ABSTRACT
From 1990 to 1996, routine screening for whooping cough identified 399 patients with a calmodulin-dependent adenylate cyclase-positive test result and yielded 69 Bordetella pertussis isolates. None of the patients were fully vaccinated, and most were less than 6 months old. Analysis of total DNA by pulsed-field gel electrophoresis (PFGE) after XbaI, SpeI, or DraI macrorestriction yielded 19, 15, and 5 different patterns, respectively, whereas ribotyping failed to demonstrate any strain polymorphism. Discrimination among the isolates was improved by combining the PFGE profiles. Some patterns were more frequent, but the corresponding patients were not clearly epidemiologically related. The patterns for two strains obtained during a 3-month period from patients who were neighbors differed by the length of a single DNA fragment. These data strongly suggest that one type of isolate is widely spread throughout the world and is carried by individuals other than patients who develop a true illness.
Subject(s)
Bordetella pertussis/classification , Bordetella pertussis/genetics , Polymorphism, Genetic , Bacterial Typing Techniques , Bordetella pertussis/isolation & purification , Child , Child, Preschool , DNA Fingerprinting , DNA Restriction Enzymes , DNA, Bacterial/genetics , DNA, Bacterial/isolation & purification , Disease Outbreaks , Electrophoresis, Gel, Pulsed-Field , Female , France/epidemiology , Humans , Infant , Male , Molecular Epidemiology , Polymorphism, Restriction Fragment Length , Whooping Cough/epidemiology , Whooping Cough/microbiologyABSTRACT
Two enzyme-linked immunosorbent assays were developed for detection of staphylococcal exfoliative toxins A and B (ETA and ETB) with a double-antibody sandwich protocol. Antibodies against both toxins were purified by affinity chromatography from sheep antisera raised against purified ETA and ETB. These affinity-purified antibodies were free of detectable amounts of antibodies to other staphylococcal antigens and neutralized the actions of ETA and ETB. Alkaline phosphatase was conjugated to these antibodies. The enzyme-linked immunosorbent assay, which could detect at least 3 ng of ETA and ETB per ml, was used to quantitate the toxins in the culture supernatant fluids of staphylococcal strains. Thus, the kinetics of ETA and ETB synthesis and of ETA and ETB release into the supernatant fluids were determined; other determinations included the roles of carbon dioxide concentration, pH, glucose concentration, temperature, and agitation on the production of ETA and ETB.
