Displaying publications 141 - 160 of 942 in total

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  1. Fulltext Phytochemical and antimicrobial activity of Swietenia mahagoni crude methanolic seed extract
    Sahgal G, Ramanathan S, Sasidharan S, Mordi MN, Ismail S, Mansor SM
    Trop Biomed, 2009 Dec;26(3):274-9.
    PMID: 20237441 MyJurnal
    The present study was designed to evaluate the antibacterial activities of Swietenia mahagoni crude methanolic (SMCM) seed extract. The antimicrobial activity of the oily extract against Gram-positive, Gram-negative, yeast and fungus strains was evaluated based on the inhibition zone using disc diffusion assay, minimal inhibition concentration (MIC) and minimal bactericidal concentration (MBC) values. The crude extract was subjected to various phytochemicals analysis. The demonstrated qualitative phytochemical tests exhibited the presences of common phytocompounds including alkaloids, terpenoids, antraquinones, cardiac glycosides, saponins, and volatile oils as major active constituents. The SMCM seed extract had inhibitory effects on the growth of Candida albicans, Staphylococcus aureus, Pseudomonas aeroginosa, Streptococcus faecalis and Proteus mirabillase and illustrated MIC and MBC values ranging from 25 mg/ml to 50 mg/ml.
    Matched MeSH terms: Gram-Negative Bacteria/drug effects; Gram-Positive Bacteria/drug effects
  2. Microbial biodiversity in the throats of pulmonary tuberculosis patients and tuberculin skin test (TST) positive and negative healthy individuals in Malaysia
    Semail N, Suraiya S, Calero R, Mirabal M, Carrillo H, Ezzeddin Kamil MH, et al.
    Tuberculosis (Edinb), 2020 09;124:101965.
    PMID: 32692651 DOI: 10.1016/j.tube.2020.101965
    The purpose of this study was to investigate the composition of throat microbiota in pulmonary tuberculosis patients (PTB) in comparison to healthy tuberculin skin test positive (TSTp) and negative (TSTn) individuals. Throat swabs samples were collected, and the microbiota was characterized. Richer operational taxonomic units (OTUs) were present in PTB group, compared to TSTp and TSTn. Regarding alpha diversity analysis there was a higher community diversity in TSTn compared to TSTp. Beta diversity analysis showed different species composition in TSTp compared to TSTn and PTB. There was higher presence of Firmicutes in PTB and TSTn compared to TSTp group at phylum level. At the genus level, Leuconostoc and Enterococcus were higher in TSTn compared to TSTp and Pediococcus, Chryseobacterium, Bifidobacterium, Butyrivibrio, and Bulleidia were higher in PTB compared to TSTn. Streptococcus was higher in TSTn compared to PTB and Lactobacillus in PTB compared to TSTp. At species level, Streptococcus sobrinus and Bulleidia moorei were higher in PTB compared to TSTn individuals, while Lactobacillus salivarius was higher in PTB compared to TSTp. The differences in the microbiome composition could influence the resistance/susceptibility to Mtb infection.
    Matched MeSH terms: Bacteria/classification; Bacteria/genetics; Bacteria/isolation & purification*
  3. A review on the potential of polyhydroxyalkanoates production from oil-based substrates
    Chien Bong CP, Alam MNHZ, Samsudin SA, Jamaluddin J, Adrus N, Mohd Yusof AH, et al.
    J Environ Manage, 2021 Nov 15;298:113461.
