Prevalence, characterization and antimicrobial resistance of Listeria monocytogenes isolated from beef meat in Meknes city, Morocco

Abstract

Introduction Listeria monocytogenes is one of the most pathogenic bacteria related to the consumption of contaminated food. This study aims to determine the prevalence of L. monocytogenes in raw beef meat in Meknes city of Morocco, to evaluate its pathogenicity and resistance to antimicrobials.Methods During four seasons, a total of 140 samples were collected from supermarkets, butcheries and Souk (weekly traditional market). The PCR method was used to examine the presence of specific and virulence genes in the isolated strains, and also to identify their serotypes. The antimicrobial resistance was determined.Results The results show a prevalence of 7.14% which depends on retail sites and also on the season's variation. The majority of the strains were detected in butcheries (6 strains), and supermarkets (4 strains). Moreover, the majority of strains were detected during summer (50%). Concerning virulence genes, the seven researched genes were detected in 100% of isolated strains. The majority of strains were of the (1/2a, 1/2c, 3a and 3c) serogroup (70%), while two of them were of the (1/2b, 3b, 4b and 4d) serogroup (20%). All isolates were resistant to at least one antimicrobial, while three strains were resistant to nine tested antimicrobials. However, they were highly susceptible to amikacin, imipenem, gentamicin, sulfamethoxazole and chloramphenicol.Conclusions According to results, isolated L. monocytogenes from analyzed beef meat shows a high level of pathogenicity and resistance to the most used antimicrobials in listeriosis therapy, which calls for the severe application of quality systems at the slaughterhouses and retail sites level.

Virulence properties of Listeria monocytogenes isolated from meat and meat contact surfaces in a slaughterhouse

“…Studies from other countries include the research by Teixeira et al (2020) who reported the presence of L. monocytogenes in 12% (6/50) of beef samples in Brazil. Boukili et al (2020) detected L. monocytogenes in 7.14% (10/140) of analyzed beef meat samples in Morocco. Zhang et al (2021) determined that L. monocytogenes was present in 29.29% (70/239) of raw, intermediate and end meat products, and in 12.2% (29/239) of meat contact surface samples such as the floor, walls, transport units, pipes, trash can and weighing equipment, as well as the hands, clothes, and shoes of the handlers in Shanghai.…”

Molecular genetic studies of Listeria monocytogenes isolates from different animal species in Ukraine

“…Так, якщо виявляють тільки ген lmo0737, то такий ізолят відносять до серотипу 1/2а або 3a, а наявність тільки гена ORF2819 -до 1/2b, 3b або 7. До серотипів 1/2c або 3c можна віднести лістерії, в яких виявлено гени lmo0737 та lmo1118, а якщо ORF2819 та ORF2110 -до 4b, 4d або 4e [4,7,23].…”