Rapid detection and enumeration of pathogenic Vibrio parahaemolyticus in raw vegetables from retail outlets
2011
This study aims to determine the frequency and density of potentially pathogenic Vibrio
parahaemolyticus, defned as those possessing thermostable-direct hemolysin (tdh) and/or tdh-related hemolysin
(trh) genes, in raw salad vegetables at retail level in Selangor, Malaysia. A combination of Most Probable
Number - Polymerase Chain Reaction (MPN-PCR) method was applied to detect the presence of tdh and/or
trh gene-possessing V. parahaemolyticus and to enumerate their density in the samples. A total of 276 samples
of vegetables commonly eaten raw in Malaysia (Cabbage = 30; Carrot = 31; Cucumber = 28; Four winged
bean = 26; Indian pennywort = 17; Japanese parsley = 21; Lettuce = 16; Long bean = 32; Sweet potato = 29;
Tomato = 38; Wild cosmos = 8) were analyzed. The samples were purchased from two supermarkets (A and
B) and two wet markets (C and D). With the MPN-PCR technique, about 12.0% of the samples were positive
for the presence of V. parahaemolyticus tdh-positive, with maximum densities of up to 39 MPN/g. The total
frequency of V. parahaemolyticus trh-positive in the samples was 10.1%, with maximum concentration 15
MPN/g. V. parahaemolyticus tdh-positive was most prevalent in samples from Wet Market C (20.78%) and
also in vegetable type Oenanthe stolonifera (Japanese parsley) with 19.0%, while V. parahaemolyticus trh-
positive was predominant in samples from Wet Market D (16.7%) and was most frequent in both Oenanthe
stolonifera (Japanese parsley) and Cucumis sativus (Cucumber) with 14.3% prevalence for each type. The
results highlighted the fact that raw vegetables could be contaminated with virulent V. parahaemolyticus and
could act as a transmission route, thus poses risk to consumers from the consumption of raw vegetables. To
the author’s knowledge, this is the frst assessment of V. parahaemolyticus carrying tdh and trh genes in raw
vegetables from retail outlets in Malaysia.
Keywords:
- Correction
- Source
- Cite
- Save
- Machine Reading By IdeaReader
29
References
9
Citations
NaN
KQI