1.Effects and mechanisms of combined exposure to noise and microwave on hippocampal structure and function in mice
Chunxue LU ; Lei SHI ; Yue WANG ; Yanhui HAO ; Xuelong ZHAO ; Yang LI ; Hongyan ZUO ; Liqian ZHU
Journal of Environmental and Occupational Medicine 2026;43(4):419-426
Background Co-exposure to noise and microwave radiation occurs frequently. The central nervous system has been identified as a sensitive target organ for both noise and microwave exposure individually, and the underlying mechanisms remain poorly understood. The specific biological effects resulting from co-exposure to these two factors have yet to be fully elucidated. Objective To clarify the effects of co-exposure to noise and microwave on neurobehavior and hippocampal tissue structure, and to explore the underlying mechanism through the assessment of serum cytokines. Methods C57BL/6N mice were selected and randomly assigned to a blank control group, a noise group, a microwave group, and a combined noise & microwave exposure group. To establish the exposure models, the noise group was subjected to broadband noise at 100 dB for 2 h, while the microwave group received radiation at a central frequency of 9.375 GHz with an average power density of 12 mW·cm−2 and a specific absorption rate of 2.58 W·kg−1 for 15 min. Open field and tail suspension tests assessed anxiety-like emotional behaviour; novel object recognition and Y-maze tests evaluated cognitive function. Histological changes in hippocampal tissue were examined using haematoxylin and eosin (HE) staining, and Nissl staining under light microscopy. Serum cytokine levels were measured using radioimmunoassay and enzyme-linked immunosorbent assay (ELISA). Results After 3 d of exposure, the noise, microwave, and combined exposure groups showed significant reductions in exploration frequency, duration, and distance within the central zone of the open field test compared to the control group (P < 0.01); the combined exposure group exhibited increased ratios of peripheral-to-central exploration time and distance (P < 0.05). After 7 d of exposure, compared with the control group, the noise group maintained a decrease in central zone exploration time (P < 0.01), while the combined exposure group showed persistent decline across all central zone metrics (P < 0.05) and elevated peripheral-to-central ratios (P < 0.05); compared to the microwave group, the combined exposure group showed significant less time in the central zone (P < 0.05) and higher peripheral-to-central ratios (P < 0.05). Regarding behaviour and cognition, compared with the control group, the combined exposure group showed increased immobility time in the tail suspension test after 3 d of exposure (P < 0.01). At this interval, all exposure groups demonstrated reduced frequency and duration of novel object recognition (P < 0.05), with the combined exposure group showing a marked decrease in novel arm exploration time (P < 0.01). After 7 d of exposure, compared with the control group, the noise group showed reduced novel object recognition frequency (P < 0.05), and both the noise and microwave groups exhibited decreased novel arm exploration time (P < 0.05). Pathological alterations including an increased number of hyperchromatic nuclei and depleted Nissl bodies were observed in the CA3 and DG regions across all exposure groups with the most severe lesions observed in the combined exposure group. Serum levels of central nervous system-specific protein β (S-100β), glial fibrillary acidic protein (GFAP), and corticosterone (CORT) were significantly elevated in all exposure groups compared with the control group (P < 0.05). Aquaporin-4 (AQP4) levels increased in the combined exposure group (P < 0.05), while CXC chemokine ligand 10 (CXCL10) levels rose in both the noise and combined groups compared with the control group (P < 0.05). Specifically, S-100β and CXCL10 levels in the combined exposure group were higher than those in the microwave group (P < 0.05); moreover, levels of S-100β, GFAP, CORT, AQP4, and CXCL10 in the combined exposure group were significantly higher than those in the noise group (P < 0.05). Conclusion Combined exposure to noise and microwave radiation induces pathological changes in the hippocampus of mice, increases levels of serum stress hormones and neuro-specific biomarkers. These impairments are more severe than those observed following single-factor exposure. The underlaying mechanism may be related to systemic stress response, neuronal damage, astrocyte activation, and changes in blood-brain barrier permeability, leading to emotional behavioral abnormalities and cognitive decline.