    PMID: 34435568 DOI: 10.1016/j.jenvman.2021.113461
    Polyhydroxyalkanoate (PHA) is a type of polyesters produced in the form of accumulated intracellular granules by many microorganisms. It is viewed as an environmentally friendly bioproduct due to its biodegradability and biocompatibility. The production of the PHA using oil substrates such as waste oil and plant oil, has gained considerable attention due to the high product yield and lower substrate cost. Nevertheless, the PHA fermentation using oil substrate is complicated due to the heterogenous fatty acid composition, varied bio-accessibility and possible inhibitory effect on the bacterial culture. This review presents the current state-of-the-art of PHA production from oil-based substrates. This paper firstly discusses the technical details, such as the choice of bacteria strain and fermentation conditions, characteristic of the oil substrate as well as the PHA composition and application. Finally, the paper discusses the challenges and prospects for up-scaling towards a cleaner and effective bioprocess. From the literature review, depending on the cell culture and the type of PHA produced, the oil platform can have a PHA yield of 0.2-0.8 g PHA/g oil substrate, with PHA content mostly from 40 to 90% of the cell dry weight. There is an on-going search for more effective oil-utilising PHA producers and lower cost substrate for effective PHA production. The final application of the PHA polymer influences the treatment needed during downstream processing and its economic performance. PHA with different compositions exhibits varied decomposition behaviour under different conditions, requiring further insight towards its management towards a sustainable circular economy.
    Matched MeSH terms: Bacteria
  4. Fulltext Effectiveness of domestic water filters in removing suspended solids, residual chlorine and coliform bacteria
    Chong, Chee Kheong, Vijayakumar, G., Teoh, Leong Hooi, Siti Zubaidah, A.R., Mohamed Sapian, M., Abdul Rahim, A.
    Malaysian Journal of Public Health Medicine, 2003;3(2):38-40.
    MyJurnal
    Water filters are being increasingly promoted and used in the home. There are many types of commercial water jilters available for domestic use but almost all of them employ a physical filter media and an activated substance. The study showed that water filters effectively removed suspended solids and residual chlorine. However, as far as removing colhform bacteria is concerned, in ZZ .5% of the cases, bacteria were in fact introduced into the water. And in 20% ofthe cases, the amount of bacteria introduced was “too numerous to count (TNTC)". Furthermore, water hlters can lose their ability to filter bacteria without losing their ability to filter suspended solids and residual chlorine. This highlights the necessity of some authorized body looking into the claims made by these water filter manufacturers and impose certain standards to ensure that at the very least, the water quality ofthe hltered water is not worse than the unfiltered water.
    Matched MeSH terms: Bacteria
  5. Fulltext An overview of bacterial concrete on concrete durability in aggressive environment
    Irwan, J.M., Teddy, T.
    Pertanika Journal of Science & Technology, 2017;25(105):259-264.
    MyJurnal
    Concrete durability determines service life of structures. It can though, be weakened by aggressive environmental conditions. For instance, bio-corrosion process is due to the presence and activity of microorganisms which produce sulphuric acid to form sulphate deterioration of concrete materials. The problems related to durability and repair systems are due to lack of suitable concrete materials. The use bacteria for concrete repairing and plugging of pores and cracking in concrete has been recently explored. Previous studies had proved the possibility of using specific bacteria via bio concrete as a sustainable method for improving concrete properties. Thus, lack of information on the application of bio concrete exposed to extreme condition was the motivation for this research.
    Matched MeSH terms: Bacteria
  6. Fulltext Gelatin-polysaccharide based materials: A review of processing and properties
    Asiyanbi, T.T., Bio-Sawe, W., Idris, M.A., Hammed, A.M.
    International Food Research Journal, 2017;24(101):0-0.
    MyJurnal
    The advent of green technology has flourished biomolecule applications in medical, pharmaceutical and food products. Unlike synthetic materials, gelatin-polysaccharide matrixes are generally recognized as safe (GRAS). Gelatin-polysaccharide complexes are currently being utilized for the development of nano- and micro-particles, hydrogel, aerogel and films. Gelatin-polysaccharide based materials have offered improved characteristics depending on the type and concentration of polysaccharide and crosslinking agent. Gelatin-polysaccharide based materials function as bioactive compounds entrapment and encapsulation and anti-bacteria. This review provides concise information on the theory and technological applications of gelatin-polysaccharides based materials.
