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Fulltext Isolation of lactic acid bacteria strain Staphylococcus piscifermentans from Malaysian traditional fermented shrimp cincaluk

Hajar, S., Hamid, T.H.T.A.

International Food Research Journal, 2013;20(1):125-129.
MyJurnal

Lactic acid bacteria is well known for it uses as starter culture in various fermented food, and it functions as a good natural antimicrobial agent. Cincaluk, a Malaysian fermented shrimp product commonly found in traditional dishes is commonly enriched with LAB. Out of 50 colonies from a local cincaluk, 7 strains were successfully isolated and shown to be positive in lactose utilization and catalase tests. The majority of the isolates from cincaluk showed Gram-positive cocci morphology and belonged to the group Staphyloccoccus spp. By using agar disc diffusion method, the anti-bacterial properties of these isolates (namely isolate 1, 2, 3, 4, 5, 6, and 7) moderately inhibited the growth of several pathogenic strains, i.e., Escherichia coli, Staphylococcus aureus, Salmonella typhimurium and Bacillus subtilis which were used as indicator bacteria. Other than isolates 1, 2, 3 and 5; the 16S rRNA gene for isolate 6 and 7 were successfully amplified. The 16S rRNA gene fragment from isolate 7 was successfully cloned and sequenced. Based on rRNA sequences, both isolates 6 and 7 belonged to the group Staphylococcus piscifermentans, a rare strain previously reported to be specifically isolated exclusive from fish sources.

Matched MeSH terms: Bacillus subtilis
Fulltext Antibacterial agents produced by lactic acid bacteria isolated from Threadfin Salmon and Grass Shrimp

Noordiana N., Fatimah A.B., Mun, A.S.

International Food Research Journal, 2013;20(1):117-124.
MyJurnal

Lactic acid bacteria (LAB) are non-pathogenic bacteria that have an important role in human daily life. LAB produce antimicrobial agents, such as bacteriocins, diacetyl and hydrogen peroxide which help to extend the shelf life of food products. In this study, LAB were isolated from selected seafood; threadfin salmon and grass shrimp. Antibacterial activity of LAB extracts against Salmonella typhimurium, Listeria monocytogenes, Bacillus cereus and Escherichia coli were determined using the disc diffusion method. Three strains of LAB were selected for the characterization of antibacterial agents produced by LAB. The parameters such as pH, heat, incubation period and medium, were analyzed in this experiment. Changes in environmental parameters affected the activity of antibacterial agents. The antibacterial agents produced by LAB were generally heat stable and stable in a wide range of pH levels. However, the inhibition activity of LAB was destroyed with a heat treatment of 121°C, and the antibacterial effect was reduced at a pH of 12, which occurs in most strains. The medium containing NaCl enhanced the
antibacterial activity of P1S1 and P3S3 strains against S. typhimurium, L. monocytogenes and E. coli. Moreover, the antibacterial agents exhibited the greatest inhibition activity at incubation times between 24 and 72 h. The antibacterial activity was reduced after an incubation time of 96 h. The characterization of antibacterial agents aids in the improvement of food products safety

Matched MeSH terms: Bacillus cereus
Fulltext Antarctic bacteria inhibit the growth of pathogens

Wong, C.M.V.L., Chung, H.H., Aisyah, S., Omar, S., Cheah, Y.K., Maria de, L.G., et al.

ASM Science Journal, 2009;3(2):107-112.
MyJurnal

There are relatively little data on bacteria with antimicrobial activities from Antarctic, especially from the South Shetland Islands when compared to the other parts of the world. Hence, this project was set to isolate and characterize bacteria that produce anti-microbial compounds from Greenwich Island (one of the South Shetland Islands), Antarctica. A total of 356 strains of bacteria were isolated from Greenwich Island. They were screened for antimicrobial activities against 13 Gram-negative and one Gram-positive indicator food-borne pathogens. Two out of the 356 Antarctic bacterial strains exhibited an antagonistic effect on the indicator strains, Escherichia coli, Salmonella spp., Klebsiella pneumoniae, Enterobacter cloacae, Vibrio parahaemolyticus and Bacillus cereus. The two Antarctic bacterial strains were designated as SS157 and SR13. Biochemical and 16S rDNA analysis indicated that the strain SS157 was closely related to Pseudomonas congelans while the strain SR13 was closely related to Pseudomonas tremae. The anti-microbial compounds produced by the two Antarctic bacteria were not sensitive to temperature and were not degraded by trypsin or pronase indicating that they were likely to be chemical compounds or antibiotics. Antimicrobial compounds from strains SS157 and SR13 were broad spectrum, and targeted both Gram-positive and negative pathogens.

