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  1. An agar diffusion study comparing the antimicrobial activity of Nanoseal with some other endodontic sealers
    Aal-Saraj AB, Ariffin Z, Masudi SM
    Aust Endod J, 2012 Aug;38(2):60-3.
    PMID: 22827817 DOI: 10.1111/j.1747-4477.2010.00241.x
    The aim of this study was to evaluate the antimicrobial activity of a new experimental nano-hydroxyapatite epoxy resin-based sealer (Nanoseal) with several other commercially available sealers; AH26, Tubliseal, Sealapex and Roekoseal against Enterococcus faecalis, Pseudomonas aeruginosa, Streptococcus mutans, Streptococcus sobrinus and Escherichia coli for up to 7 days. Agar diffusion was used in this study. Fifty Muller-Hinton agar plates were prepared and divided into five experimental groups (n = 10), for each micro-organism. Another 10 agar plates were used as positive and negative controls. Endodontic sealers were tested against each micro-organism. Inhibition zones produced were recorded. The results of this study showed that all test materials exhibited inhibition zones towards the tested micro-organisms for 7 days except for Roekoseal, which showed no inhibition zones. Nanoseal and AH26 exhibited similar zones of inhibition. Significant difference was found between Nanoseal and the other tested sealers (P < 0.001).
    Matched MeSH terms: Bacteria, Anaerobic/drug effects*
  2. Isolation and identification of bacterial populations of zoonotic importance from captive non-venomous snakes in Malaysia
    Abba Y, Ilyasu YM, Noordin MM
    Microb Pathog, 2017 Jul;108:49-54.
    PMID: 28478198 DOI: 10.1016/j.micpath.2017.04.038
    AIM: Captivity of non-venomous snakes such as python and boa are common in zoos, aquariums and as pets in households. Poor captivity conditions expose these reptiles to numerous pathogens which may result in disease conditions. The purpose of this study was to investigate the common bacteria isolated from necropsied captive snakes in Malaysia over a five year period.

    MATERIALS AND METHODS: A total of 27 snake carcasses presented for necropsy at the Universiti Putra Malaysia (UPM) were used in this survey. Samples were aseptically obtained at necropsy from different organs/tissues (lung, liver, heart, kindey, oesophagus, lymph node, stomach, spinal cord, spleen, intestine) and cultured onto 5% blood and McConkey agar, respectively. Gram staining, morphological evaluation and biochemical test such as oxidase, catalase and coagulase were used to tentatively identify the presumptive bacterial isolates.

    RESULTS: Pythons had the highest number of cases (81.3%) followed by anaconda (14.8%) and boa (3.7%). Mixed infection accounted for 81.5% in all snakes and was highest in pythons (63%). However, single infection was only observed in pythons (18.5%). A total of 82.7%, 95.4% and 100% of the bacterial isolates from python, anaconda and boa, respectively were gram negative. Aeromonas spp was the most frequently isolated bacteria in pythons and anaconda with incidences of 25 (18%) and 8 (36.6%) with no difference (p > 0.05) in incidence, respectively, while Salmonella spp was the most frequently isolated in boa and significantly higher (p Bacteria species were most frequently isolated from the kidney of pythons 35 (25.2%), intestines of anacondas 11 (50%) and stomach of boa 3 (30%).

    CONCLUSION: This study showed that captive pythons harbored more bacterial species than anaconda or boa. Most of the bacterial species isolated from these snakes have public health importance and have been incriminated in human infections worldwide.

    Matched MeSH terms: Bacteria/classification*; Bacteria/isolation & purification*; Bacteria/pathogenicity
  3. Fulltext An intriguing approach toward antibacterial activity of green synthesized Rutin-templated mesoporous silica nanoparticles decorated with nanosilver
    Abbasi M, Gholizadeh R, Kasaee SR, Vaez A, Chelliapan S, Fadhil Al-Qaim F, et al.
    Sci Rep, 2023 Apr 12;13(1):5987.
