Objecflve To evaluate the performance of two rapid and low-cost metheds(MTT test,and rosazurin mierotitre assay)for the detection of resistance to first-line drugs in Mycobacterium tuberculosis.Methods sixty-four Myeobaeterium tuberculosis clinical isohtes were tested by the MTT test and the rosazuxin microtitre assay(REMA)respectively,and the results were compared with those obtained with the absolute concentration method on L(o)wenstein Jensen medium.Results The MTT test and the resazurin microtitre assay showed a good agreement compared with the absolute concentration method for all first-line drugs tested.The sensitibity,specificity and accuracy of the MTT test were 94.8%,96.0%,95.3%,for RFP;93.8%,93.8%,93.8% for INH;92.9%,96.O%,95.3% for EMB,90.6%,87.5%,89.1% for SM,respectively.The sensitivity,specificity and accuracy of the resazurin microtitre assay were 92.3%,96.0%,93.8%,for RFP;90.6%,90.6%,90.6% for INH;92.9%,94.0%,93.8% for EMB,87.5%,87.5%,87.5% for SM,respectively.The Kappa value of the MTT test and the absolute concentration method for the detection of resistance to RFP,INH,EMB,SM were 0.857,0.831,0.714,0.792.respeedvely;The Kappa value of the regazurin mierotitre assay and the absolute concentration method for the detection of resistance to RFP,INH,EMB,SM were 0.871,0.826,0.826,0.750,respectively.The Kappa value of the MTT test and the resazurin microtitre assay for the detection of resistance to RFP,INH,EMB,SM wefe 0.889,0.875.0.787,0.844,respectively.Conclusions Both MTT test and the resazurin microtitre assays are simple,rapid,low-cost and sensitive for rapid detection of resistance to first-line drugs.They could be promising methods for susceptibility assay of the first-line antituberculosis drugs in low-resource countries.

Objective·To construct recombinant mycobacteriophage TM4-RpfE to lay a foundation for experimental research about how to eradicate Mycobacterium tuberculosis in combination with anti-tuberculosis drugs,and how to shorten treatment for tuberculosis ultimately.Methods·Electrotransformation was used to introduce pJV53 plasmid into Mycobacterium smegmatis to prepare recombinant engineering bacteria.After amplification of hsp60-RpfE fusion gene by overlap PCR,a long gene fragment (homologous +hsp60-RpfE+homologous,HHRH) was amplified by multi-step overlap PCR.The DNA of mycobaeteriophage TM4 and HHRH fragment were cotransfected into the recombinant engineering bacteria by electrotransformation,then the recombinant phage from the single primary plaques were confirmed by PCR and sequencing.SDS-PAGE was used to analyze the protein expression in recombinant phage.Results·The hsp60-RpfE fusion gene at the length of 901 bp and HHRH fragment at the length of 1 873 bp were identified by overlap PCR.The PCR product produced 955 bp and 301 bp DNA bands in the first generation plaques colony.SDS-PAGE analysis showed a specific protein band at 21 000 in the recombinant phages.Conclusion·The recombinant mycobacterium phage TM4-RpfE was successfully constructed and the expression of target gene RpfE was initially verified.

Objective To describe a case of lower limbs infection of Helcococcus Kunzii in North China University of Science and Technology Affiliated Hospital in October 2017 and to analyze the etiology and drug susceptibility??Methods The bacteria were identified by French Meriere mass spectrometer and BD Phoenix?100 automatic bacterial identification／drug sensitivity system??The drug resistance of the bacteria was detected by disk diffusion method,and collected the clinical information and related literature information of the Helcococcus Kunzi to analyze??Results The Gram?positive cocci was isolated from the foot secretion of a patient with venous thrombosis of lower limbs complicated with infection??The result of smear was Gram?positive cocci in double,agglomerate and varied in size??On the blood plate,there was a small colony of α hemolysis??Thixozyme negative,β galactosidase negative??The results of mass spectrometry identification and two kinds of fully automatic bacterial identification ／ drug sensitivity system were identified as Helcococcus Kunzii,the isolates was resistant to erythromycin and clindamycin among the 10 antibiotics tested??By searching,sorting out and analyzing the literature information, it is revealed that the infection of this bacterium is not related to sex??Middle?aged and elderly people are mostly infected??And the cocci easily infected patients with lower immunity??The infection of lower limbs is 47??37%,the infection of blood flow is 15??79% and the other ways of infection are 42??11%( lung, mammary gland, etc??)??Conclusion Helcococcus Kunzii is a conditional pathogen, and patients with lower immunity are more common??Erythromycin resistance could identify it from the green balloon bacteria??Moreover, the bacteria could cause a wide spectrum of diseases,and easily cause sepsis and lower limbs infections,which reminds us that we should be vigilant in clinical practice??