    Matched MeSH terms: Bacteria
  7. Novel multifunctional plant growth-promoting bacteria in co-compost of palm oil industry waste
    Chin CFS, Furuya Y, Zainudin MHM, Ramli N, Hassan MA, Tashiro Y, et al.
    J Biosci Bioeng, 2017 Nov;124(5):506-513.
    PMID: 28736147 DOI: 10.1016/j.jbiosc.2017.05.016
    Previously, a unique co-compost produced by composting empty fruit bunch with anaerobic sludge from palm oil mill effluent, which contributed to establishing a zero-emission industry in Malaysia. Little was known about the bacterial functions during the composting process and fertilization capacity of this co-compost. We isolated 100 strains from the co-compost on 7 types of enumeration media and screened 25 strains using in vitro tests for 12 traits, grouping them according to three functions: plant growth promoting (fixation of nitrogen; solubilization of phosphorus, potassium, and silicate; production of 3-indoleacetic acid, ammonia, and siderophore), biocontrolling (production of chitinase and anti-Ganoderma activity), and composting (degradation of lignin, xylan, and cellulose). Using 16S rRNA gene sequence analysis, 25 strains with strong or multi-functional traits were found belong to the genera Bacillus, Paenibacillus, Citrobacter, Enterobacter, and Kosakonia. Furthermore, several strains of Citrobacter sedlakii exhibited a plant growth-stimulation in vivo komatsuna plant cultivation test. In addition, we isolated several multifunctional strains; Bacillus tequilensis CE4 (biocontrolling and composting), Enterobacter cloacae subsp. dissolvens B3 (plant growth promoting and biocontrolling), and C. sedlakii CESi7 (plant growth promoting and composting). Some bacteria in the co-compost play significant roles during the composting process and plant cultivation after fertilization, and some multifunctional strains have potential for use in accelerating the biodegradation of lignocellulosic biomass, protecting against Ganoderma boninense infection, and increasing the yield of palm oil.
    Matched MeSH terms: Bacteria/genetics; Bacteria/isolation & purification; Bacteria/metabolism*
  8. 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
  9. In vitro characteristics of an Atlantic salmon (Salmo salar L.) hind gut microbial community in relation to different dietary treatments
    Zarkasi KZ, Taylor RS, Glencross BD, Abell GCJ, Tamplin ML, Bowman JP
    Res. Microbiol., 2017 Oct;168(8):751-759.
    PMID: 28728852 DOI: 10.1016/j.resmic.2017.07.003
    In this study, microbial community dynamics were assessed within a simple in vitro model system in order to understand those changes influenced by diet. The abundance and diversity of bacteria were monitored within different treatment slurries inoculated with salmon faecal samples in order to mimic the effects of dietary variables. A total of five complete diets and two ingredients (plant meal) were tested. The total viable counts (TVCs) and sequencing data revealed that there was very clear separation between the complete diets and the plant meal treatments, suggesting a dynamic response by the allochthonous bacteria to the treatments. Automated ribosomal intergenic spacer analysis (ARISA) results showed that different diet formulations produced different patterns of fragments, with no separation between the complete diets. However, plant-based protein ingredients were clearly separated from the other treatments. 16S rRNA Illumina-based sequencing analysis showed that members of the genera Aliivibrio, Vibrio and Photobacterium became predominant for all complete diets treatments. The plant-based protein ingredient treatments only sustained weak growth of the genus Sphingomonas. In vitro based testing of diets could be a useful strategy to determine the potential impact of either complete feeds or ingredients on major fish gastrointestinal tract microbiome members.
    Matched MeSH terms: Bacteria/classification; Bacteria/genetics; Bacteria/isolation & purification*
  10. First report of foregut microbial community in proboscis monkeys: are diverse forests a reservoir for diverse microbiomes?
    Hayakawa T, Nathan SKSS, Stark DJ, Saldivar DAR, Sipangkui R, Goossens B, et al.
    Environ Microbiol Rep, 2018 12;10(6):655-662.
