Measure of immunoglobulin G-, M-, and A-specific titers against Legionella pneumophila and inhibition of titers against nonspecific, gram-negative bacterial antigens in the indirect immunofluorescence test for legionellosis

Abstract

A crude extract of Escherichia coli O13:K92:H4 inhibited 97% of positive indirect immunofluorescence titers against a variety of gram-negative bacterial antigens while lowering L. pneumophila titers in only 6% of sera from patients with suspected legionellosis. Legionella-specific titers were the result of IgG, IgM and IgA singly or in combination.