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Fulltext Multidrug-resistant bacteria and microbial communities in a river estuary with fragmented suburban waste management

Ho JY, Jong MC, Acharya K, Liew SSX, Smith DR, Noor ZZ, et al.

J Hazard Mater, 2021 03 05;405:124687.
PMID: 33301976 DOI: 10.1016/j.jhazmat.2020.124687

River systems in developing and emerging countries are often fragmented relative to land and waste management in their catchment. The impact of inconsistent waste management and releases is a major challenge in water quality management. To examine how anthropogenic activities and estuarine effects impact water quality, we characterised water conditions, in-situ microbiomes, profiles of faecal pollution indicator, pathogenic and antibiotic resistant bacteria in the River Melayu, Southern Malaysia. Overall, upstream sampling locations were distinguished from those closer to the coastline by physicochemical parameters and bacterial communities. The abundances of bacterial DNA, total E. coli marker genes, culturable bacteria as well as antibiotic resistance ESBL-producing bacteria were elevated at upstream sampling locations especially near discharge of a wastewater oxidation pond. Furthermore, 85.7% of E. faecalis was multidrug-resistant (MDR), whereas 100% of E. cloacae, E. coli, K. pneumoniae were MDR. Overall, this work demonstrates how pollution in river estuaries does not monotonically change from inland towards the coast but varies according to local waste releases and tidal mixing. We also show that surrogate markers, such dissolved oxygen, Bacteroides and Prevotella abundances, and the rodA qPCR assay for total E. coli, can identify locations on a river that deserve immediate attention to mitigate AMR spread through improved waste management.

Matched MeSH terms: Anti-Bacterial Agents/analysis; Anti-Bacterial Agents/pharmacology; Bacteria/genetics
Microbiota composition of captive bluestreak cleaner wrasse Labroides dimidiatus (Valenciennes, 1839)

Nurul AAN, Danish-Daniel AM, Okomoda VT, Asma NA

Appl Microbiol Biotechnol, 2020 Sep;104(17):7391-7407.
PMID: 32676710 DOI: 10.1007/s00253-020-10781-y

The Labroides dimidiatus is one of the most traded marine ornamental fishes worldwide, yet not much is known about the microflora associated with this fish. This study is designed to investigate the bacteria composition associated with captive L. dimidiatus and its surrounding aquarium water. The fish and carriage water were obtained from well-known ornamental fish suppliers in Terengganu Malaysia. Bacteria present on the skin and in the stomach and the aquarium water were enumerated using culture-independent approaches and next-generation sequencing (NGS) technology. A total of 3,238,564 valid reads and 828 total operational taxonomic units (OTUs) were obtained from the three metagenomic libraries using NGS analysis. Of all the 15 phyla identified in this study, Proteobacteria, Bacteroidetes, Firmicutes, and Actinobacteria were the most prevalent in all samples. Also, 170 families belonging to 36 bacteria classes were identified. Although many of the bacteria families were common in the skin, gut, and aquarium water (39%), about 26% of the families were exclusive to the aquarium water alone. Therefore, any substantial change in the structure and abundance of microbiota (especially pathogenic bacteria) reported in this study may serve as an early sign for disease infection in the species under captivity. KEY POINTS: • Proteobacteria was the most dominant. • The microbiota was either shared or exclusively in samples.

Matched MeSH terms: Bacteria/genetics
Fulltext Microbial Enzymes and Their Applications in Industries and Medicine 2016

Anbu P, Gopinath SCB, Chaulagain BP, Lakshmipriya T

Biomed Res Int, 2017 03 28;2017:2195808.
PMID: 28459056 DOI: 10.1155/2017/2195808
Matched MeSH terms: Bacteria/enzymology*; Bacterial Proteins/therapeutic use*; Bacterial Proteins/chemistry*
Fulltext Microbial Decolorization of Triazo Dye, Direct Blue 71: An Optimization Approach Using Response Surface Methodology (RSM) and Artificial Neural Network (ANN)