Matched MeSH terms: Bacillus cereus
Fulltext Screening of selected Malaysian plants against several food borne pathogen bacteria

International Food Research Journal, 2011;18(3):1195-1201.
MyJurnal

This study was conducted to evaluate antimicrobial properties of ethanolic extracts of the leaves of Nephelium lappaceum, Curcuma longa, Cinnamomun cassia, Durio zibethinus, Vitex trifolia, Amaranthus tricolor, Syzygium samarangense and Manihot esculenta. Antibacterial properties of the extracts were studied against fifteen strains of different gram positive and gram negative pathogenic bacteria, including Bacillus cereus, Listeria monocytogenes, Staphylococcus aureus, Vibrio para, and Escherichia coli using the agar disk diffusion method. Among the tested extracts, only Amaranthus tricolor exhibited specific inhibition of one of the tested bacteria; Bacillus cereus. Using the microdilution method, its minimum inhibitory concentration (MIC) value was determined to be 20 mg/mL.

Matched MeSH terms: Bacillus cereus
Fulltext Antioxidant, antimicrobial activity and in-vitro cytotoxicity screening study of Pili nut oil

Zarinah, Z., Maaruf, A.G., Nazaruddin, R., Wong, W.W.W., Xuebing, X.

International Food Research Journal, 2014;21(1):309-316.
MyJurnal

Some vegetable oils contain natural antioxidants such as beta carotene and vitamin E namely alpha tocopherol. The objective of this study was to screening the value of α-tocopherol, β-carotene, antioxidant capacity, antimicrobial activity and toxicological properties of roasted pili nut oil (RPNO) and unroasted pili nut oil (UPNO). The result showed that RPNO contained higher amount of vitamin E and less amount of beta carotene compared to UPNO. RPNO and UPNO scavenged DPPH radicals by 24.66% and 9.52% at concentration of 140 μg/ml. The total phenolic compound (TPC) in UPNO and RPNO were about 19.96 ± 0.52 mg/kg and 12.43 ± 0.69 mg/kg respectively. It was observed that bacteria species exhibited different sensitivities towards RPNO, UPNO, Gentamycin, Ampicillin and Chloramphenicol. Bacillus cereus 14570 was the most sensitive bacterium and all strains of Staphylococcus aureus tested were resistant against both samples RPNO and UPNO. An in vitro toxicological study based on the MTT (3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyl tetrazolium bromide) cytotoxicity assay was also performed. In vitro cytotoxicity indicated that both RPNO and UPNO had no effect against HeLa (cervical cancer cell), MCF-7 (breast cancer cell) and HT-29 (human colon adenocarcinoma cell) cell lines tested.

Matched MeSH terms: Bacillus cereus
Fulltext Stem bark of Canarium Odontophyllum Miq. (dabai) as potential source of antimicrobial agent

Noor Fazdilah Mustari, Zafira Ayushah Zainul Alamin, Noraziah Mohammad Zin, Dayang Fredalina Basri

Jurnal Sains Kesihatan Malaysia, 2017;15(1):1-6.
MyJurnal

The objective of this study was to evaluate the antimicrobial potential of methanol, acetone and distilled water stem
bark extracts from Canarium odontophyllum against Staphylococcus aureus ATCC 25923, Bacillus cereus ATCC 6633,
Escherichia coli ATCC 25932, Pseudomonas aeruginosa ATCC 27853, Acinetobacter baumannii strain sensitive, Candida
albicans ATCC 64677, Candida glabrata ATCC 90028, Aspergillus niger and Fusarium solani M2781. The extracts from
C. odontophyllum stem bark from 3.125 mg/ml to 25 mg/ml were screened against the tested microorganisms using disc
diffusion method. The Minimum inhibitory concentration (MIC) and Minimum Bactericidal Concentration (MBC) of the
extracts against susceptible organisms were determined using microbroth dilution method and streak-plate technique,
respectively. From the antibacterial screening assay, the growth of S. aureus, B. cereus and A. baumannii were inhibited
by methanol extract whereas the acetone extract was capable of inhibiting all the tested microorganisms except E.coli,
F. solani and A. niger. The lowest MIC value for methanol extract was against A. baumannii (0.195 mg/ml) whereas
its MBC value was twice its MIC value (0.391 mg/ml), indicating that methanol extract was bacteriostatic against A.
baumannii. While for acetone extract, S. aureus showed bactericidal effect with equal MIC and MBC values at 0.195 mg/
ml. In conclusion, stem bark of C. odontophyllum has the potential to be the source of antibacterial agent and can be
exploited as an alternative phytoantimicrobial.

