title: Different assay conditions for detecting the production and release of heat-labile and heat-stable toxins in enterotoxigenic Escherichia coli isolates.
abstract: Enterotoxigenic Escherichia coli (ETEC) produce heat-labile (LT) and/or heat-stable enterotoxins (ST). Despite that, the mechanism of action of both toxins are well known, there is great controversy in the literature concerning the in vitro production and release of LT and, for ST, no major concerns have been discussed. Furthermore, the majority of published papers describe the use of only one or a few ETEC isolates to define the production and release of these toxins, which hinders the detection of ETEC by phenotypic approaches. Thus, the present study was undertaken to obtain a better understanding of ST and LT toxin production and release under laboratory conditions. Accordingly, a collection of 90 LT-, ST-, and ST/LT-producing ETEC isolates was used to determine a protocol for toxin production and release aimed at ETEC detection. For this, we used previously raised anti-LT antibodies and the anti-ST monoclonal and polyclonal antibodies described herein. The presence of bile salts and the use of certain antibiotics improved ETEC toxin production/release. Triton X-100, as chemical treatment, proved to be an alternative method for toxin release. Consequently, a common protocol that can increase the production and release of LT and ST toxins could facilitate and enhance the sensitivity of diagnostic tests for ETEC using the raised and described antibodies in the present work.
authors: Bacteriology Laboratory, Butantan Institute, São Paulo, SP 05503-900, Brazil. denise.horton@butantan.gov.br.
authors: Letícia B
authors: LB
authors: Rocha
authors: Christiane Y
authors: CY
authors: Ozaki
authors: Denise S P Q
authors: DS
authors: Horton
authors: Caroline A
authors: CA
authors: Menezes
authors: Anderson
authors: A
authors: Silva
authors: Irene
authors: I
authors: Fernandes
authors: Fabio C
authors: FC
authors: Magnoli
authors: Tania M I
authors: TM
authors: Vaz
authors: Beatriz E C
authors: BE
authors: Guth
authors: Roxane M F
authors: RM
authors: Piazza
mesh_terms: D000818:Animals; D000900:Anti-Bacterial Agents / Q000494:pharmacology; D001427:Bacterial Toxins / Q000276:immunology / Q000378:metabolism*; D001647:Bile Acids and Salts / Q000494:pharmacology; D001681:Biological Assay / Q000379:methods*; D002939:Ciprofloxacin / Q000494:pharmacology; D054307:Enterotoxigenic Escherichia coli / Q000187:drug effects / Q000302:isolation & purification / Q000378:metabolism*; D004768:Enterotoxins / Q000276:immunology / Q000378:metabolism*; D004797:Enzyme-Linked Immunosorbent Assay; D029968:Escherichia coli Proteins / Q000276:immunology / Q000378:metabolism*; D005260:Female; D007074:Immunoglobulin G / Q000276:immunology; D008034:Lincomycin / Q000494:pharmacology; D008297:Male; D008807:Mice, Inbred BALB C; D011817:Rabbits
chemical_list: D000900:Anti-Bacterial Agents; D001427:Bacterial Toxins; D001647:Bile Acids and Salts; D004768:Enterotoxins; D029968:Escherichia coli Proteins; D007074:Immunoglobulin G; C034151:heat stable toxin (E coli); D002939:Ciprofloxacin; D008034:Lincomycin; C027538:heat-labile enterotoxin, E coli