Template-Type: ReDIF-Article 1.0 Author-Name: J. Osek Author-Workplace-Name: Department of Microbiology, National Veterinary Research Institute (PIWet), Pulawy, Poland Author-Name: P. Gallien Author-Workplace-Name: Department of Microbiology, National Veterinary Research Institute (PIWet), Pulawy, Poland Title: Molecular analysis of Escherichia coli O157 strains isolated from cattle and pigs by the use of PCR and pulsed-field gel electrophoresis methods Abstract: Fourteen Escherichia coli O157 strains isolated from cattle and pigs in Poland and in Germany were investigated, using PCR, for the genetic markers associated with Shiga toxin-producing E. coli (STEC). Only two strains, both of cattle origin, were positive for the fliC (H7) gene and could be classified as O157 : H7. Nine isolates had stx shiga toxin genes, either stx1 (1 strain), stx2 (4 isolates) or both (4 strains). The stx2-carrying samples were further subtyped by PCR for the stx2c, stx2d, and stx2e toxin variants. It was shown that all but one stx2-positive bacteria possessed the stx2c Shiga toxin gene type and one stx2 STEC isolate had the stx2d virulence factor sub-type. The eaeA (intimin) gene was found in 9 strains (8 isolates from cattle and one strain from pigs); all of them harboured the genetic marker characteristic of the gamma intimin variant. The translocated intimin receptor (tir) gene was detected in 7 isolates tested and among them only one tir-positive strain was recovered from pigs. The ehly E. coli enterohemolysin gene was amplified in all but one strains obtained from cattle and only in one isolate of porcine origin. The genetic relatedness of the analysed E. coli O157 strains was examined by restriction fragment length polymorphism (RFLP) of chromosomal DNA digested with XbaI. Two distinct but related RFLP pattern clusters were observed: one with 9 strains (8 isolates of bovine origin and one strain obtained from pigs) and the other one comprises the remaining 5 E. coli isolates (4 of porcine origin and one strain recovered from cattle). The results suggest that pigs, besides cattle, may be a reservoir of E. coli O157 strains potentially pathogenic to humans. Moreover, epidemiologically unrelated isolates of the O157 serogroup, recovered from different animal species, showed a clonal relationship as demonstrated by the RFLP analysis. Keywords: E. coli O157, cattle, pigs, virulence marker genes, RFLP, genetic relatedness Journal: Veterinární medicína Pages: 149-158 Volume: 47 Issue: 6 Year: 2002 DOI: 10.17221/5819-VETMED File-URL: http://vetmed.agriculturejournals.cz/doi/10.17221/5819-VETMED.html File-Format: text/html X-File-Ref: http://agriculturejournals.cz/RePEc/caa/references/vet-200206-0001.txt Handle: RePEc:caa:jnlvet:v:47:y:2002:i:6:id:5819-VETMED Template-Type: ReDIF-Article 1.0 Author-Name: R. Ulrich Author-Workplace-Name: Veterinary Research Institute, Brno, Czech Republic Author-Name: J. Raszyk Author-Workplace-Name: Veterinary Research Institute, Brno, Czech Republic Title: Variations in environmental contamination by polychlorinated biphenyls (PCB) and chlorinated pesticides (Lindane, DDT) on ping farms in Hodonín district in 1994 to 1999 Abstract: Environmental samples (n = 216) were collected at regular intervals from 1994 to 1999 on three pig farms (D., M., T.) in the area of the district town of Hodonín, Czech Republic. The samples of feed mixtures (n = 85), drinking water (n = 44), barn dust sediments (n = 45), and muscular tissue of feeder pigs (n = 42) were analysed for the concentrations of PCB (sum of 7 indicator congeners), DDT (sum of 6 isomers), and lindane (g-hexachlorocyclohexane). The concentrations of lindane showed increasing tendencies in feed mixtures (1995-1999), drinking water (1997-1999), barn dust sediments (1996-1998), and pork (1997-1999). The limit of permissi-ble concentrations (hereinafter limit) was exceeded in two samples of feed mixtures collected in 1994. The limit for DDT was exceeded in two samples of feed mixtures collected in 1994. Generally, the concentrations showed a decreasing tendency in feed mixtures and