Matched MeSH terms: Bacillus cereus
Fulltext Pentocin MQ1: A Novel, Broad-Spectrum, Pore-Forming Bacteriocin From Lactobacillus pentosus CS2 With Quorum Sensing Regulatory Mechanism and Biopreservative Potential

Wayah SB, Philip K

Front Microbiol, 2018;9:564.
PMID: 29636737 DOI: 10.3389/fmicb.2018.00564

Micrococcus luteus, Listeria monocytogenes, and Bacillus cereus are major food-borne pathogenic and spoilage bacteria. Emergence of antibiotic resistance and consumer demand for foods containing less of chemical preservatives led to a search for natural antimicrobials. A study aimed at characterizing, investigating the mechanism of action and regulation of biosynthesis and evaluating the biopreservative potential of pentocin from Lactobacillus pentosus CS2 was conducted. Pentocin MQ1 is a novel bacteriocin isolated from L. pentosus CS2 of coconut shake origin. The purification strategy involved adsorption-desorption of bacteriocin followed by RP-HPLC. It has a molecular weight of 2110.672 Da as determined by MALDI-TOF mass spectrometry and a molar extinction value of 298.82 M-1 cm-1. Pentocin MQ1 is not plasmid-borne and its biosynthesis is regulated by a quorum sensing mechanism. It has a broad spectrum of antibacterial activity, exhibited high chemical, thermal and pH stability but proved sensitive to proteolytic enzymes. It is potent against M. luteus, B. cereus, and L. monocytogenes at micromolar concentrations. It is quick-acting and exhibited a bactericidal mode of action against its targets. Target killing was mediated by pore formation. We report for the first time membrane permeabilization as a mechanism of action of the pentocin from the study against Gram-positive bacteria. Pentocin MQ1 is a cell wall-associated bacteriocin. Application of pentocin MQ1 improved the microbiological quality and extended the shelf life of fresh banana. This is the first report on the biopreservation of banana using bacteriocin. These findings place pentocin MQ1 as a potential biopreservative for further evaluation in food and medical applications.

Matched MeSH terms: Bacillus cereus
Thermal Calcination-Based Production of SnO₂ Nanopowder: An Analysis of SnO₂ Nanoparticle Characteristics and Antibacterial Activities

Al-Hada NM, Kamari HM, Baqer AA, Shaari AH, Saion E

Nanomaterials (Basel), 2018 Apr 17;8(4).
PMID: 29673195 DOI: 10.3390/nano8040250

SnO₂ nanoparticle production using thermal treatment with tin(II) chloride dihydrate and polyvinylpyrrolidone capping agent precursor materials for calcination was investigated. Samples were analyzed using X-ray diffraction (XRD), Scanning Electron Microscopy (SEM), energy dispersive X-ray (EDX), transmission electron microscopy (TEM), Fourier Transform Infrared Spectroscopy (FT-IR), X-ray photoelectron spectroscopy (XPS), diffuse UV-vis reflectance spectra, photoluminescence (PL) spectra and the electron spin resonance (ESR). XRD analysis found tetragonal crystalline structures in the SnO₂ nanoparticles generated through calcination. EDX and FT-IR spectroscopy phase analysis verified the derivation of the Sn and O in the SnO₂ nanoparticle samples from the precursor materials. An average nanoparticle size of 4–15.5 nm was achieved by increasing calcination temperature from 500 °C to 800 °C, as confirmed through TEM. The valence state and surface composition of the resulting nanoparticle were analyzed using XPS. Diffuse UV-vis reflectance spectra were used to evaluate the optical energy gap using the Kubelka-Munk equation. Greater calcination temperature resulted in the energy band gap falling from 3.90 eV to 3.64 eV. PL spectra indicated a positive relationship between particle size and photoluminescence. Magnetic features were investigated through ESR, which revealed the presence of unpaired electrons. The magnetic field resonance decreases along with an increase of the g-factor value as the calcination temperature increased from 500 °C to 800 °C. Finally, Escherichia coli ATCC 25922 Gram (–ve) and Bacillus subtilis UPMC 1175 Gram (+ve) were used for in vitro evaluation of the tin oxide nanoparticle’s antibacterial activity. This work indicated that the zone of inhibition of 22 mm has good antibacterial activity toward the Gram-positive B. subtilis UPMC 1175.

Matched MeSH terms: Bacillus subtilis
Fulltext Candida sp. as a starter culture for cocoa (Theobroma cacao L.) beans fermentation

Mahazar, N. H., Sufian, N. F., Meor Hussin, A. S., Norhayati, H., Mathawan, M., Rukayadi, Y.