To study the carriage status of drug susceptibility, clonal complex groups, serotypes, surface proteins and virulence genes of Streptococcus agalactiae from respiratory specimen sources. A total of 35 strains of S.agalactiae meeting the criteria were collected from 3 hospitals in 2 locations, Tangshan and Jinan. The age span of the patients was 3 days-92 years, and the percentage of elderly patients≥60 years was 71.5%.The susceptibility to 9 antimicrobial drugs was measured and analyzed using the micro broth dilution method. The strains were 100.0% sensitive to penicillin, linezolid, vancomycin, and ceftriaxone; However, it exhibits high resistance rates to erythromycin, clindamycin and levofloxacin, at 97.1%, 85.7% and 82.9% respectively; and the resistance rates to tetracycline and chloramphenicol were 34.3% and 14.2%, respectively. Genome sequence determination and analysis showed that 16 resistance genes were detected in 35 strains, among which: macrolide and lincosamide resistance genes were mainly ermB, with a carrying rate of 74.2%; tetracycline resistance genes were mainly tetM, with a carrying rate of 25.7%; in addition, the mutation rates of the quinolone resistance determinants gyrA and parC were 88.5% and 85.7%, respectively. 35 strains belonged to 6 ST types and 4 clonal groups, with CC10/ST10 as the main one, accounting for 62.8%; they contained 4 serotypes of Ⅰb, Ⅱ, Ⅲ, and Ⅴ, as well as 1 untyped strain, with serotype Ⅰb as the main one, accounting for 65.7%. The strains carried three pilus types, PI1+PI2a, PI2a and PI2b types, respectively, and detected five surface proteins, alpha, alp1, rib, srr, and r df_0594, and seven virulence factors, cba, cfb, cylE, fbsA, hylB, l mb, and pavA. Overall, S.agalactiae isolated from respiratory tract specimens is predominantly sourced from elderly patients, with CC10 strains being most prevalent. These strains harbor multiple drug-resistant and virulence genes, demonstrating elevated resistance rates to macrolides, lincosamides, and quinolones. This emphasizes the necessity for vigilant attention to the health threat posed by S. agalactiae from respiratory tract speciments of elderly patients.

Objective To screen the specific cytokines of tuberculous pleural effusion(plTB)by using liquid array technique to establish a diagnostic model and discuss its application value.Methods A total of 86 patients with plTB(plTB group)were included,including 41 patients in the confirmed plTB group and 45 patients in the clinically diagnosed plTB group.There were 42 other patients with pleural effusion in the control group.Seventeen cytokines in pleural effusion were analyzed by liquid array technology.Interleukin(IL)-1β,IL-2,IL-4,IL-5,IL-6,IL-8,IL-9,IL-10,gamma-interferon-induced protein 10(IP-10),IL-15,IL-17F,IL-27,tumor necrosis factor(TNF)-α,monocyte chemotactic protein-1(MCP-1),the expression levels of macrophage inflammatory protein-3a(MIP-3α),macrophage colony-stimulating factor(M-CSF)and β-interferon(IFN-β)were detected.Difference factors between the confirmed plTB group and the control group were screened,and the receiver operating characteristic(ROC)curve was drawn in the confirmed plTB patients.IP-10,IL-27 and MCP-1 with AUC>0.850 and specificity>80%were combined to diagnose plTB,and were compared with adenylate deaminase(ADA)and T-SPOT.TB in pleural effusion to evaluate the diagnostic efficacy.Results The levels of IL-2,IP-10,IL-27,TNF-α and MCP-1 were higher in the confirmed plTB group than those in the control group(P＜0.05).The sensitivity and specificity of IP-10,IL-27 and MCP-1 in the diagnosis of plTB were 87.8%and 81.0%.The sensitivity of three-factor combined diagnosis in 45 patients with plTB was still as high as 86.7%,and there was no significant difference in sensitivity compared with that in the diagnosed plTB group(P＞0.05).In the plTB group,the sensitivity of IP-10,IL-27 and MCP-1 combined detection was 87.2%,which was higher than that of T-SPOT.TB(81.4%)and ADA(54.7%).Conclusion The application of liquid array technology to the joint detection of pleural effusion IP-10,IL-27 and MCP-1 can provide help for the diagnosis of plTB.

