Effects and safety of selected antagonistic bacteria against Escherichia coli in leafy green vegetables

We live in a busy world, where the demand of ready-to-eat (RTE) salad products has increased rapidly in a relatively short time. Despite of being an easy and fast way to add more vegetables to the daily diet, RTE salads have a serious underlying risk and the amount of vegetable-derived foodborne disease outbreaks has been increasing. The aim of the present study is to protect plants against contamination with human pathogens by inoculating spinach (Spinacia oleracea) seeds with antagonists, inherent on leafy green vegetables. Experiments were carried on to observe the effects of selected antagonistic bacteria against non-pathogenic Escherichia coli CCUG29300T contamination on live spinach sprouts, and to test the safety by studying the immune response in mice. In addition, bacterial isolates from RTE rocket salad (Eruca sativa) were identified by 16S rRNA gene sequencing. The putative results show that bagged rocket salad contains bacteria from several different families and genera, the most abundant being Pseudomonas, commonly found from leafy green vegetables and Aeromonas that are omnipresent in soil, water and vegetation. Surprising findings were Rheinheimera, Chryseobacterium, and Shewanella that are more commonly associated with a marine environment. Unfortunately, the antagonistic effect of selected bacteria could not be seen in this study, as no statistically significant differences between treated samples and negative control were found (p>0.05). The seed pellet may work as a physical barrier hindering the inoculation, or has antimicrobial effects that increases the death rate of two antagonists. FACS analysis of Peyer’s patches and mesenteric lymph nodes of mice indicate that the tested antagonists may be able to suppress non-pathogenic E. coli induced inflammation in mice. In Peyer’s patches, the percentage of gated CCR9+CD8+CD69+ cells was significantly lower in the groups A (15.9 (6.2–23.2), p=0.037) and E (17.1 (7.7–25.3), p=0.029) compared with the control group K (30.3 (20.8–72.1)). These percentages were on the similar level with the untreated group N (13.7 (10.3–17.6)). The percentage of TLR2+TLR4+ activated macrophages in the antagonist groups varied between E 22.7 (21.7–35.7) and B 28.9 (18.6–39.1). All results were significantly lower compared with the group K 62.7 (57.2 – 67.9). There were no significant differences in water or feed intakes between groups, which indicates that antagonist treatment do not make mice feel sick. This study supports the current knowledge of leafy green vegetables harbouring a very diverse microflora with genera with potential human pathogens. Despite of poor results in antagonistic effect experiment, preliminary results indicate that selected antagonists do not trigger a negative immune response in miceAs we all may know, fruits and vegetables have numerous health-promoting effects as in minerals, vitamins, and fibre. Living in the busy world make us seeking products that do not require too much preparation and that’s why ready-to-eat (RTE) products are getting popular every day. However, RTE salads and salad mixes may have a microscopic surprise that makes our stomachs to feel uneasy or in the worst case, have more severe consequences. This surprise can be Norovirus, enterohemorrhagic Escherichia coli, or Salmonella. These microbes can be found from water or several other foods, but there are no eliminative steps in salad that remove these harmful visitors. For the consumer who wants to eat RTE salads, the best advice is to check that everything looks fresh. Brown or squished salad leaves may seem harmless, but the salad juice is a very powerful nutrient for bacteria and just simply removing the damaged leaves does not change the situation that the bacteria have had a long time to grow inside the bag. But what can science do? Competition is all around us, also in our salad. The main reason for foodborne illnesses is, that the harmful bacteria have found their way to the salad and been successful in the growth competition. It has been found out that several bacteria, commonly present in the leafy green vegetables can reduce the growth of Escherichia coli, because they are natural part of the microflora of leafy green vegetables. These bacteria can be called antagonists - organisms that are able to interfere the normal growth of harmful bacteria. In this study we added these antagonists to spinach sprouts through the leaves and the seeds, hoping to see the promising antagonistic effect as reduced E. coli concentration. Unfortunately, working with living organisms is not always easy. Even though the antagonist effects have been present in previous experiments, they could not be seen this time as the introduction of the antagonists into the plants did not go as planned. Our bodies undergo constant competition as well. Sometimes we get sick as the first defence line fails to eliminate the intruder or it takes too long. Luckily we have also the adaptive immune system, which contains several specialized cells and is ready to activate whenever needed. As we are using the antagonistic bacteria to suppress E. coli, it is important to make sure that these antagonists are not found as harmful intruders by the immune system. Since it is not possible to test these things straight on humans, an animal study was carried out. The mice were pre-treated with antibiotics and harmless E.coli to have equal bacterial composition in their guts. The antagonists were given to the mice in drinking water, and their well-being was monitored daily. In the end, the immune response of mice was studied by observing the levels of activated defensive cells in their organs. The preliminary results indicate that the antagonists do not change the consumption behaviour of mice, or trigger a negative immune response. Several defensive cell levels were lower in the mice who got the antagonists, compared with those who got only E. coli. This may indicate that the antagonist are able to suppress the immune response caused by E. coli. More work is needed to find an optimal way to introduce the antagonist to the plants, and to study the immune response on deeper levels. However, the results of this study indicate that we may have to be able to fight against harmful visitors of our foods by partnering with the antagonist bacteria, and thereby offer everyday consumers safer ready-to-eat salads to enjoy

