The biological nitrogen removal technology utilizing heterotrophic nitrification-aerobic denitrification (HN-AD) bacteria has shown effectiveness in wastewater treatment. However, the nitrogen removal efficiency of HN-AD bacteria significantly decreases as the salinity increases. To tackle the challenge of treating high-salt and high-nitrogen wastewater, we isolated a moderately halophilic HN-AD strain 5505 from a salt lake in Xinjiang. The strain was identified based on morphological, physiological, and biochemical characteristics and the 16S rRNA gene sequence. Single-factor experiments were carried out with NH₄⁺-N, NO₃^--N, and NO₂^--N as sole or mixed nitrogen sources to study the nitrifying effect, denitrifying effect, and nitrogen metabolism pathway of the strain. The strain was identified as Halomonas sp.. It can grow in the presence of 1%-25% (W/V) NaCl and exhibited efficient nitrogen removal ability in the presence of 3%-8% NaCl. At the optimal NaCl concentration (8%), the strain showed the NH₄⁺-N, NO₃^--N and NO₂^--N removal rates of 100.0%, 94.11% and 74.43%, respectively. Strain 5505 removed inorganic nitrogen mainly by assimilation, which accounted for over 62.68% of total nitrogen removal. In the presence of mixed nitrogen sources, strain 5505 showed a preference for utilizing ammonia, with a potential HN-AD pathway of NH₄⁺→NH₂OH→NO₂^-→NO₃^-→NO₂^-→NO/N₂O/N₂. The findings provide efficient salt-tolerant bacterial resources, enhance our understanding of biological nitrogen removal, and contribute to the nitrogen removal efficiency improvement in the treatment of high-salt and high-nitrogen wastewater.
Halomonas/classification* ; Nitrogen/isolation & purification* ; Denitrification ; Nitrification ; Wastewater/microbiology* ; Aerobiosis ; Biodegradation, Environmental ; Salinity

ObjectiveTo investigate the features of liver histopathological damage in patients with indeterminate phase of chronic HBV infection， as well as the timing for initiating antiviral therapy in such patients. MethodsA retrospective screening was performed for the patients with chronic HBV infection who were hospitalized in The Fifth Medical Center of Chinese PLA General Hospital and underwent liver biopsy from March 2018 to April 2022， among whom the patients who met the criteria for indeterminate phase defined in Chinese guidelines for chronic hepatitis B prevention and treatment （2022 edition） were enrolled， and their clinical data were collected. Liver histopathological stage was determined using the Scheuer scoring system， with stages 0 — 4 for inflammation grade （G） and stages 0 — 4 for fibrosis degree （S）， and the patients were divided into groups based on the presence of significant necroinflammation （≥G2） and significant liver fibrosis （≥S2）. The independent samples t-test was used for comparison of normally distributed continuous data between two groups， and the Mann-Whitney U test was used for comparison of non-normally distributed continuous data between two groups； the chi-square test or the Fisher’s exact test was used for comparison of categorical data between two groups. A Spearman’s rank correlation analysis was used to investigate the correlation between liver histopathology and clinical factors， and the Logistic regression model was used to identify the independent influencing factors for significant necroinflammation and liver fibrosis. ResultsA total of 271 patients with indeterminate phase of chronic HBV infection were enrolled， among whom 61 （22.5%） had significant necroinflammation （≥G2） and 124 （45.8%） had significant liver fibrosis （≥S2）. The Logistic regression analysis showed that alanine aminotransferase ≥30 U/L （for male patients） or ≥19 U/L （for female patients） （odds ratio ［OR］=2.69， 95% confidence interval ［CI］： 1.39 — 5.21， P=0.003）， HBV DNA ≥2 000 IU/mL （OR=2.75， 95%CI： 1.38 — 5.48， P=0.004）， and liver stiffness measurement （LSM） ≥6.0 kPa （OR=4.57， 95%CI： 2.17 — 9.62， P<0.001） were independent risk factors for significant inflammation. HBV DNA ≥2 000 IU/mL （OR=1.82， 95%CI： 1.01 — 3.32， P=0.049） and LSM ≥6.0 kPa （OR=2.06， 95%CI： 1.23 — 3.43， P=0.006） were independent influencing factors for significant liver fibrosis. ConclusionAmong the patients with indeterminate phase of chronic HBV infection， a substantial proportion of patients have significant liver histopathological damage. Antiviral therapy should be initiated in a timely manner for patients with high-risk factors.

