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 investigate the correlation of miRNA-181b (miR-181b) and prognostic factors of myelodysplastic syndrome (MDS), to predict target gene and main biological functions of miR-181b, and to evaluate the risk prediction ability of miR-181b in MDS.Methods:The samples of 131 bone marrow in MDS patients who followed the criteria of World Health Organization (WHO) classification (2016) from the Blood Diseases Hospital, Chinese Academy of Medical Sciences between January 2019 and September 2019 were collected, and the clinical data including routine blood test results, related gene test results of blood diseases were retrospectively analyzed. The expression levels of miR-181b in all bone marrow samples were detected by using quantitative real-time polymerase chain reaction (qRT-PCR). According to the international prognostic scoring system (IPSS), WHO classification-based prognostic scoring system (WPSS) and revised IPSS (IPSS-R), the patients were divided into different groups by the risk grade, and the expression differences of miR-181b in different risk groups were compared, and the correlation between the expressions of miR-181b and partial prognostic factors, including white blood cell (WBC), hemoglobin (Hb), platelet (Plt), absolute neutrophil count(ANC), myeloblast and gene mutations was analyzed. Bioinformatics online tool TargetScan was used to make target gene prediction and the potential function of miR-181b.Results:The expression levels of miR-181b was increased with the increasing risk of IPSS, WPSS and IPSS-R, and there were statistically significant differences in miR-181b expression levels of different risk groups in different scoring systems (all P < 0.01). There was a positive correlation between the expression level of miR-181b and the scores of the three prognostic scoring systems (r was 0.437, 0.368, 0.327; all P = 0.001); miR-181b expression was positively correlated with the proportion of bone marrow myeloblasts ( r = 0.450, P < 0.01) and was negatively correlated with Plt ( r = -0.199, P = 0.024). And miR-18b was not associated with WBC, Hb, ANC, and related gene mutations of blood diseases (all P > 0.05). A total of 1 363 potential target genes of miR-181b were predicted by using bioinformatics, and biological processes of these target genes were mainly enriched in transcription regulation, RNA metabolism regulation. Among them, 22 target genes were related to the hematological malignancies, including RUNX1, ASXL2, NRAS, ATM and KRAS, which have been previously confirmed to be related to MDS. The relative expression level [the median ( P25, P75)] of miR-181b in patients who had those hematological malignancies related to miR-181b target gene mutation (32 cases) was 1.33(0.63, 1.60), which was higher than that in patients without mutation (99 cases) [0.85 (0.49, 1.38)], and the difference was statistically significant ( Z = 2.285, P = 0.022). Conclusions:miR-181b has a correlation with the risk grade of prognostic scoring systems in MDS, and it may be involved in the molecular biology pathogenesis of MDS.

Objective To investigate the antimicrobial resistance profile of the clinical isolates collected from selected hospitals across China. Methods Twenty-nine general hospitals and five children's hospitals were involved in this program. Antimicrobial susceptibility testing was carried out according to a unified protocol using Kirby-Bauer method or automated systems. Results were interpreted according to CLSI 2017 breakpoints. Results A total of 190 610 clinical isolates were collected from January to December 2017, of which gram negative organisms accounted for 70.8％ (134 951/190 610) and gram positive cocci 29.2％ (55 649/190 610). The prevalence of methicillin-resistant strains was 35.3％ in S. aureus (MRSA) and 80.3％ in coagulase negative Staphylococcus (MRCNS) on average. MR strains showed much higher resistance rates to most of the other antimicrobial agents than MS strains. However, 91.6％ of MRSA strains were still susceptible to trimethoprim-sulfamethoxazole, while 86.2％ of MRCNS strains were susceptible to rifampin. No staphylococcal strains were found resistant to vancomycin. E. faecalis strains showed much lower resistance rates to most of the drugs tested (except chloramphenicol) than E. faecium. Vancomycin-resistant Enterococcus (VRE) was identified in both E. faecalis and E. faecium. The identified VRE strains were mainly vanA, vanB or vanM type based on phenotype or genotype. The proportion of PSSP or PRSP strains in the non-meningitis S.pneumoniae strains isolated from children decreased but the proportion of PISP strains increased when compared to the data of 2016. Enterobacteriaceae strains were still highly susceptible to carbapenems. Overall, less than 10％ of these strains (excluding Klebsiella spp.) were resistant to carbapenems. The prevalence of imipenem-resistant K. pneumoniae increased from 3.0％ in 2005 to 20.9％ in 2017, and meropenem-resistant K. pneumoniae increased from 2.9％ in 2005 to 24.0％ in 2017, more than 8-fold increase. About 66.7％ and 69.3％ of Acinetobacter (A. baumannii accounts for 91.5％) strains were resistant to imipenem and meropenem, respectively. Compared with the data of year 2016, P. aeruginosa strains showed decreasing resistance rate to carbapenems. Conclusions Bacterial resistance is still on the rise. It is necessary to strengthen hospital infection control and stewardship of antimicrobial agents. The communication between laboratorians and clinicians should be further improved in addition to surveillance of bacterial resistance.

