Impact of ozone and UV irradiation sanitation treatments on the survival of Salmonella and the physical–chemical characteristics of hen eggs

Summary: Salmonella is the second main cause of foodborne illness in poultry production. It is one of the most problematic zoonoses in terms of public health worldwide because of the difficulty in controlling it and its significant morbidity and mortality rates. Recent surveys have shown that small flocks of laying hens have the same or higher prevalence of salmonellosis than larger flocks, mainly due to a lack of control actions, that is, the control of mice and wild animals, employees, and poor management practices. In this regard, different physical and chemical procedures have proven efficacious for reducing external and/or internal Salmonella contamination. This research evaluated the effect of ozone and UV-C rays on Salmonella growth and hen egg quality. Microbiological evaluation was performed on 120 eggs: negative control (C−), eggs not contaminated with Salmonella; positive control (C+), eggs contaminated; contaminated ozonate-treated (O, 600 mg/h for 2 h); and contaminated UV-C–irradiated (ʎ, 254 nm for 15 s) eggs. Moreover, 30 eggs were used (10/group) for the quality assessments of the C, O, and UV-C groups. A 2 log10 CFU/g reduction in Salmonella on contaminated eggs was found in the UV-C group compared with the C+ and O groups. Compared with UV-C treatment, ozonization reduced the amount of yolk tocols and carotenoids (by 2 times). The lipid oxidative status decreased (−1.5 times), similar to the cholesterol level (−28.5%), whereas the amount of cholesterol and its oxidized products increased (+82.1%) in the O group compared with the C group. UV-C irradiation is an effective strategy to reduce Salmonella contamination in eggs without negatively affecting the quality. Therefore, UV treatments remain among the more promising procedures

Detection of Testudinid alphaherpesvirus, Chlamydia spp., Mycoplasma spp., and Salmonella spp. in free‑ranging and rescued Italian Testudo hermanni hermanni.

Testudo hermanni is included as near‑threatened in the Red List of the International Union for Conservation of Nature, while T. hermanni hermanni is considered endangered in the Italian Red List. Appropriate management of smuggled or seized wild individuals is recommended before their reintroduction into the wild. Accordingly, a health monitoring study was carried out. During 2014‑2016, 133 oral swabs and 121 cloacal swabs were collected from a total of approximately 180 free‑ranging and rescued T. hermanni hermanni from eight different Italian regions to investigate the presence of DNA of Testudinid alphaherpesvirus (TeAHV), Chlamydia spp. and Mycoplasma spp. in the oral cavity, and Salmonella spp. isolates in the cloaca. Mycoplasma spp. was detected in 52 out of 87 (59.77%) of rescued and in 1 out of 46 free‑ranging (2.17%) individuals; 33 out of 53 (62.26%) Mycoplasma spp. positive samples were typed as M. agassizii by PCR. Salmonella spp. was isolated from 45 out of 121 (37.19%) cloacal swabs, typed into 14 serovars, and characterized for complete antimicrobial susceptibility. A significantly different distribution of Salmonella spp. isolates was found in 2016 in comparison with 2014 and 2015, without any difference between free‑ranging and rescued tortoises. All the tested tortoises were negative for TeAHV and Chlamydia spp. These results are considered a baseline information critical to monitor the dynamics of these microorganisms in free‑ranging and rescued populations of T. h. hermanni, and to correctly approach the management of rescued animals and possible relocation programs

Discovering microbiota and volatile compounds of surströmming, the traditional Swedish sour herring