To study the carriage status of drug susceptibility, clonal complex groups, serotypes, surface proteins and virulence genes of Streptococcus agalactiae from respiratory specimen sources. A total of 35 strains of S.agalactiae meeting the criteria were collected from 3 hospitals in 2 locations, Tangshan and Jinan. The age span of the patients was 3 days-92 years, and the percentage of elderly patients≥60 years was 71.5%.The susceptibility to 9 antimicrobial drugs was measured and analyzed using the micro broth dilution method. The strains were 100.0% sensitive to penicillin, linezolid, vancomycin, and ceftriaxone; However, it exhibits high resistance rates to erythromycin, clindamycin and levofloxacin, at 97.1%, 85.7% and 82.9% respectively; and the resistance rates to tetracycline and chloramphenicol were 34.3% and 14.2%, respectively. Genome sequence determination and analysis showed that 16 resistance genes were detected in 35 strains, among which: macrolide and lincosamide resistance genes were mainly ermB, with a carrying rate of 74.2%; tetracycline resistance genes were mainly tetM, with a carrying rate of 25.7%; in addition, the mutation rates of the quinolone resistance determinants gyrA and parC were 88.5% and 85.7%, respectively. 35 strains belonged to 6 ST types and 4 clonal groups, with CC10/ST10 as the main one, accounting for 62.8%; they contained 4 serotypes of Ⅰb, Ⅱ, Ⅲ, and Ⅴ, as well as 1 untyped strain, with serotype Ⅰb as the main one, accounting for 65.7%. The strains carried three pilus types, PI1+PI2a, PI2a and PI2b types, respectively, and detected five surface proteins, alpha, alp1, rib, srr, and r df_0594, and seven virulence factors, cba, cfb, cylE, fbsA, hylB, l mb, and pavA. Overall, S.agalactiae isolated from respiratory tract specimens is predominantly sourced from elderly patients, with CC10 strains being most prevalent. These strains harbor multiple drug-resistant and virulence genes, demonstrating elevated resistance rates to macrolides, lincosamides, and quinolones. This emphasizes the necessity for vigilant attention to the health threat posed by S. agalactiae from respiratory tract speciments of elderly patients.

Objective:To analyze the drug resistance characteristics of Klebsiella pneumoniae in the nasopharynx of hospitalized patients in North China from 2022 to 2023. Methods:From November 2022 to July 2023, nasopharyngeal swabs were collected from 100 inpatients in Affiliated Hospital of North China University of Science and Technology, and Klebsiella pneumoniae was isolated and cultured. At the same time, the clinical data of the patients were collected, including gender, age, department, clinical diagnosis of disease type, etc. The minimum inhibitory concentration of strains was detected by an automatic bacterial drug sensitivity system. The drug resistance genes, ST types, capsule serotypes and population structure of the strains were analyzed by whole genome sequencing and data analysis. Results:Klebsiella pneumoniae was isolated from 55 nasopharyngeal swabs of 100 inpatients(55.00%). Among the 55 inpatients with Klebsiella pneumoniae in the nasopharynx, 70.91% (39/55) were male, with an age distribution concentrated between 61 and 80 years old (58.18%, 32/55), and 50.91% (28/55) were in intensive care units (ICU). The main underlying disease type was nervous system disease (49.09%, 27/55). The results of drug sensitivity showed that the non-susceptibility rates of 55 strains of Klebsiella pneumoniae to cephalosporins, quinolones, aztreonam and nitrofurantoin were all more than 80.00%. Twenty-eight carbapenem-resistant Klebsiella pneumoniae strains (50.91%), 47 extended-spectrum β-lactamase producing strains (85.45%), and 48 multi-drug-resistant strains (87.27%) were detected. A total of 11 antibiotic resistance genes were detected, including carbapenems (carrying rate 76.36%) and extended-spectrum β-lactamase (carrying rate 96.36%). The 55 strains could be divided into 17 ST types, and the most common type was ST11 (25.45%). The 55 strains were divided into 18 capsular serotypes, among which K102 was the most prevalent (23.64%). OXA-1_ST307_K102 (21.82%) and KPC-2_ST5492_K125 (18.18%) were the dominant clones, distributed in the Department of Neurosurgery and ICU. The result of whole genome sequence analysis showed that there were four clusters with high homology among the 55 strains. The strains from the ICU formed two independent clusters, and strains from the Neurology ICU and Neurosurgery department formed one cluster respectively. Conclusion:The carrying rate of Klebsiella pneumoniae in the nasopharynx of inpatients is high, and the drug resistance of the strains is serious. There are many types of drug-resistant genes.