barn dust sediments (1997-1999) and regular fluctuations in pork. The limit for PCB was exceeded in two samples of feed mixtures collected in 1994 and in one sample of drink-ing water collected in 1995. The concentrations showed increasing tendencies in feed mixtures (1995-1998) and pork (1996-1998). Decreasing tendencies were observed in drinking water (1995-1999) and barn dust sediments (1994-1997). Compared with mean values for the Czech Republic, the concentrations of lindane were higher in feed samples collected in 1994, 1997, and 1998, in drinking water samples collected in 1994 and 1995, and in pork samples collected in 1994-1998, the concentrations of DDT were higher in feed samples collected in 1994, 1997, and 1998, drinking water samples collected in 1995, and pork samples collected in 1994 and 1996-1998, and the concentrations of PCB were higher in feed samples collected in 1997 and 1998, in drinking water samples collected in 1994 and 1995, and in pork samples collected in 1996-1998. The health risk of DDT, lindane, and PCB has been assessed as moderate, medium, and moderately increased, respectively. Keywords: pig farms, polychlorinated biphenyls, lindane, DDT, feed mixtures, drinking water, dust sediments, pork, sources, health Journal: Veterinární medicína Pages: 159-168 Volume: 47 Issue: 6 Year: 2002 DOI: 10.17221/5820-VETMED File-URL: http://vetmed.agriculturejournals.cz/doi/10.17221/5820-VETMED.html File-Format: text/html X-File-Ref: http://agriculturejournals.cz/RePEc/caa/references/vet-200206-0002.txt Handle: RePEc:caa:jnlvet:v:47:y:2002:i:6:id:5820-VETMED Template-Type: ReDIF-Article 1.0 Author-Name: R. Herich Author-Workplace-Name: Department of Pathology, University of Veterinary Medicine, Košice, Slovak Republic Author-Name: M. Levkut Author-Workplace-Name: Department of Pathology, University of Veterinary Medicine, Košice, Slovak Republic Title: Lactic acid bacteria, probiotics and immune system Abstract: Mucous membranes of the body are in direct contact with the outside environment and they are colonised by a large number of different bacteria. Through mucous membranes, the organism is in permanent con-tact with different antigens. Mucous surfaces are protected by many defence mechanisms that ensure a permanent and effective protection. They include the production of secretory IgA, the production of mucus, cytoprotective peptides, defensins etc. Indigenous microflora markedly affects the structure of the host mucous, its function, and the development of the whole immune system. Protective microflora prevents pathogens from adhering by competi-tion for substrates and places of adhesion, and they simultaneously produce antibacterial substances and stimulate the production of specific antibodies and mucus. The early colonisation of the gut with living micro-organisms is important for the development of the gut protection barrier. The number of immune and epithelial cells increases. Probiotic micro-organisms including lactic acid bacteria (LAB) positively influence the composition of the gut microflora; they stimulate the production of secretory IgA; they affect the targeted transportation of the luminal antigens to Peyer's patches and they increase the production of IFN-g. LAB stimulate the activity of non-specific and specific immune cells. These properties of the LAB depend on the particular species or strain of bacteria. These singularities are probably determined by differences in the cell wall composition. LAB belong to a group of benefi-cially acting bacteria and they are able to eliminate damage to the gut microenvironment; they stimulate local and systemic immune responses and they maintain the integrity of the gut wall. Keywords: lactic acid bacteria, gut, mucous layer, immunity Journal: Veterinární medicína Pages: 169-180 Volume: 47 Issue: 6 Year: 2002 DOI: 10.17221/5821-VETMED File-URL: http://vetmed.agriculturejournals.cz/doi/10.17221/5821-VETMED.html File-Format: text/html X-File-Ref: http://agriculturejournals.cz/RePEc/caa/references/vet-200206-0003.txt Handle: RePEc:caa:jnlvet:v:47:y:2002:i:6:id:5821-VETMED