Objective: To obtain the diversity and abundance of fast-growing bacteria in the surface water of the northeast coast of Hainan Island in China, different cultivation methods were employed. This study also aims to provide a reference for isolating bacterial samples from seawater sources and preventing marine-derived pathogens. Methods: Based on the principles of taxonomic design, surface seawater samples were collected from six locations along the northeast coast of Hainan Island in China in March, June, October, and December 2021. Then, bacterial enrichment was performed based on traditional cultivation methods for Salmonella, Vibrio, Burkholderia pseudomallei, Actinomycetes, and general marine bacteria. After that, bacterial species identification was conducted by 16S rDNA amplicon sequencing and metagenomic sequencing. Results: A total of 1 151 fast-growing cultivable bacteria belonging to 66 genera and 213 species were identified using five different culture protocols. In different cultivation protocols, Bacillus and Klebsiella demonstrated extensive discriminatory advantages and ranked among the top genera in terms of abundance. Protocol 1 had Escherichia, Klebsiella, and Citrobacter as dominant genera. Pathogenic bacteria detected by protocol 1 included Klebsiella pneumoniae and Escherichia coli, with 37 and 29 strains respectively, while Salmonella enterica was uniquely detected with seven isolates. Proteus, Enterococcus, and Providencia were the dominant genera in protocol 2, and Proteus mirabilis was the most abundant pathogenic bacteria detected with 66 isolates. Vibrio cholerae was uniquely detected with six isolates at a higher abundance. Klebsiella, Escherichia, and Acinetobacter were the dominant genera in protocol 3, and Klebsiella pneumoniae was the most abundant pathogenic bacteria detected with 53 isolates, while Acinetobacter nosocomialis was uniquely detected with seven isolates. Vibrio and Pseudoalteromonas were the dominant genera in protocol 4, and they showed advantages in isolating and cultivating Marine-derived Vibrio. Exiguobacterium, Staphylococcus, and Bacillus were the dominant genera in protocol 5. Bacillus cereus and Lactococcus lactis were the most abundant pathogenic bacteria detected with 20 and 15 isolates, respectively, while Lactococcus lactis was uniquely detected at higher abundance. Metagenomic sequencing showed that Klebsiella pneumoniae was significantly dominant with a gene abundance of 51.11%, followed by Alcanivorax sp. at 12.57%. Conclusion: The surface water of the northeast coast of Hainan Island in China exhibits a rich diversity of bacteria, with Klebsiella pneumoniae being highly abundant in the studied area. Different cultivation methods demonstrate distinct selective advantages in culturing bacterial genera and pathogens. Therefore, it is necessary to optimize cultivation conditions for specific marine bacteria.
Humans ; Water ; Bacteria/genetics* ; Seawater/microbiology* ; Escherichia coli ; Enterococcus ; Klebsiella pneumoniae ; China

Objective: To obtain the diversity and abundance of fast-growing bacteria in the surface water of the northeast coast of Hainan Island in China, different cultivation methods were employed. This study also aims to provide a reference for isolating bacterial samples from seawater sources and preventing marine-derived pathogens. Methods: Based on the principles of taxonomic design, surface seawater samples were collected from six locations along the northeast coast of Hainan Island in China in March, June, October, and December 2021. Then, bacterial enrichment was performed based on traditional cultivation methods for Salmonella, Vibrio, Burkholderia pseudomallei, Actinomycetes, and general marine bacteria. After that, bacterial species identification was conducted by 16S rDNA amplicon sequencing and metagenomic sequencing. Results: A total of 1 151 fast-growing cultivable bacteria belonging to 66 genera and 213 species were identified using five different culture protocols. In different cultivation protocols, Bacillus and Klebsiella demonstrated extensive discriminatory advantages and ranked among the top genera in terms of abundance. Protocol 1 had Escherichia, Klebsiella, and Citrobacter as dominant genera. Pathogenic bacteria detected by protocol 1 included Klebsiella pneumoniae and Escherichia coli, with 37 and 29 strains respectively, while Salmonella enterica was uniquely detected with seven isolates. Proteus, Enterococcus, and Providencia were the dominant genera in protocol 2, and Proteus mirabilis was the most abundant pathogenic bacteria detected with 66 isolates. Vibrio cholerae was uniquely detected with six isolates at a higher abundance. Klebsiella, Escherichia, and Acinetobacter were the dominant genera in protocol 3, and Klebsiella pneumoniae was the most abundant pathogenic bacteria detected with 53 isolates, while Acinetobacter nosocomialis was uniquely detected with seven isolates. Vibrio and Pseudoalteromonas were the dominant genera in protocol 4, and they showed advantages in isolating and cultivating Marine-derived Vibrio. Exiguobacterium, Staphylococcus, and Bacillus were the dominant genera in protocol 5. Bacillus cereus and Lactococcus lactis were the most abundant pathogenic bacteria detected with 20 and 15 isolates, respectively, while Lactococcus lactis was uniquely detected at higher abundance. Metagenomic sequencing showed that Klebsiella pneumoniae was significantly dominant with a gene abundance of 51.11%, followed by Alcanivorax sp. at 12.57%. Conclusion: The surface water of the northeast coast of Hainan Island in China exhibits a rich diversity of bacteria, with Klebsiella pneumoniae being highly abundant in the studied area. Different cultivation methods demonstrate distinct selective advantages in culturing bacterial genera and pathogens. Therefore, it is necessary to optimize cultivation conditions for specific marine bacteria.
Humans ; Water ; Bacteria/genetics* ; Seawater/microbiology* ; Escherichia coli ; Enterococcus ; Klebsiella pneumoniae ; China

