Nutrient Deficiencies Impact on the Cellular and Metabolic Responses of Saxitoxin Producing : A Transcriptomic Perspective.

Dinoflagellate Halim is commonly associated with harmful algal blooms (HABs) in tropical marine waters due to its saxitoxin production. However, limited information is available regarding the cellular and metabolic changes of in nutrient-deficient environments. To fill this gap, our study aimed to investigate the transcriptomic responses of under nitrogen and phosphorus deficiency.

sp. nov: A new bacterium isolated from the toxic diatom.

sp. nov strain P2D13-UKM is a new species of Gram-positive bacteria isolated from a toxic diatom, . It is a halophilic aerobic, oxidase-negative, catalase-positive, circular, and colonies with white colour.

Harmful Microalgae Detection: Biosensors versus Some Conventional Methods.

In the last decade, there has been a steady stream of information on the methods and techniques available for detecting harmful algae species. The conventional approaches to identify harmful algal bloom (HAB), such as microscopy and molecular biological methods are mainly laboratory-based and require long assay times, skilled manpower, and pre-enrichment of samples involving various pre-experimental preparations. As an alternative, biosensors with a simple and rapid detection strategy could be an improvement over conventional methods for the detection of toxic algae species.

Insights into Nutrient Acquisition, Metabolism and Saxitoxin Biosynthesis through Comprehensive Transcriptome Survey.

The toxin-producing dinoflagellate is responsible for the outbreaks of harmful algae bloom (HABs). It is a widely distributed species and is responsible for producing paralytic shellfish poisoning toxins. However, the information associated with the environmental adaptation pathway and toxin biosynthesis in this species is still lacking.

Pathogenic hitchhiker diversity on international ships' ballast water at West Malaysia port.

This study investigates bacterial diversity and potential pathogens in the international ships' ballast water at Tanjung Pelepas Port, Malaysia, using 16S rRNA amplicon sequencing. Thirty-four bacterial phylum, 305 families, 577 genera, and 941 species were detected in eight ballast water samples of different origins. The similarity of the bacterial composition between samples was found to be random and not tied to geographical locations.

Characterization of putative pathogenic isolated from ballast water.

Background And Aim: is ubiquitous in marine-associated environments and has been increasingly recognized as a significant human pathogen that can cause serious infections mainly associated with exposure to seawater and ingestion of raw seafood. This study aimed to isolate and characterize from ballast water of ships berthed at Port Klang, Malaysia.

Materials And Methods: Ballast water was sampled from nine ships docked at Port Klang, Malaysia.

anti-biofilm activity of bacteriocin from a marine sp. strain Sh10 against .

Background And Objectives: Biofilm formed by strains is one of the most important medical problems especially in the case of device-related urinary tract infections. This study was conducted to evaluate the bacteriocin produced by a marine isolate of sp. Sh10, for it's inhibitory activity against pre-formed biofilm and in interference with the biofilm-forming of two biofilm-producing bacteria ( UCa4 and UCe1).

Biosynthesis of Saxitoxin in Marine Dinoflagellates: An Omics Perspective.

Saxitoxin is an alkaloid neurotoxin originally isolated from the clam in 1957. This group of neurotoxins is produced by several species of freshwater cyanobacteria and marine dinoflagellates. The saxitoxin biosynthesis pathway was described for the first time in the 1980s and, since then, it was studied in more than seven cyanobacterial genera, comprising 26 genes that form a cluster ranging from 25.

Isolation, detection of virulence genes, antibiotic resistance genes, plasmid profile, and molecular typing among isolated in Malaysian seawater from recreational beaches and fish.

Background And Aim: Despite the importance of the global emergence of infections worldwide, there has been scanty information on its occurrence in Malaysian seawaters and fish. This study aimed to determine the occurrence of isolates using polymerase chain reaction targeted at toxin operon gene, thermostable direct hemolysin (), and -related hemolysin genes and to determine antibiotic resistance pattern, genes, and plasmid profile of from Malaysian seawaters and fish.

Materials And Methods: Samples were collected from four recreational beaches in Malaysia (Port Klang; Bachok; Port Dickson; and Mersing).

