Objective:To report the results of national surveillance on the distribution and antimicrobial resistance profile of clinical Gram-negative bacteria isolates from bloodstream infections in China in 2022.Methods:The clinical isolates of Gram-negative bacteria from blood cultures in member hospitals of national bloodstream infection Bacterial Resistant Investigation Collaborative System（BRICS）were collected during January 2022 to December 2022. Antibiotic susceptibility tests were conducted by agar dilution or broth dilution methods recommended by Clinical and Laboratory Standards Institute（CLSI）. WHONET 5.6 and SPSS 25.0 software were used to analyze the data.Results:During the study period，9 035 strains of Gram-negative bacteria were collected from 51 hospitals，of which 7 895（87.4%）were Enterobacteriaceae and 1 140（12.6%）were non-fermenting bacteria. The top 5 bacterial species were Escherichia coli（ n=4 510，49.9%）， Klebsiella pneumoniae（ n=2 340，25.9%）， Pseudomonas aeruginosa（ n=534，5.9%）， Acinetobacter baumannii complex（ n=405，4.5%）and Enterobacter cloacae（ n=327，3.6%）. The ESBLs-producing rates in Escherichia coli， Klebsiella pneumoniae and Proteus spp. were 47.1%（2 095/4 452），21.0%（427/2 033）and 41.1%（58/141），respectively. The prevalence of carbapenem-resistant Escherichia coli（CREC）and carbapenem-resistant Klebsiella pneumoniae（CRKP）were 1.3%（58/4 510）and 13.1%（307/2 340）；62.1%（36/58）and 9.8%（30/307）of CREC and CRKP were resistant to ceftazidime/avibactam combination，respectively. The prevalence of carbapenem-resistant Acinetobacter baumannii（CRAB）complex was 59.5%（241/405），while less than 5% of Acinetobacter baumannii complex was resistant to tigecycline and polymyxin B. The prevalence of carbapenem-resistant Pseudomonas aeruginosa（CRPA）was 18.4%（98/534）. There were differences in the composition ratio of Gram-negative bacteria in bloodstream infections and the prevalence of main Gram-negative bacteria resistance among different regions，with statistically significant differences in the prevalence of CRKP and CRPA（ χ2=20.489 and 20.252， P<0.001）. The prevalence of CREC，CRKP，CRPA，CRAB，ESBLs-producing Escherichia coli and Klebsiella pneumoniae were higher in provinicial hospitals than those in municipal hospitals（ χ2=11.953，81.183，10.404，5.915，12.415 and 6.459， P<0.01 or <0.05），while the prevalence of CRPA was higher in economically developed regions（per capita GDP ≥ 92 059 Yuan）than that in economically less-developed regions（per capita GDP <92 059 Yuan）（ χ2=6.240， P=0.012）. Conclusions:The proportion of Gram-negative bacteria in bloodstream infections shows an increasing trend，and Escherichia coli is ranked in the top，while the trend of CRKP decreases continuously with time. Decreasing trends are noted in ESBLs-producing Escherichia coli and Klebsiella pneumoniae. Low prevalence of carbapenem resistance in Escherichia coli and high prevalence in CRAB complex have been observed. The composition ratio and antibacterial spectrum of bloodstream infections in different regions of China are slightly different，and the proportion of main drug resistant bacteria in provincial hospitals is higher than those in municipal hospitals.

