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Wyświetlanie 1-15 z 118
Tytuł:
Cathelicidin influence on pathological activation of Wnt pathway in murine model of hypersensitivity pneumonitis
Autorzy:
Lemieszek, M.K.
Golec, M.
Zwoliński, J.
Dutkiewicz, J.
Milanowski, J.
Powiązania:
https://bibliotekanauki.pl/articles/28761763.pdf
Data publikacji:
2022
Wydawca:
Instytut Medycyny Wsi
Źródło:
Annals of Agricultural and Environmental Medicine; 2022, 29, 3; 358-364
1232-1966
Pojawia się w:
Annals of Agricultural and Environmental Medicine
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Mycobiota and mycotoxins in various kinds of vegetables and fruits as potential health risk factors for consumers – summary of a multiyear study
Autorzy:
Kłapeć, T.
Wójcik-Fatla, A.
Farian, E.
Kowalczyk, K.
Cholewa, G.
Cholewa, A.
Dutkiewicz, J.
Powiązania:
https://bibliotekanauki.pl/articles/28761819.pdf
Data publikacji:
2022
Wydawca:
Instytut Medycyny Wsi
Źródło:
Annals of Agricultural and Environmental Medicine; 2022, 29, 2; 316-320
1232-1966
Pojawia się w:
Annals of Agricultural and Environmental Medicine
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Mycobiota of berry fruits - levels of filamentous fungi and mycotoxins, composition of fungi, and analysis of potential health risk for consumers
Autorzy:
Kłapeć, T.
Wójcik-Fatla, A.
Farian, E.
Kowalczyk, K.
Cholewa, G.
Cholewa, A.
Dutkiewicz, J.
Powiązania:
https://bibliotekanauki.pl/articles/28761878.pdf
Data publikacji:
2022
Wydawca:
Instytut Medycyny Wsi
Źródło:
Annals of Agricultural and Environmental Medicine; 2022, 29, 1; 28-37
1232-1966
Pojawia się w:
Annals of Agricultural and Environmental Medicine
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
COVID 19 – Possible interrelations with respiratory comorbidities caused by occupational exposure to various hazardous bioaerosols. Part II. Clinical course, diagnostics, treatment and prevention
Autorzy:
Mackiewicz, B.
Lemieszek, B.K.
Dutkiewicz, J.
Powiązania:
https://bibliotekanauki.pl/articles/28762850.pdf
Data publikacji:
2021
Wydawca:
Instytut Medycyny Wsi
Źródło:
Annals of Agricultural and Environmental Medicine; 2021, 28, 1; 27-43
1232-1966
Pojawia się w:
Annals of Agricultural and Environmental Medicine
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Levels of filamentous fungi and selected mycotoxins in leafy and fruit vegetables and analysis of their potential health risk for consumers
Autorzy:
Kłapeć, T.
Wójcik-Fatla, A.
Farian, E.
Kowalczyk, K.
Cholewa, G.
Cholewa, A.
Dutkiewicz, J.
Powiązania:
https://bibliotekanauki.pl/articles/28762517.pdf
Data publikacji:
2021
Wydawca:
Instytut Medycyny Wsi
Źródło:
Annals of Agricultural and Environmental Medicine; 2021, 28, 4; 585-594
1232-1966
Pojawia się w:
Annals of Agricultural and Environmental Medicine
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
COVID 19 – Possible interrelations with respiratory comorbidities caused by occupational exposure to various hazardous bioaerosols. Part I. Occurrence, epidemiology and presumed origin of the pandemic
Autorzy:
Dutkiewicz, J.
Mackiewicz, B.
Lemieszek, M.K.
Powiązania:
https://bibliotekanauki.pl/articles/28762975.pdf
Data publikacji:
2020
Wydawca:
Instytut Medycyny Wsi
Źródło:
Annals of Agricultural and Environmental Medicine; 2020, 27, 4; 491-504
1232-1966
Pojawia się w:
Annals of Agricultural and Environmental Medicine
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Potential sources of infection with selected zoonotic agents in the veterinary work environment - pilot studies
Autorzy:
Wójcik-Fatla, A.
Sroka, J.
Zając, V.
Sawczyn-Domańska, A.
Kloc, A.
Zwoliński, J.
Kłapeć, T.
Studzińska, M.B.
Chmura, R.
Dutkiewicz, J.
