Aim To explore the antimicrobial activity of a novel R-type phage tail-like bacteriocin(PTLB)secreted by Enterobacter cloacae SHAMU191747 a-gainst methicillin-resistant Staphylococcus aureus(MR-SA).Methods Antagonistic activity of E.cloacae SHAMU191747 against MRS A was detected by LB agar plate antagonistic test and LB broth micro-fermentation test.The crude extract of fermentation supernatant of E.cloacae SHAMU191747 was prepared by ultra-high-speed centrifugation and density gradient centrifuga-tion.The novel R-type PTLB in the crude extract was detected by transmission electron microscopy.The an-timicrobial activity of the crude extract against MRSA was verified by LB agar plate spot-seeding method.The molecular weight of the novel R-type PTLB was detected by SDS-PAGE electrophoresis.Results E.cloacae SHAMU191747 secreted a novel R-type PTLB,and had a strong antagonistic effect on MRSA.The no-vel R-type PTLB had a molecular weight of approxi-mately 35 ku and could efficiently kill MRSA.The physical dimensions of its tail-sheath-uncontracted functional molecules were(142.7±4.3)×(13.8±0.6)nm,and those of the tail-sheath-contracted non-functional molecules were(57.7±1.2)×(20.8±1.5)nm.Conclusions The novel R-type PTLB pro-duced by E.cloacae SHAMU191747 can efficiently kill MRSA,and has the potential to be developed into a novel antimicrobial drug with great prospects for clini-cal application.

Objective To compare clinical efficacy of robot-assisted(RA)and remote sensing navigation alignment(RSNA)system-assisted total knee arthroplasty(TKA).Methods From March 2023 to June 2023,60 patients who underwent the first unilateral TKA due to severe knee osteoarthritis(KOA)were admitted and divided into RSNA group and RA group according to different treatment methods,with 30 patients in each group.There were 5 males and 25 females in RSNA group,aged from 56 to 81 years old with an average of(66.33±7.16)years old;body mass index(BM1)ranged from 19.87 to 38.54 kg·m-2 with an average of(28.40±6.18)kg·m-2;the courses of disease ranged from 5 to 36 months with an average of(18.20±8.98)months;RSNA system was used to assist the positioning of osteotomy.There were 7 males and 23 females in RA group,aged from 55 to 82 years old with an average of(67.83±8.61)years old;BMI ranged from 19.67 to 37.25 kg·m-2 with an aver-age of(28.01±4.89)kg·m-2;the courses of disease ranged from 3 to 33 months with an average of(17.93±9.20)months;RA was performed.Operation time,incision length,latent blood loss at 2 weeks after operation and incidence of lower extremity thrombosis were compared between two groups.Hip-knee ankle angle(HKAA),HKAA deviation,lateral distal femoral angle(LDFA),medial proximal tibial angle(MPTA)and posterior tibial slope(PTS)were compared between two groups;Western Ontario McMaster Universities Osteoarthritis Index(WOMAC)and Knee Society score(KSS)were used to evaluate functional recovery before operation,3 and 6 months after operation.Results The operation was performed successfully in both groups,and there were no serious complications such as vascular and nerve injury during operation.The wound healed well at stage Ⅰafter operation,and the follow-up time was 6 months.The operation time,latent blood loss at 2 weeks after operation and inci-sion length in RSNA group were(94.35±5.75)min,(130.54±17.53)mland(14.73±2.14)cm,respectively;while(102.57±6.88)min,(146.33±19.47)ml and(16.78±2.32)cm in RA group,respectively.RSNA group was better than RA group(P＜0.05).No deep vein thrombosis occurred in both groups at 2 weeks after operation,5 patients occurred intermuscular vein throm-bosisin in RSNA group and 8 patients in RA group,the difference was not statistically significant(P＞0.05).In RSNA group,HKAA,LDFA and MPTA were(173.00±5.54)°,(86.96±3.45)°,(82.79±3.35)° before operation,and(178.34±1.85)°,(89.92±0.42)°,(89.84±0.73)° at 1 week after operation,respectively.In RA group,HKAA,LDFA and MPTA were(173.31±6.48)°,(87.15±3.40)° and(82.99±3.05)° before operation,and(178.52±1.79)°,(90.03±0.39)° and(90.15±0.47)° at 1 week after operation,respectively.HKAA,LDFA and MPTA were significantly improved in both groups at 1 week after oper-ation(P＜0.05).There were no significant difference in HKAA,LDFA,MPTA and PTS between two groups before operation and 1 week after operation(P＞0.05).There was no significant difference in deviation distribution of HKAA at 1 week after op-eration(x2=2.61 1,P=0.456).There were no significant difference in WOMAC and KSS between two groups before operation,3 and 6 months after operation(P＞0.05),and postoperative WOMAC and KSS at 3 and 6 months between two groups were im-proved compared with those before operation(P＜0.05).Conclusion Both RA and RSNA system assisted TKA could obtain ac-curate osteotomy,RA has higher surgical accuracy,RSNA system assisted operation has less trauma,and operation is simpler.