Zin KM, Effendi Halmi MI, Abd Gani SS, Zaidan UH, Samsuri AW, Abd Shukor MY

Biomed Res Int, 2020;2020:2734135.
PMID: 32149095 DOI: 10.1155/2020/2734135

The release of wastewater from textile dyeing industrial sectors is a huge concern with regard to pollution as the treatment of these waters is truly a challenging process. Hence, this study investigates the triazo bond Direct Blue 71 (DB71) dye decolorization and degradation dye by a mixed bacterial culture in the deficiency source of carbon and nitrogen. The metagenomics analysis found that the microbial community consists of a major bacterial group of Acinetobacter (30%), Comamonas (11%), Aeromonadaceae (10%), Pseudomonas (10%), Flavobacterium (8%), Porphyromonadaceae (6%), and Enterobacteriaceae (4%). The richest phylum includes Proteobacteria (78.61%), followed by Bacteroidetes (14.48%) and Firmicutes (3.08%). The decolorization process optimization was effectively done by using response surface methodology (RSM) and artificial neural network (ANN). The experimental variables of dye concentration, yeast extract, and pH show a significant effect on DB71 dye decolorization percentage. Over a comparative scale, the ANN model has higher prediction and accuracy in the fitness compared to the RSM model proven by approximated R2 and AAD values. The results acquired signify an efficient decolorization of DB71 dye by a mixed bacterial culture.

Matched MeSH terms: Bacteria/classification
An Overview on the Toxicological Properties of Ionic Liquids toward Microorganisms

Sivapragasam M, Moniruzzaman M, Goto M

Biotechnol J, 2020 Apr;15(4):e1900073.
PMID: 31864234 DOI: 10.1002/biot.201900073

Ionic liquids (ILs), a class of materials with unique physicochemical properties, have been used extensively in the fields of chemical engineering, biotechnology, material sciences, pharmaceutics, and many others. Because ILs are very polar by nature, they can migrate into the environment with the possibility of inclusion in the food chain and bioaccumulation in living organisms. However, the chemical natures of ILs are not quintessentially biocompatible. Therefore, the practical uses of ILs must be preceded by suitable toxicological assessments. Among different methods, the use of microorganisms to evaluate IL toxicity provides many advantages including short generation time, rapid growth, and environmental and industrial relevance. This article reviews the recent research progress on the toxicological properties of ILs toward microorganisms and highlights the computational prediction of various toxicity models.

Matched MeSH terms: Bacteria/drug effects
Tropical ulcers: the first imported cases and review of the literature

Veraldi S, Faraci AG, Valentini D, Bottini S

Eur J Dermatol, 2021 Feb 01;31(1):75-80.
PMID: 33648916 DOI: 10.1684/ejd.2021.3968

BACKGROUND: A tropical ulcer is a bacterial necrotizing disease of the skin, with an acute or chronic clinical course, caused by anaerobic bacteria, notably Fusobacteria spp.
OBJECTIVES: We present six Italian tourists who acquired tropical ulcers in tropical and subtropical countries.
MATERIALS & METHODS: Four males and two females acquired a skin ulcer during trips to Brazil, Malaysia, Fiji Islands, Zambia, Tanzania and India. In all patients, medical history, physical and dermatological examination, laboratory tests, bacteriological examinations and biopsy were carried out.
RESULTS: All patients were in good general health. All patients stated that the ulcer was caused by a trauma. No fever was reported. Neither lymphangitis nor lymphadenopathy were detected. The ulcer was located on a forearm in one patient, on a leg in two and on an ankle in three patients. All ulcers were malodorous and painful. Laboratory tests revealed mild leucocytosis and a mild increase in erythrocyte sedimentation rate and C-reactive protein. Results of bacteriological examinations revealed the presence of Fusobacterium spp. in five patients. Other bacteria were identified in all patients. Histopathological examination showed: necrosis of the epidermis and dermis; vascular dilatation; oedema in the dermis; massive infiltration with neutrophils, lymphocytes and histiocytes; and fragmented collagen bundles. No signs of vasculitis were observed. All patients were successfully treated with oral metronidazole (1 g/day for two weeks) and, according to antibiograms, with different systemic antibiotics.
CONCLUSION: To our knowledge, these are the first cases of tropical ulcers reported in Western tourists.

Matched MeSH terms: Bacteria, Anaerobic*
Bacteria flora and heavy metals in cultivated oysters Crassostrea iredalei of Setiu Wetland, East Coast Peninsular Malaysia

Najiah M, Nadirah M, Lee KL, Lee SW, Wendy W, Ruhil HH, et al.