We present five patients with vibrio necrotising fasciitis, a lethal and disabling disease. Two of these patients had a history of exposure to either warm seawater or raw/live seafood, three had underlying chronic liver disease, and four presented with hypotension and fever. There were three deaths and four patients required intensive care unit stays. Among the two survivors, one had high morbidity. Only one patient met the criteria of Laboratory Risk Indicator for Necrotising Fasciitis score > 6. A clinician should suspect possible vibrio necrotising fasciitis if the following are present: contact with fresh seafood/warm seawater, a known history of chronic liver disease and pain that is out of proportion to cutaneous signs. All patients must be managed via intensive care in high dependency units. We recommend a two-step surgical protocol for patient management involving an initial local debridement, followed by a second-stage radical debridement and skin grafting.
Aged ; Aged, 80 and over ; Debridement ; End Stage Liver Disease ; complications ; Fasciitis, Necrotizing ; diagnosis ; microbiology ; surgery ; Female ; Fever ; complications ; Hepatitis B ; complications ; Humans ; Hypotension ; complications ; Male ; Middle Aged ; Retrospective Studies ; Risk Factors ; Seafood ; Seawater ; Severity of Illness Index ; Singapore ; Skin Transplantation ; Vibrio ; Vibrio Infections ; diagnosis ; surgery

Chemical examination of an EtOAc extract of cultured Aspergillus versicolor fungus from deep-sea sediments resulted in the isolation of four xanthones, eight anthraquinones and five alkaloids, including a new xanthone, oxisterigmatocystin D (1) and a new alkaloid, aspergillusine A (13). High resolution electron impact mass spectrometry (HR-EI-MS), FT-IR spectroscopy, and NMR techniques were used to elucidate the structures of these compounds, and the absolute configuration of compound 1 was established by its NMR features and coupling constant. Furthermore, the biosynthesis pathway of these xanthones and anthraquinones were deduced, and their antioxidant activity and cytotoxicity in human cancer cell lines (HTC-8, Bel-7420, BGC-823, A549, and A2780) were evaluated. The trolox equivalent antioxidant capacity (TEAC) assay indicated most of the xanthones and anthraquinones possessing moderate antioxidant activities. The Nrf2-dependent luciferase reporter gene assay revealed that compounds 6, 7, 9, and 12 potentially activated the expression of Nrf2-regulated gene. In addition, compounds 5 and 11 showed weak cytotoxicity on A with the IC values of 25.97 and 25.60 μmol·L, respectively.
Anthraquinones ; Antioxidants ; chemistry ; isolation & purification ; metabolism ; pharmacology ; Aspergillus ; chemistry ; genetics ; isolation & purification ; metabolism ; Cell Line, Tumor ; Cell Survival ; drug effects ; Gene Expression ; drug effects ; Humans ; Magnetic Resonance Spectroscopy ; Molecular Structure ; NF-E2-Related Factor 2 ; genetics ; metabolism ; Seawater ; microbiology ; Spectroscopy, Fourier Transform Infrared ; Xanthones ; chemistry ; isolation & purification ; metabolism ; pharmacology

We isolated and identified the symbiotic and adnascent microorganisms from an unidentified sponge collected from 10-meter-deep seawater of the Paracel Islands in China. A total of 16 strains were obtained and identified. Through bacteriostatic activity assay, one of the strains, Dermacoccus sp. X4, was found to effectively inhibit the growth of Staphylococcus aureus. Subsequently, its secondary metabolites were purified by silica gel partition, octadecylsilane (ODS) reverse phase, Sephadex™LH-20 size exclusion, and C18 reverse phase chromatography. Using liquid chromatography, mass spectrometry, and nuclear magnetic resonance, three of the purified compounds were structurally characterized to be one 3-(4-hydroxybenzyl) hexahydropyrrolo [1,2-a]pyrazine-1,4-dione and two indole acid glycerides. This is the first report about indole acid glyceride isolated from microbial secondary metabolites, enriching marine drug candidate resources.
Actinomycetales ; chemistry ; Animals ; China ; Chromatography, Liquid ; Indoles ; isolation & purification ; pharmacology ; Magnetic Resonance Spectroscopy ; Mass Spectrometry ; Porifera ; microbiology ; Seawater ; Secondary Metabolism ; Staphylococcus aureus ; drug effects