    PMID: 37046068 DOI: 10.1038/s41598-023-33095-1
    In recent years, mesoporous silica nanoparticles (MSNs) have been applied in various biomedicine fields like bioimaging, drug delivery, and antibacterial alternatives. MSNs could be manufactured through green synthetic methods as environmentally friendly and sustainable synthesis approaches, to improve physiochemical characteristics for biomedical applications. In the present research, we used Rutin (Ru) extract, a biocompatible flavonoid, as the reducing agent and nonsurfactant template for the green synthesis of Ag-decorated MSNs. Transmission electron microscopy (TEM), zeta-potential, x-ray powder diffraction (XRD), fourier transform infrared (FTIR) spectroscopy analysis, scanning electron microscopy (SEM), brunauer-emmett-teller (BET) analysis, and energy-dispersive system (EDS) spectroscopy were used to evaluate the Ag-decorated MSNs physical characteristics. The antimicrobial properties were evaluated against Staphylococcus aureus (S. aureus), Escherichia coli (E. coli), and also different types of candida. The cytotoxicity test was performed by using the MTT assay. Based on the findings, the significant antimicrobial efficacy of Ru-Ag-decorated MSNs against both gram positive and gram negative bacteria and different types of fungi was detected as well as acceptable safety and low cytotoxicity even at lower concentrations. Our results have given a straightforward and cost-effective method for fabricating biodegradable Ag-decorated MSNs. The applications of these MSNs in the domains of biomedicine appear to be promising.
    Matched MeSH terms: Gram-Negative Bacteria; Gram-Positive Bacteria
  4. Synthesis of 2-Furyl[(4-aralkyl)-1-piperazinyl]methanone derivatives as suitable antibacterial agents with mild cytotoxicity
    Abbasi MA, Nazeer MM, Rehman A, Siddiqui SZ, Hussain G, Shah SA, et al.
    Pak J Pharm Sci, 2018 Nov;31(6):2477-2485.
    PMID: 30473521
    The aim of the present research work was synthesis of some 2-furyl[(4-aralkyl)-1-piperazinyl]methanone derivatives and to ascertain their antibacterial potential. The cytotoxicity of these molecules was also checked to find out their utility as possible therapeutic agents. The synthesis was initiated by reacting furyl(-1-piperazinyl)methanone (1) in N,N-dimethylformamide (DMF) and lithium hydride with different aralkyl halides (2a-j) to afford 2-furyl[(4-aralkyl)-1-piperazinyl]methanone derivatives (3a-j). The structural confirmation of all the synthesized compounds was done by IR, EI-MS, 1H-NMR and 13C-NMR spectral techniques and through elemental analysis. The results of in vitro antibacterial activity of all the synthesized compounds were screened against Gram-negative (S. typhi, E. coli, P. aeruginosa) and Gram-positive (B. subtilis, S. aureus) bacteria and were found to be decent inhibitors. Amongst the synthesized molecules, 3e showed lowest minimum inhibitory concentration MIC = 7.52±0.μg/mL against S. Typhi, credibly due to the presence of 2-bromobenzyl group, relative to the reference standard, ciprofloxacin, having MIC = 7.45±0.58μg/mL.
    Matched MeSH terms: Gram-Negative Bacteria/drug effects*; Gram-Negative Bacteria/growth & development; Gram-Positive Bacteria/drug effects*; Gram-Positive Bacteria/growth & development
  5. REPORT - Synthesis of promising antibacterial and antifungal agents: 2-[[(4-Chlorophenyl)sulfonyl](2,3-dihydro-1,4-benzodioxin-6-yl)amino]-N-(un/substituted-phenyl)acetamides
    Abbasi MA, Irshad M, Aziz-Ur-Rehman -, Siddiqui SZ, Nazir M, Ali Shah SA, et al.
    Pak J Pharm Sci, 2020 Sep;33(5):2161-2170.
