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The fermentation process is the main formation source of biogenic amines in cheese. The other conditions, like enzymatic reaction, starter culture, temperature, period of maturation, milk treatment, the amount of proteolysis, oxygen, water activity, humidity and pH, can change the rate of the formation of biogenic amines. Tyramine has been defined as quality index for dairy products like cheese. In this work, we have successfully employed the advanced hollow‐fibre electromembrane extraction/dispersive microextraction followed by gas chromatography–mass spectrometry as a rapid and sensitive technique for the determination of biogenic amines including putrescine, tyramine, histamine and cadaverine in Lighvan cheese samples.

Background Community-acquired urinary tract infection (CA-UTI) could be caused by endogenous or exogenous routes. To show this relationship, we investigated molecular fingerprints and genotypes of paired Enterococcus faecalis isolated from the urine of symptomatic patients and their fecal samples. Results Out of the studied patients, 63 pairs of E. faecalis isolates were obtained simultaneously from their urine and feces samples. All the strains were sensitive to vancomycin, linezolid, nitrofurantoin, and daptomycin (MIC value: ≤ 4 µg/ml), while resistance to tetracycline (urine: 88.9%; stool: 76.2%) and minocycline (urine: 87.3%, stool: 71.4%) was detected in most of them. The most common detected virulence genes were included efbA, ace, and gelE. RAPD-PCR and PFGE analyses showed the same patterns of molecular fingerprints between paired of the isolates in 26.9% and 15.8% of the patients, respectively. Conclusions Similarity of E. faecalis strains between the urine and feces samples confirmed the occurrence of endogenous infection via contamination with colonized bacteria in the intestinal tract. Carriage of a complete virulence genotype in the responsible strains was statistically in correlation with endogenous UTI, which shows their possible involvement in pathogenicity of uropathogenic E. faecalis strains.