none13noIn this study, the microbiota of ready-to-eat surströmming from three Swedish producers were studied using a combined approach. The pH values of the samples ranged between 6.67±0.01 and 6.98±0.01, whereas their aw values were between 0.911±0.001 and 0.940±0.001. The acetic acid concentration was between 0.289±0.009 g/100 g and 0.556±0.036 g/100 g. Very low concentrations of lactic acid were measured. Viable counting revealed the presence of mesophilic aerobes, mesophilic lactobacilli and lactococci as well as halophilic lactobacilli and lactococci, coagulase-negative staphylococci, halophilic aerobes and anaerobes. Negligible counts for Enterobacteriaceae, Pseudomonadaceae and total eumycetes were observed, whereas no sulfite-reducing anaerobes were detected. Listeria monocytogenes and Salmonella spp. were absent in all samples. Multiplex real-time PCR revealed the absence of the bont/A, bont/B, bont/E, bont/F, and 4gyrB (CP) genes, which encode botulinic toxins, in all the samples analyzed. Metagenomic sequencing revealed the presence of a core microbiota dominated by Halanaerobium praevalens, Alkalibacterium gilvum, Carnobacterium, Tetragenococcus halophilus, Clostridiisalibacter, and Porphyromonadaceae. Psychrobacter celer, Ruminococcaceae, Marinilactibacillus psychrotolerans, Streptococcus infantis and Salinivibrio costicola were detected as minority OTUs. GC-MS analysis of volatile components revealed the massive presence of trimethylamine and sulfur compounds. Moreover, 1,2,4-trithiolane, phenols, ketones, aldehydes, alcohols, esters and long chain aliphatic hydrocarbons were also detected. The data obtained allowed pro-technological bacteria, which are well-adapted to saline environments, to be discovered for the first time. Further analyses are needed to better clarify the extent of the contribution of either the microbiota or autolytic enzymes of the fish flesh in the aroma definition.restrictedLuca Belleggia, Lucia Aquilanti, Ilario Ferrocino, Vesna Milanović, Cristiana Garofalo, Francesca Clementi, Luca Cocolin, Massimo Mozzon, Roberta Foligni, M. Naceur Haouet, Stefania Scuota, Marisa Framboas, Andrea OsimaniBelleggia, Luca; Aquilanti, Lucia; Ferrocino, Ilario; Milanovic, Vesna; Garofalo, Cristiana; Clementi, Francesca; Cocolin, Luca; Mozzon, Massimo; Foligni, Roberta; Naceur Haouet, M.; Scuota, Stefania; Framboas, Marisa; Osimani, Andre

The Enter-Vet Italian surveillance network: data on samples of pig origin from 2002 to 2005

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Role of verocytotoxigenic Escherichia coli in the swine production chain

Shiga toxin-producing Escherichia coli (STEC) can cause severe clinical diseases in humans, such as haemorrhagic colitis (HC) and haemolytic-uremic syndrome (HUS). Although ruminants, primarily cattle, have been suggested as typical reservoirs of STEC, many food products of other origins, including pork products, have been confirmed as vehicles for STEC transmission. Only in rare cases, pork consumption is associated with severe clinical symptoms caused by high pathogenic STEC strains. However, in these outbreaks, it is unknown whether the contamination of food products occurs during swine processing or via cross-contamination from foodstuffs of different sources. In swine, STEC plays an important role in the pathogenesis of oedema disease. In particular a Shiga toxin subtype, named stx2e, it is considered as a key factor involved in the damage of swine endothelial cells. On the contrary, stx2e-producing Escherichia coli has rarely been isolated in humans, and usually only from asymptomatic carriers or from patients with mild symptoms, such as uncomplicated diarrhoea. In fact, the presence of gene stx2e, encoding for stx2e, has rarely been reported in STEC strains that cause HUS. Moreover, stx2e-producing STEC isolated from humans and pigs were found to differ in serogroup, their virulence profile and interaction with intestinal epithelial cells. Because of the limited epidemiologic data of STEC in swine and the increasing role of non-O157 STEC in human illnesses, the relationship between swine STEC and human disease needs to be further investigated

Prevalence and characteristics of verotoxigenic Escherichia coli strains isolated from pigs and pork products in Umbria and Marche regions of Italy

AbstractIn total 1095 samples from 675 pork products, 210 swine colon contents, and 210 swine carcass sponge swabs were collected in Umbria and Marche regions of Italy and examined for the presence of Shiga toxin-producing Escherichia coli (STEC), also known as Verotoxin-producing E. coli (VTEC). After an enrichment step, each sample was analysed by real-time PCR to detect the stx1, stx2, and eae genes. stx-Positive samples were further tested for the “top five” serogroup markers (O157, O26, O103, O111, O145) and cultured onto selective media. The isolates were assigned to stx subtypes and tested for the presence of aaiC and aggR genes. Out of 420 swine samples, 38.6% faecal samples and 13.8% carcass sponge swabs were stx-positive. In total, 33 E. coli STEC isolates were obtained from 30 samples (4 carcasses and 26 colon contents) indicating a culture-positive rate of 7.1%. A higher culture-positive rate was observed in faecal samples (12.4%) than in carcass sponge swabs (1.9%). Out of 675 pork samples, 19 (2.8%) were stx-positive. No STEC strains were isolated from stx-positive pork products. We concluded that STEC isolation from foodstuffs remains difficult, despite the application of ISO/TS 13136:2012. Furthermore, in accordance with the results of studies conducted in other countries, we observed that most of swine STEC strains carried stx2e gene and lacked of virulence genes, such as eae, aaiC and aggR, indicative of potential pathogenic characteristics for humans. Although the majority of STEC isolates did not express virulence factors correlating with severe human diseases, the association between swine STEC strains and human illness requires further investigations

