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Pyogenic Granuloma Formation Following Ahmed Valve Glaucoma Implant

Chendran P, Seng Fai T, Wan Abdul Halim WH, Md Din N

J Glaucoma, 2019 10;28(10):e162-e164.
PMID: 31368915 DOI: 10.1097/IJG.0000000000001334

Ocular pyogenic granuloma is a benign tumor seen after ocular insult secondary to ocular surgeries, trauma or infection. Although benign, intervention is sometimes necessary. Previous authors have reported pyogenic granuloma formation following oculoplastic surgeries. We report a pyogenic granuloma after an Ahmed glaucoma valve implantation. A 65-year-old gentleman presented with right eye redness associated with pain and swelling ~2 months after Ahmed glaucoma valve implantation. Examination found a sessile growth on the tube extruding puss with signs of endophthalmitis. The glaucoma drainage device was explanted and culture results grew Staphylococcus aureus. This article discusses the formation of pyogenic granuloma on a glaucoma drainage device and its management.

Matched MeSH terms: Staphylococcus aureus/isolation & purification*
Pulsed-field gel electrophoresis of chromosomal DNA of methicillin-resistant Staphylococcus aureus associated with nosocomial infections

Hanifah YA, Hiramatsu K

Malays J Pathol, 1994 Dec;16(2):151-6.
PMID: 9053564

Methicillin-resistant Staphylococcus aureus (MRSA) infection has been endemic in the University Hospital, Kuala Lumpur since the late 1970s. Fifty isolates of MRSA obtained from clinical specimens of patients with nosocomial infections associated with this organism have been studied by pulsed-field gel electrophoresis (PFGE) of its chromosomal DNA fragments to discrimate between strains and to identify the predominant strain. Twenty-one chromosomal patterns were observed which could be further grouped into nine types. The predominant strain was Type 9-b (40% of isolates) found mainly in the Orthopaedic and Surgical Units. Outbreak strains found in the Special Care Nursery were of Type 1, entirely different from those of the surgical ward S2, which were of Type 9-b. Type 8 strains were found mainly at one end of the hospital building where the maternity, paediatric and orthopaedic units were situated. Genomic DNA fingerprinting by PFGE is recommended as a useful and effective tool for the purpose of epidemiological studies of MSRA infections, particularly for nosocomial infections.

Matched MeSH terms: Staphylococcus aureus/genetics*
Pulmonary actinomycosis and skin sinuses

Lee JK

J Paediatr Child Health, 2007 Dec;43(12):854-5.
PMID: 18036023

A 12-year old girl presented with an unusual problem of recurrent discharging multiple skin sinuses on her right anterior and posterior chest wall for a year. There was ipsilateral lower lobe pneumonia and imaging showed multiple abscesses in her lower back muscles bilaterally. A purulent fluid was aspirated from her back muscles and the histology examination showed sulphur granules with gram positive branched filaments. She responded well to the treatment for actinomycosis with penicillin and doxycycline.

Matched MeSH terms: Staphylococcus aureus/isolation & purification
Prominent bactericidal characteristics of silver-copper nanocomposites produced via pulse laser ablation

Alhajj M, Aziz MSA, Huyop F, Salim AA, Sharma S, Ghoshal SK

Biomater Adv, 2022 Nov;142:213136.
PMID: 36206587 DOI: 10.1016/j.bioadv.2022.213136

