Detection and Enumeration of Fecal Indicator Organisms in Frozen Sea Foods12

Abstract

Consistently high recoveries of enterococci as compared to the low numbers of coliforms obtained from the same samples of frozen sea foods are indirect evidence that enterococci are better indicators of contamination in such foods. The use of azide dextrose broth, modified by the incorporation of bromthvmol blue, and of ethyl violet azide broth as presumptive and confirmation tests, respectively, were found to be highly specific for the detection and enumeration of enterococci in these samples. Tetrazolium agar medium, when used as a third step after the confirmation test, provides a reliable differentiation of Streptococcus faecalis types from other group D streptococci. A simple procedure is described for further identification of S. faecalis varieties and other enterococcal species. Incidence of biotypes within certain species is noted and relationships of these subgroups to the organisms described by other workers is discussed. The striking resistance of all group D streptococci to dihydrostreptomycin and polymyxin B seems to offer promise for evolving a new selective medium for these organisms.

Prevalence and Antimicrobial Resistance of Enterococci Isolated from Retail Meats in the United States, 2002 to 2014

“…Because they are gut commensals in most vertebrates, enterococci are used as markers of fecal contamination of food products (10). Foodborne enterococci are rarely implicated as being directly responsible for foodborne infections, but the acquisition of these bacteria through food may result in intestinal colonization (11).…”

Comparison of the Recovery of Escherichia coli from Frozen Foods and Nutmeats by Confirmatory Incubation in EC Medium at 44.5 and 45.5 C

“…Nevertheless, the matter of the proper conditions and temperature of incubation of EC Medium is still subject to wide variation in America. Incubation of EC iMedium has been by either water bath or air incubator, at temperatures of 44.5, 45.0, or 45.5 C. Substances examined have been water, shellfish, and sewage (Perry and Hajna, 1944); water (Wattie, 1948;Geldreich et al, 1958); seawater (Tennant et al, 1959); precooked frozen foods (Shelton et al, 1961); and seafoods (Raj and Liston, 1961). There may well be more than one answer, depending upon the foodstuff involved.…”

Contribuição para o estudo da incidência de germes dos grupos coliforme e enterococo no leite e em alguns de seus derivados

“…É amplamente reconhecido que a contagem de coliformes pelo núme ro mais provável tem utilidade limitada para alguns produtos, de vido a origem diversa dos microrganismos incluídos no grupo coli forme, muitos dos quais derivam de fontes não humanas, podendo-se esperar normalmente a sua presença em certos produtos crus ou manufaturados. (30) assinalam, por outro lado, a insufi ciência dos coliformes quando usados para avaliar o grau de polui ção fecal de produtos congelados, como é o caso do pescado, enquan to H a h n & A p p l e m a n n (15) chegaram à mesma conclusão relati vamente ao suco de laranja concentrado e congelado. Efetivamen te, a pequena resistência dêsses germes às baixas temperaturas, faz com que sejam impróprios para a finalidade pesquisada, fato que levou alguns autores (K ereluk & Gunderson (19); L a r k in , L it s k y & F uller (20,21); Zabarowsky, H uber & R a y m a n (3 8 )) a advogarem o uso dos enterococos, em substituição aos colifor mes, como indicadores de contaminação fecal para produtos conge lados.…”