram-positive bacteria.

Matched MeSH terms: Staphylococcus aureus

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