Objective: Analysis of the molecular characteristics of eosinophilia. Methods: Targeting sequence to 24 patients with chronic eosinophilic leukemia (CEL) with rearrangement of PDGFRA, PDGFRB, or FGFR1 and 62 patients with hyper-eosinophilic syndrome (HES). Mutation annotation and analysis of amino acid mutation using authoritative databases to speculate on possible pathogenic mutation. Results: Thirty-seven kinds of clonal variant were detected from 17 patients with CEL, no recurrent mutation site and hot spot region were found. No pathogenic mutation was detected in 19 patients with PDGFRA rearrangement, but pathogenic mutations of ASXL1, RUNX1 and NRAS were detected from 2 patients with FGFR1 rearrangement who progressed to acute myeloid leukemia and 1 patient with PDGFRB rearrangement who progressed to T lymphoblastic lymphoma, respectively. One hundred and two kinds of clonal abnormalities were detected in 49 patients with HES. The main hot spot mutation regions included: CEBPA Exon1, TET2 Exon3, ASXL1 Exon12, IDH1 Y208C, and FGFR3 L164V. CRRLF2 P224L and PDGFRB R370C point mutations were detected separately in 2 patients with HES who treated with imatinib monotherapy and achieved hematologic remission. Conclusion The pathogenesis of CEL with PDGFRA, PDGFRB or FGFR1 rearrangement is usually single, and the progression of the disease may involve other driver mutation. A variety of genes with hot mutation regions may be involved in the pathogenesis of HES, and some mutation sites are sensitive to tyrosine kinase inhibitors.

Objective To evaluate the changing pattern of antibiotic resistance inKlebsiella strains isolated from the patients in 19 hospitals across China based on the data from CHINET Antimicrobial Resistance Surveillance Program during the period from 2005 through 2014.Methods Kirby-Bauer disk diffusion and automated susceptibility testing methods were used to test the susceptibility ofKlebsiella isolates to the commonly used antibiotics. The results were interpreted according to the criteria of the Clinical and Laboratory Standards Institute (CLSI) Performance Standards for Antimicrobial Susceptibility Testing (CLSI-2014).Results A total of 61 406Klebsiella strains were identified between 2005 and 2014, includingK. pneumoniae (56 281 strains), K. oxytoca(4 779),Klebsiella pneumoniae subsp.Ozaenae (300) and otherKlebsiella species (46). Most (89.0%, 54 664/61 406) of theKlebsiella strains were isolated from inpatients, and 60.0% (36 835/61 406) were from respiratory tract speciems. About 16.7% (10 248/61 406) of the strains were isolated from pediatric patients aged 0-17 years and 83.3% (51 158/61 406) from adult patients. The prevalence ofKlebsiella spp. increased with time from 10.1% in 2005 to 14.3% in 2014. Based on the surveillance data during the 10-year period, we found a marked increase of resistance to imipenem (2.9% to 10.5%) and meropenem (2.8% to 13.4%) inKlebsiella spp. The prevalence of ESBLs-producing isolates inK. pneumoniae andK. oxytoca decreased from 39.0% in 2005 to 30.1% in 2014. The resistance to amikacin, ceftazidime, ciprolfoxacin, pipracillin-tazobactam and cefoperazone-sulbactam was on decline. The resistance rate to cefotaxime remained high about 49.5%. Carbapenem resistantance was identiifed in 5 796 (9.4%) of the isolates, including 5 492 strains ofK. pneumoniae and 280 strains ofK. oxytoca. Overall, 4 740 (7.8%) strains were identiifed as extensively-drug resistant (XDR), including 4 520 strains ofK. pneumoniae and 202 strains ofK. oxytoca. The carbapenem-resistant strains showed high (>60%) resistance rate to majority of the antimicrobial agents tested, but relatively low resistance to tigecycline (16.8%), amikacin (54.4%), and trimethoprim-sulfamethoxazole (55.5%).Conclusions During the 10-year period from 2005 through 2014, carbapenem resistance amongKlebsiella isolates has increased dramatically in the hospitals across China. The level of resistance to other antibiotics remains stable.

