The Value of the Association Escherichieae‐group D Streptococci in the Diagnosis of Contamination in Foods

Abstract

The tests for faecal contamination in foods, based on 'indicator species', should be reconsidered for the following reasons. First, in Europe, Eschekhio coli is regarded BB a specific index of such contamination; but, apparently through the use of antibiotics, the proportion of human faeces containing Klebaielka has risen from 5.2% in 1947 to 48.4% in 1956-7. Moreover, E. coli and other coli-aerogenes organisms may be absent from the gut of certain animals, notably the pig. Second, while the usual methods of counting coli-aerogenes bacteria do not permit the isolation of strains which ferment lactose slowly or not at all (i.e. paracolons), these occur in 35.6% of samples of human faeces. Further, the recommended methods of detecting such strains are not wholly satisfactory. Third, the origin of the coli-aerogenes bacteria is uncertain.It is thus necessary to consider other organisms which normally inhabit the intestinal tract of humans and other animals. As to Clostridhn perfringenu, its source is doubtful, for it may come from faeces or from soil. and many foods contain only mil strains. The group D streptococci, on the other hand, are excellent indicators of faecal contamination. They are constant or frequent in the intestines of man and animals, and often more numerous there than coli-aerogenes bacteria. Their specificity as an index of faecal contamination is high and their investigation is easy with the selective media now available. Associated with the coli-aerogenes bacteria, they justify the diagnosis of faacal contamination in a foodstuff.

Influence of Temperature, NaCI, and pH on the Growth of Aeromonas Hydrophila

“…This bacterium can be readily isolated, often in considerable numbers, from various foods of animal origin, including beef (Ayres, 1960;Jay, 1967), pork (Blickstad and Molin, 1983;Enfors et al, 1979;Myers et al, 1982), raw milk (Kielwein et al, 1969;Kleeberger, 1975), and poultry (Nagel et al, 1960), as well as fish (Molin and Stenstrom, 1984;Boulander et al, 1977), crabs (Faghri et al, 1984), and water (LeChevallier et al, 1980(LeChevallier et al, , 1982Biamon and Hazen, 1983;Rippey and Cabelli, 1979). In contrast to much of the literature in which this organism is considered an undesirable part of the microflora of a food, Buttiaux (1959) has reported that Aeromonas plays an important role in the biological processes involved in the manufacture of a French raw sausage ('saucisson cru'). The presence of A. hydrophila in a food at spoilage suggests that the organism is capable of competitive growth at refrigeration temperatures (5°C).…”

Detection and Enumeration of Fecal Indicator Organisms in Frozen Sea Foods12

“…The greater resistance shown by these organisms, as compared with E. coli and other coliforms, to heating and freezing processes and to frozen storage has been cited as strong evidence supporting their use for this purpose (Larkin et al, 1955(Larkin et al, , 1956Kereluk and Gunderson, 1959b). Moreover, some doubt has been cast recently on the value of E. coli as an index of fecal pollution by the observations of Buttiaux (1959) and Young et al (1960) concerning the low recoveries of this organism from human feces. The enterococci appear to provide a good general index of fecal contamination and Streptococcus faecalis is believed to be a specific index of humaii pollution (Cooper and Ramadan, 1955;Barnes, Ingram, and Ingram, 1956), though findings quoted by Buttiaux (1958) cast some doubt on this conclusion.…”

Indicatori di qualità microbiologica e di sicurezza degli alimenti

“…Da un esame della letteratura, Battiaux concluse che il 100% dei campioni di feci umane e suine conteneva enterococchi, mentre solo l'86-89% conteneva coliformi 10 . E. faecium fu riconosciuto nel 1899 e ulteriormente caratterizzato nel 1919 da Orla-Jensen 64 .…”