An evaluation of strontium chloride, Rappaport and strontium selenite enrichment for the isolation of salmonellas from man, animals, meat products and abattoir effluents

Abstract

Strontium chloride enrichment broth was found to be comparable to Rappaport broth for the recovery of a wide range of Salmonella serotypes from man, animals, meat products and effluents. With the exception of cloacal samples from reptiles, both procedures were superior to selenite F.The performance of strontium chloride Mand selenite F enrichment was improved when effluent samples were incubated at 43 degrees C.Strontium chloride M and Rappaport enrichment were superior to selenite F for the isolation of Arizona species from reptiles.Strontium chloride B, strontium selenite and Rappaport broths were found suitable for the isolation of multiple Salmonella serotypes from sea water contaminated with abattoir effluents. The strontium chloride B and strontium selenite enrichment media were superior to Rappaport broth when samples were incubated at 43 degrees C.Modified bismuth sulphite agar was found superior to Salmonella-Shigella agar as a solid subculture medium.The investigation of a food poisoning outbreak due to Salmonella typhimurium phage type 21 is reported.The significance of the choice of sampling and isolation techniques in salmonellosis in man and animals is discussed.

Enrichment procedures for the isolation of Salmonella, Arizona, Edwardsiella and Shigella from faeces

“…The strontium selenite and strontium chloride M broths were prepared as reported by Iveson & Mackay-Scollay (1972). Gram-negative broth (B.B.L.)…”

“…With the exception of S. typhi, Rappaport broth has been superior to both selenite F and tetrathionate for the isolation of Salmonella (Collard & Unwin, 1958;Iveson, Kovacs & Laurie, 1964;Hooper & Jenkins, 1965;Iveson & Kovacs, 1967;Iveson & Mackay-Scollay, 1969, 1972. However, the method was found unsuitable for the isolation of S. dublin and S. pullorum from animals and was not suited to the elevated temperature of incubation (Harvey & Price, 1968).…”

“…In further investigations it was show-n that the selective qualities of strontium chloride M broth were only slightly reduced when the malachite green dye was omitted, furthermore the modified medium (strontium chloride B broth) was found suitable for the isolation of Edwardsiella tarda, as well as Salmonella and Arizona bacteria (Iveson, 1971). The medium was well suited to the elevated temperature technique, and multiple salmonella serotypes were recovered from abattoir effluents using strontium chloride B broth incubated at 430 C. (Iveson & Mackay-Scollay, 1972).…”

“…Strontium hydrogen selenite and strontium chloride have been found effective as selective ingredients in Salmonella enrichment media (Iveson & MackayScollay, 1969, 1972. In comparative tests, strontium chloride malachite green broth (strontium chloride M) was found suitable for the isolation of salmonellas from human and animal faeces, foodstuffs, meat processing and abattoir effluents.…”

A Comparison of Strontium Chloride M Broth, and Mannitol, Selenite, Cystine Broth in the Isolation of Salmonellae From Egg Products

“…A strontium chloride M enrichment broth has been described, (Iveson, 1971,' Iveson and Mackay-Scollay, 1969, 1972. The study reported here compares its efficiency with that of mannitol, selenite, cystine broth.…”