Bacterial resistance has always been a challenge in the field of antibacterials research. As one of the most problematic pathogens causing nosocomial infections, Acinetobacter baumannii (A. baumannii) was a severe threaten to public health. In recent years, as the rate of multidrug-resistant, extensively drug-resistant, and even pan drug-resistant A. baumannii has been increasing, there is an urgent need to develop new strategies to combat this pathogen. Iron is an essential element for the survival and the infection process of A. baumannii. Bacteria have developed a series of iron uptake strategies to survive in conditions of the host iron starvation, including the secretion of siderophore for iron chelation, the uptake of ferroheme, and the transport of ferrous by Feo system. Developing antibacterial strategies to inhibit the iron uptake is an effective way to deal with A. baumannii infection. This article will review the mechanisms of iron uptake by A. baumannii and the antimicrobial strategies developed based on them.

Objective This study aimed to investigate the potential relationship between urinary metals copper (Cu), arsenic (As), strontium (Sr), barium (Ba), iron (Fe), lead (Pb) and manganese (Mn) and grip strength. Methods We used linear regression models, quantile g-computation and Bayesian kernel machine regression (BKMR) to assess the relationship between metals and grip strength.Results In the multimetal linear regression, Cu (β=-2.119), As (β=-1.318), Sr (β=-2.480), Ba (β=0.781), Fe (β= 1.130) and Mn (β=-0.404) were significantly correlated with grip strength (P < 0.05). The results of the quantile g-computation showed that the risk of occurrence of grip strength reduction was -1.007 (95％ confidence interval:-1.362, -0.652; P < 0.001) when each quartile of the mixture of the seven metals was increased. Bayesian kernel function regression model analysis showed that mixtures of the seven metals had a negative overall effect on grip strength, with Cu, As and Sr being negatively associated with grip strength levels. In the total population, potential interactions were observed between As and Mn and between Cu and Mn (Pinteractions of 0.003 and 0.018, respectively).Conclusion In summary, this study suggests that combined exposure to metal mixtures is negatively associated with grip strength. Cu, Sr and As were negatively correlated with grip strength levels, and there were potential interactions between As and Mn and between Cu and Mn.

Objective To investigate the influences of Lycium barbarum polysaccharide on apoptosis of corneal epithelial cells induced by hypertonicity through regulating adenosine monophosphate activated protein kinase(AMPK)/uncoordinated 51-like kinase 1(ULK1)autophagy pathway.Methods The ophthalmoxerosis cell model was established by osmotic pressure of 500 mOsm·L-1 on corneal epithelial cells.They were divided into model group,positive control group(0.3％sodium hyaluronate eye drops),inhibitor group(1 mg·mL-1 Lycium barbarum polysaccharide+10 μmol·L-1compound C),experimental-L,-H groups(0.5,1.0 mg·mL 1 Lycium barbarum polysaccharide),and normal cultured CRL-11135 cells were taken as blank group(no treatment was performed).Cell apoptosis was detected by flow cytometry.Autophagy was detected by MDC staining.Western blot was used to detect the expressions of p-AMPK/AMPK and p-ULK1/ULK1.Results The apoptosis rates of experimental-L,experimental-H,positive control,inhibitor,model and blank groups were(26.47±2.13)％,(13.68±2.21)％,(12.54±2.16)％,(18.73±2.12)％,(37.56±3.25)％and(6.35±2.14)％;the relative contents of autophagosomes were(59.63±8.14)％,(89.89±9.04)％,(90.31±9.13)％,(62.75±7.26)％,(43.11±6.45)％and(100.00±0.00)％;p-AMPK/AMPK were 0.45±0.07,0.64±0.08,0.66±0.06,0.53±0.04,0.34±0.05 and 0.87±0.06;p-ULKl/ULKl were 0.54±0.06,0.75±0.05,0.77±0.03,0.65±0.04,0.46±0.04 and 0.92±0.08,respectively.The above indexes in experimental-L,-H groups and positive control group were significantly different from those in model group(all P＜0.05);the above indexes in inhibitor group were significantly different from those in experimental-H group(all P＜0.05).Conclusion Lycium barbarum polysaccharide can inhibit the apoptosis of corneal epithelial cells induced by hypertonicity by activating the AMPK/ULK1 autophagy pathway.

