Diversity and Antibiotic Resistance Profiles of Listeria monocytogenes Serogroups in Different Food Products from the Transylvania Region of Central Romania

Abstract

The aim of this study was to assess the presence and antimicrobial susceptibility profile of the molecularly serogrouped Listeria monocytogenes isolates in different animal origin food products, collected from a county situated in the historical region of Transylvania, Central Romania. A total of 7.7% (17/221) of the screened samples were positive for L. monocytogenes , with an isolation frequency of 6.2% (8/130) in the ready-to-eat products (i.e., sausages, ham and smoked specialties), 12.8% (6/47) in raw meat (i.e., minced pork, pork organs and snails), and 6.8% (3/44) in dairy (i.e., assortment of cheeses) samples. 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%), respectively. All isolates were resistant to benzylpenicillin and fusidic acid. Resistance was also detected towards oxacillin (88.2%), fosfomycin (82.4%), clindamycin (76.5%), imipenem (52.9%), ciprofloxacin (41.2%), rifampicin (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 about 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.

Antimicrobial Resistance and Virulence Characterization of Listeria monocytogenes Strains Isolated from Food and Food Processing Environments

“…The published studies have reported the increasing of L. monocytogenes strains’ resistance to the entire range of antibiotics of different classes [ 27 , 32 , 35 , 42 , 43 , 44 , 45 , 46 , 47 , 48 ]. The study analysed resistance to 12 antimicrobial agents, and demonstrated that the analysed L. monocytogenes strains were susceptible to a considerable proportion of the analysed agents except clindamycin, meropenem, penicillin G, and trimethoprim/sulfamethoxazole.…”

Genetic Characterization of Listeria from Food of Non-Animal Origin Products and from Producing and Processing Companies in Bavaria, Germany

“…Genotypic and phenotypic resistances to fluoroquinolones (here, ciprofloxacin and moxifloxacin were tested) were shown ( Table 2 ), and ciprofloxacin resistance was reported in other studies [ 41 , 66 , 69 ]. We detected the norB gene that confers resistance to fluoroquinolones with an antibiotic efflux mechanism [ 33 ].…”

“…In our study, every L. monocytogenes isolate showed phenotypic resistance to benzylpenicillin ( Table 3 ). Tîrziu et al detected L. monocytogenes isolates out of FAO, all of which showed benzylpenicillin resistance [ 66 ]. Furthermore, benzylpenicillin resistance in isolates from RTE vegetables was documented [ 67 ].…”

Impact of High-Pressure Processing (HPP) on Listeria monocytogenes—An Overview of Challenges and Responses

“…L. monocytogenes poses an ongoing threat to the food industry, particularly at facilities producing RTE-type foods [ 11 ]. In recent years, there has been a steady increase in antibiotic resistance among L. monocytogenes strains isolated from food and food production environments (especially for the antibiotics used to treat listeriosis), and it is, therefore, necessary to monitor changes with regard to the antibiotic resistance of L. monocytogene s strains isolated from food and the emergence of multi-resistant strains [ 11 , 44 , 51 , 54 , 55 , 56 , 57 , 58 , 59 , 60 , 61 , 62 ].…”