Tampereen yliopistollisen sairaalan sarkoomatyöryhmän vuosina 2015−2017 käsittelemät potilastapaukset

Mesenkymaalista alkuperää oleva tukikudos käsittää luun, ruston, sidekudoksen, rasvakudoksen, veren ja lihakset. Tukikudoksen kasvaimet jaetaan luukudoksen sekä pehmytkudoksen kasvaimiin, joista pahanlaatuisia kasvaimia kutsutaan sarkoomiksi. Sarkoomat ovat harvinaisia, iän mukana yleistyviä, ja niitä todetaan Suomessa keskimäärin 250 vuodessa. Tampereen yliopistollisessa sairaalassa toimii moniammatillinen sarkoomatyöryhmä, joka kokoontuu viikoittain keskustelemaan tukikudoksen kasvaimiin liittyvistä lähetteistä sekä todettujen muutosten hoidosta. Diagnosointi pohjautuu kuvantamistutkimuksiin sekä biopsiaan, ja näiden pohjalta potilaan hoito suunnitellaan. Sarkooman parantava hoito on leikkaus, mutta myös sädehoitoa ja kemoterapiaa käytetään joko leikkauksen lisäksi tai tilanteessa, jossa tautia ei enää voida parantaa. Tässä opinnäytetyössä käsiteltiin vuosien 2015–2017 Tampereen yliopistollisen sairaalan sarkoomatyöryhmän pöytäkirjat sekä viikkotapaamisissa käsiteltyjen sarkoomapotilaiden sairauskertomustekstit. Tiedoista verrattiin tukikudoskasvainten ilmaantuvuutta, sukupuolijakaumaa, tyyppijakaumaa aiheesta aiemmin tehtyjen syventävien opintojen tuloksiin. Lisäksi tutkittiin sarkooman hoitopolun sujuvuutta ajallisesti eri hoidon vaiheissa. Tuloksissa nähtiin, että potilasmäärä on kasvanut vuosista 2009–2010 alle 400 potilaasta noin 600 potilaaseen vuodessa, pahanlaatuisten tapausten määrän pysyessä suhteellisesti samalla tasolla. Luukudoksen muutosten ja pehmytkudoksen muutosten määrä hyvän- tai pahanlaatuisuus ja sukupuolijakauma ovat pysyneet myös samoina. Sen sijaan keski-ikä on kaikissa kategorioissa hienoisessa nousussa. Lisäksi nähtiin, että miehillä viive oireiden alusta diagnoosiin oli huomattavasti pidempi naisiin verrattuna, joskin hoitojen aloitus oli miehillä naisia aikaisemmin