Objective To investigate the effects of raddeanin A(RA)on the proliferation and apoptosis of HCT116 cells and on the β-catenin/c-Myc pathway.Methods Human colon cancer HCT116 cells were divided into four groups:Control group,experimental-L group,experimental-M group and experimental-H group.Experimental-L,experimental-M,experimental-H groups were treated with 5,10 and 20 μmol·L-1raddeanin A,and the control group was given the same amount of normal saline,respectively.The inhibitory effect of RA on the proliferation of HCT116 cells of colon cancer was detected by cell counting kit-8(CCK-8)method.Cell nucleus morphology change was observed with the fluorescence;the apoptosis rate was detected by flow cytometry;and the expression of related proteins of β-catenin/c-Myc signaling pathway was detected by western blot.Results After 48 h,the cell inhibitory rates of the control group,experimental-L,experimental-M,experimental-H groups were 0,(19.15±0.65)％,(35.11±0.40)％and(49.93±1.13)％,respectively;the cell apoptosis rates were(0.16±0.18)％,(9.26±0.42)％,(17.87±2.54)％and(38.10±2.70)％,respectively;the protein expression levels of β-catenin were 0.74±0.03,0.69±0.01,0.33±0.02 and 0.16±0.04,respectively;the protein expression levels of c-Myc were 0.89±0.01,0.54±0.03,0.29±0.03 and 0.13±0.04,respectively;the protein expression levels of Cyclin D1 were 0.84±0.04,0.66±0.01,0.48±0.06 and 0.21±0.03,respectively;the expression levels of Cleaved-Caspase3 protein were 0.19±0.03,0.26±0.04,0.45±0.04 and 0.78±0.01,respectively.The above indicators in the experimental-L,experimental-M,experimental-H groups showed statistically significant differences compared to those of control group(all P＜0.05).Conclusion RA can inhibit the proliferation of HCT116 cells and induce apoptosis,which may be related to the inhibition of β-catenin/c-Myc signaling pathway.

Objective To investigate the effects of acetylshikonin on proliferation,invasion and migration of oxaliplatin-resistant human colon cancer HCT116 cells(HCT116/L-OHP).Methods HCT116/L-OHP cells were divided into blank group,control group,experimental-L group,experimental-M group and experimental-H group.The control group was treated with 10 μmol·L-1 oxaliplatin.The experimental-L,experimental-M,experimental-H groups were treated with 1.25,2.50 and 5.00 μmol·L-1 acetylshikin and 10 μmol·L-1 oxaliplatin,respectively.The blank group was given routine culture.The changes of HCT116/L-OHP cell proliferation were detected by cell counting kit-8(CCK-8)method;flow cytometry was used to evaluate the apoptosis of cells;Transwell assay was used to detect the changes of cell migration and invasion ability;Western blot was used to detect the expressions of P-glycoprotein(P-gp),matrix metallo-proteinases 2(MMP2),nuclear factor kappa-B(NF-κB)/and hypoxia induced factor-1 α(HIF-1α)proteins.Results The cell inhibition rates of the blank group,control group and experimental-L,-M,-H groups were 0,(8.27±0.01)％,(10.53±0.02)％,(34.17±0.01)％and(48.47±0.05)％;cell apoptosis rates were(0.13±0.02)％,(1.37±1.04)％,(9.73±0.87)％,(26.71±4.26)％and(40.75±4.70)％;invading cells were 130.70±9.81,127.10±9.21,71.83±3.57,28.83±1.87 and 19.63±6.11;the number of migration cells was 150.50±10.17,148.40±8.13,94.58±4.09,63.98±5.09 and 31.85±5.50;the relative expression levels of P-gp protein were 0.91±0.01,0.89±0.02,0.75±0.04,0.61±0.07 and 0.25±0.03;the relative expression levels of MMP2 protein were 1.24±0.01,1.22±0.02,0.96±0.01,0.53±0.01 and 0.16±0.02;the relative expression levels of NF-κB-p65 were 1.12±0.12,1.07±0.01,0.78±0.01,0.64±0.02 and 0.31±0.03;the relative expression levels of HIF-1 α were 0.65±0.04,0.52±0.03,0.41±0.02,0.35±0.03 and 0.09±0.01,respectively.The above indicators in the experimental-L,-M,-H groups showed statistically significant differences compared to those of blank group(all P＜0.05).Conclusion Acetylshikonin combined with oxaliplatin can significantly inhibit the proliferation,invasion and migration of HCT116/L-OHP cells,and induce cell apoptosis,which may be related to the inhibition of P-gp and MMP2 expression and the activation of NF-κB/HIF-1 α signal.

