OBJECTIVE: To identify and analyze drug sensitivity of Corynebacterium glucuronolyticum iscolated from clinic, and to provide reference for clinical drug use. METHODS: Two strains isolated from the urine specimens of urolithiasis-induced urinary tract infection patients in our hospital were inoculated into Columbia blood plate and the MacConkey plate. The growth of strains was observed and counted. Protein mass spectrometry of strains was detected by MALDI-TOF-MS. DNA of strains was extracted, and PCR was used to amplify the 16S ribosome RNA (rRNA) sequence. Bi-directional sequencing of 1 500 bp target bands was conducted. Blast comparison between it and GenBank database was conducted to identify bacterial strain. Drug resistance of 2 strains was monitored by Etest assay. RESULTS: Two strains grew on the Columbia blood plate (with colony forming unit ＞105 CFU/mL) and did not grow on the MacConkey plate. Two strains were Gram-positive Corynebacterium and showed palisading or eight type arrangement. Two strains were C. glucuronolyticum by MALDI-TOF-MS identification, with reliability of 99. 9％. The characteristic peaks of m/z 2 431, 3 089, 3 364, 3 378, 4 200, 5 508, 6 302, 6 637, 6 730, 6 946, 12 603 appeared. Blast comparison showed that the sequence homology of 2 strains compared with C. glucuronolyticum strain known in GenBank were higher than 98 ％. Results of drug sensitivity test showed that strain 1 was resistant to ceftriaxone and ciprofloxacin, and sensitive to 14 other antibiotics as penicillin G; strain 2 was resistant to ceftriaxone, erythromycin, ciprofloxacin, tetracycline and clindamycin, moderately sensitive to cefotaxime, and sensitive to 10 other antibiotics. CONCLUSIONS: Two strains are C. glucuronolyticum, and drug resistance of them to commonly used antibiotics is different. The strains are rare pathogen of urinary tract and show multidrug resistance. Antibiotics should be selected according to the results of strain identification and drug sensitivity test.

Objective:To construct recombinant influenza viruses expressing Gaussia luciferase (Gluc) with different influenza virus backbones and analyze their growth characteristics, genetic stability, ability to express Gluc and in vitro anti-influenza drug activity. Methods:The C-terminal of PR8NA was modified by inserting the porcine teschovirus-2A autocleavage peptide (P2A) and the Gluc-coding gene. Recombinant viruses, PR8NAGluc/PR8 and PR8NAGluc/WSN, were rescued using the eight-plasmid system of influenza virus reverse genetics, with seven plasmids derived from A/Puerto Rico/8/34(PR8) (H1N1) and A/WSN/1933 (WSN) H1N1. The genetic stability of the recombinant viruses was verified by RT-PCR. The fluorescence activity and the growth kinetics of the two recombinant viruses were compared. The correlation between the fluorescence activity of PR8NAGluc/WSN and median tissue culture infective dose (TCID 50), and the anti-drug activity of PR8NAGluc/WSN against oseltamivir, favipiravir, and Lianhua Qingwen in vitro were also analyzed. Results:The Gluc-expressing recombinant viruses constructed using PR8 and WSN backbones were successfully rescued by reverse genetics. Compared with the PR8 backbone, the WSN backbone significantly improved the fluorescence activity of Gluc. Moreover, the PR8NAGluc/WSN virus expressed stably in embryonated egg, and its replication kinetics was slightly lower than that of wild type. The fluorescence activity of PR8NAGluc/WSN virus had a good correlation with its TCID 50. The PR8NAGluc/WSN virus was sensitive to oseltamivir, favipiravir and Lianhua Qingwen. Conclusions:The recombinant virus with a WSN backbone exhibited higher fluorescence expression intensity as compared with the recombinant virus with a PR8 backbone. This study provided reference for high-throughput screening of anti-influenza drugs and the development of influenza virus vector vaccines.

OBJECTIVE To investigate the effect and mechanism of acute exposure to sodium cyanide(NaCN)on brain nerve damage induced by closed hypoxia in mice.METHODS ① Mice were randomly divided into hypoxia+NaCN 0(hypoxia control group),2.56,3.8,and 5.1 mg·kg-1 groups.After ip adminis-tration of different concentrations of NaCN,the mice were immediately placed into a closed hypoxic tank and the hypoxia survival time was observed.②Mice were divided into normal control,NaCN 3.8 mg·kg-1,hypoxia(30 and 60 min)and NaCN 3.8 mg·kg-1+hypoxia(30 and 60 min)groups.After grouping,the pH,oxygen saturation(sO2),oxygen tension(pO2)and carbon dioxide partial pressure(pCO2)of arterial blood of mice were detected using an arterial blood gas analyzer.The cortical cerebral blood flow of mice was detected using a laser speckle imager.The dry and wet brain tissue were weighed separately,and the brain moisture content was calculated.The kit was used to detect the activity of total superoxide dismutase(T-SOD)and the content of malondialdehyde(MDA)in the hippocampus.TUNEL staining was used to detect the apoptosis rate of cells in the hippocampus.HE staining was used to detect path-ological changes in the hippocampus.RESULTS ①Compared with the hypoxic control group,the sur-vival time of mice in the hypoxic+NaCN groups was significantly prolonged(P<0.01).②Compared with the normal control group,the hypoxia 30 min group showed upregulation of arterial blood p CO2(P<0.05),downregulation of p O2(P<0.05).The hypoxia 60 min group showed upregulation of arterial blood p CO2(P<0.05)and downregulation of cortical cerebral blood flow(P<0.05).In the NaCN 3.8 mg·kg-1 group,arterial blood p O2 and s O2 were significantly downregulated(P<0.05),so was cortical cerebral blood flow(P<0.01),but MDA content and T-SOD activity were significantly upregulated(P<0.01),and the brain moisture content was increased(P<0.01).Compared with the hypoxia 30 min group,s O2 and p O2 of arterial blood in the NaCN+hypoxia 30 min group were significantly upregulated(P<0.05),while p CO2 was significantly downregulated(P<0.05).Compared with the hypoxia group at corresponding time points,the NaCN+hypoxia 30 or 60 min groups showed significant downregulation of cerebral blood flow(P<0.01),significant upregulation of MDA content and T-SOD activity(P<0.01),and signifi-cant upregulation of brain moisture content(P<0.01).HE staining results showed that the NaCN 3.8 mg·kg-1 group and the NaCN+hypoxia group(30 or 60 min)showed significant cell swelling and vacuolization in cells in the hippocampal tissue,a decrease in the number of neurons,nuclear pyknosis and deep staining.TUNEL fluorescence results showed that the NaCN 3.8 mg·kg-1 group significantly increased the apop-tosis rate of the mouse hippocampus compared with the normal control group(P<0.05).The NaCN+ hypoxia 30 and 60 min groups significantly increased the apoptosis rate of the mouse hippocampus compared with the hypoxia group at corresponding time points(P<0.05).CONCLUSION NaCN can exacerbate hypoxia induced decrease in cerebral blood flow,oxidative stress in brain tissue,and neuro-nal apoptosis in mice,thereby reducing oxygen consumption in closed hypoxic tanks and prolonging their survival time.The mechanism is related to reduced utility of cell oxygen,delaying CO2 accumulation and increasing free oxygen in vivo.

Lipid Droplets/metabolism* ; Bacteria ; Lipid Metabolism