[Studies on spray of niclosamide ethanolamine salt II observation on prevention of Schistosoma japonicum infection in bovine].

OBJECTIVE: To investigate the spray of niclosamide ethanolamine salt on prevention of bovine schistosomiasis in the field so as to provide a technical support for the improvement of schistosomiasis control strategy. METHODS: A total of 160 buffalo were selected as experimental objects marked by ear-mark numbers. All the buffalo were administered with praziquantel and then randomly divided into 3 groups, which were sprayed with niclosamide ethanolamine salt (500 ml per head) every 15 d (Group A), every 30 d (Group B) and an agent without niclosamide ethanolamine salt every 15 d (Group C as the control), respectively. The buffalo's droppings were collected to examine the eggs of schistosome every 30 days during the trial. RESULTS: Ninety days after the spraying, the prevalence rates of schistosomiasis were 4.00%, 4.08%, and 24.49% in the Group A, Group B, and Group C, respectively. Compared with the control group (Group C), the decline prevalence rates of schistosomiasis were 83.67% and 83.34% in the Group A and Group B, respectively. CONCLUSIONS: The buffalo spraying with 1% niclosamide ethanolamine salt can reduce schistosomiasis prevalence in bovine, that is this intervention has an obvious protective effect.

Isolation of soluble proteins from an industrial strain Streptomyces avermitilis in complex culture medium for two-dimensional gel electrophoresis.

Two-dimensional gel electrophoresis (2-DE) is a core proteomic technique to study protein expression and function in living organisms. Although 2-DE has been extensively used for the investigation of bacteria, yeast, animal and plant tissue cells, the isolation of proteins from the organisms and elimination of salt, nucleotide, polysaccharide, lipids and other contaminations from the samples often limit its application. In this study, the protocol for protein isolation from cells of Streptomyces avermitilis cultivated in partially insoluble complex medium was investigated. The goal was to make the obtained extraction samples suitable for the two-dimensional electrophoresis, thus make the further proteome analysis possible. Compared to non-denatured procedure, the denatured one, precipitating with 10% TCA in acetone, efficiently eliminated the interference substances from the cell lysate. Thiourea in the rehydration solution enhanced the resolubilization of protein pellets but led to heavy horizontal streaking in the 2-DE gels. High protein loading amount improved the resolution of some low abundance proteins but did not adapt to the high abundance proteins. And it was also important to collect cells at appropriate culture time according to the analysis target. With the optimized protein extraction protocol, the protein expression patterns of S. avermitilis during the onset of avermectin production in complex medium were analyzed.