Vet Res Commun, 2008 Jun;32(5):377-81.
PMID: 18369732 DOI: 10.1007/s11259-008-9045-y

Slipper oyster Crassostrea iredalei is a species of good demand for its sweet flavor and white coloured flesh. The filter feeding nature predisposes oysters to accumulation of pathogenic and heavy metals in waters impacted by sewage pollutions and may thus render the oysters unfit for human consumption. A study was undertaken to investigate the presence of bacteria flora and heavy metal concentrations in cultivated oysters Crassostrea iredalei at Setiu Wetland, Terengganu, the only source of cultivated oysters in East Coast of Malaysia. A total of 200 slipper oyster samples were analyzed. The bacteria were isolated using non selective agar such as TSA agar and selective agars before they were then identified using conventional methods in combination with BBL Crystal identification kit. Heavy metals such as zinc (Zn), copper (Cu), cadmium (Cd), and lead (Pb) concentrations were determined using atomic absorption spectrophotometry. Results showed that the oysters harbor predominantly Shewanella putrifaciens followed by Vibrio parahaemolyticus, Vibrio vulnificus, Vibrio cholerae, Enterobacter cloacae, Escherichia coli and Chromobacterium violaceum. They also contain high concentration of Zn (785.68 +/- 285.88 microg/g) with the lowest heavy metal was Pb (0.17 +/- 0.15 microg/g), whilst the concentrations of other heavy metals were Cu (38.9 +/- 13.2 microg/g) and Cd (1.60 +/- 0.28 microg/g). The study is very useful to evaluate the type of bacteria and heavy metal present in oyster meat for human consumption.

Matched MeSH terms: Bacteria/isolation & purification*
Compositional profile of mucosal bacteriome of smokers and smokeless tobacco users

Gopinath D, Wie CC, Banerjee M, Thangavelu L, Kumar R P, Nallaswamy D, et al.

Clin Oral Investig, 2022 Feb;26(2):1647-1656.
PMID: 34436669 DOI: 10.1007/s00784-021-04137-7

INTRODUCTION: Smoked, and especially smokeless, tobacco are major causes of oral cancer globally. Here, we examine the oral bacteriome of smokers and of smokeless tobacco users, in comparison to healthy controls, using 16S rRNA gene sequencing.
METHODS: Oral swab samples were collected from smokers, smokeless tobacco users, and healthy controls (n = 44). Microbial DNA was extracted and the 16S rRNA gene profiled using the Illumina MiSeq platform. Sequencing reads were processed using DADA2, and taxonomical classification was performed using the phylogenetic placement method. Differentially abundant taxa were identified using DESeq2, while functional metagenomes based on KEGG orthology abundance were inferred using LIMMA.
RESULTS: A significantly higher microbial diversity was observed in smokeless tobacco users and smokers relative to controls (P 1.5; BH adj P

Matched MeSH terms: Bacteria/classification
The rainforest of Southeast Asia, particularly Malaysia, is endowed with several medicinal plants species

Wiart C, Akaho E, Hannah M, Yassim M, Hamimah H, Au TS, et al.

Am J Chin Med, 2005;33(4):683-5.
PMID: 16173541
Matched MeSH terms: Anti-Bacterial Agents/pharmacology*; Bacteria/drug effects*
Fulltext Biotechnological Processes in Microbial Amylase Production

Gopinath SC, Anbu P, Arshad MK, Lakshmipriya T, Voon CH, Hashim U, et al.

Biomed Res Int, 2017;2017:1272193.
PMID: 28280725 DOI: 10.1155/2017/1272193

Amylase is an important and indispensable enzyme that plays a pivotal role in the field of biotechnology. It is produced mainly from microbial sources and is used in many industries. Industrial sectors with top-down and bottom-up approaches are currently focusing on improving microbial amylase production levels by implementing bioengineering technologies. The further support of energy consumption studies, such as those on thermodynamics, pinch technology, and environment-friendly technologies, has hastened the large-scale production of the enzyme. Herein, the importance of microbial (bacteria and fungi) amylase is discussed along with its production methods from the laboratory to industrial scales.

