Indigenous lactic acid bacteria-producing bacteriocins could enhance the microbiological safety of traditional cheeses. This study aimed to detect bacteriocinogenic strains among 35 Lactobacillus plantarum isolated from artisanal, raw sheep-milk cheeses. The isolates were identified by API 50 CHL and speciesspecific PCR. As displayed by agar well-diffusion assay, the cell-free supernatant of L. plantarum LpU4 showed the highest antimicrobial activity against Enterococcus faecalis JH2-2. The activity was not detected after treatment with proteinase K, pepsine and pronase. An active peptide band was shown by tricine-sodium dodecyl sulfate (SDS)-polyacrylamide gel electrophoresis and subsequent bioassay. MALDI-TOF analysis revealed a protein of 4,866.7 Da, having no homology with other known bacteriocins. The novel bacteriocin (named plantaricin LpU4) was heat stable (121°C for 15 min), unaffected by chemicals as Tween 20, SDS, Triton ×100, EDTA, NaCl and exposure to a wide range of pH. The synthetic machinery encoding for the plantaricin was plasmid-located, as deduced by plasmids curing. Activity spectrum included several lactic acid bacteria and Staphylococcus aureus strains having antibiotic resistance phenotype. Plantaricin LpU4 showed a bacteriostatic mode of action and an enhanced activity at acidic pHs. Maximal production (3,200 AU.mL

Raw milk consumption in Italy has increased over the last few years and although raw milk is characterised by cold chain, short shelf-life and the duty of boiling before domestic consumption, it is still considered a hazard. From 2010 to 2013 a monitoring survey of raw milk sold through vending machines was carried out to investigate the occurrence of several foodborne pathogens stipulated in the national legal requirements, i.e. Listeria monocytogenes, Campylobacter spp., Salmonella spp., Escherichia coli O:157 and coagulase-positive Staphylococci. A total of 127 raw milk samples were collected from 19 dairy herds in Tuscany Region, Italy. In addition, the milk samples were tested for the presence and count of Yersinia genus. Results shown that only one sample was positive for non verocytotoxin-producing E. coli O:157, whereas a total of 38 samples (29.9%) were postive for Yersinia genus; of the total 39 isolated bacteria, 23.6% were Y. enterocolitica, 2.4% Y. kristenseni and 4.7% Y. frederiksenii. None isolate was enteropathogenic; serotypes O:5 and O:8 were found in 16.6 and 13.3% of the isolates respectively, whereas none of the serotypes tested was detected in 70% of the isolates. The most probable number method revealed a count value between 0.03 and 24 MPN/mL. Based on these data a general assurance on health safety of raw milk produced and sold in Tuscany could be assessed.

The clinical usefulness of glycated hemoglobin (HbA1C) depends crucially on the accuracy and precision of its assay. When we compared an immunological bench-top analyzer (DCA 2000, Bayer Diagnostici, Milan) to the high-performance liquid chromatography (HPLC) reference method used in a routine hospital laboratory (Diamat and Fast Diamat, Bio-Rad Lab., Milan) by assaying multiple control sera, we found so many sources of systematic analytical errors in the routine use of HPLC as to compromise between-assay precision. DCA 2000 showed intra- and interassay coefficients of variation (CV) of 1.1% and 2.3% with the normal standard serum, 1.0% and 4.2% with the pathological one; Diamat yielded CVs of 1.3% and 7.0%, 1.3% and 5.7%, respectively. Although the measurement of 161 blood samples showed that Diamat usually overestimated HbA1C (paired t-test, P<0.001), a great variability of Diamat performance became evident when the relationship Diamat vs DCA was evaluated day by day over 17 days of observation (analysis of variance, ANOVA, P<0.001). Intra- and interassay CVs of Fast Diamat initially (new instrument still on approval) were 0.6% and 2.5% (normal standard serum), 0.3% and 1.9% (high standard serum), yet after 6 months of routine laboratory use, they became 3.1% and 3.2%, 1% and 12.3%, respectively. Main sources of error were: inaccurate autodilution, unsuitable parameter settings, disregard of the maintenance schedule. We conclude that the tendency to overlook major critical aspects in the routine use of HPLC is detrimental to the quality of HbA1C determination and implies the loss of HbA1C value in clinical practice. Both carefully supervising laboratory quality and checking the likelihood of the analytical result with the clinical setting appear even more important.