Preferencje help
Widoczny [Schowaj] Abstrakt
Liczba wyników

Znaleziono wyników: 18

Liczba wyników na stronie
Pierwsza strona wyników Pięć stron wyników wstecz Poprzednia strona wyników Strona / 1 Następna strona wyników Pięć stron wyników wprzód Ostatnia strona wyników

Wyniki wyszukiwania

Wyszukiwano:
w słowach kluczowych:  leptospirosis
help Sortuj według:

help Ogranicz wyniki do:
Pierwsza strona wyników Pięć stron wyników wstecz Poprzednia strona wyników Strona / 1 Następna strona wyników Pięć stron wyników wprzód Ostatnia strona wyników
Leptospirosis is a widespread although recently neglected zoonosis recognized worldwide. The disease seems to be underestimated, especially in countries located in the temperate climatic zone. The presented article concerns the main characteristics of leptospirosis and describes formerly known and recently observed environmental, occupational and recreational risk factors significant in the spreading and pathogenesis of the disease. The aspects of epidemiology significant in the temperate climatic zone are emphasized. The majority of cited articles present cases of the disease reported from Europe or North America. Climatic changes (warming) and extreme weather events such as floods are potential risk factors of leptospirosis. Also, some socio-economic phenomena, such as the intensive migration of people resulting in the transfer of the infections acquired in tropical countries, or worsening of economic status in the cities, increase the probability of disease. Apart from the danger connected with rodents, which are the main vectors of leptospires, occurrence of the disease in dogs and cats can generate a higher risk of infection for humans. Infections may also be acquired during various types of agricultural work and during recreational activities, such as swimming. The results of recent investigations show that ticks are also potential vectors of leptospires. The more frequent emergence of leptospirosis in countries located in the temperate climatic zone emphasize the need to verify knowledge related to the risk of its appearance, and to consider this disease during diagnostic processes.
Leptospirosis, caused by pathogenic Leptospira, is one of the most important zoonoses in the world. Several molecular techniques have been developed for detection and differentiation between pathogenic and saprophytic Leptospira spp. The aim of this study was to develop a rapid and simple assay for specific detection and differentiation of pathogenic Leptospira spp. by multiplex real-time PCR (TaqMan) assay using primers and probes targeting Leptospira genus specific 16S ribosomal RNA gene, the pathogen specific ligA/B genes and non-pathogen Leptospira biflexa specific 23S ribosomal RNA gene. Sixteen reference strains of Leptospira spp. including pathogenic and nonpathogenic and ten other negative control bacterial strains were used in the study. While the 16S primers amplified target from both pathogenic and non-pathogenic leptospires, the ligA/B and the 23S primers amplified target DNA from pathogenic and non-pathogenic leptospires, respectively. The multiplex real-time PCR (TaqMan) assay detection limit, that is, the sensitivity was found approximately 1 x 10² cells/ml for ligA/B gene and 23S ribosomal RNA gene, and 10 cells/ml 16S ribosomal RNA. The reaction efficiencies were 83-105% with decision coefficients of more than 0.99 in all multiplex assays. The multiplex real-time PCR (TaqMan) assay yielded negative results with the ten other control bacteria. In conclusion, the developed multiplex real-time PCR (TaqMan) assay is highly useful for early diagnosis and differentiation between pathogenic and non-pathogenic leptospires in a reaction tube as having high sensitivity and specificity.
The aim of the study was to evaluate the prevalence of antibodies specific to different serogroups of Leptospira sp. in swine populations in Poland. The serological survey was conducted in 2006. A total of 7 252 swine serum samples coming from all provinces of the country were investigated. The samples were examined by the use of a microscopic agglutination test. As antigens, six Leptospira serovars were used: Leptospira interrogans serovars - Icterohaemorrhagiae, Pomona, and Canicola, L. borgpetersenii serovars - Sejroe and Tarassovi, and L. kirschneri serovar Grippotyphosa. Altogether, 97 (1.34%) of the examined serum samples were found to be positive. They were obtained from 12 provinces. The highest number of samples among positive sera demonstrated titres to serovar Sejroe (44.33%) followed by Pomona (37.11%), Icterohaemorrhagiae (8.25%), Canicola (7.22%), and Tarassovi (3.09%). No samples with titres to serovar Grippotyphosa were found. The data concerning the highness titres to particular serovars and the prevalence of animals demonstrating antibodies to different serovars in particular provinces are presented and analysed in the article.
Leptospirosis is a major zoonosis throughout the world. The disease can infect several mammal species of farming and domestic animals. The objective of this study was to investigate the prevalence of canine leptospirosis in a rural area of Thailand. One hundred and fifty three non-leptospira vaccinated dogs were selected from the Nakhon Pathom province of Thailand during April 2006 by simple random sampling. The signalment data of age, breed and sex were recorded. All serum samples were reacted with 24 references of leptospira serovars by microscopic agglutination test (MAT). The results showed the highest positivity in dogs aged within 3-6 years (P < 0.05) but were not significantly different between the genders. The most prevalent serovar was tarassovi (30.7%) and its titer ranged from 50 to 400. For all 88 MAT positive sera, 62.5% and 37.5% were positive with multiple and single leptospira serovars, respectively. The high disease prevalence in dogs indicates the high leptospira contamination in this area. However, the potential of the disease transmitted source in dogs is indefinite. Consequently, for effective disease eradication strategies, the local prevalence of leptospira serovars should be utilized for further vaccination.