This paper reports the characterization and antibacterial performance evaluation of some spherical and stable crystalline silver (Ag)/copper (Cu) nanocomposites (Ag-CuNCs) prepared in deionized water (DIW) using pulse laser ablation in liquid (PLAL) method. The influence of various laser fluences (LFs) on the structural, morphological, optical and antibacterial properties of these NCs were determined. The UV-Vis absorbance of these NCs at 403 nm and 595 nm was gradually increased accompanied by a blue shift. XRD patterns disclosed the nucleation of highly crystalline Ag-CuNCs with their face centered cubic lattice structure. TEM images showed the existence of spherical NCs with size range of 3-20 nm and lattice fringe spacing of approximately 0.145 nm. EDX profiles of Ag-CuNCs indicated their high purity. The antibacterial effectiveness of the Ag-CuNCs was evaluated by the inhibition zone diameter (IZD) and optical density (OD600) tests against Gram-negative (Escherichia coli) and Gram-positive (Staphylococcus aureus) bacteria. The proposed NCs revealed the IZD values in the range of 22-26 mm and 20-25 mm when tested against E. coli and S. aureus bacteria, respectively. The Ag-CuNCs prepared at LF of 14.15 J/cm2 revealed the best bactericidal activity. It is established that by controlling the laser fluence the bactericidal effectiveness of the Ag-CuNCs can be tuned.

Matched MeSH terms: Staphylococcus aureus
Profiling of gene expression in methicillin-resistant Staphylococcus aureus in response to cyclo-(L-Val-L-Pro) and chloramphenicol isolated from Streptomyces sp., SUK 25 reveals gene downregulation in multiple biological targets

Zin NM, Al-Shaibani MM, Jalil J, Sukri A, Al-Maleki AR, Sidik NM

Arch Microbiol, 2020 Oct;202(8):2083-2092.
PMID: 32494868 DOI: 10.1007/s00203-020-01896-x

Chloramphenicol (CAP) and cyclo-(L-Val-L-Pro) were previously isolated from Streptomyces sp., SUK 25 which exhibited a high potency against methicillin-resistant Staphylococcus aureus (MRSA). This study aimed to profile gene expression of MRSA treated with CAP and cyclo-(L-Val-L-Pro) compounds using DNA microarray. Treatment of MRSA with CAP resulted in upregulation of genes involved in protein synthesis, suggesting the coping mechanism of MRSA due to the inhibition of protein synthesis effect from CAP. Most upregulated genes in cyclo-(L-Val-L-Pro) were putative genes with unknown functions. Interestingly, genes encoding ribosomal proteins, cell membrane synthesis, DNA metabolism, citric acid cycle and virulence were downregulated in MRSA treated with cyclo-(L-Val-L-Pro) compound, suggesting the efficacy of this compound in targeting multiple biological pathways. Contrary to CAP, with only a single target, cyclo-(L-Val-L-Pro) isolated from this study had multiple antimicrobial targets that can delay antibiotic resistance and hence is a potential antimicrobial agent of MRSA.

Matched MeSH terms: Methicillin-Resistant Staphylococcus aureus/drug effects*; Methicillin-Resistant Staphylococcus aureus/genetics*
Fulltext Prodigiosin inhibits bacterial growth and virulence factors as a potential physiological response to interspecies competition

Yip CH, Mahalingam S, Wan KL, Nathan S

PLoS One, 2021;16(6):e0253445.
PMID: 34161391 DOI: 10.1371/journal.pone.0253445

Prodigiosin, a red linear tripyrrole pigment, has long been recognised for its antimicrobial property. However, the physiological contribution of prodigiosin to the survival of its producing hosts still remains undefined. Hence, the aim of this study was to investigate the biological role of prodigiosin from Serratia marcescens, particularly in microbial competition through its antimicrobial activity, towards the growth and secreted virulence factors of four clinical pathogenic bacteria (methicillin-resistant Staphylococcus aureus (MRSA), Enterococcus faecalis, Salmonella enterica serovar Typhimurium and Pseudomonas aeruginosa) as well as Staphylococcus aureus and Escherichia coli. Prodigiosin was first extracted from S. marcescens and its purity confirmed by absorption spectrum, high performance liquid chromatography (HPLC) and liquid chromatography-tandem mass spectrophotometry (LC-MS/MS). The extracted prodigiosin was antagonistic towards all the tested bacteria. A disc-diffusion assay showed that prodigiosin is more selective towards Gram-positive bacteria and inhibited the growth of MRSA, S. aureus and E. faecalis and Gram-negative E. coli. A minimum inhibitory concentration of 10 μg/μL of prodigiosin was required to inhibit the growth of S. aureus, E. coli and E. faecalis whereas > 10 μg/μL was required to inhibit MRSA growth. We further assessed the effect of prodigiosin towards bacterial virulence factors such as haemolysin and production of protease as well as on biofilm formation. Prodigiosin did not inhibit haemolysis activity of clinically associated bacteria but was able to reduce protease activity for MRSA, E. coli and E. faecalis as well as decrease E. faecalis, Salmonella Typhimurium and E. coli biofilm formation. Results of this study show that in addition to its role in inhibiting bacterial growth, prodigiosin also inhibits the bacterial virulence factor protease production and biofilm formation, two strategies employed by bacteria in response to microbial competition. As clinical pathogens were more resistant to prodigiosin, we propose that prodigiosin is physiologically important for S. marcescens to compete against other bacteria in its natural soil and surface water environments.