    PMID: 29992728 DOI: 10.1111/1758-2229.12677
    Foregut fermentation is well known to occur in a wide range of mammalian species and in a single bird species. Yet, the foregut microbial community of free-ranging, foregut-fermenting monkeys, that is, colobines, has not been investigated so far. We analysed the foregut microbiomes in four free-ranging proboscis monkeys (Nasalis larvatus) from two different tropical habitats with varying plant diversity (mangrove and riverine forests), in an individual from a semi-free-ranging setting with supplemental feeding, and in an individual from captivity, using high-throughput sequencing based on 16S ribosomal RNA genes. We found a decrease in foregut microbial diversity from a diverse natural habitat (riverine forest) to a low diverse natural habitat (mangrove forest), to human-related environments. Of a total of 2700 bacterial operational taxonomic units (OTUs) detected in all environments, only 153 OTUs were shared across all individuals, suggesting that they were not influenced by diet or habitat. These OTUs were dominated by Firmicutes and Proteobacteria. The relative abundance of the habitat-specific microbial communities showed a wide range of differences among living environments, although such bacterial communities appeared to be dominated by Firmicutes and Bacteroidetes, suggesting that those phyla are key to understanding the adaptive strategy in proboscis monkeys living in different habitats.
    Matched MeSH terms: Bacteria/classification; Bacteria/genetics; Bacteria/isolation & purification
  11. El Niño Altered Gut Microbiota of Children: A New Insight on Weather-Gut Interactions and Protective Effects of Probiotic
    Lau ASY, Mitsuyama E, Odamaki T, Xiao JZ, Liong MT
    J Med Food, 2019 Mar;22(3):230-240.
    PMID: 30183458 DOI: 10.1089/jmf.2018.4276
    Changes in weather often trigger a myriad of negative impacts on the environment, which eventually affect human health. During the early months of 2016, Malaysia experienced El Niño, with an extremely dry season of almost zero rainfall. At the same time, an increase of more than twofold in fecal secretary immunoglobulin-A (SIgA) levels of healthy preschool children aged 2-6 years was observed, accompanied by an increase in phylum Bacteroidetes, predominantly attributed to genus Bacteroides and Odoribacter, which also positively correlated with fecal SIgA levels. Here, we present evidence to illustrate the detrimental effects of weather change on a microscopic "environment," the human gut ecosystem. We also discuss the protective effects of probiotic against dysbiosis as induced by weather change. The increase in Bacteroidetes was at an expense of decreased genus Faecalibacterium and Veillonella (phylum Firmicutes), whereas children consuming probiotic had a decrease in genus Collinsella, Atopobium, and Eggerthella (phylum Actinobacteria) instead.
    Matched MeSH terms: Bacteria/classification; Bacteria/genetics; Bacteria/isolation & purification
  12. Studies on the viability of typhoid bacilli in local syrups
    Iyer KG
    Med J Malaya, 1950;5.
    The viability of three recently isolated local strains of Bact. typhosus has been studied on 20 specimens of local hawker’s syrup used for sweetening ice balls and ice water. Precise survival times cannot be stated and only relatively wide limits can be estimated differing possibly in every individual case. Survival is influenced by the following factors : 1. The character of the containing material 2. The presence of other bacteria 3. Temperature 4. The presence of bactericidal agents or substances Significant diminution of the number of bacteria in 2 to 5 days after inoculation to sugar solutions is an important observation although survival up to two weeks has been noticed in repeated experiments. The results of experiments conducted in market syrup samples and on control experiments with laboratory sugar solutions indicate that the survival of the organisms tends to be more prolonged in dilute solutions than in concentrated
    Matched MeSH terms: Bacteria
  13. Fulltext Identification, Growth Profile and Probiotic Properties of Autochthonous Intestinal Bacteria of Sagor catfish (Hexanematichthys sagor)
    Pang Sing T, Julian R, Hatai K
    Biocontrol Sci, 2019;24(1):1-11.