Marine ecological niches have recently been described as "particularly promising" sources for search of new antimicrobials to combat antibiotic-resistant strains of pathogenic microorganisms. Marine organisms are excellent sources for many industrial products, but they are partly explored. Over 30 000 compounds have been isolated from marine sources. Bacteria, fungi, and cyanobacteria obtained from various marine sources secret several industrially useful bioactive compounds, possessing antibacterial, antifungal, and antimycobacterial activities. Sustainable cultivation methods for promising marine organisms and biotechnological processes for selected compounds can be developed, along with the establishment of biosensors for monitoring the target compounds. The semisynthetic modifications of marine-based bioactive compounds produce their new derivatives, structural analogs and mimetics that could serve as novel lead compounds against resistant pathogens. The present review focuses on promising antimicrobial compounds isolated from marine microbes from 1991-2013.
Anti-Infective Agents ; chemistry ; metabolism ; pharmacology ; Bacteria ; chemistry ; isolation & purification ; metabolism ; Fungi ; chemistry ; isolation & purification ; metabolism ; Seawater ; microbiology

Two new compounds, (22E)-25-carboxy-8β,14β-epoxy-4α,5α-dihydroxyergosta-2,22-dien-7-one (1) and fusidione (3), along with two known compounds, 5α,8α-epidioxy ergosta-6,22-diene-3β-ol (2) and microperfuranone (4), were isolated from the fermentation products of the marine-sourced fungus Acremonium fusidioides RZ01. The structures of compounds 1 and 3 were elucidated by extensive spectroscopic methods, especially 2D NMR, and their absolute configurations were suggested on the basis of the circular dichroism spectral analysis and the NOESY data. Both new compounds showed inhibitory activity against HL-60 cells with IC values being16.6 and 44.9 μmol·L, respectively.
Acremonium ; chemistry ; classification ; isolation & purification ; metabolism ; Antineoplastic Agents ; chemistry ; isolation & purification ; pharmacology ; Cell Proliferation ; drug effects ; Fermentation ; HL-60 Cells ; Humans ; Magnetic Resonance Spectroscopy ; Molecular Structure ; Seawater ; microbiology

Endophytic fungi which reside in the tissue of mangrove plants seem to play an important role in the discovery of new biologically active substances. During the course of screening for the antimicrobial metabolites from the endophytic fugus Penicillium sp. FJ-1 of mangrove plant Avicennia marina, a new aurone glycoside (1) was isolated by repeated column chromatography on silica gel and recrystallization methods. The structure of 1 was elucidated as (Z)-7,4'-dimethoxy-6-hydroxy-aurone-4-O-β-glucopyranoside, on the basis of spectroscopic analysis. Compound 1 exhibited antifungal activity against Candida sp., with the potency comparable to amphotericin B and much better than fluconazole. Compound 1 can also inhibit extracellular phospholipase secretion in a concentration-dependent manner.
Antifungal Agents ; chemistry ; isolation & purification ; metabolism ; pharmacology ; Benzofurans ; chemistry ; isolation & purification ; metabolism ; pharmacology ; Candida ; drug effects ; Glycosides ; chemistry ; isolation & purification ; metabolism ; pharmacology ; Molecular Structure ; Penicillium ; chemistry ; genetics ; isolation & purification ; metabolism ; Seawater ; microbiology

To investigate cytotoxic secondary metabolites of Micrococcus sp. R21, an actinomycete isolated from a deep-sea sediment (-6 310 m; 142 degrees 19. 9' E, 10 degrees 54. 6' N) of the Western Pacific Ocean, column chromatography was introduced over silica gel, ODS, and Sephadex LH-20. As a result, eight compounds were obtained. By mainly detailed analysis of the NMR data, their structures were elucidated as cyclo(4-hydroxy-L-Pro-L-leu) (1), cyclo(L-Pro-L-Gly) (2), cyclo( L-Pro-L-Ala) (3), cyclo( D-Pro-L-Leu) (4), N-β-acetyltryptamine (5), 2-hydroxybenzoic acid (6), and phenylacetic acid (7). Compound 1 exhibited weak cytotoxic activity against RAW264. 7 cells with IC50 value of 9.1 μmol x L(-1).
Animals ; Biological Factors ; chemistry ; isolation & purification ; metabolism ; pharmacology ; Cell Survival ; drug effects ; Macrophages ; cytology ; drug effects ; Magnetic Resonance Spectroscopy ; Mass Spectrometry ; Mice ; Micrococcus ; chemistry ; genetics ; isolation & purification ; metabolism ; Molecular Structure ; Phylogeny ; RAW 264.7 Cells ; Seawater ; microbiology ; Secondary Metabolism

A new steroid with a long cross-conjugation structure, 15a-hydroxy-(22E, 24R)-ergosta-3, 5, 8 (14), 22-tetraen-7-one (1), was isolated from the marine-derived fungus Aspergillus aculeatus. Its structure was established by the extensive spectroscopic analyses, and its cytotoxicities against P388, HL-60, and PC-3 cell lines were measured in vitro.
Animals ; Aspergillus ; chemistry ; Cell Line, Tumor ; drug effects ; Cholestenones ; chemistry ; isolation & purification ; pharmacology ; HL-60 Cells ; drug effects ; Humans ; Inhibitory Concentration 50 ; Molecular Structure ; Seawater ; microbiology