Prevalence and quantification ofListeria monocytogenes in chicken offal at the retail level in Malaysia

Abstract

A total of 216 chicken offal samples (chicken liver = 72; chicken heart = 72; chicken gizzard = 72) from wet markets and hypermarkets in Selangor, Malaysia, were examined for the presence and density of Listeria monocytogenes by using a combination of the most probable number and PCR method. The prevalence of L. monocytogenes in 216 chicken offal samples examined was 26.39%, and among the positive samples, the chicken gizzard showed the highest percentage at 33.33% compared with chicken liver (25.00%) and chicken heart (20.83%). The microbial load of L. monocytogenes in chicken offal samples ranged from <3 to 93.0 most probable number per gram. The presence of L. monocytogenes in chicken offal samples may indicate that chicken offal can act as a possible vehicle for the occurrence of foodborne listeriosis. Hence, there is a need to investigate the biosafety level of chicken offal in Malaysia.

Listeriosis in animals, its public health significance (food-borne zoonosis) and advances in diagnosis and control: a comprehensive review

“…Small ruminants, especially sheep, are mostly affected (OIE 2014). L. monocytogenes has been isolated from meat and/or milk of goats, sheep, cattle, pig, chicken, quail, partridge, ostrich and buffaloes Rahimi et al 2012;Derra et al 2013;Hasegawa et al 2013;Kuan et al 2013;Ndahi et al 2014), fish and fishery products (Jayasekaran et al 1996;Karunasagar & Karunasagar 2000;, ice creams, vegetables, other ready-to-eat foods (Lambertz et al 2012;Lambertz et al 2013;Mateus et al 2013;Poulsen & Czuprynski 2013), seafood ) and mushroom production facility (Viswanath et al 2013). In the northern hemispheres, listeriosis has a distinct seasonal occurrence, probably associated with seasonal feeding of silage with the highest prevalence during December through May.…”

Assessment of Listeria monocytogenes in pet food

“…As a result, the combination of these two methods (MPN and PCR) has proved to be simpler, more reliable, and less laborious. In addition, MPN is generally preferred when the level of L. monocytogenes in the sample is expected to be low, i.e., ≤ 10-100 MPN/g [10]. This was further proved by a study conducted by Chen et al [4] as the MPN method was observed to be more precise than direct plating for most of the samples where the levels of L. monocytogenes were low.…”

“…have reported that L. monocytogenes has been isolated from various types of food such as fish, chicken, beef, and poultry [3,10]. When it comes to cat and dog food, there are a very limited data with regard to the contamination of these pet food diets by L. monocytogenes around the world.…”

Development, and complete evaluation, of a novel Most-Probable-Number (MPN) qPCR method for accurate and express quantification of Listeria monocytogenes in foodstuffs

“…This fact represents a main advantage over previously published procedures which take a minimum of 40 h only in the incubation step, [23,44,45] and may take even longer if the confirmation steps are performed by traditional microbiology or conventional PCR [22,[46][47][48]. Additionally, our method demonstrated suitability for application with two different detection chemistries, SYBR Green intercalating dye, which is a more economic approach, and with a hydrolysis probe, which offers additional specificity.…”

“…In these methods, positive tubes are generally confirmed by traditional microbiology, but in recent years the combination with molecular techniques, such as PCR/qPCR, has enhanced the applicability of these protocols. According to previous studies, MPN is especially useful for low-level bacterial contamination (<10-100 MPN/g) [22][23][24].…”