Objective:To report the results of national surveillance on the distribution and antimicrobial resistance profile of clinical Gram-positive bacteria isolates from bloodstream infections in China in 2022.Methods:The clinical isolates of Gram-positive bacteria from blood cultures in member hospitals of National Bloodstream Infection Bacterial Resistant Investigation Collaborative System（BRICS）were collected during January 2022 to December 2022. Antibiotic susceptibility tests were conducted by agar dilution or broth dilution methods recommended by Clinical and Laboratory Standards Institute（CLSI）. WHONET 5.6 and SPSS 25.0 software were used to analyze the data.Results:A total of 3 163 strains of Gram-positive pathogens were collected from 51 member units，and the top five bacteria were Staphylococcus aureus（ n=1 147，36.3%），coagulase-negative Staphylococci（ n=928，29.3%）， Enterococcus faecalis（ n=369，11.7%）， Enterococcus faecium（ n=296，9.4%）and alpha-hemolyticus Streptococci（ n=192，6.1%）. The detection rates of methicillin-resistant Staphylococcus aureus（MRSA）and methicillin-resistant coagulase-negative Staphylococci（MRCNS）were 26.4%（303/1 147）and 66.7%（619/928），respectively. No glycopeptide and daptomycin-resistant Staphylococci were detected. The sensitivity rates of Staphylococcus aureus to cefpirome，rifampin，compound sulfamethoxazole，linezolid，minocycline and tigecycline were all >95.0%. Enterococcus faecium was more prevalent than Enterococcus faecalis. The resistance rates of Enterococcus faecium to vancomycin and teicoplanin were both 0.5%（2/369），and no vancomycin-resistant Enterococcus faecium was detected. The detection rate of MRSA in southern China was significantly lower than that in other regions（ χ2=14.578， P=0.002），while the detection rate of MRCNS in northern China was significantly higher than that in other regions（ χ2=15.195， P=0.002）. The detection rates of MRSA and MRCNS in provincial hospitals were higher than those in municipal hospitals（ χ2=13.519 and 12.136， P<0.001）. The detection rates of MRSA and MRCNS in economically more advanced regions（per capita GDP≥92 059 Yuan in 2022）were higher than those in economically less advanced regions（per capita GDP<92 059 Yuan）（ χ2=9.969 and 7.606， P=0.002和0.006）. Conclusions:Among the Gram-positive pathogens causing bloodstream infections in China， Staphylococci is the most common while the MRSA incidence decreases continuously with time；the detection rate of Enterococcus faecium exceeds that of Enterococcus faecalis. The overall prevalence of vancomycin-resistant Enterococci is still at a low level. The composition ratio of Gram-positive pathogens and resistant profiles varies slightly across regions of China，with the prevalence of MRSA and MRCNS being more pronounced in provincial hospitals and areas with a per capita GDP≥92 059 yuan.

Objective To develop a portable field infusion kit for first aid to meet the treatment requirements in field conditions.Methods The infusion kit had its frame made of third-generation carbon fiber material and was composed of a lid and a body.The lid was equipped with embedded handles on the outer surface,a medicine module consisting of 12 mesh bags on the inner surface and LED lights on the inner and outer front side walls.The kit body had three storage layers in its upper,middle and lower parts,of which the upper layer was for supplies of infusion and hemostatic dressing,the middle layer was for medical instruments and soft bags of liquid for first aid,and the lower layer was for medical waste and sharp instruments,and the bottom of the kit was provided with telescopic drawbars and invisible rollers.Results The first-aid infusion kit facilitated the storage and utilization of kinds of infusion supplies,and lowered time consumption and workloads for transport.Conclusion The first-aid infusion kit gains advantages in reasonable layout,comprehensive functions and convenient operation,and thus is worhty promoting for casualty treatment in field conditions.[Chinese Medical Equipment Journal,2024,45(7):115-117]

Microplastics pose a serious threat to the environment and human health,but the circulating distribution and transport processes of microplastics in organisms have not been fully assessed.Therefore,it is of great significance to construct a probe that can image trace microplastics and visually monitor their circulation and transport in vivo.Afterglow semiconducting polymers are attractive for applications in biological imaging as they do not contain heavy metal ions,are easy to biodegrade and allow high signal-to-noise ratio afterglow imaging without continuous excitation.In this study,with styrene as reaction monomer,polyvinylpyrrolidone as surfactant,and sodium persulfate as initiator,afterglow polystyrene microspheres for in vivo imaging of microplastics were prepared.During the polymerization process,poly[(9,9-di(2-ethylhexyl)-9H-fluo-rene-2,7-vinylene)-co-(1-methoxy-4-(2-ethylhexyloxy)-2,5-phenylenevinylene)](PF-MEHPPV)and photosensitizer silicon 2,3-naphthalocyanine bis(trihexylsilyloxide)(NCBS)were co-doped into polystyrene microspheres.The prepared afterglow polystyrene microspheres exhibited an afterglow duration of 96 h and a tissue penetration depth of 1.8 cm.It was found that co-doping of PF-MEHPPV and NCBS had little effect on the particle size and Zeta potential of the microspheres,and allowed to monitor the afterglow luminescence signal in vivo for 24 h.Imaging of mouse organs after anatomy showed that the afterglow signal was still observed in the stomach of mice 48 h after gavage.This study provided a new method for imaging and tracing microplastics in vivo.