Matched MeSH terms: Methicillin-Resistant Staphylococcus aureus/drug effects; Methicillin-Resistant Staphylococcus aureus/growth & development
Fulltext Prevention of cell-surface attachment and reduction of penicillin-binding protein 2a (PBP2a) level in methicillin-resistant Staphylococcus aureus biofilms by Acalypha wilkesiana

Santiago C, Lim KH, Loh HS, Ting KN

BMC Complement Altern Med, 2015;15:79.
PMID: 25880167 DOI: 10.1186/s12906-015-0615-6

Formation of biofilm is known to enhance the virulence of methicillin-resistance Staphylococcus aureus (MRSA), which is associated with persistent infections in hospital settings. The biofilm layer essentially forms a protective barrier encapsulating the bacterial colony and thus reduces the effectiveness of chemotherapeutics. We have isolated 9EA-FC-B bioactive fraction from Acalypha wilkesiana Müll. Arg. that reverses ampicillin resistant in MRSA through inhibition of the antibiotic resistant protein, penicillin-binding protein 2a (PBP2a). In this study, we aimed to investigate the effects of 9EA-FC-B on MRSA biofilm forming capacity.

Matched MeSH terms: Methicillin-Resistant Staphylococcus aureus/drug effects*; Methicillin-Resistant Staphylococcus aureus/metabolism; Methicillin-Resistant Staphylococcus aureus/pathogenicity
Fulltext Prevalence, trend and antimicrobial susceptibility of Methicillin Resistant Staphylococcus aureus in Nigeria: a systematic review

Abubakar U, Sulaiman SAS

J Infect Public Health, 2018;11(6):763-770.
PMID: 29933910 DOI: 10.1016/j.jiph.2018.05.013

BACKGROUND: Evidence to demonstrate the prevalence and trend of Methicillin Resistant Staphylococcus aureus (MRSA) infection in Nigeria is scarce. This review evaluates the prevalence, trend and antimicrobial susceptibility of clinical MRSA isolates reported in published studies.
METHOD: Electronic search (PubMed, Scopus and Google scholar) was conducted using the following search terms: "MRSA OR Methicillin Resistant Staphylococcus aureus AND Nigeria." Reference list of selected studies was scanned to identify more studies. Studies published between 2007 and 2017 that tested at least 30 non-duplicate S. aureus isolates were selected. An independent reviewer extracted data from the studies using a standardized form.
RESULTS: Twelve studies were included in this review. Overall, prevalence of MRSA infection increased from 18.3% (2009) to 42.3% (2013). The prevalence of MRSA infection was less than 50% in all the regions during the period under review. There was a decline in the prevalence of MRSA infection in the North-East (from 12.5% to 8.0%) between 2007 and 2012, and an increase in the South-West (from 20.2% to 47.4%) between 2006 and 2010. Wound, blood and urine specimens had the highest proportion of MRSA isolates. Non-susceptibility of MRSA strains to cotrimoxazole and tetracycline was greater than 85%.
CONCLUSION: Prevalence of MRSA infection in Nigeria is rising, albeit regional variations. Non-susceptibility to commonly prescribed, orally available and inexpensive antibiotics was high. Antimicrobial resistance surveillance system, infection control, and antimicrobial stewardship interventions are recommended.