Objective To investigate the susceptibility and resistance of clinical isolates from hospitals in several regions of China .Methods Fifteen general hospitals and two children′s hospitals were involved in this program . Antimicrobial susceptibility testing was carried out according to a unified protocol using Kirby‐Bauer method or automated systems .Results were analyzed according to CLSI 2014 breakpoints .Results A total of 78 955 clinical isolates were collected from January to December 2014 ,of which gram negative organisms and gram positive cocci accounted for 72 .6% and 27 .4% ,respectively . Methicillin‐resistant strains in S .aureus(MRSA)and coagulase negative Staphylococcus(MRCNS)accounted for an average of 44 .6% and 83 .0 % ,respectively .The resistance rates of methicillin‐resistant strains to β‐lactams and other antimicrobial agents were much higher than those of methicillin‐susceptible strains .However ,92 .0% of MRSA strains were still susceptible to trimethoprim‐sulfamethoxazole ,while 85 .6% of MRCNS strains were susceptible to rifampin .No staphylococcal strains were found resistant to vancomycin ,teicoplanin or linezolid .In Enterococcus spp .,the resistance rates of E .f aecalis strains to most tested drugs (except chloramphenicol) were much lower than those of E . f aecium .Some strains of both species were resistant to vancomycin .Vancomycin resistant strains of E . f aecalis and E . f aecium were mainly V anA ,V anB or V anM type based on their phenotype or genotype .Regarding non‐meningitis S .pneumoniae strains ,the prevalence of penicillin‐susceptible S .pneumoniae strains isolated from both adults and children were higher than those isolated in 2013 ,but the prevalence of penicillin‐intermediate S . pneumoniae or penicillin‐resistant S . pneumoniae strains decreased . The prevalence of ESBLs producingstrainswas55.8% in E.coliand29.9% in Klebsiellaspp.(K.pneumoniaeand K.oxytoca)and24.0% in Proteus mirabilis isolates on average . ESBLs‐producing Enterobacteriaceae strains were more resistant than non‐ESBLs‐producing strains in terms of antibiotic resistance rates . The strains of Enterobacteriaceae were still highly susceptible to carbapenems .Overall less than 10 % of these strains were resistant to carbapenems . About 62 .4% and 66 .7% of Acinetobacter spp .(A .baumannii accounts for 93 .0 % ) strains were resistant to imipenem and meropenem ,respectively . Compared with the data of year 2013 ,extensively‐drug resistant strains in K . pneumoniae and A .baumannii increased . Conclusions The antibiotic resistance of clinical bacterial isolates is growing .The disseminated multi‐drug or pan‐drug resistant strains in a special region poses a serious threat to clinical practice and implies the importance of strengthening infection control .

OBJECTIVETo explore the application of BIOMED- 2 standardized immunoglobulin (Ig) gene rearrangement system in the diagnosis of multiple myeloma (MM), and the significance of clonality analysis by multiplex-PCR amplifications.

METHODSA total of 167 cases of MM bone marrow samples from 2009 to 2013, and 20 cases of reactive plasmacytosis used as the controls were included in this study. Multiplex-PCR amplifications were performed and the Ig gene rearrangements were analyzed using BIOMED-2 standardized clonality analysis system.

