VIBRIO-MIMICUS DIARRHEA FOLLOWING INGESTION OF RAW TURTLE EGGS

Clinical and epidemiological characteristics of diarrhea associated wi th Vibrio mimicus were identified in 33 hospitalized patients referred to the Costa Rican National Diagnostic Laboratory Network between 199 1 and 1994. The relevant symptoms presented by patients included abund ant watery diarrhea, vomiting, and severe dehydration that required in travenous Dhaka solution in 83% of patients but not fever, Seroconvers ion against V. mimicus was demonstrated in four patients, from whom ac ute- and convalescent-phase sera were obtained, Those sera did not sho w cross-reaction when tested against Vibrio cholerae O1 strain VC-12, All the V. mimicus isolates from these cases produced cholera toxin (C T) and were susceptible to commonly used antibiotics, Attempts to isol ate this bacterium from stool samples of 127 healthy persons were not successful. Consumption of raw turtle eggs was recalled by 11 of the 1 9 (58%) individuals interviewed, All but two V. mimicus diarrheal case s were sporadic, These two had a history of a common source of turtle (Lepidochelys olivacea) eggs for consumption, and V. mimicus was isola ted from eggs from the same source (a local market). Among the strains , variations in the antimicrobial susceptibility pattern were observed , None of the strains recovered from market turtle eggs nor the four i solates from river water showed CT production, Further efforts to demo nstrate the presence of CT-producing V. mimicus strains in turtle eggs were made. Successful results were obtained when nest eggs were teste d, In this case, it was possible to isolate CT- and non-CT-producing s trains, even from the same egg. For CT detection we used PCR, enzyme-l inked immunosorbent assay (ELISA), and Y-1 cell assay, obtaining a 100 % correlation between ELISA and PCR results, Primers Col-1 and Col-2, originally described as specific for the V. cholerae O1 ctxA gene, als o amplified a 302-bp segment with an identical restriction map from V. mimicus. These results have important implications for epidemiologica l surveillance in tropical countries where turtle eggs are used for hu man consumption, serving as potential sources of cholera-like diarrhea .