Matched MeSH terms: Methicillin-Resistant Staphylococcus aureus/drug effects*; Methicillin-Resistant Staphylococcus aureus/isolation & purification
Prevalence, Microbial Etiology and Risk Factors Associated With Healthcare Associated Infections Among End Stage Renal Disease Patients on Renal Replacement Therapy

Abbasi SH, Aftab RA, Mei Lai PS, Lim SK, Nur Zainol Abidin R

J Pharm Pract, 2023 Oct;36(5):1142-1155.
PMID: 35466786 DOI: 10.1177/08971900221094269

End stage renal disease (ESRD) patients on renal replacement therapy (RRT) have an increased risk of morbidity and mortality due to healthcare associated infections (HCAIs). The aim of this study is to determine the prevalence, microbial etiology, and risk factors associated with HCAIs among ESRD patients on RRT. A multicenter, retrospective study was conducted from June to December 2019. ESRD patients with minimum of 6 months on RRT were included, while pregnant patients and patients <18 years were excluded. To reduce the risk of selection bias, all patients were randomly selected using a simple random sampling technique. The prevalence showing the proportion of patients that acquired HCAI since the initiation of dialysis until 2019 was calculated using the European patients' academy (EUPATI) formula. Risk factors were assessed using univariate and multivariate regression analysis. The prevalence of HCAI among ESRD patients was 174/400 (43.5%). Catheter related bloodstream infection (CRBSI) was the most common infection [64(36.8%)], followed by peritonitis [45(25.8%)] and pneumonia [37(21.2%)]. Out of 382 total pathogens identified, 204 (53.4%) were Gram positive and 162 (42.4%) were Gram negative. Both methicillin sensitive staphylococcus aureus (MSSA) and methicillin resistant staphylococcus aureus (MRSA) showed statistically significant associations (p<0.05) with CRBSI. Use of multiple accesses, increased blood sugar levels, low serum sodium levels and higher CRP concentration increased the occurrence of HCAIs. The burden of HCAIs among the patients undergoing RRT is high. Preventive strategies and optimum empirical therapy of antibiotics should be used to reduce the risk of these infections among ESRD patients.

Matched MeSH terms: Methicillin-Resistant Staphylococcus aureus*
Prevalence of mupirocin resistance in methicillin-resistant Staphylococcus aureus strains isolated from a Malaysian hospital

Lim KT, Hanifah YA, Mohd Yusof MY, Thong KL

Jpn J Infect Dis, 2010 Jul;63(4):286-9.
PMID: 20657072

Mupirocin is used topically to treat skin infection caused by methicillin-resistant Staphylococcus aureus (MRSA). One hundred eighty-eight strains (isolated in 2003, 2004, 2007, and 2008) were tested for mupirocin susceptibility using disk diffusion method and minimum inhibitory concentration (MIC). Mupirocin resistance was detected in 10 (5%) strains with 2 of them showing MIC of 256 mg/l. PCR detection using gene-specific primers showed that all 10 mupirocin-resistant strains harbored ileS2 gene whereas mupA gene was detected in 2 mupirocin-resistant strains with MIC of 256 mg/l. Amplification of agr grouping and SCCmec typing showed that all 10 strains were agr group I and SCCmec type III. Sequence analysis of region X of the spa gene yielded 4 distinct spa types (t037, t363, t421, and t6405) which were clonally related. In conclusion, the rate of mupirocin resistance in Malaysia is still low but is much higher than previous reports in Malaysia.