    PMID: 33824125
    In the presented work, 2,3-dihydro-1,4-benzodioxin-6-amine (1) was reacted with 4-chlorobenzenesulfonyl chloride (2) in presence of aqueous basic aqueous medium to obtain 4-chloro-N-(2,3-dihydro-1,4-benzodioxin-6-yl)benzenesulfonamide (3). In parallel, various un/substituted anilines (4a-l) were treated with bromoacetyl bromide (5) in basified aqueous medium to obtain corresponding 2-bromo-N-(un/substituted)phenylacetamides (6a-l) as electrophiles. Then the compound 3 was finally reacted with these electrophiles, 6a-l, in dimethylformamide (DMF) as solvent and lithium hydride as base and activator to synthesize a variety of 2-[[(4-chlorophenyl)sulfonyl](2,3-dihydro-1,4-benzodioxin-6-yl)amino]-N-(un/substituted)phenylacetamides (7a-l). The synthesized compounds were corroborated by IR, 1H-NMR and EI-MS spectral data for structural confirmations. These molecules were then evaluated for their antimicrobial and antifungal activities along with their %age hemolytic activity. Some compounds were found to have suitable antibacterial and antifungal potential, especially the compound 2-[[(4-chlorophenyl)sulfonyl](2,3-dihydro-1,4-benzodioxin-6-yl)amino]-N-(3,5-dimethylphenyl)acetamide (7l) exhibited good antimicrobial potential with low value of % hemolytic activity.
    Matched MeSH terms: Anti-Bacterial Agents/chemical synthesis*; Anti-Bacterial Agents/pharmacology*; Anti-Bacterial Agents/toxicity; Bacteria/drug effects; Bacteria/growth & development
  6. Fulltext In vitro assessment of Pediococcus acidilactici Kp10 for its potential use in the food industry
    Abbasiliasi S, Tan JS, Bashokouh F, Ibrahim TAT, Mustafa S, Vakhshiteh F, et al.
    BMC Microbiol, 2017 May 23;17(1):121.
    PMID: 28535747 DOI: 10.1186/s12866-017-1000-z
    BACKGROUND: Selection of a microbial strain for the incorporation into food products requires in vitro and in vivo evaluations. A bacteriocin-producing lactic acid bacterium (LAB), Pediococcus acidilactici Kp10, isolated from a traditional dried curd was assessed in vitro for its beneficial properties as a potential probiotic and starter culture. The inhibitory spectra of the bacterial strain against different gram-positive and gram-negative bacteria, its cell surface hydrophobicity and resistance to phenol, its haemolytic, amylolytic and proteolytic activities, ability to produce acid and coagulate milk together with its enzymatic characteristics and adhesion property were all evaluated in vitro.

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

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

    Matched MeSH terms: Gram-Negative Bacteria/drug effects; Gram-Positive Bacteria/drug effects
  7. Characterization and effect on skin hydration of engkabang-based emulsions
    Abd Gani SS, Basri M, Rahman MB, Kassim A, Abd Rahman RN, Salleh AB, et al.
    Biosci Biotechnol Biochem, 2010;74(6):1188-93.
    PMID: 20530909
    Formulations containing engkabang fat and engkabang fat esters, F10 and E15 respectively were prepared using a high-shear homogenizer, followed by a high-pressure homogenizer. Both formulations were stable at room temperature, at 45 degrees C, and after undergoing freeze-thaw cycles. The particle sizes of F10 and E15 after high pressure were 115.75 nm and 148.41 nm respectively. The zeta potentials of F10 and E15 were -36.4 mV and -48.8 mV respectively, while, the pH values of F10 and E15 were 5.59 and 5.81 respectively. The rheology of F10 and E15 showed thixotropy and pseudoplastic behavior respectively. There were no bacteria or fungal growths in the samples. The short-term moisturizing effect on 20 subjects analyzed by analysis of variance (ANOVA), gave p-values of 7.35 x 10(-12) and 2.77 x 10(-15) for F10 and E15 respectively. The hydration of the skins increased after application of F10 and E15 with p-value below 0.05.
    Matched MeSH terms: Bacteria/drug effects
  8. Bacterial profiling of head lice isolated from the Orang Asli: A first report in Malaysia
    Abd Majid MA, Khoo JJ, Lim FS, Khor CS, Loong SK, Low VL, et al.
    Trop Biomed, 2020 Dec 01;37(4):884-895.