Objective:To investigate the expression of protein kinase D2(PRKD2)in bladder cancer(BLCA)tissue using bioinformatics analysis method and its effect on the prognosis of BLCA patients,and to clarify the role of PRKD2 in the occurrence and development of BLCA.Methods:The data from 9 normal bladder samples,19 BLCA paracancerous samples,and 407 BLCA tumor samples were downloaded from the UCSC Cancer Genome Database.The Mann-Whitney U test was applied to analyze the difference in expression of PRKD2 mRNA in BLCA tumor and normal bladder tissues,and the Human Protein Atlas(HPA)database was used for proteomic validation.DESeq2 package in R software was applied to screen the differentially expressed genes(DEGs)in BLCA tissue in PRKD2 low-and high-expression groups.The co-expression heatmaps of PRKD2 were plotted using the ggplot2 package,Gene Ontology(GO)and Kyoto Encyclopedia of Genes and Genomes(KEGG)were used for functional annotation analysis and pathway enrichment analysis of DEGs,and Gene Set Enrichment Analysis(GSEA)was used to obtain the gene sets that were significantly enriched for DEGs.The BLCA samples were divided into low-and high-expression groups according to the expression level of PRKD2,and the correlations between PRKD2 expression and immune cell infiltration in the BLCA patients were analyzed with GSVA package.The relationship between PRKD2 and prognosis of BLCA patients was further analyzed using the survival package and the survminer package.The PRKD2 gene mutations in BLCA tissue were analyzed using the cBioPortal database.The cystitis,bladder polyp and BLCA tissues were collected,and the expression levels of interleukin-17F(IL-17F)protein in BLCA and control tissues were detected using immunohistochemical staining technique.Results:PRKD2 was highly expressed in a variety of malignant tumors,and the expression levels of PRKD2 mRNA and protein in BLCA tissue were significantly increased compared with those in normal bladder tissue(P＜0.05).Single gene differential analysis of PRKD2 yielded a total of 1 058 DEGs,of which a total of 29 genes were up-regulated and 1 029 were down-regulated.The results of GO functional enrichment analysis showed that DEGs were mainly enriched in the biological process(BP),such as chemical stimuli involved in sensory perception,Cajal body,and endopeptidase inhibitor activity.The results of KEGG pathway analysis showed that DEGs were mainly enriched in the pathway of Staphylococcus aureus infection and the pathway of maturity onset diabetes of the young.GSEA analysis showed that DEGs were mainly enriched in the Notch signaling pathway,the retinoic acid-inducible gene-Ⅰ(RIG-Ⅰ)-like receptor signaling pathway,the cytoplasmic DNA screening pathway,the base excision repair signaling pathway,natural killer(NK)cell-mediated cytotoxicity signaling pathway and T cell receptor signaling pathway.The results of immune infiltration analysis indicated that the expression of PRKD2 was positively correlated with five types of cells,such as activated dendritic cells(aDC),NK CD56dim cells and central memory T cells(Tcm)(P＜0.05),and negatively correlated with three types of immune cells,including macrophages,effector memory T cells(Tem)and plasmacytoid dendritic cells(pDC)(P＜0.05).The clinical characteristic subgroup analysis results showed that the expression levels of PRKD2 mRNA in BLCA patients who were over 70 years old and developed lymphovascular invasion were decreased(P＜0.05);the overall survival(OS),disease-specific survival(DSS)and progression-free interval(PFI)in the BLCA patients with PRKD2 high expression were significantly longer than those with PRKD2 low expression(P＜0.05).The univariate and multivariate Cox analyses indicated that distant metastasis,primary therapy outcome and clinicopathologic stage were the important factors affecting BLCA prognosis.About 9％patients had PRKD2 gene mutations,including missense mutation,gene amplification,mRNA low or high expression,and multi-motif mutation.The immunohistochemistry results showed that the expression level of IL-17F protein in BLCA tissue was significantly higher than that in cystitis tissue(P＜0.05).Conclusion:The expression level of PRKD2 in BLCA tissue is obviously increased,which could up-regulate the expression of IL-17F protein,and the decrease of PRKD2 protein expression may be a potential factor for the poor prognosis of BLCA patients.