Objective To explore clinical accuracy of remote sensing navigation alignment(RSNA)system in total knee arthroplasty(TKA)and its influence on postoperative clinical efficacy.Methods From May 2021 to May 2022,60 knee os-teoarthritis(KOA)patients with Kellgren-Lawrence(K-L)grade Ⅲ to Ⅳ treated by unilateral primary TKA were selected and divided into RSNA group and traditional operation group according to treatment methods,and 30 patients in each group.There were 6 males and 24 females in RSNA group,aged from 55 to 86 years old with an average of(68.06±8.23)years old;body mass index(BMI)ranged from 22.15 to 34.58 kg·m-2 with an average of(28.20±3.01)kg·m-2;the courses of disease ranged from 2 to 60 months with an average of(18.80±14.80)months;13 patients with grade Ⅲ and 17 patients with grade Ⅳaccording to K-L grading.In traditional operation group,there were 8 males and 22 females,aged from 57 to 85 years old with an average of(67.26±6.32)years old;BMI ranged from 23.94 to 34.55 kg·m-2 with an average of(27.49±2.32)kg·m-2;the courses of disease ranged from 3 to 60 months with an average of(21.30±16.44)months;14 patients with grade Ⅲ and 16 pa-tients with grade Ⅳ according to K-L grading.Western Ontario and McMaster Universities(WOMAC)osteoarthritis index and Knee Society score(KSS)were used to evaluate functional recovery of patients.Hip-knee-ankle angle(HKAA),distal femoral valgus angle(FVA)and distal fermoral flexion angle(DFFA)were measured before operation.HKAA and HKAA deviation angle were measured at 1 week after operation,and defective rate of lower limb force line,femur prosthesis valgus angle(FP-VA)and femoral prosthesis flexion angle(FPFA),respectively,were calculated.Results There were no serious complications such as vascular and nerve injury during operation,and wound healed at stage Ⅰ.Both groups were followed up for 6 months.There were no significant difference in WOMAC index,KSS,HKAA,FVA and DFFA between two groups before operation(P＞0.05).The force line defect rate,HKAA,HKAA deviation angle,FPVA deviation angle and FPFA of RSNA group were 6.7％,(178.74±1.56)°,(1.25±1.56)°,(1.84±0.16)° and(4.85±2.46)°,respectively;while in traditional operation group were 20％,(176.73±3.46)°,(3.27±3.46)°,(2.44±0.26)°,(6.60±1.86)°;the difference between two groups were statistically sig-nificant(P＜0.05).There were no significant difference in WOMAC index and KSS between two groups at 3 and 6 months after operation(P＞0.05).Conclusion RSNA system could reduce defective rate of lower limb force line,FPVA deviation angle and FPFA after TKA,which is more accurate and easy to operate than traditional intramedullary localization surgery while ensuring postoperative efficacy.