RESULTS① Of 167 MM cases, 107 showed IgH VH-JH rearrangement, 33 showed IgH DH-JH rearrangement, and 30% showed IgH DH-JH rearrangement in 60 IgH VH-JH rearrangement negative MM cases. The difference was statistically significant between IgH VH-JH rearrangement positive and negative cases (14.0% vs 30.0%, P=0.032). The total positive rate of IgH VH-JH, IgH DH-JH and IgK was 94.6%. The 20 reactive plasmacytosis (RP) cases showed negative Ig gene rearrangement. 2 of 167 MM cases, 9 (5.4%) showed clonal IgH rearrangement by agarose electrophoresis were confirmed as polyclonality by capillary electrophoresis. ③ Of 53 MM cases who have been detected by Ig gene rearrangement system and fluorescence in situ hybridization (FISH) for IgH simultaneously, 36 showed IgH rearrangement, 26 showed FISH IgH positive, and the difference was statistically significant (67.9% vs 49.1%, P=0.049).

CONCLUSIONCombined detection of IgH VH- JH, IgH DH- JH and IgK could improve the positive rate of MM clonality dramatically, and measurement of IgH DH-JH rearrangement was more important in the IgH VH- JH negative cases. Ig gene rearrangement system was a faster and more sensitive method than FISH IgH. Application of BIOMED- 2 standardized immunoglobulin (Ig) gene rearrangement system is of significance for MM diagnosis.

Humans ; Immunoglobulins ; genetics ; In Situ Hybridization, Fluorescence ; Multiple Myeloma ; diagnosis ; genetics ; Polymerase Chain Reaction ; V(D)J Recombination

Objective To investigate the susceptibility and resistance of clinical isolates collected from hospitals in several regions of China . Methods Fourteen general hospitals and two children ’ s hospitals were involved in this program . Antimicrobial susceptibility testing was carried out according to a unified protocol using Kirby-Bauer method or automated Systems .Results were analyzed according to CLSI 2013 breakpoints .Results A total of 84 572 clinical isolates were collected from January to December 2013 ,of which gram negative organisms and gram positive cocci accounted for 73 .0% and 27 .0%respectively .Methicillin-resistant strains in S .aureus (MRSA) and coagulase negative Staphylococcus (MRCNS) accounted for an average of 45 .2% and 73 .5% respectively .The resistance rates of methicillin-resistant strains to β-lactams and other antimicrobial agents were much higher than those of methicillin-susceptible strains .However ,92 .2% of MRSA strains were still susceptible to trimethoprim-sulfamethoxazole while 87 .4% of MRCNS strains were susceptible to rifampin . No staphylococcal strains were found resistant to vancomycin ,teicoplanin or linezolid .In Enterococcus spp .,the resistance rates of E . f aecalis strains to most tested drugs (except chloramphenicol) were much lower than those of E . f aecium .Some strains of both species were resistant to vancomycin .Vancomycin-resistant strains of E . f aecalis and E . f aecium were mainly VanA type based on their phenotype .Regarding non-meningitis S . pneumoniae strains ,the prevalence of penicillin-susceptible S . pneumoniae and penicillin-intermediate S . pneumoniae strains isolated from both adults and children were lower than those isolated in 2012 ,but the prevalence of penicillin-resistant S .pneumoniae strains increased .The prevalence of ESBLs producing strains was 54 .0% in E .coli ,31 .8% in Klebsiella spp .(K .pneumoniae and K .oxytoca) and 16 .5% in Proteus mirabilis isolates on average . ESBLs-producing Enterobacteriaceae strains were more resistant than non-ESBLs-producing strains in terms of antibiotic resistance rates .The strains of Enterobacteriaceae were still highly susceptible to carbapenems .Overall less than 7 .0% of these strains were resistant to carbapenems .About 62 .8% and 59 .4% of Acinetobacter spp .(A .baumannii accounts for 89 .2% ) strains were resistant to imipenem and meropenem ,respectively .Compared with the data of year 2012 , extensively-drug resistant strains in K . pneumoniae and A . baumannii decreased .Conclusions The antibiotic resistance of clinical bacterial isolates is growing in 2013 .The disseminated multi-drug or pan-drug resistant strains in a special region poses a serious threat to clinical practice and implies the importance of strengthening infection control .

OBJECTIVETo evaluate the frequency of the nucleophosmin (NPM1) gene and the CCAAT/enhancer binding protein α gene (CEBPA) through polymerase chain reaction (PCR) array in pediatric patients with cytogenetically normal acute myeloid leukemia (CN-AML) and explore the clinical significances of these mutations.

