Abstract: This study used molecular serogrouping to assess the presence and antimicrobial susceptibility profile of Listeria monocytogenes isolates from food products of different animal origin, collected from a county situated in the historical region of Transylvania in central Romania. Seventeen (7.7%) of 221 screened samples were positive for L. monocytogenes; these included 8 (6.2%) of 130 ready-to-eat products (i.e., sausages, ham, and smoked specialties), 6 (12.8%) of 47 raw meat samples (i.e., minced pork, pork organs, and snails), and 3 (6.8%) of 44 dairy samples (i.e., assortment of cheeses). The identified L. monocytogenes serogroups were 1/2a-3a (47.1%), 4b-4d-4e (29.4%), 1/2c-3c (11.8%), and 4a-4c (11.8%). All isolates were resistant to benzylpenicillin and fusidic acid. Resistance was also detected toward oxacillin (88.2%), fosfomycin (82.4%), clindamycin (76.5%), imipenem (52.9%), ciprofloxacin (41.2%), rifampin (41.2%), trimethoprim-sulfamethoxazole (29.4%), and tetracycline (29.4%). On the other hand, all isolates proved susceptible to gentamicin, moxifloxacin, teicoplanin, vancomycin, tigecycline, erythromycin, and linezolid. All tested strains exhibited multidrug resistance, resulting in the expression of a total of 12 resistance profiles. These findings extend the understanding of the spread of an important pathogen in Romanian food products, highlighting a substantial public health issue and medical concern, especially for consumers with a compromised health status.
Keywords: Listeria monocytogenes; Antimicrobial resistance; Detection; Food; Serogrouping.
Published 2022 by the International Association for Food Protection.