2.Effect of ferroptosis-related genes on immune infiltration and prognosis in hepatocellular carcinoma
Wenjie ZHANG ; Yuxin LI ; Hongyan JIANG ; Lina MAO ; Yue MA ; Qiangsong WANG ; Yuanyuan ZHAO
International Journal of Biomedical Engineering 2025;48(4):377-391
Objective:To establish ferroptosis-related risk characteristics, to evaluate the prognostic correlation of ferroptosis-related genes in hepatocellular carcinoma, and to explore the complex relationship between hepatocellular carcinoma, ferroptosis and immune microenvironment.Methods:The bioinformatics analysis involved obtaining ferroptosis-related differentially expressed genes (DEGs) from the GeneCards database and the cancer genome atlas database. The biological functions of ferroptosis-related DEGs were analyzed using gene ontology and Kyoto encyclopedia of genes and genomes pathway enrichment. Ferroptosis-related DEGs clusters were identified using univariate Cox regression analysis and cluster analysis, etc. The correlation between ferroptosis-related DEGs clusters and tumor immune microenvironment and tumor occurrence score was evaluated using immunopanoramic analysis and tumor-related score analysis. Based on ferroptosis-related characteristics, a ferroptosis-related characteristic spectrum and nomogram were constructed using multivariate Cox regression and correlation analysis, etc. The correlation between the risk characteristics and tumor immune microenvironment, tumor occurrence score and gene mutation were evaluated using immune panoramic analysis, tumor-related score analysis and gene mutation analysis. In the experimental verification stage, the mRNA expression levels of aurora kinase A ( Aurka), acetyl-CoA carboxylase alpha ( Acaca) and arrestin domain containing 3 ( Arrdc3) in mouse primary hepatocytes and mouse hepatoma Hepa1-6 cells were verified by real-time reverse transcription-PCR (RT-qPCR). The mRNA expression levels of AURKA, ACACA and ARRDC3 in adjacent normal tissues and tumor tissues of patients with hepatocellular carcinoma were verified by RT-qPCR. A heat map was used to show the correlation between clustering and clinical parameters, and this was analyzed using a chi-square test. Significance analysis was performed using a two-sided unpaired t test. Results:A total of 35 up-regulated genes and 19 down-regulated genes were identified. These genes were mainly involved in biological processes and signaling pathways related to ferroptosis, oxidative stress and fatty acid metabolism. A total of 14 ferroptosis-related DEGs were identified to be associated with prognosis. The clusterring effect was best when hepatocellular carcinoma patients were divided into two subgroups. The survival rate of cluster 2 was lower than that of cluster 1 ( P<0.05). There was no significant difference in the tumor immune dysfunction and exclusion (TIDE) score between cluster 2 and cluster 1 ( P=0.43). Cluster 1 exhibited higher levels of immune cell infiltration, particularly CD4 + T cells ( P<0.01). The expression levels of 10 major histocompatibility complex (MHC) molecule-related genes were higher in cluster 1. The angiogenesis activity score ( P=0.048) and stemness score ( P=0.038) of cluster 2 were increased, and the expression levels of programmed death-1 ( PDCD1) and cytotoxic T lymphocyte-associated antigen-4 ( CTLA-4) in cluster 2 (5.924±0.013 and 5.475±0.042) were higher than those in cluster 1 (4.539±0.143 and 4.372±0.176) (both P<0.05). The expression levels of AURKA, glucose-6-phosphate dehydrogenease ( G6PD), ACACA, GABA type A receptor associated protein like 1 ( GABARAPL1) and ARRDC3 were correlated with the T stage, clinical stage and survival status of hepatocellular carcinoma. The survival rate of the high-risk group was lower than that of the low-risk group with time ( P<0.01). The area under the curve of the risk characteristics at 1, 3 and 5 years was 0.797, 0.717 and 0.639, respectively. The actual survival time 1, 3, and 5 years was highly consistent with the corresponding predicted survival time. The levels of memory B cell infiltration, angiogenesis activity score and cell