METHODBetween August 2009 and December 2012, 30 children (<16 years old) with newly diagnosed CN-AML were included. The clinical characteristics were analyzed in these patients. PCR combined with direct sequencing was used to detect NPM1, CEBPA gene mutations. All the data were statistically analyzed using SPSS17.0 software.

RESULTThe gene mutations were detected in each of the 30 patients. NPM1 mutation was positive in three patients (10%) with type A mutation, while CEBPA mutation was positive in two patients (6.7%) with double mutations (TAD, bZIP) . Besides, FLT3/ITD mutation was positive in three patients. Patients with NPM1 or FLT3/ITD had a significantly elevated diagnostic WBC count with a median diagnostic WBC count of 102.80×10(9)/L compared with 18.56×10(9)/L for the patients without mutations(t = 2.353, P = 0.043), as well as the marrow blast percentage (94.0% vs. 80.0%, t = 3.804, P = 0.002). The complete remission was achieved in all the 3 patients with NPM1 mutations and 2 patients with CEBPA mutations. All the patients with these mutations also achieved 2-year event-free survival (EFS) and 2-year overall survival (OS), while 2-year EFS and 2-year OS of the other patients were (40.1 ± 11.2)% and (51.8 ± 10.9)% (P = 0.044, 0.091, respectively).

CONCLUSIONNPM1 and CEBPA mutations may indicate a favorable prognosis in pediatric CN-AML.

Adolescent ; CCAAT-Enhancer-Binding Proteins ; genetics ; Child ; Child, Preschool ; DNA Mutational Analysis ; Disease-Free Survival ; Female ; Genotype ; Humans ; Infant ; Leukemia, Myeloid, Acute ; genetics ; mortality ; pathology ; Male ; Mutation ; Nuclear Proteins ; genetics ; Prognosis ; Retrospective Studies ; fms-Like Tyrosine Kinase 3 ; genetics

OBJECTIVETo explore the feasibility of detecting lymphoma with the application of BIOMED-2 standardized immunoglobulin/T cell receptor (IG/TCR) gene rearrangement system in formalin fixed paraffin-embedded (FFPE) tissue samples, and to discuss the relationship between the longest amplification fragment of extracted DNA and positive detection rate of different IGH V-J primers.

METHODSDNA was extracted from 50 cases of FFPE tissue samples. Multiplex-PCR amplifications were performed and then the IG/TCR gene rearrangements were analyzed using BIOMED-2 standardized clonality analysis system.

RESULTS(1)When the DNA concentration was diluted to 50-100 ng/μl from 100-500 ng/μl, the proportion of the longest amplification fragment (300-400 bp) of DNA was improved from 10.0% to 90.0% in 30 cases of diffuse large B cell lymphoma (DLBCL) wax roll samples (P<0.01). The positive rate of IGH+IGK was increased from 46.7% to 83.3%, the difference was statistically significant (P=0.006). The lengths of the longest amplification fragments of DNA were all longer than 300 bp in the paraffin section samples of DLBCL. The positive rate of IGH+IGK of these samples was 96.7%. The difference of the positive rate of IGH+IGK between the wax roll samples and the paraffin section samples had no statistical significance (P=0.195). (2)When the concentration of DNA was high, most of the longest amplification fragments of extracted DNA were 100 bp or 200 bp, and the detection rate of short fragment IGH FR3 was more stable than that of long fragment IGH FR1. (3)The clonality analysis of TCRG+TCRB in all 13 cases of peripheral T cell lymphoma samples showed positive results, while no positive IG/TCR clones were found in 7 cases of reactive lymphoid tissue hyperplasia in control group.

CONCLUSIONDilution of DNA is the only method to improve not only the proportion of longest fragment amplification but also the detection rate of clonality. The detection rate of IGH FR3 would not be affected by the concentration of DNA. The application of BIOMED-2 standardized IG/TCR gene rearrangement system in FFPE tissue samples plays an important role in the lymphoma diagnosis.

Gene Rearrangement, T-Lymphocyte ; Humans ; Lymphoma ; diagnosis ; genetics ; Paraffin Embedding ; V(D)J Recombination