International Food Research Journal, 2015;22(5):1783-1787.
MyJurnal

Two cocoa bean fermentation methods (spontaneous fermentation and the use of starter culture) for 7 days fermentation were compared in terms of safety and quality fermented beans. Candida sp. was used as a starter culture in this study. The safety of the fermented cocoa beans were measured by the growth colonies of pathogenic microorganisms namely Bacillus cereus, Escherichia coli, Salmonella sp., Staphylococcus aureus, and Pseudomonas sp., on Bacillus cereus agar, eosin-methylene blue (EMB) agar, xylose lysine deoxycholate (XLD) agar, Baird-Parker agar (BPA), and Pseudomonas agar, respectively. B. cereus, E. coli and Salmonella sp. were early present in both fermentations. Candida sp.-fermentation showed detection of B. cereus at 5.34 log10 CFU/g and absence after 24 hours of fermentation while in spontaneous-fermentation B. cereus was too few to count. Moreover, the log10 E. coli number in Candida sp.-fermentation and spontaneous-fermentation were reduced from 5.72 to 3.66 and from 7.15 to 4.46 on day 1 to day 3, respectively. There were no presences of pathogenic microorganisms on day 5 and day 7 for both fermentations. In term of quality, proximate analysis of spontaneous-fermentation resulted that the content of moisture, ash, fat, crude protein, crude fibre and carbohydrate was 56.47%, 2.32%, 3.17%, 7.02%, 28.14% and 2.88%, meanwhile for the Candida sp.-fermentation was 53.96%, 2.19%, 3.44%, 8.25%, 25.46% and 6.70%, respectively. This study showed that both fermentations are considered to be safe and there is no significant difference in proximate value in fermented cocoa beans from spontaneous-fermentation and Candida sp.-fermentation.

Matched MeSH terms: Bacillus cereus
Secretome analysis of alkaliphilic bacterium Bacillus lehensis G1 in response to pH changes

Ling HL, Rahmat Z, Bakar FDA, Murad AMA, Illias RM

Microbiol Res, 2018 Oct;215:46-54.
PMID: 30172308 DOI: 10.1016/j.micres.2018.06.006

Bacillus lehensis G1 is an alkaliphilic bacterium that is capable of surviving in environments up to pH 11. Secretome related to bacterial acclimation in alkaline environment has been less studied compared to cytoplasmic and membrane proteome. The aim of this study was to gain better understanding of bacterial acclimation to alkaline media through analyzing extracellular proteins of B. lehensis. The pH range for B. lehensis growth was conducted, and two-dimensional electrophoresis and MALDI-TOF/TOF MS analysis were conducted to characterize changes in protein profiling in B. lehensis cultured at pH 8 and pH 11 when compared with those cultured at pH 10 (optimal growth pH). B. lehensis could grow well at pH ranging from 8 to 11 in which the bacteria showed to posses thinner flagella at pH 11. Proteomic analyses demonstrated that five proteins were up-regulated and 13 proteins were down-regulated at pH 8, whereas at pH 11, 14 proteins were up-regulated and 8 were down-regulated. Majority of the differentially expressed proteins were involved in the cell wall, main glycolytic pathways, the metabolism of amino acids and related molecules and some proteins of unknown function. A total of 40 differentially expressed protein spots corresponding to 33 proteins were identified; including GlcNAc-binding protein A, chitinase, endopeptidase lytE, flagellar hook-associated proteins and enolase. These proteins may play important roles in acclimation to alkaline media via reallocation of cell wall structure and changes to cell surface glycolytic enzymes, amino acid metabolism, flagellar hook-associated proteins and chaperones to sustain life under pH-stressed conditions.

Matched MeSH terms: Bacillus
Fulltext Chemical and antibacterial data of synthesized thioureido derivatives

Kadir MA, Ramli R, Yusof MSM, Ismail N, Ngah N, Haris NSH

Data Brief, 2019 Dec;27:104651.
PMID: 31700958 DOI: 10.1016/j.dib.2019.104651

This paper provided comprehensive data on spectroscopic and antibacterial activities of thioureido compounds which are relevant with research article entitled "Synthesis, Spectroscopic Studies and Antibacterial Activity of New Lauroyl Thiourea Amino Acid Derivatives" [1]. Based on the reported study, four new thioureido derivatives, namely 3-(3-dodecanoyl-thioureido)propionic acid (R1), 2-(3-dodecanoyl-thioureido)-3-methyl butyric acid (R2), (3-dodecanoyl-thioureido)acetic acid (R3) and 2-(3-dodecanoyl-thioureido)-3-phenyl propionic acid (R4) were characterized by elemental analysis, Fourier Transform Infrared (FTIR), 1H Nuclear Magnetic Resonance (1H NMR) and 13C Nuclear Magnetic Resonance (13C NMR), and Ultraviolet Visible spectroscopy (UV-Vis). The preliminary results from antibacterial assay which were tested against Gram-positive bacteria such as Bacillus subtilis, Staphylococcus epidermidis, Staphylococcus aureus and Gram-negative bacteria such as Escherichia coli, Salmonella typhimurium are also described.

