Bacterial load comparison of marine fish collected and commercially obtained for human consumption in western region of Yucatan Peninsula, Mexico

Document Type : Primary Research paper



This study determined the presence of human pathogenic bacteria in fish muscle, recollected at moment of their capture and during their process for sale in marketing sites. The samples were recollected in eighth touristic and fishing zones of Mexican Caribbean. Samples were inoculated by duplicates in agar plates of specific environment of: S-S, EMB and TCBS and were incubated at 36ºC during 24 hrs.. Strains were identified according to Merck (1994) criteria and finally, in order to confirm the identification with the commercial kit API-20E. Species of different bacterial families were identified, such as: Enterobacteriaceae; Salmonella hirschfeldii, Salmonella schottmulleri, Salmonella parathipi, Salmonella typhi, Salmonella enteritidis, Proteus miriabilis, Proteus rettgeri, Proteus vulgaris, Citrobacter freundii, Citrobacter amanolaticus and three varieties of Escherichia Coli; Pseudomonadaceae: Pseudomonas fluorescens; Aeromonadaceae: Aeromonas hydrophila and Vibrionaceae: Vibrio fluviales, V. cholerae El Tor and V. parahaemolyticus. The 70.6% of the samples presented a bacterial growth; 46% in recently captured fish, and 54% in market fish. It was demonstrated that fish is already contaminated by pathogenic bacteria in their natural environment and that handling during their commercialization does not significantly increase their bacterial load.