Matched MeSH terms: Bacteria/enzymology*
Fulltext Topographically Distinguished Microbiome Taxonomy and Stress-Response Genes of Royal Belum Rainforest and Raja Muda Musa Peat Swamp Revealed through Metagenomic Inquisition

Ahmad MF, Abdullah H, Hassan MN, Jamaludin MI, Sivam A, Komatsu K, et al.

Int J Mol Sci, 2023 Jan 03;24(1).
PMID: 36614337 DOI: 10.3390/ijms24010872

Soil ecosystems are home to a diverse range of microorganisms, but they are only partially understood because no single-cell sequencing or whole-community sequencing provides a complete picture of these complex communities. Using one of such metagenomics approaches, we succeeded in monitoring the microbial diversity and stress-response gene in the soil samples. This study aims to test whether known differences in taxonomic diversity and composition are reflected in functional gene profiles by implementing whole gene sequencing (WGS) metagenomic analysis of geographically dispersed soils from two distinct pristine forests. The study was commenced by sequencing three rainforest soil samples and three peat swamp soil samples. Soil richness effects were assessed by exploring the changes in specific functional gene abundances to elucidate physiological constraints acting on different soil systems and identify variance in functional pathways relevant to soil biogeochemical cycling. Proteobacteria shows abundances of microbial diversity for 52.15% in Royal Belum Reserved Forest and 48.28% in Raja Musa; 177 out of 1,391,841 and 449 out of 3,586,577 protein coding represent acidic stress-response genes for Royal Belum and Raja Musa, respectively. Raja Musa indicates pH 2.5, which is extremely acidic. The analysis of the taxonomic community showed that Royal Belum soils are dominated by bacteria (98% in Sungai Kooi (SK), 98% in Sungai Papan (SP), and 98% in Sungai Ruok (SR), Archaea (0.9% in SK, 0.9% in SP, and 1% in SR), and the remaining were classed under Eukaryota and viruses. Likewise, the soils of Raja Muda Musa are also dominated by bacteria (95% in Raja Musa 1 (RM1), 98% in Raja Musa 2 (RM2), and 96% in Raja Musa 3 (RM3)), followed by Archaea (4% in RM1, 1% in RM2, and 3% in RM3), and the remaining were classed under Eukaryota and viruses. This study revealed that RBFR (Royal Belum Foresr Reserve) and RMFR (Raja Musa Forest Reserve) metagenomes contained abundant stress-related genes assigned to various stress-response pathways, many of which did not show any difference among samples from both sites. Our findings indicate that the structure and functional potential of the microbial community will be altered by future environmental potential as the first glimpse of both the taxonomic and functional composition of soil microbial communities.

Matched MeSH terms: Bacteria/metabolism
Fulltext Faecal DNA metabarcoding reveals novel bacterial community patterns of critically endangered Southern River Terrapin, Batagur affinis

Mohd Salleh MH, Esa Y, Ngalimat MS, Chen PN

PeerJ, 2022;10:e12970.
PMID: 35368336 DOI: 10.7717/peerj.12970

Southern River Terrapin, Batagur affinis, is a freshwater turtle listed as critically endangered on the IUCN Red List since 2000. Many studies suggest that faecal DNA metabarcoding can shield light on the host-associated microbial communities that play important roles in host health. Thus, this study aimed to characterise and compare the faecal bacterial community between captive and wild B. affinis using metabarcoding approaches. A total of seven faeces samples were collected from captive (N = 5) and wild (N = 2) adult B. affinis aseptically, crossing the East and West coast of peninsular Malaysia. The DNA was extracted from the faeces samples, and the 16S rRNA gene (V3-V4 region) was amplified using polymerase chain reaction (PCR). The amplicon was further analysed using SILVA and DADA2 pipelines. In total, 297 bacterial communities taxonomic profile (phylum to genus) were determined. Three phyla were found in high abundance in all faeces samples, namely Firmicutes (38.69%), Bacteroidetes (24.52%), and Fusobacteria (6.95%). Proteobacteria were detected in all faeces samples (39.63%), except the wild sample, KBW3. Under genus level, Cetobacteriumwas found as the most abundant genus (67.79%), followed by Bacteroides (24.56%) and Parabacteroides (21.78%). The uncultured genus had the highest abundance (88.51%) even though not detected in the BK31 and KBW2 samples. The potential probiotic genera (75.00%) were discovered to be more dominant in B. affinis faeces samples. Results demonstrated that the captive B. affinis faeces samples have a greater bacterial variety and richness than wild B. affinis faeces samples. This study has established a starting point for future investigation of the gut microbiota of B. affinis.