Objective:To explore the clinical efficacy of percutaneous balloon compression (PBC) in the treatment of trigeminal neuralgia (TN) based on the double difference (DID) model.Methods:A retrospective case - control study method was adopted to analyze the general data of 130 patients with trigeminal neuralgia (TN) who were treated in the Department of Neurosurgery of Hebei General Hospital from January 2022 to October 2023. Among them, 49 were males and 81 were females. The age was (53.28±11.67) years, ranging from 25 to 80 years old. According to different treatment methods, the patients were divided into an experimental group ( n=63) and a control group ( n=67). Patients in the experimental group were given percutaneous balloon compression (PBC) treatment, while those in the control group were treated with conservative drug therapy. Propensity score matching method was used for 1∶1 matching. After matching, there were 52 cases in each group. The general data of the two groups were compared. The visual analogue scale (VAS), 36-item short form health survey (SF-36) score, Hamilton depression rating scale (HAMD) score, Hamilton anxiety rating scale (HAMA) score, 5-hydroxytryptamine, neuropeptide P, inflammatory factor interleukin-1 (IL-1), tumor necrosis factor-α (TNF-α) before and after treatment, as well as the clinical efficacy of the two groups of patients were comparatively analyzed. Meanwhile, the incidence of postoperative complications in the two groups was compared. The generalized estimating equation (GEE) model was used to analyze the influencing factors of clinical efficacy, and the difference-in-differences (DID) model was used to evaluate the efficacy before and after treatment. Measurement data conforming to the normal distribution were expressed as mean±standard deviation ( ± s), and the t-test was used for comparison between groups; the chi- square test was used for comparison between count data. Results:After treatment, the VAS, SF-36 score, HAMD score, HAMA score, 5-hydroxytryptamine level, neuropeptide P level, IL-1 level, and TNF-α level in the experimental group were (2.98±0.83) points, (75.56±1.18) points, (7.2±0.83) points, (7.15±0.85) points, (76.34±5.47) ng/mL, (50.95±11.01) pg/mL, (29.45±7.08) ng/L, and (21.18±3.55) ng/L respectively. In the control group, there were (3.63±0.95) points, (73.23±1.13) points, (7.98±0.80) points, (8.04±0.84) points, (186.31±11.61) ng/mL, (86.52±13.32) pg/mL, (34.47±6.58) ng/L, and (26.36±5.80) ng/L, respectively. The differences between the two groups were statistically significant ( P<0.05).The cure rate and the total incidence of postoperative complications in the experimental group were 55.77% and 13.46% respectively, while in the control group, they were 40.38% and 30.77% respectively. The differences between the two groups were statistically significant ( P<0.05).The results of the GEE model analysis showed that age, course of disease, VAS, SF-36 score, HAMA score, HAMD score, 5-hydroxytryptamine level, neuropeptide P level, IL-1 level, TNF-α level, treatment method, and the long - diameter ratio of FO significantly affected the clinical efficacy of patients ( P<0.05).The results of the DID model showed that the experimental group was superior to the control group in improving the VAS, SF-36 score, HAMD score, HAMA score, 5-hydroxytryptamine level, neuropeptide P level, IL-1 level, and TNF-α level( P<0.05). Conclusion:PBC can significantly improve the VAS, SF-36 score, HAMD score, HAMA score, 5-hydroxytryptamine, neuropeptide P, IL-1, TNF-α, and incidence of complications in patients with TN. It can also improve the psychological status and quality of life of patients.