    PMID: 33612742 DOI: 10.47665/tb.37.4.884
    This study was carried out to determine from bacterial profiling to the bacterial profiles of head lice among the Orang Asli communities. The head lice were collected from Orang Asli community volunteers. The surface sterilized head lice pools were subjected to genomic DNA extraction while next generation sequencing of the 16S rRNA gene was performed using the Illumina MiSeq platform. Six female and three male head lice identified as Pediculus humanus capitis were collected. A total of 111 368 number of NGS sequencing reads were recorded while another 223 bacterial taxa sequences were obtained. Symbiotic bacteria showed the highest number of reads, with Arsenophonus and Rhodococcus sequences being the most abundant genera in the female and male samples, respectively. The female head lice contained a more distinct microbial diversity. Amongst the pathogenic bacterial species sequences noted were the methicillin-resistant Staphylococcus aureus, Streptobacillus moniliformis, Haemophilus influenzae, Bordetella pertussis and Acinetobacter baumannii. The 16S rRNA genome sequencing revealed a number of rare and pathogenic bacterial species within the head lice of the Orang Asli. The socio-economic practices of the community which involved forest foraging and hunting, and their poor living conditions potentially facilitated the transmission of zoonotic bacterial pathogens, including those found within the head lice. Hence, there is the possibility that the head lice could serve as vectors for the transmission of pathogenic bacteria. This study highlighted the diverse microbial community found within the head lice's gut of the Orang Asli, with the detection of multiple rare and pathogenic bacteria capable of causing severe infections.
    Matched MeSH terms: Bacteria/classification*; Bacteria/isolation & purification; DNA, Bacterial/genetics
  9. Fulltext In Vitro Influence of ZnO, CrZnO, RuZnO, and BaZnO Nanomaterials on Bacterial Growth
    Abdallah EM, Modwi A, Al-Mijalli SH, Mohammed AE, Idriss H, Omar AS, et al.
    Molecules, 2022 Nov 28;27(23).
    PMID: 36500402 DOI: 10.3390/molecules27238309
    In this work, ZnO, CrZnO, RuZnO, and BaZnO nanomaterials were synthesized and characterized in order to study their antibacterial activity. The agar well diffusion, minimum inhibitory concentration (MIC), and minimum bactericidal concentration (MBC) assays were used to determine the antibacterial activity of the fabricated nanomaterials against Staphylococcus aureus ATCC 29213, Escherichia coli ATCC35218, Klebsiella pneumoniae ATCC 7000603, and Pseudomonas aeruginosa ATCC 278533. The well-diffusion test revealed significant antibacterial activity against all investigated bacteria when compared to vancomycin at a concentration of 1 mg/mL. The most susceptible bacteria to BaZnO, RuZnO, and CrZnO were Staphylococcus aureus (15.5 ± 0.5 mm), Pseudomonas aeruginosa (19.2 ± 0.5 mm), and Pseudomonas aeruginosa (19.7 ± 0.5), respectively. The MIC values indicated that they were in the range of 0.02 to 0.2 mg/mL. The MBC values showed that the tested bacteria's growth could be inhibited at concentrations ranging from 0.2 to 2.0 mg/mL. According to the MBC/MIC ratio, BaZnO, RuZnO, and CrZnO exhibit bacteriostatic effects and may target bacterial protein synthesis based on the results of the tolerance test. This study shows the efficacy of the above-mentioned nanoparticles on bacterial growth. Further biotechnological and toxicological studies on the nanoparticles fabricated here are recommended to benefit from these findings.
    Matched MeSH terms: Anti-Bacterial Agents/pharmacology; Bacteria
  10. Antibacterial Evaluation of Gallic Acid and its Derivatives against a Panel of Multi-drug Resistant Bacteria
    Abdella M, Lahiri C, Abdullah I, Anwar A
    Med Chem, 2024;20(2):130-139.
    PMID: 37612861 DOI: 10.2174/1573406419666230823104300
    BACKGROUND: Infectious diseases are the second leading cause of deaths worldwide. Pathogenic bacteria have been developing tremendous resistance against antibiotics which has placed an additional burden on healthcare systems. Gallic acid belongs to a naturally occurring phenolic class of compounds and is known to possess a wide spectrum of antimicrobial activities.

    AIMS & OBJECTIVES: In this study, we synthesized thirteen derivatives of gallic acid and evaluated their antibacterial potential against seven multi-drug resistant bacteria, as well as cytotoxic effects against human embryonic kidney cell line in vitro. Methods: 13 compounds were successfully synthesized with moderate to good yield and evaluated. Synthesized derivatives were characterized by using nuclear magnetic resonance spectroscopy, mass spectrometry, and Fourier transformation infrared spectroscopy. Antibacterial activity was determined using microdilution while cytotoxicyt was assessed using MTT assay.