Matched MeSH terms: Methicillin-Resistant Staphylococcus aureus/drug effects*; Methicillin-Resistant Staphylococcus aureus/isolation & purification
Prevalence of methicillin-resistant Staphylococcus aureus and its antibiotic susceptibility pattern in a tertiary care hospital

Tiwari S, Sahu M, Rautaraya B, Karuna T, Mishra SR, Bhattacharya S

J Indian Med Assoc, 2011 Nov;109(11):800-1.
PMID: 22666934

Methicillin-resistant Staphylococcus aureus (MRSA) emerged as a nosocomial pathogen in early 1960s, causing Increasing number of outbreaks in 19708, first reported in a teaching hospital in Malaysia in 1972, causing increased mortality, morbidity, and healthcare costs. Aim of this study is to screen out MRSA from various clinical samples and to see their antibiotic susceptibility pattern. From May 2008 to May 2009, 204 S aureus strains were isolated, out of which 114 (55.8%) were MRSA, and rest methicillin-sensitive Staphylococcus aureus (MSSA). Most of the MRSA strains were obtained from pus (45%) followed by urine (20.5%). Frequency of isolating MRSA were maximum in catheter tip (80%) followed by blood (66.7%) and pus (58.7%). MRSA strains were showing 100% sensitivity to vancomycin and Iinezolid, whereas 92.9% to teicoplanin. Therefore it is concluded that antibiotics other than vancomycin can be used as anti-MRSA agents after sensitivity test, as well as irrational and indiscriminate use of antibiotics can be avoided.

Matched MeSH terms: Methicillin-Resistant Staphylococcus aureus/drug effects*; Methicillin-Resistant Staphylococcus aureus/isolation & purification
Fulltext Prevalence of methicillin-resistant Staphylococcus aureus (MRSA) infection and the molecular characteristics of MRSA bacteraemia over a two-year period in a tertiary teaching hospital in Malaysia

Sit PS, Teh CS, Idris N, Sam IC, Syed Omar SF, Sulaiman H, et al.

BMC Infect Dis, 2017 04 13;17(1):274.
PMID: 28407796 DOI: 10.1186/s12879-017-2384-y

BACKGROUND: Methicillin-resistant Staphylococcus aureus (MRSA) is an established pathogen that causes hospital- and community-acquired infections worldwide. The prevalence rate of MRSA infections were reported to be the highest in Asia. As there is limited epidemiological study being done in Malaysia, this study aimed to determine the prevalence of MRSA infection and the molecular characteristics of MRSA bacteraemia.
METHODS: Two hundred and nine MRSA strains from year 2011 to 2012 were collected from a tertiary teaching hospital in Malaysia. The strains were characterized by antimicrobial susceptibility testing, staphylococcal cassette chromosome mec (SCCmec) typing, detection of Panton-Valentine leukocidin (PVL) gene, multilocus sequence typing (MLST) and pulsed-field gel electrophoresis (PFGE). Patient's demographic and clinical data were collected and correlated with molecular data by statistical analysis.
RESULTS: Male gender and patient >50 years of age (p

Matched MeSH terms: Methicillin-Resistant Staphylococcus aureus/genetics*
Fulltext Prevalence of adhesion and regulation of biofilm-related genes in different clones of Staphylococcus aureus

Atshan SS, Nor Shamsudin M, Sekawi Z, Lung LT, Hamat RA, Karunanidhi A, et al.

J Biomed Biotechnol, 2012;2012:976972.
PMID: 22701309 DOI: 10.1155/2012/976972

Clinical information about genotypically different clones of biofilm-producing Staphylococcus aureus is largely unknown. We examined whether different clones of methicillin-sensitive and methicillin-resistant S. aureus (MSSA and MRSA) differ with respect to staphylococcal microbial surface components recognizing adhesive matrix molecules (MSCRAMMs) in biofilm formation. The study used 60 different types of spa and determined the phenotypes, the prevalence of the 13 MSCRAMM, and biofilm genes for each clone. The current investigation was carried out using a modified Congo red agar (MCRA), a microtiter plate assay (MPA), polymerase chain reaction (PCR), and reverse transcriptase polymerase chain reaction (RT-PCR). Clones belonging to the same spa type were found to have similar properties in adheringto the polystyrene microtiter plate surface. However, their ability to produce slime on MCRA medium was different. PCR experiments showed that 60 clones of MSSA and MRSA were positive for 5 genes (out of 9 MSCRAMM genes). icaADBC genes were found to be present in all the 60 clones tested indicating a high prevalence, and these genes were equally distributed among the clones associated with MSSA and those with MRSA. The prevalence of other MSCRAMM genes among MSSA and MRSA clones was found to be variable. MRSA and MSSA gene expression (MSCRAMM and icaADBC) was confirmed by RT-PCR.