Matched MeSH terms: Bacillus subtilis
Fulltext Antibacterial activity of biosynthesized gold nanoparticles using biomolecules from Lignosus rhinocerotis and chitosan

Katas H, Lim CS, Nor Azlan AYH, Buang F, Mh Busra MF

Saudi Pharm J, 2019 Feb;27(2):283-292.
PMID: 30766441 DOI: 10.1016/j.jsps.2018.11.010

A simple, cost-effective, and environmentally friendly method is needed for synthesizing metal nanoparticles, including gold nanoparticles (AuNPs). In this study, AuNPs were synthesized with Lignosus rhinocerotis sclerotial extract (LRE) and chitosan (CS) as reducing and stabilizing agents, respectively. Different LRE concentrations from cold and hot water extraction (CWE and HWE, respectively) were used to reduce chloroauric acid (HAuCl4) to form AuNPs. Positively charged chitosan stabilized AuNPs (CS-AuNPs) mediated by LRE exhibited a surface plasmon resonance (SPR) band at 533 nm. The CS-AuNPs synthesized using CWE had a smaller particle size (49.5 ± 6.7-82.4 ± 28.0 nm) compared to that of the HWE samples (80.3 ± 23.4-125.3 ± 41.5 nm), depending on LRE concentration. FTIR results suggested protein and polysaccharides in LRE were the sources of reducing power, reducing gold ions to AuNPs. CS-AuNPs were mostly spherical with higher LRE concentrations, whereas some triangular, pentagonal, irregular, and rod shaped AuNPs were observed at lower LRE concentrations. CS-AuNPs mediated by LRE displayed effective antibacterial activity against gram-negative (Pseudomonas aeruginosa and Escherichia coli) and gram-positive bacteria (Staphylococcus aureus and Bacillus sp.). Thus, the biosynthesized AuNPs using LRE and chitosan provide opportunities for developing stable and eco-friendly nanoparticles with effective antibacterial properties.

Matched MeSH terms: Bacillus
Phytochemical and biological evaluation of Defatted seeds of Jatropha Curcas

Ul Haq MN, Wazir SM, Ullah F, Khan RA, Shah MS, Khatak A

Sains Malaysiana, 2016;45:1435-1442.

In this study, the antimicrobial, antioxidant, phytotoxic and phytochemical properties of defatted seeds of Jatropha curcas were evaluated. A crude methanolic extract of defatted seeds was tested against three fungal strains - Aspergillus niger, Aspergillus flavus and Aspergillus fumigatus - and five bacteria: Escherichia coli and Klebsiella pneumoniae (Gram negative) and Micrococcus luteus, Bacillus subtilis and Staphylococcus aureus (Gram positive). The methanolic extract was diluted in dimethylsulfoxide to final concentrations of 1, 2, 3, 4 and 5 mg/10 mL. The largest zones of inhibition against K. pneumoniae, M. luteus and B. subtilis were achieved using the concentration of 5 mg/10 mL. The concentration of 1 mg/10 mL was most effective against S. aureus and E. coli. In a 1, 1-diphenyl-2-picrylahydrazyl (DPPH) radical scavenging assay, the 5 mg/10 mL concentration of the Jatropha seed extract showed the strongest activity. Higher concentrations of the Jatropha seed extract (10 mg/50 mL and 5 mg/50 mL) significantly inhibited the germination of radish seeds and had negative effects on radish seedling relative water content, shoot length, root length, seedling fresh weight and seedling dry weight (p<0.05). Phytochemical analyses of the defatted seeds detected alkaloids (7.3%), flavonoids (0.39%) and soluble phenolics (mg gallic acid equivalents/g extract). Based on these results, it was inferred that J. curcas seeds contain active ingredients that are effective against pathogenic microbes and therefore could be used to formulate drugs to treat various diseases.

Matched MeSH terms: Bacillus subtilis
Initial screening of mangrove endophytic fungi for antimicrobial compounds and heavy metal biosorption potential

Ling Onn M, Teen Lim P, Aazani Mujahid, Proksch P, Müller M

Sains Malaysiana, 2016;45:1063-1071.

