羊李氏杆菌病原特征、菌体鉴定和中西医防治

羊李氏杆菌病又称转圈病,是一种常见的食源性病原菌,主要发生在春秋交替季节,羔羊、成年羊均可感染发病,由于病死率较高,对羊群健康存在较大威胁。首先分析羊李氏杆菌病的病原特征,然后介绍羊李氏杆菌病的流行病学,羔羊及成年羊的临床症状和病理变化,并分析了羊李氏杆菌病的菌体鉴定和鉴别诊断方法,最后提出中西药治疗和预防措施,以期降低羊李氏杆菌病发病率,促进养羊业健康发展。

Optimization on Identification Standards and Artificial Inoculation Methods In Vitro on Resistance to Chrysanthemum White Rust

[Objective] This research aimed at exploring an effective way for inoculation and identification of chrysanthemum white rust under controlled conditions. [Method] By combining the observation methods with the naked eye and under optical microscope, we had established the identification standards for chrysanthemum white rust with six classifications and optimized artificial inoculation methods in vitro. [Result] The results showed that bottled cuttings identification method and petri dished leaves identification method both can be used for identification in vitro of chrysanthemum white rust, bottled cuttings identification method had shown better effects than petri dished leaves identification method, and was supposed to be best artificial inoculation and identification method in vitro. [Conclusion] This research had provided a scientific method for safe and effective researches on chrysanthemum white rust, in order to control the occurrence and diffusion of this quarantine disease.

Isolation and Characterization of Heterotrophic Nitrifying Strain W1

In a high concentration substrate medium, a heterotrophic bacterium with high removal efficiency of ammonium, named W1, was isolated from activated sludge of coking wastewater treatment facility. The bacterium was Gram-negative, rod-shaped, and identified preliminarily as Alcaligenes sp. according to its morphological and physiological properties and its 16S rRNA gene sequence analysis. In the high concentration ammonium medium (400 mg·L 1 4 NH -N), the effects of C source, N source, C/N ratio and initial pH of medium on ammonium removal were investigated in order to determine the optimal condition for strain W1. The maximum ammonium removal was around 95% in 4 days in an improved medium. The production of N 2 gas was examined in a closed system that was full of pure oxygen at the beginning. N 2 gas was detected in the system after 4 days of cultivation, which further testified that strain W1 has heterotrophic nitrification and aerobic denitrification abilities simultaneously.

Construction and quality identification of T7 recombination expression cDNA library form human lung cancer

Objective:Currently,only a limited numbers of tumor markers for non small lung cancer(NSCLC) diagnosis,new biomarker,such as serum autoantibodies may improve the early detection of lung cancer.Our objective is construction human lung squamous carcinoma and adenocarcinoma T7 phage display cDNA library from the tissues of NSCLC patients.Methods:mRNA was isolated from a pool of total RNA extract from NSCLC tissues obtained from 5 adenocarcinomas and 5 squamous carcinomas,and then mRNA was reverse transcribed into double stranded cDNA.After digestion,the cDNA was inserted into T7Select 10-3 vector.The phage display cDNA library was constructed by package reaction in vitro and plate proliferation.Plaque assay and PCR were used to evaluate the library.Results:Two T7 phage display cDNA library were established.Plaque assay show the titer of lung squamas carcinoma library was 1.8 × 106 pfu,and the adenocarcinoma library was 5 × 106 pfu.The phage titer of the amplified library were 3.2 × 1010 pfu/mL and 2.5 × 1010 pfu/mL.PCR amplifica-tion of random plaque show insert ratio were 100%(24/24) in adenocarcinoma library and 95.8% in human lung squamas carcinoma library(23/24).Insert range from 300 bp to 1 500 bp.Conclusion:Two phage display cDNA library from NSCLC were constructed.

Screening and characterization of a high taxol producing fungus by protoplast mutagenesis

The preparation, regeneration and mutagenesis of the taxol-producing fungus UV40-19 protoplasts were discussed in the experiment. Totally 42 strains displayed hygromycin resistance. Six strains were found to be positive mutants when screened on plate containing 90μg/mL hygromycin. One hereditarily stable strain UN05-6 was obtained, which raised the taxol yield from （376.38 ± 8.41）μg/L to （493.12 ±11.36） μg/L. The optimal conditions for the preparation, regeneration and mutagenesis of the taxol producing fungus UV40-19 were as follows： 1 ）enzymolysis in a solution containing 3% lywallzyme, 4% snailase, 1% lysozyme and 3% cellulose at 30~C water bath, pH5.5 - 6.0 for 5h; 2） The prepared protoplasts were regenerated by using bilayer plate culturing method; 3）To mutagenize the fungus UV40-19, the protoplast suspension was treated with 0.8mg/mL NTG for 15min, followed by UV irradiation （30W, 30cm distance）for 40s under magnetic stirring. The purified products of the fungus UN05-6 fermented extracts have significant inhibitive effects on SMMC-7721 cell.

Identification of Pathogenic Germs and Antibiotics Residues in the Raw Milk and Their Effects on Human Health

Milk is a food of great value, it provides more essential nutrient than any other natural food. The presence of pathogenic bacteria and antibiotic residues in milk can cause a real danger to consumers. Effectively, the milk consumption contaminated by bacteria can have an immediate impact which means a toxi-infection. Therefore, the presence of antibiotics residues in milk can constitute an important risk at the allergic and antibiotic resistance cases on the consumer. The present study concerning the pathogens germs identification and Antibiotic residues seeking in milk and their impact on the human health, has been realized on a total number of 80 samples of raw milk resulted from direct sale channel （dairies） throughout Blida different regions localities. The Microbiological analysis has shown only three conform samples to JORA Standards. Really, milk non-conformity results to the microbiological standards consisting on total aerobic mesophilic flora total count, total coliforms, Thermotolerant coliforms E. coli, Faecal streptococcus, Staphylococcus aureus have shown the following contamination rate： 61.25%, 93.75%, 86.25%, 55%, 93.75% and 50%. Salmonella is characterized by a total absence in all analyzed milk samples. Moreover, the antibiotics residues research by Delvotest SP make plainly visible 33 positive samples. Further, two samples of the three which were judged conform to the bacteriology standards has been found contaminated by the antibiotic residues. The analyzed milk quality can be considered as a real danger to the consumption.