Abstract:
Escherichia coli is the predominant facultative anaerobe of the microbiota in the human
colon. Infections due to pathogenic E. coli may be limited to the mucosal surfaces or can
disseminate throughout the whole body, with symptoms ranging from enteric diarrheal
disease, to urinary tract infections, or sepsis. E. coli carrying virulence genes provides
different pathogenic strategies that confer serious effects on human hosts, namely
different types of diarrhea. Raw meat samples, potential reservoirs of E. coli, were
chosen for sampling to detect and characterize the E. coli types present therein, according
to their respective virulence gene(s). Therefore, 600 raw meat samples were collected
from Beirut Slaughterhouse on weekly basis intervals, over a period spanning from
February till September 2002. The detection of uspA gene was indicative of an E. colicontaining
sample. uspA is a gene used by investigators to differentiate E. coli from other
gram-negative bacteria. Eleven virulence genes were chosen on the basis of different
pathogenic strategies: Shiga toxin genes (VTI, VT2, and VT2e), intimin gene (eaeA),
cytotoxic necrotizing factors genes (CNFI and CNF2), enteroaggregative gene (EAgg),
enteroinvasive gene (EInv), heat-stable and heat-labile genes (STI, ST2, LTI). Multiplex