Objective:To analyze the drug resistance characteristics of Klebsiella pneumoniae in the nasopharynx of hospitalized patients in North China from 2022 to 2023. Methods:From November 2022 to July 2023, nasopharyngeal swabs were collected from 100 inpatients in Affiliated Hospital of North China University of Science and Technology, and Klebsiella pneumoniae was isolated and cultured. At the same time, the clinical data of the patients were collected, including gender, age, department, clinical diagnosis of disease type, etc. The minimum inhibitory concentration of strains was detected by an automatic bacterial drug sensitivity system. The drug resistance genes, ST types, capsule serotypes and population structure of the strains were analyzed by whole genome sequencing and data analysis. Results:Klebsiella pneumoniae was isolated from 55 nasopharyngeal swabs of 100 inpatients(55.00%). Among the 55 inpatients with Klebsiella pneumoniae in the nasopharynx, 70.91% (39/55) were male, with an age distribution concentrated between 61 and 80 years old (58.18%, 32/55), and 50.91% (28/55) were in intensive care units (ICU). The main underlying disease type was nervous system disease (49.09%, 27/55). The results of drug sensitivity showed that the non-susceptibility rates of 55 strains of Klebsiella pneumoniae to cephalosporins, quinolones, aztreonam and nitrofurantoin were all more than 80.00%. Twenty-eight carbapenem-resistant Klebsiella pneumoniae strains (50.91%), 47 extended-spectrum β-lactamase producing strains (85.45%), and 48 multi-drug-resistant strains (87.27%) were detected. A total of 11 antibiotic resistance genes were detected, including carbapenems (carrying rate 76.36%) and extended-spectrum β-lactamase (carrying rate 96.36%). The 55 strains could be divided into 17 ST types, and the most common type was ST11 (25.45%). The 55 strains were divided into 18 capsular serotypes, among which K102 was the most prevalent (23.64%). OXA-1_ST307_K102 (21.82%) and KPC-2_ST5492_K125 (18.18%) were the dominant clones, distributed in the Department of Neurosurgery and ICU. The result of whole genome sequence analysis showed that there were four clusters with high homology among the 55 strains. The strains from the ICU formed two independent clusters, and strains from the Neurology ICU and Neurosurgery department formed one cluster respectively. Conclusion:The carrying rate of Klebsiella pneumoniae in the nasopharynx of inpatients is high, and the drug resistance of the strains is serious. There are many types of drug-resistant genes.

Objective:To explore the feasibility of U6 and Cel-miR-39 as reference genes for quantitative detection of microRNA (miRNA) in cerebrospinal fluid (CSF) of tuberculous meningitis (TBM), and validate the difference of miRNAs between tuberculous and viral meningitis (VM).Methods:The remaining CSF specimens after routine examination were collected in Beijing Chest Hospital of Capital Medical University. A total of 36 TBM and 34 VM patients were enrolled based on the information in the medical records. Total RNA were extracted from the CSF samples, and Taqman based real-time quantitative PCR (RT-CR) analysis were performed to determine the concentration of the miRNAs in CSF. GeNorm, NormFinder and Bestkeeper software were used for stability analysis of the two reference genes. 2 -ΔCt method was used to determine the relative gene expression. Accordance of repeated tests was analyzed by Pearson correlation test. Continuous variables were compared by the t-test. Results:Among the 70 samples, the average cycle threshold (Ct) value of U6 was 30.40±3.30, while the average Ct value of Cel-miR-39 was 21.49±0.70. The expression level of Cel-miR-39 was higher than that of U6. Correlation analysis showed good accordance of the repeated tests among the reference genes and target genes analysis in the randomly selected 10 samples ( r>0.931, P<0.001). Based on the analyses results of the three software, including GeNorm, NormFinder and Bestkeeper, Cel-miR-39 presented better stability in RT-PCR analysis and was more suitable as a reference gene for miRNA quantitative determination in CSF sample of TBM patients. The relative expression levels of the three target miRNAs were calculated using Cel-miR-39 as the reference gene, and miR-126-3p (1.13±0.41 vs 3.34±0.82, t=2.452, P=0.016), miR-130a-3p (0.56±0.10 vs 2.59±0.70, t=2.960, P=0.004) and miR-151a-3p (0.64±0.25 vs 2.11±0.33, t=3.536, P<0.001) were showed significant lower expression levels in CSF in TBM group than that in VM group. Conclusions:Cel-miR-39 can be used as a reference gene for quantitative detection of miRNAs in CSF of TBM patients. Significant differences were detected in expression level of miR-126-3p, miR-130a-3p and miR-151a-3p between TBM and VM group.