Bacterin was prepared by formalin-inactivating the virulent strain of Vibrio hollisae isolated from diseased Seriola dumerili （amberjack） suffering from vibriosis. Healthy S. dumeriIi were vaccinated by respective p...Bacterin was prepared by formalin-inactivating the virulent strain of Vibrio hollisae isolated from diseased Seriola dumerili （amberjack） suffering from vibriosis. Healthy S. dumeriIi were vaccinated by respective procedures of intramuscular injection, immersion, and orally administration. Results of the three different vaccinations were compared. Blood was drawn from the vaccinated fish every 7 days, and the antibody titers and lysozyme activities of the sera were determined. The antibody titer of injected fish was 1：40 at 7 d, and reached its peak of 1：320 at 28 d, while the fish vaccinated by immersion and orally administration exhibited weak antibody responses, the antibody titres of 〈1：10, 1：20, 1：160 were observed at 7 d, 14 d, 35 d respectively. Compared with the control, the vaccinated fish exhibited significantly higher lysozyme activities （P〈0.05）. Upon challenge with virulent strain, the relative percent survival （RPS） of injected, immersed and oral administrated fish were 75%, 45%, and 40% respectively, and the injected fish showed significantly higher RPS than immersed and oral administrated fish. The results suggested that vaccination of S. dumerili by the injection would be the best strategy to prevent the vibriosis in S. dumerili farm.展开更多
AIM: To develop an oral attenuated Salmonella typhimurium vaccine against gastric cancer and to evaluate its efficacy in mice. METHODS: A complementary sequence of Nco Ⅰ site and a sequence coding for MG7-Ag mimotope...AIM: To develop an oral attenuated Salmonella typhimurium vaccine against gastric cancer and to evaluate its efficacy in mice. METHODS: A complementary sequence of Nco Ⅰ site and a sequence coding for MG7-Ag mimotope were designed at the 5'terminus of forward primer. Using p1.2 Ⅱ-HBCAg plasmid as template, PCR was performed to get a fusion gene of the mimotope and a HBcAg gene. The fusion gene was then subcloned into the plasmid pYA3341 complementary to Salmonella typhimurium X4550, and the recombinant plasmid was then transformed into attenuated Salmonella typhimurium X4550. Balb/c mice were orally immunized with the recombinant Salmonella typhimurium X4550. The mice were immunized every 2 wk to reinforce the immunity. At the 6th wk, serum titer of antibody was detected by ELISA, and at the 8th wk, cellular immunity was detected by 51Cr release test. Ehrlich ascites carcinoma cells expressing MG7-Ag were used in tumor challenge assay as a model to evaluate the protective effect of the vaccine. RESULTS: Serum titer of antibody against MG7-Ag was significantly higher in mice immunized with the vaccine than in control groups (0.9538±0.043 vs 0.6531±0.018, P<0.01; 0.9538±0.043 vs 0.6915±0.012, P<0.01), while in vitro 51Cr release assay of the splenocytes showed no statistical difference in the three groups. Two weeks after tumor challenge, 1 in 5 immunized mice was tumor free, while all the mice in the control group presented tumor. CONCLUSION: Oral attenuated Salmonella typhimurium vaccine against the MG7-Ag mimotope of gastric cancer is immunogenic. It can induce significant humoral immunity against tumors in mice, and has some protective effects.展开更多
The characteristics of a bacterium strain M3, isolated from cultured flounder Paralichthys olivaceus with remarkable external sign of skin ulcer during an epizootic outbreak, indicated that the bacterium belonged to t...The characteristics of a bacterium strain M3, isolated from cultured flounder Paralichthys olivaceus with remarkable external sign of skin ulcer during an epizootic outbreak, indicated that the bacterium belonged to the species Vibrio anguillarum . Challenge by I.M. (intramuscular injection), bath, and oral administration with M3 showed that it was highly pathogenic for Paralichthys olivacues . The LD 50 dose was 5.144×10 3 CFU/ per fish infection by I.M. injection. Recovered inoculated bacteria from the surviving fish revealed that the asymptomatic carriers could be a latent contagious source. Study of the effect of bacterial culture CFS (cell free supernatant) showed that the exotoxins produced by M3 play an important role in its pathogenicity for flounder. The resistance of M3 to 36 out of 41 antibiotics indicated that the bacterial disease outbreak was mainly attributable to the frequent and excessive use of antimicrobial agents; and that vaccination would be an effective precaution against bacterial disease.展开更多