Rapid determination of kappa-carrageenan using a biosensor from immobilized Pseudomonas carrageenovora cells.

A potentiometric whole cell biosensor based on immobilized marine bacterium, Pseudomonas carrageenovora producing κ-carrageenase and glycosulfatase enzymes for specific and direct determination of κ-carrageenan, is described. The bacterial cells were immobilized on the self-plasticized hydrogen ion (H+)-selective acrylic membrane electrode surface to form a catalytic layer. Hydrogen ionophore I was incorporated in the poly(n-butyl acrylate) [poly(nBA)] as a pH ionophore.

An ultrasensitive hollow-silica-based biosensor for pathogenic Escherichia coli DNA detection.

A novel electrochemical DNA biosensor for ultrasensitive and selective quantitation of Escherichia coli DNA based on aminated hollow silica spheres (HSiSs) has been successfully developed. The HSiSs were synthesized with facile sonication and heating techniques. The HSiSs have an inner and an outer surface for DNA immobilization sites after they have been functionalized with 3-aminopropyltriethoxysilane.

Population dynamics, antibiotics resistance and biofilm formation of Aeromonas and Vibrio species isolated from aquatic sources in Northern Malaysia.

This study aimed to compare population dynamics, antibiotic resistance and biofilm formation of Aeromonas and Vibrio species from seawater and sediment collected from Northern Malaysia. Isolates with different colony morphology were characterized using both biochemical and molecular methods before testing for antibiotic resistance and biofilm formation. Results obtained from this study showed that in Kedah, the population of Aeromonas isolated from sediment was highest in Pantai Merdeka (8.

Antibiotic resistance profiling and phenotyping of species isolated from aquatic sources.

This study aimed to investigate antibiotics resistance pattern and phenotyping of species isolated from different aquatic sources in Melaka, Malaysia. A total of 53 species were isolated from the following sources: sediment ( = 13), bivalve ( = 10), sea cucumber ( = 16) and sea water ( = 14) and resistance to 12 antibiotics - Tetracycline (30 μg), Kanamycin (30 μg), Oxytetracycline (30 μg), Ampicillin (10 μg), Streptomycin (10 μg), Gentamicin (10 μg), Sulphamethoxazole (25 μg), Nalixidic acid (30 μg), Trimethoprim (1.25 μg), Novobiocin (5 μg), Penicilin (10 μg) and Chloramphenicol (10 μg) was tested.

Pathogenicity of Aeromonas hydrophila isolated from the Malaysian Sea against coral (Turbinaria sp.) and sea bass (Lates calcarifer).

A study was carried out to determine the pathogenicity (hemolytic activity) on corals (Turbinaria sp.) and sea bass (Lates calcarifer) of Aeromonas hydrophila from water, sediment, and coral. Samples were collected from coastal water and coral reef areas.

Loktanella spp. Gb03 as an algicidal bacterium, isolated from the culture of Dinoflagellate Gambierdiscus belizeanus.

Aim: Bacteria associated with harmful algal blooms can play a crucial role in regulating algal blooms in the environment. This study aimed at isolating and identifying algicidal bacteria in Dinoflagellate culture and to determine the optimum growth requirement of the algicidal bacteria, Loktanella sp. Gb-03.

Secondary metabolites produced by marine streptomyces as antibiofilm and quorum-sensing inhibitor of uropathogen Proteus mirabilis.

Quorum-sensing regulates bacterial biofilm formation and virulence factors, thereby making it an interesting target for attenuating pathogens. In this study, we investigated anti-biofilm and anti-quorum-sensing compounds from secondary metabolites of halophiles marine streptomyces against urinary catheter biofilm forming Proteus mirabilis without effect on growth viability. A total of 40 actinomycetes were isolated from samples collected from different places in Iraq including marine sediments and soil samples.

An optical biosensor from green fluorescent Escherichia coli for the evaluation of single and combined heavy metal toxicities.