Matched MeSH terms: Bacteria/genetics
Fulltext Occurrence of nonfermentative gram-negative bacilli in a Malaysian hospital

Lim VKE

Singapore Med J, 1985 Dec;26(7):516-8.
PMID: 3834608

Nonfermentative Gram-negative bacilli were commonly isolated from clinical material in a Malaysian hospital over a two year period of study. Pseudomonas aeruginosa, Acinetobacter sp and other Pseudomonas were the most common organisms seen. Although these bacteria occurred regularly in clinical specimens their pathogenetic role could be established in only a small proportion of cases. Most 01 these organism were either contaminants or
commensals 01 the normal bacterial flora. It is important to interpret the isolation of a nonfermentative Gram-negative bacillus with caution, and in the light of clinical findings. Failure to do so may result in the unnecessary use of antibiotics.

Matched MeSH terms: Gram-Negative Aerobic Bacteria/isolation & purification*
Synthesis and characterization of gentamicin loaded ZSM-5 scaffold: Cytocompatibility and antibacterial activity

Nazemi N, Rajabi N, Aslani Z, Kharaziha M, Kasiri-Asgarani M, Bakhsheshi-Rad HR, et al.

J Biomater Appl, 2023 Jan;37(6):979-991.
PMID: 36454961 DOI: 10.1177/08853282221140672

Porous structure, biocompatibility and biodegradability, large surface area, and drug-loading ability are some remarkable properties of zeolite structure, making it a great possible option for bone tissue engineering. Herein, we evaluated the potential application of the ZSM-5 scaffold encapsulated GEN with high porosity structure and significant antibacterial properties. The space holder process has been employed as a new fabrication method with interconnected pores and suitable mechanical properties. In this study, for the first time, ZSM-5 scaffolds with GEN drug-loading were fabricated with the space holder method. The results showed excellent open porosity in the range of 70-78% for different GEN concentrations and appropriate mechanical properties. Apatite formation on the scaffold surface was determined with Simulation body fluid (SBF), and a new bone-like apatite layer shaping on all samples confirmed the in vitro bioactivity of ZSM-5-GEN scaffolds. Also, antibacterial properties were investigated against both gram-positive and gram-negative bacteria. The incorporation of various amounts of GEN increased the inhibition zone from 24 to 28 (for E. coli) and 26 to 37 (for S. aureus). In the culture with MG63 cells, great cell viability and high cell proliferation after 7 days of culture were determined.

Matched MeSH terms: Gram-Negative Bacteria; Gram-Positive Bacteria
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
Fulltext Effect of ocean acidification on the growth, response and hydrocarbon degradation of coccolithophore-bacterial communities exposed to crude oil

Fahmi AM, Summers S, Jones M, Bowler B, Hennige S, Gutierrez T

Sci Rep, 2023 Mar 27;13(1):5013.
PMID: 36973465 DOI: 10.1038/s41598-023-31784-5

Hydrocarbon-degrading bacteria, which can be found living with eukaryotic phytoplankton, play a pivotal role in the fate of oil spillage to the marine environment. Considering the susceptibility of calcium carbonate-bearing phytoplankton under future ocean acidification conditions and their oil-degrading communities to oil exposure under such conditions, we investigated the response of non-axenic E. huxleyi to crude oil under ambient versus elevated CO2 concentrations. Under elevated CO2 conditions, exposure to crude oil resulted in the immediate decline of E. huxleyi, with concomitant shifts in the relative abundance of Alphaproteobacteria and Gammaproteobacteria. Survival of E. huxleyi under ambient conditions following oil enrichment was likely facilitated by enrichment of oil-degraders Methylobacterium and Sphingomonas, while the increase in relative abundance of Marinobacter and unclassified Gammaproteobacteria may have increased competitive pressure with E. huxleyi for micronutrient acquisition. Biodegradation of the oil was not affected by elevated CO2 despite a shift in relative abundance of known and putative hydrocarbon degraders. While ocean acidification does not appear to affect microbial degradation of crude oil, elevated mortality responses of E. huxleyi and shifts in the bacterial community illustrates the complexity of microalgal-bacterial interactions and highlights the need to factor these into future ecosystem recovery projections.