    PMID: 30880308 DOI: 10.4265/bio.24.1
    　The prevalence of antibiotic resistant bacteria in aquaculture has reached alarming proportions and intensified the search for microbe derived antimicrobial compounds. This study isolated bacteria from the intestine of Sagor catfish (Hexanematichthys sagor) and screened it for antagonistic properties. Five out of 334 bacterial isolates inhibited growth of fish pathogens. The 5 bacterial strains included relatives of Shewanella haliotis, Myroides odoratimimus, Vibrio harveyi, Vibrio alginolyticus and Alcaligenes faecalis. The growth profiles and probiotic properties of these bacteria were examined. The results showed that the isolate 9 (3) 7.5.2.1, whose closest relative was S. haliotis exhibited growth and probiotic advantage compared to the other bacterial strains, such as highest doubling time and the ability to survive at all experimental temperatures (18 to 60℃) , and bile concentrations (0.01 to 1.00%) and pH (pH2 to 9) . While the bacteria with probiotic properties were successfully isolated. Further study is necessary to examine the efficiency of the probiotic candidate bacteria in boosting fish immunity against pathogens.
    Matched MeSH terms: Bacteria/classification; Bacteria/growth & development*; Bacteria/isolation & purification
  14. Effects of aqueous plant extracts on the phagocytic capability and intracellular killing of Staphyococcus aureus by murine peritoneal macrophages in vitro
    Mahmood AA, Khiarul Anwar A, Ansary A, Sidik K, Salmah I, Suzainur KAR
    JUMMEC, 2001;6:30-33.
    Nine local plant species were picked randomly and their aqueous extracts have been screened to know their effects on the phagocytic capability and intracellular killing of StapllylococclIs al/rellS bacteria by mouse peritoneal macrophages. Macrophage cultures were incubated with different concentration of each plant extracts forI hour. Among these aqueous extracts, Ageratum conyzoides and Malastoma melabathricum inhibited the phagocytic capability and intracellular killing of Stapllylococclls aureus compared with controls. Elicited (activated) cells have more phagocytic capability and intracellular killing than the resident (normal) macrophages. There were no differences in the viability of cells between treated cells (with extracts) and controls (without extracts). KEYWORDS: Aqueous plant extracts, murine macrophage, phagocytosis.
    Matched MeSH terms: Bacteria
  15. Antimicrobial properties of starch films incorporated with chitosan nanoparticles: In vitro and in vivo evaluation
    Shapi'i RA, Othman SH, Nordin N, Kadir Basha R, Nazli Naim M
    Carbohydr Polym, 2020 Feb 15;230:115602.
    PMID: 31887886 DOI: 10.1016/j.carbpol.2019.115602
    Chitosan nanoparticles (CNP) were synthesized via ionic gelation and used for the preparation of starch-based nanocomposite films containing different concentration of CNP (0, 5, 10, 15, 20% w/w). Antimicrobial properties of starch/CNP films was evaluated via in vitro (disc diffusion analysis) and in vivo (microbial count in wrapped cherry tomatoes) study. It was found that inhibitory zone of the 15 and 20% of starch/CNP films were clearly observed for all the tested bacteria including Bacillus cereus, Staphylococcus aureus, Escherichia coli and Salmonella typhimurium. In vivo study revealed that the starch/CNP film (15% w/w) was more efficient to inhibit the microbial growth in cherry tomatoes (7 × 102 CFU/g) compared to neat starch film (2.15 × 103 CFU/g) thus confirmed the potential application of the films as antimicrobial food packaging.
    Matched MeSH terms: Gram-Negative Bacteria/drug effects; Gram-Positive Bacteria/drug effects
  16. Genome-scale metabolic models as platforms for identification of novel genes as antimicrobial drug targets
    Mienda BS, Salihu R, Adamu A, Idris S
    Future Microbiol, 2018 03;13:455-467.