Powiązania:
https://bibliotekanauki.pl/articles/2085448.pdf
Data publikacji:
2020
Wydawca:
Instytut Medycyny Wsi
Tematy:
environment
Coxiella burnetii
Toxoplasma gondii
veterinarians
Leptospira spp
Cryptosporidium spp
Giardia duodenalis
Opis:
Introduction and Objective. The problem of occupational biohazards is very important, especially in the field of agriculture and in human and veterinary medicine. The aim of the study was to determine the potential sources of infection in veterinary professionals with selected zoonotic agents, including: Toxoplasma gondii, Giardia duodenalis, Leptospira spp., Cryptosporidium spp. and Coxiella burnetii. Materials and Method. A total of 50 air samples from barns, piggeries and veterinary surgeries were examined for the presence of Leptospira spp. and C. burnetii DNA. Serum samples of 86 pigs and 80 cows were tested for the presence of antibodies to Leptospira spp. and to phase I and II C. burnetii antigens. Serum of 70 cats were tested for the presence of antibodies to T. gondii and 65 samples of cat faeces for the presence of T. gondii oocysts. The presence of G. duodenalis and Cryptosporidium spp. were examined in 50 of dog faeces and 50 of bovine faeces samples. Results. DNA of Leptospira spp. was detected in 2 air samples from the piggeries (4%). C. burnetii DNA was not found in any sample. Anti-Leptospira spp. antibodies were detected in 51 (59.3%) of examined pigs. Neither anti-Leptospira spp. nor anti-C. burnetii antibodies were found among samples of bovine serum. Anti-T. gondii antibodies was found in 52 cat serum samples (74.3%). Among samples of cat faeces, no T. gondii oocysts were detected. In one sample of cattle stool (2%), G. duodenalis was detected and in another (2%) – Cryptosporidium spp. G. duodenalis was detected in 7 samples (14%) and Cryptosporidium spp. in 2 samples (2%) of dog faeces. Conclusions. The results of this study demonstrate the potential risk of infection with Leptospira spp. in veterinarians working with pigs. Veterinarians could be also be at risk of infection with T. gondii and G. duodenalis.
Źródło:
Annals of Agricultural and Environmental Medicine; 2020, 27, 1; 146-150
1232-1966
Pojawia się w:
Annals of Agricultural and Environmental Medicine
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Acute hypersensitivity pneumonitis in woodworkers caused by inhalation of birch dust contaminated with Pantoea agglomerans and Microbacterium barkeri
Autorzy:
Mackiewicz, B.
Dutkiewicz, J.
Siwiec, J.
Kucharczyk, T.
Siek, E.
Wójcik-Fatla, A.
Cholewa, G.
Cholewa, A.
Paściak, M.
Pawlik, K.
Szponar, B.
Milanowski, J.
Powiązania:
https://bibliotekanauki.pl/articles/2085105.pdf
Data publikacji:
2019
Wydawca:
Instytut Medycyny Wsi
Tematy:
hypersensitivity pneumonitis
wood dust
bacteria
Pantoea agglomerans
Microbacterium barkeri
inhalation challenge
occupational exposure
Opis:
Case description. Five workers (2 males and 3 females) employed in a furniture factory located in eastern Poland developed hypersensitivity pneumonitis (HP) after the pine wood used for furniture production was replaced by birch wood. All of them reported onset of respiratory and general symptoms (cough, shortness of breath, general malaise) after inhalation exposure to birch dust, showed crackles at auscultation, ground-glass attenuations in HRCT examination, and lymphocytosis in the BAL examination. The diagnosis of acute HP was set in 4 persons and the diagnosis of subacute HP in one. Identification of specific allergen. Samples of birch wood associated with evoking disease symptoms were subjected to microbiological analysis with the conventional and molecular methods. Two bacterial isolates were found to occur in large quantities (of the order 108 CFU/g) in examined samples: Gram-negative bacterium of the species Pantoea agglomerans and a non-filamentous Gram-positive actinobacterium of the species Microbacterium barkeri. In the test for inhibition of leukocyte migration, 4 out of 5 examined patients showed a positive reaction in the presence of P. agglomerans and 2 in the presence of M. barkeri. Only one person showed the presence of precipitins to P. agglomerans and none to M. barkeri. In the inhalation challenge, which is the most relevant allergological test in the HP diagnostics, all patients reacted positively to P. agglomerans and only one to M. barkeri. The results indicate that P. agglomerans developing in birch wood was the main agent causing HP in the workers exposed to the inhalation of dust from this wood, while the etiologic role of M. barkeri is probably secondary. Conclusion. The results demonstrate that apart from fungi and filamentous actinobacteria, regarded until recently as causative agents of HP in woodworkers, Gram-negative bacteria and non-filamentous actinobacteria may also elicit disease symptoms in the workers processing wood infected with large amounts of these microorganisms. The results obtained also seem to indicate that cellular-mediated reactions are more significant for causing disease symptoms compared to those that are precipitin-mediated.
