Food Sci. Technol, Campinas, Ahead of Print, 2020 1/7 1 Food Science and Technology DOI D httpsI//doi.org/10.1590/fst.11520 OSSN 0101-2061 (Print) OSSN 1678-457X (Dnline) 1 Introduction Meat is considered as an outstanding source of high-quality protein, fat, carbohydrates, vitamins and minerals and is delicious, palatable or easy to digest (Sharma & Bist, 2011). Raw meat eaten by more than 80% of the population is one of the main sources of foodborne diseases (Hassan Ali et al., 2010), meat is also considered to be an ideal medium for bacterial growth due to available favorable environmental factors (pH, temperature, minerals and other growth factors) (Russell, 2001). Enterobacteriaceae group are ofen of global concern and is very difcult due to its close association with both raw and processed meat contamination. E. coli, Proteus Salmonella and Klebsiella sp. has always been chief species in all food poisoning circumstances linked to some meat products (Food and Agriculture Drganization, 2000). L. monocytogenes is responsible for several listeriosis outbreaks related to meat product consumption. Onitially, L monocytogenes are present in small quantities in foodstufs, and can multiply at varying rates during chilled storage depending on the type of food product, both under aerobic and anaerobic conditions, adapt to disinfectants and adhere to diferent surfaces (Meloni, 2015). Fraudulent or accidental mislabeling of food products is still widespread worldwide, which could not be identifed using traditional techniques Adulteration may also include the use of low-priced meat like chicken meat as a high-priced meat like beef meat. Terefore, these consumer groups need methods of detecting meat species (dog, cat, pork, etc.) in the food (Haunshi et al., 2009). Developments in molecular biology have facilitated high precision identifcation of plant, bacteria, and animal species (Sasazaki et al., 2004). Polymerase chain reaction (PCR), restriction fragment length polymorphism (RFLP), and random amplifed polymorphic DNA (RAPD) techniques were widely used to classify meat species (Arslan et al., 2005). Accordingly, the present study examined raw meat samples from various animal species randomly collected from street vendors and famous Giza Governorate retail markets. Samples were examined microbiologically and species-specifc multiplex PCR methods were created for the detection and identifcation of pork, cat, dog, chicken and rat or mouse tissues. 2 Materials and methods 2.1 Meat samples Raw meat samples from 11 diferent animal species were collected randomly from Giza Governorate’s butcher shops, common retail markets, veterinary faculties, Zoo and hospitals. Bacteriological assessment and multiplex-PCR test for the detection of meat adulteration of diferent animal species Azza Sayed Mohamed ABUELNAGA 1 , Khaled Abd El-Hamid ABD EL-RAZOK 2 * , Nagwa Sayed ATA 1 , Riham Hasaan HEDOA 1 , Elgabry Abd-Elalim ELGABRY 1 , Mona Mohamed Hassan SDLOMAN 1 , Hanan Shawky Abdel Wahab MAROE 1 a Received 12 Mar., 2020 Accepted 20 Apr., 2020 1 Department of Microbiology and Immunology, National Research Center, Giza, Egypt 2 Department of Animal Reproduction, National Research Center, Giza, Egypt *Corresponding authorI khaled707@hotmail.com, khaledemara707@yahoo.com Abstract Meat samples of various animal species have been obtained from Giza Governorate’s butcher shops, common retail markets, veterinary faculties, Zoo and hospitals. Physical, bacteriological, and molecular analysis was carried out on the meat samples. Physical examination showed that typical and untypical meat difered. Bacteriological examination showed the highest TCC was found in horse meat while the least was in goat meat. Te total count of S. aureus was the highest in donkey and dog whilst the least in pork meat. As for E.coli, donkey meat was the highest while bufalo and mutton meat were the lowest. Te highest total Listeria monocytogenes and Salmonella Species count were in horse, donkey, rat and dog meat but zero in the other species examined. Multiplex-PCR targeting partial-length of cytochrome b (cyt b) gene of mitochondrial DNA (mtDNA) was used for the discovery of adulteration of beef meat with chicken, pork, dog, cat and rat tissue. Ot showed high specifcity in diferentiating the six animal species meat. Te study points out the importance of taking serious steps to control species meat adulteration that may lead to transmission of severe foodborne diseases and more studies need to be implemented to apply new and easy meat adulteration detection protocols. Keywords: multiplex PCR; meat adulteration; bacteriological; Egypt. Practical Application: Species-specifc PCR for distinguishing fve diferent animal species in raw beef meat to prevent meat adulteration and to show the severity of meat adulteration in food-borne pathogens transmission in Egypt.