Objective To observe the anti-asthma mechanism of berberine.Methods Thirty-two SD rats were randomly divided into normal group,model group,berberine group and Montelukast group,eight rats in each group.Except for the normal group,an allergic asthma model was constructed by ovalbumin(OVA)induction method in rats of all other groups.After successful modeling,seven days of drug administration was performed.The inflammatory cells(including lymphocytes,neutrophil,macrophages and eosinophils)were counted in the collected bronchoalveolar lavage fluid(BALF)under microscope,and the serum ovalbumin-specific immunoglobulin E(sIgE)and total immunoglobulin E(IgE)levels were detected by enzyme-linked immunosorbent assay(ELISA),and the levels of T helper cell(Th)1-related cytokines[interferon(IFN)-γ,interleukin(IL)-2]and Th2-related cytokines(IL-4,IL-5,IL-10 and IL-13)in BALF were detected by ELISA,and the mRNA expression levels of IFN-γ,IL-2,and IL-4,IL-5,IL-10 and IL-13 in lung tissues were detected by real-time fluorescence quantitative polymerase chain reaction(RT-qPCR),and the histopathologic feature of lung tissues was observed by hematoxylin-eosin(HE)staining.Results Compared with the normal group,the counts of eosinophils,macrophages,neutrophils,lymphocytes and total cells in the model group were increased,the levels of serum sIgE and total IgE were elevated,and the levels of Th2-related cytokines such as IL-4,IL-5,IL-10 and IL-13 in BALF and their mRNA expressions in lung tissue were significantly increased,and the levels of Th1-related cytokines IFN-γ and IL-2 in BALF and their mRNA expression levels in lung tissue were significantly reduced,the difference being statistically significant(P<0.05 or P<0.01),and the HE pathological staining results of lung tissue showed that there was a large number of inflammatory cells infiltration around bronchial and alveolar cells,and the smooth muscle layer and the wall of airways were thickened.Compared with the model group,all of the above statistical indexes were improved in the berberine group and the Montelukast group(P<0.05 or P<0.01),and the inflammatory cell infiltration was significantly reduced,and airway wall and smooth muscle layer were attenuated in lung tissue,there being no significant differences between the two treatment groups(P>0.05).Conclusion The mechanism of anti-asthma action of berberine is related to the regulation of Th1/Th2 cytokine imbalance.

【Objective】 To explore the effects and mechanism of p38 mitogen activated protein kinase (MAPK) pathway on the formation of calcium oxalate (CaOx) kidney stones in rats,so as to provide new ideas for the treatment of kidney stones. 【Methods】 A total of 40 rats were divided into control, SB203580, CaOx and SB203580+CaOx groups, with 10 rats in each group.Intragastric administration of a mixture of 1% ethylene glycol and 1% ammonium chloride was given to the CaOx and SB203580+CaOx groups to construct CaOx models, while intragastric administration of drinking water was given to the control and SB203580 groups.After molding, SB203580 and SB203580+CaOx groups were injected with 5 mg/kg SB203580 peritoneally once a day for 14 days, while the control and CaOx groups were injected with equal volume of normal saline.The renal mass of rats was measured and the renal coefficient was calculated; the serum levels of blood urea nitrogen (BUN) and serum creatinine (SCr) were measured with an automated biochemical analyzer; the urinary levels of neutrophil gelatinase-associated lipid carrier protein (NGAL) and kidney injury molecule-1 (KIM-1) were determined with enzyme-linked immunosorbent assay (ELISA); the crystal deposition and tissue damage in renal tissues were observed with Von Kossa staining; the apoptosis of renal tubule cells was observed with TUNEL; the expressions of autophagy markers in kidney tissues were detected with immunohistochemical staining; the molecular expressions of autophagy-endoplasmic reticulum stress related pathways in renal tissues were determined with RT-qPCR and Western blot. 【Results】 Compared with the CaOx group, the SB203580+CaOx group had increased body mass after molding (P<0.05); decreased kidney mass, kidney coefficient, BUN, SCr, NGAL and KIM-1 levels (P<0.05); alleviated pathological damage of kidney tissues; significantly reduced black crystal; down-regulated proportion of positive TUNEL cells, positive expression area of LC3B and Beclin-1, mRNA expressions of LC3B, Beclin-1, CHOP and GRP78, protein ratio of LC3-Ⅱ/LC3-Ⅰ, and protein expressions of Beclin-1, CHOP and GRP78 (P<0.05); but up-regulated mRNA and protein expressions of p62 (P<0.05). 【Conclusion】 The p38 MAPK pathway is involved in the formation of CaOx kidney stones in rats.Inhibition of this pathway can reduce the formation of kidney stones, which may be related to the regulation of autophagy and endoplasmic reticulum stress.

