Brucellosis 2003 proceedings - PHIDIAS

Poster Session
This study aimed to produce Brucella abortus strain S.19 vaccine in a safe and
effective form that meets the recognized international laboratories standards. And in
a lyophilized form that eases its distribution. This study also endeavored the use of
bioreactor in the mass production of S.19 vaccine in the Sudan. In this research the
factors that affect the viability of Brucella abortus S.19 vaccine were studied. The
temperatures 25ºC and were found of be optimum for the stability of the vaccine.
This indicates that vaccination under Sudan conditions where the temperature
ranges between 25-40ºC does not affect the viability of the vaccine up to 40 minutes,
which is the time advised for vaccination from this finding. All the cells were
destroyed when the vaccine was heated to 60ºC for 5 minutes. This concludes that
pasteurization and boiling of milk completely eliminate the hazard of the sheded
brucella S.19 cells in milk post vaccination. S.19 vaccine was highly susceptible to
the direct sun light and it lost about 53.1% of its viability within two hours of exposure
to direct diffuse day light. Where as using dark non-transparent bottle restored its
viability after the same time of exposure. This illustrates the importance of containing
the vaccine in dark protected bottles during vaccination in shiny hot season to ensure
the recommended viable cells per dose. The phosphate buffered saline and the
distilled water were found sufficient to restore the viability of the vaccine when they
were used in suspending the harvested cells where as viability of the cells was
adversely affected when normal saline was used for the same period of time. The
effect of four disinfectants on the viability of S.19 vaccine was studied. Viz.: formalin,
70-75% alcohol, 0.5% phenol and chlorophenol. Out of these formalin was found to
be the best with 100% lethality of the cells during the first ten minutes. Seventy
percent and 75% ethyl alcohol were also able to inactivate the cells, but to a lesser
degree compared to formalin. When 0.5% phenol solution and absolute chlorophenol
were used, only partial inactivation was observed. The vaccine was freeze-dried, and
the best cell-surviving rate was 99.4% after 11 months of storage in –20ºC when the
lyophilizing stabilizing stabilizer was used. And 98.7% when the serum-lactose
solution was used under the same conditions. When the PBS was used during
lyophilization, it did not protect the cells against the lyophilization effect. Also during
this study, the Brucella abortus S.19 vaccine was produced by bath method using
Göttingen bioreactor. The estimated number of doses per a single batch (two liters)
was 29,000 full dose. When the OIE reference lab checked the quality of the vaccine,
it met the international standard.
100- VARIATIONS IN THE LYSIS OF Brucella melitensis Rev 1 BY
BACTERIOPHAGES.
L. Hernández Andrade 1 , E. Díaz Aparicio 1 , F. Suárez Güemes 2 . (1) CENID-Microbiología, INIFAP,
México, D.F. (2) Facultad de Medicina Veterinaria y Zootecnia, UNAM, México D.F.
Brucella melitensis Rev 1 confers a high level of protection against virulent B.
melitensis in goats and ewes. The purpose of this work, was to report the variations
of strains from eight different production batches of B. melitensis Rev 1 vaccine.
Three B. melitensis and one B. abortus reference strains were used as controls. The
colonial phase of B. melitensis Rev 1 cultures were determined using the acriflavine
test and crystal violet stain. Phage sensitivity testing was done with phages Tbilisi
(Tb), Weybridge (Wb), Izatnager (Iz) and R/C, at routine test dilution 10 4 (RTD), they
were incubated at 37ºC in atmosphere with 10% CO 2 and later lysis was observed.
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Brucellosis 2003 International Research Conference