Źródło:
Annals of Agricultural and Environmental Medicine; 2019, 26, 4; 644-655
1232-1966
Pojawia się w:
Annals of Agricultural and Environmental Medicine
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
The Evolution of Microstructure and Magneto-structural Properties of Heat Treated Ni-Mn-Sn-In Heusler Alloys Sintered by Vacuum Hot Pressing
Autorzy:
Maziarz, W.
Wójcik, A.
Chulist, R.
Szczerba, M. J.
Kowalczyk, M.
Czaja, P.
Cesari, E.
Dutkiewicz, J.
Powiązania:
https://bibliotekanauki.pl/articles/947530.pdf
Data publikacji:
2019
Wydawca:
Polska Akademia Nauk. Czytelnia Czasopism PAN
Tematy:
Ni-Mn-Sn metamagnetic shape memory alloys
sintering process
heat treatment
electron microscopy
Opis:
In this work, vacuum hot pressed Ni-Mn-Sn-In Heusler alloys with different concentration of In (0, 2 and 4 at.%), were investigated. The magneto-structural behaviour and microstructure dependencies on chemical composition and on heat treatment were examined. It was found that the martensite start transformation temperature increases with growing In content and to a lesser extent with increasing temperature of heat treatment. The high energy X-ray synchrotron radiation results, demonstrated that both chemical composition as well as temperature of heat treatment slightly modified the crystal structures of the studied alloys. Microstructural investigation performed by transmission electron microscopy confirmed chemical composition and crystal structure changes in the alloys.
Źródło:
Archives of Metallurgy and Materials; 2019, 64, 2; 727-732
1733-3490
Pojawia się w:
Archives of Metallurgy and Materials
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Toxoplasma gondii infection in selected species of free-living animals in Poland
Autorzy:
Sroka, J.
Karamon, J.
Wójcik-Fatla, A.
Dutkiewicz, J.
Bilska-Zając, E.
Zając, V.
Piotrowska, W.
Cencek, T.
Powiązania:
https://bibliotekanauki.pl/articles/2085130.pdf
Data publikacji:
2019
Wydawca:
Instytut Medycyny Wsi
Tematy:
Polska
Toxoplasma gondii
nested PCR
genotyping
free-living animals
Opis:
Introduction and objective. Free-living animals can play an important role as a reservoir of Toxoplasma gondi;, however, data concerning this issue in Poland are still limited.The aim of study was to assess the occurrence of T. gondii infection by using molecular methods in free-living animals in selected regions of Poland. Materials and method. Tissues samples of 396 animals (foxes, muskrats, birds, martens, badgers, polecats, raccoons, minks, raccoon dogs, otters, small rodents and insectivores, and grass snakes were collected from various regions of Poland. After samples digestion, DNA was isolated using QIAmp DNA Mini Kit (Qiagen). DNA extraction from small rodents and insectivores samples was performed without digestion. Next, nested PCR (B1 gene) and, for a part of nested PCR positive amplicons, RFLP PCR, were performed according to the method by Grigg and Boothroyd (2001). The other part of nested PCR positive DNA isolates were genotyped using 5 genetic markers: SAG1, SAG2 (5’- and 3’), SAG3, BTUB and GRA6, based on the method by Dubey et al. (2006). These PCR products were sequenced and compared with the NCBI database using Blast. Results. In total, in 50 of the 396 examined animals DNA of T. gondii was detected (12.6%). The highest percentages of positive results in PCR was obtained in martens (40.9%) and badgers (38.5%), lower in birds (27.3%) and the lowest in foxes (7.4%). The RFLP and multilocus PCR analysis showed the dominance of T. gondii clonal type II (or II/III). Conclusions. The results of this study indicate the frequent T. gondii infection among free-living animals in Poland, especially martens and badgers, which may indirectly indicate that these animals contribute to the spread of the parasite in the sylvatic environment in Poland. The genotyping analysis showed the dominance of T. gondii clonal type II (or II/III).