The genomic island(GI)characteristics and virulence factor differences of clinical isolates of Burkholderia pseudomallei in Hainan Province,China were analyzed to provide a scientific basis for diagnosis and treatment of melioidosis.In total,52 B.pseudomallei isolates were collected for detection of virulence-related GIs by PCR.The whole genome sequence annotation format file was submitted on Islandviwer 4 platform,and the genomes of the same species and close relatives were added for comparison.Two algorithms,SIGI-HMM and IslandPath-DIMOB,were integrated to predict GIs and sequence a-lignments were conducted to identify specific GIs and differences in virulence factors.The genomes of 52 clinical strains could be divided into three branches based on evolutionary distance,with 82.69％(43/52)of strains concentrated in branch 1.In to-tal,828 GIs were identified among the 52 B.pseudomallei genomes,which formed 157 GI clusters based on sequence similari-ty.GIs accounted for 2.05％-6.38％of the genome content.While GI clusters 1 and 2 were present in all strains,a total of 84(53.50％)GI clusters only clustered within a single genome isolate.Of 10 GI likely specific clusters,five were from the same genus,two from another genus,and three with uncertain origins.Moreover,25 GI clusters were associated with virulence,which included eight shared by B.pseudomallei BP76 and BP169,which had the highest number of virulence-associated GIs among all isolates.O the 52 B.pseudomallei isolates,variations were identified in the virulence genes fhaB1,fhaB2,BPSL1661,cheY1,wzM,tssH-5/clpV,tssA-5,boaA,and boaB.Comparisons of these findings with clinical isolates from Thailand and Australia showed that B.pseudomallei isolates from Hainan had significant differences in the sequences of boaA,boaB,cheY1,and chbp.Additionally,fhaB1,fhaB3,and bimA displayed significant variations specifically within the Australian isolates.B.pseudomallei GI was conserved and specific to Hainan.The identification of specific GI and virulence factors was useful to clarify the source of horizontal gene transfer and differences in virulence at the molecular level.

This study was aimed at exploring the epidemiological characteristics of plague,and the evolutionary relation-ships among the isolated plague strains in the Yunnan border area,to provide clues for further studying epidemic causes and ep-idemiological patterns.Plague epidemic data in the border area during the second epidemic period(1982-2007)were collected and analyzed with descriptive epidemiological methods.Whole genome sequences of 262 strains of Yersinia pestis in the border area were obtained for phylogenetic analysis.Plague outbreaks occurred in 17 counties(cities)among 25 border counties(cit-ies);a total of 552 epidemic foci and 123 human cases were identified.The 1.ORI2,1.ORI3,1.IN3,2.ANT and 2.MED geno-types were identified among Yersinia pestis isolated from the Yunnan border area,among which the 1.ORI2 population was dominant.A total of 258 strains of Yersinia pestis from the 1.OR12 population belonged to four subclusters.The Myanmar and Vietnam clade was embedded within the Yunnan clade in the overall phylogeny.The above results indicated that during the sec-ond period of the epidemic,the intensity of plague epidemics in Yunnan's border areas was high,showing a trend of devel-opment from west to south and east.Our findings indicated a risk of cross-border transmission of plague between Yunnan and neighboring countries;therefore,the surveillance,pre-vention,and control of plague in border areas should be strengthened.

This study was aimed at investigating the pathogenic and molecular characteristics of Klebsiella pneumoniae(KP)in fecal samples of diarrhea cases in a district of Beijing.Fecal samples from diarrhea cases in an outpatient department in a district of Beijing from 2018 to 2021 were collected,and used for isolation and culture of KP.The KP strains isolated strains were subjected to drug resistance phenotype testing and whole-genome sequencing.Multilocus sequence typing and whole-genome phyletic evolution analysis were performed on the sequencing results.The cases'epidemiological and clinical characteristics were analyzed.From 2018 to 2021,1 103 fecal samples were collected and detected.The total detection rate of KP was 10.43％(115/1 103),and the infection rate of KP mixed with other diarrhea-causing pathogens was 42.61％(49/115).The positivity rate was slightly high(12.47％,61/489)a-mong females and was highest in young adults 16-45 years of age.Small peaks were observed in January,April to May,and August to September.The gastrointestinal symptoms in cases were mainly nausea and watery stool,and the suspicious food was unknown.Ampicillin,tetracycline,and sulfafurazole were the top three antibiotics to which these 115 KP strains showed resistance,and 29 strains were resistant to multiple antibiotics.The strains were divided into 72 sequence types,among which ST23 was dominant.According to the phylogenetic tree,the strains were divided into four main branches,among which 14 ST23 strains had a very close genetic relationship with the highly virulent NTUH-K2044 reference strain.KP infection persisted in fecal samples from diarrhea cases in the district of Beijing.Women and young adults were particularly susceptible.The drug resistance of KP strains in this region was very serious,and the ST types were diverse.Moreover,the ST23 pathogenic strains were closely related to high virulence strains.

