Abstract: The present work assesses four factors to determine their influence on the viability of lyophilized Haemophilus influenzae strains and their -lactamase production: different suspension media, rehydration media, rehydration time and initial inoculum concentration. Three strains were obtained from inpatients from a state hospital, one of which was a -lactamase producing (TEM-1) strain. H. influenzae ATCC 10211 and ATCC 35056 were used as control strains for the culture medium and -lactamase production respectively. The media assayed were: 1) Brain Heart Infusion broth (BHI) was used as suspension medium with or without supplement of 6% lactose (BHI+L) or 10% sucrose (BHI+S), both cryo-protective agents, and 2) 10% skim milk with addition of 5% glutamate (SM+G). Different types of rehydration agents were assayed: BHI, BHI+L, BHI+S, water (H2O) and physiological solution (PS). Furthermore, different rehydration times were assayed (0-12 h), as well as the initial cell concentration (1016 to 102 CFU/ml). Highest viability of lyophilized H.influenzae strains was obtained with initial cell concentrations 1016 CFU/ml (45%?0.10), in BHI supplemented with cryoprotective agents: BHI+L (51%?0.02) or BHI+S (45.5%?0,10), rehydration with water (61%?0.09) at room temperature for 15 min (59.9%?0.47). Enzyme activity was not modified in any of the cases.
Olga Aulet de Saab , Olga Aulet de Saab and Marta Cecilia de Castillo , 2004. Assessment of Four Factors That Affect Viability of Lyophilized Haemophilus influenzae Strains . Asian Journal of Information Technology, 3: 1008-1012.