ABSTRACT
There is a need for a specific, sensitive, and practical diagnostic test to monitor onchocerciasis elimination campaigns. In April 2001, an enzyme-linked immunosorbent assay (ELISA) using 3 recombinant antigens and a rapid-format antibody card test (immunochromatographic test; ICT) using an individual antigen were compared in a Mexican population with onchocerciasis. The sensitivity of the ELISA and ICT was 97% and 86%, respectively.
Subject(s)
Antigens, Helminth/blood , Onchocerca volvulus/isolation & purification , Onchocerciasis/diagnosis , Adolescent , Adult , Aged , Animals , Child , Child, Preschool , Enzyme-Linked Immunosorbent Assay/methods , Enzyme-Linked Immunosorbent Assay/standards , Female , Humans , Infant , Infant, Newborn , Male , Middle Aged , Onchocerca volvulus/immunology , Sensitivity and Specificity , Seroepidemiologic StudiesABSTRACT
A simple and accurate method for determining the distribution of sizes of single cells and aggregates of Azotobacter vinelandii by image analysis has been developed. A staining procedure using methylene blue helps to enhance the contrast between aggregates and background without altering aggregate size distribution. Sample dilution affected the distribution of the population and therefore should be avoided. Mixing and aeration conditions during culture play an important role in the aggregation of A. vinelandii. Cells grown under mild mixing conditions (unbaffled flasks) presented a thick slime layer and formed aggregates of up to 35 microm of average equivalent diameter. In contrast, under strong agitation conditions (baffled flasks) practically no aggregates were formed throughout cultivation. The method described can be used for the characterization of aggregation of other microbial cultures.
