Preliminary data on the microbial profile of dry and wet aged bovine meat obtained from different breeds in Sardinia

This study aimed to evaluate the influence of dry and wet aging on microbial profile and physicochemical characteristics of bovine loins obtained from four animals of two different breeds, namely two Friesian cull cows and two Sardo-Bruna bovines. During dry and wet aging aerobic colony count, Enterobacteriaceae, mesophilic lactic acid bacteria, Pseudomonas, molds and yeasts, Salmonella enterica, Listeria monocytogenes and Yersinia enterocolitica, pH and water activity (aw) were determined in meat samples collected from the internal part of the loins. Moreover, the microbial profile was determined with sponge samples taken from the surface of the meat cuts. Samples obtained from Friesian cows were analyzed starting from the first day of the aging period and after 7, 14, and 21 days. Samples obtained from the Sardo Bruna bovines were also analyzed after 28 and 35 days. Wet aging allowed better control of Pseudomonas spp. during storage that showed statistically lower levels (P>0.05) in wet-aged meats with respect to dry-aged meats during aging and particularly at the end of the period (P>0.01) in both cattle breeds. At the end of the experiment (21 days), aerobic colony count and Pseudomonas in Fresian cows’ dry-aged meats showed mean levels >8 log, while lactic acid bacteria mean counts >7 log were detected in wet-aged meats of both cattle breeds. In meats submitted to dry aging, pH was significantly higher (P<0.01) with respect to wet-aged meats at all analysis times and in both cattle breeds. Aw showed a stable trend during both dry and wet aging without significant differences. These preliminary results highlight the critical importance of the strict application of good hygiene practices during all stages of production of these particular cuts of meat intended for aging

Boosting, Probing and Switching-Off Visible Light-Induced Photocurrents in Eumelanin-Porous Silicon Hybrids

A relatively intense photocurrent density up to 3.8 mA/cm2 was induced by visible light in n+-doped porous silicon (n-PSi) coated with a eumelanin thin film produced by ammonia-induced solid state polymerization (AISSP) of 5,6-dihydroxyindole (DHI). The photocurrent was not affected by acetic acid vapors but was irreversibly abated by gaseous ammonia. No detectable photocurrent was observed using p+-PSi as the inorganic substrate. These results point to eumelanin as a powerful enhancer of PSi photoresponse to visible light via hole-type electrical conduction

Differential induction of dyskinesia and neuroinflammation by pulsatile versus continuous L-DOPA delivery in the 6-OHDA model of Parkinson's disease

Neuroinflammation is associated with L-DOPA treatment in Parkinson's disease (PD), suggesting a role in L-DOPA-induced dyskinesia (LID), however it is unclear whether increased inflammation is specifically related to the dyskinetic outcome of L-DOPA treatment. Diversely from oral L-DOPA, continuous intrajejunal L-DOPA infusion is associated with very low dyskinetic outcome in PD patients. We reproduced these regimens of administration in 6-OHDA-lesioned hemiparkinsonian rats, where dyskinetic responses and striatal neuroinflammation induced by chronic pulsatile (DOPAp) or continuous (DOPAc) L-DOPA were compared. Moreover, we investigated the contribution of a peripheral inflammatory challenge with lipopolysaccharide (LPS), to DOPAp-induced dyskinetic and neuroinflammatory responses. Rats 6-OHDA-infused in the medial forebrain bundle received two weeks treatment with DOPAp, DOPAc via subcutaneous osmotic minipumps, or DOPAp followed by DOPAc. L-DOPA plasma levels were measured in all experimental groups. An independent group of rats received one peripheral dose of LPS 24 h before DOPAp treatment. Abnormal involuntary movements (AIMs) were evaluated as a rat model of LID. Immunoreactivity (IR) for OX-42, microglial and neuronal TNF-α, iNOS and GFAP was quantified in denervated and contralateral striatum. In addition, serum TNF-α was measured. The 6-OHDA denervation induced a mild microgliosis in the striatum two weeks after neurotoxin infusion, and increased TNF-α IR in microglia. Rats receiving the DOPAp treatment developed AIMs and displayed increased striatal OX-42, microglial TNF-α, iNOS and GFAP. Moreover, TNF-α IR was also increased in a subpopulation of striatal neurons. Conversely, DOPAc did not induce AIMs or inflammatory responses in either drug-naïve animals or rats that were previously dyskinetic when exposed to DOPAp. Serum TNF-α was not altered by any L-DOPA treatment. LPS pre-treatment increased the degree of DOPAp-induced AIMs and striatal IR for OX-42, TNF-α, iNOS and GFAP. Altogether the present findings indicate that in the 6-OHDA model, chronic L-DOPA induces striatal inflammatory responses, which however depend upon the administration regimen and the dyskinetic outcome of drug treatment. The potentiation of dyskinetic responses by LPS suggests a reciprocal causal link between neuroinflammation and LID

<i>Salmonella</i> and <i>Yersinia enterocolitica</i> through the pig meat chain in Sardinia: occurrence, antimicrobial resistance and genetic insight

The study aimed to characterize Salmonella and Yersinia enterocolitica detected in fattening pigs in Sardinia, examining genetic similarity and antimicrobial resistance of isolates from farms and slaughterhouses and evaluating carcass hygiene. Environmental samples were collected from six pig farms, and the same pigs were also sampled at the slaughterhouses. Palatine tonsils, mesenteric lymph nodes, colon content, and carcass surface samples were collected and tested for Salmonella and Y. enterocolitica. Antimicrobial resistance testing and whole genome sequencing were performed on all isolates. Carcass surface samples were tested for total aerobic colony count (ACC) and Enterobacteriaceae count (EBC). Y. enterocolitica was found in two farms (33%), while Salmonella was absent in environmental farm samples. At slaughterhouses, 13.1% of pigs were found positive for Salmonella (lymph nodes, colon content, and palatine tonsils samples), but Y. enterocolitica was not detected. Salmonella isolates were typed as monophasic S. Typhimurium ST34 and S. Goldcoast ST358, with few allelic differences among isolates of the same ST. Salmonella ST34 showed resistance towards ampicillin, streptomycin, sulfonamide, and tetracycline (blaTEM-1B, aph(3´´)-Ib, sul2 and tetB genes, R-type ASSuT). Y. enterocolitica isolates (biotype 2, ST853, and ST859) showed resistance to ampicillin and amoxicillin-clavulanic acid (blaA gene). Process hygiene criteria were generally met, with mean (log10 CFU/cm2 ± standard deviation) values for ACC and EBC being 2.23±0.74 and 0.75±0.81. Pigs of Sardinia are confirmed carriers of Salmonella and Y. enterocolitica, but overall hygienic status in farms and slaughterhouses in Sardinia is acceptable. Monophasic S. Typhimurium and Y. enterocolitica isolates showed typical resistance patterns. Monophasic S. Typhimurium ST34 isolates with R-type ASSuT are confirmed as epidemic clones