Matched MeSH terms: Methicillin-Resistant Staphylococcus aureus/genetics*; Methicillin-Resistant Staphylococcus aureus/growth & development; Methicillin-Resistant Staphylococcus aureus/pathogenicity
Fulltext Prevalence of Staphylococcus aureus carriage by young Malaysian footballers during indoor training

William JL, Radu S, Aziz SA, Rahim RA, Cheah YK, Liwan A, et al.

Br J Sports Med, 2004 Feb;38(1):12-4.
PMID: 14751938

BACKGROUND: Research has shown that athletes are carriers of Staphylococcus aureus during physical activity.
OBJECTIVE: To estimate the mean total plate count of S aureus carried by footballers before and after training at an indoor venue.
METHODS: Forty Malay and 20 Indian students volunteered to participate. There was also a control group consisting of 40 Malay and 20 Indian students who were not active. The experimental group were active footballers who had played at school or club level. The subjects were healthy and free of skin infection. The experiment was divided into three sessions, with 20 subjects present at each. At each session, the subjects trained for one hour. Swabs were taken from the skin, nose, and ear before and after training. For the control group, swabs were taken only once from the skin, nose, and ear. The swabs were subjected to biochemical tests and then streaked and cultured aerobically in Baird Parker agar plates for 24 hours at 37 degrees C. Black colonies with a clear zone were presumed to be S aureus, and the mean total plate count of the colonies was estimated. Gram staining, catalase, coagulase slide, coagulase tube, acetoin production, o-nitrophenyl beta-D-galactopyranoside (ONPG), and mannitol fermentation tests were used to confirm the colonies as S aureus. A haemolysin test was conducted with human blood to confirm haemolytic activity.
RESULTS: All subjects in the experimental group were carrying S aureus both before and after training. The estimated mean total counts of colonies from the skin, ear, and nose for the Malays before training were 33, 71, and 312 respectively. Counts after training were 21, 44, and 452 respectively. The results for the Indians were 72, 80, and 309 respectively before training and 55, 200, and 466 respectively after training. The positive results for Gram staining, catalase, coagulase slide, coagulase tube, acetoin production, ONPG, and mannitol fermentation tests were 100%, 96%, 95%, 95%, 93%, 93%, and 90% respectively. All subjects in the control group were also carrying S aureus.
CONCLUSIONS: All of the players were carriers of S aureus during training. The decrease in total count from the skin for both races may be due to lysozyme activity lysing the bacterial cells. Contamination of the environment with these bacteria may have increased the estimated total plate count in the nose. The experimental group face a higher risk of infection because of lower immunity during training and higher rate of injuries compared with the control group.

Matched MeSH terms: Staphylococcus aureus/isolation & purification
Fulltext Prevalence of ST9 methicillin-resistant Staphylococcus aureus among pigs and pig handlers in Malaysia

Neela V, Mohd Zafrul A, Mariana NS, van Belkum A, Liew YK, Rad EG

J Clin Microbiol, 2009 Dec;47(12):4138-40.
PMID: 19812280 DOI: 10.1128/JCM.01363-09

Methicillin-resistant Staphylococcus aureus (MRSA) of sequence type 398 (ST398) has frequently been detected in pigs and pig handlers. However, in Malaysia, sampling 360 pigs and 90 pig handlers from 30 farms identified novel ST9-spa type t4358-staphylococcal cassette chromosome mec type V MRSA strains that were found to transiently colonize more than 1% of pigs and 5.5% of pig handlers.

