Bacterial Pathogens in the Food Industry: Antibiotic Resistance and Virulence Factors of Salmonella enterica Strains Isolated from Food Chain Links

Abstract

Salmonella is one of the most important foodborne pathogens. Fifty-three strains of Salmonella deposited in the Culture Collection of Industrial Microorganisms—Microbiological Resources Center (IAFB) were identified using molecular and proteomic analyses. Moreover, the genetic similarity of the tested strains was determined using the PFGE method. Main virulence genes were identified, and phenotypical antibiotic susceptibility profiles and prevalence of resistance genes were analyzed. Subsequently, the occurrence of the main mechanisms of β-lactam resistance was determined. Virulence genes, invA, fimA, and stn were identified in all tested strains. Phenotypic tests, including 28 antibiotics, showed that 50.9% of the strains were MDR. The tet genes associated with tetracyclines resistance were the most frequently identified genes. Concerning the genes associated with ESBL-producing Salmonella, no resistance to the TEM and CTX-M type was identified, and only two strains (KKP 1597 and KKP 1610) showed resistance to SHV. No strains exhibited AmpC-type resistance but for six Salmonella strains, the efflux-related resistance of PSE-1 was presented. The high number of resistant strains in combination with multiple ARGs in Salmonella indicates the possible overuse of antibiotics. Our results showed that it is necessary to monitor antimicrobial resistance profiles in all food chain links constantly and to implement a policy of proper antibiotic stewardship to contain or at least significantly limit the further acquisition of antibiotic resistance among Salmonella strains.

Newly Isolated Virulent Salmophages for Biocontrol of Multidrug-Resistant Salmonella in Ready-to-Eat Plant-Based Food

“…Typhimurium strain KKP 3080. Data on the phenotypic profiles of antibiotic resistance and the presence of antibiotic resistance genes were presented in the previous article [ 14 ]. Salmonella strains were isolated from food products in 2010 and 2019 ( Table 1 ).…”

“…Salmonella enterica subsp. enterica serovar Typhimurium strain KKP 3080 exhibited a resistance profile to eleven antibiotics, belonging to four different classes of antibiotics (penicillins, cephalosporins, fluoroquinolones, and aminoglycosides) [ 14 ]. The second strain, Salmonella enterica subsp.…”

“…The bacterial strains have been isolated and deposited in the Culture Collection of Industrial Microorganisms—Microbiological Resources Center (IAFB). The taxonomic identification of most of the bacteria used was determined during previous studies or in this study, in accordance with the procedure described in our articles [ 14 , 87 ]. Moreover, the Salmonella strains were sent to the National Salmonella Center (Medical University of Gdańsk, Gdansk, Poland) for serotyping.…”

“…The most common sources of collective outbreaks of food poisoning and foodborne infections were contaminated milk and other dairy products, ready meals, eggs and products containing them, pork and poultry meat, seafood, and secondarily contaminated food of plant origin [ 13 ]. Our research on antibiotic resistance profiles of Salmonella isolated from various links of the food chain in Poland showed that 50.9% of the tested strains were MDR [ 14 ].…”

The Resistance and Virulence Characteristics of Salmonella Enteritidis Strain Isolated from Patients with Food Poisoning Based on the Whole-Genome Sequencing and Quantitative Proteomic Analysis

“…Enteritidis) are the most common serotypes causing Salmonella outbreaks. 1 S . Enteritidis has a wide variety of host species and strong pathogenicity, which can be transmitted to humans through undercooked or raw infected foods (especially meat and eggs), causing fever, abdominal pain, diarrhea, as well as urinary tract infections, arthritis, meningitis, and even death.…”