This study aims to investigate the function of lmo2363 gene in stress resistance of Liste-ria monocytogenes strain LM83-1.In this study,the lmo2363 gene deletion strain and complement-ation strain of Listeria monocytogenes were constructed using overlapping extended PCR and ho-mologous recombination techniques,and the growth ability,stress survival rate and biofilm forma-tion ability of wild,deletion strain and complementation strain were compared under different stress environments.lmo2363 gene deletion strain and complementation strain of Listeria monocy-togenes were successfully constructed in this experiment.The growth curves showed that the growth capacity of the deletion strain was weaker than the wild strain LM83-1 under 4 ℃,7％NaCl,10％NaCl,3.5％ethanol,4.0％ethanol and pH5 stress(P＜0.001).The results of stress survival test showed that the survival rate of the deletion strain was significantly lower than the wild strain after 1 h treatment with pH3 and 10 mmol/L H2 O2 stress(P＜0.010).The biofilm forming ability of the deletion strain was decreased compared with that of the wild strain(P＜0.050).This study confirmed that lmo2363 gene mediated the adaptation of LM to low temperature,high osmotic pressure,ethanol and acid stress environment and affected the formation of LM bio-film.This study laid a foundation for further exploring the function of lmo2363 gene in the stress resistance process of Listeria monocytogenes.

Objective To investigate the clinical characteristics and prognosis of pneumococcal meningitis(PM),and drug sensitivity of Streptococcus pneumoniae(SP)isolates in Chinese children.Methods A retrospective analysis was conducted on clinical information,laboratory data,and microbiological data of 160 hospitalized children under 15 years old with PM from January 2019 to December 2020 in 33 tertiary hospitals across the country.Results Among the 160 children with PM,there were 103 males and 57 females.The age ranged from 15 days to 15 years,with 109 cases(68.1% )aged 3 months to under 3 years.SP strains were isolated from 95 cases(59.4% )in cerebrospinal fluid cultures and from 57 cases(35.6% )in blood cultures.The positive rates of SP detection by cerebrospinal fluid metagenomic next-generation sequencing and cerebrospinal fluid SP antigen testing were 40% (35/87)and 27% (21/78),respectively.Fifty-five cases(34.4% )had one or more risk factors for purulent meningitis,113 cases(70.6% )had one or more extra-cranial infectious foci,and 18 cases(11.3% )had underlying diseases.The most common clinical symptoms were fever(147 cases,91.9% ),followed by lethargy(98 cases,61.3% )and vomiting(61 cases,38.1% ).Sixty-nine cases(43.1% )experienced intracranial complications during hospitalization,with subdural effusion and/or empyema being the most common complication[43 cases(26.9% )],followed by hydrocephalus in 24 cases(15.0% ),brain abscess in 23 cases(14.4% ),and cerebral hemorrhage in 8 cases(5.0% ).Subdural effusion and/or empyema and hydrocephalus mainly occurred in children under 1 year old,with rates of 91% (39/43)and 83% (20/24),respectively.SP strains exhibited complete sensitivity to vancomycin(100% ,75/75),linezolid(100% ,56/56),and meropenem(100% ,6/6).High sensitivity rates were also observed for levofloxacin(81% ,22/27),moxifloxacin(82% ,14/17),rifampicin(96% ,25/26),and chloramphenicol(91% ,21/23).However,low sensitivity rates were found for penicillin(16% ,11/68)and clindamycin(6% ,1/17),and SP strains were completely resistant to erythromycin(100% ,31/31).The rates of discharge with cure and improvement were 22.5% (36/160)and 66.2% (106/160),respectively,while 18 cases(11.3% )had adverse outcomes.Conclusions Pediatric PM is more common in children aged 3 months to under 3 years.Intracranial complications are more frequently observed in children under 1 year old.Fever is the most common clinical manifestation of PM,and subdural effusion/emphysema and hydrocephalus are the most frequent complications.Non-culture detection methods for cerebrospinal fluid can improve pathogen detection rates.Adverse outcomes can be noted in more than 10% of PM cases.SP strains are high sensitivity to vancomycin,linezolid,meropenem,levofloxacin,moxifloxacin,rifampicin,and chloramphenicol.[Chinese Journal of Contemporary Pediatrics,2024,26(2):131-138]

The purpose of this study was to investigate the regulatory effects of biofilm associated non-coding small RNA(sRNA)00085 on the survival and environmental fitness of Listeria monocytogenes.Homologous recombination technology was used to construct a deletion mutant strain(△sRNA 00085)and a complementary strain(C △sRNA 00085)of the sRNA00085 target gene.The differences in biological characteristics were compared among the standard strain,△sRNA 00085,and C△sRNA 00085.The deletion of sRNA00085 led to a significant decrease in biofilm formation capacity and sensitivity to several antibiotics,including penicillin,piperacillin,doxycycline,tetracycline,vancomycin,and cotrimoxazole.However,only the minimum inhibitory concentration(MIC)of tetracycline exhibited a significant decrease in △sRNA00085.Meanwhile,the decreased biofilm formation and antibiotic resistance of the sRNA00085 mutant were restored in the C△sRNA00085 strain.Furthermore,we investigated the transcription levels of tetracycline resistance-related genes in L.monocytogenes.Down-regu-lated transcription of the tetS gene but no significant difference in transcription of the tetA gene were observed in △sRNA 00085 compared with the standard strain and C△sRNA00085.Moreover,the elimination of sRNA00085 did not affect bacterial growth ability or sensitivity to disinfectants.These findings highlight that sRNA00085 plays an important role in the environ-mental adaptability of L.monocytogenes by affecting bacterial biofilm formation and resistance.