Objective To compare the repair effects of different doses of human umbilical cord mesenchymal stem cells(hUC-MSCs)on white matter injury(WMI)in neonatal rats.Methods Two-day-old Sprague-Dawley neonatal rats were randomly divided into five groups:sham operation group,WMI group,and hUC-MSCs groups(low dose,medium dose,and high dose),with 24 rats in each group.Twenty-four hours after successful establishment of the neonatal rat white matter injury model,the WMI group was injected with sterile PBS via the lateral ventricle,while the hUC-MSCs groups received injections of hUC-MSCs at different doses.At 14 and 21 days post-modeling,hematoxylin and eosin staining was used to observe pathological changes in the tissues around the lateral ventricles.Real-time quantitative polymerase chain reaction was used to detect the quantitative expression of myelin basic protein(MBP)and glial fibrillary acidic protein(GFAP)mRNA in the brain tissue.Immunohistochemistry was employed to observe the expression levels of GFAP and neuron-specific nuclear protein(NeuN)in the tissues around the lateral ventricles.TUNEL staining was used to observe cell apoptosis in the tissues around the lateral ventricles.At 21 days post-modeling,the Morris water maze test was used to observe the spatial learning and memory capabilities of the neonatal rats.Results At 14 and 21 days post-modeling,numerous cells with nuclear shrinkage and rupture,as well as disordered arrangement of nerve fibers,were observed in the tissues around the lateral ventricles of the WMI group and the low dose group.Compared with the WMI group,the medium and high dose groups showed alleviated pathological changes;the arrangement of nerve fibers in the medium dose group was relatively more orderly compared with the high dose group.Compared with the WMI group,there was no significant difference in the expression levels of MBP and GFAP mRNA in the low dose group(P＞0.05),while the expression levels of MBP mRNA increased and GFAP mRNA decreased in the medium and high dose groups.The expression level of MBP mRNA in the medium dose group was higher than that in the high dose group,and the expression level of GFAP mRNA in the medium dose group was lower than that in the high dose group(P＜0.05).Compared with the WMI group,there was no significant difference in the protein expression of GFAP and NeuN in the low dose group(P＞0.05),while the expression of NeuN protein increased and GFAP protein decreased in the medium and high dose groups.The expression of NeuN protein in the medium dose group was higher than that in the high dose group,and the expression of GFAP protein in the medium dose group was lower than that in the high dose group(P＜0.05).Compared with the WMI group,there was no significant difference in the number of apoptotic cells in the low dose group(P＞0.05),while the number of apoptotic cells in the medium and high dose groups was less than that in the WMI group,and the number of apoptotic cells in the medium dose group was less than that in the high dose group(P＜0.05).Compared with the WMI group,there was no significant difference in the escape latency time in the low dose group(P＞0.05);starting from the third day of the latency period,the escape latency time in the medium dose group was less than that in the WMI group(P＜0.05).The medium and high dose groups crossed the platform more times than the WMI group(P＜0.05).Conclusions Low dose hUC-MSCs may yield unsatisfactory repair effects on WMI in neonatal rats,while medium and high doses of hUC-MSCs have significant repair effects,with the medium dose demonstrating superior efficacy.[Chinese Journal of Contemporary Pediatrics,2024,26(4):394-402]

Objective To investigate the risk factors for bronchopulmonary dysplasia(BPD)in twin preterm infants with a gestational age of<34 weeks,and to provide a basis for early identification of BPD in twin preterm infants in clinical practice.Methods A retrospective analysis was performed for the twin preterm infants with a gestational age of<34 weeks who were admitted to 22 hospitals nationwide from January 2018 to December 2020.According to their conditions,they were divided into group A(both twins had BPD),group B(only one twin had BPD),and group C(neither twin had BPD).The risk factors for BPD in twin preterm infants were analyzed.Further analysis was conducted on group B to investigate the postnatal risk factors for BPD within twins.Results A total of 904 pairs of twins with a gestational age of<34 weeks were included in this study.The multivariate logistic regression analysis showed that compared with group C,birth weight discordance of>25%between the twins was an independent risk factor for BPD in one of the twins(OR=3.370,95%CI:1.500-7.568,P<0.05),and high gestational age at birth was a protective factor against BPD(P<0.05).The conditional logistic regression analysis of group B showed that small-for-gestational-age(SGA)birth was an independent risk factor for BPD in individual twins(OR=5.017,95%CI:1.040-24.190,P<0.05).Conclusions The development of BPD in twin preterm infants is associated with gestational age,birth weight discordance between the twins,and SGA birth.

