Listeria monocytogenes Biofilms in the wonderland of food industry

The foodborne pathogen Listeria monocytogenes is a concern in food safety because of its ability to form biofilm and to persist in food industry. In this mini-review, the issue represented by this pathogen and some of the latest efforts performed in order to investigate the composition of biofilms formed by L. monocytogenes are summarized

Shiga toxin-producing Escherichia coli O157, O26 and O111 in cattle faeces and hides in Italy

Introduction: Ruminants are regarded as the natural reservoir for Shiga toxin-producing Escherichia coli (STEC), especially of serogroup O157. Materials and methods: During 2011 and 2012, 320 samples (160 faecal samples from the rectum and 160 hide samples from the brisket area) were collected from 160 cattle at slaughter in Northern Italy during warm months (May to October). Cattle were reared in different farms and their age at slaughter ranged between nine months and 15 years, most of them being culled cattle (median age: six years; average age: 4.6 years). Samples were tested by immunomagneticseparation technique for E coli O157 and O26 and by a screening PCR for stx genes followed by cultural detection of STEC. The virulence genes stx1, stx2, eae, and e-hlyA were detected and among stx2-positive isolates the presence of the stx2a and stx2c variants was investigated. Results: Twenty-one of 160 cattle (13.1 per cent; 95 per cent CI 8.3 to 19.4 per cent) were found to be faecal carriers of STEC. STEC O157 was found in 10 (6.3 per cent) samples, STEC O26 in six (3.8 per cent) and STEC O111 in one (0.6 per cent). Four isolates (2.5 per cent) were O not determined (OND). Six out of 160 (3.8 per cent; 95 per cent CI 1.4 to 8.0 per cent) hide samples were positive for STEC; four hides (2.5 per cent) were contaminated by STEC O157 and two (1.3 per cent) by STEC O26. In three cattle (1.9 per cent) STEC from both faeces and hides were detected. Among STEC O157, 87.5 per cent of them carried the stx2c gene and 12.5 per cent carried both stx1 and stx2c genes. No O157 isolate harboured stx2a variant. STEC O26 and O111 carried the stx1 gene only. One OND strain carried both the stx2a and stx2c genes. Conclusions: This study shows that STEC O157 from cattle can harbour the stx2c variant, which is associated with haemolytic uraemic syndrome in humans, and that cattle hides may be a source of human pathogenic STEC O157 and O26 in the slaughterhouse environment

Prevalence of Salmonella enterica in Italian salami and evaluation of isolates survival in a human macrophage-like (U937) cell line.

Salmonella is the second pathogen reported in the European Union (EU) as causative agents of human foodborne diseases (EFSA and ECDC, 2015). In 2014, S. Enteritidis and S. Typhimurium were the two more frequently isolated serovariants in confirmed human cases. The main source of contamination is food of animal origin, especially pig meat, which is largerly consumed in EU (Devine, 2003); in Italy, in particular, the consumption of a wide range of salami produced with pork is very common. Pigs are important reservoir of infection for humans as they are asymptomatic carriers of broad host-range serovars of Salmonella (Fedorka-Cray et al., 2000). From April to December 2015, 155 ground pork and fat mixture samples (corresponding to 155 different batches) used for salami production were tested for Salmonella.All samples were provided by four production plants located in Emilia-Romagna region, northern Italy. Salami batches were tested only in case their ground raw mixture was positive for Salmonella. The detection of Salmonella was performed using a molecular method based on the Real-Time polymerase chain reaction (PCR) and positive samples were confirmed by the ISO 6579:2002 bacteriological standard method . The enumeration of Salmonella in the Real-Time PCR positive samples was performed following the miniaturized Most Probable Number (MPN) technique according to ISO 6579-2:2012. Since the ability of Salmonella to cause systemic disease has been assessed in mice according to their survival and growth in murine cell lines, , we evaluated the capacity of some Salmonella isolatesto survive and replicate within a human macrophages-like cell line (U937). This study was performed to investigate the potential invasiveness for humans of Salmonella strains found in ready-to-eat pork products. Salmonella was isolated from 24/46 (52.2%) of raw mixture samples and from 16/59 (27.1%) of cured salami; eight Salmonella serovars were identified, with S. Derby (12/24; 50.0%) as the most common. The MPN enumeration of Salmonella in raw mixture ranged from 160 MPN/g to < 1.3 MPN/g, while in cured salami it ranged from 8.7 MPN/g to 1.3 MPN/g in seven samples (43.7%), and was < 1.3 MPN/g in the remaining nine (56.3%). Three of the four tested strains of S. Typhimurium 4,[5],12:i:- were able to survive and growth in the human macrophage-like (U937) cell line. On the contrary, one isolate of S. Typhimurium 4,[5],12:i:- and one strain of S. Infantis were not able to to survive