Źródło:
Annals of Agricultural and Environmental Medicine; 2019, 26, 4; 656-660
1232-1966
Pojawia się w:
Annals of Agricultural and Environmental Medicine
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Fungal diversity of root vegetables and soil rhizosphere collected from organic and conventional farms in Eastern Poland
Autorzy:
Kłapeć, T.
Cholewa, G.
Cholewa, A.
Dutkiewicz, J.
Wójcik-Fatla, A.
Powiązania:
https://bibliotekanauki.pl/articles/2081696.pdf
Data publikacji:
2018
Wydawca:
Instytut Medycyny Wsi
Tematy:
filamentous fungi
vegetables
rhizosphere soil
organic and conventional farms
Opis:
Objective. Determination of the concentration and species composition of filamentous fungi in root vegetables (carrots and red beetroots), and the adjacent rhizosphere soil, collected on organic and conventional farms in Eastern Poland. Materials and method. During the period 2015–2016, a total number of 80 samples of vegetables and 40 samples of soil were examined. From each type of farm, 20 samples of vegetables and 20 samples of the adjacent soil were examined. In addition, the study included 20 samples of vegetables from organic farms and 20 samples of vegetables from conventional farms purchased on the markets in the city of Lublin in Eastern Poland. In order to determine the concentration and species composition of filamentous fungi, both in vegetables and soil, the method of plate dilutions on Malt Agar medium (Difco) with chloramphenicol was used. The study was conducted in two parallel repetitions. Inoculated media were incubated at the temperature of 30° C for 72 hours, then at room temperature for 72 hours. The species composition of fungal flora was determined using macroscopic and microscopic methods, with the help of keys and atlases. Results. It was found that the mean concentration of fungi was higher in vegetables and soil from conventional farms than in those from organic farms. In the case of carrots and soil from conventional farms, this concentration was 4.93 and 5.10 log10 CFU g-1, respectively, whereas from organic farms – respectively, 3.81 and 4.20 log10 CFU g-1. In the case of beetroots and soil from conventional farms, the mean concentrations were also higher compared to organic farms – 5.09 vs. 3.93 and 4.95 vs. 4.23 log10 CFU g-1. In the examined vegetables and rhizosphere soil, 61 species of filamentous fungi were found, of which 12 belonged to the genus Penicillium, 4 to the genus Fusarium, and 2 species each to the genera: Aspergillus, Cladosporium and Trichoderma. As many as 28 (45.9%) fungal species that occurred in vegetables and soil are regarded as pathogenic for humans.
Źródło:
Annals of Agricultural and Environmental Medicine; 2018, 25, 2; 374-381
1232-1966
Pojawia się w:
Annals of Agricultural and Environmental Medicine
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Microstructure and Texture Changes of MgLiAl Alloys Composed of α or α + β Phases after Twist Channel Angular Pressing TCAP
Autorzy:
Dutkiewicz, J.
Rusz, S.
Kuc, D.
Hilser, O.
Bobrowski, P.
Kania, B.
Powiązania:
https://bibliotekanauki.pl/articles/356161.pdf
Data publikacji:
2018
Wydawca:
Polska Akademia Nauk. Czytelnia Czasopism PAN
Tematy:
MgLiAl alloys
twist channel angular pressing
TCAP
texture after TCAP
Li2MgAl precipitates
Opis:
Two MgLiAl alloys of composition 4.5% Li and 1.5% Al (in wt.%) composed of α phase and of 9% Li, 1.5% Al composed of α (hcp) + β (bcc) phases were subjected to twist channel angular pressing (TCAP) deformation. Such deformation of α + β alloys caused less effective grain refinement than that of single α phase alloy. However, with increasing number of passes, grain size of single α phase alloy increased and that of β phase in two phase α + β alloy also grew, which suggested the effect of dynamic recrystallization. TEM studies allowed identifying particles of Li2MgAl phase of size of few μm. {001}<100> texture was observed in extruded alloy. Texture studies of extruded and TCAPed single phase hcp alloy indicated texture with {1010} plane perpendicular to the extrusion direction and {0002} plane parallel to the extrusion direction. Duplex α + β alloys showed poor texture development.
Źródło:
Archives of Metallurgy and Materials; 2018, 63, 4; 1827-1835
1733-3490
Pojawia się w:
Archives of Metallurgy and Materials
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Optimization of flotation, DNA extraction and PCR methods for detection of Toxoplasma gondii oocysts in cat faeces
Autorzy:
Sroka, J.