Endophytic fungi provide protection to their host plant and the fungi often produce antimicrobial compounds to aid the host
fighting off pathogens. These bioactive compounds were secondary metabolites which were often produced as waste- or
by-products. In the present study, endophytic fungi isolated from mangrove plants and soils were characterized and their
antimicrobial production and bioremediation potential of heavy metals copper (Cu) and zinc (Zn) were assessed. Twelve
(12) isolated and identified endophytic fungi belonged to seven species; Penicillium, Curvularia, Diaporthe, Aspergillus,
Guignardia, Neusartorya and Eupenicillium. Antimicrobial activities of these 12 fungal endophytes were tested against
Gram negative bacteria; Bacillus subtilis, Staphylococcus aureus, Gram positive bacteria; Escherichia coli and fungi;
Candida albicans and Aspergillus niger among others. Two isolates (related to Guignardia sp. and Neusartoya sp.) showed
strong antimicrobial (and antifungal) activity whereas the rest showed no activity. Compounds were isolated from both
isolates and screened using HPLC. Both isolates displayed chemically very interesting chromatograms as they possessed a
high diversity of basic chemical structures and peaks over a wide range of polarities, with structures similar to Trimeric
catechin and Helenalin among others. For bioremediation assessment, the results showed maximum biosorption capacity
for two isolates related to Curvularia sp. and Neusartorya sp., with the former removing 25 mg Cu/g biomass and the
latter removing 24 mg Zn/g biomass. Our results indicated the potential of mangrove endophytic fungi in producing
bioactive compounds and also highlighted their potential for the treatment of heavy metal-contaminated wastewater.

Matched MeSH terms: Bacillus subtilis
Fulltext Effect of extraction solvents on antioxidant and antimicrobial properties of fenugreek seeds (Trigonella foenum-graecum L.)

Norziah, M.H., Bhat, R., Ahmad, M.

International Food Research Journal, 2015;22(3):1261-1271.
MyJurnal

The present study was aimed to investigate the efficacy of fenugreek seeds as a potential natural source of antioxidants and antimicrobials. Fenugreek seed (FS) extracts were prepared using ethanol (75%), methanol (75%) and water as extraction solvents. Ethanol (E-FSP), methanol (M-FSP), water (W-FSP) and hot water (HW-FSP) extracts were obtained from ground FS, whilst water extract (W-GeFS) was obtained from germinated FS. The results revealed that all extracts of the ground FS exhibited antioxidant and antimicrobial activities and the extractability of bioactive compounds in the presence of water was higher in germinated seeds (W-GeFS). Highest phenolic (156.3 mg GAE/ g) and flavonoid (38.5 mg CE/ g) contents were found in W-GeFS. It also showed the strongest DPPH radical-scavenging activity of 68 % inhibition at a lower concentration (0.06 mg/ ml). In addition, highest vitamin C equivalent antioxidant capacity (143.28 mg vitamin C/ g) with an IC50 value of 42.1 μg/ ml were found in W-GeFS. Based on disc diffusion method, W-GeFS exhibited highest antimicrobial activity against all tested bacterial pathogens (Bacillus subtilis, Staphylococcus aureus, and Escherichia coli). Thus, it can be concluded from the results that W-GeFS extract from germinating fenugreek seeds (W-GeFS) has the potential to be used as a natural source of bioactive compounds with varied applications in food industry especially, for active film packaging purposes to prolong the shelf-life of food products.

Matched MeSH terms: Bacillus subtilis
Distribution, genetic diversity and antimicrobial resistance of clinically important bacteria from the environment of a tertiary hospital in Malaysia

Phoon HYP, Hussin H, Hussain BM, Lim SY, Woon JJ, Er YX, et al.

J Glob Antimicrob Resist, 2018 09;14:132-140.
PMID: 29540306 DOI: 10.1016/j.jgar.2018.02.022

OBJECTIVES: Hospital environments are potential reservoirs of bacteria associated with nosocomial infections. In this study, the distribution of cultivable environmental bacteria of clinical importance from a Malaysian tertiary hospital was determined and their resistotypes and genotypes were investigated.
METHODS: Swab and fluid samples (n=358) from healthcare workers' hands, frequently touched surfaces, medical equipment, patients' immediate surroundings, ward sinks and toilets, and solutions or fluids of 12 selected wards were collected. Biochemical tests, PCR and 16S rRNA sequencing were used for identification following isolation from CHROMagar™ Orientation medium. Clinically important bacteria such as Enterococcus spp., Staphylococcus aureus, Klebsiella pneumoniae, Acinetobacter spp., Pseudomonas aeruginosa and Enterobacter spp. were further characterised by disc diffusion method and rep-PCR.
RESULTS: The 24 Gram-negative and 19 Gram-positive bacteria species identified were widely distributed in the hospital environment. Staphylococci were predominant, followed by Bacillus spp. and P. aeruginosa. Frequently touched surfaces, medical equipment, and ward sinks and toilets were the top three sources of bacterial species. Nine S. aureus, four Acinetobacter spp., one K. pneumoniae and one Enterobacter spp. were multidrug-resistant (MDR). The ESKAPE organisms were genetically diverse and widely dispersed across the hospital wards. A MDR MRSA clone was detected in a surgical ward isolation room.
CONCLUSION: The large variety of cultivable, clinically important bacteria, especially the genetically related MDR S. aureus, K. pneumoniae, Acinetobacter spp. and Enterobacter spp., from various sampling sites indicated that the surfaces and fomites in the hospital were potential exogenous sources of nosocomial infection in the hospital.

