Saturday, 15 July 2006

Occurrence of C. perfringens from Different Cultivated Soil.

Crisa Voidarou1, Sotirios Kandrelis1, Dimitrios Vassos2, Athina Tzora1, Ioannis Skoufos1, Athanasios Alexopoulos3, and Eygenia Bezirtzoglou3. (1) T.E.I. of Epirus, Laboratory of Animal Health and Infections Diseases, Dept of Animal Production, E. Venizeloy 5, Arta, Greece, (2) Univ of Ioannina, Medical School, Hygiene Lab, 45110, E. Venizeloy 5, Arta, Greece, (3) Democritus Univ of Thrace, School of Agricultural Development, Microbiology Lab, Orestriada 175, 68200, Orestiada, Greece

The recent increased knowledge of anaerobic bacteria, their occurrence, cultivation and identification has raised the question of their role in the different types of cultivated soils. Among the anaerobes species our interest is focused on C.perfringens which is widely distributed in nature and is naturally present in large numbers in the soil, sewage , and in the human and animal intestinal tract, where it occurs in both the vegetative and spore forms. 750 samples from cultivated soil were collected, coming from the North Quest area of Greece. Our samples consist of cultivated soil dedicated to the production of the following products; Three different types of cultures were considered on the present study; bulb bearing undersurface of the soil, bulb bearing on the soil, bulb bearing out of the soil surface. Brawwica oderacea (vegetable), Olive, Daucus carota (carrot), Solanum tuberosum (potato), Phaseolus vulgaris (green haricot), Beta vulgaris var. rapaceum (beetroot), Cucurbita pepo (squash), Allium cepa (onion), Cucumis sativus (cucumber) and Capsicum annum (pepper). Membrane filtration equipment was used. All samples were alternatively passed through two membrane filters, the first (20 ėm pore size) was used for retention of the soil impurities and the second (porosity 0,45 ėm) for C.perfringens. The growth medium used was lactase – sulphite (L.S. broth). All isolated C.perfringens strains were tested for their antimicrobial activities by the amoxicillin (25ėgr), penicillin G ( 10 units), kanamycin (30 ėgr), tetracycline (30gr), streptomycin (10 ėgr), erythromycin (15 ėgr) ęáé chloramphenicol (30 ėgr). When considering together the type of the bulb production; it was observed increased number of C.perfringens spore densities in the most undersurface bulb production soils. Moreover, C.perfringens spore are likely to occur in particularly large numbers in soil contaminate by fecal matter. Additionally, there is a close relationship between the amount of pollution and presence of C.perfringens. Most of our strains showed resistance to the above antibiotics applied usually for human and veterinary care. It is then conceivable that the presence of C.perfringens as bacterial indicator depend not only on physicochemical conditions, but it is mainly associated with the nature of the organic pollution. It is then conceivable that systematic monitoring of the cultivated soil ecosystems must include bacteriological parameters together with chemical indices of organic pollution in order to obtain information adequate for assessing their overall quality from the point of view of public health.

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