    RESULTS: The results of antibacterial assay showed that seven out of thirteen compounds exhibited antibacterial effects with compound 6 and 13 being most potent against Staphylococcus aureus (MIC 56 μg/mL) and Salmonella enterica (MIC 475 μg/mL) respectively. On the other hand, most of these compounds showed lower cytotoxicity against human embryonic kidney cells (HEK 293), with IC50 values ranging from over 700 μg/mL.

    CONCLUSION: Notably, compound 13 was found to be non-toxic at concentrations as high as 5000 μg/mL. These findings suggest that the present synthetic derivatives of gallic acid hold potential for further studies in the development of potent antibacterial agents.

    Matched MeSH terms: Bacteria
  11. Chemical composition, antioxidant and antibacterial properties of the essential oils of Etlingera elatior and Cinnamomum pubescens Kochummen
    Abdelwahab SI, Zaman FQ, Mariod AA, Yaacob M, Abdelmageed AH, Khamis S
    J Sci Food Agric, 2010 Dec;90(15):2682-8.
    PMID: 20945508 DOI: 10.1002/jsfa.4140
    Plant essential oils are widely used as fragrances and flavours. Therefore, the essential oils from the leaves of Cinnamomum pubescens Kochummen (CP) and the whole plant of Etlingera elatior (EE) were investigated for their antioxidant, antibacterial and phytochemical properties.
    Matched MeSH terms: Anti-Bacterial Agents/isolation & purification; Anti-Bacterial Agents/pharmacology*; Anti-Bacterial Agents/chemistry; Bacteria/drug effects
  12. Coexisting mechanisms of bacterial community are changeable even under similar stable conditions in a chemostat culture
    Abdul Aziz FA, Suzuki K, Honjo M, Amano K, Mohd Din ARJB, Tashiro Y, et al.
    J Biosci Bioeng, 2021 Jan;131(1):77-83.
    PMID: 33268319 DOI: 10.1016/j.jbiosc.2020.09.009
    The coexisting mechanism of a synthetic bacterial community (SBC) was investigated to better understand how to manage microbial communities. The SBC was constructed with three kinds of phenol-utilizing bacteria, Pseudomonas sp. LAB-08, Comamonas testosteroni R2, and Cupriavidus sp. P-10, under chemostat conditions supplied with phenol as a sole carbon and energy source. Population densities of all strains were monitored by real-time quantitative PCR (qPCR) targeting the gene encoding the large subunit of phenol hydroxylase. Although the supply of phenol was stopped to allow perturbation in the SBC, all of the strains coexisted and the degradation of phenol was maintained for more than 800 days. The qPCR analyses showed that strains LAB-08 and R2 became dominant simultaneously, whereas strain P-10 was a minor population. This phenomenon was observed before and after the phenol-supply stoppage. The kinetic parameters for phenol of the SBC changed before and after the phenol-supply stoppage, which suggests a change in functional roles of strains in the SBC. Transcriptional levels of phenol hydroxylase and catechol dioxygenases of three strains were monitored by reverse-transcription qPCR (RT-qPCR). The RT-qPCR analyses revealed that all strains shared phenol and survived independently before the phenol-supply stoppage. After the stoppage, strain P-10 would incur the cost for degradation of phenol and catechol, whereas strains LAB-08 and R2 seemed to be cheaters using metabolites, indicating the development of the metabolic network. These results indicated that it is important for the management and redesign of microbial communities to understand the metabolism of bacterial communities.
    Matched MeSH terms: Bacteria/genetics; Bacteria/growth & development; Bacteria/metabolism*
  13. Fulltext Diet-induced metabolic changes of the human gut microbiome: importance of short-chain fatty acids, methylamines and indoles
    Abdul Rahim MBH, Chilloux J, Martinez-Gili L, Neves AL, Myridakis A, Gooderham N, et al.
    Acta Diabetol, 2019 May;56(5):493-500.