Objective To monitor the susceptibility of clinical isolates to antimicrobial agents in tertiary hospitals in major regions of China in 2022.Methods Clinical isolates from 58 hospitals in China were tested for antimicrobial susceptibility using a unified protocol based on disc diffusion method or automated testing systems.Results were interpreted using the 2022 Clinical &Laboratory Standards Institute(CLSI)breakpoints.Results A total of 318 013 clinical isolates were collected from January 1,2022 to December 31,2022,of which 29.5％were gram-positive and 70.5％were gram-negative.The prevalence of methicillin-resistant strains in Staphylococcus aureus,Staphylococcus epidermidis and other coagulase-negative Staphylococcus species(excluding Staphylococcus pseudintermedius and Staphylococcus schleiferi)was 28.3％,76.7％and 77.9％,respectively.Overall,94.0％of MRSA strains were susceptible to trimethoprim-sulfamethoxazole and 90.8％of MRSE strains were susceptible to rifampicin.No vancomycin-resistant strains were found.Enterococcus faecalis showed significantly lower resistance rates to most antimicrobial agents tested than Enterococcus faecium.A few vancomycin-resistant strains were identified in both E.faecalis and E.faecium.The prevalence of penicillin-susceptible Streptococcus pneumoniae was 94.2％in the isolates from children and 95.7％in the isolates from adults.The resistance rate to carbapenems was lower than 13.1％in most Enterobacterales species except for Klebsiella,21.7％-23.1％of which were resistant to carbapenems.Most Enterobacterales isolates were highly susceptible to tigecycline,colistin and polymyxin B,with resistance rates ranging from 0.1％to 13.3％.The prevalence of meropenem-resistant strains decreased from 23.5％in 2019 to 18.0％in 2022 in Pseudomonas aeruginosa,and decreased from 79.0％in 2019 to 72.5％in 2022 in Acinetobacter baumannii.Conclusions The resistance of clinical isolates to the commonly used antimicrobial agents is still increasing in tertiary hospitals.However,the prevalence of important carbapenem-resistant organisms such as carbapenem-resistant K.pneumoniae,P.aeruginosa,and A.baumannii showed a downward trend in recent years.This finding suggests that the strategy of combining antimicrobial resistance surveillance with multidisciplinary concerted action works well in curbing the spread of resistant bacteria.

Objective:To study the incidence and risk factors of herpes zoster in patients with multiple myeloma and to evaluate the preventive effect of antiviral therapy.Methods:The clinical features of multiple myeloma patients with herpes zoster were retrospectively analyzed,the risk factors of herpes zoster and the effect of antiviral prophylaxis were analyzed.Results:Among 180 patients with multiple myeloma,23 cases developed herpes zoster(12.8％).The incidence of herpes zoster was 19.1％in patients with renal dysfunction and 23.5％after autologous hematopoietic stem cell transplantation(ASCT).The incidence of herpes zoster was higher in patients receiving bortezomib-containing regimens(21/137,15.3％)than that in those without bortezomib(2/43,4.7％),but there was no statistical difference(P=0.067).Antiviral prophylaxis was associated with fewer zoster infections,8/111(7.2％)developed herpes zoster in patients who received antiviral prophylaxis,and 15/69(21.7％)in those receiving no prophylaxis(P=0.005).65.2％of patients with herpes zoster did not receive antiviral prophylaxis.Multivariate analysis showed that bortezomib treatment,AHSCT and renal dysfunction were independent risk factors for multiple myeloma with herpes zoster,while antiviral prophylaxis was independently associated with reducing the risk of herpes zoster.Herpes zoster had no effect on OS in patients with multiple myeloma.Conclusion:The risk of herpes zoster in multiple myeloma patients was increased.Antiviral prophylaxis can reduce the risk of herpes zoster in patients on bortezomib-based therapy.

