No abstract

This study was undertaken to determine the frequency of Legionella infection in a dental clinic setting. Serum samples from 270 dental clinic personnel were evaluated using an enzyme-linked immunosorbent assay to detect Legionella-specific IgM and IgG antibodies. The pooled-species whole-cell-antigen preparation used in these assays was derived from six Legionella pneumophila strains and one strain each from Legionella bozemanii and Legionella micdadei. Significant levels of IgG and IgM antibodies were found in 20% and 16%, respectively, of the samples. This compares with 8% and 10%, respectively, for a randomly selected non-clinical group from the region (P less than 0.005). Samples from clinic personnel with significant IgG titers (greater than 1:128) were also evaluated for activity to each of the eight single-species antigens, with the following results: L. pneumophila, 45% (combined six strains); L. micdadei, 37%; and L. bozemanii, 18%. Comparing individuals' "years spent in the clinic environment" with the incidence of significant antibody levels strongly suggests that the risk of Legionella infection increases proportionately with increased clinic exposure time (P less than 0.05). Analysis of these data implies that Legionella may be present in the dental clinic environment, thus creating an increased risk for clinical personnel or patients.

Enzymemodified acylated protein derivatives were prepared with succinic and acetic anhydrides from washed fish muscle and were evaluted for their functionality. The degree of acylation and of hydrolysis by bromelain was studied to determine how these variables affect functionality of the protein. The degree of acylation was determined by measuring available epsilon amino groups of lysine. Susceptibility to hydrolysis was determined by treating with bromelain at different ratios of bromelain to substrate. The functional properties studied were emulsifying activity, emulsifying capacity, gelation, water absorption, aeration, and foam stability. These functional properties increased until 43-59% of the free amino groups were acylated. Further acylation had no significant effect. Hydrolysis of the acylated protein slightly 16wered the emulsifying, gelation, and water absorption properties, but increased the aeration capacity of both the acetylated and succinylated proteins and the foam stability of the latter. The succinylated prdteins displayed functional properties similar to those of the acetylated proteins. Succinylated proteins, however, yielded functionality slightly but significantly superior to that of acetylated proteins. The performance of enzyme-modified acylated fish protein derivatives in food systems is also discussed.