A quartz crystal microbalance(QCM)-systematic evolution of ligands by the exponential en-richment(SELEX)technique was developed to screen out aptamers with high affinity for arsenic(Ⅲ).A random single strand DNA library was designed and fixed on the mercaptoethylamine-modified crystal plate with arsenic(Ⅲ)as the target,and the free aptamer was captured in the solution,and the QCM-SELEX screening method was constructed.After 6 rounds of screening,the secondary library was se-quenced with high throughput method,and the 6S1 dissociation coefficient Kd value was 0.36 μmol/L based on QCM resonance frequency.Using 6S1 as a probe,the QCM biosensor was constructed for the detection of arsenic(Ⅲ).The sensor has a good linear relationship in the range of 0.01 μmol/L～0.2μmol/L,and the detection limit of arsenic(Ⅲ)is 5.2 nmol/L(3σ),indicatinggood selectivity.

Objective:To analyze the clinical characteristics and prognosis of patients with CD5+diffuse large B-cell lymphoma(DLBCL).Methods:The clinical data of 161 newly treated DLBCL patients in Gansu Provincial Hospital from January 2013 to January 2020 were retrospectively analyzed.According to CD5 expression,the patients were divided into CD5+group and CD5-group.The clinical characteristics and prognosis of the two groups were statistically analyzed.Results:The median age of patients in CD5+group was 62 years,which was higher than 56 years in CD5-group(P=0.048).The proportion of women in CD5+group was 62.96％,which was significantly higher than 41.79％in CD5-group(P=0.043).The proportion of patients with IPI score＞2 in CD5+group was 62.96％,which was higher than 40.30％in CD5-group(P=0.031).Survival analysis showed that the median overall survival and progression-free survival time of patients in CD5+group were 27(3-77)and 31(3-76)months,respectively,which were both shorter than 30(5-84)and 32.5(4-83)months in CD5-group(P=0.047,P=0.026).Univariate analysis showed that advanced age,positive CD5 expression,triple or double hit at initial diagnosis,high IPI score and no use of rituximab during chemotherapy were risk factors for the prognosis of DLBCL patients.Further Cox multivariate regression analysis showed that these factors were also independent risk factors except for advanced age.Conclusion:CD5+DLBCL patients have a worse prognosis than CD5-DLBCL patients.Such patients are more common in females,with advanced age and high IPI score,which is a special subtype of DLBCL.

Objective:To analyze the prognostic value of del(1p32)in patients with newly diagnosed multiple myeloma(MM).Methods:The clinical data of 341 newly diagnosed MM attended in Jiangsu Province Hospital were retrospective analyzed.Clinical characteristic combined with genetic features,especially del(1p32),were analyzed for survival and prognostic of patients.Results:Among the 341 patients with newly diagnosed MM,24(7.0％)patients were del(1p32)positive.The progression-free survival(PFS)and overall survival(OS)were significantly shorter in MM patients with del(1p3 2)than those without de1(1p32)(PFS:P＜0.001;OS:P＜0.001).The COX proportional-hazards model showed that del(1 p32)was an independent risk factor for PFS and OS of patients with MM.The patients with both 1q21 gain/amplification and del(1p32),as"double-hit chromosome 1",have worse prognosis than those with only 1q21 gain/amplification or only del(1 p32)(PFS:P＜0.001;OS:P＜0.001).Conclusion:Del(1p32)is an independent risk factor for PFS and OS of patients with MM.Del(1p32)detection should be widely used in the prognostic analysis for newly diagnosed MM patients.

Objective:To explore the gene mutations of Langerhans cell histiocytosis in children,and to analyze the correlation of BRAF V600E mutation with clinical features and prognosis of LCH,so as to provide reference for clinical diagnosis and treatment. Methods:Fluorescence PCR was used to detect gene mutations in paraffin-embedded tissue samples from 78 children with LCH,and the correlation of BRAF V600E mutation with clinical characteristics and prognosis of LCH in children was analyzed. Results:Among the 78 children,41 cases (52.6％) had BRAF V600E mutation,8 cases (10.3％) had MAP2K1 mutation,1 case (1.3％) had BRAF Exon 12 mutation,1 case (1.3％) had ARAF mutation,and 1 case (1.3％) had PIK3CA mutation. BRAF V600E mutation was not significantly correlated with sex,age,multisystem involvement,risk-organ involvement,CNS-risk lesions,and early treatment response in children with LCH (P>0.05),and it was also not significantly correlated with the recurrence and event-free survival (EFS) of children with LCH (P>0.05). Conclusion:LCH is an inflammatory myeloid tumor. BRAF V600E mutation is not correlated with clinical features,early treatment response,recurrence and prognosis of LCH.