Matched MeSH terms: Bacteria/metabolism
Fulltext Management and Mitigation of Vibriosis in Aquaculture: Nanoparticles as Promising Alternatives

Kah Sem NAD, Abd Gani S, Chong CM, Natrah I, Shamsi S

Int J Mol Sci, 2023 Aug 08;24(16).
PMID: 37628723 DOI: 10.3390/ijms241612542

Vibriosis is one of the most common diseases in marine aquaculture, caused by bacteria belonging to the genus Vibrio, that has been affecting many species of economically significant aquatic organisms around the world. The prevention of vibriosis in aquaculture is difficult, and the various treatments for vibriosis have their limitations. Therefore, there is an imperative need to find new alternatives. This review is based on the studies on vibriosis, specifically on the various treatments and their limitations, as well as the application of nanoparticles in aquaculture. One of the promising nanoparticles is graphene oxide (GO), which has been used in various applications, particularly in biological applications such as biosensors, drug delivery, and potential treatment for infectious diseases. GO has been shown to have anti-bacterial properties against both Gram-positive and Gram-negative bacteria, but no research has been published that emphasizes its impact on Vibrio spp. The review aims to explore the potential use of GO for treatment against vibriosis.

Matched MeSH terms: Gram-Negative Bacteria; Gram-Positive Bacteria
Fulltext Solvent Extraction and Identification of Active Anticariogenic Metabolites in Piper cubeba L. through ¹H-NMR-Based Metabolomics Approach

Raja Mazlan RNA, Rukayadi Y, Maulidiani M, Ismail IS

Molecules, 2018 Jul 16;23(7).
PMID: 30012946 DOI: 10.3390/molecules23071730

The aim of this study was to determine the effects of different solvents for extraction, liquid⁻liquid partition, and concentrations of extracts and fractions of Piper cubeba L. on anticariogenic; antibacterial and anti-inflammatory activity against oral bacteria. Furthermore, ¹H-Nuclear Magnetic Resonance (NMR) coupled with multivariate data analysis (MVDA) was applied to discriminate between the extracts and fractions and examine the metabolites that correlate to the bioactivities. All tested bacteria were susceptible to Piper cubeba L. extracts and fractions. Different solvents extraction, liquid⁻liquid partition and concentrations of extracts and fractions have partially influenced the antibacterial activity. MTT assay showed that P. cubeba L. extracts and fractions were not toxic to RAW 264.7 cells at selected concentrations. Anti-inflammatory activity evaluated by nitric oxide (NO) production in lipopolysaccharide (LPS) stimulated cells showed a reduction in NO production in cells treated with P. cubeba L. extracts and fractions, compared to those without treatment. Twelve putative metabolites have been identified, which are (1) cubebin, (2) yatein, (3) hinokinin, (4) dihydrocubebin, (5) dihydroclusin, (6) cubebinin, (7) magnosalin, (8) p-cymene, (9) piperidine, (10) cubebol, (11) d-germacrene and (12) ledol. Different extraction and liquid⁻liquid partition solvents caused separation in principal component analysis (PCA) models. The partial least squares (PLS) models showed that higher anticariogenic activity was related more to the polar solvents, despite some of the active metabolites also present in the non-polar solvents. Hence, P. cubeba L. extracts and fractions exhibited antibacterial and anti-inflammatory activity and have potential to be developed as the anticariogenic agent.

Matched MeSH terms: Bacteria/growth & development*
Multifunctional and theranostic hydrogels for wound healing acceleration: An emphasis on diabetic-related chronic wounds

Tehrany PM, Rahmanian P, Rezaee A, Ranjbarpazuki G, Sohrabi Fard F, Asadollah Salmanpour Y, et al.