Objective:To evaluate the clinical and prognostic value of prothrombin time(PT)and activated partial thromboplastin time(APTT)in newly diagnosed patients with multiple myeloma(MM).Methods:The clinical data of 116 newly diagnosed MM patients in the Second Hospital and Third Hospital of Shanxi Medical University from October 2014 to March 2022 were analyzed retrospectively,and the patients were divided into two groups:normal PT and APTT group and prolonged PT or APTT group.The differences in sex,age,classification,staging,bleeding events,laboratory indicators[including hemoglobin(Hb),platelet count(PLT),serum calcium,serum albumin(ALB),lactate dehydrogenase(LDH),serum creatinine and β 2-microglobulin],and cytogenetic characteristics between the two groups of patients were compared.The effect of prolonged PT or APTT on survival of patients with MM was analyzed.Results:Compared with patients in normal PT and APTT group,patients in prolonged PT or APTT group were more likely to experience bleeding events(x2=5.087,P=0.024),with lower ALB levels(x2=4.962,P=0.026)and PLT levels(x2=4.309,P=0.038),and higher serum calcium levels(x2=5.056,P=0.025).The positive rates of del17p,del13q and 1q21+in prolonged PT or APTT group were higher than those in normal PT and APTT group,but the difference was not statistically significant(P＞0.05).K-M survival analysis showed that the prolonged PT or APTT group had a shorter median progression-free survival(PFS)(P=0.032)and overall survival(OS)(P=0.032).Multivariate Cox analysis showed that prolonged PT or APTT(HR=2.1 16,95％CI:1.025-4.372,P=0.043)and age ≥65 years(HR=2.403,95％CI:1.195-4.836,P=0.014)were independent risk factor for OS in newly diagnosed MM patients.However,prolonged PT or APTT had no significant effect on PFS of newly diagnosed MM patients(HR=1.162,95％CI:0.666-2.026,P=0.597).Conclusion:Newly diagnosed MM patients with prolonged PT or APTT have worse clinical indicators,shorter PFS and OS.Prolonged PT or APTT is an independent risk factor for OS in MM patients.

Objective:To explore the value of REG3α,sST2 and TNFR1 in peripheral blood for risk stratification and prognostic evaluation of acute graft-versus-host disease(aGVHD)after allogeneic hematopoietic stem cell transplantation(allo-HSCT)in children.Methods:From January 2020 to March 2022,70 children with aGVHD after allo-HSCT in the First Affiliated Hospital of Zhengzhou University were selected as the research objects,of which 50 cases were mild aGVHD(grade Ⅰ-Ⅱ)and 20 cases were severe aGVHD(grade Ⅲ-Ⅳ).30 healthy children who underwent physical examinations in our hospital during the same period were selected as the control group.Luminex platform was used to detect the protein expression levels of REG3α,sST2 and TNFR1 during aGVHD occurrence,and the differences between the three groups were analyzed by one-way ANOVA.According to the outcome of aGVHD treatment within 28 days,the patients were divided into a good prognosis group of 58 cases and a poor prognosis group of 12 cases.The ROC curve was used to analyze the value of REG3α,sST2 and TNFR1 in predicting the prognosis of children with aGVHD.Results:The peripheral blood levels of REG3α,sST2 and TNFR1 in the mild aGVHD and severe aGVHD groups were significantly higher than those in the control group(P＜0.05),and those in the severe aGVHD group were significantly higher than those in the mild aGVHD group(P＜0.05).Compared with the good prognosis group,the peripheral blood levels of REG3α,sST2 and TNFR1 in the poor prognosis group were significantly higher(t=9.27,3.33,2.97;P＜0.01).ROC curve analysis showed that the area under the curve(AUC),sensitivity and specificity of the combined detection of REG3α,sST2 and TNFR1 in predicting the prognosis of children with aGVHD were higher than those of the above indicators detected alone or in pairs.Conclusion:The expression levels of REG3α,sST2 and TNFR1 were related to the severity of aGVHD.The combination of REG3α,sST2 and TNFR1 has a high clinical value in predicting the prognosis of children with aGVHD,which is expected to provide a reliable reference for clinical evaluation of the prognosis of children with aGVHD.