stemness score, programmed death-ligand 1, CTLA-4, hepatitis A virus cell receptor 2, lymphocyte activation gene 3 and PDCD1 gene expression (0.013 8±0.036 0, 0.884±0.212, 0.387±0.135, 6.273±0.228, 5.847±0.331, 8.179±0.259, 6.859±0.263 and 5.142±0.326) in the high-risk group were higher than those in the low-risk group (0.001 5±0.021 0, 0.874±0.132, 0.298±0.125, 5.866±0.132, 3.742±0.237, 7.236±0.321, 6.324±0.242 and 4.513±0.211) ( P<0.05, 0.01). The expression levels of MHC molecule-related genes in the high-risk group were also higher than those in the low-risk group ( P<0.05, 0.01), while the infiltration levels of resting mast cells, activated natural killer cells, and resting natural killer cells (0.043 2±0.135 0, 0.032 1±0.143 0 and 0.016 3±0.001 9) and the TIDE score (0.072 0±0.018 0) in the high-risk group were lower than those in the low-risk group (0.054 9±0.023 0, 0.042 7±0.017 0, 0.024 6±0.021 2 and 0.094 0±0.013 5) ( P<0.05, 0.01). The top five genes with the highest mutation frequency in the high-risk group were tumor protein P53 ( TP53, 43%), titin ( TTN, 21%), catenin beta 1 ( CTNNB1, 20%), mucin 16 ( MUC16, 18%) and piccolo presynaptic cytomatrix protein ( PCLO, 11%). The top five genes with the highest mutation frequency in the low-risk group were CTNNB1 (30%), TTN (24%), albumin ( ALB, 16%), MUC16 (15%) and PCLO (11%). The cube protein and PCLO showed the co-occurrence of gene mutations in the high-risk group, while MUC16 and axis 1 protein showed the co-occurrence of gene mutations in the low-risk group. There was no significant difference in tumor mutation burden (TMB) between the high-risk group (1.374±0.026) and the low-risk group (1.303±0.081) ( P=0.073). There was no significant difference in survival time between the high-TMB group (2.3 years) and the low-TMB group (3.8 years) ( P=0.293). The mutation rates of AURKA, G6PD, ACACA, GABARAPL1 and ARRDC3 genes (2.0%, 2.0%, 4.0%, 0.3% and 0.6%) were relatively low. The relative expression levels of Aurka, Acaca and Arrdc3 mRNA in Hepa1-6 cells (13.331±0.000, 6.619±0.000 and 1.209±0.002) were higher than those in mouse primary hepatocytes (1.000±0.000, 1.000±0.000 and 1.000±0.000) (all P<0.01). The relative expression levels of AURKA, ACACA and ARRDC3 mRNA in tumor tissues of patients with hepatocellular carcinoma (2.102±0.365, 2.476±0.351 and 11.460±9.189) were higher than those in adjacent normal tissues of patients with hepatocellular carcinoma (1.122±0.648, 0.831±0.935 and 0.852±0.171) ( P<0.05, 0.01). Conclusions:This study constructed a prognostic signature comprising five ferroptosis-related genes ( AURKA, G6PD, ACACA, GABARAPL1, and ARRDC3) that is highly correlated with clinical hepatocellular carcinoma data. This study highlights the significance of ferroptosis-related genes as prognostic markers for hepatocellular carcinoma and provides insights into the complex relationship between hepatocellular carcinoma, ferroptosis, and the immune microenvironment.
3.Therapeutic effects of Pueraria lobata (Willd.) Ohwi root and Hovenia dulcis Thunb. extracts on alcoholic liver disease: Network pharmacology and experimental validation
Zhendong Chen ; Yu Yue ; Hongyan An ; Haisu Yan ; Hyeok-Joo Park ; Pei Lin
Journal of Traditional Chinese Medical Sciences 2025;2025(1):100-111
Objective:
To investigate the protective effects of the combined concentrated liquid extract of Pueraria lobata (Willd.) Ohwi root (P. lobata, Ge Gen) and Hovenia dulcis Thunb. (H. dulcis, Zhi Ju Zi) against ethanol-induced liver damage in vitro, using a human hepatoma cell line G2 (HepG2) cell model.
Methods:
HepG2 cells were cultured in medium containing 4% ethanol to establish a model of alcoholic liver damage. The cells were then treated with the combined extract obtained via cryogenic extraction. Biochemical assays and Western blot analyses were performed to assess the levels of oxidative stress markers, antioxidant enzymes, and inflammatory cytokines. In addition, activation of the phosphoinositide 3-kinase/protein kinase B (PI3K/AKT) pathway was examined to elucidate the mechanisms underlying the effects of the extract.
