title: Development of a rapid agglutination latex test for diagnosis of enteropathogenic and enterohemorrhagic Escherichia coli infection in developing world: defining the biomarker, antibody and method.
abstract: BACKGROUND
  Enteropathogenic and enterohemorrhagic Escherichia coli (EPEC/EHEC) are human intestinal pathogens responsible for diarrhea in both developing and industrialized countries. In research laboratories, EPEC and EHEC are defined on the basis of their pathogenic features; nevertheless, their identification in routine laboratories is expensive and laborious. Therefore, the aim of the present work was to develop a rapid and simple assay for EPEC/EHEC detection. Accordingly, the EPEC/EHEC-secreted proteins EspA and EspB were chosen as target antigens.
  
  
  METHODS
  First, we investigated the ideal conditions for EspA/EspB production/secretion by ELISA in a collection of EPEC/EHEC strains after cultivating bacterial isolates in Dulbecco's modified Eagle's medium (DMEM) or DMEM containing 1% tryptone or HEp-2 cells-preconditioned DMEM, employing either anti-EspA/anti-EspB polyclonal or monoclonal antibodies developed and characterized herein. Subsequently, a rapid agglutination latex test (RALT) was developed and tested with the same collection of bacterial isolates.
  
  
  RESULTS
  EspB was defined as a biomarker and its corresponding monoclonal antibody as the tool for EPEC/EHEC diagnosis; the production of EspB was better in DMEM medium. RALT assay has the sensitivity and specificity required for high-impact diagnosis of neglected diseases in the developing world.
  
  
  CONCLUSIONS
  RALT assay described herein can be considered an alternative assay for diarrhea diagnosis in low-income countries since it achieved 97% sensitivity, 98% specificity and 97% efficiency.
authors.affiliation: Laboratório de Bacteriologia, Instituto Butantan, São Paulo, São Paulo, Brazil.
authors.forename: Letícia B
authors.initials: LB
authors.lastname: Rocha
authors.affiliation: Laboratório de Bacteriologia, Instituto Butantan, São Paulo, São Paulo, Brazil.
authors.forename: Anna R R
authors.initials: AR
authors.lastname: Santos
authors.affiliation: Laboratório de Bacteriologia, Instituto Butantan, São Paulo, São Paulo, Brazil.
authors.forename: Danielle D
authors.initials: DD
authors.lastname: Munhoz
authors.affiliation: Laboratório de Bacteriologia, Instituto Butantan, São Paulo, São Paulo, Brazil.
authors.forename: Lucas T A
authors.initials: LT
authors.lastname: Cardoso
authors.affiliation: Laboratório de Bacteriologia, Instituto Butantan, São Paulo, São Paulo, Brazil.
authors.forename: Daniela E
authors.initials: DE
authors.lastname: Luz
authors.affiliation: Laboratório de Bacteriologia, Instituto Butantan, São Paulo, São Paulo, Brazil.
authors.forename: Fernanda B
authors.initials: FB
authors.lastname: Andrade
authors.affiliation: Laboratório de Bacteriologia, Instituto Butantan, São Paulo, São Paulo, Brazil.
authors.forename: Denise S P Q
authors.initials: DS
authors.lastname: Horton
authors.affiliation: Laboratório de Bacteriologia, Instituto Butantan, São Paulo, São Paulo, Brazil.
authors.forename: Waldir P
authors.initials: WP
authors.lastname: Elias
authors.affiliation: Laboratório de Bacteriologia, Instituto Butantan, São Paulo, São Paulo, Brazil.
authors.forename: Roxane M F
authors.initials: RM
authors.lastname: Piazza
mesh_terms: D000907:Antibodies, Bacterial / Q000032:analysis; D015373:Bacterial Typing Techniques / Q000379:methods*; D015415:Biomarkers / Q000032:analysis; D003906:Developing Countries; D004926:Escherichia coli / Q000302:isolation & purification*; D004927:Escherichia coli Infections / Q000175:diagnosis* / Q000382:microbiology; D029968:Escherichia coli Proteins / Q000032:analysis*; D006801:Humans; D007841:Latex Fixation Tests / Q000379:methods*
chemical_list: D000907:Antibodies, Bacterial; D015415:Biomarkers; D029968:Escherichia coli Proteins