SalmonellaContamination Associated with Bacterial Soft Rot of Fresh Fruits and Vegetables in the Marketplace

Abstract

Wash water from 66% of 401 samples of fresh fruits and vegetables collected in the marketplace and affected by bacterial soft rot were positive for suspected strains of Salmonella, i.e., black, hydrogen sulfide-positive colonies on Salmonella-Shigella agar incubated for 24 h at 37°C. By comparison, 30% of 402 healthy samples were positive. Incidence of suspected Salmonella in broth enrichment cultures was 59% in 533 soft rotted samples and 33% in 781 healthy samples. Thirty percent of 166 representative strains of suspected Salmonella, selected at random from 20 different commodities, were confirmed to be Salmonella by physiological and serological tests. Adjusting incidence values accordingly, Salmonella contamination was potentially present in at least 18 to 20% of soft rotted samples and in 9 to 10% of healthy samples. Wash water from 120 paired healthy and soft rotted fruits and vegetables contained an average of 1.0 × 105 and 3.7 × 106 CFU/ml, respectively, of suspected Salmonella-a ratio of...