Results:
Treatment with the extract contributed to a significant reduction in the release of nitric oxide and reactive oxygen species in the ethanol-treated HepG2 cells; promoted the elevated expression of superoxide dismutase, catalase, and glutathione, indicating enhanced antioxidant defenses; and showed strong free radical-scavenging activity against 1,1-diphenyl-2-picrylhydrazyl radicals. In addition, by activating the PI3K/AKT pathway, treatment promoted increases in the expression of nuclear factor erythroid 2-related factor 2 and its downstream targets, subsequently inhibiting apoptosis. Moreover. inflammatory responses were mitigated, as indicated by reductions in the expression of tumor necrosis factor-alpha and interleukin-6, and we detected reduction in the levels of alanine aminotransferase and aspartate aminotransferase, thereby indicating hepatoprotective effects.
Conclusion
The combined P. lobata root and H. dulcis extract was established to have notable antioxidative and anti-inflammatory properties, effectively alleviating ethanol-induced liver damage in vitro. These findings highlight the potential applicability of this extract as a candidate for treating alcoholic liver disease.
4.Pitavastatin-loaded procyanidins self-assembled nanoparticles alleviate advanced atherosclerosis via modulating macrophage efferocytosis and cholesterol efflux.
Yizhou WU ; Hongyan ZHOU ; Hao LIU ; Jiayao HU ; Yue SUN ; Wei YAN ; Chunyi TONG ; Ying KONG ; Bin LIU
Acta Pharmaceutica Sinica B 2025;15(6):3305-3320
Advanced atherosclerosis is the major global cause of death, as featured by the aggregation of apoptotic cells (ACs) in necrotic cores. The defective efferocytosis and dysfunctional cholesterol efflux of macrophages are the main reasons for forming necrotic cores in advanced atherosclerosis. In this study, we constructed self-assembled procyanidins (PC) NPs for loading pitavastatin (Pita). The designed HA@PC@Pita NPs with hyaluronic acid (HA) modification combined the advantages of efferocytosis restoration of Pita and cholesterol efflux enhancement of PC. In vitro assay indicated that HA@PC@Pita NPs could induce M1/M2 repolarization and upregulate ERK5/Mertk expression to restore efferocytosis of macrophages. Simultaneously, HA@PC@Pita NPs notably promoted cholesterol efflux by promoting macrophage lipophagy, a selective autophagy of lipid droplets. In vivo study showed that HA@PC@Pita NPs cleared necrotic core and enhanced plaque stability in the ApoE -/- mice model with advanced atherosclerosis. Taken together, this study demonstrated the potential of HA@PC@Pita NPs for the treatment of advanced atherosclerosis.
5.Research methods of vaccination coverage and their application in evaluating vaccine protective effectiveness
Weiwei HAN ; Siyue JIA ; Hongyan LIU ; Yue LIU ; Fengcai ZHU ; Jingxin LI
Chinese Journal of Epidemiology 2025;46(9):1673-1679
The impact of vaccines on public health and their effectiveness in controlling infectious diseases partly depends on their coverage rate, which refers to the proportion of individuals vaccinated within a specific population. Vaccination coverage is foundational data for vaccine immunization programs, a key parameter for evaluating and monitoring the implementation of vaccination plans, and an important data point in real-world post-market studies of vaccines. Additionally, research on vaccination coverage is becoming increasingly prevalent in vaccine evaluation, primarily used to establish the risk of disease incidence in populations with different vaccination coverage rates in order to assess the protective effectiveness of vaccines. This paper reviews the research methods used to assess vaccine coverage both domestically and internationally, as well as their applications in evaluating vaccine effectiveness. It also analyzes and compares the advantages and disadvantages of different research methods for measuring vaccination coverage and discusses the significance of monitoring and improving vaccine coverage rates. The goal is to promote research and application of vaccination coverage rates in China, providing a scientific basis for post-market vaccine studies and for local administrative departments to formulate immunization policies.
