الملخص
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.
الموضوعات
Humans , Water , Bacteria/genetics , Seawater/microbiology , Escherichia coli , Enterococcus , Klebsiella pneumoniae , Chinaالملخص
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.
الموضوعات
Humans , Water , Bacteria/genetics , Seawater/microbiology , Escherichia coli , Enterococcus , Klebsiella pneumoniae , Chinaالملخص
The purpose of this study was to explore the differences in interhemispheric functional connectivity in patients with Alzheimer's disease (AD) and amnestic mild cognitive impairment (aMCI) based on a triple network model consisting of the default mode network (DMN), salience network (SN), and executive control network (ECN). The technique of voxel-mirrored homotopic connectivity (VMHC) analysis was applied to explore the aberrant connectivity of all patients. The results showed that: (1) the statistically significant connections of interhemispheric brain regions included DMN-related brain regions (i.e. precuneus, calcarine, fusiform, cuneus, lingual gyrus, temporal inferior gyrus, and hippocampus), SN-related brain regions (i.e. frontoinsular cortex), and ECN-related brain regions (i.e. frontal middle gyrus and frontal inferior); (2) the precuneus and frontal middle gyrus in the AD group exhibited lower VMHC values than those in the aMCI and healthy control (HC) groups, but no significant difference was observed between the aMCI and HC groups; and (3) significant correlations were found between peak VMHC results from the precuneus and Mini Mental State Examination (MMSE) and Montreal Cognitive Scale (MOCA) scores and their factor scores in the AD, aMCI, and AD plus aMCI groups, and between the results from the frontal middle gyrus and MOCA factor scores in the aMCI group. These findings indicated that impaired interhemispheric functional connectivity was observed in AD and could be a sensitive neuroimaging biomarker for AD. More specifically, the DMN was inhibited, while the SN and ECN were excited. VMHC results were correlated with MMSE and MOCA scores, highlighting that VMHC could be a sensitive neuroimaging biomarker for AD and the progression from aMCI to AD.
الموضوعات
Aged , Aged, 80 and over , Female , Humans , Male , Middle Aged , Alzheimer Disease/physiopathology , Brain/diagnostic imaging , Brain Mapping , Cognitive Dysfunction/physiopathology , Magnetic Resonance Imaging , Memory , Models, Neurological , Nerve Netالملخص
Objective To investigate the effects of different concentrations of crocin on receptor activator of nuclear factor kappa B ligand (RANKL)-induced osteoclastogenesis using the monocyte-macrophage cell line RAW264.7. Methods The monocyte-macrophage cell line RAW264.7 was cultured routinely.After treatment with 0,6.25,12.5,25, 50,100,200 and 400 μmol/L crocin,cell counting kit-8(CCK-8)assay was used to analyze the viability of RAW264.7 cells to screen out the appropriate experimental concentration. RAW264.7 cells were induced by RANKL (100 ng/L) to form osteoclasts. After treated with 0, 12.5, 50 and 100 μmol/L crocin respectively, the number of osteolasts was counted by tatrate resistant acid phosphatasec (TRAP) staining. Real-time PCR was used to detect the mRNA expression levels of calcitonin receptor(CTR),nuclear factor of active T cells 1(NFATC1),C-fos and TRAP.Results No significant effects of crocin (within 0-100 μmol/L) were found on the viability of RAW264.7 cells (P>0.05). However, When crocin concentration was over 100 μmol/L,the cell proliferation was decreased,and which showed a significant inhibitory effect on proliferation (P<0.05). Thus, 0-100 μmol/L crocin was selected as the experiment concentration. The amount of differentiated osteolasts and the expression levels of CTR,NFATC1,C-fos and TRAP mRNA were decreased significantly with the increased concentrations of crocin(P<0.05).Conclusion At a certain concentration(0-100 μmol/L),the higher levels of crocin could inhibit RANKL-induced osteoclastogenesis.
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Objective To investigate the clinical distribution and antimicrobial resistance of carbapenem-resistant Enterobacteriaceae (CRE) in Dongguan.Methods CRE isolated from hospitalized patients in 22 secondary and above medical institutions which participated in bacterial monitoring in Dongguan between January 2015 and June 2016 were retrospectively analyzed,antimicrobial resistance was analyzed by WHONET 5.6 software.Results A total of 71 CRE isolates were detected,with a isolation rate of 0.34% (71/20 713).53 strains(74.65%) of CRE were isolated from patients aged 15-60 years old;46 (64.79 %) were from male patients;CRE were mainly isolated from patients in intensive care unit(36 strains,50.70 %);the main specimen was sputum(34 strains,47.89 %),followed by urine (11 strians,15.49 %) and wound secretion(6 strains,8.45 %);the main infection type was healthcare associated infection (64 strains,90.14 %);CRE were mainly distributed in tertiary hospitals(56 strains,78.87 %),the isolation rate of CRE in tertiary and secondary hospitals were 0.41 %(56/13 677)and 0.21%(15/7 036) respectively.71 strains of CRE were all resistant to imipenem,resistance rate to meropenem was 81.12%,only amikacin and tobramycin had drug resistance rates of <40% (21.38% and 38.79% respectively),resistance rate to trime thoprim/sulfamethoxazole was 48.23 %,while resistance rates to fluoroquinolones,third-generation cephalosporins,and enzyme inhibitors were all>60.Conclusion The isolation rate of CRE in Dongguan is lower than that of the whole nation and the other provinces,effective prevention and control measures should be taken according to the key population and departments that isolated CRE,antimicrobial use should be rational.