Matched MeSH terms: Methicillin-Resistant Staphylococcus aureus/classification; Methicillin-Resistant Staphylococcus aureus/genetics; Methicillin-Resistant Staphylococcus aureus/isolation & purification*
Fulltext Prevalence of Panton-Valentine leukocidin genes among carriage and invasive Staphylococcus aureus isolates in Malaysia

Neela V, Ehsanollah GR, Zamberi S, Van Belkum A, Mariana NS

Int J Infect Dis, 2009 May;13(3):e131-2.
PMID: 18955004 DOI: 10.1016/j.ijid.2008.07.009
Matched MeSH terms: Staphylococcus aureus/genetics*; Staphylococcus aureus/isolation & purification
Fulltext Preparation and properties of poly(vinyl alcohol)/chitosan blend bionanocomposites reinforced with cellulose nanocrystals/ZnO-Ag multifunctional nanosized filler

Azizi S, Ahmad MB, Hussein MZ, Ibrahim NA, Namvar F

Int J Nanomedicine, 2014;9:1909-17.
PMID: 24790433 DOI: 10.2147/IJN.S60274

A series of novel bionanocomposites were cast using different contents of zinc oxide-silver nanoparticles (ZnO-AgNPs) stabilized by cellulose nanocrystals (CNC) as multifunctional nanosized fillers in poly(vinyl alcohol)/chitosan (PVA/Cs) matrices. The morphological structure, mechanical properties, ultraviolet-visible absorption, and antimicrobial properties of the prepared films were investigated as a function of their CNC/ZnO-AgNP content and compared with PVA/chitosan/CNC bionanocomposite films. X-ray diffraction and field emission scanning electron microscopic analyses showed that the CNC/ZnO-AgNPs were homogeneously dispersed in the PVA/Cs matrix and the crystallinity increased with increasing nanosized filler content. Compared with pure PVA/Cs, the tensile strength and modulus in the films increased from 0.055 to 0.205 GPa and from 0.395 to 1.20 GPa, respectively. Ultraviolet and visible light can be efficiently absorbed by incorporating ZnO-AgNPs into a PVA/Cs matrix, suggesting that these bionanocomposite films show good visibility and ultraviolet-shielding effects. The bionanocomposite films had excellent antimicrobial properties, killing both Gram-negative Salmonella choleraesuis and Gram-positive Staphylococcus aureus. The enhanced physical properties achieved by incorporating CNC/ZnO-AgNPs could be beneficial in various applications.

Matched MeSH terms: Staphylococcus aureus/drug effects
Preparation and photodynamic bactericidal effects of curcumin-β-cyclodextrin complex

Lai D, Zhou A, Tan BK, Tang Y, Sarah Hamzah S, Zhang Z, et al.

Food Chem, 2021 Nov 01;361:130117.
PMID: 34058659 DOI: 10.1016/j.foodchem.2021.130117

To overcome the poor water solubility of curcumin, a curcumin-β-cyclodextrin (Cur-β-CD) complex was prepared as a novel photosensitizer. Fourier-transform infrared spectroscopy (FT-IR), differential scanning calorimetry (DSC), and X-ray diffraction (XRD) were used to verify the formation of Cur-β-CD. Furthermore, the ROS generation capacity and photodynamic bactericidal effect were measured to confirm this Cur-β-CD complex kept photodynamic activity of curcumin. The result showed Cur-β-CD could effectively generate ROS upon blue-light irradiation. The plate count assay demonstrated Cur-β-CD complex possess desirable photodynamic antibacterial effect against food-borne pathogens including Staphylococcus aureus, Listeria monocytogenes and Escherichia coli. The cell morphology determined by scanning electron microscope (SEM) and transmission electron microscope (TEM) showed Cur-β-CD could cause cell deformation, surface collapse and cell structure damage of the bacteria, resulting in the leakage of cytoplasmic; while agarose gel electrophoresis and SDS-PAGE further illustrated the inactivation mechanisms by Cur-β-CD involve bacterial DNA damage and protein degradation.