Karamon, J.
Dutkiewicz, J.
Wójcik-Fatla, A.
Cencek, T.
Powiązania:
https://bibliotekanauki.pl/articles/2081971.pdf
Data publikacji:
2018
Wydawca:
Instytut Medycyny Wsi
Tematy:
flotation
Toxoplasma gondii
faeces
Real time PCR
nested PCR
cats
oocysts detection
Opis:
Introduction and objective. The aim of the study was to compare the effectiveness of selected oocysts concentration methods, DNA extraction protocols and PCR assays targeting the B1 gene, for the development of procedures which would be effective and useful in laboratory practice for the detection of T. gondii in faecal samples from cats. Materials and method. In order to compare the influence of the flotation fluids on microscopy and PCR detection of T. gondii, saturated solutions of saccharose, MgSO4, ZnSO4 and NaNO3 were used. To determine the sensitivity of PCR tests used: Real time PCR (RT) and nested PCR, water samples spiked with T. gondii tachyzoites and oocysts were tested. DNA was extracted using DNeasy Blood and Tissue Kit (Qiagen) (K1). The same PCR tests were used to assess the efficacy of T. gondii DNA detection in samples of cat faeces spiked with oocysts, using DNA extraction by a K1 set and a K2 set (QIamp DNA Stool Mini Kit, (Qiagen). Results. The initial results showed that NaNO3 was most useful as a flotation fluid due to the lack negative effect on the oocysts and amplification efficacy in PCR. The level of detection for water samples (100 μl) was determined as 100 tachyzoites and 1–50 oocysts in RT, and 2–20 oocysts in nested PCR. The limit of detection (LD) for stool samples (250 mg) spiked with oocysts, where the K1 set was used, determined as 250 and 5 oocysts in RT and nested PCR, respectively. For samples extracted with the K2 set, LD in RT was determined as 1–50 oocysts (depending on the variant) and 50 oocysts in nested PCR. Conclusions. The most effective methods for detection of T. gondii in cat faeces seem to be centrifugal flotation with NaNO3, followed by DNA extraction with removing of inhibitors (K2 set) and Real Time PCR targeting B1 gene.
Źródło:
Annals of Agricultural and Environmental Medicine; 2018, 25, 4; 680-685
1232-1966
Pojawia się w:
Annals of Agricultural and Environmental Medicine
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Prevalence of Toxoplasma gondii infection in cats in southwestern Poland
Autorzy:
Sroka, J.
Karamon, J.
Dutkiewicz, J.
Wójcik-Fatla, A.
Zając, V.
Cencek, T.
Powiązania:
https://bibliotekanauki.pl/articles/2081746.pdf
Data publikacji:
2018
Wydawca:
Instytut Medycyny Wsi
Tematy:
Polska
PCR
seroprevalence
Toxoplasma gondii
IFAT
cats
oocysts
coproscopy
Opis:
Objective. An assessment of the prevalence of Toxoplasma gondii infection in cats from southwestern Poland using serology, coproscopy and PCR methods. Materials and method. In total, 208 cats (139 females and 68 males), aged 0.5–12 years (mean=2.6) from 25 localities in southwestern Poland were examined by indirect immunofluorescence assay (IFAT) to estimate the T. gondii serological status. Faecal samples of 41 cats were examined for the presence of oocysts/DNA T. gondii by microscopy and Real-time/nested PCR. After flotation (with NaNO3), pellets from faecal samples were disrupted by 10 cycles of freezing (liquid nitrogen) and warming. DNA was extracted using QIamp DNA Stool Mini Kit (Qiagen), according to the manufacturer’s instruction. Results. The positive results in IFAT for anti-T. gondii IgG and IgM antibodies were found in 143 of 208 tested cats (68.8%). Among positive results, 14.5%, 34.1% and 51.4% were detected in titre ranges 128–512, 1,000–2,000 and ≥ 4,000, respectively. In 23.1% of cat sera anti- T. gondii IgM antibodies were found. The prevalence of anti-Toxoplasma antibodies was significantly greater in older cats (>1 year) (83.5%) than in younger cats (48.3%) (P<0.05), in females (74.1%) than in males (58.8%) (P<0.05), and in cats kept outdoors than indoors (69.7% vs. 16.7%) (P<0.01). Among the 41 faecal samples examined, the presence of structures resembling T. gondii oocysts was found in 2 samples (4.9%), and for one of these samples (2.4% of the total) the result was also confirmed by PCR. Conclusions. T. gondii infection in domestic cats is highly prevalent in southwestern Poland. Information on the prevalence of infection in cats can be useful for assessing T. gondii environmental contamination and the risk for public health.