6.Screening and biological characteristics of bacteriophage HN_Aba_01 against multidrug-resistant Acinetobacter baumannii
Hanwang ZHOU ; Lin CONG ; Mei YU ; Huihui KUANG ; Yue ZHANG ; Hongyan HU
Chinese Journal of Nosocomiology 2025;35(20):3089-3094
OBJECTIVE To analyze the biological characteristics and genomic features of highly lytic bacteriopha-ges isolated from sewage in tropical hospitals and provide references for the hospital-associated infection prevention and control of multidrug-resistant Acinetobacter baumannii(MDR-Ab).METHODS With MDR-Ab as the host bacterium,bacteriophages were isolated from sewage.Transmission electron microscopy was employed to observe their morphology,and determine the optimal multiplicity of infection(MOI),one-step growth curve and environ-mental stability.Whole-genome sequencing and bioinformatics analysis were conducted to annotate functional genes and construct a phylogenetic tree.RESULTS A virulent bacteriophage,HN_Aba_01,was isolated.Elec-tron microscopy revealed that it belonged to the Myoviridae family,with a head diameter of 50 nm and a tail length of 90 nm.This bacteriophage exhibited strong lytic activity,with an optimal MOI of 0.000 000 1,a latent period of 5 minutes and a lysis yield of 15 PFU/cell.It remained stable at temperatures ranging from 4 ℃ to 60 ℃and pH values from 3 to 10.Genomic analysis identified 85 ORFs,including lyase,perforin and depolymerase genes.It shared 98.12%identity with the bacteriophage AbP2 genome(reference genome)and was classified into the Obolenskvirus genus.CONCLUSIONS The bacteriophage isolated from tropical hospital sewage,with high lyt-ic activity and good environmental adaptability,can be used for the hospital-associated infection prevention and control of MDR-Ab.
7.Exploring Mechanism of Hei Xiaoyaosan Regulating PI3K/Akt Pathway to Improve Learning and Memory Ability of Insomnia Rats with Liver Depression Syndrome Based on Transcriptomics
Jiamin LIU ; Yale WANG ; Hai HUANG ; Yue LI ; Xin FAN ; Pengpeng LIANG ; Shizhao ZHANG ; Mei YAN ; Guiyun LI ; Hongyan WU
Chinese Journal of Experimental Traditional Medical Formulae 2025;31(16):114-125
ObjectiveBased on transcriptomics, to explore the mechanism of Hei Xiaoyaosan regulating the phosphatidylinositol 3-kinase/protein kinase B (PI3K/Akt) signaling pathway to improve the learning and memory ability of insomnia rats with liver depression syndrome. MethodsSixty 8-week-old male SD rats were randomly divided into the blank group, model group, eszopiclone group (0.09 mg·kg-1), and low, medium, and high dose groups of Hei Xiaoyaosan (3.82, 7.65, 15.30 g·kg-1), with ten rats in each group. Except for the blank group, the other groups were induced insomnia rat model with liver depression by chronic restraint, tail clamping stimulation and intraperitoneal injection of p-chlorophenylalanine (PCPA). Each treatment group received intragastric administration according to the specified dosage, once a day for 14 consecutive days. The pentobarbital sodium cooperative sleep test, open field test, and Morris water maze test were used to test the sleep quality, depressive-like behavior, and learning and memory abilities of rats. Additionally, enzyme-linked immunosorbent assay (ELISA) was used to detect the contents of 5-hydroxytryptamine (5-HT), γ-aminobutyric acid (GABA), brain-derived neurotrophic factor (BDNF), glial cell line-derived neurotrophic factor (GDNF) and nitric oxide (NO) in hippocampus. Hematoxylin-eosin (HE) staining was performed to observe pathological changes of the hippocampal tissue, while terminal deoxynucleotidyl transferase deoxyuridine triphosphate (dUTP) nick end labeling (TUNEL) was used to evaluate apoptosis of hippocampal neurons. Transcriptomic sequencing technology was employed to identify differentially expressed genes in hippocampus between the model group and the blank group, as well as between the medium-dose group of Hei Xiaoyaosan and the model group. Gene Ontology (GO) and Kyoto Encyclopedia of Genes and Genomes (KEGG) enrichment analysis were performed on the intersecting genes. Subsequently, the enriched key genes and signaling pathways were analyzed and verified. Real-time fluorescence quantitative polymerase chain reaction (Real-time PCR) was utilized to assess the mRNA expression levels of phosphatase and tensin homolog (PTEN), B-cell lymphoma-2 (Bcl-2)-like protein 11 (BCL2L11), and mitogen-activated protein kinase 1 (MAPK1) in hippocampus, and Western blot was