[Isolation of new serovars of Salmonella in streams of water]

Abstract

The present work is the final stage of a research to determine the causes and degree of pollution of the Zaiman creek waters, which flow through the Capital District of Misiones, Argentina. The research was focused on the presence of Salmonella serovars in samples collected from 2 stream sites equidistant from a cold storage plant and slaughterhouse, one downstream, and the other before the source of pollution. Elevated temperature technique for the isolation of Salmonella was applied. The methodology consisted in applying an enrichment procedure for waterborne pathogens, performed by incubating after a convenient exposure period, gauze swabs in Dulcitol Selenite and Tetrationate (with the addition of 0,001% brilliant green) broths. Salmonella organisms were recovered by streaking duplicate plates of E.M.B Agar (Eosin Methylene Blue), B.P.L.S Agar (Brilliant Green Agar) and Bismuth Sulphite Agar. Best results were obtained when Bulcitol Selenite broth and Bismuth Sulphite Agar were used. (Tables 1, 2, 3). Suspected colonies were classified by 10 biochemical reactions, and further verified by serological identification. So far, 716 suspected colonies have been studied. Salmonella was isolated from 76% of the samples and 22 serovars were identified (Table 3). Isolating frequency of serovars during 1981-1984 is shown (Table 4). S. saphra prevailed among the studied samples, while both S. anatum and S. newport ranked second.(ABSTRACT TRUNCATED AT 250 WORDS)