The aim of this study is to express the receptor-binding domain of Bacillus anthracis protective antigen in E.coli . Signal sequence of the outer membrane protein A (OmpA) of E.coli was attached to the 5′ end of the ...The aim of this study is to express the receptor-binding domain of Bacillus anthracis protective antigen in E.coli . Signal sequence of the outer membrane protein A (OmpA) of E.coli was attached to the 5′ end of the gene encoding protective antigen receptor-binding domain (the 4 th domain of PA, PAD4). The plasmid carrying the fusion gene was then transformed into E.coli and induced to express recombinant PAD4 by IPTG. The recombinant protein was purified by chromatography and then identified by N-terminal sequencing and Western blot. The recombinant protein, about 10% of the total bacterial protein in volume, was secreted to the periplasmic space of the cell. After a purification procedure including ion-exchange chromatography and gel filtration, about 10 mg of homogenous recombinant PAD4 was obtained from 1 L culture. Data from N-terminal sequencing suggested that the amino acid sequence of recombinant PAD4 was identical with its natural counterpart. And the result of Western blot showed the recombinant protein could bind with anti-PA serum from rabbit. High level secreted expression of PAD4 was obtained in E.coli . The results reported here are parts of a continuing research to evaluate PAD4 as a potential drug for anthrax therapy or a candidate of new vaccine.展开更多
Infection with Brucella causes brucellosis, a chronic disease in humans, which induces abortion and sterility in livestock. Among the different Brucella species, Brucella melitensis is considered the most virulent and...Infection with Brucella causes brucellosis, a chronic disease in humans, which induces abortion and sterility in livestock. Among the different Brucella species, Brucella melitensis is considered the most virulent and is the predominant species associated with outbreaks in China. To date, no safe human vaccine is available against Brucella infection. The currently used live vaccines against Brucella in livestock induce antibodies that interfere with the diagnosis of field infection in vaccinated ani- mals, which is harmful to eradication programs. However, there is as yet no complete profile of immunogenic proteins of B. melitensis. Towards the development of a safer, equally efficacious, and field infection-distinguishable vaccine, we used immunoproteomics to identify novel candidate immunogenic proteins from B. melitensis M5. Eighty-eight immunoreactive protein spots from B. melitensis M5 were identified by Western blotting and were assigned to sixty-one proteins by mass spectrometry, including many new immunoreactive proteins such as elongation factor G, FOFI ATP synthase subunit beta, and OMPI. These provide many candidate immunoreactive proteins for vaccine development.展开更多
基金Supported by NSFC (No. B9910030)Key Technologies Program of Fujian Province (No. 2000z080)
文摘Bacterin was prepared by formalin-inactivating the virulent strain of Vibrio hollisae isolated from diseased Seriola dumerili （amberjack） suffering from vibriosis. Healthy S. dumeriIi were vaccinated by respective procedures of intramuscular injection, immersion, and orally administration. Results of the three different vaccinations were compared. Blood was drawn from the vaccinated fish every 7 days, and the antibody titers and lysozyme activities of the sera were determined. The antibody titer of injected fish was 1：40 at 7 d, and reached its peak of 1：320 at 28 d, while the fish vaccinated by immersion and orally administration exhibited weak antibody responses, the antibody titres of 〈1：10, 1：20, 1：160 were observed at 7 d, 14 d, 35 d respectively. Compared with the control, the vaccinated fish exhibited significantly higher lysozyme activities （P〈0.05）. Upon challenge with virulent strain, the relative percent survival （RPS） of injected, immersed and oral administrated fish were 75%, 45%, and 40% respectively, and the injected fish showed significantly higher RPS than immersed and oral administrated fish. The results suggested that vaccination of S. dumerili by the injection would be the best strategy to prevent the vibriosis in S. dumerili farm.
