The absence of acquired resistance to antimicrobials has become an important criterion in evaluation of the biosafety of lactobacilli used as industrial starter or probiotic cultures. The aim of this study was to assess antibiotic resistance in starter and non-starter lactobacilli of food origin. Minimal inhibitory concentrations of ampicillin, chloramphenicol, clindamycin, erythromycin, gentamicin, kanamycin, streptomycin, tetracycline and vancomycin were established in 81 strains of lactobacilli ( L. acidophilus , L. animalis , L. brevis , L. curvatus , L. delbrueckii , L. fermentum , L. helveticus , L. paracasei , L. plantarum , L. rhamnosus and L. sakei ) by the microdilution method. The strains were classified as susceptible or resistant to antimicrobials based on the cut-off values according to the EFSA guideline. Sixty-two strains (77% food isolates, 76% starter or adjunct cultures) were resistant to at least one antimicrobial agent (the most frequently to aminoglycosides). Adjunct cultures showed a higher antibiotic resistance (80%) than starters (60%). Four multiresistant strains (3 food isolates, 1 adjunct culture) were analyzed by whole genome sequencing. One potentially transferable aad E gene (responsible for streptomycin resistance) was detected only in one multi-drug resistant strain of L. animalis originating from an adjunct culture. Thus, there is a risk of horizontal transmission of this gene. It is necessary to eliminate such strains from use in the food industry. This study provides relevant data concerning the use of lactobacilli in safe food production. To ensure food safety, detailed characterization of resistance to antimicrobials is necessary not only in starter strains but also in non-starter lactic acid bacteria isolated from food products.

The aim of this study was to analyse the influence of the contamination level of fresh meat on the bacterial population in raw material before cooking and on the microbiota of cooked hams following heat treatment. The effect of incubation temperatures of 6.5 and 15 °C on the results obtained was also evaluated during the bacteriological investigation. The total viable count (TVC), the number of Enterobacteriaceae and lactic acid bacteria (LAB) were determined in the samples. LAB were isolated from 13 samples out of the 50 fresh meat samples. The species most frequently detected included Latilactobacillus sakei, Leuconostoc carnosum, Enterococcus gilvus, Latilactobacillus curvatus, and Leuconostoc gelidum. The meat sampled after the brine injection and tumbler massaging showed higher bacterial counts compared to fresh meat samples (p < 0.001). The heat treatment destroyed the majority of the bacteria, as the bacterial counts were beneath the limit of detection with a few exceptions. Although the primary cultivation of samples of cooked hams did not reveal the presence of LAB, their presence was confirmed in 11 out of 12 samples by a stability test. Bacteria of the genus Leuconostoc were the most numerous.

The aim of this study was to assess the germination and growth of two strains of Bacillus cereus following the artificial inoculation of six selected hot dishes with spores which were then stored at temperatures of 40, 50, and 60 °C for 0.5, 1.0, 2.0, 2.5, 3.0, and 4.0 h. The water activity of the prepared meals varied between 0.967 and 0.973 and the salt content between 0.74 and 1.40%. The pH value of four dishes exceeded 6.0, but for two (tomato sauce and ratatouille) it was 4.6. The tested strain DSM 4312 showed good growth abilities and attained a population exceeding 6.0 log CFU/g within 4 h at 40 °C in foods with pH values > 6.0. The study demonstrated that a drop in food temperatures to 40 °C is risky, while no growth of B. cereus was detected within 4 h at 50 and 60 °C. The growth rate of B. cereus is conditioned not merely by environmental conditions (temperature, pH values, food composition), but also by the bacterial strain.

With increasing popularity of food delivery services, the microbial safety of transported meals should be ensured. An effect of the type of a meal (cooked rice; mashed potatoes; mushroom sauce), inner primary packaging (sugarcane bagasse [SB] tray; polypropylene [PP] tray), secondary container (polyester/polyethylene foam/aluminum foil [PPA] bag; PP box) on the time interval of the internal hot ready-to-eat (RTE) meal temperature decrease to the value critical for Bacillus cereus growth (40 °C) was tested during a simulated delivery; in aliquot samples of the same meals, B. cereus growth was quantified presuming a natural contamination of the meals. Type of a meal had no effect on the tested time interval (p > 0.05). Packaging a meal in the PP tray as compared to the SB tray and inserting primary trays into the PP box instead of PPA bag delayed (p < 0.05) the internal meal temperature decrease by 50 and 15 min, respectively. Average B. cereus counts in the naturally contaminated meals after the four-hour culturing at 40 °C was 2.99 log CFU·g⁻¹. It was concluded that a hot RTE meal delivered up to four hours under the tested conditions is not likely to facilitate B. cereus growth above unacceptable levels.

Protective cultures are an increasingly industrially relevant biopreservation tool for meat and meat products, responding to simultaneous demands for microbiological safety, extended shelf life, and reduced reliance on synthetic preservatives within clean-label frameworks. This review summarizes current advances in protective cultures applied to meat systems, with emphasis on technological functions, efficacy boundaries, and safety-related due diligence. We discuss the dominant inhibitory mechanisms of lactic acid bacteria and related protective taxa—acidification, competitive exclusion, and antimicrobial metabolites (including bacteriocins)—and highlight why performance is strongly strain- and matrix-dependent under realistic storage conditions. Practical applications are reviewed across raw meats (spoilage delay under refrigeration and vacuum/MAP) and processed or ready-to-eat products, where post-processing surface application emerges as a critical control point for limiting Listeria monocytogenes outgrowth during chilled storage. Key implementation constraints include technological compatibility and sensory neutrality, which are influenced by product buffering capacity, salt content, available fermentable substrates, packaging atmosphere, and temperature. From a safety perspective, we synthesize evidence on antimicrobial resistance in food-associated cultures and outline contemporary qualification strategies combining phenotypic susceptibility testing with genome-based screening to exclude acquired and potentially transferable resistance determinants. Overall, protective cultures should be viewed as a targeted hurdle integrated into holistic preservation systems rather than a standalone substitute for hygiene and process control.