Objective:To investigate the psychological status of the outpatients in the andrology clinic and the effect of risk warning combined with multidisciplinary team(MDT)intervention on their satisfaction.Methods:Using convenience sampling,we enrolled 600 outpatients seeking medical attention in the Department of Andrology of our hospital from July to October 2022.We ran-domized the patients into a control(n=300)and an observation group(n=300),obtained their basic information,evaluated their psychological status with the Hospital Anxiety and Depression Scale(HADS),and assessed their satisfaction with the Xijing Hospital Outpatients'Satisfaction Questionnaire(HOSQ).The controls followed the routine procedure of treatment,while the patients in the ob-servation group received early warning before intervention based on their HADS scores.We provided normal medical care for those with HADS scores≤7,employed empathetic communication for those with HADS scores of 8-10,and conducted MDT intervention for those with HADS scores≥1l,followed by comparison of the patients'satisfaction with the outpatient service between the two groups.Results:There were no statistically significant differences in general conditions between the groups of patients(P＞0.05).The mean prevalence rate of anxiety and depression was 47.83％among the male subjects,lower in the control than in the observation group(47.00％vs 48.67％,P＞0.05),but higher in the patients with the education of junior high school or below(60.99％)than in those with that of senior high school(22.34％)and university or above(16.67％),and also higher in those aged 18-40 years(67.38％)than in those aged 41-60 years(51.82％)and over 60 years old(38.33％).A significantly higher rate of satisfaction with the outpatient service was found in the observation group than in the controls(97.18％vs 90.39％,P＜0.05).Conclusion:Anxie-ty and depression are prevalent among the outpatients in the andrology clinic,with a higher prevalence rate in those with lower educa-tion and at a younger age.Early risk warning combined with MDT intervention can improve the satisfaction of the patients.

Objective To explore the pattern of early expression and secretion of tissue factor(TF)in vascular endothelial cells induced by heat stress.Methods Thirty SPF-rated C57BL/6 male mice were randomly divided into five groups:the control group and groups of indicated recovery time,including 0,3,6,and 9 h in room temperature after heat stress(n=6).Mice in the heat stress groups were exposed to an animal incubator to reach 42.5℃for core body temperature for heat stroke.We analyzed the histopathological changes in the liver,lung,and kidney tissues with HE staining.We measured the TF mRNA in mice tissues by RT-qPCR and the plasma concentration of TF in mice with a commercial ELISA kit.Human umbilical vein endothelial cells(HUVECs)were placed in a culture incubator to build an in vitro heat stress model.HUVECs were divided into five groups,including a control group and groups of indicated recovery time,including 0,3,6,and 9 h after heat stress.We quantified the expression of TF mRNA and protein in HUVEC cells by RT-qPCR,Western blotting,and immunofluorescence and measured the secreted TF with a commercial ELISA kit.Results No significant pathological injury was observed in the tissues of the control group.Mice treated with heat stress had various degrees of structural injuries and hemorrhagic and inflammatory changes in multiple tissues.Compared to control group,the expression of TF mRNA significantly increased in the kidney of heat stress-treated mice with 0 and 3 h recovery time(1.719±0.018,1.241±0.178 vs.1.000±0.063),the lung with 3 h recovery time(2.444±0.511 vs.1.000±0.106)and the liver with 6 h recovery time(7.312±0.618 vs.1.000±0.147)(P<0.05).The concentration of TF in plasma also sustainedly elevated in mice with 0,3,6,and 9 h recovery time after heat stress as compared to control group[(132.426±17.920)pg/ml,(119.400±10.267)pg/ml,(107.374±13.495)pg/ml,(163.767±22.810)pg/ml vs.(75.479±13.831)pg/ml,respectively,P<0.01].The expression levels of TF mRNA were higher in heat stress HUVECs with 6 h and 9 h recovery time than the control cells(1.905±0.354,2.564±0.297 vs.1.000±0.097,P<0.01).Secreted TF in the supernatant from HUVECs treated with heat stress and different recovery time also increased significantly[(36.309±4.101)pg/ml,(38.425±5.484)pg/ml,(41.655±4.380)pg/ml,(43.586±4.718)pg/ml vs.(14.996±0.254)pg/ml,P<0.01].Conclusion Heat stress increased early expression and secretion of TF in vascular endothelial cells.Vascular endothelial cells may be a main source of circulating TF in heat stroke.