Programa Educação Compromisso de São Paulo: lógica empresarial na rede pública paulista

O Programa Educação Compromisso de São Paulo (PECSP) foi estabelecido com base numa parceria público-privada entre a Secretaria da Educação do Estado de São Paulo e organizações da sociedade civil. A intervenção do setor privado na formulação das políticas educacionais centra-se na adoção da lógica gerencial-empresarial na rede pública paulista. Considerando as relações entre processos de democratização e Educação e tendo como objeto de estudo o PECSP, o objetivo deste trabalho foi analisar em que medida o modelo gerencial do programa se contrapõe ao princípio constitucional da gestão democrática da escola. O recorte temporal da pesquisa abrange o período de 2011 a 2018. A ênfase recai sobre as políticas com maior incidência do modelo gerencial: o Programa Ensino Integral e a Gestão em Foco. Foi conduzida pesquisa documental de abordagem qualitativa, explorando fontes primárias e secundárias. A técnica adotada foi a análise de conteúdo. O referencial teórico-metodológico que sustenta este estudo se inspira nas teorias marxistas para a compreensão da democracia e da Educação no contexto neoliberal e no materialismo histórico-dialético. Esta pesquisa mostrou: a) a presença do setor privado na rede paulista, favorecendo a conformação da escola à lógica gerencial-empresarial, como meio de garantir resultados obtidos em avaliações externas; b) o estabelecimento de objetivos e padrões de desempenho como forma de controle da escola, tornando professores e estudantes responsáveis pelo alcance de resultados; c) a modificação da estrutura educacional como um todo, alterando a finalidade da Educação pública; d) a inexistência de uma efetiva participação da comunidade escolar nos processos decisórios relativos ao PECSP. A relevância desta pesquisa é a compreensão de que o modelo gerencial-empresarial presente na rede paulista não comporta o princípio constitucional da gestão democrática da escola.Não recebi financiament

Low prevalence of Salmonella enterica in cull dairy cattle at slaughter in Northern Italy

In order to evaluate Salmonella carrier status of cull dairy cattle at slaughter, 125 animals were randomly selected during the period February-May 2016. Dairy cows were reared in 89 farms located in two regions of Northern Italy (Lombardy and Emilia-Romagna regions), where bovine milk is primarily used for Parmigiano- Reggiano cheese and Grana Padano cheese production. Samples were collected by swabbing a 400-cm2 area of the brisket hide and by rectoanal mucosal swabs. They were tested following the reference ISO 6579 method and the isolates were serotyped following the Kauffmann-White-Le Minor scheme and genotyped by XbaI PFGE. Salmonella was detected in 1.6% of the brisket hide samples (2/125) (95% CI: 0.4-5.6) and never found in faecal samples (95% CI: 0-3%). The positive cattle were reared in two farms located only in Emilia- Romagna region. The isolates were typed as S. Derby and S. Seftenberg. The comparison of the pulsed-field gel electrophoresis (PFGE) patterns of the bovine strains with all the PFGE patterns of the same serotypes responsible for human salmonellosis cases notified in Emilia-Romagna region in the years 2013-2015 did not find any correspondence. Therefore, the role of cull dairy cattle in transmitting Salmonella to humans seems to be less important than those of pigs and poultry in EU, but more data are needed for completing attribution source studies

Nematodes colonization of pyrite cinders in a phytoremediation study

A phytoremediation programme was applied to a chemical factory site affected by pyrite cinders dumps at Torviscosa (North-Italy). Cinders of pyrite were the residues from production of sulphuric acid and they are extremely contaminated by heavy metals and arsenic. The project focused on the effects of soil amendments and different plant species on phytoremediation efficiency to restore soil health. In this paper we report results about changes in nematodes communities observed in manure treated plots. The experimental trial was prepared as follows: the top cinders layer (20-40 cm) was mixed with the covering soil (0-20 cm) forming a \u201cmixture\u201d that was treated with chemical fertilizers or well-rotted cow manure and then sown with three different metals-accumulating plants: giant reed (Arundo donax L.), sunflower (Helianthus annuus L.) and sorghum (Sorghum bicolor L.). Samples were taken: a) at the initial time on the pyrite cinders and covering soil, separately; b) on the mixture before the application of manure; c) on the mixture cultivated with three species, two months after sowing. Comparison was done on general composition, trophic structure and biodiversity of the nematofauna collected in all the plots. In pyrite cinders nematodes were not detected, probably because of physical properties (heavy silty texture) and high concentration of metals. Highest abundance of nematodes was recorded in sunflower (88 ind/100 g of soil) and lowest abundance was in the mixture before fertilization and sowing (23 ind/100 g of soil). Across all the plots, bacterial feeders were the dominant trophic group ranging between 95.6% in the mixture and 63.7% in sorghum. In these early stages of succession plant feeders were not detected and omnivores were recorded in a low percentage, except for sorghum. In soil covering and in the mixture Cephalobidae was dominant. In the cultivated plots, Rhabditidae was the most abundant family, mainly due to the application of manure. Moreover, in sorghum Diplogasteridae (in particular Butlerius) was 25% of the total community, whereas in sunflower and giant reed did not reach 5% and in the samples collected before the treatments it was not detected. The communities in sorghum seemed to be rather structured, being omnivore-predators quite abundant. The communities in the other cultivated plots were dominated by one family and were not well structured, as demonstrated by Maturity Index and the other calculated Indices. Our results showed that phytoremediation provided to a repopulation of an area extremely compromised. Moreover, analysis of nematofauna could be a useful tool in assessing the degree of soil disturbance and to study the step of the remediation process