A fluorescence-based fiber optic toxicity biosensor based on genetically modified Escherichia coli (E. coli) with green fluorescent protein (GFP) was developed for the evaluation of the toxicity of several hazardous heavy metal ions. The toxic metals include Cu(II), Cd(II), Pb(II), Zn(II), Cr(VI), Co(II), Ni(II), Ag(I) and Fe(III).

Microencapsulated Aliivibrio fischeri in alginate microspheres for monitoring heavy metal toxicity in environmental waters.

In this article a luminescence fiber optic biosensor for the microdetection of heavy metal toxicity in waters based on the marine bacterium Aliivibrio fischeri (A. fischeri) encapsulated in alginate microspheres is described. Cu(II), Cd(II), Pb(II), Zn(II), Cr(VI), Co(II), Ni(II), Ag(I) and Fe(II) were selected as sample toxic heavy metal ions for evaluation of the performance of this toxicity microbiosensor.

Biofilm formation, gel and esp gene carriage among recreational beach Enterococci.

Biofilm production, gel and esp gene carriage was enumerated among forty six vancomycin resistant enterococci (VRE) and vancomycin susceptible enterococci (VSE) beach isolates. A higher proportion (61.54%) of biofilm producers was observed among beach sand as compared to beach water enterococci isolates (30%) indicating that enterococci within the sand column may be more dependent on biofilm production for survival than their beach water counterparts.

Application of multilocus sequence analysis for molecular characterization of enterococci with virulence factors recovered from a tropical recreational beach.

Partial gene sequences of phenylalanyl-tRNA synthase alpha subunit (pheS) and RNA polymerase alpha subunit (rpoA) were evaluated for species delineation and detection of recombination among enterococci populations recovered from a bathing beach impacted by low tide river flow. At inter-species level, a maximum similarity of 86.5% and 94.

Occurrence of Enterococcus species with virulence markers in an urban flow-influenced tropical recreational beach.

Median enterococci counts of beach water samples gradually increased at statistically significant levels (χ2: 26.53, df: 4; p<0.0001) with increasing proximity to river influx.

Validation of the Enterococci indicator for bacteriological quality monitoring of beaches in Malaysia using a multivariate approach.

There is currently no established bacteriological beach quality monitoring (BQM) program in place in Malaysia. To initiate cost-effective, sustainable bacteriological BQM schemes for the ultimate goal of protecting public health, policy decision makers need to be provided robust, indigenous empirical findings that validate appropriate water quality parameters for inclusion in such monitoring programs. This is the first study that assesses the validity of enterococci as an ideal indicator for bacteriological BQM in Malaysia using a multivariate approach.

Pseudomonas putida Strain FStm2 Isolated from Shark Skin: A Potential Source of Bacteriocin.

Bacteriocin-producing Pseudomonas putida strain FStm2 isolated from shark showed broad range of antibacterial activity against all pathogens tested except Bacillus subtilis ATCC11774, MRSA N32064, Proteus mirabilis ATCC12453, Enterococcus faecalis ATCC14506, Salmonella typhimurium ATCC51312, Salmonella mutan ATCC25175, and Aeromonas hydrophila Wbf314. Of the three growth media tested in this study, TSB was observed to support the bacteriocin activity the most. While the highest bacteriocin activity was observed for media supplemented with 1 % NaCl, there was an observed reduction in bacteriocin activity with increasing salt concentration.

Influence of culture conditions and medium composition on the production of antibacterial compounds by marine Serratia sp. WPRA3.

This study was undertaken to investigate the influence of culture conditions and medium components on production of antibacterial compounds by Serratia sp. WPRA3 (JX020764) which was isolated from marine water of Port Dickson, Malaysia. Biochemical, morphological, and molecular characteristics suggested that the isolate is a new candidate of the Serratia sp.

High-level aminoglycoside resistance and virulence characteristics among Enterococci isolated from recreational beaches in Malaysia.

We report the first study on the occurrence of high-level aminoglycoside-resistant (HLAR) Enterococci in coastal bathing waters and beach sand in Malaysia. None of the encountered isolates were resistant to high levels of gentamicin (500 μg/mL). However, high-level resistance to kanamycin (2,000 μg/mL) was observed in 14.