Matched MeSH terms: Bacillus
Fulltext Antioxidant and antibacterial properties of green, black, and herbal teas of Camellia sinensis

Chan EW, Soh EY, Tie PP, Law YP

Pharmacognosy Res, 2011 Oct;3(4):266-72.
PMID: 22224051 DOI: 10.4103/0974-8490.89748

BACKGROUND: The role of non-polymeric phenolic (NP) and polymeric tannin (PT) constituents in the antioxidant and antibacterial properties of six brands of green, black, and herbal teas of Camellia sinensis were investigated.
MATERIALS AND METHODS: Total phenolic content (TPC) and ascorbic acid equivalent antioxidant capacity (AEAC) were assessed using the Folin-Ciocalteu and 2,2-diphenyl-1-picrylhydrazyl (DPPH) assays, respectively. Minimum inhibitory dose (MID) against Gram-positive Micrococcus luteus, Staphylococcus aureus, and Bacillus cereus, and Gram-negative. Escherichia coli, Salmonella typhi, and Pseudomonas aeruginosa was assessed using the disc-diffusion method. Teas were extracted with hot water successively three times for one hour each time. The extracts were fractionated using Sephadex LH-20 column chromatography to obtain the NP and PT constituents.
RESULTS: Extraction yields ranged from 12 to 23%. Yields of NP fractions (70-81%) were much higher than those of PT fractions (1-11%), suggesting that the former are the major tea components. Ranking of antioxidant properties of extracts was green tea>black tea>herbal tea. For all six teas, antioxidant properties of PT fractions were significantly higher than extracts and NP fractions. Extracts and fractions of all six teas showed no activity against the three Gram-negative bacteria. Green teas inhibited all three Gram-positive bacteria with S. aureus being the least susceptible. Black and herbal teas inhibited the growth of M. luteus and B. cereus, but not S. aureus. The most potent were the PT fractions of Boh Cameron Highlands and Ho Yan Hor with MID of 0.01 and 0.03 mg/disc against M. luteus.
CONCLUSION: Results suggested that NP constituents are major contributors to the antioxidant and antibacterial properties of teas of C. sinensis. Although PT constituents have stronger antioxidant and antibacterial properties, they constitute only a minor component of the teas.

Matched MeSH terms: Bacillus cereus
Fulltext High Genetic Diversity among Stenotrophomonas maltophilia Isolates from Single Hospital: Nosocomial Outbreaks or Genotypic Profile Changes during Subcultures

Güvenir M, Otlu B, Tunc E, Aktas E, Suer K

Malays J Med Sci, 2018 Mar;25(2):40-49.
PMID: 30918454 DOI: 10.21315/mjms2018.25.2.5

Background: Stenotrophomonas maltophilia is a non-fermentative gram-negative bacillus which is widely recognised as an important nosocomial pathogen causing pneumonia, blood-stream, wound and urinary tract infections, particularly in immunosuppressed patients. The aim of this study was to evaluate a nosocomial outbreak of by S. maltophilia in an intensive care unit of a tertiary hospital and evaluate unexpected multiclonality.
Methods: A total of 11 isolates from respiratory cultures in intensive care unit of a 24 bed tertiary hospital obtained over a one months period and one isolate obtained from the nebuliser during environmental screening were investigated. The bacteria were identified by Phoenix 100 system. The clonal relatedness was evaluated by PFGE and semi-automated repetitive sequence-based PCR. Genotyping tests were repeated for 10 serial subcultures.
Results: PFGE and DiversiLab yielded 10 genotypic profiles for 12 isolates. Four to eight different genotypes were observed from 10 subcultures of the same isolate.
Conclusion: We conclude that, high genetic diversity and supposed multiclonal appearance of the outbreak isolates may be due to changing profiles during subcultures most probably depending on hypermutation.