Low prevalence of Salmonella enterica in cull dairy cattle at slaughter in Northern Italy

In order to evaluate Salmonella carrier status of cull dairy cattle at slaughter, 125 animals were randomly selected during the period February-May 2016. Dairy cows were reared in 89 farms located in two regions of Northern Italy (Lombardy and Emilia-Romagna regions), where bovine milk is primarily used for Parmigiano-Reggiano cheese and Grana Padano cheese production. Samples were collected by swabbing a 400-cm2 area of the brisket hide and by rectoanal mucosal swabs. They were tested following the reference ISO 6579 method and the isolates were serotyped following the Kauffmann-White-Le Minor scheme and genotyped by XbaI PFGE. Salmonella was detected in 1.6% of the brisket hide samples (2/125) (95% CI: 0.4-5.6) and never found in faecal samples (95% CI: 0-3%). The positive cattle were reared in two farms located only in Emilia-Romagna region. The isolates were typed as S. Derby and S. Seftenberg. The comparison of the pulsed-field gel electrophoresis (PFGE) patterns of the bovine strains with all the PFGE patterns of the same serotypes responsible for human salmonellosis cases notified in Emilia-Romagna region in the years 2013-2015 did not find any correspondence. Therefore, the role of cull dairy cattle in transmitting Salmonella to humans seems to be less important than those of pigs and poultry in EU, but more data are needed for completing attribution source studies

Low prevalence of Salmonella enterica in cull dairy cattle at slaughter in Northern Italy

In order to evaluate Salmonella carrier status of cull dairy cattle at slaughter, 125 animals were randomly selected during the period February-May 2016. Dairy cows were reared in 89 farms located in two regions of Northern Italy (Lombardy and Emilia-Romagna regions), where bovine milk is primarily used for Parmigiano- Reggiano cheese and Grana Padano cheese production. Samples were collected by swabbing a 400-cm2 area of the brisket hide and by rectoanal mucosal swabs. They were tested following the reference ISO 6579 method and the isolates were serotyped following the Kauffmann-White-Le Minor scheme and genotyped by XbaI PFGE. Salmonella was detected in 1.6% of the brisket hide samples (2/125) (95% CI: 0.4-5.6) and never found in faecal samples (95% CI: 0-3%). The positive cattle were reared in two farms located only in Emilia- Romagna region. The isolates were typed as S. Derby and S. Seftenberg. The comparison of the pulsed-field gel electrophoresis (PFGE) patterns of the bovine strains with all the PFGE patterns of the same serotypes responsible for human salmonellosis cases notified in Emilia-Romagna region in the years 2013-2015 did not find any correspondence. Therefore, the role of cull dairy cattle in transmitting Salmonella to humans seems to be less important than those of pigs and poultry in EU, but more data are needed for completing attribution source studies

A learning model for the allocation of training hours in a multistage setting

In line with the continuous improvement theory, the learning phenomenon is often incorporated into models for predicting the evolution of the unitary quality costs. In this paper, the quality metric predicted is the rate of supplied non-conforming units through a learning process with autonomous and induced sources of experience. The former is simply learning by doing, i.e. supplying, whilst the latter is driven by the allocation of training hours to suppliers. A revised learning model with time-varying learning rates is proposed for embracing both these effects into a multistage assembly/production setting. A single-period prevention\u2013appraisal\u2013failure cost function is achieved, and the sample inspection rates adopted among suppliers are also considered in order to evaluate their effect. If these sample rates are given, the goal of allocating the training hours among suppliers is pursued by means of integer linear programming. Otherwise, a mixed-integer quadratic problem arises for the concurrent allocation of training hours and inspection sample rates among suppliers. A case study is finally carried out for demonstrating the applicability of the model, as well as for providing managerial insights