employed to evaluate the protein expressions of PI3K, phosphorylation (p)-PI3K, Akt, p-Akt, Bcl-2, Bcl-2-associated X protein (Bax), and cleaved Caspase-3 in the same tissue. ResultsCompared with the blank group, the model group exhibited a reduction in body weight, an increase in sleep latency, and a decrease in sleep duration (P<0.01). Additionally, rats showed obvious depression-like behavior, and their learning and memory abilities decreased. Furthermore, the contents of 5-HT, GABA, NO, BDNF and GDNF in hippocampus decreased (P<0.01). Histological examination revealed a disorganized cell arrangement in the CA1 region of the hippocampus, characterized by irregular cell shapes, a reduced cell count, deeply stained and pyknotic nuclei, increased vacuolar degeneration, and an elevated apoptosis rate (P<0.01). Compared with the model group, the body weight of the high and medium dose groups of Hei Xiaoyaosan increased, the sleep latency shortened and the sleep time prolonged (P<0.05, P<0.01). Additionally, depression-like behavior and learning and memory abilities of rats were significantly improved, the levels of 5-HT, GABA, NO, BDNF and GDNF in the hippocampus increased (P<0.05, P<0.01). These interventions also ameliorated pathological damage in the hippocampal CA1 area and reduced the apoptosis of hippocampal neurons (P<0.01). Transcriptomic sequencing results indicated that Hei Xiaoyaosan might exert a therapeutic effect by regulating PI3K/Akt pathway through key mRNAs such as PTEN, BCL2L11, and MAPK1. The roles of these key mRNAs and proteins within PI3K/Akt pathway were further validated. In comparison to the blank group, the expression levels of PTEN, BCL2L11 and MAPK1 mRNA in the hippocampus of rats in the model group were increased (P<0.01), while the protein expression levels of p-PI3K, p-Akt and Bcl-2 were decreased (P<0.01), and the protein expression levels of PTEN, Bax and cleaved Caspase-3 were increased (P<0.01). Compared with the model group, the high-dose and medium-dose groups of Hei Xiaoyaosan could down-regulate the expressions of PTEN, BCL2L11 and MAPK1 mRNAs (P<0.01), up-regulate the expressions of p-PI3K, p-Akt and Bcl-2 proteins (P<0.01), and down-regulate the protein expressions of PTEN, Bax and cleaved Caspase-3 (P<0.05, P<0.01). ConclusionHei Xiaoyaosan may regulate PI3K/Akt signaling pathway by down-regulating expressions of key genes such as PTEN, BCL2L11 and MAPK1, and thus improve the learning and memory abilities of insomnia rats with liver depression syndrome.
8.A journey map study of disease management in young and middle-aged liver transplant recipients
Yue QIAO ; Qingwei LIU ; Hui LIN ; Kai ZHU ; Hui LI ; Yanan DU ; Hongyan ZHANG
Chinese Journal of Nursing 2025;60(15):1850-1857
Objective Utilizing patient journey mapping to decipher disease management behaviors,barriers,and needs in young and middle-aged liver transplant recipients,providing implications for self-management optimization and quality of life improvement.Methods Using purposive sampling,12 young and middle-aged liver transplant patients who attended outpatient clinics or were hospitalized in liver transplant center of a tertiary hospital in Qingdao were selected for semi-structured interviews from September to November 2024.Thematic extraction and analysis were performed using Colaizzi's 7-step analysis,ultimately resulting in the development of a patient journey map.Results The journey stages were divided into transplantation decision-making period,transplantation waiting period,perioperative period,and post-discharge management period,and the journey key elements were designed as behaviors,barriers,and needs.A total of 25 themes were extracted,including behaviors(such as referrals to higher-level hospitals,verification of treatment options),barriers(such as lack of decision-making autonomy,health information-seeking barriers),and needs(such as shared decision-making,financial assistance).Ultimately,resulting in a map of the disease management journey for young and middle-aged liver transplant recipients.Conclusion The behaviors,barriers,and needs in disease management among young and middle-aged liver transplant recipients demonstrate distinct phase-specific patterns.Healthcare providers should deliver precise and dynamic interventions tailored to each clinical phase,aiming to foster optimal self-management behaviors,address phase-specific banriers,and meet evolving patient needs throughout the transplant continuum.