Detection and Virulence Characterization of Listeria monocytogenes Strains in Ready-to-Eat Products

The public health risk posed by Listeria monocytogenes in ready-to-eat (RTE) foods depends on the effectiveness of its control at every stage of the production process and the strain involved. Analytical methods currently in use are limited to the identification/quantification of L. monocytogenes at the species level, without distinguishing virulent from hypovirulent strains. In these products, according to EU Regulation 2073/2005, L. monocytogenes is a mandatory criterion irrespective of strain virulence level. Indeed, this species encompasses a diversity of strains with various pathogenic potential, reflecting genetic heterogeneity of the species itself. Thus, the detection of specific L. monocytogenes virulence genes can be considered an important target in laboratory food analysis to assign different risk levels to foods contaminated by strains carrying different genes. In 2015–2016, a severe invasive listeriosis outbreak occurred in central Italy, leading to the intensification of routine surveillance and strain characterization for virulence genetic markers. A new multiplex real-time polymerase chain reaction targeting main virulence genes has been developed and validated against the enzyme-linked fluorescent assay (ELFA) culture-based method. Results of the improved surveillance program are now reported in this study

Development and Characterization of Xanthan Gum and Alginate Based Bioadhesive Film for Pycnogenol Topical Use in Wound Treatment

Pycnogenol (PYC) is a concentrate of phenolic compounds derived from French maritime pine; its biological activity as antioxidant, anti-inflammatory and antibacterial suggests its use in the treatment of open wounds. A bioadhesive film, loaded with PYC, was prepared by casting, starting with a combination of two biopolymer acqueous solutions: xanthan gum (1% wt/wt) and sodium alginate (1.5% wt/wt), in a 2.5/7.5 (wt/wt) ratio. In both solutions, glycerol (10% wt/wt) was added as plasticizing agent. The film resulted in an adhesive capable to absorb a simulated wound fluid (~ 65% wt/wt within 1 h), therefore suitable for exuding wounds. The mechanical characterization showed that the film is deformable (elastic modulus E = 3.070 ± 0.044 MPa), suggesting adaptability to any type of surface and resistance to mechanical solicitations. PYC is released within 24 h by a sustained mechanism, achieving a maximum concentration of ~ 0.2 mg/mL, that is safe for keratinocytes, as shown by cytotoxicity studies. A concentration of 0.015 mg/mL is reached in the first 5 min after application, at which point PYC stimulates keratinocyte growth. These preliminary results suggest the use of PYC in formulations designed for topical use

Bioadhesive Polymeric Films Based on Red Onion Skins Extract for Wound Treatment: An Innovative and Eco-Friendly Formulation

The onion non-edible outside layers represent a widely available waste material deriving from its processing and consumption. As onion is a vegetable showing many beneficial properties for human health, a study aiming to evaluate the use of extract deriving from the non-edible outside layers was planned. An eco-friendly extraction method was optimized using a hydroalcoholic solution as solvent. The obtained extract was deeply characterized by in vitro methods and then formulated in autoadhesive, biocompatible and pain-free hydrogel polymeric films. The extract, very soluble in water, showed antioxidant, radical scavenging, antibacterial and anti-inflammatory activities, suggesting a potential dermal application for wounds treatment. In vitro studies showed a sustained release of the extract from the hydrogel polymeric film suitable to reach concentrations necessary for both antibacterial and anti-inflammatory activities. Test performed on human keratinocytes showed that the formulation is safe suggesting that the projected formulation could be a valuable tool for wound treatment