The aim of this study was to compare the microbiological quality of cooked sausages produced with a traditional salt content (2.1%) and reformulated batches with a salt content reduced to 1.7%. The reformulation was tested on two types of comminuted meat products – Špekáčky sausage with a diameter of up to 46 mm or Bologna-type sausages in diameter of 85 mm (Gothaj sausage) or 75 mm (Junior sausage). The total viable count (TVC) increased only slightly during the four-week storage (4 ± 1 °C) of all batches of Špekáčky sausage. Comparing batches 1.7 and 2.1, there is an evident difference in the number of CFU/g, with samples of Špekáčky 1.7 showing numbers of bacteria higher by approximately 1 logarithmic order throughout practically the entire storage period (P = 0.001). The population of lactic acid bacteria (LAB) remained well beneath a value of 5.0 log CFU/g even at the end of the experiment. For Bologna-type sausages, the TVC was either beneath the limit of detection or at its boundary in all samples. LAB were not detected during storage of Bologna-type sausages. The results confirmed that the proportion of salt in cooked sausages can be reduced to 1.7% without negatively affecting the shelf life or safety of the final products.
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- MeSH
- kontrola potravin MeSH
- lidé MeSH
- potravní doplňky MeSH
- probiotika * MeSH
- Check Tag
- lidé MeSH
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 aadE 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.
- MeSH
- antibiotická rezistence * genetika MeSH
- Lactobacillus * klasifikace metabolismus účinky léků MeSH
- mikrobiální testy citlivosti metody MeSH
- potravinářská mikrobiologie metody MeSH
- probiotika klasifikace MeSH
- zajištění potravin metody MeSH
- Publikační typ
- klinická studie MeSH
- práce podpořená grantem MeSH
Lactobacilli are bacteria with important implications in food and feed fermentation. Detailed knowledge of the lactobacilli composition is of high relevance to food and health control, various industrial or biotechnological applications, etc., but accurate identification of the Lactobacillus species is not an easy task. In this study, three methods, i.e. polymerase chain reaction (PCR), amplified 16S rDNA restriction analysis with restrictase MseI (16S-ARDRA), and the matrix-assisted laser desorption/ionization time-of-flight mass spectrometry (MALDI-TOF MS) were evaluated for their capabilities to identify Lactobacillus species. After comparison of the three methods on a set of 19 type/reference Lactobacillus strains, 148 strains isolated from dairy and meat products were characterized by PCR and MALDI-TOF MS. The strains were differentiated into nine and ten lactobacilli species by PCR and MALDI-TOF MS, respectively, with nine of these species being congruent. The success rates of species level assignment were 77% for PCR and 93% for MALDI-TOF MS that proved superior in the species identification. However, to differentiate between closely related Lactobacillus species, MALDI-TOF MS needs to be used in combination with genotypic techniques to achieve a more reliable identification.
- MeSH
- Bacteria chemie klasifikace izolace a purifikace MeSH
- fermentace MeSH
- genotyp MeSH
- Lactobacillus genetika izolace a purifikace MeSH
- maso mikrobiologie MeSH
- mléčné výrobky mikrobiologie MeSH
- polymerázová řetězová reakce metody MeSH
- potravinářská mikrobiologie MeSH
- ribozomální DNA MeSH
- RNA ribozomální 16S MeSH
- spektrometrie hmotnostní - ionizace laserem za účasti matrice metody MeSH
- Publikační typ
- časopisecké články MeSH
- práce podpořená grantem MeSH
- srovnávací studie MeSH
- MeSH
- dítě v ústavní péči MeSH
- dítě MeSH
- komunikace MeSH
- lidé MeSH
- psychosociální deprivace MeSH
- psychoterapie metody MeSH
- Check Tag
- dítě MeSH
- lidé MeSH
