Extinction of Vibrio cholerae in acidic substrata: contaminated fish marinated with lime juice (ceviche)

Millions of Vibrio cholerae O1 El Tor were rapidly eliminated when added to commercial ceviche prepared by marination of mahi-mahi fish in lime juice. Likewise, large masses of viable vibrios present in laboratory contaminated fish, were readily eliminated after immersion in lime juice, during the preparation of ceviche. The killing effect was evident within 5 min of exposure of vibrios to lime juice, with reductions of more than 99.9 per cent of the initial bacterial mass. After 2h of marination of fish with lime juice (the minimum recommended), no vibrios were detected in the lowest working dilutions (1:10, 1:100). The Vibrio mass eliminated by lime juice was 2 to 6 logarithms greater than the maximum infectious dose, and 4 to 8 logs greater than the minimum infectious dose to induce cholera El Tor. Also, the killing time was shorter than the elapsing time between preparing and serving food in homes or restaurants. The traditional marination of fish with lime juice or its addition to seafood and meals immediately before consumption, should be protected and promoted to prevent infection with cholera vibrios. In the face of an epidemic of cholera, consumption of ceviche prepared with lime juice would be one of the safest ways to avoid infection with V. cholerae

Extinction of Vibrio cholerae in acidic substrata: contaminated cabbage and lettuce treated with lime juice

Lime juice killed millions of Vibrio cholerae O1, El Tor, Inaba, present on cabbage and lettuce contaminated in the laboratory. The lethal effect was evident within 5 min of exposure to lime juice. No vibrios could be recovered at dilution 1:10 using alkaline peptone water (APW) and thiosulfate-citrate-bile salts-saccharose agar (TCBS). More than 99.9 per cent of the initial inoculum was effectively destroyed. The number of vibrios killed by lime juice was 2 to 6 logarithms greater than the maximum infecting dose, and 4 to 8 logs greater than the minimum infecting dose for cholera El Tor. The time interval needed for killing was smaller than the usual waiting time for serving food in homes and restaurants. The addition of lime juice to non-acidic foods, beverages and water, is strongly recommended to prevent infection with cholera vibrios and other acid-sensitive microorganisms. This measure is particularly important for rural and slum populations in the tropics and subtropics