Swine are one of significant reservoirs and sources of Leptospira infections for man. Serological screenings help to effectively control the epidemiological situation in swine herds and to prevent transmission of Leptospira from animals to man. The purpose of this study was to investigate, by the use of serological methods, the prevalence of infections caused by selected Leptospira serogroups in swine population in Poland. A total of 7112 swine serum samples were examined. The samples were collected from January to October 2008 and came from 280 counties situated in all 16 provinces of Poland. All sera were examined preliminary by enzyme-linked immunosorbent assay (ELISA) using heat-stable antigenic preparation. The samples positive or doubtful in ELISA were investigated by microscopic agglutination test (MAT) with use of serovars Icterohaemorrhagiae, Pomona, Canicola, Sejroe, Tarassovi and Grippotyphosa. Of the collected sera examined by ELISA 73 (1.02%) samples were positive, 85 (1.20%) – doubtful and 6954 – negative. Among ELISA-positive and doubtful sera 64 samples (coming from 14 provinces) were recognized in MAT as positive. Among MAT positive samples 42.19% of sera demonstrated titres with serovar Pomona, 32.81% – with Sejroe, 14.06% – with Icterohaemorrhagiae, 6.25% – with Tarassovi, 3.13% – with Grippotyphosa and 1.56% with Canicola.
Serology plays an important role in laboratory diagnosis of leptospirosis. Apart from the most often used microscopic agglutination test (MAT), enzyme-linked immunosorbent assay (ELISA) seems to be useful especially in screenings of animal herds. The ELISA used for detection of antibodies against selected Leptospira serogroups in swine serum samples was investigated during the study. An essential element of this test is heat-stable antigenic preparation from cultures of Leptospira interrogans serovars Icterohaemorrhagiae, Pomona and L. borgpetersenii serovar Sejroe. The aim of the present study was to identify and analyze ELISA heat-stable antigen fractions playing a role in the reaction with leptospiral antibodies indicated in swine serum. Reactivity of the three-component antigenic preparation was compared in immunoblotting with reactivity of six heat-stable antigenic preparations made from the following single serovars: L. interrogans serovars Icterohaemorrhagiae, Pomona, Canicola, L. borgpetersenii serovars Sejroe, Tarassovi and L. kirshneri serovar Grippotyphosa. All antigenic preparations were submitted to SDS-PAGE and transferred to a nitrocellulose membrane using a semidry system. After the transfer, the membrane was incubated with diluted swine serum containing antibodies specific for one of the six above mentioned Leptospira serovars. For the three-component antigenic preparation and antigens prepared from single serovars the immunoblot revealed reaction of sera with fractions of the 20-26 kDa region and around the 14.5 kDa region. The investigated heat-stable Leptospira antigenic preparation contains fractions demonstrating serogroup- and species-specificity. Fraction 20-26 kDa showed serogroup-specific activity, whereas the fraction around 14.5 kDa showed species-specific activity.
The purpose of the study was to suppress a known natural focus of fi eld fever exerting an infl uence on animal hosts of leptospires – small terrestrial mammals (s.t.m.) by rodenticide. After repeated application of the zinc phosphide rodenticide, the s.t.m. were regularly live-trapped and checked for leptospirosis by dark-fi eld microscopy and culture of their renal tissue and serological examination. Isolated leptospira strains were typed by help of rabbit factor sera. The deratization infl uenced the s.t.m. structure considerably: the proportion of the dominant Microtus arvalis subjects – the main reservoirs of Leptospira kirschneri serovar Grippotyphosa – were gradually and substantionally reduced and, contrarily, the percentage of the potetial hosts subjects – Clethrionomys glareolus and Apodemus fl avicollis – rose decisively over time. Changes in culture and serological positivity for leptospirosis of s.t.m. have also been enregistered. The highest original infestation of M. arvalis have slowly but strongly decreased while that of C. glareolus and A. fl avicollis has increased decisively and reached its maximum within the last years of investigation. It is probable that these two animal species have undertaken the leading role in the maintenance of the natural focus of the fi eld fever. In other animal species analogous trends were not registered. Based on these long-term fi ndings, there exists the possibility to suppress only partially and temporarily the epizootic process of leptospirosis in a natural focus that can be desirable in some circumstances (building or free time activities, etc.).
Pierwsza strona wyników Pięć stron wyników wstecz Poprzednia strona wyników Strona / 1 Następna strona wyników Pięć stron wyników wprzód Ostatnia strona wyników
JavaScript jest wyłączony w Twojej przeglądarce internetowej. Włącz go, a następnie odśwież stronę, aby móc w pełni z niej korzystać.