    PMID: 30903435 DOI: 10.1007/s00592-019-01312-x
    The human gut is a home for more than 100 trillion bacteria, far more than all other microbial populations resident on the body's surface. The human gut microbiome is considered as a microbial organ symbiotically operating within the host. It is a collection of different cell lineages that are capable of communicating with each other and the host and has an ability to undergo self-replication for its repair and maintenance. As the gut microbiota is involved in many host processes including growth and development, an imbalance in its ecological composition may lead to disease and dysfunction in the human. Gut microbial degradation of nutrients produces bioactive metabolites that bind target receptors, activating signalling cascades, and modulating host metabolism. This review covers current findings on the nutritional and pharmacological roles of selective gut microbial metabolites, short-chain fatty acids, methylamines and indoles, as well as discussing nutritional interventions to modulate the microbiome.
    Matched MeSH terms: Bacteria
  14. Pyrosequencing analysis of microbial community and food-borne bacteria on restaurant cutting boards collected in Seri Kembangan, Malaysia, and their correlation with grades of food premises
    Abdul-Mutalib NA, Amin Nordin S, Osman M, Ishida N, Tashiro K, Sakai K, et al.
    Int J Food Microbiol, 2015 May 4;200:57-65.
    PMID: 25679309 DOI: 10.1016/j.ijfoodmicro.2015.01.022
    This study adopts the pyrosequencing technique to identify bacteria present on 26 kitchen cutting boards collected from different grades of food premises around Seri Kembangan, a city in Malaysia. Pyrosequencing generated 452,401 of total reads of OTUs with an average of 1.4×10(7) bacterial cells/cm(2). Proteobacteria, Firmicutes and Bacteroides were identified as the most abundant phyla in the samples. Taxonomic richness was generally high with >1000 operational taxonomic units (OTUs) observed across all samples. The highest appearance frequencies (100%) were OTUs closely related to Enterobacter sp., Enterobacter aerogenes, Pseudomonas sp. and Pseudomonas putida. Several OTUs were identified most closely related to known food-borne pathogens, including Bacillus cereus, Cronobacter sakazaki, Cronobacter turisensis, Escherichia coli, E. coli O157:H7, Hafnia alvei, Kurthia gibsonii, Salmonella bongori, Salmonella enterica, Salmonella paratyphi, Salmonella tyhpi, Salmonella typhimurium and Yersinia enterocolitica ranging from 0.005% to 0.68% relative abundance. The condition and grade of the food premises on a three point cleanliness scale did not correlate with the bacterial abundance and type. Regardless of the status and grades, all food premises have the same likelihood to introduce food-borne bacteria from cutting boards to their foods and must always prioritize the correct food handling procedure in order to avoid unwanted outbreak of food-borne illnesses.
    Matched MeSH terms: Bacteria/classification; Bacteria/genetics*; Bacteria/isolation & purification*
  15. Characterization of aerobic granular sludge treating high strength agro-based wastewater at different volumetric loadings
    Abdullah N, Yuzir A, Curtis TP, Yahya A, Ujang Z
    Bioresour Technol, 2013 Jan;127:181-7.
    PMID: 23131639 DOI: 10.1016/j.biortech.2012.09.047
    Understanding the relationship between microbial community and mechanism of aerobic granulation could enable wider applications of granules for high-strength wastewater treatment. The majority of granulation studies principally determine the engineering aspects of granules formation with little emphasis on the microbial diversity. In this study, three identical reactors namely R1, R2 and R3 were operated using POME at volumetric loadings of 1.5, 2.5 and 3.5 kg COD m(-3) d(-1), respectively. Aeration was provided at a volumetric flow rate of 2.5 cms(-1). Aerobic granules were successfully developed in R2 and R3 while bioflocs dominated R1 until the end of experiments. Fractal dimension (D(f)) averaged at 1.90 suggesting good compactness of granules. The PCR-DGGE results indicated microbial evolutionary shift throughout granulation despite different operating OLRs based on decreased Raup and Crick similarity indices upon mature granule formation. The characteristics of aerobic granules treating high strength agro-based wastewater are determined at different volumetric loadings.
    Matched MeSH terms: Bacteria/genetics; Bacteria/metabolism*; Bacteria/ultrastructure
  16. Intraoral appliances for in situ oral biofilm growth: a systematic review
    Abdullah N, Al-Marzooq F, Mohamad S, Abd Rahman N, Chi Ngo H, Perera Samaranayake L
    J Oral Microbiol, 2019;11(1):1647757.