    PMID: 29469596 DOI: 10.2217/fmb-2017-0195
    The growing number of multidrug-resistant pathogenic bacteria is becoming a world leading challenge for the scientific community and for public health. However, advances in high-throughput technologies and whole-genome sequencing of bacterial pathogens make the construction of bacterial genome-scale metabolic models (GEMs) increasingly realistic. The use of GEMs as an alternative platforms will expedite identification of novel unconditionally essential genes and enzymes of target organisms with existing and forthcoming GEMs. This approach will follow the existing protocol for construction of high-quality GEMs, which could ultimately reduce the time, cost and labor-intensive processes involved in identification of novel antimicrobial drug targets in drug discovery pipelines. We discuss the current impact of existing GEMs of selected multidrug-resistant pathogenic bacteria for identification of novel antimicrobial drug targets and the challenges of closing the gap between genome-scale metabolic modeling and conventional experimental trial-and-error approaches in drug discovery pipelines.
    Matched MeSH terms: Anti-Bacterial Agents*; Bacteria/drug effects; Bacteria/genetics*; Bacteria/metabolism; Genes, Bacterial; Genome, Bacterial/genetics*
  17. Fulltext Acinetobacter spp. infections in Malaysia: a review of antimicrobial resistance trends, mechanisms and epidemiology
    Mohd Rani F, A Rahman NI, Ismail S, Alattraqchi AG, Cleary DW, Clarke SC, et al.
    Front Microbiol, 2017;8:2479.
    PMID: 29312188 DOI: 10.3389/fmicb.2017.02479
    Acinetobacter spp. are important nosocomial pathogens, in particular the Acinetobacter baumannii-calcoaceticus complex, which have become a global public health threat due to increasing resistance to carbapenems and almost all other antimicrobial compounds. High rates of resistance have been reported among countries in Southeast Asia, including Malaysia. In this review, we examine the antimicrobial resistance profiles of Acinetobacter spp. hospital isolates from Malaysia over a period of nearly three decades (1987-2016) with data obtained from various peer-reviewed publications as well as the Malaysian National Surveillance on Antibiotic Resistance (NSAR). NSAR data indicated that for most antimicrobial compounds, including carbapenems, the peak resistance rates were reached around 2008-2009 and thereafter, rates have remained fairly constant (e.g., 50-60% for carbapenems). Individual reports from various hospitals in Peninsular Malaysia do not always reflect the nationwide resistance rates and often showed higher rates of resistance. We also reviewed the epidemiology and mechanisms of resistance that have been investigated in Malaysian Acinetobacter spp. isolates, particularly carbapenem resistance and found that blaOXA-23 is the most prevalent acquired carbapenemase-encoding gene. From the very few published reports and whole genome sequences that are available, most of the Acinetobacter spp. isolates from Malaysia belonged to the Global Clone 2 (GC2) CC92 group with ST195 being the predominant sequence type. The quality of data and analysis in the national surveillance reports could be improved and more molecular epidemiology and genomics studies need to be carried out for further in-depth understanding of Malaysian Acinetobacter spp. isolates.
    Matched MeSH terms: Bacteria; Drug Resistance, Bacterial*
  18. Distribution of faecal indicator bacteria in tropical waters of Peninsular Malaysia and their decay rates in tropical seawater
    Wong YY, Lee CW, Chai SCY, Lim JH, Bong CW, Sim EUH, et al.
    Mar Pollut Bull, 2022 Dec;185(Pt A):114297.
    PMID: 36327936 DOI: 10.1016/j.marpolbul.2022.114297
    We investigated the appropriateness of faecal indicator bacteria in tropical waters. We compared total coliform (undetectable to 7.2 × 105 cfu 100 mL-1), faecal coliform (undetectable to 6.1 × 105 cfu 100 mL-1) and enterococci (undetectable to 3.1 × 104 cfu 100 mL-1) distribution in Peninsular Malaysia. Faecal indicator bacteria was highest in freshwater, and lowest in seawater (q > 4.18, p bacteria in tropical waters was not due to faecal pollution alone, and this will have serious implications towards the use of these faecal indicator bacteria.