Objective:To explore the strategy of how to select an effective flap for reconstruction of the surgical defect in clavicular region after resection of malignant tumour and care for the aesthetic appearance of the flap donor site.Methods:A retrospective observational study was conducted. Twenty-three patients with soft tissue malignant tumour in clavicle region were treated, from March 2017 to April 2023, in the Department of Burn and Plastic Surgery of Changde Hospital, Xiangya School of Medicine, Central South University (the First People’s Hospital of Changde). The patients were 13 males and 10 females, aged 21 to 72 years old. Ten patients were of dermatofibrosarcoma protuberans, 6 of fibrosarcoma, 3 of squamous cell carcinoma of skin, 3 of undifferentiated pleomorphic sarcoma and 1 of mucinous adenocarcinoma. Nine patients had the first surgery and 14 were with tumour recurrence and had previousely received one or more surgery in other hospitals. The tumour size ranged from 2.0 cm×4.5 cm×1.0 cm to 10.0 cm×16.0 cm×3.0 cm. After radical resection, the sizes of surgical defect ranged from 9.0 cm×12.0 cm to 16.0 cm×22.0 cm. All the clavicular soft tissue malignancies had radical resection, and the secondary surgical defects were further modified to reduce the short and long dimensions of the defects. Flaps were selected according to the short dimension, depth and skin elasticity of the flap donor site. Of the 23 patients, 3 were treated with free inguinal flaps, 9 with ipsilateral pedicled latissimus dorsi flaps or thoracodorsal artery perforator flaps, 5 with free deep inferior epigastric artery perforator flap (DIEPF), 5 with free anterolateral thigh flap (ALTF) and 1 with free rectus abdominis flap. The modified defects sized 5.0 cm × 11.0 cm-12.0 cm×19.0 cm after the suture of margin and base of the defects (defects were reduced and modified). The flap sizes were 7.0 cm×13.0 cm-14.0 cm×23.0 cm. After surgery, the wound healing was observed through the visits of outpatient clinic, and telephone and WeChat interviews. According to the nature of the tumours, the patients were regularly reviewed at outpatient clinic to determine the local recurrence and metastasis of the tumour.Results:One pedicled latissimus dorsi myocutaneous flap was found with a greater tension after surgery. After partial removal of sutures and dressing changes, the secondary suture was performed 1 week later and the wound healed smoothly. A postoperative venous crisis was discovered in a free ALTF. It was monitored and re-anastomosed within 24 hours after surgery, and the flap survived and the wound healed smoothly. Otherwise, the rest of flaps achieved good blood supply and the wounds at the recipient and donor sites healed in one stage. In the postoperative follow-up, all flaps in the clavicular region were found good in appearance with no obvious swelling, and the donor sites healed well without scar contracture or dysfunction. One patient with a squamous cell carcinoma died of lung metastasis at 13 months after surgery. The rest of patients were found no tumour recurrence and had completed postoperative follow-up.Conclusion:After radical resection of malignant soft tissue tumours in the clavicular region, appropriate flaps were selected according to the size (short diameter) and depth of the modified defects, as well as the skin elasticity and relaxation of the flap donor site, hence to facilitate the direct suture of the flap donor site. It not only effectively reconstructs the surgical defect in clavicular region, but also minimises the damage to the flap donor site and achieves an aesthetic appearance at the flap donor site.

