ABSTRACT
Soluble antigen (SA) from chlamydial elementary bodies (EBs) was extracted with N-lauroylsarcosine. The extracted SA composed of lipopolysaccharide (LPS) and proteins was compared with EBs using an enzyme-linked immunosorbent assay (ELISA). Patient sera from natural chlamydial infections exhibited ELISA mean absorbance (A(492) and A(405/650)) values 2-5 times higher with SA than with EBs, resulting in a better discrimination between positive and negative human sera.
Subject(s)
Antibodies, Bacterial/blood , Antigens, Bacterial/chemistry , Chlamydia Infections/diagnosis , Chlamydia trachomatis/immunology , Enzyme-Linked Immunosorbent Assay/methods , Lipopolysaccharides/chemistry , Sarcosine/analogs & derivatives , Adult , Blotting, Western , Chlamydia trachomatis/chemistry , Detergents/chemistry , Electrophoresis, Polyacrylamide Gel , Female , Humans , Male , Middle Aged , Sarcosine/chemistryABSTRACT
The influence of the number of passages in chick embryo yolk sac (EPs) on the properties of the lipopolysaccharide (LPS) and other antigens of Coxiella burnetii Priscilla strain in polyacrylamide gel electrophoresis in the presence of sodium dodecyl sulphate (SDS-PAGE), immunoblot analysis, enzyme-linked immunosorbent assay (ELISA) and complement-fixation reaction (CFR) test has been studied. Three phases in the phase variation of Coxiella burnetii could be distinguished by these methods: phase I lasting up to the 20th passage (EP 20), intermediate phase corresponding to EP 20-EP 70, and phase II beginning at EP 80. The changes in LPS were more marked than those in proteins which conserved their immunoblot profile up to EP 80. The phase II was clearly demonstrated by all the methods used.