基金Supported by the National Natural Science Foundation of China, No. 39870742
文摘AIM: To develop an oral attenuated Salmonella typhimurium vaccine against gastric cancer and to evaluate its efficacy in mice. METHODS: A complementary sequence of Nco Ⅰ site and a sequence coding for MG7-Ag mimotope were designed at the 5'terminus of forward primer. Using p1.2 Ⅱ-HBCAg plasmid as template, PCR was performed to get a fusion gene of the mimotope and a HBcAg gene. The fusion gene was then subcloned into the plasmid pYA3341 complementary to Salmonella typhimurium X4550, and the recombinant plasmid was then transformed into attenuated Salmonella typhimurium X4550. Balb/c mice were orally immunized with the recombinant Salmonella typhimurium X4550. The mice were immunized every 2 wk to reinforce the immunity. At the 6th wk, serum titer of antibody was detected by ELISA, and at the 8th wk, cellular immunity was detected by 51Cr release test. Ehrlich ascites carcinoma cells expressing MG7-Ag were used in tumor challenge assay as a model to evaluate the protective effect of the vaccine. RESULTS: Serum titer of antibody against MG7-Ag was significantly higher in mice immunized with the vaccine than in control groups (0.9538±0.043 vs 0.6531±0.018, P<0.01; 0.9538±0.043 vs 0.6915±0.012, P<0.01), while in vitro 51Cr release assay of the splenocytes showed no statistical difference in the three groups. Two weeks after tumor challenge, 1 in 5 immunized mice was tumor free, while all the mice in the control group presented tumor. CONCLUSION: Oral attenuated Salmonella typhimurium vaccine against the MG7-Ag mimotope of gastric cancer is immunogenic. It can induce significant humoral immunity against tumors in mice, and has some protective effects.
文摘The characteristics of a bacterium strain M3, isolated from cultured flounder Paralichthys olivaceus with remarkable external sign of skin ulcer during an epizootic outbreak, indicated that the bacterium belonged to the species Vibrio anguillarum . Challenge by I.M. (intramuscular injection), bath, and oral administration with M3 showed that it was highly pathogenic for Paralichthys olivacues . The LD 50 dose was 5.144×10 3 CFU/ per fish infection by I.M. injection. Recovered inoculated bacteria from the surviving fish revealed that the asymptomatic carriers could be a latent contagious source. Study of the effect of bacterial culture CFS (cell free supernatant) showed that the exotoxins produced by M3 play an important role in its pathogenicity for flounder. The resistance of M3 to 36 out of 41 antibiotics indicated that the bacterial disease outbreak was mainly attributable to the frequent and excessive use of antimicrobial agents; and that vaccination would be an effective precaution against bacterial disease.
文摘The aim of this study is to express the receptor-binding domain of Bacillus anthracis protective antigen in E.coli . Signal sequence of the outer membrane protein A (OmpA) of E.coli was attached to the 5′ end of the gene encoding protective antigen receptor-binding domain (the 4 th domain of PA, PAD4). The plasmid carrying the fusion gene was then transformed into E.coli and induced to express recombinant PAD4 by IPTG. The recombinant protein was purified by chromatography and then identified by N-terminal sequencing and Western blot. The recombinant protein, about 10% of the total bacterial protein in volume, was secreted to the periplasmic space of the cell. After a purification procedure including ion-exchange chromatography and gel filtration, about 10 mg of homogenous recombinant PAD4 was obtained from 1 L culture. Data from N-terminal sequencing suggested that the amino acid sequence of recombinant PAD4 was identical with its natural counterpart. And the result of Western blot showed the recombinant protein could bind with anti-PA serum from rabbit. High level secreted expression of PAD4 was obtained in E.coli . The results reported here are parts of a continuing research to evaluate PAD4 as a potential drug for anthrax therapy or a candidate of new vaccine.
基金supported by the National Basic Research Program of China (Grant No. 2010CB530200)
文摘Infection with Brucella causes brucellosis, a chronic disease in humans, which induces abortion and sterility in livestock. Among the different Brucella species, Brucella melitensis is considered the most virulent and is the predominant species associated with outbreaks in China. To date, no safe human vaccine is available against Brucella infection. The currently used live vaccines against Brucella in livestock induce antibodies that interfere with the diagnosis of field infection in vaccinated ani- mals, which is harmful to eradication programs. However, there is as yet no complete profile of immunogenic proteins of B. melitensis. Towards the development of a safer, equally efficacious, and field infection-distinguishable vaccine, we used immunoproteomics to identify novel candidate immunogenic proteins from B. melitensis M5. Eighty-eight immunoreactive protein spots from B. melitensis M5 were identified by Western blotting and were assigned to sixty-one proteins by mass spectrometry, including many new immunoreactive proteins such as elongation factor G, FOFI ATP synthase subunit beta, and OMPI. These provide many candidate immunoreactive proteins for vaccine development.