Tasapainotettu palkitseminen

Siirretty Doriast

Työurien pituuden kehitys 2000-luvulla

Raportissa esitellään työuran pituuden mittaamista eri menetelmin ja aineistoilla. Erilaiset mittaustavat antavat toisistaan poikkeavia tuloksia työurien keskimääräisestä pituudesta. Tasoeroista riippumatta eri tavoilla saadaan sama päätulos työurien pidentymisestä 2000-luvulla. Kirjan painos on loppu

Bridge under troubled water : turbulence and niche partitioning in fish foraging

Peer reviewe

Exocrine pancreas function decreases during the progression of the beta-cell damaging process in young prediabetic children

Objective: The function of the exocrine pancreas is decreased in patients with type 1 diabetes but it is not known when this defect develops. The current study set out to determine whether the reduced exocrine function becomes manifest after the initiation of islet autoimmunity. Methods: The study was nested in the prospective Type 1 Diabetes Prediction and Prevention study where children with human leukocyte antigen (HLA)-conferred susceptibility are observed from birth. Elastase-1 levels were analyzed from stool samples collected at the time of seroconversion to islet autoantibody positivity and at diagnosis of type 1 diabetes, as well as from samples taken from matched control children of similar age. Results: Elastase levels were lower in case children at the time of the diagnosis of diabetes when compared to the control children. However, elastase concentrations did not differ between cases and controls at the time when autoantibodies appeared. Conclusion: The results suggest that the defect in the exocrine function develops after the appearance of islet autoantibodies. Further studies are needed to assess whether reduced elastase levels predict rapid progression of islet autoimmunity to clinical disease.Peer reviewe

Human enterovirus and rhinovirus infections are associated with otitis media in a prospective birth cohort study

BACKGROUND: Human enteroviruses (HEVs) and rhinoviruses (HRVs) have been linked to acute otitis media (AOM). OBJECTIVES:The present study evaluates the aforementioned association in a birth cohort setting. STUDY DESIGN: The cohort included 286 healthy infants (191 boys) followed from birth up to the age of 2 years in the Type 1 Diabetes Prediction and Prevention study in Finland. Stool samples were collected monthly and analyzed for the presence of HRV and HEV RNA using RT-PCR. Clinical symptoms were recorded by a questionnaire every 3-6 months. RESULTS:Altogether 610 AOM episodes were reported during the follow-up. 9.8% of the stool samples were positive for HRV and 6.8% for HEV. HRV positivity peaked at the age of 3-6 months declining gradually after this age, whereas HEV positivity peaked later, at the age of 12-24 months. The risk of AOM was increased in children who were HEV positive at least once at the age of 6-12 months (OR 2.2 [95%CI 1.1-4.2], P=0.023) or who were HRV positive at least once at the age of 18-24 months (OR 2.3 [95%CI 1.0-5.2], P=0.042). Having an older sibling, short breast-feeding and maternal smoking during pregnancy were also significantly associated with AOM. CONCLUSIONS: HRV and HEV infections are frequent during the first months of life. The observed trend for increased risk of AOM in HRV and HEV positive children is in line with the results from hospital series suggesting that these viruses may play an independent role in the pathogenesis of AOM. (C) 2016 Elsevier B.V. All rights reserved.Peer reviewe

No Association Between Ljungan Virus Seropositivity and the Beta-cell Damaging Process in the Finnish Type 1 Diabetes Prediction and Prevention Study Cohort

Background: Ljungan virus (LV) has not confirmed to associate with any human disease, but a possible connection with type 1 diabetes has been suggested. LV is a rodent-borne picornavirus that induces a diabetes-like condition in rodents. Approximately 30% of adults and 60% of children are seropositive in Finland. The Finnish Type 1 Diabetes Prediction and Prevention study enabled the use of very well characterized sample panels from children seroconverted to positivity for multiple islet autoantibodies during their prospective observation from birth; in addition, samples from age, sex, human leukocyte antigen (HLA), and residence area matched control children. Methods: We analyzed LV IgG seroprevalence in 102 case children (65 had also developed type 1 diabetes), in addition to nondiabetic control children. LV and human parechovirus (HPeV) immunofluorescence assays were used to analyze LV and HPeV-specific IgG from 102 plasma samples taken at the time of islet autoantibody appearance and from 204 samples from the matched control children. Results: Altogether 46.1% of the case and 50.7% of the control children were positive for LV IgG (odds ratio 0.8; 95% confidence interval, 0.47-1.36; P = 0.416) and 67.6% versus 79.8% were positive for HPeV IgG, respectively (odds ratio 0.49, 0.27-0.9, P = 0.023). Conclusions: Thus, no risk associations between LV or HPeV-specific IgG and islet autoimmunity were observed. However, a trend for significantly higher prevalence of HPeV antibodies in control children (P = 0.023) suggests a possible protective association of this virus with islet autoimmunity.Peer reviewe