Źródło:
Annals of Agricultural and Environmental Medicine; 2018, 25, 3; 1-5
1232-1966
Pojawia się w:
Annals of Agricultural and Environmental Medicine
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Streptococcus suis: a re-emerging pathogen associated with occupational exposure to pigs or pork products. Part II – pathogenesis
Autorzy:
Dutkiewicz, J.
Zając, V.
Sroka, J.
Wasiński, B.
Cisak, E.
Sawczyn, A.
Kloc, A.
Wojcik-Fatla, A.
Powiązania:
https://bibliotekanauki.pl/articles/2081593.pdf
Data publikacji:
2018
Wydawca:
Instytut Medycyny Wsi
Tematy:
Streptococcus suis
pathogenesis
infection stages
interaction with host cells and tissues
virulence factors
genomic
determinants of pathogenicity
biofilm formation
Opis:
Abstract Streptococcus suis is a re-emerging zoonotic pathogen that may cause severe disease, mostly meningitis, in pigs and in humans having occupational contact with pigs and pork, such as farmers, slaughterhose workers and butchers. The first stage of the pathogenic process, similar in pigs and humans, is adherence to and colonisation of mucosal and/or epithelial surface(s) of the host. The second stage is invasion into deeper tissue and extracellular translocation of bacterium in the bloodstream, either free in circulation or attached to the surface of monocytes. If S. suis present in blood fails to cause fatal septicaemia, it is able to progress into the third stage comprising penetration into host’s organs, mostly by crossing the blood-brain barrier and/or blood–cerebrospinal fluid barrier to gain access to the central nervous system (CNS) and cause meningitis. The fourth stage is inflammation that plays a key role in the pathogenesis of both systemic and CNS infections caused by S. suis. The pathogen may induce the overproduction of pro-inflammatory cytokines that cause septic shock and/or the recruitment and activation of different leukocyte populations, causing acute inflammation of the CNS. Streptococcus suis can also evoke – through activation of microglial cells, astrocytes and possibly other cell types – a fulminant inflammatory reaction of the brain which leads to intracranial complications, including brain oedema, increased intracranial pressure, cerebrovascular insults, and deafness, as a result of cochlear sepsis. In all stages of the pathogenic process, S. suis interacts with many types of immunocompetent host’s cells, such as polymorphonuclear leukocytes, mononuclear macrophages, lymphocytes, dendritic cells and microglia, using a range of versatile virulence factors for evasion of the innate and adaptive immune defence of the host, and for overcoming environmental stress. It is estimated that S. suis produces more than 100 different virulence factors that could be classified into 4 groups: surface components or secreted elements, enzymes, transcription factors or regulatory systems and transporter factors or secretion systems. A major virulence factor is capsular polysaccharide (CPS) that protects bacteria from phagocytosis. However, it hampers adhesion to and invasion of host’s cells, release of inflammatory cytokines and formation of the resistant biofilm which, in many cases, is vital for the persistence of bacteria. It has been demonstrated that the arising by mutation unencapsulated S. suis clones, which are more successful in penetration to and propagation within the host’s cells, may coexist in the organism of a single host together with those that are encapsulated. Both ‘complementary’ clones assist each other in the successful colonization of host’s tissues and persistence therein. S. suis has an open pan-genome characterized by a frequent gene transfer and a large diversity. Of the genetic determinants of S. suis pathogenicity, the most important are pathogenicity islands (PAI), in particular, a novel DNA segment of 89 kb length with evident pathogenic traits that has been designated as 89K PAI. It has been estimated that more than one-third of the S. suis virulence factors is associated with this PAI. It has been proved that the virulent S. suis strains possess smaller genomes, compared to avirulent ones, but more genes associated with virulence. Overall, the evolution of the species most probably aims towards increased pathogenicity, and hence the most significant task of the current research is an elaboration of a vaccine, efficient both for humans and pigs.
Źródło:
Annals of Agricultural and Environmental Medicine; 2018, 25, 1; 186-203
1232-1966
Pojawia się w:
Annals of Agricultural and Environmental Medicine
Dostawca treści:
Biblioteka Nauki
Artykuł
Wyświetlanie 1-15 z 118

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