    PMID: 31489127 DOI: 10.1080/20002297.2019.1647757
    Background: Oral biofilms are the root cause of major oral diseases. As in vitro biofilms are not representative of the intraoral milieu, various devices have been manufactured over the years to develop Appliance Grown Oral Biofilm (AGOB). Objective: To review various intraoral appliances used to develop AGOB for microbiological analysis, and to judge the optimal means for such analyses. Design: Four databases (PubMed, Science Direct, Scopus and Medline) were searched by two independent reviewers, and articles featuring the key words 'device' OR 'splint' OR 'appliance'; 'Oral biofilm' OR 'dental plaque'; 'in vivo' OR 'in situ'; 'Microbiology' OR 'Bacteria' OR 'microbiome'; were included. The standard Reporting Items for Systematic Reviews and Meta-Analysis (PRISMA) were adopted for data gathering. Results: Of the 517 articles which met the initial inclusion criteria, 24 were deemed eligible for review. The age of the AGOB, sampled at various intervals, ranged from 30 min to 28 days. The most commonly used microbiome analytical methods were fluorescence microscopy, total cell count using conventional, and molecular tools including Next Generation Sequencing (NGS) platforms. Conclusions: No uniformly superior method for collecting AGOB could be discerned. NGS platforms are preferable for AGOB analyses.
    Matched MeSH terms: Bacteria
  17. Fulltext The antibacterial efficacy of silver diamine fluoride (SDF) is not modulated by potassium iodide (KI) supplements: A study on in-situ plaque biofilms using viability real-time PCR with propidium monoazide
    Abdullah N, Al Marzooq F, Mohamad S, Abd Rahman N, Rani KGA, Chi Ngo H, et al.
    PLoS One, 2020;15(11):e0241519.
    PMID: 33141868 DOI: 10.1371/journal.pone.0241519
    Silver diamine fluoride (SDF) is commonly used to arrest caries lesions, especially in early childhood caries. Recently, it was suggested that SDF can be combined with potassium iodide (KI) to minimize the discoloration of demineralized dentine associated with SDF application. However, the antibacterial efficacy of SDF alone or combined with KI on in-situ biofilm is unknown. Hence, we compared the anti-plaque biofilm efficacy of two different commercially available SDF solutions, with or without KI, using an in-situ biofilm, analysed using viability real-time PCR with propidium monoazide (PMA). Appliance-borne in-situ biofilm samples (n = 90) were grown for a period of 6 h in five healthy subjects who repeated the experiment on three separate occasions, using a validated, novel, intraoral device. The relative anti-biofilm efficacy of two SDF formulations; 38.0% Topamine (SDFT) and 31.3%, Riva Star (SDFR), KI alone, and KI in combination with SDFR (SDFR+KI) was compared. The experiments were performed by applying an optimized volume of the agents onto the biofilm for 1min, mimicking the standard clinical procedure. Afterwards the viability of the residual biofilm bacteria was quantified using viability real-time PCR with PMA, then the percentage of viable from total bacteria was calculated. Both SDF formulations (SDFT and SDFR) exhibited potent antibacterial activities against the in-situ biofilm; however, there was non-significant difference in their efficacy. KI alone did not demonstrate any antibacterial effect, and there was non-significant difference in the antibacterial efficacy of SDF alone compared to SDF with KI, (SDFT v SDFR/KI). Thus, we conclude that the antibacterial efficacy of SDF against plaque biofilms is not modulated by KI supplements. Viability real-time PCR with PMA was successfully used to analyze the viability of naturally grown oral biofilm; thus, the same method can be used to test the antimicrobial effect of other agents on oral biofilms in future research.
    Matched MeSH terms: Anti-Bacterial Agents; Bacteria
  18. The diversity of rhizospheric bacterial communities associated with Trichoderma-treated rice fields
    Abdullah NS, Doni F, Chua KO, Mispan MS, Saiman MZ, Mohd Yusuf Y, et al.
    Lett Appl Microbiol, 2022 Dec;75(6):1645-1650.