Do Rural Second Homes Shape Commensal Microbiota of Urban Dwellers? : A Pilot Study among Urban Elderly in Finland

According to the hygiene and biodiversity hypotheses, increased hygiene levels and reduced contact with biodiversity can partially explain the high prevalence of immune-mediated diseases in developed countries. A disturbed commensal microbiota, especially in the gut, has been linked to multiple immune-mediated diseases. Previous studies imply that gut microbiota composition is associated with the everyday living environment and can be modified by increasing direct physical exposure to biodiverse materials. In this pilot study, the effects of rural-second-home tourism were investigated on the gut microbiota for the first time. Rural-second-home tourism, a popular form of outdoor recreation in Northern Europe, North America, and Russia, has the potential to alter the human microbiota by increasing exposure to nature and environmental microbes. The hypotheses were that the use of rural second homes is associated with differences in the gut microbiota and that the microbiota related to health benefits are more diverse or common among the rural-second-home users. Based on 16S rRNA Illumina MiSeq sequencing of stool samples from 10 urban elderly having access and 15 lacking access to a rural second home, the first hypothesis was supported: the use of rural second homes was found to be associated with lower gut microbiota diversity and RIG-I-like receptor signaling pathway levels. The second hypothesis was not supported: health-related microbiota were not more diverse or common among the second-home users. The current study encourages further research on the possible health outcomes or causes of the observed microbiological differences. Activities and diet during second-home visits, standard of equipment, surrounding environment, and length of the visits are all postulated to play a role in determining the effects of rural-second-home tourism on the gut microbiota

Urbanization reduces transfer of diverse environmental microbiota indoors

Expanding urbanization is a major factor behind rapidly declining biodiversity. It has been proposed that in urbanized societies, the rarity of contact with diverse environmental microbiota negatively impacts immune function and ultimately increases the risk for allergies and other immune-mediated disorders. Surprisingly, the basic assumption that urbanization reduces exposure to environmental microbiota and its transfer indoors has rarely been examined. We investigated if the land use type around Finnish homes affects the diversity, richness, and abundance of bacterial communities indoors. Debris deposited on standardized doormats was collected in 30 rural and 26 urban households in and near the city of Lahti, Finland, in August 2015. Debris was weighed, bacterial community composition determined by high throughput sequencing of bacterial 16S ribosomal RNA (rRNA) gene on the Illumina MiSeq platform, and the percentage of four different land use types (i.e., built area, forest, transitional, and open area) within 200 m and 2000 m radiuses from each household was characterized. The quantity of doormat debris was inversely correlated with coverage of built area. The diversity of total bacterial, Proteobacterial, Actinobacterial, Bacteroidetes, and Firmicutes communities decreased as the percentage of built area increased. Their richness followed the same pattern except for Firmicutes for which no association was observed. The relative abundance of Proteobacteria and particularly Gammaproteobacteria increased, whereas that of Actinobacteria decreased with increasing built area. Neither Phylum Firmicutes nor Bacteroidetes varied with coverage of built area. Additionally, the relative abundance of potentially pathogenic bacterial families and genera increased as the percentage of built area increased. Interestingly, having domestic animals (including pets) only altered the association between the richness of Gammaproteobacteria and diversity of Firmicutes with the built area coverage suggesting that animal ownership minimally affects transfer of environmental microbiota indoors from the living environment. These results support the hypothesis that people living in densely built areas are less exposed to diverse environmental microbiota than people living in more sparsely built areas.Peer reviewe