9.Genomics of small colony variants of clinical Staphylococcus aureus isolates
Huihui KUANG ; Lin CONG ; Hongyan HU ; Song LI ; Yue LIU
Chinese Journal of Nosocomiology 2025;35(9):1287-1292
OBJECTIVE To explore the molecular characteristics of small colony variants(SCVs)of Staphylococcus aureus isolates so as to provide theoretical bases for clinical control of the persistent and recurrent infections in-duced by the SCVs.METHODS The clinical blood specimens that were collected from the First Affiliated Hospital of Traditional Chinese Medicine University of Guangzhou were cultured to acquire 1 strain of SCV S.aureus S2.The colonial morphology,growth rate,catalase,plasma-coagulase,production capability of biofilm and antimi-crobial susceptibility of the strain SCVs were observed,the growth curve and autolysis curve were drawn,the whole genome sequencing was performed for the S2,the phylogenetic evolution of the genome and the single nu-cleotide polymorphism(SNP)were analyzed.RESULTS The S2 was identified as S.aureus,with the catalase and plasma-coagulase tested positive.The strain was resistant to various types of antibiotics,including macrolides like erythromycin and azithromycin,fluroquinolones such as levofloxacin and ciprofloxacin,and penicillin.The forma-tion of pigment was reduced,the formation of hemolytic rings was low;the growth rate of the strain was slower than that of ATCC 25923(quality control strain)and ZC1(the normal control strain),the autolytic activity of the strain was higher than that of the ATCC 25923 and ZC1,and the biofilm production of the strain was remarkably less than that of the ATCC 29213(P<0.05).The whole genome sequencing demonstrated that the molecular typ-ing of the S2 was ST239-t030 clone,which harbored a variety of drug resistance genes and virulence genes,and the menB gene had missense mutation.CONCLUSION The formation of SCVs may be associated with the inhibited synthesis of menadione caused by the missense mutation of menB gene.
10.Screening and biological characteristics of bacteriophage HN_Aba_01 against multidrug-resistant Acinetobacter baumannii
Hanwang ZHOU ; Lin CONG ; Mei YU ; Huihui KUANG ; Yue ZHANG ; Hongyan HU
Chinese Journal of Nosocomiology 2025;35(20):3089-3094
OBJECTIVE To analyze the biological characteristics and genomic features of highly lytic bacteriopha-ges isolated from sewage in tropical hospitals and provide references for the hospital-associated infection prevention and control of multidrug-resistant Acinetobacter baumannii(MDR-Ab).METHODS With MDR-Ab as the host bacterium,bacteriophages were isolated from sewage.Transmission electron microscopy was employed to observe their morphology,and determine the optimal multiplicity of infection(MOI),one-step growth curve and environ-mental stability.Whole-genome sequencing and bioinformatics analysis were conducted to annotate functional genes and construct a phylogenetic tree.RESULTS A virulent bacteriophage,HN_Aba_01,was isolated.Elec-tron microscopy revealed that it belonged to the Myoviridae family,with a head diameter of 50 nm and a tail length of 90 nm.This bacteriophage exhibited strong lytic activity,with an optimal MOI of 0.000 000 1,a latent period of 5 minutes and a lysis yield of 15 PFU/cell.It remained stable at temperatures ranging from 4 ℃ to 60 ℃and pH values from 3 to 10.Genomic analysis identified 85 ORFs,including lyase,perforin and depolymerase genes.It shared 98.12%identity with the bacteriophage AbP2 genome(reference genome)and was classified into the Obolenskvirus genus.CONCLUSIONS The bacteriophage isolated from tropical hospital sewage,with high lyt-ic activity and good environmental adaptability,can be used for the hospital-associated infection prevention and control of MDR-Ab.


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