    PMID: 36073093 DOI: 10.1111/lam.13832
    Microbial-based fertilizer has been widely used as a healthier and better alternative to agrochemical products. However, the effects of biofertilizers on the rhizospheric microbiota has rarely been investigated. Thus, the aim of this study was to investigate the effects of symbiotic fungus Trichoderma asperellum SL2-based inoculant on the soil bacterial population through next generation sequencing using a metabarcoding approach. The treatment plots were treated with T. asperellum SL2 spore suspension, while the control plots were treated with sterilized distilled water. The results showed similar bacterial microbiome profiles in the soil of control and T. asperellum SL2-treated plots. In conclusion, the application of the T. asperellum SL2 inoculant had not exerted a negative impact towards the bacterial population as similar observation was reflected in control plots. Nonetheless, future research should be conducted to investigate the effects of repeated application of T. asperellum SL2 over a longer period on the rice microbiota communities.
    Matched MeSH terms: Bacteria/genetics
  19. Ganoderma boninense mycelia for phytochemicals and secondary metabolites with antibacterial activity
    Abdullah S, Jang SE, Kwak MK, Chong K
    J Microbiol, 2020 Dec;58(12):1054-1064.
    PMID: 33263896 DOI: 10.1007/s12275-020-0208-z
    Antiplasmodial nortriterpenes with 3,4-seco-27-norlanostane skeletons, almost entirely obtained from fruiting bodies, represent the main evidential source for bioactive secondary metabolites derived from a relatively unexplored phytopathogenic fungus, Ganoderma boninense. Currently lacking is convincing evidence for antimicrobial secondary metabolites in this pathogen, excluding that obtained from commonly observed phytochemicals in the plants. Herein, we aimed to demonstrate an efficient analytical approach for the production of antibacterial secondary metabolites using the mycelial extract of G. boninense. Three experimental cultures were prepared from fruiting bodies (GBFB), mycelium cultured on potato dextrose agar (PDA) media (GBMA), and liquid broth (GBMB). Through solvent extraction, culture type-dependent phytochemical distributions were diversely exhibited. Water-extracted GBMB produced the highest yield (31.21 ± 0.61%, p < 0.05), but both GBFB and GBMA elicited remarkably higher yields than GBMB when polar-organic solvent extraction was employed. Greater quantities of phytochemicals were also obtained from GBFB and GBMA, in sharp contrast to those gleaned from GBMB. However, the highest antibacterial activity was observed in chloroform-extracted GBMA against all tested bacteria. From liquid-liquid extractions (LLE), it was seen that mycelia extraction with combined chloroform-methanol-water at a ratio of 1:1:1 was superior at detecting antibacterial activities with the most significant quantities of antibacterial compounds. The data demonstrate a novel means of assessing antibacterial compounds with mycelia by LLE which avoids the shortcomings of standardized methodologies. Additionally, the antibacterial extract from the mycelia demonstrate that previously unknown bioactive secondary metabolites of the less studied subsets of Ganoderma may serve as active and potent antimicrobial compounds.
    Matched MeSH terms: Anti-Bacterial Agents/metabolism*; Anti-Bacterial Agents/pharmacology*; Anti-Bacterial Agents/chemistry; Bacteria/drug effects
  20. Fulltext Research progress in Bioflocculants from bacteria
    Abdullah, A.M., Hamidah, H., Alam, M.Z.
    International Food Research Journal, 2017;24(101):0-0.
    MyJurnal
    Although one of the major users of flocculants are water and wastewater treatment industries, flocculants are also used in various food industries. The chemical flocculants are preferred widely in these industries due to low production cost and fast production ability. However, the negative effects of the chemical flocculants should not be neglected to gain the economic benefits only. Therefore, the researchers are working to discover efficient and economical flocculants from biological sources. Several attempts have been made and are still being made to extract or produce bioflocculants from natural sources such as plants, bacteria, fungi, yeast, algae, etc. The review revealed that significant amount of work have been done in the past, in search of bioflocculant. However, commercially viable bioflocculants are yet to be marketed widely. With the advent of new biotechnologies and advances in genetic engineering, the researchers are hopeful to discover or develop commercially viable, safe and environmentfriendly bioflocculants.
    Matched MeSH terms: Bacteria
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