Calidad microbiológica y análisis de patógenos (Shigella y Salmonella) en lechuga

the microbiological quality of 37 lettuce samples of the creole variety (lactuca sativa var. capitata l.) obtained from different intermediaries at the provinces of san josé and cartago, in costa rica was analyzed. the samples were collected through a non-probabilistic sampling with intentional selection. escherichia coli (nmp/g) was quantified as indicator of fecal contamination and the presence of specific pathogens (shigella and salmonella) was determined by culture and multiplex-pcr. in 65% of the samples analyzed we detected e. coli, even though we did not find shigella or salmonella by multiplex-pcr or culture. a possible explanation is that the shigella or salmonella contamination levels may have been under the detection limits for both methods (less than 104 cfu/g for shigella, and less than 102 cfu/g for salmonella). these results establish an important basis for continuing with this research subject and analyzing other sources of transmission of shigella and salmonella contamination, since both pathogens are frequent in the region.