    Matched MeSH terms: Bacteria
  19. Fulltext Characterization of bacterial communities associated with blood-fed and starved tropical bed bugs, Cimex hemipterus (F.) (Hemiptera): a high throughput metabarcoding analysis
    Lim L, Ab Majid AH
    Sci Rep, 2021 Apr 19;11(1):8465.
    PMID: 33875727 DOI: 10.1038/s41598-021-87946-w
    With the development of new metagenomic techniques, the microbial community structure of common bed bugs, Cimex lectularius, is well-studied, while information regarding the constituents of the bacterial communities associated with tropical bed bugs, Cimex hemipterus, is lacking. In this study, the bacteria communities in the blood-fed and starved tropical bed bugs were analysed and characterized by amplifying the v3-v4 hypervariable region of the 16S rRNA gene region, followed by MiSeq Illumina sequencing. Across all samples, Proteobacteria made up more than 99% of the microbial community. An alpha-proteobacterium Wolbachia and gamma-proteobacterium, including Dickeya chrysanthemi and Pseudomonas, were the dominant OTUs at the genus level. Although the dominant OTUs of bacterial communities of blood-fed and starved bed bugs were the same, bacterial genera present in lower numbers were varied. The bacteria load in starved bed bugs was also higher than blood-fed bed bugs.
    Matched MeSH terms: Bacteria/classification*; Bacteria/genetics; Bacteria/isolation & purification*
  20. Nanovesicle and extracellular polymeric substance synthesis from the remediation of heavy metal ions from soil
    Budamagunta V, Shameem N, Irusappan S, Parray JA, Thomas M, Marimuthu S, et al.
    Environ Res, 2023 Feb 15;219:114997.
    PMID: 36529326 DOI: 10.1016/j.envres.2022.114997
    Heavy metal toxicity affects aquatic plants and animals, disturbing biodiversity and ecological balance causing bioaccumulation of heavy metals. Industrialization and urbanization are inevitable in modern-day life, and control and detoxification methods need to be accorded to meet the hazardous environment. Microorganisms and plants have been widely used in the bioremediation of heavy metals. Sporosarcina pasteurii, a gram-positive bacterium that is widely known for its calcite precipitation property in bio-cementing applications has been explored in the study for its metal tolerance ability for the first time. S. pasteurii SRMNP1 (KF214757) can tolerate silver stress to form nanoparticles and can remediate multiple heavy metals to promote the growth of various plants. This astounding property of the isolate warranted extensive examinations to comprehend the physiological changes during an external heavy metal stress condition. The present study aimed to understand various physiological responses occurring in S. pasteuriiSRMNP1 during the metal tolerance phenomenon using electron microscopy. The isolate was subjected to heavy metal stress, and a transmission electron microscope examination was used to analyze the physiological changes in bacteria to evade the metal stress. S. pasteurii SRMNP1 was tolerant against a wide range of heavy metal ions and can withstand a broad pH range (5-9). Transmission Electron Microscopy (TEM) examination of S. pasteurii SRMNP1 followed by 5 mM nickel sulfate treatment revealed the presence of nanovesicles encapsulating nanosized particles in intra and extracellular spaces. This suggests that the bacteria evade the metal stress by converting the metal ions into nanosized particles and encapsulating them within nanovesicles to efflux them through the vesicle budding mechanism. Moreover, the TEM images revealed an excessive secretion of extracellular polymeric substances by the strain to discharge the metal particles outside the bacterial system. S. pasteurii can be foreseen as an effective bioremediation agent with the potential to produce nanosized particles, nanovesicles, and extracellular polymeric substances. This study provides physiological evidence that, besides calcium precipitation applications, S. pasteurii can further be explored for its multidimensional roles in the fields of drug delivery and environmental engineering.
    Matched MeSH terms: Bacteria
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