Bacterial contamination of vegetables served in hospitals.

Abstract

OBJECTIVES: To study bacterial contamination of fresh vegetables before cleaning and before serving to patients in 14 hospitals. MATERIAL AND METHOD: Aerobic plate count was performed and emphasized on total viable aerobic bacteria, fecal coliform, fecal Escherichia coli and enteric pathogens in fresh vegetables including romaine lettuce, onion, parsley, celery and tomato before cleaning and before serving. Hospital nutrition officers who were involved in food purchasing and processing were interviewed. RESULTS: One hundred and six of 403 of fresh vegetable samples (26.3%) before cleaning were contaminated with > 10(7) colony forming unit per gram (CFU/gram) of viable aerobic bacteria, 106 of 178 samples (59.6%) contained MPN/fecal coliform >1,100 /gram, 78 samples (43.8%) contained MPN fecal E. coli >10/gram. Enteric bacteria were isolated from 7.2% of the total 304 samples including non typhoid Salmonella (1 sample), Vibrio cholerae non O1/O139 (7 samples) and Aeromonas species (14 samples). Forty of 396 ready to serve vegetable samples (10.1%) contained > 10(7) CFU/gram of viable aerobic bacteria. Seventy five of 183 (40.9%) samples contained >1,100 MPN fecal coliform/gram and 43 (23.5%) contained >10 MPN fecal E. coli/gram. Enteric bacteria were also detected in 7.6% of the samples including V. cholerae non O1/O139 (6 samples) and Aeromonas species (17 samples). There were three different ways in obtaining fresh vegetables to the hospitals: by auction (50%), wholesalers (21.4%) and retailers (14.2%). There were also different standards of transportation, packaging, delivery and food processing, particularly cleaning methods. CONCLUSION: Ready-to-eat fresh vegetables were contaminated in high percentages with microorganisms in the number that exceeded the standard. Better management is required to safeguard patients.