Matched MeSH terms: Staphylococcus aureus/drug effects
Fulltext Preliminary Screening of Antibacterial Activity Using Crude Extracts of Hibiscus rosa sinensis

Arullappan S, Zakaria Z, Basri DF

Trop Life Sci Res, 2009 Dec;20(2):109-18.
PMID: 24575183 MyJurnal

Hibiscus rosa sinensis, a member of the Malvaceae family, is widely cultivated in the tropics as an ornamental plant. It is often planted as a fence or hedge plant, and has several forms of flowers with varying colours. It is also used in traditional medicine to induce abortion, ease menstrual cramps, assist in childbirth and relieve headache, fever and inflammation. In this study, we evaluated the antibacterial activity of H. rosa sinesis extract using a disc diffusion method. Crude petroleum ether extract, ethyl acetate extract and methanol extract from the leaves, stems and flowers of the plant were prepared using a cold extraction technique. These extracts were tested at concentrations ranging from 4 mg/disc to 0.017 mg/disc against methicillin-resistant Staphylococcus aureus (MRSA), Staphylococcus aureus, Escherichia coli, Pseudomonas aeruginosa and Klebsiella pneumonia. The petroleum ether extract from the leaves, stems and flowers and methanol extract from the leaves showed inhibition zones with diameters > 12 mm against MRSA. Overall, the petroleum ether extract from flowers at concentrations of 4 mg/disc and 2 mg/disc displayed the strongest inhibition zones of 18.6 ± 2.85 mm and 18.5 ± 0.29 mm, respectively, as compared to vancomycin (30 μg/ml), which did not differ significantly from the 18.0 ± 0.10 mm size of the vancomycin (30 μg/ml) inhibition zone (p < 0.05). In conclusion, H. rosa sinensis extract is a potential antibacterial agent for treating MRSA infection.

Matched MeSH terms: Staphylococcus aureus; Methicillin-Resistant Staphylococcus aureus
Fulltext Preliminary Insight of Pyrrolylated-Chalcones as New Anti-Methicillin-Resistant Staphylococcus aureus (Anti-MRSA) Agents

Gunasekharan M, Choi TI, Rukayadi Y, Mohammad Latif MA, Karunakaran T, Mohd Faudzi SM, et al.

Molecules, 2021 Sep 01;26(17).
PMID: 34500755 DOI: 10.3390/molecules26175314

Bacterial infections are regarded as one of the leading causes of fatal morbidity and death in patients infected with diseases. The ability of microorganisms, particularly methicillin-resistant Staphylococcus aureus (MRSA), to develop resistance to current drugs has evoked the need for a continuous search for new drugs with better efficacies. Hence, a series of non-PAINS associated pyrrolylated-chalcones (1-15) were synthesized and evaluated for their potency against MRSA. The hydroxyl-containing compounds (8, 9, and 10) showed the most significant anti-MRSA efficiency, with the MIC and MBC values ranging from 0.08 to 0.70 mg/mL and 0.16 to 1.88 mg/mL, respectively. The time-kill curve and SEM analyses exhibited bacterial cell death within four hours after exposure to 9, suggesting its bactericidal properties. Furthermore, the docking simulation between 9 and penicillin-binding protein 2a (PBP2a, PDB ID: 6Q9N) suggests a relatively similar bonding interaction to the standard drug with a binding affinity score of -7.0 kcal/mol. Moreover, the zebrafish model showed no toxic effects in the normal embryonic development, blood vessel formation, and apoptosis when exposed to up to 40 µM of compound 9. The overall results suggest that the pyrrolylated-chalcones may be considered as a potential inhibitor in the design of new anti-MRSA agents.

Matched MeSH terms: Methicillin-Resistant Staphylococcus aureus/drug effects*

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