Matched MeSH terms: Bacillus
Silver(I) complexes of mono- and bidentate N-heterocyclic carbene ligands: synthesis, crystal structures, and in vitro antibacterial and anticancer studies

Haque RA, Choo SY, Budagumpi S, Iqbal MA, Al-Ashraf Abdullah A

Eur J Med Chem, 2015 Jan 27;90:82-92.
PMID: 25461313 DOI: 10.1016/j.ejmech.2014.11.005

A series of benzimidazole-based N-heterocyclic carbene (NHC) proligands {1-benzyl-3-(2-methylbenzyl)-benzimidazolium bromide/hexafluorophosphate (1/4), 1,3-bis(2-methylbenzyl)-benzimidazolium bromide/hexafluorophosphate (2/5) and 1,3-bis(3-(2-methylbenzyl)-benzimidazolium-1-ylmethylbenzene dibromide/dihexafluorophosphate (3/6)} has been synthesized by the successive N-alkylation method. Ag complexes {1-benzyl-3-(2-methylbenzyl)-benzimidazol-2-ylidenesilver(I) hexafluorophosphate (7), 1,3-bis(2-methylbenzyl)-benzimidazol-2-ylidenesilver(I) hexafluorophosphate (8) and 1,3-bis(3-(2-methylbenzyl)-benzimidazol-2-ylidene)-1-ylmethylbenzene disilver(I) dihexafluorophosphate (9)} of NHC ligands have been synthesized by the treatment of benzimidazolium salts with Ag2O at mild reaction conditions. Both, NHC proligands and Ag-NHC complexes have been characterized by (1)H and (13)C{(1)H} NMR and FTIR spectroscopy and elemental analysis technique. Additionally, the structure of the NHC proligand 5 and the mononuclear Ag complexes 7 and 8 has been elucidated by the single crystal X-ray diffraction analysis. Both the complexes exhibit the same general structural motif with linear coordination geometry around the Ag centre having two NHC ligands. Preliminary in vitro antibacterial potentials of reported compounds against a Gram negative (Escherichia coli) and a Gram positive (Bacillus subtilis) bacteria evidenced the higher activity of mononuclear silver(I) complexes. The anticancer studies against the human derived colorectal cancer (HCT 116) and colorectal adenocarcinoma (HT29) cell lines using the MTT assay method, revealed the higher activity of Ag-NHC complexes. The benzimidazolium salts 4-6 and Ag-NHC complexes 7-9 displayed the following IC50 values against the HCT 116 and HT29 cell lines, respectively, 31.8 ± 1.9, 15.2 ± 1.5, 4.8 ± 0.6, 10.5 ± 1.0, 18.7 ± 1.6, 1.20 ± 0.3 and 245.0 ± 4.6, 8.7 ± 0.8, 146.1 ± 3.1, 7.6 ± 0.7, 5.5 ± 0.8, 103.0 ± 2.3 μM.

Matched MeSH terms: Bacillus subtilis/drug effects*
Fulltext Hydroxypropylcellulose as a novel green reservoir for the synthesis, stabilization, and storage of silver nanoparticles

Hussain MA, Shah A, Jantan I, Shah MR, Tahir MN, Ahmad R, et al.

Int J Nanomedicine, 2015;10:2079-88.
PMID: 25844038 DOI: 10.2147/IJN.S75874

Polysaccharides are attracting the vigil eye of researchers in order to design the green synthesis of silver nanoparticles (Ag NPs) of diverse size, shape, and application. We report an environmentally friendly method to synthesize Ag NPs where no physical reaction conditions were employed. Hydroxypropylcellulose (HPC) was used as a template nanoreactor, stabilizer, and capping agent to obtain Ag NPs. Different concentrations of AgNO3 solutions (50 mmol, 75 mmol, and 100 mmol) were mixed with a concentrated aqueous solution of HPC and the progress of the reaction was monitored by noting color changes of the reaction mixture at different reaction times for up to 24 hours. Characteristic ultraviolet-visible spectroscopy (UV/Vis) absorption bands of Ag NPs were observed in the range of 388-452 nm. The morphology of the Ag NPs was studied by scanning electron microscopy, transmission electron microscopy (TEM), and atomic force microscopy. The TEM images confirmed that the size of the Ag NPs was in the range of 25-55 nm. Powder X-ray diffraction studies showed that the crystal phase of the Ag NPs was face-centered cubic. The as-prepared Ag NPs were found to be stable, and no changes in size and morphology were observed after storage in HPC thin films over 1 year, as indicated by UV/Vis spectra. So, the present work furnishes a green and economical strategy for the synthesis and storage of stable Ag NPs. As-synthesized Ag NPs showed significant antimicrobial activity against different bacterial (Escherichia coli, Staphylococcus epidermidis, S. aureus, Bacillus subtilis, Pseudomonas aeruginosa) and fungal strains (Actinomycetes and Aspergillus niger).

Matched MeSH terms: Bacillus subtilis/drug effects

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