Leptospirosis. The waters from the swine farm as vehicles of Leptospira, at the central coffee growers area of Colombia

Abstract

This work was carried out at fifteen swine farms of the central coffee growers area where the presence of leptospiras was confirmed in the existing water sources. Two hundred and ninety two samples of drinking water were taken and 20.5% (60/292) were positive by direct microscopic examination; while 66% (31/47) were positive from forty seven samples of sewage,. The order of importance, concerning the proportional contamination rate was: sewage, water deposits, nipples, and washing water tank. The positiveness of leptospira cultures was as follows: drinking and pen washing water 14.2%; and sewage 9.3%. The highest proportional contamination rate by leptospira in drinking and washing water, was shown by deposit tanks and the nipples. The wasted waters had a high positiveness by dark field examination, but a low positiveness in cultivation. On the other hand, the 17 strains obtained in this study, as well as the 7 reference antigens: pomona, icterohaemorragiae, grippotyphosa, canícola, bratislava, hardjobovis from the, interrogans species; and hardjopratjino from the borgpetersenii species, which were reacted in the MAT with sera from 68 hogs of the swine farms, yielded a negative result. Finally, the 17 strains obtained could not be classified as interrogans or biflexa therefore, they might be intermediate Leptospiras between saprophytes and pathogens. The 17 strains were subjected to biological assays, as the ability to grow in the presence of 225 µg/ml of Azaguanine at 13ºC; change to spherical cells with NaCl 1M, and growth in TSB. The reactions did not indicate whether the isolates belonged to L. biflexa or to L. interrogans. The cultivations in TSB did not show growing therefore, the strains might be leptospiras between saprofites and pathogens, due to the growth obtained at 13, 28 and 30ºC.