Objective:To explore the repair methods and effects of refractory wounds in patients after spinal internal fixation operation .Methods:The study was a retrospective observational study. From November 2020 to October 2023, 10 patients with refractory wounds after spinal internal fixation operation were admitted to the Department of Burns and Plastic Surgery of Changde Hospital of Xiangya School of Medicine of Central South University. They were 3 males and 7 females, aged 35 to 68 years. There were 6 cases of thoracolumbar tuberculosis, 3 cases of thoracolumbar fracture, and 1 case of recurrent sacrococcygeal chordoma with skin, soft tissue, and bone defects after radical resection. The wound areas after debridement were 6.0 cm×1.5 cm to 27.0 cm×6.5 cm. The wound repair operation was decided to perform in the primary stage or in the secondary stage according to the wound situation. Two patients with type Ⅰ wounds were treated with debridement, direct suture, and continuous irrigation and drainage with catheter after operation. Eight patients with type Ⅱ wounds were repaired with local flaps (including rotation flap with dermis-fat flap at the end), muscle flaps, or muscle flaps combined with local flaps. The flap sizes were 10.0 cm×5.0 cm to 27.0 cm×14.0 cm, and the sizes of muscle flap were 8.0 cm×5.0 cm×4.0 cm to 17.0 cm×9.5 cm×2.0 cm. The wounds in flap donor areas were sutured directly. The wound treatment methods of patients with type Ⅱ wounds were recorded. The wound healing was observed after operation. The infection and recurrence of wounds, the retention of internal fixation materials, and spinal motor function were observed during follow-up.Results:Among patients with type Ⅱ wounds, there were 3 cases applied with local flaps (including 1 case with rotation flap with dermis-fat flap at the end), 3 cases with muscle flaps (including 1 case with latissimus dorsi muscle flap and 2 cases with erector spinal muscle flaps), and 2 cases with muscle flaps (1 case with latissimus dorsi muscle flap and 1 case with erector spinal muscle flap) combined with local flaps. Only 1 case with secondary defects after radical surgery of sacrococcygeal chordoma had poor wound healing which healed after dressing change, and the wounds of the remaining 9 cases all healed well. During the follow-up of 4 to 18 months, no infection or recurrence of local wounds developed in 10 patients, the internal fixation materials were not loosening, and there was no significant limitation in spinal motor function.Conclusions:For refractory wounds after spinal internal fixation operation, according to the wound type of patients, debridement, suture, irrigation, and drainage in the primary stage, or transplantation of local flaps, muscle flaps, muscle flaps combined with local flaps are performed in the primary stage or in the secondary stage. These methods are proved to have reliable therapeutic effects, not only repairing the wounds, but also retaining the internal fixation materials.

ObjectiveTo study the effect of Xiaoyusan new formula on the articular cartilage of knee osteoarthritis (KOA) rabbits and its mechanism. MethodsA total of 42 New Zealand white rabbits aged 6 months were randomly divided into normal group, model group, ointment of Xiaoyusan group, and ointment of Xiaoyusan new formula group, with 10 rabbits in each group (the other 2 rabbits were used for model validation). Except for the normal group, the right knee joints of all rabbits in the other groups were prepared as KOA models according to the modified Hulth method. After 5 weeks of molding, the rabbits in ointment of Xiaoyusan group, ointment of Xiaoyusan New Formula group were given corresponding ointments for knee arthritis treatment, once a day, each time for 10 hours. After 2-week continuous administration and treatment, the knee joint cartilage of the four groups of rabbits was taken and the cartilage damage of each group was evaluated by Outerbridge grading method. The pathological changes of the cartilage, calcified layer and subchondral bone of the knee joint of rabbits in each group were observed by HE staining method under the light microscope, and the degree of cartilage degeneration was evaluated by Mankin's method. The expression of matrix metalloproteinase-13 (MMP-13) in the cartilage of rabbit knee joint in each group was deteced by immunohistochemistry. Results After the general observation of articular cartilage, the Outerbridge grading showed that the number of high-grade animals in ointment of Xiaoyusan group was reduced compared with the model group (P<0.05), and the number of high-grade animals in ointment of Xiaoyusan new formula group was also reduced (P<0.05) compared with ointment of Xiaoyusan group. HE staining showed that Mankin's scores of articular cartilage in the four groups ranked from high to low: model group (10.82±1.76), ointment of Xiaoyusan group (6.19±1.23), ointment of Xiaoyusan new formula group (2.64±1.18) and normal group (0.28±0.17). The difference among four groups was statistically significant (P<0.05). Immunohistochemical detection showed that the positive rates of MMP-13 expression in rabbit articular cartilage tissues in each group were (67.90±13.94)% of model group, (37.10±19.16)% of ointment of Xiaoyusan group, (13.60±3.10)% of ointment of Xiaoyusan new formula group and (3.20±2.39) % of normal group, ranking from high to low, and the difference among four groups was statistically significant (P<0.05). ConclusionXiaoyusan new formula can repair articular cartilage degeneration in KOA rabbits and decrease the expression of MMP-13 in cartilage, which may be one of the mechanisms of the treatment.

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