Listeria monocytogenes in raw salad vegetables sold at retail level in Malaysia

Abstract

a b s t r a c tA range of commercially available vegetables (n = 306) that are consumed in the minimally processed state in Malaysia was examined for the presence of Listeria spp. and Listeria monocytogenes to provide information on the occurrence of such organisms in these vegetables. Analysis was carried out using the most probable number-polymerase chain reaction (MPN-PCR) method. It was found that Listeria spp. and L. monocytogenes could be detected in 33.3% and 22.5% of the vegetables respectively. L. monocytogenes was more frequently detected in Vigna unguiculata (Japanese parsley) at 31.3% and Oenanther stolonifera (yardlong bean) at 27.2%.

Microbiological quality and safety of minimally processed vegetables marketed in Campinas, SP – Brazil, as assessed by traditional and alternative methods

“…On the other hand, L. monocytogenes has been barely linked to foodborne disease outbreaks in which vegetables are the foods implicated (Harris et al, 2003), but it has been constantly isolated from vegetables (Cordano & Jacquet, 2009;Little et al, 2007;Oliveira, Ribeiro et al, 2010;Ponniah et al, 2010). Therefore, the evaluation of the presence of these microorganisms in MPV is of great relevance.…”

“…Several studies have reported on the occurrence of foodborne pathogens in vegetables, particularly in MPV, such as Salmonella spp. (Bhagwat, 2004;Bohaychuk et al, 2009;Elviss et al, 2009;Islam et al, 2004;Khoo et al, 2009;Salleh et al, 2003;Sant'Ana, Landgraf, Destro, & Franco, 2011), pathogenic Escherichia coli (Balagué et al, 2006), and Listeria monocytogenes (Aguado, Vitas, & García-Jalón, 2004;Cordano & Jacquet, 2009;Little et al, 2007;Oliveira, Ribeiro, Bergamini, & Martinis, 2010;Ponniah et al, 2010;Vitas & Garcia-Jalon, 2004). Studies have also been focused on the MPV shelf-life and hygiene indicators microorganisms, such as mesophilic and psychrotrophic microorganisms, Pseudomonas spp., coliforms, and E. coli (Abadias, Usall, Anguera, Solsona, & Viñas, 2008;Fröder et al, 2007;Ilic, Odomeru, & LeJeune, 2008;Meldrum et al, 2009).…”

Preshly Eaten Leafy Vegetables: A Source of Food Borne Pathogens?

“…Further, presence of Listeria spp. in vegetables, such as cabbage, lettuce, tomato, watermelon, oranges have been reported in many countries, including Sri Lanka (Gunasena et al 1995;Caggia et al 2009;Ponniah et al 2010). Further, WHO reports that leafy green vegetables are of great concern in terms of microbiological hazards (WHO, 2008).…”

MPN-PCR detection and antimicrobial resistance of Listeria monocytogenes isolated from raw and ready-to-eat foods in Malaysia

“…Although listeriosis infections are rare, the fatality rate is as high as 20%e30% annually (Allerberger, 2003;Yucel et al, 2005). To date, there are no documented listeriosis infection cases in Malaysia (Hassan, Endang, Son, Raha, & Gulam, 2001;Ponniah et al, 2010); however, without safeguards, such infections may occur. Protective measures, such as the development of a surveillance and detection system concerning food safety, are fundamental to ensure that raw and processed foods derived from fish, chicken and meats are safe for human consumption.…”