You are here:
OCCURRENCE OF VIRTUENCE FACTOR ACTIVITY RELATIONSHIP (VFAR) IN ESCHERICHIA COLI ISOLATED FROM MUNICIPAL WASTEWATER
Citation:
Boczek*, L A., B. K. Kinkle, AND E W. Rice*. OCCURRENCE OF VIRTUENCE FACTOR ACTIVITY RELATIONSHIP (VFAR) IN ESCHERICHIA COLI ISOLATED FROM MUNICIPAL WASTEWATER. Presented at American Society for Microbiology, New Orleans, LA, May 23 - 27, 2004.
Impact/Purpose:
To inform the public.
Description:
Escherichia coli O157 H:7 has been linked to waterborne outbreaks in the United States and abroad. Methods employed to detect this pathogen typically are cultural based and take advantage of phenotypic traits that are specific for this serotype. These phenotypic characteristics include slow sorbitol fermentation and negative -glucuronidase activity. The main concern with using these techniques is that other enterohemorrhagic E. coli (EHEC) strains do not produce the same phenotypic characteristics as strain E. coli O157. These other strains also have been implicated in disease. As a result potential strains of pathogenic E. coli may go undetected.
his study incorporated virulence factor activity relationship (VFAR) to detect EHEC organisms in wastewater effluents. A (VFAR) is a research tool that is currently under review as a way to detect such waterborne pathogens. EHEC organisms produce specific virulence factors, including enterohemolysin, intimin alpha and intimin gamma and one or more Shiga-like toxins I and II (SXTI, SXTII). Molecular probing for one or more of these virulence factors could be a powerful tool for examining waterborne EHEC outbreaks.
Seven municipal wastewater treatment plants from across the United States were surveyed. Each sample was screened for organisms producing the virulence factor enterohemolysin. 393 isolates of E. coli produced enterohemolysin. The isolates were serotyped and analyzed for presence of SXT I, SXTII, EAE, and intimin protein A. Serotyping analysis resulted in several serotypes, none of which were E. coli O157 H:7. Two samples were positive for the virulence factor intimin gamma, encoded by the EAE gene. None of the enterohemolysin positive strains were positive for presence of SXT I, SXTII, or intimin alpha. Probing for VFAR in municipal wastewater effluents allowed for the detection of enterohemolysin positive E. coli.