Environ Res, 2023 Dec 01;238(Pt 1):117087.
PMID: 37716390 DOI: 10.1016/j.envres.2023.117087

Hydrogels represent intricate three-dimensional polymeric structures, renowned for their compatibility with living systems and their ability to naturally degrade. These networks stand as promising and viable foundations for a range of biomedical uses. The practical feasibility of employing hydrogels in clinical trials has been well-demonstrated. Among the prevalent biomedical uses of hydrogels, a significant application arises in the context of wound healing. This intricate progression involves distinct phases of inflammation, proliferation, and remodeling, often triggered by trauma, skin injuries, and various diseases. Metabolic conditions like diabetes have the potential to give rise to persistent wounds, leading to delayed healing processes. This current review consolidates a collection of experiments focused on the utilization of hydrogels to expedite the recovery of wounds. Hydrogels have the capacity to improve the inflammatory conditions at the wound site, and they achieve this by diminishing levels of reactive oxygen species (ROS), thereby exhibiting antioxidant effects. Hydrogels have the potential to enhance the growth of fibroblasts and keratinocytes at the wound site. They also possess the capability to inhibit both Gram-positive and Gram-negative bacteria, effectively managing wounds infected by drug-resistant bacteria. Hydrogels can trigger angiogenesis and neovascularization processes, while also promoting the M2 polarization of macrophages, which in turn mitigates inflammation at the wound site. Intelligent and versatile hydrogels, encompassing features such as pH sensitivity, reactivity to reactive oxygen species (ROS), and responsiveness to light and temperature, have proven advantageous in expediting wound healing. Furthermore, hydrogels synthesized using environmentally friendly methods, characterized by high levels of biocompatibility and biodegradability, hold the potential for enhancing the wound healing process. Hydrogels can facilitate the controlled discharge of bioactive substances. More recently, there has been progress in the creation of conductive hydrogels, which, when subjected to electrical stimulation, contribute to the enhancement of wound healing. Diabetes mellitus, a metabolic disorder, leads to a slowdown in the wound healing process, often resulting in the formation of persistent wounds. Hydrogels have the capability to expedite the healing of diabetic wounds, facilitating the transition from the inflammatory phase to the proliferative stage. The current review sheds light on the biological functionalities of hydrogels, encompassing their role in modulating diverse mechanisms and cell types, including inflammation, oxidative stress, macrophages, and bacteriology. Additionally, this review emphasizes the significance of smart hydrogels with responsiveness to external stimuli, as well as conductive hydrogels for promoting wound healing. Lastly, the discussion delves into the advancement of environmentally friendly hydrogels with high biocompatibility, aimed at accelerating the wound healing process.

Matched MeSH terms: Gram-Negative Bacteria; Gram-Positive Bacteria
Psychrobacter species enrichment as potential microplastic degrader and the putative biodegradation mechanism in Shenzhen Bay sediment, China

Ou D, Ni Y, Li W, He W, Wang L, Huang H, et al.

J Hazard Mater, 2024 Feb 15;464:132971.
PMID: 37956562 DOI: 10.1016/j.jhazmat.2023.132971

Microplastic (MP) pollution has emerged as a pressing environmental concern due to its ubiquity and longevity. Biodegradation of MPs has garnered significant attention in combatting global MP contamination. This study focused on MPs within sediments near the sewage outlet of Shenzhen Bay. The objective was to elucidate the microbial communities in sediments with varying MPs, particularly those with high MP loads, and to identify microorganisms associated with MP degradation. The results revealed varying MP abundance, ranging from 211 to 4140 items kg-1 dry weight (d. w.), with the highest concentration observed near the outfall. Metagenomic analysis confirmed the enrichment of Psychrobacter species in sediments with high MP content. Psychrobacter accounted for ∼16.71% of the total bacterial community and 41.71% of hydrocarbon degrading bacteria at the S3 site, exhibiting a higher abundance than at other sampling sites. Psychrobacter contributed significantly to bacterial function at S3, as evidenced by the Kyoto Encyclopedia of Genes and Genomes pathway and enzyme analysis. Notably, 28 enzymes involved in MP biodegradation were identified, predominantly comprising oxidoreductases, hydrolases, transferases, ligases, lyases, and isomerases. We propose a putative mechanism for MP biodegradation, involving the breakdown of long-chain plastic polymers and subsequent oxidation of short-chain oligomers, ultimately leading to thorough mineralization.

Matched MeSH terms: Bacteria/genetics

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